AN OVERVIEW OF FACTORS AFFECTING THE...

Techno Science Africana Journal, Volume 3 Number 1, June, 2009

AN OVERVIEW OF FACTORS AFFECTING THE CAREER OF ARCHITECTURAL TECHNOLOGISTS IN NIGERIA

Abdullahi, A. Kano University of Science and Technology, Wudil, Kano State

Email: [email protected]

ABSTRACT Architectural Technology as a programme started in the Nigerian polytechnics in the 1970s with the aim of training architectural technicians/technologists that will serve as intermediate manpower in both the private and public sectors. Even though the polytechnics have been producing technologists in this regard, there are some factors affecting the career of the technologists. This paper identifies the factors affecting the technologists, such as deficiencies in the course of training, limitation of progress in employment and employment opportunities. The paper reviews the curriculum prepared by the National Board for Technical Education (NBTE) and its implementation. It also looks at the Technologist in employment. In conclusion recommendations are made on how to enhance both the curriculum and government policies in respect of the employment of the technologists, so that they will have better prospects in both the public and private sectors.

Keywords: Architectural technology, career, curriculum, polytechnics, technologists, INTRODUCTION

Before the 20th century, architects then known as master builders handled all aspects of building from design, engineering and estimating to construction. However, with the technological development of the 20th century and complexity of the building industry, there was the need for specialization, which gave birth to new disciplines like civil engineering, quantity surveying and so on. Similarly, architectural technology came into existence in order to improve architectural services. When architects could no longer handle architectural demands due to the work load involved in the production of presentation drawings, working drawings, specifications, and contract administration and so on, it became obvious that they needed assistants in their offices. Initially, architects trained assistant architects in their offices who will complement their work towards a successful execution. The need for the institutionalization of architectural technology came up as an after mart of the 1958 conference on Architectural education, organized by the Royal Institute of British Architects (RIBA). The RIBA, in 1964 initiated and supported the establishment of the Society of Architectural and Associated Technician (SAAT) and in 1969 it became an associated society of the RIBA. The SAAT was later changed to British Institute of Architectural Technicians, and in 1996 this was also modified to British Institute of Architectural Technology (BIAT). Initially, the pre-requisite of becoming a member of BIAT is a diploma in Architectural Technology, now, with the upgrading of the polytechnics in Britain, to degree awarding institution, one need to have a degree in Architectural Technology which is mandatory to qualify as a member of the Institute. Architectural technology today in Britain is an area of specialization in its own merit, which one

may decide to pursue as a career and advance progressively either in the public or private sector, like in any other discipline. (Thompson, 1999). Nwanko (1999:20) in Usman (2003:96), define career as “the work in which individual expresses himself and relates to the society through work.” Another definition by the Longman Dictionary (2000:96) sees it as a “Job or profession that you have been trained for and intend to do for a long period of time”. Meriam-Webster’s online dictionary in Okpoechi (2006:8), defines career as a “field of pursuit of consecutive progressive achievement especially in public, professional or business life.” A more comprehensive definition which combines all the features of the above definitions, is the British Broadcasting Corporation (BBC) English Dictionary (1992) in Aniya and Lawal, (2006:28) that defines a career as “a type of job or profession that someone does for a long period of his/her life and in which he/she hopes to gain advancement.” In other words, a “career is any kind of discipline which brings means of livelihood, success and advancement” (Aniya and Lawal, 2006:28). According to Ogbimi (2002) in Aniya and Lawal (2006:28), the characteristics of a career are as follows:

a. identifiable course of life endeavour b. handwork c. educational success d. promotional steps (i.e. from consecutive

and progressive achievement ) e. full time occupation f. life-time occupation g. Means of livelihood.

However, one of the major characteristics of a career as stated above is missing in the case of the career of the architectural technologists in Nigeria, which is progressive achievement or advancement.

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This is due to some factors that are affecting the career of the technologists. The aim of this paper is to highlight the factors affecting the career of architectural technologist in Nigeria by identifying and discussing the factors, which has been discussed under three major headings: pre-training, training and practice. In order to appreciate the factors the paper set the scene by discussing role of Nigerian architectural technologist. THE ROLE OF ARCHITECTURAL TECNOLOGIST Initially the role of architectural technology as stated by BTEC (Business and technicians Education Council) is “to interpret, collate and present design information for use by the construction sector; collaborate with, and take instruction from the architect on the design requirements for a project” (Thompson, 1999).

The British Institute of Architectural Technologists (BIAT) 1988 year book shed more light on the role of architectural technologist as follows:

The architectural technician is principally an architectural technical communicator, forging the link between theory and practice. The technician’s role is therefore complementary to that of the architect, his main overriding concern being the sound technical performance of the building.

Prospects.ac.uk (2004) in discussing the role of architectural technologist succinctly puts it as follows:

Architectural technologists work in building design and construction management teams, working especially closely with architects. They have particular responsibility for ensuring the reliable technological performance of any building. They bridge the gap between the idea of an attractive functional building and the reality of that building performing successfully. They ensure that the right materials are used and the building meets building regulations and other legal requirements. They also monitor quality assurance, cost and the meeting of deadlines throughout the lifetime of a construction project.

They further stated that the Architectural technologists implement architects' design concepts by:

• analyzing the technical implications • assembling the data necessary to

complete architectural designs • using computers to prepare appropriate

design and working drawings

• co-ordinating structural, electrical and mechanical designs

• Preparing detailed instructions and specifications.

Under an architect's supervision, architectural technologists also may:

• prepare requests for quotations, cost estimates and contracts for projects

• represent the architect on the construction site, conduct site inspections, attend site meetings and prepare meeting notes, and ensure that the builder is complying with design specifications

• Instruct site managers or contractors about specific actions needed to correct design problems.

To understand the roles of architectural technologists that is expected to play, one has to review the training of the technologist.

As stated above, architectural technology as a programme was introduced in the Nigerian polytechnics in the 1970s with the aim of producing technicians/technologist that will fill the gaps of the junior and intermediate manpower in both the public and private sectors. With the establishment of the National Board for Technical Education (NBTE) in 1977, part of its mandate was the preparation of standard curriculum for architectural technology as it is offered in the polytechnics. In 1989, the NBTE produced the National Diploma (ND) and Higher National Diploma (HND) Curriculum, which is to serve as bench mark for all the polytechnics that offer architectural technology programme (Ahmed, 1999:1). The Goals and Objectives for the ND and HND programmes as stated in the curriculum are as follows: National Diploma (ND) The National Diploma programme in Architectural Technology is aimed at producing technicians for the architectural profession. The objectives are to produce a diplomat that will be able to:

1. Read, interpret and trace drawings 2. letter and stencil drawing sheets 3. scale , dimension, blow-up and reduce

drawings, 4. produce measured drawings 5. make good freehand sketches 6. produce basic presentation and

perspective drawings 7. build simple models 8. pront, forld and collate drawings for

submission 9. set out simple buildings.

Higher National Diploma (HND) The Higher National Diploma programme in Architectural Technology is aimed at producing higher technicians for the architectural profession and other sectors of the building industry.

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The diplomats of the HND programme will be able to:

1. Prepare space progrmmes and working drawings for architectural projects

2. design and prepare spatial relationship, circulation and area diagrams

3. develop and prepare design drawings 4. read and interpret technical drawings

and specifications and incorporate such details in the architectural working drawings

5. supervise construction works and make progress reports on simple structures

6. Make presentation drawings of architectural works and draw detailed perspective with necessary renderings and requisite colour scheme.

7. make detailed architectural models 8. Undertake preliminary site investigation

in relation to orientation, landscape, environment, soil form, etc.

9. Collect information and data on simple architectural projects.

10. Write specifications for simple building projects.

From the above, the intent of the curriculum designers is unambiguously spelt out i.e. the technologist is trained to play the role of architect assistant as obtains in Britain, where the concept was borrowed. In other words the technologists are trained to work hand-in- hand (complementary) with architects as partners in progress, each one having a defined role towards the successful execution of building projects from inception to completion.

However, this is not the case, as Suleiman (2006:32), observed that “in practice, the polytechnic graduate does almost the same work with the university graduate whether in the private sector or in the public sector, the difference being mainly in nomenclature”. Ahmed (1999:4) also shares this opinion as he observes that “in a lot of cases it cannot be differentiated between a polytechnic graduate and the university graduate in terms of work input, except in qualification.” This tells us that the above goal of training technologists has not been achieved. This is a pointer that the technologists are bound to face problems in their career as their training seem to be deficient. Coupled with this are other factors that are affecting the career of the technologist, which is the subject of discussion in the next section. FACTORS AFFECTING THE CARRIER OF THE TECHNOLOGIST The author used his 17year experience as architectural educator and project manager, discussion with architectural educators (lecturers and instructors), and architectural technologists in employment, and review of literature in identifying the factors that are affecting the career of the technologist. The factors can be

classified into three; pre-training, training and practice. Pre-Training Stage Most of the diplomates that the author discussed with have reveled that before given admission they could not differentiate between architecture and architectural technology. When given admission they thought that they were going to study architecture. Most of them claimed that they only came to know about the difference at the HND level or during their NYSC. This is to say that there is lack of awareness and proper career guidance. In other words, there is lack of career guidance before the commencement of the programmme Training Stage The factors that affect the career of the technologist at the training stage are as follows: Entry requirement Right from entry point the minimum entry requirements to study architectural technology in the polytechnic is four credits while for admission to read Architecture in the University five credits are required. This has negative effects on the career of the technologists as it gives an impression that architectural technology does not require much talent. Curriculum not well implemented The curriculum is not well implemented due to lack of proper understanding of the role the technologists are expected to play at the end of their training by the lecturers. Due to this, lecturers have grudges against the curriculum that its content, especially on design, is deficient, you find that what they teach in the case of design is contrary to the syllabus as obtained in the curriculum, with the belief that it will make the technologist compete favorably with the architect in practice. With respect to design, you find that there is no difference between what is being taught and what obtains in the university syllabus.

Another reason why the curriculum is not well implemented is the lecturers lack of motivation as a result of inferiority complex, resulting from the difference in the salary structure of the polytechnic and the university. Also, lack of the required necessary facilities hinders effective implementation of the curriculum.

One of the findings in a study carried out by Abubakar (2007:55), has shown that most of the department of architectural technology in the Nigerian polytechnics do not have a dedicated computer laboratory and where one is provided, the computers in the lab are not adequate for the required practicum within the duration of the programme and as such trainee are ill prepared in some way for contemporary practice, as architectural practice has been automated using

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the computer and virtual reality (Haruna, 2001: ; Baiyewa et al, 2007:75). Consequently, the technologist is neither fully trained neither as a technologist nor as an architect. Unqualified lecturers/instructors Most of the educators teaching architectural technology do not have teaching qualifications, although recently some institutions are making effort to remedy this. Lack of knowledge of teaching methodology hinders effective teaching and learning. According to Suleiman (2006:33), “…HND holders teach despite their nomenclature as instructors. Abubakar (2007:55) and Baiyewu, Jolaoso and Onaolaja (2007:75), corroborate this, and further stated that in some of the departments of Architectural Technology the number of instructors out weigh the number of lecturers who should actually be doing the lecturing/teaching. Accreditation /reaccreditation The Nigerian Institute of Architects (NIA) and Architects Registration Council of Nigeria (ARCON) do not pay accreditation/reaccredidation visits to departments of architectural technology in the polytechnics as they do in the case of departments of architecture in the universities. This is to say that they do not bother on the quality of training of the technologists. This is certainly affecting the career of the technologists as the NIA/ARCON may not come to the aid of architectural technologists on their problems in employment. Lack of Adequate Funding One of the major factors that affect the career of the technologist is inadequate funding to the polytechnic. For example most of the departments of architectural technology in the polytechnics do not have dedicated computer laboratories for Computer Aided Design and Drafting (CADD) practicum. Lack of adequate funding is the major challenge facing the training of the technologist, especially in the case of the government owned polytechnics where they only rely on the quarterly grant in running the departments, which is not adequate (Abubakar, 2007: 55; Baiyewa et al., 2007: 75). Practice Stage Societal recognition The society does not understand the role of architectural technology and as such does not appreciate the contribution of the technologist. The technologist is being looked at as an inferior architect. Professional recognition The NIA/ARCON may be said to have partial recognition of the Architectural technology programmes. As stated above, this can be seen in the non-charlant attitude it has shown in the

accreditation exercise of architectural technology programme. Limitation of career progression The technologist can not progress in his career beyond grade level 14 in the public service and one hardly finds a situation where the technologist is recognized and elevated to the position of a director in architectural practice. Suleiman (2006:33) observes that architectural technologists are “denied the opportunity to progress”. This limits the progress of the technologists.

Lack of avenue for further studies No arrangement is made for technologist for further studies after completion of HND apart from the post HND, which is only offered in two – three polytechnics out of the over 20 polytechnics in the country. Even with this, the diplomates cannot go beyond the post HND if they choose to remain as technologists. Other programmes which the technologists may utilize are not tailored towards architectural technology, they may have to switch to others cadre or go for further studies in architecture and end up as architects or something else (Suleiman, 2007:32) . CONCLUSION AND RECOMMENDATIONS The factors affecting the career of the technologist in Nigeria as discussed above constitute a major threat to not only the technologist but also architectural profession as well and on the long run the country will also suffer as they technologist may lack the requisite motivation to work towards national development, which is one of the goals of tertiary education in Nigeria (Federal Government of Nigeria, FGN, 2004). There is need for a solution to be sought so that the technologists can be rejuvenated, so as to facilitate successful architectural practice in the country. This will invariably contribute to national development and on the long run place Nigerian in its rightful position on the globe. In view of this, the following recommendations are made:

1. Government and private sector should lift the ceiling on the diplomat to advance to the highest grade level while in service.

2. Avenue for further studies should be created without the diplomat loosing their specialization.

3. the NIA should create the institute for architectural technologist to be known as the Nigerian Institute of Architectural Technologists

4. the admission policy should be reviewed so that the minimum entry requirement for the architectural technologist should be five credits just like that of architecture programme in the university

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5. the admission policy should be reviewed so that the minimum entry requirement for the architectural technologist should be five credits just like that of architecture programme in the university

6. government should ensure that all educators in the teaching architectural technology programme have the requisite teaching qualification

7. only qualified educators should be allowed to teach in the architectural technology programme

8. both State and Federal government should ensure adequate funding of the

architectural technology programme so that the department can effectively run their programmes

9. Computer aided design and drafting (CADD) should be included in the curriculum and CADD laboratory should be provided in all the departments of architectural technology.

10. In order to make the education and training of the architectural technologists relevant to the need of the Nigerian Building Industry, the curriculum should be reviewed after every five years.

REFERENCES Abdullahi A.(2001). The Role of Architectural

Educators in the Polytechnics in Nigeria. A paper presented at the AARCHES Valedictory Conference in honour of Professor E. A. Adeyemi, held between at Federal University of Technology, Akure.

Abdullahi, A. (2007). Condition of Architectural Technology Programme in Nigerian Polytechnics. AARCHES Journal, Vol 6 No 1, pp52-58.

Ahmed, S. S. (1999). The Role of Polytechnic Graduates in the Building Industry. A Paper Presented at a 2-day seminar/exhibition held at School of Technology, Kano State Polytechnic, Kano.

Aniya, J. U. & Lawal, A. T. (2006). Facilities Management: A Career for Architect Graduates and Implications for Curriculum Development. AARCHES Journal, Vol 5 No 1, p28.

Baiyewa, O. B. A., Jolaoso, B. A. and Onaloja, O. A. (2007). The Condition of Schools of Architecture in Nigeria Today: The Polytechnic Experience. AARCHES Journal, Vol 6 No 3, pp72-79.

Federal Government of Nigeria, FGN (2004). National Education Policy (4th ed.). Lagos: NERDC Press.

Haruna, I. A. (2001). Future of Architectural Education. A paper presented at the Nigerian Instituted of Architects (NIA) Biennial General Meeting and Conference

held on 23rd November, 2001 at Enugu, pp1-13.

Okpoechi, C. U. (2006). Equiping the Polytechnic Graduate of Architecture for the Reality of Self-Employment. AARCHES Journal, Vol 5 No 1, pp8.

Person Education (2000). Longman Active Study Dictionary. England: Person Education Ltd.

Suleiman, N. E. (2006). Towards an Intergrated Architectural Education in Nigeria. A Case for Postgraduate Diploma in Architectural Technology. AARCHES Journal, Vol 5 No 1, pp32-33.

Usman, D. A. (2003). Career Education and Career Development. In Saye, S. M. (Ed) Main Issues in Guidance and Counselling for Tertiary Institutions. Kano-Nigeria: Tunlad Prints and Publishing Co., pp 96, 105.

Thompson, A. (1999). Architectural Design Procedures. London: Arnold, a member of Hodder Headline Group.

National Board for Technical Education (1990). Curriculum and Course Specification for the National Diploma (ND) and Higher National Diploma (HND) in Architectural Technology.

Yoosuff, G. S. (2005). Conflicts in Architectural Education Curricula in Nigeria: Polytechnics Versus Universities. A paper presented at a seminar held on 26th September, 2005, organized by Department of Architecture, Kano State Polytechnic, Kano.

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ARCHITECTURE: THE CONCOURSE OF ART, SCIENCE, TECHNOLOGY, NATURE AND POLITICS

Abdullahi, A. Kano University of Science and Technology, Wudil, Kano State

Email: [email protected]

ABSTRACT

Architecture is appreciated as a result of the interplay of some elements/components. These elements are arts, science, technology, nature and politics. The concourse of these elements is what produces humane architecture. The interplay of these elements tends not to be directly straight forward in the realization of architecture. The paper unfolds the role of each of these elements in the concourse, by discussing the relationship of the elements in the making of architecture. The study reviews both published and unpublished literature from hard and soft copies. The paper concludes by emphasizing that each of the elements plays an important role in the making of architecture and that architects should consider having these elements proportionally in design, which will determine the dominant factor of architecture.

Keywords: Architecture, Art, Science, Technology, Politics

INTRODUCTION A civilization can best be understood by its architecture because of the way buildings show the interests of a society, its organizational skills, affluence or poverty, the kind of climate and the attitude towards technology and the arts. In towns and cities the general structure of society can be understood through the medium of architecture, so it becomes the most pervasive mirror of man’s presence. (Baker (1996: zxvii)

Right from time immemorial architecture has always been the concourse of arts, science, technology nature and politics only that one of these factors does play a dominant role depending on the period/time in question. This can be seen from classical to contemporary architecture.

The Chamber’s English Dictionary (1993:296) defined Concourse as the assembly of things/persons running together. This connotes the assembly of things in a competition. In other words, Architecture: The Concourse of Arts, Science, Technology, Nature and Politics connotes the elements coming together and competing with each other seeking for dominance. This is the process that produces architectural product as well as the challenge of architects at all times.

Thus as architecture is the concourse of the five factors mentioned above and will always remain so, (as there is no architecture without element of arts, science, technology, nature and politics), only one of the elements may play a dominant role in producing a product of architecture. However, where an architect neglects completely any of these elements it may result to bad or inhuman architecture. This paper discusses these elements on separate sections, though not in isolation from one another, but for the purpose of emphasis. It concludes by emphasizing that each of these elements is important in the concourse even though it may not play a dominant role depending on the goal an architect intends to achieve.

Architecture and Arts Langer (1953) asserts that “art is the creation of forms, symbolic of human feelings.” It is a creative act which produces the work of art. However, she stressed that to merely produce is not enough. In other words it must serve a purpose for which it is created and in the case of architecture the purpose is for exhibiting the activities of man. Thus, art in the mind of an architect begins with imagination and conceptualization that is brought into reality using drawings, models perspectives and so on. Art also is used as a medium of communication if implemented between the product and the people, which finally appears in 3-dimension. It is very important to note that man is the yardstick of measure in architecture. Unlike the other fine arts, where aesthetics plays the dominant role, in architecture both utility and delight are considered in the creation of a product of architecture.

The relationship of art and architecture brought about the emergence of styles in the 19th and 20th centuries, for example art and craft, art nouveau, art deco and so on. However, it should be noted that the creation above, is not sufficient to produce good architecture. This is because in creating a product of architecture other issues to do with the site have to be considered, which have to do with nature. The cultural values of the client and society have to be considered too. The technology which has to do with the stability and function of the product may also be a very important consideration depending on the nature of the product. In other words not only art but a combination of the other elements produces good architecture.

Below are plates showing how Arts play dominant role in the work of architecture. Plate No. 1 shows the interior gate of Emir’s Place, Kano. Plate No. 2 shows the Gidan Dan Hausa, Kano. The main element in both plates is the traditional motif that is commonly found in Hausa Traditional Architecture.

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PLATE 1: Interior Gate of Emir of Kano’s Palace

PLATE 2: Gidan Dan Hausa, Kano

Architecture and Science and Technology The twentieth century has been dominated by the relentless progress of science, and it is science that has provided mankind with ways of understanding and means of solving problems that have changed his perception of the world. Health, agriculture and food supply, communications and transportation, have all been transformed by the new technology, so that we now see the world through a scientific ‘filter’ as all-encompassing and pervasive as the power of religion in the middle ages. (Baker, 1996: 285)

Right from Egyptian to contemporary architecture science and technology has been playing a vital role in the development of architecture. But during the early period, science and technology was at its rudimentary stage and its influence on architecture was not as significant as it is today as it results in an improvement of quality of the physical environment in general. This was observed by

Baker (1996: 285) where he stated that “Man’s domination of nature, and opportunities created by science and technology that have been fuelled by capitalism, have improved the quality of life in materialistic sense”

The late 19th and 20th centuries were dominated by science and technology which resulted to total change in all aspects of human endeavor, architecture inclusive. The influence was more pronounced in the late 20th century where a style emerged known as the high-tech architecture.

The role played by science and technology in contemporary architecture affects architecture positively, in which it became possible to achieve the hallmarks of architecture (function, stability and delight), even though it may not be standalone. The 20th and 21st centuries became an era when construction techniques became a hallmark of style. As Richter (?, 118) stated, “here at last was a form

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of architecture that was truly liberated from historical reference,” where the influence of technology resulted in the emergence of a style -- high-tech architecture. However, even though technology is being used in achieving the hallmarks of architecture, it is good to note that this is to a certain extent. It did not replace completely the role played by the other factors (arts, nature and politics) for the emergence of a product of architecture. No matter the technology man has to use his subjective assessment in selection of the best proposal that meets the client’s needs. The nature of the environment determines other considerations (micro and macro climate), site characteristics and the cultural values of the people must continue to play a role for architecture to serve its purpose. Happold (1992: 28-31) confirmed this by stating that “even though Technology is about change, it is concerned with the development of useful objects or processes which change our lives. It does this in response to people’s aspirations or is restrained by people’s fears; in this it relates to the arts. What it does must obey the laws of nature.”

Plates 3, 4 and 5 below show the dominant role of Science and Technology in Architecture. Advanced science and technology influenced both the material used and construction technology without which the level of sophistication that make the work of architecture most interesting beginning from 18th

century to this 21st century could not have been achieved. Architecture and Nature

… Architecture is of the earth. It belongs to the ground as a container for the activities of man and as such is part of his very existence. This intrinsic link is evident in the basic need for shelter-buildings give shelter and in so doing engage architecture in man’s survival against the hostile forces of nature (Baker, 1996: xvii)

Nature provides the platform for the product of architecture as well a problem or rather a challenge for it to solve. For architecture to be relevant environmental factors that relate to nature must be considered in all aspects. This is in terms of micro and macro climate and site characteristics. Site characteristics will determine some aspect of function and stability and where nature is considered as a dominant factor it leads to the emergence of style, like in the case of ecological and organic architecture.

Even though nature plays a dominant role in the making of architecture, its response to the other elements makes a good architecture. The Falling Water designed by Frank Lloyd Wright (Plate No.6) and Villa Mairea by Alvar Aalto (Plate 7) are examples of how nature influenced some design parameters, playing dominant role in the works of architecture.

PLATE 3: Burj Al Arab Dubai, U.A.E.

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PLATE 4: 2008 Olympic Stadium “Bird’s Nest” Beijing, China

PLATE 5: Burj Dubai, U.A.E.

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PLATE 6: Falling water, Bear Run, Pennsylvania, U.S.A.

PLATE 7: Villa Mairea, Noormarkku, Finland

Architecture and Politics “Alone among the arts it (architecture) can express the idea of government, the church of the monarchy – it can also symbolize home” (Baker: xvii).

Our discussion in this section is going to be on politics as a dominant factor in architecture as Fawcett (1998: 4) observed that “… all architects work within an established socio-political framework which, to a greater or lesser extent, inevitably encourages or restricts their creative impulses.” This may be supported with the change of government in Germany in the 30s when Adolf Hitler came into power and saw the Bauhaus as working against the socialist ideas, which resulted to the closure of the Bauhaus and subsequently to the movement of progressive architects to Europe and America. Famous architects like Walter Gropius, Miers Van de Rohe had to be flown out of the country as the

then political climate did not suit the progressive architects. While in Russia the political climate was conducive for the constructivist, in this case the government supported the avant-garde of the Constructivism ideology. This also supported Fawcett’s (1998:4) assertion that “…architecture responds in some measure to a prevailing cultural climate in which it is created and therefore emerges inevitably as a cultural artifact reflecting the nature of that culture.” From what has been said so far, Architecture could be seen as a process and a product for the consumption of man. It is defined by its setting which determines its arts, science and technology, nature and politics. As observed by Malo (2002:1) “Architecture cannot be separated from the culture of its time – which includes political and social aspects.” Where Architecture refuses to take into cognizance the

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cultural values of the people, conflicts emerge which may result to non functional architecture. A good example of this is the case of Abuja, where foreign culture is being forced on the inhabitants by forcing the concept of shopping complexes. As shown above, the culture of man is being defined by its politics. Politics thus determines both the function and aesthetics of a particular architecture depending on the emphasis given by the client or society or government. In other words:

Architecture is communication from the body of the architect directly to the body of the

person who encounters the work (the users and the onlooker)…the architects’ ability to design a scheme is linked directly to the society for which it hopes to accommodate… good architecture is also a good sign of social acceptance of architecture perhaps (Hanlon (2003:1).

The National Assembly, Abuja in Plate No. 8 and United Nations Headquarters, New York, both are example of the influence of Politics on Architecture. These building serve as symbols of national and international politics respectively. Their concepts evolved as a result of the dominance of politics on architecture.

PLATE 8: National Assembly Complex, Abuja

PLATE 9: United Nations Headquarters, New York

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CONCLUSION The concourse of art, science and technology, nature and politics do shape architecture in order to achieve a particular goal. For architecture to play its roles, it must be relevant and continue to transform society positively, and hence the entire elements in the concourse should have a proportionate role to play in the making of

architecture, which will depend on the goal the architect intends to achieve. However, this will have to take cognizance of the need of the client, environmental, socio-cultural and political considerations, as well as the time, which will determine the extent of the role technology will play.

REFERENCE Appleyard, B. (1992). Understanding the present:

Science and the soul of modern man. London: Picador. P. 69

Baker, G. H. (1996). Design strategies in architecture: An approach to the analysis of Form (2nd ed). London: E & FN Spon, an Imprint of Chapman & Hall. P.307

Goggle Search (2005) worldview: The politics of architecture. http://www.worldviewcities.org/caracas/politics.html. Accessed on ?

Hanlon, B. (2003). Society, politics and architecture. Archiseek: Online architecture resources. ccessed on 27/9/05.

Happold E. (1992). Apersonal perception of engineering. London: RSBE Inc. pp 28-31

Langer, S. K. (1953). Feeling and form, A theory of art. London. pp.40- 54

Malo P. (2002). Message – Meaning and style. In design community architecture Discussion. www.design community.com/discussion/21220.html. accessed on 31/08/2002. P1

Norberg-Schulz (1969). Meaning in architecture. London: G. Baird. P. 22p

Pugh F. (1987). Design, engineering and the art of drawing. In D. Walker (ed). Great Engineers. London: Academy Editions, an imprint of the Acdemy Group Ltd. p.75

Richter K. (……?). Architecture: From Art Nouveau to Deconstrcutivism. Munich, Germany: Prestel Sightlines. P 118.

Riding A. (2002). Are politics built into architecture? http://www.nytmes. Com. Accessed on 30/08/02.

Schwarz, C. ed. (1993).The Chamber Dictionary. Great Britain: Chambers Harrap Publishers Ltd, p356.

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THE EFFECTS OF DIFFERENT LEVEL OF PHOSPHORUS ON QUANTITATIVE CHARACTERS/YIELD AND PRODUCTIVITY OF BAMBARA GROUNDNUTS (VIGNA SUBTERRANEAN L) IN YOLA

B.B Jakusko and M.D. Belel*. Department of Crop Production & Horticulture, Federal University of Technology, Yola.

* Department of Agric Technology, Federal Polytechnic, Mubi.

ABSTRACT The experiment was conducted during the 2006 cropping season at the Teaching and research farm of the crop production and Horticulture Department, Federal University of Technology Yola, Nigeria. The experiment was laid down using the Randomized complete block Design (RCBD) with four replications. The treatments consist of five levels of single super phosphate fertilizers: Control (No application), 40kg/ha, 50kg/ha, 60kg/ha, and 70kg/ha P

2O

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were evaluated against the growth and yield parameters studied which include: Establishment count, plant height, number of branches/plant, number of pods/plant, seed yield/plot, and seed yield/plant. The result obtained indicated a highly significant difference in number of pods per plant and seed yield per plot. The application of 60kg/ha P

2O

5 which gave the highest seed yield

per plant and seed yield per plot is therefore recommended for optimum production of Bambara Groundnuts in the study area.

Keywords: Bambara Groundnut, phosphorus levels, quantitative characters, productivity. INTRODUCTION Bambara groundnuts (Vigna subterranean (L.) Verdec)is a very important leguminous crop in both the tropical and sub tropical regions, it is commonly used as food in many household, and as components of feeds for many livestock(Sajo and Kadams,1999) The crop is indigenous to West Africa ,Probably Originated in Nigeria(Happer,1970). The Crop is an annual short creeping legume belonging to the leguminosae family and has a subterranean habit of growth (Cobley and steel,1975), Its growth is characterized by long petiole ,trifoliate leave which are produced from small hairy stems ,yellowish flowers ,and well developed tap root. Fruits are hard and wrinkled fruits mostly round or oval in shape. The seeds are smooth and hard with red or black color or sometimes with black edges (Toungos, 2007). The crop is a drought resistant (Duke et al,1977) and is best grown in well drained sandy loam soil with pH 5.0-6.5 and in areas with temperature ranges of 15-300 C with optimum rainfall between 600-1200mm per annum.(Duke,1981) Bambara Groundnuts is cultivated throughout the tropics because of its adaptation to areas of low rainfall and low soil fertility as well as being relatively resistant to pest and diseases compared to other leguminous crops (Doku & Karikari,1971;Duke,1981) Coudert (1982) estimated the world production of Bambara groundnut is about 330,000tonnes annually ,of which 45-50% is produced in west Africa, where Nigeria is the world leading producer with about 33,000-49,000 tons annually, followed by Mali with 33,000-39,000 tons per year. Other producing areas of Bambara Groundnut include: Ghana, Togo, and Niger Republic etc.

Bambara Groundnut is a versatile crop which contains 18.8% Protein, 6.25oil, and 61%

carbohydrate in dried seeds which can be consumed in an immature state after grilling or boiling. The matured seeds can be floured and used in making different kinds of food such as ‘Kosai’,and ‘Moimoi’, It has a tremendous potential in human diets,(Sajo and Kadams,1999). While the seeds and haulms are used as feeds for livestock. The crop is an important food crop that has received little attention and is grown mostly at subsistence level in most parts of West Africa (Viet Meyer, 1986). Very few research works had been carried out on the crop particularly on mineral fertilizer rates to increase its productivity. Rowland (1993), pointed out that information on the crop is pitifully small, more especially on the agronomy and physiology, much of which are in sources difficult to locate even in the country of origin. Although Stanton, (1968) suggested that high level of fertilizers can be profitable, the use of mineral fertilizers for the production of this crop has rarely been practiced. Information on the levels of phosphorus fertilizers for optimum Bambara Groundnuts production in the study area remains inadequate. This study was carried out in the field to validate the response of Bambara Groundnuts to different levels of phosphorus fertilizers.

MATERIALS AND METHODS The experiment was conducted during the 2006 farming season at the teaching and research farm of the Federal University of Technology Yola ,Nigeria, located between latitudes 90 30’N and longitudes 120 11’E at an altitude of 185.9m above sea level and lies within the northern guinea savannah of Nigeria(Nwagboso and Uyanga, 1999).. The mean annual rainfall of the area is 1044.35mm. Land preparation such as: land clearing, ploughing, and ridge making was carried out in late June using ox drawn ploughs.

13


The trial consists of five treatments (0kg/ha, 40kg/ha, 50kg/ha, 60kg/ha and70kg/haP

2O

5) in

four replications in a Randomized Complete Block Design (RCBD). The total experimental plot size was 540m2 , which was splitted into 20 plots .Each plot was made up of 5 ridges of 5m long. Planting was done on the ridges spaced at 30cm within rows on the ridge .A total of 80 plants were found on each per plot. The three inner

ridges constituted the net plots from which yields were measured. Weeding was done manually using hand hoes to keep the plots weed free. Phosphorus was applied in the form of single super phosphates (SSP) with 18%P

2O

5.

The fertilizers single super phosphates (SSP) were first incorporated into the soil by broadcasting prior to planting, at the rates indicated in Table 1 below:

Table 1: The rates of fertilizer application in kg/ha and kg/plot Treatments Levels(kg/ha P2O5) Rates(kg/ha ssp) Rates (kg/plot ssp)

1 0 (Control) 0.0 0.0 2 40 267.0 0.4 3 50 333.0 0.5 4 60 400.0 0.6 5 70 467.0 0.7

The variety Kwapurtu (KPT) was used for the experiment which was obtained from local farmers. Planting was done by placing single seed in each hole at a depth of about 5cm on the already made ridges .The seeds germinated at about 7 days after sowing. At harvest, the following parameters on the yield and yield components were measured: Establishment count, Plant height, Number of branches per plant, Number of pods per plant, seed yield per plant and seed yield per plot. The means were separated using Least Significant Difference (LSD), according to Gomez and Gomez (1984)

RESULTS The mean values for the six characters studied are presented in table 2. Other characters studied

but not discussed in this paper include: number of leaves/plant, establishment count, thickness of stems(mm), number of flowers/plant, days to 50% flowering, and leaf width(mm) at 10WAS . These parameters were measured primarily using physical count and the digital vanier calipers.

The result show that a highly significant difference between the treatments for plant height and number of branches, and a significant difference for number of pods per plant gave a significant difference between treatments at 5%levels of probability. There was no significant difference between the treatments for stand count, seed yield per plant and seed yield per plot.

Table 2: The mean values for six response characters to fertilizer application on Bambara Groundnuts (Vigna subterranean L.) Source Df Final

stand count

Plant Height

No of branches per plant

No of pods per plant

Seed yield per plant

Seed yield per plot.

Replication 3 15.9 0.63 333.80 414.10 101.80 237993.4 Treatment 4 51.1 5.75** 1433.30** 56.30* 17.60 40300.7 Error 12 65.1 0.19 256.60 304.80 44.4 77624.3 Total 19

*= Significant at 5% level of probability, ** = Significant at 1% level of probability. The number of branches per plant ranges from the mean values of 126.1 to 132.3 for the different treatments against the control mean of 86.7(Table 3).This gives highly significant difference between the treatment means for number of branches per plants. The result also show that a highly significant level of probability for plant height with mean value ranges of22.9cm to 24.9cm for the treatment against the control mean of 21.9cm.The number of pods

per plant recorded a significant difference between the treatment means (41.2 to 45.8)as against the control mean of 33.2. There were no significant differences for seed yield per plant and per plot. Also the Establishment not shows any statistical difference between the means of the different fertilizer levels and that of control. Thus, indicating that fertilizers did not have effect on the stand establishment of Bambara Groundnut.

Table 3: Mean values for growth and yield of Bambara Groundnut on Application of Single super phosphate fertilizers. Rates(Kg/ha P2O5)

Final stand count

Plant height (cm)

No of branches per plant

No of pods per plant

Seed yield per plant(g)

Seeds yield per plot(g)

Control 0 71.3 21.9 86.7 33.2 25.6 840.0 40 73.3 24.9 126.1 41.2 28.9 941.3 50 64.8 23.6 132.3 42.2 28.0 977.6 60 72.0 22.9 129.8 45.8 31.3 1107.3 70 67.8 24.5 126.6 42.5 29.6 1034.8 LSD 12.4 0.7 24.7 7.8 10.3 429.5

14


DISCUSSIONS Uptake of nutrient, especially phosphorus in the soil is a slow process,(Tanimu,1980)which may be as a result of its slow release , and may likely be a factor responsible for its less impact on the plant establishment count in this trial. The control plot with a mean stand count of 71.3 is not statistically different from the treatment means ranging from 64.8-73.3. The number of branches per plant in the experiment for all the levels of P fertilizers were statistically higher (126.1-132.3) than the control(86.7) ,which shows the effects of P fertilizers levels on the branching in Bambara Groundnuts ,this may be attributed to increased solubility of nutrients due to increased rainfall(Alabi,2004). However, the different fertilizer levels were not statistically different from each other. Ravankar and Badha (1975) also reported significant increase in yield components at all levels of phosphorus (40, 80,120kg P2O5/ha) application as compared to untreated control plots. Toungos(2007) also reported an increase in grain yield of Bambara Groundnuts with increase in P- Levels up to 60kg/ha. Plant Growth without phosphorus was poor and maximum seed yield gave 0.97 tons/ha whilst at a high P level, it was 3.96 tons /ha. Similarly, number of pods per plant showed that all the levels of fertilizer were statistically higher (41.2-45.8) than control (33.2). Other parameters such as establishment count, seed yield per plant, and seed yield per

plot were all not statistically significant as the levels of phosphorus did not influence their performance, which tends to be buttressed by the findings of Tanimu and Yayock (1989) that the rate and source of phosphorus did not significantly affect the phosphorus content and uptake of Bambara Groundnuts. However, the application of 25-50kg P

2O

5 /ha significantly

increase grain and haulms yield. No similar response of the crop application of 60kgP

2O

5/ha

(Tanimu, 1980). Similar result was obtained by Romolemana (1999). Kalyan et.al, (1989), also reported to support the result of increase in number of branches as well as number of pods per plant by the crops response to increasing levels of P- fertilization up to 90kgP

2O

5/ha.

CONCLUSION AND RECOMMENDATIONS Phosphorus nutrition is essential for the optimum and economic yield in Bambara Groundnuts .Thus these studies were conducted to establish the P- level for optimum and Economical crop growth in the study area. Based on the outcomes of the research, it can be concluded that the 60kgP

2O

5 /ha which recorded

the best outcome, can be recommended for an economic and optimum crop yield. This recommendation is backed by the findings of Stanton (1966), that it is economical to apply super phosphate at planting time or later at a rate of60kgP

2O

5 /ha.

REFERENCES Alabi,D.A (2006). Effects of fertilizer phosphorus

and poultry droppings treatments on Growth and nutrient components of pepper(capsicum annuum L.) African journal of biotechnology 5(8) pp.671-677

Cobley,L.S and Steel, W.M (1975) An introduction to Botany of Tropical crops 2nd edition Longman publishers, London Pp 101-102.

Coudert, M .J.(1982). Cowpea and Bambara Groundnuts;’Prospects for Regional trade Development in West Africa’ ,FAO,Geneva,Switzerland. P125

Doku, E. V. and Karikari, S K (1971). Bambara Groundnuts. Economic Botany25(3):255-262.

Duke,J.A. , Okigbo,B.N. ,Reed, F.C., and Weder,J.K.P.(1977). Voandazeia subterranean (L) Thurs . Tropical Grain Legumes Bulletin.Pp.8-11

Duke, J. A(1981). Handbook of legumes of world economic importance. Planum press, New york USA Pp307-310.

Gomez K. A , Gomez A.D.(1984). Statistical Procedures for Agricltural Research 2nd Ed. John Wiley and sons Sangopare DC . P.680.

Happer, F.N,(1970) Bambara Groundnuts(Vigna subterranean L. Verde).Field Crop abstract .23(1) 1-6 .

Kalyan S.,Singh,M.,and Singh,R S. (1989) Legumes Res. 1 (2):81-91.

Nwagboso, N.J. and Uyanga, J. (1999), Population. In: Adebayo A.A. and A.L. Tukur (Eds.) Adamawa State in Maps. Department of Geography, F.U.T. Yola. Pp 92.

Ravankar,H.N.,and Badha N.N. (1975). Punjab Krishi Vidya Peeth Res.J.3:145-146

Ramolemana, G, (1999) phosphorus Application to Irrigated Bambara Groundnuts In: Spores No:82 P.7.

Rowland, Jr. T.(1993).Dry land farming in Africa, first publication Macmillan, Longman And Bashingstone. Pp 278-282.

Sajo A A and Kadams A M (1999). Variability and Correlation Study in Yield and Yield Components of Bambara groundnuts(Vigna subterranean L. Verde).Journal of Applied Science and Management vol.2 Pp 66-70.

Stanton,W.R.(1968).Grain Legume in Africa,Pp183,FAO ,Rome,Italy Yearly Report.Pp11-58, 128-133.

Tanimu, B (1980). Bambara Agronomy In: Cropping Scheme Report (1989), Institute of Agric. Research, Zaria. Nigeria Pp 136-140.

Tanimu B and Yayock , J Y.(1989) The effects of NPK Fertilisers on the grain yield of Bambara Groundnuts (Vigna subterranean L verde)at samara In: Cropping Scheme meeting 1990,

Legumes and oil seed programme IAR/ ABU,Pp111-113.

Toungos,M.D (2007) ‘Effects of sowing dates and levels of phosphatic fertilizers on the performance of Bambara Groundnuts in Yola’ Ph. D. seminar Department of crop Production & Horticulture, FUTY.

Vietmeyer,N.D.(1986). Lesser Known Plants of potential Use. Agriculture and Forestry Science. Pp.1379-1384.

15


AN ANALYSIS OF WOMEN SATISFACTION INVOLVED IN INTER-LOCAL GOVERNMENT AGRICULTURAL PRODUCE MARKETING

IN KANO STATE

Sabo Ahmad Saíd and Isa Chiroma Audu Bako College of Agriculture, Dambatta

[email protected]

ABSTRACT Inter-local government agricultural produce marketing has been noted as a way to foster economic prosperity and market integration particularly in Kano State and the country in general. It is well known fact that the role of women in development of the economy and poverty alleviation of the State as well as the country can never be overemphasized. It is therefore against this background that the study seeks to estimate the level of satisfaction derived by women involved in inter-local government agricultural produce marketing in Kano State. The study was conducted in Dambatta, Rimin-gado, Gezawa,Wudil and Kura markets of kano state. A double stage random sampling technique was employed in drawing sample for this study. The logistic distribution model was used to analyze the data. It was found that the level of women participation and satisfaction was responsive among other factors to source of finance, age and level of income.

Keyword: Logit, Marketing, Satisfaction, women INTRODUCTION Inter-local government trade or marketing in Nigeria promotes market development and produce marketing specialization (Damisa, 2006). Therefore, agricultural produce trading will in no small measure assist in self employment and alleviation of poverty which will subsequently contribute to national growth and development. It will also expand market size and provides markets for domestic cottage industries which often play a crucial role in resolving food security issues. Thus inter-local government agricultural produce trading continues and government policies that influence them are vital components of economic growth and development (Haramata, 2002).

Nigerian women have been noted to be actively engaged in trading long time ago. In fact, trading has been the most important activity of women outside home and they account for half of the labour force in trading particularly in Yoruba land (Boserup, 1970’ Adeyokunnu’1980). Due to the fact that women are assumed to play second fiddle and that inter-local government trading is mostly carried out informally in the country, estimating the level of women contribution to national and regional economic development is quite difficult in Nigeria. Yet the role of women in the economic development of the country cannot be ignored (Sa’adu 2002). Women make a significant contribution to food production, food processing and marketing, they also provide about 60-80 percent of agricultural labour and are responsible for 80% of food production in the country (Ingawa, 1999). Their contribution to national income not withstanding, women usually have limited access to resources and opportunities, hence their productivity

remains low which subsequently result to low income, low saving and low investment. This study therefore intends to determine the nature and extent of women participation and satisfaction in inter local government agricultural produce marketing in Kano State. MATERIALS AND METHODS The study was conducted at Kura, Gezawa, Danbatta, wudil and Rimin Gado markets of Kano State. A purposive random sampling technique was employed in drawing sample for this study, this was done so as to cover the state. The sample frame for each market ranges between 200-300. 150 women, (30 from each market) were randomly sampled. Data were collected using structured questionnaire. The information collected include educational status, age, household size, security of life and property, transportation, source of finance and income of the marketers represented by Xj (the independent variables) while level market satisfaction is represented by Y (the dependent variable). The variables were measured as indicated under the model specification. The data so collected were analyzed using the dichotomous logit regression model. This model is preferred over the linear and probit dichotomous model because according to Green (2000). 1) Logit model ensures prediction of probability

of choice in the range of 0 and 1 (data value is binary)

2) The model unlike the probit model is based on the cumulative distribution function there by making it easier to compute and interpret.

It is stated as follows:- P(Yj = 1/Xj) = 1/1+e(-ά0-ß0xj)………………(1) P(Yj=0/Xj) = e(-ά0-ß0xj)/1+e(-ά0-ß0xj)…………(2)

16


Where P = Probability of occurrence Yj = jth dependence variable Xj = jth independence variables E = exponential function of 1 = 2.72 ά

0 and ß

0 = unknown parameters to be estimated

:- P(Y; = 1/xy) = f(ά0 +

ß0xj) ……………. (3)

while f(x) = 1/1+e (-x) …………………………..(4) equation (4) is the distributive function of the logit, hence, the name logit model. The conditional probability involved is F(y/x

j, ά

0, ß

j )

F(ά0 +

ßj Xj)y [1-F(ά

0 + ß

j Xj)]1-y

F(ά0 +

ßj Xj) if y =1

1-F(ά0 +

ßj Xj) if y =0

Therefore, Y = 1 if jth woman is satisfied Y = 0 if jth woman is not satisfied Xj – 1-8 are the socio-economic characteristics of the ith woman defined as X

1 = age (years)

X2 = level of income (N)

X3 = experience (years)

X4 = household size

X5 = level of education

X6 = security of life and property (low, average, high)

X7 = transportation (N)

X8 = source of finance (1-4) 1 = if personal saving, 2 = if relation, 3 = if money lenders, 4 = if

financial institutions. Age (X

1) refers to the number of years accrued to

the respondent from birth till date. It is expected that the older the woman the more access she has to information and technology. It could also be argued that with age, individual must have accumulated more capital (Ceteris Paribus) which could be recycled into the business. However, it may be possible for younger individual to participate more in marketing since they have more energy that could be spent on the activities of the business. The level of income (X

2) measures the

wealth status of the traders, in naira. It is expected that the sign of this coefficient be positive. The higher the value of X

2 variable, the

greater is the level of involvement of the woman in the inter-local government trade (ceteris paribus). This is because the level of income of the trader determines to a large extent the degree of her purchasing power. This means there is positive correlation between income which accumulates as a result of profit margin and amount saved. The level of experience (X

3 ) refers to the number of years the woman has

been engaged in marketing or trading. This can be linked to the age of the woman such that older women in the business tend to have more experience. It is expected that women that have more experience to participate more since they are more conversant about the market. Household size (X

4 ) is the total number

of individuals who live within and feed in the same house. This comprises of the woman and her husband, their children and other dependants. It is expected that women with large household will be driven by the desire to alleviate the economic crunch in the family by participating fully in the trade.

Educational status (X5 ). This is a variable

that measures the level of knowledge acquisition which could either be formal or informal. This could be positively or negatively related to the level of the woman participation in inter-local government trading. It is possible for women who have acquired more education to seek for white collar jobs that are thought to pay better than trading. It is also possible for women to have acquired more education just enough to have better understanding of the trade and therefore be more involved and satisfied in the business. Security of life and property (X

6 ). This

refers to the level of exposure of women to the hazards associated with trading. Such trading hazards include the rate of accidents and armed robbery on the way. It is expected that high level of insecurity will force many of the women out of the business. It is however measured as a dummy variable that captures the women’s view on the issue. Transportation (X

7 ). This variable captures

the amount of money spent by the women on commuter from the point of goods purchase to the point of sale within the various local governments. It is expected that the higher the transportation cost the more the women will be discouraged or dissatisfied from participating in trading. Source of Finance (X

8 ). This variable

refers to money that is used by the women for undertaking the trade business. It is expected that the more difficult it is for the women to source fund the more they will be discouraged from involving in business. The marginal probabilities of factors determining women satisfaction in inter-local government marketing can be derived from the logit model

17


Using derivatives thus: dp(Yj=1/xj)/dxj =

ß

j f’ (ά

0 + ß

j xj) ………………………….(5)

F’ = the derivative of the logit distribution function. The elasticity of probability of women satisfaction in inter-local government trade was estimated in order to determine the responsiveness of the probability with respect to jth factor and this elasticity of probability of women satisfaction is defined as the percentage

change in probability to percentage change in the magnitude of factors influencing women satisfaction in inter-local government trading. It is the marginal effect of x

j on (p(y

j=1/x

j) such that

elasticity of probability is given by

dp(yj = 1/x

j)/dx

j = ß

j F’ (ά

0 +

ß

j ) (1-F(ά

0 + ß

j –x

j)

Where F’ = estimated probability of women satisfaction in inter-local government produce marketing.

ß

j = estimate of the logit regression coefficient with respect to jth factor.

RESULT AND DISCUSSION From the result obtained the likelihood index indicated that up to hundred percent (100%) of the total variation in the dependent variable (women satisfaction) was explained by the logit model (table 1). The –2log likelihood test was

0.0001, Cox and Snell R sq = 0.74 and Nagelkerke R sq = 1.00 indicating the goodness of fit of the model. 100% of the women traders were correctly classified by the model. The model chi-square was 67.3% and significant at 5% level.

Table 1: Summary of Statistic of the logit model analysis Number of women traders predicted 100%

Model chi square 67.3010 -2 log likelihood 0.0001 Cox and Snell R square 0.7400 Nagelkerke R square 1.0000 Source: Researcher’s Computations

The study observed that transportation, source of finance, income and security of life and property are positively and significantly related to women satisfaction in inter-local government produce trading at 5% level (Table 2). Women mostly use public transportation to transfer their goods from one local government market to another. The women however, complained about the inefficiencies of the transport system. As a result of this draw back women trader face frequent delays in produce delivery thereby causing perishable consumable items to loose values. In overcoming this problem, women food crop traders organized themselves into group and negotiate the easy passage if their goods using freight forwarders. Table 2 indicates that the odd ratio associated with income level is 19.798; this brings about a probability change of .95 in the level of satisfaction and participation of the women in the trade with just a unit improvement of the variable, the odds ratio associated with transportation was found to be 8.369. It therefore implies that if the transportation system should be improved by a unit increase of its variable (x

7) then the odds that the women

traders becoming more satisfied in the inter-local government agricultural products trading (i.e. Y=1) increases more than eight fold all things being equal. This therefore means that the probability of women traders being satisfied with the inter-local government trading changes to 0.89 as a result of the transport improvement. If the transport variable further increase by two units then the probability of the women satisfaction and participation changes 0.99 which is quite a large response.

Most of the women traders complained that the profit they make is only barely enough to take care of their family needs, only very little is left which cannot help them save and expand their businesses. Source of finance (X

8) the odd

ratio associated with source of finance is 0.003 in the level of satisfaction and participation of the women traders with just a unit increase of the variable. In times of capital need, the women traders turn to their only source which are; relatives and traditional money lenders. These sources only provide a small amount of credit with very large interest and often short-term repayment period. There is an inverse relationship between the traders’ satisfaction/participation and source of finance coefficient. This is because most women traders do not have access to modern credit facilities from conventional financial institutions.

Security of life and property (X4) the odd ratio associated with security of life and property is 6.167 and this bring about probability change of 0.33 in the level of satisfaction and participation in their trade with just a unit improvement in the variable. The women traders complained of increased incidence of physical assaults and robbers while en-route markets, they therefore travel in groups to ensure their security while others have stopped traveling to some specific markets they consider as high risk zones. The marginal probabilities of the significant factors influencing women participation and satisfaction in inter local government trade were also estimated at three levels of the significant factors based on

18


equation (1) and the result is presented in table 4. Table 2: Maximum likelihood estimates for the factors determining women participant and satisfaction in inter-local government agricultural product trading in Kano state.

Factors Coefficients Exp (B) Age (X

1) -3.346(1.956) 0.035

Level of income (X2) 2.983(1.003) 19.789*

Experience (X3) -3.503 (1.801) 0.030

Security (X4) 1.815 (0.236) 6.167*

Educational level (X5) -13.127 (8.518) 0

Household size (X6) 0.152 (0.092) 1.169

Transportation (X7) 2.127(0.688) 8.398*

Source of finance (X8) -6.020(2.123) 0.003*

Constant -2.296(1.754) 0.101 Figure in parenthesis are standard errors , * = significant at 5% level and source of finance coefficient. The marginal estimates were done to view the extent of influence of significant factors on women participation and satisfaction in the agricultural product marketing across the local government. The participation and satisfaction was more responsive to source of finance, followed by level of income, transportation and lastly security as indicated in table 3. It is important to note here that even though women are more responsive to source of finance (X

8), the

odd ratio associated with it is just 0.003, in other words the probability that a unit change in source of finance will bring about participation and satisfaction in the women marketers is only 0.003, ceteris paribus. This however, is quite low. This means improvement in the source of finance variable without improving on the other significant factors will not improve the women’s participation and satisfaction in agricultural produce marketing.

Table 3: predicted probability of socio-economic factors affecting women participation and satisfaction in inter-local government trade in Kano state. Factor Min Avg Max Avg marginal

prob. Avg elasticity of prob

Source of income (X2 ) 1 2.96 6 0.472 1.739

Security of life & property (X

4 )

1 1.66 3 0.287 0.593

Transportation (X7) 1 3.98 5 0.337 1.667

Source of finance (X8) 1 3.14 5 0.952 3.724

Probability 0.71 0.80. 098 NA N.A From the result obtained, the age (X

i) of the active women traders are in the range of 21 to 60 years as

indicated in table 4 below which means agriculture produce marketing is mostly undertaken by young and middle age group. (about 79%).

Table 4: Distribution of respondents by age. Age Frequency Percentage

0-20 15 10 21-40 70 47 41-60 44 32 61-80 15 10 81 and above 1 1 Total 150 100

Source: Field survey; 2007/2008. The educational status (X

5) of the women involve

in agricultural produce marketing are mostly Non-formal and Primary school leavers as indicated by the table below. It therefore possible for women who acquired education beyond

primary school to seek for white scholar jobs that are thought to pay better than trading. But those women with secondary certificate and above might understand the trade and the opportunity therein more than their counterparts.

Table 5. Distribution of respondents by their educational status.

Status Frequency Percentage % Non-formal education 115 77 Primary education 27 18 Secondary education 5 3 Higher education 2 1 University education 1 1 Others - - Total 150 100

Source: Field survey; 2007/2008.

19


The women involved in inter-local government trading in the study area were found to be mostly engaged in various forms of agricultural commodity marketing (Table 6) The main agricultural produce being traded within and outside the local governments is food crop as seen in table 6. This might not be unconnected with high demand for food. This demand has increased with late commencement of rain and its early cessation in 2007. Across the

extreme northern states of Nigeria, (which include the study area). But this according to traders means brisk business which may lead to good profit as they buy during the harvesting period at cheaper price and sell at off season period when the demand is high. The trading of vegetables and fruits is seasonal. While poultry, livestock fishring and others (like tomato, pepper cassava, G/nut oil etc.) is throughout the year.

Table 6: Distribution of respondents by type of commodities they trade

Agricultural; products traded Frequency Percentage Food crops 65 45 Vegetable 7 5 Fruits 8 5 Poultry 15 10 Livestock 25 17 Fishers 19 13.5 Others 8 5.0 Total 150 100

Field survey 2007/2008 Table 7 indicated that 50% of the women traders were retailers. This group do not travel across local government borders but rather reside in the local village market where they participate in trading activities of market days. Most of the retailers own the business. The women traders deal basically on food crops, and travel to rural markets to purchase commodities in bulk and they constitute 30% of the women trading. 20% of the women traders are wholesalers, the only

difference between wholesalers and Retailers is in volume of goods purchased. The satisfaction derived from inter-local government trade can be determined in terms of their effectiveness and efficiency of their trade performance. Constraints such as income, family size and transportation can make women to be dissatisfied with their involvement in trading (i.e. reduce their marketing performance).

Table 7: Distribution of traders by the level of their trade.

Type of trade Frequency Percentage Whole sale 30 20 Whole sale/Retail 45 30 Retail 75 50 Total 150 100

Source: Field survey 2007/2008 Table 8 shows 61% of the women

sampled are dissatisfied with inter-local government agricultural commodities trading because of insecurity of life and property and lack of finance. The improvement in security and source of finance for the women involved in the trading requires examining the socio-economic constraints that affect their satisfaction and

participating in the agricultural commodities trading. 34% of the women traders are indifferent while 5% of the women traders are fully satisfied. These group their satisfaction might not be unconnected with the level of education and practicing modern trading which entail access to credit and extension services.

Table 8: Women Satisfaction/participation in inter-local government Agric Commodities trading Level of satisfaction/participation Frequency Percentage Very low 40 27 Low 51 34 Moderate 51 34 High 8 4 Very high 2 1 Total 150 100

Source: Field survey 2007/2008.

20


CONCLUSION The women’s response to the significant factors is quite elastic; meaning the small improvement in these factors could bring a wide improvement in the trade participation and satisfaction of the women. This will enhance the marketing efficiency of their produce. The level of income age and source of finance of the women traders were major constraints to the inter-local government agricultural produce marketing. In view of the economic significance and food security implication of the women trading activities, agricultural credit institutions, micro

finance banks and rural commercial bank branches under the Agricultural Credit Guarantee Scheme Fund should grant loans to these women traders under the canopies of women groups and cooperatives at low interest rates. This act could have a multiplier effect on the general improvement of agricultural produce marketing in the state and the country in general. The repairs and security of our railways, highways and major roads should also be improved by the government so as to reduce cost as well as the menace of arm robbery attacks on traders.

REFERENCES Adeyokunnu, T.O. 1980. Women and Agriculture

in Nigeria study commissioned by the trading research centre for women. Addis Ababa.

Boserup E., 1970. Women’s Role in Economic Development. Publisher. Earthscan Publication Limited, London.

Damisa M. A. and Tiku, N.E., An analysis of women participation in cross border trade in Northern Nigeria. Global Journal of Agricultural Sciences Vol. 5, No. 7 2006; 33-38.

Green, W.H. 2000. Economic analysis 4th edition. Parentice Hall International Inc.

Haramata,C, 2002; A Globalzing World Bulletin of the Dry land people, poles and programme. 41: 3-6

Ingawa, S. A., 1999, Welcome address at National workshop for women in agriculture held in FACU, Shehu-Abuja, Nigeria. 31st August – 2nd September

Sa’adu, B. 2002, Determinant of cross border trade. Regional Bulletin of Cross Border Trade Monitoring. Cotonou Benin, July – September.

21


BACTERIOLOGICAL EXAMINATION OF FRESH COW MILK IN DANBATTA AND MAKODA LOCAL GOVERNMENT AREAS

Isah, C. Department of Pre-national Diploma and General Science

e-mail Address: [email protected]

ABSTRACT Fifty 50 samples of fresh milk were collected from different livestock farms within the Danbatta, Makoda Local Government and Audu Bako College of Agric farm. The samples were examined for presence of potentially pathogenic organisms. Out of the 50 samples studies 42 (84%) were positive for bacteria and 8 (16%) showed no bacterial growth out of the samples identified with bacterial growth 35 (83.3) were positive for staphylococcus aureus 5(12.0%) streptococcus progenies and 2 (4.2oc) bacillus species. The results indicate that some lactating cows were subclinically infected with these organisms and that fresh milk may pose health hazards to the consumers.

Key words: Bacillus species, Milk, Pathogenic, Staphylococcus pyogenes INTRODUCTION Cattle are distributed throughout Nigeria with about two quarters of the population. Concentrated in the Northern states (Ajayi 1987). Cattle rearing is an integral part of cultural life and farming system of the rural people in this part of the country and hence animal husbandry has remained largely traditional. Cattle are being kept either for meat or milk as source of income or social status.

In Nigeria, diet of the rural population is highly deficient in animal protein, this deficiency has been compounded by the Sahel drought of the decade and the depletion of the cattle population by the recent out breaks of diseases. These loses in the cattle population has led to very high cost of beef, making it beyond the reach of the poor rural population.

However, in Nigeria there is increasing demand for fresh milk products (Lombin and Esievo 1979), but there is a short fall in the national fresh milk supply which necessitated the importation of large quantities of evaporated milk and other milk products annually.

Milk is regarded as a food of high nutritional value and its importance is based on the following. 1. It is a good source of protein, which is of

high biological value in promoting the growth of the young.

2. It contains useful vitamins, including vitamins A1, B1, B6 and vitamins D.

3. It is the best source of calcium in the diet and encourages sound bone and tooth development.

Fresh milk provide an excellent culture for bacteria and also serve as a vehicle for various dreadful disease agents to human beings, such as brucellosis, salmonelosis, streptococcal sore throat. Tuberculosis and other (Stack, 1953; Manthur M. 1962; Stoll, 1973; Smith and Roguinsky 1977; Guttierrz, 1982). The term mastitis refers to inflammation of the mammary gland regardless of the cause. It is characterized by physical, chemical and usually

bacteriological changes in the fresh milk and by pathological changes in the glandular tissue (Blood and Radiostitis, 1989), Mestitis affects milk quality causing some important changes of its physical properties such discoloration, presence of clots and presence of large numbers of leukocytes.

The aim of the study is to carryout bacteriological examination of fresh milk from cows in Danbatta, Makoda local Government areas and Audu Bako College in order to certain the following specific objectives. 1. To determine the type of organization in

fresh milk. 2. Identification of the isolated organism 3. To determine the public health important

of the organism isolated. MATERIALS METHOD Area of Study The collection of fresh milk samples was carried out in three established livestock farms in Danbatta, Makoda Local Government areas and Audu Bako College of Agric farm. Survey for Clinical Evidence The udder was subjected to a through physical examination which consists of visual observation and manual palpation of individual half of the udder and the teats. They were observed for asymmetry as evidence by atrophy variation in the size of the halves, variation in the heat position. The glands were palpated for induration, asymmentry not visible on scribed areas of fibrosis and survace labulation.

Teat ends were observed fro any change such as wounds, scars, patent teat orifice and ease of milking. Udder was also examined to ascertain whether the abnormality was unilateral or bilateral. Milk was expressed from individual half and examined for abnormalities such discoloration, clots of flakes, pus, blood staining or consistency where possible.

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Collection of Milk Samples Ten milliliters (10ml) of fresh milk samples were collected from mammary gland of a cow in a sterilized universal bottles, the samples were carried to the laboratory for microbiological analysis, and all the usual precautions were taken.

Bacteriological Examination of Milk Sample Three different solid growth media were used namely, blood agar, macconkey agar, and nutrient agar, they all oxoid products. The milk samples were inoculated on to three different agar plates by streak method. The plates were

incubated for 24hrs at 37oc, aerobically and were later observed for bacterial growth. Those plates with bacterial growths were further examined in order to identify the isolates. The isolated bacteria were identified using conventional methods as described by (Cowan and Steel 1970). RESULT A total of fifty (50) samples of fresh milk were examined, 35 (70%) found to contain Staphylococci aurues, 5 (10%) of the total samples showed no growth of bacteria.

Table 1:Type and frequency of bacteria isolated from fresh milk. Micro-Organism Total of Samples Number of Plates with

bacterial cells Incidence in Percentage

Staphylococcus aureus 50 35 70% Staphylococcus Pyogenes

50 5 10%

Bacillus Species 50 2 4%

DISCUSSION AND CONCLUSION Fresh milk is largely consumed in Northern part of Nigeria and most of this fresh Milk consumed is usually unpasteurised which make it a public health hazard. Little work has also been done on the microbiological safety of this unpasteurised fresh milk to ascertain the quality of the milk in relation to public health. In advanced countries, fresh milk has to be pastuerised before marketing by this method, the fresh milk is made pathogens free and also wholesome for public consumption. It is also known that fresh milk that is not pasteurized can be source of many zoonotic disease. This support the findings of this study. The isolation of two pathogens Staphylococcus aureus and Streptococcus pyogenes indicated that most of the fresh milk in different livestock farms at Danbatta, Makoda Local Government Areas and Audu Bako College of Agric farm is contaminated and this may act as source of infection to the public. Though, the organism isolated are ubiquitous in nature, the most probable sources of these organism could be from soil bed embedding the animal body and milking utensils.

The organism can easily gain access into the fresh milk during milking processes, thereby contaminating the milk. From the results obtained in this study, it shows that fresh milk is highly contaminated with various type of bacteria and consumption of such product can be of health hazard. Therefore is need for public education on the importance of boiling fresh milk before consumption. The milkers should observed strict hygienic measures in order to minimize contamination. Although, during the study, no clinical mastitis was observed, the result may further reveal that some of the animals are subclinically infected with the isolated organisms and these animals acts as a sources of the organism. In conclusion, the overall result show that unpasteurised fresh milk is highly contaminated with many pathogens. Consumption of such milk usually results in a number of disease such as sore throat scarlet fever in and around Danbatta, Makoda Local Government areas in different livestock farms and Audu Bako College of Agric farm.

REFERENCE Ajayi (1987) Sheep and goat production and health

management in Nigeria. Nigeria Livestock Farmer 7 (1-4):18:21.

Benjamin, M and Hughes O. (1975): Introduction to Foods New York Macmillan publishing Co. inc. PP 219-225 cited by Ogunde, A. O 1988. The appropriate technologist for milk and dairy produces processing in Nigeria. A paper presented at the 12th Annual conference of the Nigeria institute of food Science and Technology (NEST) at University of Maiduguri.

Blood, D.C and Radiostis, (1989) Veterinary medicine 7th edition English Language, book society Beilliere tindal 501-549.

Cowan S.T and steel K.T (1970): Manual for identification of medical bacteria. Cambridge University press PP 1-176.

Kalra, D.S (1987), Efficiency of various diagnostic test for mastitis, Journal of Research Iv (3): 449-455.

Lombin and Eseivo (1979) Cell counts of bulked milk supplies from dairy farm of Northern Nigeria. Tropical Animal Health and Production 171-174.

Mathur, an Rao (1962): Paindey J.N and mandell, L.N (1980) studies on the bacterial Floara of raw milk supply scheme patha, in relation to public Health. Indian veterinary Journal 57:47.

Shresth, B.O Tapps, J.N and Pratt, G (1972): In take and ingestion of barkey straw by sheep given expelled groundnut meet with different amount of calcium. Tropical Animal health production in Africa 4:165-172

23


CHANGES IN NUTRIENTS DURING STORAGE AND PROCESSING OF FOODS - A REVIEW

Dandago, M.A. Department of Food Science and Technology, Kano University of Science and Technology, Wudil, Kano

State [email protected]

ABSTRACT Various changes that occur in nutrients during processing and storage of various food products were reviewed. Preliminary unit operations such as cleaning, soaking, peeling and dehulling leads to significant losses of vitamins and mineral contents of food products. Applications of heat during processing also lead to losses quantitatively and qualitatively and it was noticed that water soluble vitamins were worst affected. Undesirable reactions in proteins which can lead to decrease in its biological value may also occur in some foods products. Sugars are affected by leaching and also take part in browning reactions. Irradiation is not suitable for fatty foods. Recommendations were made on adopting new/modern processing methods to decrease the losses. Proper storage conditions especially temperature and humidity controls should be adhered to strictly at the same time local producers/processors should be educated on consequences of over processing.

Key words: Nutrients, vitamins, dehulling, peeling, leaching, oxidation. INTRODUCTION Food is any substance assimilated into the body of living organism, which provides energy, material for growth, body repair, reproduction and assist in regulation of various processes in the body (Odeyemi and Duramola, 2000). Food is like fine China not only is it expensive, but it must be handled carefully because of its fragile nature. Food products are susceptible to spoilage, loss of nutrients, insects and rodents infestations, and changes in color, flavor and odor (Hurst, Reynolds, Scheler and Christian, 1993).

Storage is defined as holding goods until needed for further processing, marketing or consumption. The expression connotes the expectation that goods would not just be kept, but in the most appropriate conditions for maximum retention of both quality and quantity (Wajilda, 2008).

The term processing cover an enormous field of widely different treatments carried out to render food safe, edible and palatable. The major methods of preservation all cause some changes in the nutritional value of food but the loss is not significant. Nutrients are those substances in foods which when eaten provide nourishment to the body. The most sensitive nutrients to change are vitamin C and to a lesser extent vitamin B

1.

Other nutrients are much more stable and very little is lost in most processes. However, greater losses can occur due to improper storage of food under adverse environmental conditions (Hurst et al., 1993).

Cooking improves the digestibility of foods, promotes palatability and improves the keeping quality as well as wholesomeness. The heat used during processing can be a dry heat (as in baking) or wet heat (as in steaming). Heat helps to sterilize the food by killing harmful bacteria, control undesirable enzymatic reactions and enhance nutrients availability (Okaka and

Okaka, 2001). Proteins are denatured by heat where they are made more easily digestable by proteolytic enzymes and cellulosic cell walls that can not be broken down by monograstric animals (e.g. man) are broken down during heating. Heat also helps to inactivate anti-nutritional factors such as trypsin inhibitors.

There is significant improvement in quality and digestibility of carbohydrates after malting process and anti-nutritional substances in the grains are leached out. Soaking of cowpea prior to milling helps to hydrolyze the indigestible oligosaccharides. Foods are made more stable for certain period of time after drying, cold storage, irradiation, addition of preservatives etc however; despite all the advantages of food processing and storage there are adverse effects or changes that occur in the nutrients during some operations. There is need to understand these undesirable changes in food nutrients and take possible measures to over come them.

Changes in Various Nutrients: Changes in Vitamins and Minerals during storage There is every reason to believe that only insignificant level of vitamin B is lost during storage of frozen meats provided the temperature is low enough and does not fluctuate. The most susceptible vitamins are B

1

and B2.

Milk may lose substantial amounts of vitamins B

2. and C within few hours if stored in a

clear bottle in sunlight whereas vitamins A and D are not affected (Hurst et al., 1993). The vitamin content of cereals (rice and wheat) remains relatively stable provided the moisture content does not increase above 10%. The vitamin B content of stored bread and break fast cereals remains stable provided good storage conditions are used.

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Vitamins A and C are regarded as the most important nutrients in fruits and vegetables but substantial quantities of both vitamins are lost if kept at room temperature. Vitamin E which is highly susceptible to oxidation is found in substantial amount in nuts. The vitamin can be preserved by vacuum packaging or freezing the product in oxygen impermeable film (Hurst et al., 1993). According to Hurst et al, (1993) drying does not cause major losses in vitamins provided the finished food are adequately protected from oxygen either by proper packaging or use of anti-oxidants. Changes in Vitamins and Minerals during Processing Because of their essential nature, the extent of destruction of vitamins during processing is often the main criterion by which workers judge the quality of processed foods (Ihekoronye and Ngoddy, 1985). But it is often realized that home cooking generally lead to much greater loss of vitamins than those encountered in industrial processing. Generally, the skin of fruits and vegetables is richer in vitamins than other areas and also the bran of cereals grains contains the B vitamins. In tuber crops the surface is usually higher in vitamins than the cortex and consequently trimming, peeling, washing etc. of fruits and vegetables; root and tubers prior processing result in loss of vitamins and minerals. To understand the effect of trimming or peeling on the nutritional value of foods it is important to understand the distribution of vitamins on food materials. Vitamin C for example is higher in the peels of fruits and vegetables than in the cortex. Niacin and Riboflavin are also slightly higher in the peel of fruits. Fresh citrus fruits show much higher concentration of Ascorbic acid in the outer peel and inner white skin than in the fruit pulp or juice whereas in vegetables, vitamins are normally higher in leafy portions. In carrots for example, the peel is much higher in niacin and carotene than the remaining root. The same is true of palm fruit and potatoes which show vitamin higher content in the peel than in the flesh. There is no doubt that trimming and peeling of fruits and vegetables reduce the nutrients content, however boiling the food material with the intact skin helps to retain these nutrients (Leriei 1998).

In Nigeria, leafy vegetables and many

fruits are hardly processed and only small quantities of harvested vegetables are sun dried locally. Losses may occur with vitamins labile to heat, light and air (Ihekoronye and Ngoddy, 1985). Blanching is the first step for effective preservation of some fruits and vegetables and in many instances, blanching treatment is often combined with the use of chemicals in order to

produce certain desirable qualities. Loss of vitamins and minerals during blanching can be significant and is a function of surface area per mass of product, degree of maturity of the product, blanching method, blanching time and method of cooling after blanching. Nutrients losses that occur during blanching are caused by leaching, oxidation of water soluble nutrients and thermal destruction (Walter, Truond and Espinel, 1998). Both vitamin A and Carotene are unaffected by most cooking methods but small amounts may be lost during frying. Also about 25% of thiamin is lost when potatoes are boiled, meat looses about 40% of its thiamine content when roasted and also when bread is baked about 25% of the thiamine is destroyed. According to Ihekoronye and Ngoddy (1985), the overall loss of water soluble vitamins is greater than that of fat soluble vitamins during cooking. Preservation by freezing and storage of these frozen products is generally regarded as the best method for long term preservation when judged on vitamin retention. Losses that occur are generally not significant if proper packaging and freezing procedures are used. A loss in the ranges of 0-40% vitamins does occur in vegetables and animal tissues during frozen storage (Okaka and Okaka, 2001).

During flour milling, the outer coat where B complex vitamins and minerals are localized are removed in order to obtain flour of desirable texture (Asiedu, 1989). This necessitates flour enrichment with vitamins and minerals after milling. Changes in Proteins during storage The biological value of proteins is usually little affected by proper storage of food products. High storage temperature will cause certain amino acids (e.g. lysine) to chemically bind with simple sugars to form brown pigments through maillard reaction. The reaction affects the nutritional value of the food because it causes the essential amino acid to become physiologically unavailable (for example improperly stored dried milk and egg white powder are particularly susceptible to this browning reaction) the reaction will also occur if poor packaging of dried foods allow as increase in moisture level (Hurst et al., 1993). Changes in Proteins during Processing A number of changes may occur during processing, some of which are desirable while others are undesirable. Some chemical changes may lead to compounds which are non hydrolysable by the intestinal enzymes; or to improvement of nutritional value by deactivating certain anti-nutritional factors such as trypsin inhibitors (Ikeme, 1990). The types of changes in protein during processing are recognized as follows:

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1. Denuturation which requires mild heat is the unfolding of the protein complex structure, and according to Nielsen (2004) the effects of denuturation include:

(a) Peptide bonds of the protein are more readily available for hydrolysis by proteolytic enzymes.

(b) Enzymes activity if originally present is lost or decreased.

(c) Crystallization of protein is no longer possible.

(d) Intrinsic viscosity is increased. Afterall boiling and roasting of food materials

certainly denature the protein as indeed will the acid of the stomach, but there is no loss of nutritive value (Behsnilian, Regier and Stahl, 2003).

2. The second type of change is caused by mild heat in the presence of reducing substances which results in a linkage between the end epilson amino group of lysine with reducing substances which can not be hydrolyzed by the digestive enzymes. The lysine is still present and is liberated by acid hydrolysis, but since it can not be librated during digestion, it is biologically unavailable.

3. More severe heating reduces availability of other amino acids as well as lysine and can occur in absence of reducing substances. At temperature of 1150C, cystine is relatively sensitive and can be oxidized to disulphide or disulphene. Milk for instance is pasteurized at 720C for 15 seconds (Ihekoronye and Ngoddy, 1985). Changes in temperature and time will lead to off flavor production because of unfolding of β-lacto globulin. Consequently, there is exposure of sulphadryl groups of cystine for hydrolysis and production of hydrogen sulphide. Also light induced oxidation of proteins is known to lead to off flavor and destruction of essential amino acids in milk. Sunlight attacks methionine and converts it into methionol which cause a typical sunlight off flavor at 0.1ppm (Behsnillan et al., 2003). The source of light induced off flavor in milk resides in low density lipo protein fraction.

4. Excessive heat such as applied to the outside of foods of the puffing exploding type of processing used in the manufacture of some breakfast cereals and pop corn causes severe protein damage. It leads to the destruction of amino acids by complete decomposition or by forming of cross linkages forming poly amino acids. Temperatures of 1800C such as used in roasting meat, fish, coffee and biscuit baking have these effects (Ihekoronye and Ngoddy, 1985).

5. Alkali treatment in conjunction with heat treatment and oxidation damages protein quality. Alkali treatment is been used in preparation of protein concentrates and isolates. This treatment leads to the

formation of new amino acids such as Lysino – alanine, Lanthronine and ornithino-alanine. Cystine, lysine and serine are primarily involved in such reactions (Ihekoronye and Ngoddy, 1985).

6. Ionizing radiations is a modern method that is employed in food processing and preservation. These radiations can produce charged particles (ions) in the materials they strike and hence undesirable reactions may occur. In proteins, deaminations, oxidations, polymerization and decarboxylation have been observed during irradiation. Histidine, phenylanine, Tyrosine and sulphur containing amino acids are reported to be the most sensitive to the effect of irradiation (Fellows, 2000).

Changes in Lipids during Storage The nutritional value of fat lies in the energy it supplied to the body during digestion. Fats are fairly stable to processing (except frying) but may undergo quality deterioration during prolonged storage. Oxidation and hydrolytic rancidity occurs in stored foods leading to off flavor development. These reactions can be caused by enzymes or by moisture and air. They occur more rapidly under adverse conditions but can also develop in properly stored fatty acids. Lipids oxidation produces off flavor components called hydro peroxides and peroxides which react chemically with fat soluble vitamins rendering them nutritionally useless. Loss of these nutrients can be minimized by wrapping foods in moisture proof and oxygen impermeable packaging materials (Hurst et al., 1993). Changes in Lipids during Processing Excessive heating will cause reaction of carbonyl components resulting from the decomposition of unsaturated fatty acids which may lead to reactions similar to those involved in non-enzymatic browning. Lipases and phospholipases release fatty acids from meat and fish during frozen storage and free fatty acids are more susceptible to oxidative rancidity (Okaka and Okaka, 2001). This problem is especially important in products with high degree of unsaturated fatty acids (e.g. pork and sea foods).

Many irradiation promoted reactions occur in lipids and produce results similar to oxidative rancidity with loss in fat soluble vitamins. Several carbonyl compounds may be formed together with other potentially active intermediates that can be carcinogenic. Changes in Carbohydrates during Storage Carbohydrates can be said to be relatively stable to processing and storage compared to sensitive nutrients such as vitamins.

There is no significant loss in the nutritional value of carbohydrates in frozen, canned or dried foods.

26


Infact, some carbohydrates are made more digestible through processing and thus nutritionally available and complex carbohydrates are converted to simple sugars. Adverse brown pigments occur in frozen and dried foods when carbohydrates react with proteins (Hurst et al., 1993).

Changes in Carbohydrates during Processing During wet heat treatment as in blanching and boiling; there is considerable loss of low molecular weight carbohydrates as well as micro-nutrients into the processing water. The loss of glucose and fructose at boiling is higher than that of sucrose. The loss of low molecular weight carbohydrates also may vary between species and cultivars. Non enzymatic browning reactions occur between reducing sugars and amino groups in foods during processing and storage. These reactions are temperature dependent and most extensive at intermediate water activities (Leriei, 1998). They are important nutritionally as they may diminish the bio availability of amino acids especially lysine and thus diminishing the protein nutritional value. The carbohydrate content and availability is influenced only marginally. When starch is heated in the presence of water, the starch granules ruptures and form gels. The gelatinization increases the availability of starch for digestion by amylolytic enzymes. Gelatinized starch is not in thermodynamic equilibrium and according to Leriei (1998) there is therefore a progressive re-association of the starch molecules upon ageing. This recrystallization is referred to as retrogradation and may reduce the digestibility of the starch.

Changes in Moisture during Processing Changes in moisture content of dried and frozen food can affect the nutritional quality of food.

Increase in the moisture level of dried food promotes microbial deterioration and accelerate rancidity. Improperly wrapped foods suffer form freezer burn which is a form of dehydration from the food surface. This loss of moisture causes oxidation of fats and browning leading to off flavor development and at the same time lowering the nutritional value of the food (Hurst et al., 1993).

CONCLUSION AND RECOMMENDATIONS Processing foods is necessary to achieve desirable sensory and healthy attributes in the food product. Storage of food materials is also necessary to extend the shelf life of the product and make it available for future use and for processing. Because storage and processing of foods are inevitable, there is need to devise methods to at least reduce the adverse effects due to these processes. These effects can be reduced by the following recommendations: i. Strictly following the storage conditions of

temperature and relative humidity for the particular food product and also avoiding temperature fluctuations.

ii. Adopting high energy transfer processing method such as (HTST) to reduce the treatment time.

iii. Adopting new processing methods such as high hydrostatic pressure technology, ohmic heating, and ultrasound technologies where necessary.

iv. Improving temperature, humidity control and packaging systems in food storage and distributions

v. It is also recommended that the populace be educated on the effect of over processing on the nutrients and suggest possible ways to avoid it. This can be achieved through radio jingles and or use of extension workers.

REFERENCES Asiedu, J.J. (1989). Processing Tropical Crops.

Macmillan Educational Limited London. Behsnilan, D., Regier, M. and Stahl, M. (2003).

New methods in food processing. Federal Research Centre for Nutrition, Germany.

Fellows, P. (2000). Food Processing Technology: Principles and Practice. Wood Head Publishing Limited Cambridge.

Hurst, W.C. Reynolds, A.E., Schuler, G.A. and Christian, J.A (1993). Maintaining Food Quantity in Storage. University Of Georgia Cooperative Extension Service Bulletin 914.

Ihekoronye, A.I. and Ngoddy, P.O (1985). Integrated Food Science and Technology for the Tropics. 1st Ed Macmillan Educational Limited London.

Ikeme, A.I. (1990). Meat Science and Technology. Africana Fep Publishers Bermenda Cameroon.

Leriei, C.R. (1998). Influence of Modern Technologies Of Processing, Storage and Distribution Of Food Products. International Seminar on Nuclear War and Planetary Emergencies 23rd Session.

Nielsen, T. (2004). Underlying Principles and Actual Problems for the Processing Of Organic Meat Products. Organic e-prints. Denmark.

Odeyemi, O.O. and Daramola, A.M. (2000). Storage Practices in the Tropics. Vol. 1 Dare Collins Publications Akure. Nigeria Pp. 2

Okaka, J.C and Okaka, A.N.C. (2001). Food composition, Spoilage and Shelf life Extension. Ocjanco Academic Publishers, Enugu.

Walter, W.M., Tround, V.D. and Espind, K.R. (1998). Effects of Puree Processing Methods on the Textural Characteristics Of an Alginate Textured Sweet Potato Products. Food Science Research Unit. United States Department of Agriculture.

Wajilda, J.I. (2008). A Review Of Traditional Grain Storage Practices In Adamawa State. M. Tech. Non Thesis Seminar Department of Crop Production and Horticulture Federal University of Technology Yola (Unpublished).

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EVALUATION OF SLAUGHTER PRACTICES IN KANO ABATTOIR

Dandago, M.A.1, Farouk, S. U. 1 and Igwe, E.C.2 1Department of Food Science and Technology, Kano University of Science and Technology,

Wudil, Kano State. 2Department of Food Science and Technology, Federal University of Technology,

P.M.B. 2076 Yola, Nigeria.

ABSTRACT This study on Kano abattoir was carried out through oral and structured (Questionnaire) interviews and personal observations as well as use of documentary sources of information. Results showed that cattle, camel, goat and sheep are the animals usually slaughtered. There are negative abattoir practices such as absence of lairage rest and antemortem examination, crude immobilization of animals, unsanitary practices and callousness to fetal losses Others include inadequate postmortem examinations on the slaughtered animals, and militant and uncooperative attitudes of the animal owners. The good abattoir practices include method of cutting-up and byproduct processing. Postmortem rejects include liver, lungs, gastro-intestinal tract (GIT), hearts, kidney, udder, head/tongue and leg/hoof. It was observed that camel was the least slaughtered whereas postmortem condemnations were most in cattle and least in goats / sheep and camels Also recommendations were proffered on how best to improve slaughter practices in Kano.

Keywords: Post mortem, Abattoir, Lairage, Immobilization, Evisceration, Livestock INTRODUCTION The term public Abattoir according to Ikeme (1990) applies to the premises where the government or another public authority provides facilities for butchers and their employees to slaughter livestock and to dress the carcass meat and offal. The conventional arrangement has been for each town or city to have its own public abattoir where the community’s daily meat supplies can be prepared under suitable and under strict sanitary conditions.

The production, distribution and marketing of good quality raw and processed meat and meat products are the major preoccupation of the meat industry. This involves not only catcalling meat from the culled animals but also the handling, storing, preserving, processing, distributing and marketing of meat in wholesome condition. The extraction of meat from the culled animals is achieved in the abattoirs, slaughter houses, slabs and other killing grounds (Obanu, 1990). Abattoirs, slaughter houses and slabs are the key-points where the operators could have control over the conversion of animals to meat so to ensure hygiene and quality. Standard abattoirs should have qualified personnel, state-of-the-art equipment, lairage, adequate and potable water supply, good drainage and efficient sanitation system. The floors should be cemented, while roofs should be present to detract birds and insects, trees and bushes should be absent. (Ikeme, 1990) The design should be such that will ensure correct sequence of operation that encourages efficiency while discouraging contamination and cross-contamination (Igwe, 2000 and 2005). The standard sequence for conversion of animals to meat include: Lairage rest / antemortem examinations, immobilization, killing, evisceration, postmortem examination, cutting-up and storage / processing / marketing.

Good sanitation is required in abattoir practice (Ikeme, 1990).

Unlike in developing countries, these are easily achieved in developed countries. To what extent the above prescriptions have been attained in Nigeria with Kano abattoir as the case study is the major objective of this research.

MATERIALS AND METHODS Kano abattoir is located in Kano, the capital of Kano State, which is in the North Western part of Nigeria. Instruments of data collection were structured questionnaires, oral interviews, personal observations and documentary sources.

RESULTS AND DISCUSSION The various abattoir practices in Kano abattoir with critical evaluation of their compliance to standard abattoir practices are shown in Table 1. It was observed that the design of the Abattoir even though old was good but all the facilities are grounded. There was no functional pipe borne water and this gives room for contamination and cross contamination of the carcass. Lairage is available at Kano Abattoir but because it is not currently in use it has been converted to a mini parking area/retail market. This agreed with the findings of Igwe (2005) and Aliyu et al, (2008) which states that lairages are not available in most Nigerian Abattoirs and where available they are not put to use. Because of the absence or non functionality of lairages, there is hardly any ante mortem inspection in Kano Abattoir. The method of immobilizing the animals is crude as it involves physical struggle to wrestle down the animal which according to Ikeme (1990) affects the quality of the meat. Hoists are available but not functional also and this means improper draining of blood from the animal which also affects the quality of the carcass as observed by Igwe (2005).

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The evisceration of animals was normally done manually but quite professional. It was also observed that there was a fairly good post mortem inspection in Kano Abattoir but there is

still room for improvement. Other areas where Kano Abattoir recorded positive practices which are also quite professional include cutting up of the carcass and by products utilisation.

Table 1: Evaluation of Level of Compliance to Standard Practices in Kano Abattoir

S/N Abattoir activity Situation on ground Remarks 1. Slaughter facilities Good design with virtually all the facilities that

are no longer functional Political will needed to relocate to completed and functional abattoir

2. Types of Animals Cows, camels, goats and sheep. For religious reasons Pigs are not slaughtered

3. Daily Slaughter figures Cows (250 – 300), Camels (60 – 80), Goats (600 – 700) and sheep (600 – 700)

These figures varies from season to season

4. Lairage Exists, but hardly used Should be enforced 5 Ante mortem Absent Should be enforced 6. Immobilization Crude. Struggling to wrestle down the animals

with butchers often wounded. Facilities bad. and need for butchers’ education.

7. Killing Hoists not working, hence killing is done on the floor.

Improper bleeding

8. Evisceration Quite professional Should be encouraged 9. Postmortem Inadequate. Serious need for change. Public health at risk. 10. Fetal losses No records of such. Quite unprofessional 11. Cutting-up Quite professional Should be sustained. 12. Byproduct Handling Quite professional Should be sustained 13. Waste Handling and

Sanitation Fairly okay. No internal water supply properly functioning.

Repair of boreholes and supervision of sanitation.

Source: Developed from observations, visits, interviews and consultations

Table 2: Slaughter Figures and Postmortem Condemnations for Cattle for Twelve months (June, 2007 – May, 2008)

Months Total Slaughter

Total Rejects

Liver Lungs Heart Kidney Tongue / Heads

GIT

June, 07 5651 00 2 10 3 00 00 00 July, 07 5764 2 5 28 5 1 00 5 Aug, 07 6020 1 17 79 2 00 1 21 Sept, 07 6530 1 9 26 7 1 00 6 Oct, 07 7492 2 4 12 2 1 00 3 Nov, 07 7937 00 1 12 3 00 00 1 Dec, 07 6928 2 12 26 1 1 00 1 Jan, 08 6842 00 2 7 2 00 00 00 Feb, 08 6212 00 6 7 2 1 00 1 March, 08 6592 1 4 5 3 00 00 00 April, 08 6366 00 2 19 00 2 00 1 May, 08 6415 2 1 5 1 00 00 00 Total 78749

(100) 11 (0.014)

65 (0.083)

236 (0.230)

31 (0.039)

07 (0.009)

01 (0.001)

39 (0.050)

NB: Figures in parentheses are percentages of Total slaughter figures Source: Kano Abattoir

Table 3: Slaughter Figures for Camels, Sheep / Goats and Cattle for Nine months (June, 2007 –February, 2008)

Months Total Slaughter (Cattle)

Total Slaughter (Camels

Total Slaughter (Goats / Sheep)

Overall Total Slaughter

June, 07 5651 (21.56) 1535 (05.85) 19028 (72.59) 26214 (100.00) July, 07 5764 (25.15) 1253 (05.47) 15896 (69.38) 22913 (100.00) Aug, 07 6020 (25.19) 1005 (04.21) 16871 (70.60) 23896 (100.00) Sept, 07 6530 (26.73) 686 (02.81) 17218 (70.46) 24434 (100.00) Oct, 07 7492 (35.58) 962 (04.57) 12603 (59.85) 21057 (100.00) Nov, 07 7937 (45.28) 1189 (06.78) 8404 (47.94) 17530 (100.00) Dec, 07 6928 (41.17) 1088 (06.47) 8810 (52.36) 16826 (100.00) Jan, 08 6842 (39.47) 1241 (07.16) 9251 (53.37) 17334 (100.00) Feb, 08 6212 (33.48) 1216 (06.55) 11125 (59.96) 18553 (100.00) Total 59376 (31.46) 10176 (05.39) 119206 (63.15) 188758 (100.00)

NB : Figures in parenthesis are Percentages of Total Slaughter Source: Kano Abattoir, September, 2008

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Table 4: Slaughter Details and Postmortem Condemnations for Cattle, Camel and Sheep / Goats between March, 2007 and February, 2008. Slaughter Details Cattle Camels Goats / Sheep Total Slaughter 59376 10176 119206 Condemnations Total rejects 11 (0.019) 00 (0.000) 01 (0.0004) Liver 58 (0.098) 00 (0.00) 00 (0.00) Lungs 207 (0.349) 01 (0.001) 14 (0.012) Hearts 27 (0.045) 00 (0.00) 00 (0.00) Kidney 05 (0.008) 00 (0.00) 00 (0.00) GIT 38 (0.064) 00 (0.00) 14 (0.012) NB: Figures in parenthesis are Percentages of Total Slaughter. Source: Kano Abattoir, September, 2008

The slaughter figures and post mortem condemnations for cattle in Kano Abattoir for the study period were shown in Table 2. From the Table it can be seen that the total number of cattle slaughtered ranged from 5,000 to approximately 8,000 with the highest number of 7,937 in November 2007; and the least figure of 5,651 was recorded in June 2007. The highest condemnations for the study period were in lung related diseases followed by liver and Gastro intestinal tract infections. Igwe (2005) observed highest condemnations in liver related diseases followed by lungs and GIT diseases respectively. The least condemnations were in Tongue/head related diseases. Table 3 shows slaughter figures for cattle, camel and Goat/sheep for the twelve months period. It can be seen that the highest number of animals slaughtered were goats/sheep with a figure of 119,206 and this agreed with the findings of Muhammad, Rabi and Abdullahi (2007). This was followed by cattle 59,376 and camel 10,176. The highest monthly overall total slaughter figure of 26,274 was obtained in June 2007 while the least figure of 16,826 was obtained in December 2007. Slaughter details and post mortem condemnations for cattle, camel and Goat/Sheep for the 12 months period are shown in Table 4. It can also be seen from the Table that the highest condemnations were obtained in cattle, and they were lung related diseases followed by liver diseases. The cattle are followed by Goat/Sheep with equal number (14) of condemnations in lungs and GIT diseases. Camels have the least condemnations among all the animals slaughtered in Kano Abattoir.

CONCLUSIONS AND RECOMMENDATIONS

Based on the results of this study, it can be concluded that the small ruminants (Goat/Sheep) constitute the highest slaughtered animals and the Camels the least slaughtered in Kano Abattoir. It can also be concluded that there was very low post mortem condemnations which indicates slaughter of healthy animals; this is quite surprising considering the fact that ante mortem inspection and lairage rest are not enforced. Much more condemnations are observed in cattle and the least in camels among all animals slaughtered in Kano Abattoir within the study period. For both qualitative and quantitative animal protein supply to Kano public, standard Abattoir practices has to be observed and to achieve this the following recommendations are here by made: • Strict enforcement of Lairage rest and

antemortem examination would to a large extent minimize the slaughter of diseased animals

• Government should institute mandatory and compulsory fetal recovery programs.

• All facilities in the Kano Abattoir should be overhauled and up graded; at the same time ensuring strict compliance to proper sanitation.

• Public health education program on the importance of ethical abattoir practices for the abattoir personnel especially the butchers should be organized at least once a year. Similarly the general public should be made to understand the techniques of detecting diseased meat especially the organ meat.

• Most importantly, Kano State Government should invoke political will to force the movement to the new standard abattoir that was constructed and laying wasted.

REFERENCES Aliyu, J.; Ibrahim, A.A.; and Abba Aja,

H.K.(2008).The effect of livestock slaughter on foetal loss and disease incidence in Maiduguri Abattoir. Techno-Science Africana Journal 2(1):15-22.

Igwe, E. C. and Yakubu, B. (2000). Animal Slaughter Characteristics:

Implications for the future of Beef production and Peoples’ nutrition. Proc. 5th Ann. Conf. Animal Science Assoc. of Nigeria. Port Harcourt, Nigeria. September, 2000.

Igwe, E. C. (2001). Abattoir Practices in Adamawa State. Journal of Arid Agriculture.

Igwe, E. C. (2005): Adamawa State Meat Industry. In Agriculture in Adamawa State. Edited by

Igwe, E. C., S. I. Mshelia, S. I. & Jada, M. Y. Paraclete Pub. Yola. ISSBN: 978-8055-26-5

Ikeme, A. I. (1990). Meat Science and Technology: A Comprehensive approach. African FEP Publishers, Onitsha

Kano Abattoir (2008). Record of daily activities. Unpublished.

Muhammad, I.R.; Rabi, A.; and Abdullahi, A.Y.(2007).Implications of slaughter of pregnant Ewes and Does to future livestock in semi arid urban abattoir. Journal of Animal and Vet. Advances 6(6):819-822.

Obanu, Z. A. (1986). Losses and their control in the meat industry. Paper Presented at National workshop on postharvest food losses and their control. University of Nigeria, Nsukka.

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DESIGN AND DEVELOPMENT OF A FLEXIBLE RECHARGE VOUCHER GENERATOR FOR PREPAID BILLING IN GLOBAL SYSTEM FOR MOBILE COMMUNICATIONS (GSM) SYSTEMS

Ahmed Baita Garko Department of Mathematical Sciences, Kano University of Science & Technology, Wudil - Kano State

[email protected]

ABSTRACT A flexible Recharge Voucher Generator is a system developed to be generating recharge card PIN numbers for bill settlement in the prepaid billing platforms for GSM communications systems. The system is flexible in such a way that amount and length of the PIN numbers can be adjusted at each run of the program. During the research, it was discovered that some Service Providers use 12-digit PIN numbers while others use more than that on their recharge vouchers. The system was developed by simple application of Pseudo-Random Number Generator. The flexibility of the system is also extended to the recharge card sellers, where the system provides avenue for them to log on to the internet and get the next available recharge voucher without having to physically go to the source, provided the recharge card seller is registered with the GSM company, and fulfils all the necessary requirements like having deposited some substantial amount of money in his bank account that is accessible to the GSM company by signing a contract agreement between the two. By so doing, this will save the card seller money and energy in going to buy from dealers.

Keywords: Global System for Mobile Communications (GSM), Prepaid Billing Software, Pseudo-Random Number Generator, Internet.

INTRODUCTION The first generation (1G) of the mobile communication system was developed in the 1970s, and was based on analogue mode of transmission. The 1G analogue system saw two key improvements, the invention of the microprocessor and the digitization of the control link between the mobile phone and the cell site. An AMPS (Advanced Mobile Phone System) was first launched by United States, based on the analogue system. At that time, it was based on FDMA (Frequency Division Multiple Access) technology. It only allowed users to make voice calls within one country. (Sopan, 2004).

When compared to the first generation, the second generation (2G) of the mobile communication systems, used digital multiple access technology not analogue as in the case of the 1G network. The 2G networks used technologies such as TDMA (Time Division Multiple Access) and CDMA (Code Division Multiple Access). The GSM (Global System for Mobile Communications) networks used TDMA technology. The 2G digital cellular systems were first developed at the end of the 1980s. (Lawrence, 2006) The introduction of the GPRS (General Packet Radio Service) in the Mobile Communication Industry moved us to the 2.5 Generation mobile systems. The GPRS is a radio technology for GSM networks that adds packet-switching protocols, shorter set up time for ISP (Internet Service Provider) connections, and the possibility to charge by the amount of data sent, rather than connection time. (Lawrence, 2006). The 3G networks were characterized by faster communications services, including Voice, Fax and Internet, anytime and anywhere with

seamless global roaming. The first third-generation (3G) network was deployed in Japan in 2001. This happened when 2.5G networks such as GPRS (Global Packet Radio Service) are already available in some parts of Europe. The 3G technology supports 144 kbps bandwidth, with high-speed movement (e.g. vehicles), 384 kbps (e.g. on campus) and 2 mbps for stationary (e.g. building). (Lawrence, 2006). From the time a call is initiated on a GSM network up to the time it reaches the destination it is regarded as a service provision.

In which ever case, providing an avenue for one to communicate from one location (Continent, Country, State or Locality) to another is regarded as service provisioning, which would consequently attract some charges to be paid for the services delivered, by the service provider (Communication Company). The way this charges are communicated and received to and from the customers respectively is best known as Billing. There are two prominent ways of billing in GSM Systems; these are prepaid and postpaid billing platforms. More attention is paid in this paper on the prepaid, as it is currently the predominant way of billing now amongst Nigerian GSM Operators. Normally, the prepaid billing does not care to know the person making a call; rather that person has to have some certain amount of money on his or her SIM card before the call is initiated. This is literally making payment in advance before making calls on the GSM network. This advance payment is done by buying a recharge voucher from either a dealer or road side recharge card sellers, scratching off the silver cover on the card and loading the PIN numbers on the same card on to the telephone.

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In the prepaid billing system as we have seen in the definition according to Wikipedia Encyclopedia (2007), is the type of billing that involves making a payment in advance before the usage of a service.

Statement of The Problem 1- Periodic unavailability of recharge cards. 2- Putting some additional amount of the

selling price of a recharge card by some road side recharge card sellers. The aim of the research is to design and

develop a Flexible Recharge Voucher Generator that is beneficial to both the GSM subscribers and the recharge card sellers by providing an avenue to download the generated vouchers from the Service Provider’s Website without having to go physically, thereby saving time and other resources. The objective is to explore the diverse problems associated with the prepaid billing systems voucher generation and sales thereby coming up with a practical solution.

ANALYSIS OF THE PREPAID BILLING In prepaid billing the customer buys a given amount of credits (duration, volume, number of events) and is then allowed to use the corresponding network resources as long as their account is in credit. Billing system receives customer usage records from the network elements and adjusts the customer credits. When the credit has been used up, the network usage will be restricted. (Hatem, 2006).

Hatem further stated that, prepaid corresponds to a real-time process, because transactions are only allowed if the user account is in credit, and this has to be checked in real-time. According to Arjen (2001), a prepaid service is a service for which the customer pays in advance. The ability to pay in advance for services has become a global, multi-billion dollar business, used for fixed and mobile telecommunications, internet, pay TV and across other industries. Currently prepaid telecommunication services are offered by over 90% of European mobile operators. Two different perceptions can be distinguished as far as the prepaid billing is concerned.

The Service Provider Perception The postpaid principle is based on a strong relationship between provider and customer. The relationship must be able to provide the service provider with the assurance that all debts will be paid. No matter how strong the relationship is, there is always a large risk of bad debt. (Arjen, 2001). Arjen further stated that, prepaid services not only prevent the provider from handling bad debt situations, but in the current situation, they also lower the incremental strain on resources. But surprisingly, he also mentioned some words as, besides the claimed advantages, there is a downside Prepaid service offering requires real-

time or almost real-time accounting, to prevent unauthorized use. This puts some serious constraints on the system and the infrastructure used by the operator. Also he stated that, the overall risk profile is larger than with postpaid subscription based services, because of the variability revenues.

The Customer Perception Arjen (2001) discussed on the customer’s perception of the prepaid with simplicity and transparency. Especially for customers using new services, Prepaid services offer the big advantage of predictability, and prevent the customer from any surprises, when new services are being billed, and the bills are presented. But he also stated the disadvantages for the customer, are the additional effort for upgrading his account, and the loss of interest because of the early payment. According to Arjen (2001), the prepaid concepts are divided into four. One of them is:

Handset Based Concept Steps involved in prepaid call origination of a handset based system:

a- Prepaid customer initiates a call (dials number).

b- Mobile Switching Center (MSC) sends AoC (Advice of Charges) to handset. AoC is based on rate plan and various parameters (such as time and destination).

c- If the handset supports AoC, then the handset will acknowledge the receipt of the AoC parameter. If no acknowledgement is received by the MSC the connection is denied, otherwise the call is connected.

d- During the call, the handset uses the AoC parameters for tariff information. It decrements the credit on the sim card by incrementing the used units in the sim card’s Accumulated Call Meter (ACM). If the sim card determines that the ACM has reached the maximum allowed ACM threshold value, the handset disconnects the call. This AoC disconnection mechanism works automatically in the handset, without any involvement from the network.

System Design According to Stephen (1996), the aim of the design phase in software development is to determine how efficiently a product is going to operate after employing some good design tools. Starting with the specification (problem definition) document, the designer determines the internal structure of the product. Also during the design phase, algorithms are selected and data structures chosen. The inputs to and outputs from the product are laid down in the specifications, as are all other external aspects of the product. In our own case, the product is the Hybrid Billing Software.

32


This has to be decomposed into various modules, so as to ease our work. In a related topic, Williams and Sawyer (1999) called the system design phase of software development as a Detail Design Phase.

System Design Modeling Pressman (2005) suggests some kinds of Design Models in software engineering. Some of which are:

1- The Data / Class Design: This transforms analysis models into design class realizations and the requisite data structures required to implement the software.

2- The Architectural Design: This defines the relationship between the major structural elements of the software, the architectural styles and design patterns that can be used to achieve the requirements defined for the system, and the constraints that affect the way in which architectural design can be implemented, (Pressman, 2005).

3- The Interface Design: This describes how the software communicates with systems that interoperate with it, and with humans who use it, according to Pressman (2005). He further stressed that an interface implies a flow of information (e.g. data, and/or control) and a specific type of behavior. Therefore, usage scenarios and behavioral models provide much of the information required for interface design.

This transforms structural elements of the software architecture into a procedural description of software components. Information obtained from the class-based models, flow models, and behavioral models serve as the basis for component design, according to Pressman (2005). In order to achieve the goal of modeling the system design, the unified modeling language (UML) is used. The UML is a language that provides the necessary technology to support Object-Oriented Software Engineering practice.

Fig. 1: Activity Diagram for the Flexible Recharge Voucher Generator

Flexible Recharge Voucher

System Administration

Card Seller Administration

Voucher Downloads (By Card Seller)

Customer Settlements

Access Database Tables

Update the database tables

Stop Next Activity

33


Fig. 2: Activity Diagram for Customer Bill Settlement

Use-Case Diagrams for Flexible Recharge Voucher Generator Here, the use-case diagrams are for the card seller and the customer settlement administrator who generates the recharge vouchers in the billing system.

Voucher Web Portal

Log on to the Internet

Download Voucher

View A/C Balance

View Monthly Transactions

Card Seller


Read username, password

Valid

Display Main Menu

Find Voucher Status Load Voucher

Update Database Tables

Do Another Yes No Stop

No Yes

Fig 3: Use-case Diagram for Card Seller

34


Fig. 4: Use-case Diagram for Customer Settlement Administrator RESULT


Generate Voucher

Insert Voucher into DB table

Generate Report

Find Voucher Status

CS Administrator

35


Table 1.0: Showing a sample Recharge Voucher Report.

PIN Numbers Date Amount Status Seller_id

207452448384 2008-04-09 1000 Valid 1001 461520627555 2008-04-09 1000 Valid 1001 830515510787 2008-04-09 1000 Valid 1001 472150641150 2008-04-09 1000 Valid 1001 330411305372 2008-04-09 1000 Valid 1001 252331207643 2008-04-09 1000 Valid 1001 721326180865 2008-04-09 1000 Valid 1001 363761121147 2008-04-09 1000 Valid 1001 221122775368 2008-04-09 1000 Valid 1001 374300143531 2008-04-09 1000 Valid 1001 611027560853 2008-04-09 1000 Valid 1001 253562601124 2008-04-09 1000 Valid 1001 012833355346 2008-04-09 1000 Valid 1001 265002523528 2008-04-09 1000 Valid 1001 743086416741 2008-04-09 1000 Valid 1001 376531546122 2008-04-09 1000 Valid 1001 234802201344 2008-04-09 1000 Valid 1001 155713103615 2008-04-09 1000 Valid 1001 524707086837 2008-04-09 1000 Valid 1001 166242026100 2008-04-09 1000 Valid 1001 024604671322 2008-04-09 1000 Valid 1001

DISCUSSION The software was designed and developed and found to be very efficient as it yielded a very good result. The result was obtained by the simple application of Visual Basic Random Number Generator and System clock. The vouchers generated are downloaded by the card sellers thereby minimizing expenditure from the point of view of the Service Providers, for printing the cards on expensive material. The registered card sellers need not to go to the customer service center or dealer to purchase the cards in bulk; the seller can simply log on to the internet and send his request to the server, and finally downloads his vouchers without tears. The quality is also very good as there is no need to print a hard copy, the soft copy can be seen on

screen directly, eliminating any chance of making mistake as a result of printing. Above all, the PIN numbers will never be repeated provided the system time varies during generation even by one (1) second.

CONCLUSION This work presents the Methodology for the Design of a Flexible Recharge Voucher Generator, to be used by the Global System for Mobile Communications (GSM) providers for their prepaid customers and recharge card sellers. The result obtained from the development of the design are encouraging and promising for coming up with more complex software in the future.

REFERENCES Sopan T. (2004), Evolution of the Mobile

Technology, By Instant Book, USA. Lawrence H. (2006), Introduction to Mobile

Telephone Systems 2nd Edition, Instant Book, USA

Wikipedia Encyclopedia (2007), Billing in mobile communication, www.wikipedia.org

Hatem M. (2006), Introduction to Billing Systems, By Design and Strategy Articles, USA

Arjen B. (2001), Prepaid in Mobile Telecommunications, Published by

TELEMATICA INSTITUUT, http://gigaabp.telin.nl

Stephen R. S. (1996), Classical and Object-Oriented Software Engineering, McGraw Hill, USA

Williams K. B. and Sawyer S. C. (1999), Using Information Technology, A Practical Introduction to Computers and Communications (Third edition), McGraw Hill New York USA

Pressman R. S. (2005), Software Engineering A Practitioner’s Approach Sixth Edition, McGraw Hill, USA

36


DESIGN AND IMPLEMENTATION OF HYBRID BILLING SOFTWARE FOR CODE DIVISION MULTIPLE ACCESS (CDMA)

COMMUNICATION SYSTEMS

1Ahmed Baita Garko, 2Bello Idrith Tijjani 1Dept. of Mathematical Sciences, Kano Univ. of Sci. & Tech. Wudil

[email protected] 2Dept. of Mathematical Sciences, Bayero University, Kano

ABSTRACT Looking at various problems associated with the two prominent Billing Platforms (Prepaid and Postpaid) and also the nature of flow of income in the middle class of Nigerian population, the need for an alternative billing platform becomes necessary in order to solve some of the problems discovered in Prepaid and Postpaid during the research. In some developed countries there is what is called “convergent billing” where the two billing platforms are operated on the same billing system allowing the customer to choose the best option he prefers. But in Nigeria there is no such option, it was discovered that the Prepaid is mostly beneficial to the service provider in terms of collection (payments), but at the expense of the customers for not allowing them to make calls at zero credit. For the Postpaid, many errors were discovered that encourage revenue leakages and discourage customer patronage. The Hybrid Billing Software developed was the first of its kind provided as alternative for customer to make calls at zero level of credit and settle his bill at the end of the month by buying a recharge voucher, log on to the Internet view his bill and settle it by loading the recharge voucher, this is achieved by getting the call detail records from switches. By so doing, the system behaves like Postpaid as making calls with no credit is permissible, and Prepaid as bill settlement is done using the recharge voucher, contrary to Postpaid where bills are settled by cash.

Keyword: Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), Prepaid and Postpaid Billing, Call Detail Records (CDR), Software, Internet.

INTRODUCTION According to Jeffrey et al (2001), the best way to describe mobile communication systems is to call it your basic cellular phone services. The cell phone communications industry has over the years evolved along two main paths – The code division multiple Access (CDMA) path, and the Global System for Mobile Communications (GSM) path. Recently, the GPRS, that is, General Packet Radio Service was introduced to provide additional services to the mobile communication. According to Sopan (2004), the first radio telephone service was introduced in the United States (U.S) at the end of the 1940s, at that time it was meant to connect people driving in cars to the fixed network used by the public, at home or in the offices. The first generation of the mobile communication system was developed in the year 1970s, and was based on analog mode of transmission. The 1G analog system saw two key improvements, the invention of the microprocessor and the digitization of the control link between the mobile phone and the cell site. An AMPS (Advanced Mobile Phone System) was first launched by United States, based on the analog system. At that time, it was based on FDMA (Frequency Division Multiple Access) technology. It only allowed users to make voice calls within one country. (Sopan, 2004). When compared to the first generation, the second generation of the mobile communication

systems, used digital multiple access technology not analog as in the case of the 1G network. The 2G networks used technologies such as TDMA (Time Division Multiple Access) and CDMA (Code Division Multiple Access). The GSM (Global System for Mobile Communications) networks used TDMA technology. The 2G digital cellular systems were first developed at the end of the 1980s. (Lawrence, 2006) The introduction of the GPRS (General Packet Radio Service) in the Mobile Communication Industry, moved us to the 2.5 Generation mobile systems. The GPRS is a radio technology for GSM networks that adds packet-switching protocols, shorter set up time for ISP (Internet Service Provider) connections, and the possibility to charge by the amount of data sent, rather than connection time. (Lawrence, 2006). The 3G networks were characterized by faster communications services, including Voice, Fax and Internet, anytime and anywhere with seamless global roaming. The first third-generation (3G) network was deployed in Japan in 2001. This happened when 2.5G networks such as GPRS (Global Packet Radio Service) are already available in some parts of Europe. The 3G technology supports 144 kbps bandwidth, with high-speed movement (e.g. vehicles), 384 kbps (e.g. on campus) and 2 mbps for stationary (e.g. building) (Lawrence, 2006).

37


THE CODE DIVISION MULTIPLE ACCESS (CDMA) The CDMA is based on the spread spectrum technology. Since it is suitable for encrypted transmissions, it has long been used for military purposes. Transmission is spread over the whole radio band, and each voice or data calls are

assigned a unique code to differentiate from the other calls carried over the same spectrum. Also, CDMA allows for a “soft hand-off”, which means that terminals can communicate with several base stations at the same time. (Lawrence, 2004)

CDMA 2000 System 1.25MHz IS-95CDMA 1.25MHz PSTN or PTT 3.75MHz IS-95 CDMA CDMA 2000 and CDMA 2000 3.75MHz Internet CD CDMA 2000 Fig. 1: Diagram showing a typical CDMA 2000 System. Key PSTN: Public Switch Telephone Network, PTT: Push to Talk RNC: Radio Network Controller, GSN: GPRS Support Node, MSC: Mobile Switching Center How the CDMA 2000 System Operates The real operations are as follows. a- A service (Voice calls or data transmission) is

initiated by the terminal. b- The service is transmitted to the Node B. c- Various Node Bs are connected to Radio

Network Controller (RNC), and so take the calls to the nearest RNC.

d- The RNC looks for the service type: if it is a voice call, it is routed to Mobile Switching Center (MSC) else it is routed to GPRS Support Node (GSN).

STATEMENT OF THE PROBLEM For many years, even before the advent of the mobile communications in Nigeria, there were many problems associated with Nitel (Nigerian Telecommunications Ltd), which was the only telephone operator in the country. Most of the problems then were from the billing aspect of the company. The subscribers’ complaints included wrong posting of their payments, over billing and other problems associated with the connectivity. After the take-off of the mobile communications companies in Nigeria in 2001, yet subscribers are still experiencing some problems with the billing types. These and other problems associated with billing are summarized as shown below:

NODE B

NODE B

MSC

GSN

RNC

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Problems of Postpaid Billing (a) From the Customer’s point of view

1- Wrong posting of payments to the right customer’s account. 2- Over billing. 3- Wrong meter readings. 4- Accumulation of rental charges even when the line is faulty. 5- Bills dispatch problems.

(b) From the Service Provider point of view 1- Failure of the subscribers to make payment promptly. 2- Overhead cost for employing staff in the customer care centre. 3- Cost of buying stationeries for bill printing. 4- Cost for bills distribution. 5- Open to fraud by the company’s staff. Problems of the Prepaid Billing

1. Periodic unavailability of recharge cards. 2. Impossibility of making a call at zero level of credit. 3. Putting some additional amount of the selling price of a recharge card by some business

center operators. 4. Some areas even though there is a network, you hardly see a recharge card seller.

The aim of the research is to design a hybrid billing software, that would minimize the problems inherited from the postpaid and prepaid billing platforms, and would be operating by combining the good aspect of the two platforms. The objective is to explore the diverse problems associated to the postpaid and prepaid billing systems and come up with the practical solution in the hybrid billing system.

METHODOLOGY According to (HIGHDEAL, 2007), the benefit of combining some attributes of prepaid and postpaid billing system is that, it will support a common set of services and tariffs and allow customers to choose which payment method they prefer at different times. HIGHDEAL continues, mobile operators should consider providing alternative payment methods for their customers. These days, online shoppers can purchase products and services irrespective of time and place.

Analysis of the Postpaid System The procedure can be shown diagrammatically as: Figure 2: Diagram showing the Postpaid Billing Procedure

Cash

Network Clearinghouses, other Billers

Customer Care Postpaid

Billing System

Post Billing

History

Invoice

39


From the postpaid procedure diagram shown above, the following shortcomings were noted: 1. There is too much paper work involved, which will consequently cost the telecommunication

company. 2. Fraud would be prevalent as too many people are involved in the process. 3. Efficiency would also be less, as some personnel may introduce unnecessary delay. 4. Payment made by the customer may be delayed before capturing in the billing system; this is due

to following long protocol. 5. Payments might be captured wrongly. For example, by typing wrong account number, since it is

not the customer who is crediting his account directly 6. Whenever there is fault in the subscribers’ line, it takes longer time than necessary before his

problem is solved due to corruption. 7. Considering the procedure, definitely, there is a lot of revenue leakages from inception to the bill

distribution. Therefore, there is no revenue assurance in the system 8. There is always a problem when it comes to reconciliation between the customer service center

and billing department, for the payments made by the subscribers 9. Delay in bills distribution, as customers are served with their bills by dispatch riders.

ANALYSIS OF THE PREPAID BILLING The procedure involved in prepaid billing is not lengthy; it can be shown as follows: 3 3 1 2 3 4

Fig. 3: The Prepaid Billing System 5 Key: Solid Line: Voice Trunk, Dashed Lines: Singling, AUC: Authentication Center, HLR: Home Location Register, MSC: Mobile Switching Centre, PSC: Prepaid Service Centre, SSP: Service Switching Point

Shortcomings that are peculiar to the prepaid billing in Nigerian context were uncovered. Among these problems are:

1. Unavailability of the recharge voucher at times.

2. Even if there is availability, at times some recharge vouchers for lower denominations (like N 200 and ₦100) are scarce.

3. The habit of increasing the selling price of a unit recharge voucher by the sellers.

4. Sometimes it is very difficult to load a recharge voucher due to network congestion.

5. Inability to make a call at zero level of credit no matter how urgent and important the call is.

6. Someone has to trek a long distance each time he or she wants to buy a recharge voucher.

7. The quality of some recharge vouchers is also questionable. Sometimes some numbers are removed mistakenly when trying to remove the silver cover on the

numbers (PIN numbers). This is due to poor quality of recharge card production.

SYSTEM DESIGN Stephen (1996) stressed that, starting with the specification (problem definition) document, the designer determines the internal structure of the product. Also during the design phase, algorithms are selected and data structures chosen. The inputs to and outputs from the product are laid down in the specifications, as are all other external aspects of the product. In this case, the product is the Hybrid Billing Software. This has to be decomposed into various modules, so as to ease our work. In a related topic, Williams and Sawyer (1999) called the system design phase of software development as a Detail Design Phase.

Design of a Hybrid Billing Software We have seen that a billing system is a very complex system. So combining the characteristics of the prepaid and postpaid billing systems would make the Hybrid Billing system more complex.

MSC SSP

HLR AUC

PSC

40


In order to reduce this complexity, we followed the suggestion made by Pressman (2005) that the design should be modular. Hence, our Hybrid Billing Software is broken down into various independent modules that are communicating from time to time to realize a common goal. That

is, the way customers enjoy services offered in a mobile communication company, and settle their bills in a way and manner operated in both the prepaid and postpaid environments.

The Hybrid Billing Software is represented together with its components as follows:

Fig. 4: Diagram showing the interaction of the proposed hybrid system components SYSTEM DESIGN MODELING In order to achieve our goal of modeling the system design, the unified modeling language

(UML) is employed. The UML is a language that provides the necessary technology to support Object-Oriented Software Engineering practice.

Customer Settlement

Database Tables

Billing Admin /Ops

System/Database Administration

Management Reporting

Customer Administration

41


RESULT

Fig. 1.6 Diagram showing some results from the new Hybrid Billing System

42


Fig. 1.5 Activity Diagram for the entire Hybrid Billing System

Hybrid Billing Software

System Administration

Customer Administration


Operator

Customer Loading a Recharge Voucher

Billing Administration

Management Reporting

Again? Yes No Stop

43


DISCUSSION The software was designed and implemented and found to be very efficient as it yielded a very good result. The reports eliminated the paper work thereby minimizing expenditure from the point of view of the Service Providers. The customer needs not to go to the customer service center to collect his bill; he can simply log on to the internet and view his bill. The quality is also very good as there is no need to print a hard copy, the soft copy can be seen on screen directly, eliminating any chance of making mistake as a result of printing. Another important aspect of the Hybrid Billing Software is providing the customer with access to personal account; customer can effectively manage his account.

CONCLUSION This paper presents the Methodology for the Design of Hybrid Billing Software for Code Division Multiple Access (CDMA) Communication Systems. The result obtained from the implementation of the design are encouraging and promising for development of more complex software in the future. The two main billing platforms in mobile communications systems can be studied, analyzed and improved upon to come up with a complex system. I believe it can further be improved upon one day to produce another product that is much more beneficial to the teaming customers and the mobile communications companies.

REFERENCES Jeffrey W., Randy H., Jackie T., Alicia N., and Andy

M. (2001), Designing a Wireless Network, By Syngress Publishing USA

Sopan T. (2004), Evolution of the Mobile Technology, By Instant Book, USA.

Lawrence H. (2006), Introduction to Mobile Telephone Systems 2nd Edition, Instant Book, USA

Lawrence H. (2004), Introduction to CDMA Network, Services, Technologies, and Operation, Instant Book, USA

HIGHDEAL (2007), Defining the Context of Convergent Billing,

www.Highdeal.com/product/billing-EN.shtml

Stephen R. S. (1996), Classical and Object-Oriented Software Engineering, McGraw Hill, USA

Williams K. B. and Sawyer S. C. (1999), Using Information Technology, A Practical Introduction to Computers and Communications (Third edition), McGraw Hill New York USA

Pressman R. S. (2005), Software Engineering A Practitioner’s Approach Sixth Edition, McGraw Hill, New York USA

44


METHYLENE BRIDGED QUINOLINE FUNCTIONALISED IR(I) NHC COMPLEXES AS EFFICIENT CATALYST IN HYDROGEN TRANSFER

REDUCTION REACTIONS

Aminu, A. Department of Chemistry, Kano University of Science and Technology Wudil, P.M B. 3244, Kano

Nigeria. E-mail- [email protected], 07061862620.

ABSTRACT Two quinoline based Ir(I) NHC carbene complexes were tested for their catalytic activity in homogenous transfer hydrogenation of 4-bromoacetophenone to 1-phenylethanol both giving over 90% conversion after 180 minutes. Isopropyl alcohol (iPrOH) was used as a hydrogen source and potassium terbutoxide ( tBuOK )as a base promoter. The catalyst were prepared by transmetallation of their corresponding silver(I) NHC complexes with [Ir(cod)Cl]

2 in DCM.

Key words: transfer hydrogenation, NHC, TON INTRODUCTION The use of phosphine ligands (PR

3) is well known

in organometallic chemistry and homogenous catalysis. N-heterocyclic carbenes (NHC) are now considered phosphine alternative for homogenous catalysis [Miecznikowski and Crabtree, 2004]. N-heterocyclic carbenes (NHCs) have attracted much attention because their transition metal complexes display rich coordination chemistry and have wide applicability in catalysis [Herrmann, 2002]. Recently research efforts have been devoted to the synthesis of polydentate ligands containing NHC moieties. The combination of pyridine and NHC functionalities leads to diverse polydentate ligands, some of which have shown interesting coordination chemistry, efficient catalytic applications and biological activities [Danopoulos et al, 2002 and Danopoulos etal, 2003]. Although the catalytic reactions take place at the metal atom, the supporting ligands bound to the metal are important for promoting and modifying catalytic activity through the prevention of metal aggregation, stabilisation of intermediates, provision of vacant coordination sites at the metal via dissociation equilibria, and modification of the steric and electronic environment about the metal ion [Cornils and Herrmann, 1996].

The basis of this study is to develop new ligand structure, by substituting pyridine with quinoline substituents, which are expected to provide greater rigidity and hence stability, though these rigid structures also lead to significant steric over crowding. Hopefully, this controlled flexibility/steric crowding parameters will lead to improved catalytic performance in a range of reactions. The catalysis presented in this work involves the use quinoline functionalised iridium (I) carbene complexes in transfer hydrogenation.

MATERIAL AND METHODS All reactions were performed under the atmosphere of dry dinitrogen or argon using standard Schlenk techniques, and solvents were

purified and dried by standard procedure, unless otherwise indicated. All other reagents were used as received. All NMR data are quoted δ/ppm. 1H and 13C (proton decoupled) spectra NMR were recorded on a Bruker DPX Advance 400 ( 1H at 400MHz,) at ambient temperature, unless otherwise stated, and referenced to SiMe

4.

PROCEDURE Transfer hydrogenation The iridium catalyst precursor was dissolved in a solution of potassium terbutoxide (KtBuO) (1 mmol) , and 2-propanol,4-bromoacetophenone (1 mmol) was added into the Schlenk tube. The solution heated to 353K for 24 hours, volatiles were evaporated and the percentage conversion was calculated by 1H NMR. The progress of the reaction was monitored by GC-MS analysis in order to calculate the time dependence of the transfer hydrogenation of 4-bromoacetophenone. Aliquots of 0.1 mL were taken every 10 minutes for the first 1 hour and every 30 minutes for the subsequent hours. The samples were filtered through a short pad of silica, and the silica was washed with DCM and analysed by GC-MS. Results and discussions The conventional methods for the hydrogenation of unsaturated bonds have involved the use of molecular hydrogen which has its draw backs due to the difficult handling procedures involved with working at high pressures. Efforts have since been devoted to developing safer, and cost effective methods, thus transfer hydrogenation represents an ideal alternative.

Rh and Ir are known to be effective catalysts for the transfer hydrogenation of unsaturated substrate by hydrogen donors (e.g. cyclohexene or 2-propanol) [Cavell and Normand, 2008]. Significantly, transfer hydrogenation of carbonyl compounds in isopropyl alcohol (iPrOH) is the most widely used reaction to test the catalytic properties of Rh and Ir because of its simplicity.

45


The catalytic transfer hydrogenation was examined using 2-propanol as the hydrogen source with a KOtBu base promoter.

Br

O

Br

OHO

catalyst, 10% base

IPA (5mL); 80oC+

Scheme 1: Catalytic hydrogen transfer of 4-bromoacetophenone

Two quinoline based iridium (I) carbene complexes prepared by transmetallation of their silver (I) carbene complexes with [Ir(cod)Cl]

2 in DCM were used as catalyst in hydrogen transfer of 4-

bromoacetophenone:

N

N NMe

Ir ClN N

N N

Ir Cl

A B

The activity of iridium complexes A and B was tested at different concentrations which enabled a direct comparison between the effects of the alkyl and the quinoline on the N-substituents. The results of the catalytic tests are presented in table 1 below. Table 1: Catalysis with A and B in hydrogen transfer reaction Entry Catalyst Concentration

(mole %) Conversion (%)

TON

1 A 1.00 99 99 2 A 0.10 99 990 3 A 0.01 65 6500 4 B 1.00 99 99 5 B 0.10 99 990 6 B 0.01 78 7800

Conditions: substrate: 1.00 mmol; KOtBu: 1.00 mmol; 353K; 24hr. Determined by NMR. As presented in the table above, both

catalysts showed good catalytic activity towards transfer hydrogenation with no significant change when the catalyst loading was reduced from 1 mole % to 0.10 mole %. When 0.01 mole % of the catalysts was used, the catalysts still showed good activity with virtually no difference

In order to evaluate the differences between catalysts A and B carbene complexes, the experiment was repeated with low catalyst loading (0.01 mol %) at 353K. The yield for the transfer hydrogenation of 4-bromoacetophenone was studied over a period of 3 hours by taking

and running the samples in GCMS after a given time and the results are presented in Figure 1 below.

As shown in the diagram below, there is no significant difference between catalysts A and B as both catalysts appeared to be highly efficient in the transfer hydrogenation of 4-bromoacetophenone to 1-phenylethanol both giving over 90% conversion after 180 minutes. The performances of the iridium carbene complexes are comparable to the pyridinyl Ir(I) NHC carbene reported by [ Peris et al, 2005].

46


0 20 40 60 80 100 120 140 160 180 20010

20

30

40

50

60

70

80

90

100Y

ield

(%)

Tim e in M inutes

C at 4 .27 C at 4 .33

Figure 1: Time dependence of the catalytic transfer hydrogenation of 4-bromoacetophenone; 0.01 mol % of cat. (A and B), KOtBu ( 10 mol%), 10 mol% of 4-bromoacetophenone, solvent 2-propanol ( 5mL), T = 353K

The steric properties of the carbene may have played important roles in the selectivity and reactivity of the systems. B is significantly more sterically hindered than the A analogue because of the presence of the bulky quinoline moiety. However this steric difference does not seem to influence the activity of the catalyst. It is envisaged that the ligand underwent partial chelation with the metal during the catalysis as

the complexes used may only be the precursors of the catalysts.

CONCLUSIONS The two quinoline based Ir(I) NHC Complexes tested in transfer hydrogenation reactions showed good catalytic activity even at low catalyst loading. The steric bulk of the ligand does not affect the catalyst performances of the catalysts as they virtually showed similar activity.

REFRENCES Cavell K.J. and Normand A. T. (2008). Donor –

functionalised N-Heterocyclic carbene complexes of Group 9 and 10 Metals in catalysis: Trends and Directions. Eur.J. Inorg. Chem. 2781-2800.

Cornils B. and Herrmann W. A. Herrmann (1996) Eds. Applied homogeneous catalysis with Organometallics compounds: A comprehensive textbook in two volumes; VCH: Weinheim.

Danopoulos A. A., Winstone S. and Motherwell W. B. (2002). Stable N-functionalised pincer’ bis carbene ligands and their ruthenium complexes; synthesis and catalytic studies. Chem. Commun. 1376-1377.

Danopoulos A. A., Winstone S. Tulloch A. D. A. Eastham G. and Hursthouse M. B.(2003). Functionalised and chelate heterocyclic carbene complexes of palladium;

synthesis and structural studies. Dalton Trans, 699- 709.

Herrmann W. A.(2002). N-heterocyclic carbenes: A new concept in organometallic catalysis. Angew. Chem. Int. Ed., 41, 1290-1309.

Miecznikowski J. R. and Crabtree R.H.( 2004). Transfer hydrogenation reduction of ketones, aldehydes and imines using chelated iridium (III) N-heterocyclic bis-carbene complexes. Polyhedron 23, 2857-2872.

Peris E., Mas-Marza E. and Sanau M. (2005). Coordination versatility of pyridine-functionalised N-heterocyclic carbenes: A detailed study of the different activation procedures. Characterization of Rh and Ir compounds and study of their catalytic activity. Inorg. Chem. 44, 9961-9967.

47


N4O

3 SCHFF BASE LIGAND IN THE SYNTHESIS OF

MULTIMETALLIC ZINC LANTHANUM COMPLEX

Abdullahi Mustapha Department of Chemistry, Kano University of Science and Technology, Wudil. PMB 3244 Kano State ,

Nigeria, Email: [email protected]

ABSTRACT The synthesis and characterisation of schiff base has been carried out. The metal to ligand ratio was found to be 3:2, while zinc metal was found to sit deep inside the pocket of the tripodal ligand, the lanthanum ion bridge between the peripheral oxygen of the tripod to form a trimetallic metal complex.

Key words: zinc, lanthanum, heptadentate, trimetallic. INTRODUCTION Recently we have develop interest in designing a multidentate ligand, which is capable of encapsulating metal ion into its pocket, and allow the complexation of second metal at the peripheral of the complex. Through this system a bi and trimetallic complexes have been generated (Abdullahi et al 2008). The potentially

heptadentate ligand with N4O3 potential donors was synthesised, while the metal complexes of Ni and Zn were reported, with the ligand coordinated to the metals in octahedral fashion. The homotrinuclear metal complexes were isostructural (figure 1) with the linear angle between the three metals found to be 175o .

Figure 1: The diagram representation of [(TtrenSalNi)

2Ni] complex

Over the years there has been a developing interest in the preparation of mixed d/f metal complexes, due to their relevance in single molecule magnet (SMM), and as contrast agents for magnetic resonance imaging (MRI) (Bayly et al., 2003 ). Due to hydrolysis problem (Malek et al 1979) there has been a limited report on the schiff base chemistry of lanthanides and mixed metallic system. However, until recently when kobayashi (2006) reported the sythesis of mixed metal system with schiff base containing Ni/Fe and Ni/Mn.

Our aim is to design a system that coagregate 3f0 and 3d10 metal ions (lanthanum and zinc). This will allow us to study their coordination chemistry and to look in to their potential application in chemoluminiscene.

MATERIALS AND METHODS All chemicals were used as purchased without further purification. The microanalysis, mass spectra and infrared spectroscopy were run at university of Strathclyde (UK). Briefly, the ligand was prepared by refluxing one mole of triethylamine with three mole of salicylaldehyde in methanol for one hour. The resulting yellow powder was obtained, filtered and dried.

Complex preparation: 1mole of the ligand (TrenSal = Tris (2-hydroxybenzylaminoethyl)amine) was dissolve in 50ml absolute ethanol, followed by the addition of 1mole equivalent of ZnCl

2. To the mixture was

added slowly 0.5mole equivalent La(NO3)3.6H

2O.

The resulting cloudy mixture was brought to reflux for 0.5 hours, after which the solution was allowed to cool and the light yellow solid filtered and dried under vacuum. Yield 65%. Infra red spectrum FTIR [ν/cm-1(KBr)]:3426 (broad, OH); 1639 (strong, -C=N); 768 (aromatic); 1152 (C-O); 1460 (NO

3). Mass Spectral analysis (ESI)

m/z, 1174 (20%, [(LZn)2La]+, 1045 (15%, [(LZn)

2]2-,

521 (90% [LZn]+). Elemental analysis, % calculated for C

55H

58N

9O

10Zn

2La: C; 51.33, H; 5.48, N; 9.79. %

found, C; 51.99, H; 5.06, N; 10.12. RESULTS AND DISCUSSION In our recent report (Abdullahi et al., 2009), we have highlighted the use of hydrogenated schiffbase in the synthesis of d and f metal complexes. The system reported there is simple and rely on the stepwise coagregation of the two metals in a systematic way.

48


The first metal coordinate by sitting in the ligand tripod while the second metal (lanthanum) coordinates to the three oxygen from each of the two primary metal complex (as in figure 1). The compound reported here [(TrenSalZn)

2La]+ is synthesised by employing similar method.

Figure 2: The proposed structure of [(TtrenSalZn)

2La]complex

Although in our last report we were able to obtain a crystal structure for the synthesised compounds, this time around we rely on the spectroscopic results to propose the structure of the compound (figure 2). The mass spectra and microanalysis (elemental analysis), together with the infrared spectroscopy were used in proposing the structure of the complex. The infrared spectra observed for this complex is typical for the family of these complexes. The imine bond (C=N) is observed at 1640 cm-1as against the previously (Abdullahi et al., 2008) reported [(TrenSal)

2Ni

3] which appear at 1635 cm-1, the C=C

aromatic was found at 1460cm-1 against 1465cm-

1, while the C-O absorption band appears at 1380cm-1 as against 1305cm-1. The shift in the C-O could be attributed to the introduction of an atom with considerably larger atomic radius than nickel, it could also be due to the higher mass of the introduced lanthanum in the core of the trimetallic arrangement (c.f. figure 1). The appearance of a strong absorption band at 1470cm-1 indicate the presence of NO

3

-, which is believed to be counter ion due to the overall positive charge on the complex ([Zn

2(TrenSal)La]+).

The structure is proposed based on the spectroscopic data (figure 2) as having two zinc metals fully encapsulated within the schiff base N3O3 donor atoms in an almost octahedral environment, two units of this molecule which serve as monoanionic is bridged by the lanthanum ion. However, the central lanthanum ion can be described as being effectively coordinated to two facially capping units of tripodal ligands in an O6 octahedral motif, with an additional coordinated solvent (methanol) forming a hepta-coordinate environment within the core. The formed trimetallic motif is not an unusual with imine schiffbase ligands, as both ohta et al and ourselves (Ohta et al 2001 and Abdullahi et al 2008) reported homotrinuclear nickel complex. The new mixed d/f complex reported here is the first for the N4O3 schiffbase ligand.

CONCLUSION The synthesis and partially characterisation of a new [Zn

2(TrenSal)La]NO

3 complex has been

carried out. However, currently a research is on the process for the synthesis of other metal systems in which obtaining a crystal will be given much emphasis, this will be used in determining the actual crystal data for these complexes.

REFERENCES Abdullahi Mustapha, Krystoff Busch, Marta

Patykiewicz, Alistair Apedaile, John Reglinski, Alan R. Kennedy, Timothy J. Prior, (2008), Multidentate ligands for the synthesis of multi-metallic complexes Polyhedron, Volume 27, Issue 2, Pages 868-878

Abdullahi Mustapha, John Reglinski, Alan R. Kennedy, (2009) The use of hydrogenated Schiff base ligands in the synthesis of multi-metallic compounds. Inorganica Chimica Acta 362 1267–1274

Ohta, H., Harada, K., Irie K, Kashino,. Kambe, T. S, Sakane G., Shibahara, T., Takamizawa, S., Mori, W., Nonoyama, M., Hirotsu, M., Kojima, M. (2001) Chemistry Letters 842.

Kobayashi, T., Yamaguchi, T., Ohta, H., Sunatsuki, Y., Kojima, M., Re, M.

Nonoyama, N. Matsumoto N., (2006), Ferro- and antiferromagnetic interactions in face-sharing trioctahedral NiIIMnIINiII and NiIIFeIIINiII complexes with the same 1–5/2–1 spin system, Chemical Communi-cation, 1050.

Bayly, S.R., Xu, Z.Q., Patrick, B.O., Rettig, S.J., Pink, M., Thompson, R.C., Orvig, C., (2003), dlf Complexes with Uniform Coordination Geometry: Structural and Magnetic Properties of an LnNi2 Core Supported by a Heptadentate Amine Phenol Ligand, Inorganic Chemistry, 42, 1576.

Malek, A., Dey, G.C., Nasreen, A., Chowdhury, T.A., (1979), Potentially Heptadentate Ligands Derived from Tris(2-aminoethyl)amine(tren), Synthesis and Reactions of Inorganic Metal Organic Chemistry, 2, 145.

49


AEROBIC REACTION OF METHANOL OVER AU/SIO2 CATALYSTS

Abdullahi Nuhu

Kano State University of Science and Technology, Wudil, P. M.B 3244, Kano State, Nigeria E-mail:[email protected]

ABSTRACT The adsorption and aerobic reaction of methanol over Au/SiO

2 catalysts were investigated. The

catalysts were prepared by incipient wetness impregnation method and tested using Pulse Flow reactor for methanol aerobic and anaerobic and` then characterized by TPPFR and TPD. The adsorption of methanol on SiO

2 shows about a half monolayer, with much of it in a dissociative

manner, forming methoxy group on the cationic site and hydroxyl group at the anions. The methoxy is relatively stable until about 250oC, at which point dehydration to dimethyl ether (DME) occurs by bimolecular surface reaction. However, the presence of gold does not change the mechanism; the products are CO

2, H

2O, CO, CH

4 and DME.

Keywords: Au catalysis, methanol oxidation, methanol catalytic combustion, TPD and TPPFR. INTRODUCTION The adsorption, reactivity, and decomposition of methanol have been studied over many metals and mixed metal oxides (Collins et al.2005). Number of mechanisms have been identified or proposed which are responsible for methanol adsorption and decomposition on metal oxides. Several other products have been reported in the literature for methanol oxidation over metal oxides (Sviatoslav et al. 2003) and none reported on the aerobic reaction of methanol over Au/SiO

2

catalyst. MATERIALS AND METHODS Catalyst preparation The catalysts used in this study were prepared by incipient wetness impregnation method (Bowker et al.2003), (James, 2002) and (Soarers et al. 2003). The pores of silica (SiO

2 (treated in air at

500oC for 2h) were impregnated with a suitable volume of an aqueous solution of HAuCl

4 (0.705

ml/gcat in this case) until incipient wetness was achieved. The sample was dried in air for two hours and ground using a pestle and mortar. The catalyst sample was passed in to a disc, crushed and then sieved between 850µm and 600µm particle aggregate size.

Methanol oxidation The reactivity of the catalyst was tested using a pulse flow reactor, which has been described in detail elsewhere (Bowker et al.2003), (James, 2002) and (Soarers et al. 2003) and (Nuhu et al. 2007). 0.5g of the pressed catalyst was held vertically in a U- tube within the oven of the reactor. 10% O

2/He gas was flowed at a rate of 30

ml per minutes. Methanol was injected periodically (2 minutes intervals) in to the gas stream. At the beginning, the gas stream passed through the bypass until the mass spectrometer signal had settled. The gas stream was then switched to over the catalyst and the products of methanol oxidation were observed using a quadrupole mass spectrometer.

Activity measurements were carried out using a Pulse Flow Reactor (PFR). The Pulse Flow Reactor was designed and constructed in house. For example, the reactor has been used by the

past group members for CO oxidation over gold nanoparticles on a TiO

2 support, propene

oxidation and ammoxidation, and it has also been used for NO

x reduction and storage

catalysts (Nuhu et al. 2007), (Bowker et al.2003), (James, 2002 and 2003 ) and (Soarers et al. 2003).

The reactor is similar to the conversional tap reactor, and it provides good kinetic and mechanistic data for catalytic reactions and allows us to test the catalyst for commercial and industrial importance.

Figure 1 shows the schematic diagram of the pulse flow reactor used in this research. The micro pulse flow reactor consist of a Philips PU 4500 GC oven which can be held at constant temperature or regulated at ramp between two temperatures at a specified rate. The oven consist of a stainless steel U tube (1/4” outside diameter, 0.065” thickness) held vertically containing catalyst (usually 0.5g) between the quartz wool. Two gases can pass over the catalyst bed, for example, helium, the carrier gas and O

2 (dosing gas) can mix over the catalyst bed

by a means of T-piece. The two mixed gases can also react with other gases, such as CO by means of a pulsing valve, which is controlled by computer and allows the user to set the time of pulsing of the gas. However, liquids such as alcohols can mix with two gases if injected via septum periodically or continuously through Razel A-99 motorised syringe pump.

BOC Ltd supplies the gases used by the reactor with a purity of 99.5% and these gases were allowed to pass through Puritubes supplied by Phase Separation Ltd, which are filled with 5 Å molecular sieves, which allows removal of water and CO

2. The flow of the gases were controlled

by mass flow controllers (Brookes 5850TR) which allows flow rate of the gases to flow within 0.1cm3 min-1 and are usually calibrated using the bubble flow meter. When the gases are mixed and reacted over the catalyst, the products flow down through the capillary tube (usually heated and depends on the type of experiment) which is controlled by a needle valve.

50


A Leybold Heraeus Trivac rotary pump mostly vents the gases flown into the capillary tube, allowing a small fraction of it to pass through a UHV chamber containing the mass spectrometer (figure 2-5) and supported by high vacuum chamber pumped with the help of Leybold 151 turbo molecular pump assisted by an Edward 5 rotary pump. The output of the reaction is monitored by computer controlled Quadrupole HAL 201 mass spectrometer constructed by Hiden Analytical and allows the results to be displayed on the computer. The thermocouple inserted in the catalyst bed allows also measuring the temperature accurately and displaying on the computer. Nevertheless, the bypass injections or pulsing allows understanding the cracking patterns of the reactants or the 100% signal of unreacted / converted of the reactants.

RESULTS AND DISCUSSION Temperature programmed reaction The oxidation of methanol was carried out over a 1wt%Au/SiO

2 catalyst, prepared by incipient

wetness impregnation. However, to understand the role of Au on methanol oxidation over this catalyst, SiO

2 was used alone as a catalyst. The

Temperature Pulse Flow Reaction result was as shown in figure (2). Figure (2) shows the saturation of methanol at room temperature (the appearance of mass 31 and 29 amu at 30 minutes). Nevertheless, between 45 and 55 minutes there is desorption of methanol, while at the beginning of 70 minutes is the emergence of dimethyl ether (appearance of mass 45 amu signal) and at 90 minutes is the appearance of CO due to dehydrogenation. The oxidation of methanol over SiO

2 is complete oxidation as evidenced by the

appearance of CO2 and H

2O

When the data was integrated and analysed, figure (3) was obtained. At a conversion of methanol of 50%, the catalyst was selective to CO

2 with selectivity being 65% and

the temperature 225oC. However, when the temperature was increased to about 350oC, the activity of the catalyst was still towards CO

2 with

selectivity value being 90% and less CO selectivity was observed, with selectivity value being 10%. The dimethyl ether selectivity is minimal and the maximum conversion of methanol was only 90%.

The 1wt% Au/SiO2 catalyst was first

calcined in-situ in 10%O2/He gas flow at a

temperature of 400oC for 30 minutes, then cooled in the gas, and then temperature- programmed reaction with methanol was carried out, as shown in figure 4. The figure 4 shows five pulses of methanol which by pass the catalyst, and this can give an idea of the cracking pattern observed for methanol. When the surface was saturated (at approximately 35 minutes) only methanol molecules broke through and no conversion of the methanol occurred. The peaks

were much smaller than those passing through the bypass, but they were also broader, due to diffusive broadening through the bed, and the integrals were similar to those through the bypass. The methanol uptake was about 20 ml corresponding to molecules 6.022X1020 molecules g-1. This corresponding with about half monolayer, Integrals were similar to those through the bypass.

The selectivity and conversion graph of methanol oxidation over a 1wt% Au/SiO

2 catalyst

(figure 5) was similar to the result of SiO2 alone.

When the conversion of methanol was 80%, the catalyst activity was selective towards CO

2, with

selectivity value being 75% and the temperature was 200oC. However, when the temperature was increased to 250oC, the methanol conversion was 95% and the selectivity of CO

2 drops to 65% and

more dimethyl ether was observed, with selectivity less than 5% and simultaneously, the CO selectivity was 22% and as the temperature increases to 350oC, the dimethyl ether decomposition begins and the CO selectivity drops to 20% and the methanol conversion was 100%.

TPD The TPD carried out over Au/SiO

2 figure 6 also

indicates that molecular methanol was desorbed at a lower temperature with desorption peaks at 69oC, lower than the temperature when SiO

2 was

used alone. Therefore, this has confirmed to us that, the presence of Au lowers the activation energy of the methanol desorption, although the difference was not much significant.

XRD The powder X-ray diffraction (XRD) pattern for a sample of SiO

2 and 1wt% Au/SiO

2 calcined and

uncalcined catalyst is shown in figure 7. The figure shows that the broad halo pattern at around 2θ equal to 23o confirms the presence of amorphous silica. Sharp crystalline peaks are noticed at 2θ equal to 38o and 44o. These reflections may be assigned to plane of cubic gold. Thus, the XRD pattern indicates that a cubic gold silica nano composition can be readily formed by incipient wetness of impregnation. It also shows that the addition of gold to SiO

2

significantly modify the support.

SEM Figure 8 shows the SEM images for SiO

2 (a) 1wt%

Au/SiO2 uncalcined (b) and calcined 1wt% Au/SiO

2

(c) prepared by incipient wetness of impregnation and dried at 120 and 400oC for 2h respectively. The figure shows the uncalcined 1wt% Au/SiO

2

catalyst (b) shows a morphology (porous irregular gold particles of varying sizes < 1.5µm to approximately 2.9µm). While the morphology exhibited by calcined catalyst1wt% Au/SiO

2 forms

similar porous irregular gold particles of varying sizes <2.6µm to approximately 2.8µm.

51


XPS The XPS spectrum of 1wt% Au/SiO

2 catalysts

(figure 9) prepared by incipient wetness shows Au 4f envelope are situated around 85 eV. These features confirmed the existence of gold in the oxidation as Aux+ for both calcined and uncalcined catalyst of 1wt% Au/SiO

2, similar to

1wt% Au/ γ-Al2O

3. However, from the XPS data it

indicates that the elemental compositions of the catalyst consist of silicon, oxygen and gold, with gold level within the expected nominal loadings (Table 1).

EDAX The data shown in table 2 shows the EDAX result obtained on 1wt%Au/SiO

2 catalyst. The main

elemental composition of the bulk of the EDAX result shows that the 1wt% Au/SiO

2 catalyst

contained C, O, Al, Si and Ti, with weight of %26.0%, 52.2%, 0.6%, 21.0% and 0.2% respectively. While the spot analysis shows that the catalyst contained O, Al, Si, Ti, and Au, with 57.6%, 0.7%, 41.0%, 0.2% and 0.7% being the weight % of O, Al, Si, Ti, and Au respectively.

He

10%O2/He

NO

Molecularsieve

Pressuregauge

Mass flowcontroller

Valve open

Valve closed

Air

Oven controller

Oven

By-passloop

CatalystU-tube

Thermocouple

Temperaturedisplay

Needlevalve

Massspectrometer

Vent

Turbopump

Rotarypump

Pneumaticvalve

controller

PTFEseptum

Vent

PulsingLoop

CPU

CPU

Figure 1: Schematic diagram of pulse flow reactor

0 10 20 30 40 50 60 70 80 90

0.0

5.0x10-8

1.0x10-7

1.5x10-7

mass 15 a.m.u.

mass 45 a.m.u.

mass 29 a.m.u.

mass 31 a.m.u.

mass 2 a.m.u.

mass 18 a.m.u.

mass 32 a.m.u.

mass 44 a.m.u.

mass 28 a.m.u.

Mas

s S

pec

Res

pons

e (A

rb. U

nits

)

Time(min)

0

50

100

150

200

250

300

350

400

Temperature oC

Figure (2): Temperature Programmed Pulse Flow Reaction for methanol oxidation over a SiO

2

catalyst

52


200 250 300 3500

10

20

30

40

50

60

70

80

90

100

Temperature (OC)

selectivity to CO selectivity to CO

2

selectivity to CH4

Selectivity to CH3OCH

3

Conversion(%)

Con

vers

ion

(%)

Sel

ectiv

ity (%

)

0

10

20

30

40

50

60

70

80

90

100

Figure (3): Selectivity and conversion with temperature for (aerobic) methanol oxidation over a SiO

2 sample

0 10 20 30 40 5 0 60 70 80 90

0.0

5 .0x10 -8

1.0x10 -7

Mas

s S

pec

Res

pons

e (A

rb. U

nits

)

T im e(m in)

0

50

10 0

15 0

20 0

25 0

30 0

35 0

40 0

m ass 16 am u

m ass 15 am u

m ass 45 am u

m ass 29 am u

m ass 31 am u

m ass 2 am u

m ass 18 am u

m ass 32 am u

m ass 28 am u

m ass 44 am u

T em pera ture oC

Figure (4): Temperature Programmed Pulse Flow Reaction for methanol aerobic reaction over 1wt%Au/ SiO

2 catalyst

53


200 250 300 3500

20

40

60

80

100

Selectivity of CO Selectivity of CO2 Selectivity of CH4 Selectivity of CH

3OCH

3

Conversion(%)

Con

vers

ion

(%)

Sel

ectiv

ity (%

)

Temperature (oC)

0

20

40

60

80

100

Figure 5: Selectivity and Conversion graph of methanol aerobic reaction over a 1wt% Au/ SiO

2

catalyst

5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

0 .0 0 E + 0 0 0

1 .0 0 E -0 1 0

2 .0 0 E -0 1 0

3 .0 0 E -0 1 0

4 .0 0 E -0 1 0

5 .0 0 E -0 1 0

6 .0 0 E -0 1 0

7 .0 0 E -0 1 0

C H4

C H3O H

C H3

H2

C O

H2O

Y A

xis

Title

T em p e ra tu re oC

Figure 6: Temperature Programmed Desorption for methanol oxidation over Au/ SiO

2 catalyst

54


1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0

0

1 0 0 0

2 0 0 0

Cou

nts

(a.u

)

2 th e ta / d e g re e s

S iO2

1 % w t A u /S iO2 u n c a lc in e d

1 % w t A u /S iO2 c a lc in e d

Figure 7: XRD patterns for SiO

2 and 1wt% Au/ SiO

2 (uncalcined and calcined) catalysts

(a) SiO2

(b) 1wt% Au/ SiO2 (uncalcined) (c) 1wt% Au/ SiO

2 (calcined)

Figure 8: XRD patterns for SiO

2 and 1%wt Au/SiO

2 (uncalcined and calcined) catalysts

55


Figure 9: Au (4f) spectrum for (a) 1wt% Au/ SiO

2 (uncalcined), (b) 1wt% Au/ SiO

2 (calcined)

catalysts prepared by deposition precipitation Table 1: Elemental composition for (a) 1wt% Au/ SiO

2 (uncalcined), (b) 1wt% Au/ SiO

2 (calcined)

catalysts prepared by incipient wetness impregnation Sample Atom % Wt % Si O Au Au (a) 29.9 70.0 0.1 1.0 (b) 30.2 69.8 <0.1 <1.0

Table 2: EDAX result for uncalcined 1wt% Au/SiO2 catalyst prepared by deposition precipitation

S/NO Sample Type Elements App Conc

Intensity Corrn

Weight % Weight% Sigma

Atomic %

1

1wt%Au/SiO

2

Bulk C K 3.0 0.3 26.0 2.1 35.0 O K 10.7 0.6 52.2 1.5 52.6 Al K 0.2 0.8 0.6 0.1 0.3 Si K 6.3 0.9 21.0 0.6 12.0 Ti K 0.04 0.8 0.2 0.04 0.1 Totals 100.00

2

1wt%Au/SiO

2

Spot O K 32.8 0.8 57.6 0.3 70.7 Al K 0.4 0.8 0.7 0.1 0.5 Si K 25.0 0.9 40.8 0.2 28.6 Ti K 0.1 0.8 0.2 0.04 0.1 Au M 0.3 0.6 0.7 0.1 0.1 Totals

100.00

CONCLUSION The adsorption and reaction of methanol on Au/SiO

2 catalysts indicate that the main adsorbed

species are methoxy which further react by bimolecular surface reaction and formed

dimethyl ether, which later decomposed to form CO, CH

4 and H

2. The presence of the Au on SiO

2

shows that the activation energy was reduced than when methanol oxidation reaction was carried out on SiO

2 alone.

REFERENCE Bowker. M, A. Nuhu and J. Soares (2007). High activity

supported gold catalysts by incipient wetness. Catalysis Today, 122 245-247.

Collins. S.E., M. A. Baltanas and A.L Bonivardi (2005), Applied catalysis A.: General 295 2 (2005) 126-133

James.D. E. Fourre, M. Ishii, and M. Bowker (2003), Ethene Adsorption Dehydrogenation and reaction with Pd(110): Pd as a Carbon ‘sponge’. Applied Catalysis, B: Envirnmental , 45, 147.

James. D, (2002); Selective Propene Oxidation on Metal Oxide Catalysts. PhD, University of Reading.

Nuhu. A, J.Soares, M. Gonzalez- Harrera, A. Watts, G. Hussien and M Bowker (2007), Methanol oxidation on Au/TiO

2 catalysts. Topics in

Catalysis, 44 1-2 Soares. J. M. C.; P. Moralla; A. Crossley; P. Harris; and

M. Bowker (2003); Methanol oxidation over Au/TiO

2 catalysts by Deposition precipitation.

J. of Catalysis, 17, 219, (2003). Sviatoslav. A, A. Kirillov, P. E. Tsiakaras and I. V.

Romanova (2003), FTIR and mass spectrometric studies on the interaction of formaldehyde with TiO

2 supported Pt and Au

catalysts J. of Mol. Structure 651-653 (2003) 365-570.

56


THE SYNERGISTIC EFFECT OF GOLD AND TiO2 IN LOW

TEMPERATURE CO OXIDATION OVER Au/TiO2 CATALYSTS

Abdullahi Nuhu Kano State University of Science and Technology, Wudil, P. M.B 3244, Kano State, Nigeria

E-mail:[email protected]

ABSTRACT The reactions and oxidation CO over Au/TiO

2 catalysts were investigated using pulse flow

reactor, SEM, EDAX, XPS, and TPD. The catalyst was prepared using Double impregnation method. The Pulse Flow Reactor results indicate that 100% conversion of CO was observed at sub ambient temperature and continue through out the experiment. The CO oxidation reaction over TiO

2 shows no results at low temperature indicating the inertness of TiO

2 for CO oxidation.

However, the presence of nano particles gold on TiO2 catalyst for CO oxidation increases the CO

oxidation reactions and minimises or lowers the activation energy of the reaction. The SEM, EDAX, XPS, XRD and TPD indicate that the gold is present in the catalyst in form of nano particles and in small size.

Keywords: Au catalysis, CO oxidation, CO Aerobic oxidation, TPD, DP and TPPR INTRODUCTION Gold has been regarded as a very inert metal. Consequently, the bonds between gold surfaces and adsorbate, such as CO and CO

2 are very

weak. Unlike the considerably stronger CO adsorption on palladium and platinum, reported that the bond between CO and the gold surface is almost entirely due to electron donation from molecular CO to the metal. The -bond between CO and gold weakens when the coverage increases. Consequently, a lower ‘direct donation’ contribution to the Au- CO bond strength causes a stronger C-O bond. In the low temperature range (i.e. 200K), CO oxidation catalyst with a highly dispersed gold phase are superior (with respect to activity) to the most active palladium, platinum or silver catalysts. Highly dispersed, metal oxide supported gold catalysts were found to catalyse various oxidation and hydrogenation reactions, in particular the CO oxidation, already at low temperatures (Bond, 1999), (Haruta, 2002)).It was further found that in addition to catalyst dispersion also the procedures for catalyst preparation and conditioning, and the nature of the oxide support play an important role, and it was possible to distinguish between ‘active’ easily reducible supports and the less active (‘inert’), stable oxides (Schubert et al. 2001). One of the most active support materials is titanium oxide (TiO

2). For instance, Au/TiO

2

catalysts were reported to be an active catalyst for CO oxidation even at 90K. The Au/TiO

2

catalysts (with gold particles sizes 1~10nm) are mostly prepared by co-precipitation or by deposition precipitation followed by calcinations in air at temperatures between 120oC and 400oC (Haruta et al. 1993), (Grunwaldt et al.1999),( Boccuzzi et al. 2001). The highly dispersed metal oxide supported gold catalysts are active and the temperature for CO oxidation’ is not commonly used for the temperature range from -65oC to 150oC 16 is denoted ‘low temperature CO oxidation’.

Masatake Haruta was the first to show that CO oxidation can be performed at ambient temperatures using gold dispersed on oxide surfaces. Many researchers are now using CO oxidation as a standard test reaction, and this early work has been extensively reviewed (Bond 1999).

Mechanism of CO oxidation on Gold Catalyst The reaction mechanisms of the CO oxidation on highly disperse Au/TiO

2 catalyst was studied in

numerous publications (Grunwaldt et al.1999),( Boccuzzi et al. 2001),( Kahlich et al. 1999).The CO oxidation results were seldom explained by a simple Langmuir-Hinshelwood mechanism for non-competitive adsorption, combined with an additional mechanism of oxygen activation1. This reaction mechanism comprises of the following elementary steps:

(i) CO + * CO* (ii) O

2 + * O

2*

(iii)O2* + * 2O*

(iv) O* + CO* CO2* + *

(v)CO2* + * CO

2

In some cases however, the CO oxidation results do not correspond with a Langmuir- Hinshelwood mechanism according to Tanielyan. Several uncertainties remain and various mechanistic models were developed. It is also not clear

whether the oxygen molecule is dissociatively or non-dissociatively adsorbed, but most likely molecular oxygen is adsorbed at the perimeter interface as reported by Haruta et al (2002).

57


Boccuzzi et al. (2001), ( Kahlich et al. 1999) and .Boccuzzi et al.intensively studied CO adsorption at 90K and room temperature by Fourier Transform Infrared Spectroscopy (FTIR). At 90K, CO adsorbs on the gold particles and on the TiO

2 support and they postulated a back spill

over from the support to the gold and a key role of support oxygen vacancies in the reaction mechanism. At room temperature, they found that CO molecules, which were adsorbed on terrace sites and on sites at the borderline of the gold particles, were active for CO oxidation. Boccuzzi proposes two different pathways for the oxidation of carbon monoxide. First, oxygen (activated on the surface of metallic gold particles) leading to the formation of CO

2.

Boccuzzi considers this mechanism to be the most important for low- temperature CO oxidation. Haruta showed that three-temperature regions exist where different kinetics (e.g.

different rates and apparent activation energies) apply. He proposes potential pathways for the oxidation of CO as shown by figure 1.The mechanisms of CO oxidation that have been devised to involved only the gold component are less complicated than those where the support is also implicated. Some of the mechanisms that involved gold alone were reported by many researchers. Kung et al. (2003), proposed a model based on the assumption that reactive ionic gold species (i.e. Au1 -OH) are present. Figure 1 indicates that hydroxyl carbonyl is oxidised to bicarbonates, which is then decarboxylated to Au1-OH and CO

2.

The active site is an ensemble of metallic Au atoms and Au-OH. Metallic Au atoms are responsible for activation of oxygen, probably at steps or corner sites. The simplified version of the mechanism (figure 1) can also be presented as follows:

(1) O-Au0-AuI-OH- + CO → O-Au0-AuI-COOH- (2) O-Au0-AuI-COOH- → Au0-AuI-COOOH- (3) Au0-AuI-COOOH- → Au0-AuI-OH- + CO

2

(4) Au0-AuI-OH- + 1/2 O2 → O-Au0-AuI-OH-

Haruta et al. (2002) postulated a model in which bidentate carbonates adsorbed on the support are important intermediates for CO

2 formation28:

(i) CO + *Au CO-*Au (ii) O

2 + *sup + e- O

2

--*sup (iii) CO-*Au + O

2-*sup CO

3

-*sup + *Au + e-

(iv) CO3

-*sup + *sup CO2

-*sup + O-*sup (v) CO

2

-*sup CO2 + *sup

(vi) 2 O-*sup O2 + 2*sup

G.C.Bond and D.T.Thampson (1999) proposed the following mechanism, involving gold-hydroxide groups. (i) Au0 + CO CO-*Au0 (ii) Au3 + OH-* OH-*Au2

(iii) CO-*Au0 + OH-*Au2 COOH-*Au2 + *Au0 (iv) O

2 + sup + e- O

2-*sup

(v) COOH-*Au2 + O2--*sup *Au2 + CO

2 + HO

2 -*sup

(vi) COOH-*Au2 + HO2-*sup Au2 + CO

2 + 2OH-*sup + sup

(vii) *Au2 + *sup + e- *Au3 +* sup There have been number of CO oxidation reactions on Au/TiO

2 support. A number of the

publication supported the idea of a Langmuir- Hinselwood mechanism; (Haruta et al. 2002). oxygen molecules adsorb at the particles edge, the O-O bond being stretched by electron transfer from gold, initiated by the presence of Ti cations and oxygen vacancies at the interface. Other reactions show the lattice expansion in the gold particle due to mismatch with the lattice of the support, as was observed with Au/MgO (100)

and with Au/ anatase-TiO2 (110); this was

thought to increase the effectiveness of gold in catalysing CO oxidation. Similarly, studies by EXAFS have shown that supported gold particles demonstrate contraction of the gold-gold lattice distances when the particle size becomes smaller than 3nm (Miller et al. 2006).

However, J.M.C.Soarers et al. (2003) also reported the catalytic contribution for CO

oxidation in our group earlier. The study particularly focused on catalytic and noncatalytic CO oxidation on Au/TiO

2 catalysts.

MATERIALS AND METHODS Catalyst preparation In this method, 5g of Degussa P25 titania was impregnated with 1.25mL of 0.08g/mL HAuCl

4.3HO solution while gently stirring the

powder; note that this is insufficient liquid to fill the pores. Subsequently, 1.43mL of Na

2CO

3 I M

solution was then added while continuing to stir the paste. This total volume of liquid was then just sufficient to fill the pores of the powder to the incipient wetness point. The mixture was next washed on a vacuum filter with 14 mL of the sodium carbonate solution in 100mL of water and this was repeated five times, followed by five washings with 100ml of water.

58


The paste was left to dry overnight in air at ambient temperature and was further dried at 120oC in air for 2h. Some samples were used directly in this form; others were further calcined to 400oC in air for 2h. The amount of gold added in the catalyst preparation was equivalent to 1wt% of Au.

CO oxidation The reactivity of the catalyst was tested using a pulse flow reactor, which has been described in detail elsewhere (Soarers 2003). 0.5g of the pressed catalyst was held vertically in a U- tube within the oven of the reactor. 10% O

2/He gas

was flowed at a rate of 30 ml per minutes. CO was injected using pulsing valve periodically (2 minutes intervals) in to the gas stream. At the beginning, the gas stream passed through the bypass until the mass spectrometer signal had settled. The gas stream was then switched to over the catalyst and the products of methanol oxidation were observed using a quadrupole mass spectrometer. RESULTS AND DISCUSSION Temperature Programmed Pulsed Flow Reaction The oxidation of CO was carried out over a 1wt%Au/TiO

2 catalyst, prepared by double

impregnation. However, to understand the role of Au and synergy between gold and TiO

2 on CO

oxidation, TiO2 was used alone as a catalyst. The

Temperature Programmed Pulse Flow Reaction result was carried out .it was observed that the aerobic CO oxidation (in 10%O

2/He flow) showed

that low intensity CO2 peaks were observed at

room temperature. However, as the temperature was increased, more intense CO

2 peaks observed.

Similarly, the anaerobic temperature programmed pulse flow reaction for CO reaction over TiO

2 catalyst (in the absence of oxygen in

the stream) indicated that low CO2

signals observed through out the experiment. When the data in aerobic and anaerobic CO oxidation were integrated and analyzed, figure 3 is obtained.

Similarly, aerobic temperature programmed pulsed flow reaction for CO oxidation was carried out over 1wt%Au/TiO

2

catalyst. Two set of experiments were obtained. During the first run, high conversion of CO was observed at room temperature; almost all the CO pulsed over the catalyst has been converted to CO

2. However, as the temperature increased,

more CO2 was produced with 100% conversion of

CO to CO2, and continue through out the

experiment in a steady state. After the first run, the catalyst was

cooled down and the second run of the experiment were obtained. It shows that not all the CO converted to CO

2 at room temperature;

this is because after the first run, the catalyst lost some activity. The raw peak areas of both runs was integrated and analysed and the CO

2 yields

are presented in figure 4 Similar results were obtained when the

catalyst pre-treated in air at 400oC before the

activity test. The CO oxidation reaction over Au/TiO

2 catalyst occurred with no evolution

hydrogen gas but with some water evolved during the course of the reaction.

In order to understand the active surface oxygen of CO oxidation reaction over Au/TiO

2

catalyst, a freshly prepared 1wt% Au/TiO2 catalyst

was loaded in the reactor and the temperature programmed pulse flow reaction of CO was carried over the catalyst in a flow of He alone (anaerobic) and even in the absence of gas phase oxygen, there are two stages of CO

2 being

produced. One at ambient temperature (stage I) but as the temperature was increased, the CO

2

drops slightly until the temperature reached 100oC from which the stage II CO

2 emerge and

remained in a steady state through out the experiment. But when the second run was done, the stage I CO

2 production at ambient

temperature was not observed and may be attributed to the absence of the active surface oxygen that has been used off and no longer there. However, when the temperature was increased, stage II CO

2 production occurred

which is due to catalytic activities. It implies that the active oxygen for the CO oxidation is coming from the sample not due to catalytic activity. it is also evident that the active oxygen responsible for CO

2 produced (First and Second

stage) are two types, one loosely bound on the surface and the other the gas phase oxygen must be present for consumption for CO

2 production

and is due to true catalytic activity. The results are in agreement with the data obtained by Soarers et al. (2003).

When the first and second runs were integrated and analysed, figure (5) was obtained. The figure shows that during the first run, the CO

2 yield for the stage I is about 30% at ambient

temperature, then fall with time and increased with temperature. However, as the stage CO

2

emerged at about 200oC, the CO2 Yield was about

98% and then drops as the temperature was increased until it reached about 300oC and then continues in a steady state. Nevertheless, during the second stage I CO

2 was not observed at

ambient temperature because the active surface oxygen was used during the first run and as the temperature was increased to 200oC, more CO

2

(stage II) was obtained with yield value of 98%, higher than the first run. The CO

2 yield (stage II)

has been due to catalytic reaction involving the support oxygen and CO as confirmed by the XPS, which only shows reduction of support surface. However, the anaerobic CO oxidation over a 1wt% Au/TiO

2 catalyst produced CO

2 together with a

massive production of hydrogen. The hydrogen production was observed in the first and with the highest production observed in the second run experiment of the anaerobic CO oxidation reaction over a 1wt% Au/TiO

2 catalyst. The

hydrogen produced may be due to the following reactions either between the hydroxides of the catalyst or due to water gas shift as shown below in equation 1 and 2:

59


Au (OH)

3 Au3+ + 3OH –

2OH +2CO 2CO2 + H

2

1. . CO + H

2O CO

2 + H

2

oH

OOH

Au0

Au

OH

O

O

COOH

OO

COH

OH

O

CO2

CO

O2

Figure 1: The Kung Mechanism of CO oxidation24

TIO2

C

OC

O

C

O

OO

CO2 OO

O O O

C

O

spectator

intermediate

surface

perimeter

Au

Figure 2: Mechanism proposed by Haruta et al28.

60


50 100 150 200 250 300 3500

5

10

15

20

25

30C

O2 Y

ield

(%)

Temperature oC

CO2 Yield (%) for aerobic CO oxidation on TiO

2

CO2 Yield (%) for aerobic CO oxidation on TiO

2

Figure 3: Comparison of CO

2 yield (%) with temperature for CO pulses in a stream of 10%O

2/ He

(aerobic) and He (anaerobic) flow over TiO2 catalyst

0 50 100 150 200

0

20

40

60

80

100

CO

2 Yie

ld (%

)

Temperature (oC)

First run Second run

Figure 4: CO

2 yield (%) with temperature for CO pulses in a stream of 10%O

2/He flow over a 1%wt

Au/TiO2 catalyst dried at 120oC in air.(1st and 2nd run)

61


5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1 0 0

1 1 0

S tag e I C O2

S ta g e II C O2

CO

2 Yie

ld (%

)

T e m p era tu re (O C )

F irs t R u n S e co n d R u n

Figure 5: CO

2 yield (%) for CO pulses in a stream of He flow over a 1wt% Au/TiO

2 catalyst dried at

120oC in air. (First and second run)

CONCLUSION From the foregoing, we are able to understand that Au/TiO

2 catalyst prepared by deposition

precipitation is good for CO oxidation. It was also possible to identify that two type of CO

2

produced; one at low temperature (stage I CO2)

and the other at relatively high temperature (stage II CO

2).Both types of CO

2 produced, with

stage I CO2 was due to stoichiometric reaction

and the other (stage II CO2) due to catalytic

reaction. Similarly, the two types of CO2 produced

are observed for the catalyst pre-treated in air at 120oC or 400oC. However, the catalyst of Au/TiO

2

prepared by deposition pre-treated in air at 120oC shows better activity with respect to CO oxidation. However, the two types of CO

2

produced (stage I and stage II), were due to stoichiometric and the other due to catalytic reaction respectively.

REFERENCES Boccuzzi. F and A. Chiorino, M. Manzoli, P. Lu, T.

Akita, S. Ichikawa, and M. Haruta, (2001) Au/TiO

2 Nanosized Samples: A Catalytic,

TEM, and FTIR Study of the Effect of Calcination Temperature on the CO Oxidation. J. Catal. 202, 256

Bond, G. C.; Thompson, D. T. (1999). Catalysis by Gold . Catalysis Reviews: Science and Engineering 41 319-388

Bond, G. C.; Thompson, D. T. (1999). Catalysis by Gold . Catalysis Reviews: Science and Engineering 41 319-388

Grunwaldt J.-D and A. Baiker, (1999) Gold/Titania Interfaces and Their Role in Carbon Monoxide Oxidation. J.Phys.Chem. B. 103, 1002

Haruta, M. CATTECH 6 (2002) Catalysis of gold nanoparticles deposited on metal oxides. 6 102-115

Haruta. M, S. Tsubota, T. Kobayashi, H. Kageyama, M. J. Genet, and B. Delmon, (1993). Low-Temperature Oxidation of

CO over Gold Supported on TiO2, α-Fe

2O

3,

and Co3O

4 .J. Catal. 144, 175

Kahlich. M.J. H. A. Gasteiger, and R. J. Behm., (1999). Kinetics of the Selective Low-Temperature Oxidation of CO in H

2-Rich

Gas over Au/α-Fe2O

3. J. Catal., 182, 430

Kung H. H. and C. K. Costello, (2003), CO oxidation. J. Catal., 216, 1-2

Miller. J. T. A. J. Kropf, Y. Zha, J. R. Regalbuto, L. Delannoy, C. Louis, E. Bus and J. A. van Bokhoven, (2006), The effect of gold particle size on Au Au bond length and reactivity toward oxygen in supported catalysts. J. Catal. 240, 222

Schubert. M. M., S. Hackenberg, A.C. van Veen, M. Muhler, V. Plazak, and R.J.Behm, (2001). CO Oxidation over Supported Gold Catalysts—“Inert” and “Active” Support Materials and Their Role for the Oxygen Supply during Reaction J.Catal. 197, 113

Soares, J. M.C. P. Morrall. M. Bowker (2003) , Catalytic and noncatalytic CO oxidation on Au/TiO

2 catalysts. J. Catal. 219, 17-24

ION EXCHANGE APPLICATIONS OF ZEOLITE 62


Danjuma, M.N. Department of Chemical Engineering, Kaduna Polytechnic, Kaduna.

ABSTRACT Zeolite is inorganic exchangers with dimensional frame work. The rigid structure undergoes much less shrinkage or swelling when used as ion exchanger. In this research, the cation exchange capacity based on theoretical formula and total exchanged capacity as a method of characterizing zeolite was given a thought. Also, the properties of zeolite as an ion exchanger were equally looked into. Zeolite as an ion exchanger and will continue to be of great scientific and technological importance especially in the field of purification, separation, environmental pollution control, pharmaceutical and industrial processes. Key words: Zeolite, Cation exchanger, Cation exchange capacity, Cystalline structure, ion exchange. INTRODUCTION Zeolites are crystalline microporous solids containing cavities and channels of molecular

dimensions – 3 to o

A10 . These materials have high thermal and chemical stability, making them useful materials in a wide range of important industrial processes, such as catalysis, separation, purification and ion exchange (Vaughan, 1988). Zeolites are crystalline inorganic

polymers based on a frame work of 4XO

tetrahedral linked to each other by the sharing of oxygen ions, where X may be trivalent (e.g. Al, B, Ga), tetravalent (e.g. Ge, Si), or pentavalent (e.g. P). The crystal structure of a zeolite is defined by the specific order in which its network of tetravalent units is linked together. (Chen and Degnan, 1988). The primary building block of the zeolite structure is a tetrahedron of four oxygen atoms

surrounding a central silicon atom ( ) −44SiO .

These are connected through their corner of shared oxygen atom to form a wide range of small secondary building units. Different combinations of the same secondary building

unit may give numerous distinctive zeolites. Added complexity is provided by other element (X – substitute) restricted by the limitation that the cation of the element in question will fill into the space at the center of the four tetrahedral oxygen atoms without too much strain, and that the resultant structure will be electronically

neutral. 2SiO is neutral, but substitution of

+3Al for +4Si result in a single net negative

charge on the frame work, which is compensated

by a “non frame work” cation (e.g. +Na ) that is

located in the pores or cavities of the structure. Since this cation is not locked into the framework

by a “box” of four oxygen atom as is the +4Si

or+3Al , these charge compensating cation are

relatively mobile and can in many cases be easily exchanged for other cation (Vaughan, 1988). The size of the zeolite pore opening is determined by: The number of tetrahedral unit or alternatively, oxygen atoms, required to form the pore; and the nature of the cations that are present in or at the mouth of the pore. Zeolites are commonly lumped into three classes.

Number of Tetrahedral Max free Diameter Small 6.8

4.3o

A Medium 10

6.3o

A Large 12

7.5o

A Zeolites with more than one pore system are classified according to their largest accessible pore (Chen and Degnan, 1988).

Cation Exchange Is a process in which cations in solution are exchanged with cations held on the exchange sites of mineral and organic matter, particularly on the surfaces of clay or matrix. Computation of Cation Exchange Capacity of a Given Zeolites Based on Theoretical Formulae Every exchanger has a maximum amount of charged site per gram of exchanger; this value is

called the theoretical specific capacity. The capacity is identical to the charge density due to inorgenic groups. The Cation Exchange capacity of a given zeolite can be computed using the number of equivalents cations exchangeable for each formulae unit divided by the molecular weight of a formulae unit.

63


( )Weight Molecular Relative

leExchangeabCation Equivalent of No... =QCEC

Example Clinoptilolite zeolite with the following molecular formulae

( )( ) 024. 29640633 HOSiAlKNa

This formulae contain KNa 33 + are exchangeable or 6 equivalents of cation are exchangeable. The molecular weight was obtained as 2774.37g. The C.E.C (Q) was obtained as 0.00216 equivalents per gram or 216 equivalents per 1gram or 2.16 milli-equivalents (Meq) per gram. The calculated C.E.Cs for common zeolites, based on the theoretical formulae and their corresponding pore sizes were presented in table below (GSA Resource, 2004).

Total Ion Exchange Capacity The total ion exchange capacity of material is usually expressed as milli-equivalents per gram of exchanger. This will be determined by treating a known mass of exchanger with diluted mineral acid. Treated exchanger is percoalated with a solution of Na

2CO

3 and the effluent is titrated

with solution of NaOH in a process known as zeo-karb 225 in hydrogen form. The total exchange capacity is then computed with the formulae.

wav …………………………………………………… (1)

where “a” is the normality of NaOH solution, v is the volume in ml and w is the weight (g) of the exchanger (Dara, 1991). ZEOLITES AND THEORETICALLY BASED C.E.Cs

Zeolite Formulae C.E.Cs (meq/g) Pore Size

o

A

Clinoptilolite ( )( ) OHOSiAlKNa 29640633 24• 2.16 64×

Mordenite ( )( ) OHOSiAlNa 2964088 24• 2.29 76×

Erionite ( )( ) OHOSiAlKCaNa 272279233 27• 3.14 8.3

Chabazite ( )( ) OHOSiAlKNa 272241266 40• 3.70 4

Phillipsite ( )( ) OHOSiAlKNa 264221065 20• 3.87 3

Foujasite ( )( ) OHOSiAlNa 23841345858 240• 3.39 7.4

Synthetic Zeolite A ( )( ) OHOSiAlNa 248121212 27• 5.48 4.2

Synthetic Zeolite X ( )( ) OHOSiAlNa 23841068686 264• 4.73 7.4

Sodalite ( )( ) OHOSiAlNa 224666 75• 6.08 2.2

Laumonite ( )( ) OHOSiAlCa 2481684 16• 4.25 2.2

Source (GSA Resource Inc, 2004) and (Breck, 1974) The total ion-exchange capacity of material is usually different from the value of that of theoretically based cation exchange capacity. The exchange capacity of climoptilolite was found to be 1.3meg/g experimentally which differs from 2.16meg/g as obtained theoretically.

Ion Exchange Equilibrium An ion exchanger is an insoluble material (R) that has ionogenic group to which counter ions (A) can be found (IUPAC). When liquid is contacted with ion exchanger an ions C and A are exchanged.

xyyx yAxRCxCyRA +→+ ……………………………………. (2)

Removal of Ion From Solution Removal of ion from solution by ion-exchanger is affected by many factors among other are selectivity of the exchanger, steric factor, concentration of the cation in the solution and sieve nature of the exchanger (Danjuma, 2005). Selectivity

Selectivity is a characteristic of an ion exchanger; which makes the exchanger prefer one counter ion to another; thus selectivity drives the reaction in equation (2) either to the left hand or right hand side. The selectivity coefficient for A/C ion exchange in equation (2) above can be written using mass-action law with activity correction, thus.

64


[ ] [ ][ ] [ ]yx

yx

ACRAC

ARCK = ……………………………………………… (3)

The selectivity coefficient depends on experimental conditions, and the value of the coefficient can vary in the range of a few orders of magnitude. The most important factors for selectivity towards metal cation are electric interations between ion and exchanger, pore structure and elasticity of the exchanger and other interactions between exchanger and ion. Electric interactions occurred due to the following.

i. Electro-selectivity: This is due to the Donnan potential in the electric field between the exchanger and the electrolyte solution. The concentration of counter ions (cations) is larger in the exchanger and the concentration of co- ions (anions) is larger in the solution. Electric potential difference between the two phase exist when ions migrate from one phase to another. The potential pulls counter ions to the exchanger and excludes the co- ions from the solution. The force of interaction for ions is proportional to the valence of the ions and this give a preference for ions with higher valences. The Donnan potential increase with increasing exchange capacity (Http://ethesis’’html)

ii. Electrostatic attraction: Is interaction between counter ion and ionogenic groups in situations where the character of the interaction is only weakly chemical. The

force is proportional to the ion exchange capacity, which produces a higher charge density in the exchanger. Electrostatic attraction prefers ions which higher valences smaller ions and ions with stronger polarization (Http://ethesis’’html)

iii. Sieve nature of exchanger: in order to replace the original protons, the cation present in the external solution must diffuse through the windows connecting the cavities. The water molecules of the hydrated ions are exchanged frequently with the bulk water molecules in the solution. The exchanging ion can pass through the window of the cavity, when some or all water molecules are stripped from hydrated ions, if the counter ion has larger crystal ionic radii than the opening of the window ion sieve effect can occur.

Experiment with sodalite shows Li+

, Na+ K+

and Ag+ diffuse readily into zeolite structure, while Ti+ Rb+ and CS+ with great difficulty. (Dyer et al, 1993). Distribution Coefficient and Practical Capacity The distribution of metals between solution and solid depends on the selectivity of the ion exchanger. In certain experimental condition, for trace ion exchange, a useful measure for metal distribution is the distribution coefficient (K

D)

which is defined thus:

[ ][ ] [ ]gmlC

RCK D = …………………………………………… (4)

Where R is ion exchange material as in equation (2)

When ion C is present at trace level, then selectivity coefficient ACK is constant then

( )

[ ] xy

xyAC

DA

QKK

1

= ………………..…………………………… (5)

Here DK is inversely proportional to [ ] xyA . DK is used to evaluate the efficiencies of

various exchanger (Http://ethesis’’html) Loaded Capacity The capacity that can be loaded with the metal involved, in certain experimental conditions, is called the practical specific capacity

AQ [ ]gmeq / which is usually experimentally

determined from this practical capacity, it is possible to calculate the maximum processing

capacity PQ [ ]gml / of the column operation, in

terms of solution volume that can be purified from ion C with a given mass of exchanger.

[ ]iA

P C

QQ = …………………………………………………. (6)

where [ ]iC is the initial concentration of solution [eq/l].

DK value can be used to estimate solution volume that passed through the column at 50oC

breakthrough, V50

using the following equation.

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eD M

VK 50= ………………………………………………… (7)

Where Me is mass of breakthrough (Http://ethesis’’html)

Rate Of Ion Exchange Some important assumptions were made in the derivation of this equation these are: 1. The factors limiting the rate of ion exchange are

those which limit the rate at which ion transported to the interface between the ion exchange particle and the liquid, by what every mechanism this transport is accomplished.

2. For either phase, this transfer may be described by a rate equation of the form:

[ ]iCCAK −′= Rate

Where K ′ = mass transfer coefficient A = Area C = Concentration in bulk of phase of material

being transferred,

iC = Concentration at inter phase of material

being transferred. 3. Equilibrium exists at the interface for the

exchange of sodium ions in solution for hygrogen ions in the resin phase.

Using these assumption an equation for the rate may be expressed in the form

( ) ( )

−−−= CC

k

ccck

dt

cd01

where the rate constant, k is

( ) ( )KROL KCKaK

+= 1

The group a/kL represent the liquid-side resistance

and KL contains those factors which determine the

rate at which ions are transported from the body of the liquid to the liquid-solid interface. Similarly, C

0/K

KR is the solid-side resistance, and K

R contains

the factors which determine the rate at which ions are transported from the body of the particle to the solid-liquid interface. The sum of these two represents the total resistance, and by inspection, the difference between the products of concentrations represents the net driving force for the exchange, (Gilliland and Baddour, 1953)

Properties of Ion-Exchanger Hydraulic properties, physical properties and chemical properties are needed to evaluate the suitability of an ion exchanger. Hydraulic properties: This depend on particle density and particle-size distribution etc it is used to predict proper fluidization head spaces and backwash flow rate, as well as pressure drop through ion exchange bed. Physical properties: This shows the ability to resist bead fracture and fragmentation in service. This

includes crushing strength, sphericity after attraction, osmotic shock testing and microscopic examination. Chemical properties: This includes total capacity, salt-splitting capacity and water retention capacity. These test are perform to saturation level and they reveal the theoretical chemical capabilities of the ion exchanger (resin). That help in determining operating capacity from empirical correlation, (Lefevre,1986).

CONCLUSION Zeolite as an ion exchanger will continue to be of great scientific and technological important especially in the field of purification, separation, environmental, pharmaceutical and industrial processes. Selection of a zeolite type for a specific purpose is very important. This can be achieved by characterizing and evaluating the cation exchange capacity of the zeolite to ascertain it suitability for the choosen purpose. This work provides a frame work for such evaluation.

REFERENCES Breck; D.W; (1974) “Zeolite Molecular Sieve” John

Wisley, New York Pg 16-23 and pg 45-51 Chen, N.Y. and Degnan, T.F. (1988) “Industrial

Catalytic Applications of Zeolites”. Chemical Engineering Progress, Zeolite Issue, Vol. 84 No. 2 Pg 32 – 40.

Danjuma, M.N (2005) “Development of Matrix for the Treatment of Textile Effluent, M.Sc Thesis submitted to Department of Chemical Engineering, A.B.U, Zaria. Pg 55

Dara, S.S (1991) “A Text-Book on Experiments and Calculation in Engineering Chemistry, S. Chand & Company Ltd New Delhi Pg 148 – 150

Dyer. A., Hudson, M.J and Williams P.A. (1993) “Ion Exchange Processes: Advances and

Applications, Published by Royal Society of Chemistry Cambridge Pg 205.

Gilliland, E.R and Baddour, R.F (1953). “The Rate of Ion Exchange”, Industrial & Engineering Chemistry, Volume 45, Pg 330 – 331.

GSA Resource Inc, “Cation-Exchange Capacity of Zeolite. Pg 1-4, retrieved June,27,2004 from File://A:/Cation-Exchange.htm

Ion exchangers and their use in waste water treatment ,pg1-9, retrieved Nov,23,2006. From http:// ethesis . Helsinki. fi/julkaisut/mat/kemia/vk/leinonen/3luku.html.

Lefevre, L.J (1986). Ion Exchange: Problems and Troubleshooting, Chemical Engineering. Pg 73-75.

Vaughan, D.E.W (1988) “The Synthesis and Manufacture of Zeolites, Chemical Engineering Progress, Zeolite Issue; Pg 25-31.

66


EXTRACTION AND CHARACTERIZATION OF CALABASH (Lageneria siceratia) SEED OIL

Danjuma, M. N. and Dandago, M. A. Chemical Engineering Department Kaduna Polytechnic, Kaduna.

Food Science and Technology Department, Kano University of Science and Technology, Wudil, Kano State.

ABSTRACT The work was aimed at extraction and characterization of oil extracted from calabash (Lagereria siceratia) seeds. The extracted oil was characterised and the result obtained showed the refractive index to be 1.482, specific gravity to be 0.74, boiling point to be 148oC and melting point to be 28°C while the average oil yield was found to be 22.32%. The result of chemical analyses of the oil showed an Acid value of 2.02 mg/g which falls within the standard value for edible oil; pH value of 6.6, which justify the low free fatty acid value of 1.01mg/g obtained. The saponification value of 229.6mg/g obtained indicated the suitability of the oil in soap production while iodine value of 75.2mg/g indicated the suitability of the oil for consumption.

Key words: Extraction, Characterization, Saponification value, free fatty acid, Neutralisation, Iodine value.

INTRODUCTION An attempt to improve the data base for seed oil available for various purposes either for consumption, soap production; Bio diesel production etc necessitated this work. Calabash is classified to the kingdom of plantae, division of magnoloiophyta, class of mognliopsida, order of cucurbitacles, family of cucurbitaceous, genus of lagenaria and species of Lagenaria siceraria. Calabash is one of the first cultivated plants in the world, grown not for food and as a container’. (Fran and Wilf, 2008).

The plant is found in abundant in Gumi (Zamfara State), Dukku (Gombe State), Laminga, Keffi (Nassarawa State) and many Northern part of Nigeria. The fruits are ready for harvest in 100 – 120 days after sowing (Korchar, 1985). Oil which was found in plant is mostly found in storage organ such as seeds and they occur mainly in adipose tissue and have to be extracted.

MATERIALS AND METHODS Preparation of raw material, 150g of the dehulled seeds was grinded into various sizes and the size was determine using endocot sieve, Extraction of oil Fifty grams of 1mm size of calabash seed was placed in a thimble of soxhlet apparatus and extracted with petroleum ether at 80°C for 2 hours. The same procedure was repeated with a sample of 2mm and 3mm particle sizes respectively. Characterization of the oil extracted pH Determination pH meter ELE model 3071 was used. It was standardized using a buffer solution. The pH meter electrode was then dipped into a

measuring cylinder containing 80ml of the oil sample to be analysed and the corresponding reading obtained was recorded. Boiling Point Determination Eighty millilitres of the extracted oil was measured into 100ml beaker and placed on a heating mantle and heated. The temperature at which the oil boiled was recorded. Melting and Solidification Point Eighty millilitres of oil sample was measured into 100ml beakers and thermometer was inserted and was placed in a refrigerator. The temperature at which the oil solidified was recorded. The whole content of solidified oil was transferred into a heating mantle and heated, the temperature at which the oil melted back to liquid was recorded. Specific gravity Twenty grams of extracted and refined oil was measured, its volume determined. Mass of equal volume of water was measured, the specific gravity of the oil was obtained form the following equation:

Specific gravity = Weight of oil (Kg) Weight of equal volume of water (Kg) Refractive Index Abbe refrectometer was used to determine the refractive index of the extracted oil. Yield of Oil Fifty grams of the dehulled sample was dried in a tray drier for 4 hours at 80ºC. The seed was crushed and oil was extracted for 2 hours using Soxhlet extraction apparatus. The weight of extracted oil was recorded and the yield was determined using:

% yield = weight of oil (g) X 100 Initial weight of sample (g)

67


Determination of Acid Value Five grams of the extracted oil was placed into a 250 ml conical flack and 50ml of neutral alcohol was added. The flask was heated over a water bath for 30 minutes. The flask was allowed to cool with the contents to room temperature and

3 drops of phenolphthalein indicator was added. It was titrated with the standard 0.1M KOH solution until a faint permanent pink colour appears at the end point. The calculation was done using the following equation:

Acid Value = Vol. of KOH run down X 5.6 Weight of the oil taken (g) Where 5.6 is constant And free fatty acid was calculated using the equation below: % free fatty Acid (FFA) = Acid Value 1.99 Where 1.99 is constant

Determination of Sapanification Value Five grams of oil sample was transferred into 250 ml flask fitted with reflux condenser and 50ml of 0.1M alcoholic KOH solution was added into the flask. The content was refluxed over a water bath

for 1 hour and the flask was removed from water bath. The inner wall of condenser was washed into the flask. Three drops of phenolphthalein indicator was added and titrated with 0.1M HCl until the solution becomes colourless.

Blank titration was also carried out and the saponification value calculated thus:

Saponification Value = (b - a) x 561 x M Weight of sample Where: a = Volume in ml of HCl run down in text experiment. b = Volume in ml of HCl run down in the blank experiment. M = Molarity of KOH. 561=Constant

Determination of Iodine Value One gram of the oil sample was placed into a 500ml glass – stoppered iodine flask, 25 ml of CCl

4 and 25 ml of wij’s solution were added into

the 500ml flask containing the oil with the help of a vacupet. The stopped flask was allowed to stand in dark for 2 hours. Twenty millilitres of potassium iodine solution was added; 100 ml of

water was then added with shaking. The excess of iodine was titrated with 0.1M Sodium thiosulfate solution using starch as indicator. The blank experiment was performed simultaneously by repeating the entire procedure without using the oil. The iodine value was calculated as:

Iodine value = (b - a) x M x 126.9 Weight of sample Where: a = Volume in ml of sodium thiosulfate run down in the first test experiment b = Volume in ml of sodium thiosulfate run down in the blank experiment M = molarity of sodium thiosulfate. 126.9= Constant

RESULTS AND DISCUSSION The result obtained from the analyses of the oil is presented in table 1 below: Table 1: values obtained for various analyses and the standard value from the literature

Properties Values obtained Standard values Boiling point 148°C - Melting point 28°C - pH value 6.6 - Refractive index 1.482 1.45 – 1.50 Average yield 22.32% 32% Specific gravity 0.74 Less than 1.0 Saponification value 229.6mg/g 170 – 260mg/g Iodine value 75.2mg/g 50 – 140mg/g Acid value 2.02mg/g 0.2 – 50mg/g Free fatty Acid 1.01mg/g 0.4 – 45 mg/g Saturated Acid Content - 19.7% Oleic Acid - 59.4% Linoeleic Acid - 19.3% Linolenic Acid - 1.6%

The result of the analyses of extracted oil from calabash seed as shown in table 1 indicates the boiling point of the oil to be 148ºC, melting point of 28ºC and pH value of 6.6. The value of

pH indicated that the oil is slightly acidic indicating the presence of small amount of free fatty acid.

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Refractive index which shows the purity of oil was found to be 1.482 which falls within the standard range for vegetable oil 1.45 – 1.50. The specific gravity of the oil was 0.74 and this conforms to the standard value of less than 1.0. The average yield of the oil was found to be 22.32% which was less than the expected literature value of 32%, this could be attributed to the high moisture content in the seed as the seed was not optimally dried and the maximum extraction period could not be used due to intermittent power supply.

The saponification value of 229.6 mg/g was obtained which fall within the standard value for vegetable oil of 170 – 260 mg/g. Saponification value indicates the quantity of fatty acid present in the compound oil. The result showed that the oil is suitable for soap production and other uses. The iodine value obtained was 75.2 mg/g which fails within the standard value of 50 – 140 mg/g. Iodine value shows the measure of unsaturation in oil. The value obtained justified similar experiment which

was conducted by the U.S Department of Agriculture (Smith and Dollear, 1947). The Acid value of the oil was found to be 2.02 mg/g, which fall within the standard value of 0.2 – 50 mg/g. The acid value shows the free fatty acid present in oil. The result is in agreement with pH value obtained. The result of free fatty acid was found to be 1.01 mg/g this fall within the range of standard value of 0.4 – 45 mg/g. This low acid value and mild pH of the oil makes it suitable for human consumption.

CONCLUSION AND RECOMMENDATIONS Based on the results of analyses conducted, it can be concluded that extraction of oil from calabash seed could reduce the pressure and over dependence on the available seeds used for vegetable oil extraction for human consumption. It will also boast soap production and supplement the oil base for Bio diesel production and lubricating oil. More research on the oil is recommended in order to fully utilise it.

REFRENCES Dara, S.S (1991). Experimental and calculation in

Engineering chemistry, S. Chand and company Ltd New Delhi, 3rd edition Pp. 138 – 142.

Fran, Z. S. and Wilf, S.(2008).Minor Oil Crops. Retrieved on 21/01/08 from http: // www.fao.org/docrop

Kochar, S.L. (1993). Tropical Crops. Harriman Publishers Nigeria. 2nd edition Pp. 102 – 115.

Opala, J. (2008).Calabash. Retrieved on 21/01/08 from http: len.wikiped.a.org/wiki/calabash.

Smith, B.A. and Dollear, F.G. (1947). Journal of American oil chemists society. 24(2): 52 – 54.

69


HOUSEHOLDS DOMESTIC ENERGY SOURCES IN WUDIL TOWN, KANO STATE

Tukur, A.I. Department of Geography

Kano University of Science and Technology, Wudil. Kano State. [email protected]

ABSTRACT This research investigated the household’s sources of energy in Wudil town. Using a structured interview with 80 households in Cikin Gari, Sabon Gari, and GRA areas of Wudil town, and field observation, the study investigated the major energy sources and types used by the households. The study revealed that fuel wood is the most dominant domestic energy type used by the households and also shows that the relationship between per capita income and per capita fuel wood consumption does not hold, as all the respondents (100%) indicated wood as their main source of energy. It appears that households with 15 to above family size use more fire wood (40%) than others. Also education level shows no impact on fuel wood consumption as all the respondents uses firewood. The alternative source of modern energy was found to be unaffordable to many households due to high poverty level. It is recommended, among other things, that energy policy and development projects aimed at reducing fuel wood dependency in Wudil town and the nation in general for sustainable environment should work not only to increase the supply of modern energy but also make them affordable by reducing the poverty level of the poor households.

Key Words: Households, Consumption, Energy, Fuel wood, Policy.

INTRODUCTION Access to and use of a cleaner energy remains the major issues in discussion about sustainable economic development and environment (Spalding-Fecher et-al, 2005). A recent estimate by the International Energy Agency (IEA, 2002) reveals that around 2.4 billion people in developing countries are still dependent on biofuels as their main energy source. Spalding-Fecher et-al (2005) observed that the main challenges facing the global energy sector are two fold; namely; to increase access to affordable modern energy services to poor countries that lack them, and to find the mix of energy sources, technologies, policies, and behavioral changes that will adverse environmental impact of providing the necessary energy services. In Nigeria, the use of fuel wood as a domestic source of energy is regarded as an indicator of poverty, wood is still the most readily affordable sources of domestic energy for the masses in the country, and may remain in the unforeseeable future (Falola, et-al, 1984). According to United Nations Development Programme, World Bank, and FAO estimates (Earl 1975: 10) more than 90% of Nigerian energy is supplied by wood. The annual rate of deforestation in Nigeria averages 3.5%, based on this, it has been estimated that the country will lose all her forest by the year 2020.. One of the main reasons for this lack of inter-fuel substitution is that, household choice and use of a given source of fuel hinges on a host of socio-economic (e.g income and wealth), demography (e.g family size, household consumption, life style, and culture), and location attributes (e.g proximity to source of modern and traditional fuels) besides its availability (Kerekezi and Majoro, 2002). In fact this statement may

also hold true in the Nigerian context as the country has different climates, and a diverse mix of ethnic, religious, and linguistic backgrounds. At the same time, the country is characterized by high-income inequality in both the rural and urban sectors. In Kano region , studies of rural-urban commodity flows conducted in 1965 and 1969 had show that fuel wood either cropped from living trees or obtained by cutting down dead or living trees in the close settled zone , made up a large proportion of total domestic energy consumption, especially in the Birni (Faloa et-al 1984) The result demonstrated clearly the wide use of fire wood and charcoal in rural areas as well as in the urban centers including big towns, where mean monthly consumption of fire wood in a sample of 80 households was found to be 332kg (Falola et-al, 1984). However, the factors influencing the pattern and magnitude of use of these fuels by rural households are still inadequately understood. For instance, there is a gap in knowledge regarding how household characteristics and wealth endowment influence household use of fire wood and other energy sources. This study examined household’s domestic energy sources in Wudil town. The aim of this study is to identify and assess household domestic energy sources, through the following objectives:

i. To determine the socio-economic characteristics of the households.

ii. To identify the sources of energy used by the households.

iii. To determine the factors that influences households energy used.

iv. To give recommendation based on the findings.

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The Study Area Wudil Local Government Area is located on latitude 110 35’ to 110 55’ N and 80 45’ to 90 00 E of the Green Which Meridian. The 2006 population census puts the population of the area at 85,189, with an estimated land mass area of 458km2 ( Kano State Population Census, 2006). The climate is the tropical wet and dry climate coded as Aw in the Koppen’s classification with the mean annual rainfall of 850mm usually from May to September and a mean annual temperature of 260 C. The natural vegetation types of the area is characterized by having moderately tall grasses and scattered trees. However, the level of human activities in the area makes it difficult to claim the existence of natural vegetation. In term of morphology, Wudil town is characteristics by an old town (Cikin Gari), New town (Sabon Gari), and Government residential Area (GRA). The old town indicates the areas where the first inhabitants of the area settled which is very close to the River valley on the western part. It is divided into four wards namely; Dafawa (Hausawa), Zango, Unguwar Danya, and Kofar Yamma. This area is peopled by Hausa and Fulani who are Muslims by religion. The new town is a reflection of the expanding nature of the old town over the years due to a combination of factors such as its nodal location, presence of water for domestic and agricultural purpose, presence of public and private institution, etc, which attracted an in flux of people into the town (Dambazau, 2008). Government Residential Area on the other hand, consist of specific areas designed for residential occupation for public servants. They include the local government staff quarters, Shagari quarters, Police quarters, the University quarters, and the Wudil Comprehensive Hospital quarters (Dambazau, 2008). This division may be relevant to energy use, considering the continuing dependence on wood by the majority of households, and present

rates of population growth, an increase in total demand may be expected.

MATERIALS AND METHODS The study was based on primary data sources which were collected using a structured interview scheduled with the household’s head. The household sample was stratified into three residential zones, based on the observed general socio-economic backgrounds of the households. The size of the sub-sample varied in accordance with their respective population such that 30, 30, and 20 samples were selected from Cikin Gari, Sabon Gari, and GRA area respectively. Within each area, respondents were drawn using simple random sampling technique. A preliminary reconnaissance survey of the study area was conducted by the researcher, it involves observation of the places where wood are sold, and hence the pictures of the places were taken. The data collected was compiled and summarized using descriptive statistics presented with the use of tables (as frequencies and percentages).

RESULTS AND DISCUSSION Socio-Economic Characteristics of the Households Table 1 shows the literacy level of the household’s heads. Thus, 72% of the household heads have post-secondary education, 18% have secondary education, and only 5% constitutes households where the head has primary and informal education. There is higher incidence of households with post-secondary education in GRA (90%) than Cikin Gari and Sabon Gari which account for 65%, and 66% respectively. This is largely because households of GRA are mostly civil servants with a high educational qualification. This variation in literacy level does not correlate with the wood consumption, as all the respondents in the three areas used wood as their predominant source of energy.

Table 1: Educational Background of the Household Head.

Educational level

LOCATIONS Cikin Gari Sabon Gari GRA Total %

No. % No. % No. %

Informal 2 7 2 7 0 0 4 5 Primary 2 7 1 3 1 5 4 5 Secondary 6 20 7 24 1 5 14 18 Post-Secondary 20 66 20 66 18 90 58 72 Total 30 100 30 100 20 100 80 100

Source: Field Work, 2008. Table 2 shows that 67% of the household

head are employed in a public sector, whole 33% are self employed for the whole areas. However, variation exists in the public employment sector within Cikin Gari, Sabon Gari, and GRA, accounting for 63%, 67%, and 75% respectively. Thus, households of GRA constitutes a greater portion in the public sector (75%) in which the

reverse is the case in Cikin Gari area where households constitutes a greater portion in the self employed sector (37%) among the three areas. It was found out that occupational category of the households does not affects wood consumption as every household use wood as their main source of energy.

71


Table 2: Respondent’s Occupation Occupation

LOCATIONS Total

%

Cikin Gari Sabon Gari GRA

No. % No. % No. % Public Employment

19 63 20 67 15 75 54 67

Self-Employed 11 37 10 33 5 25 26 33 Total 30 100 30 100 20 100 80 100 Source: Field Work, 2008.

Although all households use fuel wood, the relative position of it and other sources is shown in Table 3. The traditional wood fuels of rural areas are fire wood, charcoal and cornstalks, while the modern energy are kerosene, electricity, and gas. Table 4 indicates that out of 201 responses, 40% 0f the households still depend on wood, this is followed by kerosene accounting for 27% and electricity (16%). The positive response on electricity (16%) is due to the fact that many households in the GRA area and Sabon Gari area owned personal generators for use due to the fact that, gas is very expensive for both the GRA and non-GRA

households, simply because gas is still not within the purchasing power of both the public and self-employed housedhold’s economy. The small proportion of cornstalks (4%) and charcoal (6%) users in GRA is related to social status, largely influenced by their literacy level. The high demand on wood could be attributed to three main reasons, namely; the usual scarcity of kerosene and gas, the high cost and inaccessibility of gas, and the discouragingly long queens for kerosene and increased demand on special occasions such as child’s birth, marriage ceremonies or religious festivals.

Table 3: Household Relative Source of Energy.

ENERGY USED LOCATIONS Total

%

Cikin Gari Sabon Gari GRA No. % No. % No. %

Wood 31 44 32 39 17 34 80 40 Kerosene 19 27 21 26 15 30 55 27 Charcoal 6 9 8 10 3 6 17 8 Cornstalk 3 4 4 5 2 4 9 5 Electricity 9 13 15 19 8 16 32 16 Gas 2 3 1 1 5 10 8 4 Total 70 100 81 100 50 100 201 100

Source: Field Work, 2008. Table 4 illustrates the purpose for which

fuel is used in the area. The table shows that with respects to cooking, wood, kerosene, and electricity play a major role accounting for 43%, 315, and 13% respectively. Wood represents the most widely accessible fuel, technologically, socially, and economically. It is thus the most widely used of all the cooking fuels. The gas on the other hand, is the reverse of wood profile in cooking. The reasons are; certain dishes have to be prepared over a wood fire, and the poverty level which makes gas unaffordable to many household consumers in the low income areas and even in the GRA households. The economic inaccessibility of kerosene to some household’s heads due a periodic scarcity facilitates the emergence of charcoal as a substitute of both wood and kerosene particularly for the Cikin Garo and Sabom gari areas. Its overall function for cooking is negligible in the GRA area.

With regards to heating, wood is still the most readily available energy being used accounting for 34%, this is followed by charcoal (21%), and kerosene (21%). This is because household’s burn wood and charcoal using kerosene to provide warmth against the harmattan chill, and also it is due to lack of modern equipments for heating in the low

income area. With respects to lighting, the dominant energy source for this purpose is kerosene accounting for 50%, largely because of the lack of power supply in the area. However, a significant percentage (29%) of electricity consumption is reported in the analysis. This is due to the use of privately generated electricity in response to the legendary unreliable of the PHCN supply. Self generated power has almost replaced publicly supplied electricity by the households particularly in the GRA area. The intensity of fuel wood consumption in the studied household is illustrated in Table 5. Consumption of wood and demand varies daily, weekly, monthly, and even between seasons as shown in the table. Analysis shows that more wood is used daily in Cikin Gari and Sabon Gari locations accounting for 60% and 73% respectively. However, wood used each day in GRA area depends on the number and types of meals cooked and as such more wood is used at week-ends when more people (e.g guests) are around. Thus, 45% used wood weekly in the GRA, while only 20% uses it daily. Similarly, 35% uses wood on monthly bases. Seasonally, More wood is used in the dry and cool seasons, when in addition to cooking, it is used for heating and for boiling water for bathing.

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Table 4: Purpose of Fuel Used. ENERGY USED

LOCATIONS Total

%

Cooking Heating Lighting No. % No. % No. %

Wood 74 43 19 34 9 17 102 36 Kerosene 54 31 12 21 26 50 92 33 Charcoal 9 5 12 21 0 0 21 8 Cornstalk 7 4 7 13 2 4 16 6 Electricity 22 13 6 11 15 29 43 15 Gas 7 4 0 0 0 0 7 2 Total 173 100 56 100 52 100 281 100

Source: Field Work, 2008.

Table 5: Household Intensity of Fuelwood Consumption.

INTENSITY LOCATIONS Cikin Gari Sabon Gari GRA No. % No. % No. % Total % Daily 18 60 22 73 4 20 44 55.0 Weekly 7 23 6 20 9 45 22 27.5 Monthly 5 17 2 7 7 35 14 17.5 Total 30 100 30 100 20 100 80 100


Observation made at the study area with the help of research assistants shows the intensity of wood consumption, where wood is being sold daily to households on a regular purchase with

no interval. Plate 1 shows the wood market while Plate 2 shows the means of transporting fuel wood in the area.

Plate 1: Showing the market of firewood at the study area Source: Field Work, 2008.

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Plate 2: showing the means of transporting firewood. Source: Field Work, 2008. The demographic variable in table 6 investigated household size. The result shows that proportion if fire wood users rise with increasing size. This is simply because the preparation of meals for large family can not conveniently be used on gas or kerosene stove which most household can not afford. In both the three sampled-areas, household with above 15 family constitutes a greater percentage of use of wood accounting for 40%, followed by 11-15 size, 6-10, size, and household with less than 6 family accounting for 27%, 22%, and 11% respectively. With regards to kerosene however, the reverse is the case where

household with less than 6 families and 6-10 family constitutes a greater percentage of the use of kerosene accounting for 355 and 27% respectively. Similarly households with less than 6 families constitute a greater percentage of the use of gas accounting for 87.5%. The reasons are kerosene tends to be scarce periodically and this makes the price to rise, while gas on the other hand is inaccessible and not within the purchasing power of many households due to high poverty level, also certain dishes can not conveniently be prepared with gas.

Table 6: Energy Used by Household Size. HOUSEHOLD SIZE

LOCATIONS Total

%

Firewood Charcoal Kerosene Gas Electricity No. % No. % No. % No. % No. %

<6 9 11 00 00 19 35 7 87.5 13 40 48 25 6-10 18 22 4 24 15 27 1 12.5 8 25 46 24 11-15 21 27 7 41 11 20 0 0 7 21 46 24 15- Above 32 40 6 35 10 18 0 0 4 13 52 27 Total 80 100 17 100 55 100 8 100 32 100 192 100 Source: Field Work, 2008. Table 7 shows the monthly expenditures of households on fire wood only. The analysis revealed that a smaller percentage of the households spend less than N2,000 on firewood monthly accounting for 17.5%, where as households spending N2,000 to N4,000 on fire wood monthly constitutes a greater percentage, accounting for 46.25% followed by expenditure of N4,000 and more accounting for 36.255. This is to say that, wood constitutes a significant percentage of the household total expenditures when compared with their total monthly income. Table 7: Monthly Expenditures on Fuel wood by Household. EXPENDITURES

LOCATIONS %

Cikin Gari Sabon Gari GRA Total No. % No. % No. %

<2,000 6 20 5 17 3 15 14 17.5 2,000-4,000 15 50 12 40 10 50 37 46.25 4,000-above 9 30 13 43 7 35 29 36.25 Total 30 100 30 100 20 100 80 100


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CONCLUSION AND RECOMMENDATIONS The paper has examined the household domestic energy sources in Wudil town. The results of the study show that fuel wood is the most dominant type of energy used by the households. It constitutes (100%) of all households interviewed. Thus wood represents the most widely accessible fuel for all use in the study area accounting for 36%, followed by kerosene accounting for 33%, and others 31%. More importantly, it appears that household with large families use more wood than households with smaller family size. The study also found strong evidence that monthly income and education of the households do not affect wood consumption. The reasons are; high cost and inaccessible of gas, periodic scarcity of kerosene, and above all high poverty level among the households in the area. However, a significant percentage (20%) of electricity

consumption is reported in the analysis, as a result of privately generated electricity in response to the unreliability of the PHCH supply, where self generated has almost replaced publicly supplied electricity by the households particularly in the GRA area. Based on the findings, the study recommends the following:

• There is need for a wider supply of affordable alternative fuels such as gas to households.

• Kerosene should be made available at a cheaper price.

• Electricity supply should be improved. • Government should implement policy

aimed at improving the living standard of people.

REFERENCES Dambazau, A.M (2008), The Geography of Wudil

Local Government Area. In: Olofin et-al (ed) Wudil Within Kano Region, A Geographic Synthesis. Pp. 113-133, a publication of the Department of Geography, KUST Wudil. Adamu Joji Publishers, Sabon Titi, Kano City, Kano.

FAO, (2004), Forestry Outlook for Africa (FAO). ‘‘Tehad’’, In: FAO Forestry. Paper 144, CD ROM, FAO 2004.

J. A. Falola, R. Cline-cole, H.A.C. Main, Michael Mortimore, J.E. Nichol, S. Patrick, and F.D.O Reilly, (1984), Rural Energy Research Project, Paper presented at the Annual conference of the Nigerian Geographical Association at University of Nigeria, Nsukka, 25th March, 1984.

International Energy Agency (2002, World Energy Outlook, chapter 13: Energy and poverty,

www.worldenergyoutlook.org/weo/pubs/2002/energypoverty.pdf.

Kerekezi and Majoro (2002), ‘‘The Power sector in Africa and Prospects for Introducing Integrated Resource Planning and Demand-Side Management Measures’’, Working Paper No. 8 afreprend/find, Nairobi, 2002.

Spalding Fetcher et-al (2005) sited In: Abebew, D (2008) ‘‘Households Determinants of Fuelwood Choice in Urban Ethiopia: a case study of Jimma Town’’. Journal of Developing Areas, the finarticles.com 18th Nov, 2008. Http://finnarticles.com/p/articles/mi-qa5501/is-200710/ai-n21302745.

United Nations Development Program and World Bank (UNDP and World Bank), ‘‘Household Fuel Used and Fuel Switching in Guatemala’’, Unpublished Manuscript, June, 2004.

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THE IMPACT OF RURAL-URBAN MIGRATION ON THE ECONOMY OF RURAL AREAS IN WUDIL LOCAL GOVERNMENT AREA OF

KANO STATE NIGERIA

Adamu Mustapha Department of Geography, Kano University of Science andTechnology, Wudil

P.M.B 3244, Kano State e-mail address: [email protected]

ABSTRACT This study has examined the spatial pattern of migration and the resultant mass exodus of rural dwellers to urban centers in Wudil local government area of Kano State. The study was carried out through in-depth interview, observation and administration of questionnaire. The consequences of depopulation of our rural areas are the result of urbanization. The study unravels the factors that constantly influence rural dwellers to migrate from their rural base to urban parts of cosmopolitan society. This study discovered that these factors otherwise known as push factors’( such as non availability of profitable employment, lack of basic amenities e.t.c) induce rural dwellers to migrate to other parts of the country.The Study suggests that there is the need for a total re-orientation and awakening of rural dwellers and the society at large on the understanding of the importance of rural resources and how they can be utilized and explored to meet their optimal benefit.

Key words: Migration, rural areas, urban centers, economy

INTRODUCTION kinds of migration in Nigeria include: Rural-rural, rural-urban, urban-rural migrations as documented by Adepoju, (1974). However, large proportions of the population and of the poor are located in the rural areas where the inhabitants do not have ready access to social amenities and capital. Over the years, the living standard of the rural poor has stagnated and in some cases, considerably deteriorated (Mabogunje, 1970). Rapid population growth, the pressure on the land, the prevailing land tenure system, difficult access to land, and declining productivity in combination, resulted in rural poverty and in some cases influenced the incidence and rate of rural-urban areas. Indeed, widespread under-employment has been associated with poverty and has, in turn stimulated migration away from the rural areas.

The rural areas are confronted with many push factors or problems among which are prevailing harsh economic condition such as unemployment, social factors such as lack of infrastructural facilities, good roads, stable electricity and portable drinking water among other things. On the other hand, there are some attractive factors in the urban areas, pull factors that encourage migration from rural areas.These include the availability of profitable employment, basic amenities e.t.c. The intensive and effective utilization of resources in urban areas have made clear differences between urban and rural areas

The main aim of this study is to assess the impact of rural-urban migration on the economy of the rural environment of Kano state. The specific objectives are - a. To identify the people involved in rural urban migration.

b. To determine the magnitude and direction of such migration. c. To examine the push and pull factors responsible for attracting migrants. d. To examine the consequences of the rural-urban migration in the rural area e. To proffer a suitable recommendation to policy makers for tackling the phenomenon.

The Study area Wudil local government area extends for about 4,058sqkm, has a population of about 185,189 (2006 census), is among the present 44 local goverment areas in Kano State. It is located between latitudes 110551 and 120001 North and longitude 80451 and 90001 East. The study area is underlain by Basement complex rocks, which have been subjected to deep chemical and physical weathering to produces regolith and laterization. The rocks are of Precambrian in origin and consist of metamorphic and igneous types which have been in existence for several million years (Olofin,1987). The study area falls under the landform region of Nigeria known as the high plains of Hausaland (Olofin, 1987). The plains constitute the largest of landforms units occupying about 40% of the Kano region. The elevation ranges between 450m – 700m. There also is an additional wind-drift material on the plains especially around the old Utai road in southern part of the area. The present climate of the region is the tropical wet and dry type coded as Aw by Koppens climatic classification. In a normal year the mean annual rainfall in and around the study area is about 800mm – 1000mm.

Temperature is warm or hot throughout the year, even though there is slight cool period between

November to February. December is considered the coolest month with mean values ranging

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between 120C – 210C while April and May are the hottest months with mean average of 350C. Temporal variation of temperature from one year to the other is very marginal. Actual evapotranspiration is estimated to be about 60% of the rainfall in the southern part of the region increasing to about 75% in the north. Relative humidity increases by 2% in the south ward and decrease by the same value north ward (Olofin, 1987). Generally, land in the study area is extensively used for both agricultural and settlement purposes. The study area is extensively cropped; the crops commonly grown in the area include both cash and food crops example includes sorghum, millet, beans, sugarcane, tomatoes, pepper, rice, wheat etc and mango, guava, carrot, cabbage among other things. Agriculture in the area employs more than 70% of the total population, and about 60% of the total income is derived from agriculture, Hamza (1981). Consequent upon these, people in the area invest more labour and capital on the farms during the rainy season. It should also be noted that considerable number of people in the area around the river engage in fishing activities while a small number engage in trading, tailoring, pottery, animal rearing etc.

MATERIALS AND METHODS The research is designed as a survey of the conditions encountered in the study area of the economy of rural dwellers which result to rural-urban migration. The survey was carried out through indepth interview, observation and administration of questionnaire. The sampled framework adopted involved the selection of ten

rural settlements using random sampling techniques. The villages picked were Rege and Gangare in Kausani ward; Dadin Kowa in Lajawa ward; Fagen Zaki in Darki ward; Bange in Achika ward; Bagga-Fulani in Utai ward; Tashar Kubewa in Dagumawa ward; Fadan in Indabo ward; and Gware and Geza in Dankaza ward. Five copies of the research questionnaire were administered in each of the ten settlements making the total number of 50 respondents. The questionnaire was administered randomly by collecting the names of the family head in each village and assigning numbers to them. The numbers were written on pieces of paper and folded into balls. Subsequently, the required number was picked by a person in each village. The questionnaire was designed in two parts, the first part contained questions in general information relating to the respondent that is Bio-data (A. profile of the respondants) while the second part was designed for other aspects of the survey (B.migration characteristics).

RESULTS AND DISCUSSION The results presented here are based on the anlysis of the information provided by the respondents.The results are presented and illustrated with tables and diagrams.

A. Profile of Respondents Age distribution of respondents Table 1 shows that respondents of age group 56 years and above constitute the highest 30 perce ntage. followed by age group 45-55 years constituting 26%.However, these age groups are less productive in the rural economy as able bodies.

Table 1: Age Distribution of The Respondents Age group Frequency Percentage of total

15 – 25 years 6 12 26 – 35 years 7 14 36 – 45 years 9 18 46 – 55 years 13 26 56 years and above 15 30 Total 50 100

Source: Author’s Field Work 2008. Respondents of age group 36 – 45 are mostly parents who have a lot of obligations to perform, thus, their commitments towards the rural economy is low. Respondents of age group 26 – 35 forms only 14% which is low due to the migration of the able bodied person; respondents of age group 15 – 25 constitute 12% of the total which means that some are

dependent while the matured ones are too few for the development and upliftment of the rural economy. Table 2 shows that 42% of the respondents are male and 59% are females.Women constitutes the majority becouse men are more migratory than women.

Table 2 : Sex Distribution of Respondents Sex Frequency Percentage of total

Male 21 42 Female 29 58 Total 50 100

Source: Author’s Field Work 2008. Table 3 shows that the population constitutes mainly of married people.These can be linked to the fact that people marry at an early age in the rural areas.

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Table 3 : Marital status of respondents Marital status Frequency Percentage of total Single 9 18 Married 25 50 Divorced 6 12 Widowed 10 20 Total 50 100 Source: Author’s Field Work 2008.

Divorced people constitute the lowest proportion with 12%. These could probably becouse it’s a taboo and sign of irresponsibility to be a single parent. Table 4 shows that farming is the predominant occupation as it accounted for magnificent 72% of the respondents are farmers with traders constituting 16% in the second place. Civil servants and others which include vulcanizer, carpenter and so on constitute 3% and 4% respectively. These can be linked to the fact that the rural economy is characterized by agriculture, which is mostly subsistence and also petty trading which is mostly women affairs and very few civil servants such as night guards (in government establishment).

Table 5 shows that 78% of the people used family labour and 10% hired labourers while 4% and 8% use mechanized and all techniques respectively.

Table 6 shows that the bulk of the respondents have Arabic education which accounted for 32% while 26% have no formal education and 20% have secondary and higher education respectively. It can be deduced from this that formal education is not common among the people which may be due to the fact that majority of the populace use their time in farming rather than going to school which they believe in time consuming. Also it can be linked to religious belief that their wards may deviate from their religionn through western education as the bulk of the respondents are Muslim.

Table 4 : Occupation characteristics of respondents

Occupation Frequency Percentage of total Farmers 36 72 Traders 8 16 Civil servants 4 8 Others 2 4 Total 50 100

Source: Author’s Field Work 2008.

Table 5: Technique of Farming Technique Frequency Percentage of total

Mechanized 2 4 Hired labourers 5 10 Family labour 39 78 All of the above 4 8 Total 50 100


Table 6: Education status of respondent Education status Frequency Percentage of total

No formal education 13 26 Arabic 16 32 Primary 10 20 Secondary 7 14 Higher education 4 8 Total 50 100


B. MIGRATION CHARACTERISTIC Rate and Gender of Migration Table 7 shows that 96% have at least a member of their family who have migrated while 4% have none of their family member involve in migration at the time of the research. This shows that almost all the respondents had a member or majority had at least a member who has migrated.

Table 7: Family Experience in Migration

Response Frequency Percentage of total Yes 48 96 No 2 4 Total 50 100

Source: Author’s FieldWork 2008.

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Economic Reason

Education Reason

EnvironmentReason

Socialinfrastructure

Table 8 shows that a majority of the migrants are male, probably due to the facts that male assume responsibilities and are more ambitious, which make them determine to travel to find ways to make end meet. Migration is not embarking upon without a reason; the major

influencing factor is spatial differentiation or variation in economic opportunities. The differentiation is resource distribution therefore is determined factor of migration.Figure 9 presents the reasons given for migration in the study area by the respondents

Table 8: Gender of migrants

Gender Frequency Percentage of total Male 32 64 Female 18 36 Total 50 100

Source: Author’s FieldWork 2008.

Fig 1: Reasons for Migration

The figure shows that the main causes of rural-urban migration in the study areas is economic reason which include the search for job opportunity constitutes 64%, with education taking a share of 18% while environment and social infrastructure constitute of 6% and 12% respectively. The main cause of rural migration is traced to be an economic one and it varies from job opportunities present in the urban centers to tradings e.t.c. Education is the second major reason for rural-urban migration. Furthermore, there are also factors like the social infrastructure which is very lacking or better still inadequate Lastly, 21.60 that attributed migrants to environment factors did so because rural areas are known to be experiencing disease out break such as cholera, guinea-worm and so on. The figure shows that the main cause of rural migration is traced to be an economic one and it varies from job oportunities present in the urban centre to trading etc. Education is the second major reason for rural urban migration. Furthermore, there are also factors like the social infrastructure which is lacking and inadequate in the study area. People tend to move to urban centres where all these believed to be guaranteed. Lastly 21.6% attributed migrantion environmental factors did so because rural areas are known to be experiencing outbreak of diseases such as chollera, guineaworm and so on. Therefore, no single reason can be said to

induce an individual to migrate from rural to urban centers, but the most important is due to the economy.

Destination of Migrations Table 9 reflects some urban centers which are known to be of interest or rather interest to the migrants from rural areas because of the nature of their development as reported by the respondents. The table shows that Lagos has the highest number of migrants from the study area probably because of its economic and infrastructural development over other places. It has larger number of industrial development, sea port, airport of international standard, as well as qualitative educational institution. Also the availability of numerous petty trading such as shoe shining,nail cutting is another factor that has catalyzed the influx of people from the study area to Lagos. Kano is the second highest population gainer from the study area which can be linked to its proximity to the area. As a state capital it also offers employment opportunity for its indigenes in the public sector. Age Structure of Migrants Table 10 shows that 70% of the respondents reported that the migrants fall within the age group 18-35 and those within the age group of 15- 17 years are confirned by the respondents to costitutes 18% while those in the age group 35-55 and 55 years and above are mentioned by 8% and 4% of the respondents respectively.

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Table 9: Reported Destination of Migrants Destination Frequency Percentage of total

Kano 7 14 Kaduna 2 4 Abuja 1 2 Ibadan 3 6 Onitsha 1 2 Lagos 35 70 Others 1 2 Total 50 100


Table 10: Reported Age Distribution of migrants

Age group Frequency Percentage of total

15 – 17 years 9 18 18 – 35 years 35 70 35 – 55 years 4 8 55 years and above 2 4 Total 50 100

Source: Author’s Field 2008.

The table implies that the migrants within age group 18 – 35 are highest probably because they are still active and can undertake the risk of migration. However, they form the productive population of the urban areas. The ageing constitute the least migrant age as they are less productive.

Impact of the Migrants in the Source Area

Table 11 shows that only 28% of the respondents believed that the migrants made positive contributions to the development of the area while 72% of the respondents believe they do not.This result implies that a majority of the migrated population do not even bother to contribute to the development of their place of origin which is the study area.

Table 11: Respondents view on contribution made by the migrants to the development of the study area Response Frequency Percentage of total

Yes 14 28 No 36 72 Total 50 100

Source: Author’s Field 2008.

This implies that the effects of migration on the economy of the rural area are largely negative and include loss of labour on the farmland as well as a sharp decline in socio-economic activities as low market turn out. Limited positive

effects include fair utilization of little resources (Fig.3). Neutral in the figure means no positive or negative effects on the economy of the study area.

Negative

Positive

Neutral

FIG.2: Respondents View on Migration Impact

Thus 86% of the respondents affirm that migration has a tremendous and immense negative effects on the economy of their area . However, 6% holds the view that there is a positive effect while 8% is of the opinion that it does not have any effect at all.

CONCLUSION AND RECOMMENDATIONS It is very clear that the poor economic condition and productive system of the villages as well as the poverty striken population are all implications of the unfortunate phenomenon of rural-urban migration, which is persistent in the area.

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However, to curtail and control rural-urban migration, policies and their implementation have to be made. It is no doubt that rural economy depends on agriculture. Government should encourage mechanized and plantation agriculture within the rural areas to improve the economy of the rural areas and encourage the inhabitants to stay home and work. This will also serve as employment opportunity for the population and as well boost the commercial activities of the area. Another major step which could discourage rural-urban migration in the country is siting and establishing small-scale industries (cottage

industries) in the rural areas, this will go along away in solving the problem of unemployment. Apart from the provision of job opportunities, some essential services should also be provided in the rural areas. Such amenities include good transport facility, health, water and stable electricity.

Finally, there should be constitutional provision for siting and decentralizing government headquarters and government parastatals, especially educational institutions to the rural areas so as to achieve even development. After all, today urban centre were once rural communities.

REFERENCES Adepoju, A. (1974). Rural Migration and

Development in Nigeria, Ile-ife University of Ife, Department of Demographic and Social Statistics.

Adepoju, A. (1976). Internal Migration in Nigeria. Institute of Population and Man Power Studies University of Ife, Ile-Ife

Adepoju, A (1977). “Migration and Development in Tropic Africa Affairs.” The Journal of the Royal African Society. Vol. 74 No. 303.

Ajahi, G.M (1990). “Basic Needs and the Urban Poor the Provision of Commercial Services.” Reading in Social Development, DADA Press, Ilorin, Nigeria, pg. 28.

Ayodele, S. (1995).“Political Economy.” Unpublished Post-Graduate Study Paper Presented to DAOPA Students 1995. University of Ile Ife.

Haggerstran, T. (1975). Immigration and Area Survey of Sample of Swedish Migration Field and Hypothetical Consideration of their Gensis. Lumy Studies.

Hamza, S. (1981). “Problem of Rural Urban Migration.” Community Development Bulletin, 12, 3, 1961

Lee, E. (1996). “A Theory of Migration.” Demographic, 3 pp. 47-57

Mabogunje, A.H (1970). “System Approach to theory of Rural-Urban Migration.”Geographical Analysis.

Olofin, E.A (1987). Some Aspects of the Physical Geography of the Kano Region and Related Human Responses. Department of Geography, Bayero University, Kano.

Revestein, E.G. (1889). “The Laws of Migration” Journal of the Royal Statistics Society, 1889.

Sartah, A. (1970). Rural Development Learning from China. Macmillan Press

Tadoro, M.P, (1959). Internal Migration of Developing Countries International Labour Organization, 1959

Wills, K.G (1974). Problems in Migration Analysis. London Saxson House.

Zalinsky, W. (1971). The Hypothesis of Mobility. Transition Geographical Review.

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SPATIAL DISTRIBUTION AND IMPLICATIONS OF GROUNDWATER UTILISATION IN DALA LOCAL GOVERNMENT

AREA 0F KANO STATE

Ismaila Ibrahim Yakudima Geography Department, College of Arts, Science and Remedial Studies Kano

ABSTRACT

This paper examines the spatial distribution of boreholes and their contribution in the area of potable water supply in Dala Local Government. It also quantifies and compares groundwater resources of the area with current withdrawal rate. To collect data field observation, interview and review of relevant documents were conducted. The study shows that there are 436 boreholes in the area which are of different types, and only 35 or 8% were not operational throughout the period of the study. Annual groundwater production through boreholes was estimated at 2.3 Mm3. More than 75% of the groundwater production is delivered through commercial boreholes (public and private). Dynamic and static water resources of the area were calculated as 2.3Mm3/a and 24.3Mm3 respectively. Comparison between current withdrawal rate and that of recharge shows that as much as 99% of the annual recharge is abstracted. If this trend of production level is not checked and more boreholes drilled, the area will have its groundwater withdrawn faster than it is being recharged. However, the supply is being reduced and will one day be gone. In view of this a number of management practices are suggested which include conjunctive surface and groundwater use, strict control of indiscriminate drilling of boreholes, rainwater harvesting and periodic groundwater monitoring in the area.

Key words: Groundwater, Groundwater Utilisation, Dynamic groundwater resource, Static groundwater resource

INTRODUCTION Water is the basis of life on earth and the foundation of all civilizations. Long before early civilization flourished, our stone age ancestors lived in caves and other camps that were close to sources of drinking water, such as springs and lakes (Cech, 2005). Nowadays water is often required in a number of human endeavours for growth and sustainability. It is needed for domestic, agricultural and industrial purpose.

In Nigeria, as in many other developing countries, potable water supply is increasingly becoming a scarce commodity. Many urban and rural communities are finding it increasingly difficult to get adequate quantities of water of acceptable quality for domestic, industrial and other uses. The reasons for this are population growth, urbanisation, rapid industrialization, need for improvement in health care delivery system and other uses which all demand huge quantities of treated water. However, this brings about greater attention to groundwater sources by the general public and water managers. The resource is therefore tapped through dug-up wells and boreholes. Since shallow wells are often bacteriologically contaminated and dry up during the dry season they are usually not consider as a safe source of water and are therefore of minor relevance for water resources planning (Martin and Giesen, 2005).

It is therefore not surprising that government at various levels, International Organization, NGOs, communities and individuals have embarked on large scale drilling of boreholes in the country. Since 1980, groundwater abstraction through boreholes has

greatly increased in the country. For example the number of boreholes increases from barely few thousands to several thousands. This is very evident as for example in former Kano State (now Kano and Jigawa States), KNARDA drilled 1733 boreholes between 1983 and 1989 (Wardrop, 1990). In addition many people are continually sinking boreholes in their premises to meet their water needs.

As like in many other parts of Kano State groundwater is extensively exploited in Dala Local Government area for domestic consumption. The obvious reasons for this may not be unrelated to inadequate and irregular supply of treated water from the municipal treatment plan. But often density of boreholes projects and level of water withdrawal through them in the area was not specified. This study therefore examines the spatial distribution of boreholes in Dala Local Government and assesses the groundwater withdrawal from the schemes. Finally, groundwater withdrawal is compared to resources potential in order to evaluate the sustainability of the current withdrawal rate to draw conclusions about opportunities and limitation for future development.

The Study Area The study was conducted in Dala, one of the Local Government Areas that formed the Kano metropolitan area. The area is located roughly on latitude 12o351N and longitude 8o401E. It occupies an area of about 36Km2 (5.3% of the total land area of Kano metropolis), of which about 75% of the land area is built-up. The climate of the area is the tropical type with alternating wet and dry seasons.

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The mean annual rainfall is about 800mm and occurs for about 4 to 5 months (May to October). The rainfall intensity is very high between the months of July and August (Olofin, 1987). Mean annual temperature recorded for the area is about 26oC, but the mean monthly value range between 21oC, in the coolest months of December to January and 310 C in the hottest months April to May (Ibrahim, 2005). Evapotranspiration is very high with mean annual value of 1772 mm and the daily sunshine duration is about 8 hours (Olofin, 1987). Based on temperature and rainfall conditions, Olofin (1987) observed four distinct seasons in the area. These are: (i) Dry and cool season (Kaka); Dry and hot season (Bazara); (iii) Wet and warm season (Damina); and (iv) Dry and warm season (Rani).

In terms of geology, the area is entirely underlain by basement complex rocks of pre-cambrian origin which comprises of undifferentiated igneous and metamorphic rocks (Olofin, 1989). The hydrogeology of the area is to a large extent controlled by geologic settings, climatic condition, and human activities. As like in other basement complex areas, the area has its groundwater occurrence in fissures as well as weathered overburden. This has consequently given rise to two main types of aquifers which are the weathered zone and fractured zone aquifers. The gently sloppy nature of the surface made the hydrology, largely surface one.

Politically, Dala Local Government consists of 12 wards and traditionally 1 district with 3 villages and 74 smallest wards. The district as a whole unit is administered by a District head (Hakimi). The three major sections of villages are Fuskar Arewa which is headed by a wakili (the Emir’s representative), Gobirawa and Yammata, each of which is headed by village head (Dagaci). The smallest units are normally administered by ward head (mai unguwa). These smallest units or wards mostly formed according to family, ethic or occupational affiliations and many of them bear names that clearly indicate this affinity. The population figure of the area as at 2006 stood at 418,777 (19.4% of the six local government total that formed the larger part of Kano metropolis) (Federal Republic of Nig. 2007).

Going by the figure, the area has a density of about 11,633 persons per Km2.

MATERIALS AND METHOD The study started during the dry season and was completed during the wet season (between April and July 2008). The choice of this period was deliberate. During the dry period the schemes are excessively used due to the limited sources of water, but are lightly used in the rainy period because of the relatively plentiful sources (shallow wells, rain water, and improved supply through public means).

The data used were generated through both primary and secondary sources. The primary sources include field observation and interview. A total of 80 boreholes were randomly selected as sample. This figure was arrived at by taken 20% from each of the five types of boreholes (table 1). According to Arlosoroff et al (1987) 20% of any population is adequate to yield a meaningful statistical validity of result. Interview was conducted with borehole owners or caretakers. Those wells that lack caretaker assigned to them, available users and ward head were consulted for relevant information. Vital information like approximate number of users, duration under which the schemes are put in use and the problem associated with the project where applicable were retrieved. This was complemented by detailed field observation by the researcher and three field assistants. The observation involves physical counting of number of the jerry cans and buckets withdrawing water from the observed borehole stations per hour. Each station was visited three times in both dry and wet season and at each time three visits were made (i.e. morning, noon and evening) with the exception of private non-commercial boreholes which were visited ones before the average withdrawal rate was established. The essence for this is to cross-check the information obtained through interview. These two primary sources proved adequate in estimating the withdrawal volume rate. The groundwater potential of the area on the other hand was calculated using data collected from various secondary sources. They include geology, rainfall, boreholes data and map of the area.

Table 1: Sampled Boreholes Boreholes type Number selected

Hand pump 14 Private commercial 13 Private non-commercial 34 Public commercial 14 Public non-commercial 5 Total 80 Source: Field Survey, 2008

An average withdrawal rate of 0.2 litres per second per hand pump was adopted for this study. The remaining classes of boreholes are connected to pipe systems and water is often withdrawn through taps. Private commercial, public commercial and public non-commercial has taps range from 3-6.

82


Average of 4 taps is considered here for each of these boreholes, while 2 taps are adopted for the case of private non-commercial boreholes. And average yield of 0.3 litres per second was taken for each tap. Groundwater abstraction from boreholes was calculated assuming an average daily pumping duration of eight hours for the case of hand pump, private commercial and public commercial boreholes. Four hours on the other hand was regarded as pumping duration for both private non-commercial and public non-commercial respectively. Dynamic Groundwater resources was arrived at using 800 mm as average annual rainfall depth of the area and a run-off co-efficient of 0.08 which corresponds to the average annual rainfall depth of the area as adopted by Garba and Schoeneich (2003). Static groundwater resources were calculated using 0.027 as effective porosity adopted for the entire region by Schoeneich, (2003).

RESULTS AND DISCUSSION Distribution of boreholes A general survey of boreholes distribution is shown in table 2. From this a number of key trends become apparent. First there are 436 boreholes which are very irregularly distributed in the area. The table reflects that Gwammaja ward has the highest number of boreholes (77) representing 17.7% followed by Gobirawa and Yalwa wards which have 76 (17.4%) and 66 (15.1%) boreholes respectively. Madigawa and Bakin Ruwa wards have the lowest number of the scheme which, are 8 or 1.8% and 10 or 2.3%. This irregular distribution may not be unconnected with political, economic, population and accessibility influences. The table further lists types of boreholes and shows that there were five different types. Private non-commercial is the most common type with the largest number of 174 accounting for 39.9% of the total boreholes. Hand pump ranked second in this order. Public non-commercial constitutes the least percentage

of 7.6. The private non-commercial boreholes also have imbalance distribution. This is particularly pronounced in Yalwa and Gwammaja wards where for instances almost 31.6% and 28.2% were found. This picture indicates larger number of higher income earners, who are not satisfied with the level of water supply in the area. As regard to private commercial boreholes, more than 51% is contained in Gobirawa ward. The obvious reason for this is that the area is poorly connected to the public distribution system and not enjoying water from the system besides large population size which calls for high water demand. Kofar Ruwa ward is the second largest in terms of private commercial boreholes, although the larger part of the area is well connected to and get water supply from public main. The investigation discovered that the presence of Kofar Ruwa market which houses a number of public bathrooms which are also heavily supply water vendors is the main reason for this high density. From the general survey made in the area, it is evident that boreholes show an increased trend in their number. For instance the study conducted by Ahmad and Abdulhamid in 1996 shows that Kofar Ruwa has only one borehole while gobirawa has eight. But recent study shows that boreholes increased to 47 in kofar ruwa and Gobirawa presently has 76 boreholes. This trend is very similar to what really happening in many of the developing countries. For example, China, India, Korea, Pakistan, Bangladesh and many more saw an increased in the number of their drilled wells since 1970s (Zaisheng and Hao 2006). According to Todd (2004) this increase may be attributed to a reduction in physical and environmental opportunities to develop additional fresh surface-water supplies. In addition, a growing awareness of the ready availability, the low cost, and high quality of groundwater is a contributing factor.

Table 2: Distribution of Boreholes in Dala Local Government

Ward 1 2 3 4 5 Total Percentage Adakawa 7 0 2 9 0 18 4.1 Bakin Ruwa 5 0 1 4 0 10 2.3 Dala 4 0 3 12 0 19 4.4 Dogon Nama 4 0 4 4 2 14 3.2 Gobirawa 11 37 19 6 3 76 17.4 Gwammaja 8 2 49 10 8 77 17.7 Kabuwaya 7 7 6 7 0 27 6.2 Kantudu 5 0 3 7 0 15 3.4 Kofar Mazugal 12 8 22 12 5 59 13.5 Kofar Ruwa 10 18 9 1 9 47 10.8 Madigawa 3 0 1 2 2 8 1.8 Yalwa 4 0 55 3 4 66 15.1 Total 80 72 174 77 33 436 100 Percentage 18.3 16.5 39.9 17.7 7.6 100 Source: Field Survey, 2008 1. Hand pumps, 2. Private Commercials, 3. Private non-commercials, 4. Public commercials 5. Public non-commercials

83


Functioning and non-functioning boreholes Quite often a large number of boreholes was discovered in the area but this is not what matters. Satisfactory performance of them is the point of concern, as boreholes may break down and remain that way for quite long periods. During this period of down-turn, the community will not realize the intended benefit from the wells. Following the general physical observation made in the area, some proportion of the boreholes are out of order. Result of this finding is presented in Table 3. From the table, it is evident that 401 boreholes, which constitute approximately 92% are in good working order, only 35 boreholes or 8% are not in good service condition throughout the period of the study. This high percentage reflects serious commitment of the stakeholders towards their projects. Variation in the number of functioning boreholes also occurs across the various types. An overwhelming majority of private non-commercial (98.3%) as at the time of study is functioning. This percentage may not be surprising, as the stakeholders belong to higher economic class who requires huge quantities of water regularly for inevitable flushing of the loo, watering of the flowers and washing their cars among other uses. Public non-commercial boreholes, as table 3 reveals, had one third of its total number currently non-functional. The obvious reason for this may be lack of organisational structure like water committee or boreholes care-taker to manage water points and collects charges from

users which would be used to meet maintenance commitments, when need arises. Discussion with ward heads and some scheme users revealed that, some community members consider provision of improved water supplies as a free service that government must provide for its citizens. As such some members resisted to pay charges or contribution, resulting in resentment. And as a result, when the wells developed any problem it takes time before government comes to repair it. For the case of hand pumps, as high as 90% of the projects is satisfactorily functioning. This very high percentage resulted from the concerted effort put up by the benefiting communities to maintain their facilities through the provision of spare parts and hiring of pumps mechanic for the replacement of worn out components. The finding of this study agrees closely with the survey conducted on rural water supply in Rimingado Local Government by Yakudima (2005), and that of Arlosoroff et al. (1987) covering two provinces in Burkina Faso. Results showed that more than 83% of the projects were working satisfactorily. However, the picture is not as rosy in other areas where vast majority of the schemes were found to be out of order. For example, in 1977 U.S. Peace Corps found that only 40% of hand pumps in Sierra Leone were effectively working (Alosoroff et al. 1987).It is important to note that, all the wells that remained out of working throughout this period of study were not used for further analysis.

Table 3: Functioning and non-functioning Boreholes

Boreholes type Functioning Non-Functioning Total Hand pump 72 8 80 Private commercial 63 9 72 Private non-commercial 171 3 174 Public commercial 73 4 77 Public non-commercial 22 11 33 Total 401 35 436 Percentage 92.0 8.0 100

Source: Field Survey, 2008

Groundwater Withdrawal Groundwater is generally a reliable and good quality water source, and with modern technology for drilling and pumping it is widely accessible throughout most part of the world today (villhoth and Giordano, 2007). Its withdrawal for domestic and other uses continues to increase in both urban and rural settings. Groundwater production through boreholes was quantify on the basis of information obtained from stakeholders, water vendors and physical counting of various sizes of containers collecting water hourly at various water points. Estimates annual groundwater production from boreholes of about 2.3 Mm3 was calculated following the procedure described earlier. A more detailed breakdown of sectoral groundwater

production in the area is presented in Table 4. From the table, it can be established that groundwater is widely but variably used across the whole of the area. For example, Gobirawa ward exert the largest abstraction pressure on the resource. Estimate shows that more than 528, 000 m3/a is abstracted in the area representing nearly one quarter of the annual production by the local government. Kofar Mazugal and Kofar Ruwa were ranked second and third by groundwater withdrawal volume, contributing 14.8% and 12.8% of the total volume withdrawn. Madigawa, Bakin Ruwa, and Dogon Nama are the wards with least groundwater production through the projects. They constitute insignificant proportions which are 1.7%, 2.8% and 3.4% respectively.

84


Going by the result presented here it can be discovered that groundwater has been intensely used in Gobirawa ward, this may not be unexpected considering the large number of private commercial boreholes in the area, which draws substantial quantities. Although Gwammaja ward has the largest number of boreholes, it ranked fourth in

groundwater abstraction. This is clearly due to lower density of private and public commercial boreholes. The lower groundwater abstraction in Madigawa, Bakin Ruwa and Dogon Nama wards is due to their limited number of the boreholes. This may be associated with poor planning and narrow streets which prevented movement of drilling rigs into the area.

Table 4: Annual Groundwater Withdrawal Volume by Wards

Wards Cubic meters/year Percentage Adakawa 131,400 5.8 Bakin Ruwa 62,546.4 2.8 Dala 150,321.6 6.6 Dogon Nama 75,586.4 3.4 Gobirawa 528,228.0 23.2 Gwammaja 275,940.0 12.1 Kabuwaya 150,321.6 6.6 Kantudu 90,928.8 3.9 K/mazugal 335,332.8 14.8 K/Ruwa 291,708.0 12.8 Madigawa 39,420.0 1.7 Yalwa 143,488.8 6.3 Total 2,275,322.4 100 Source: Field Survey, 2008

The proportion of groundwater abstracted relative to total volume withdrawn from each borehole category is shown in Table 5. This indicates the magnitude of the contribution that groundwater makes in the area. The table further illustrates the borehole type through which groundwater has intensely developed. It can be seen that commercial boreholes (both private and public) produce 34.56m3 per day or 4.3m3per hour. This finding correlates with that of Oteri,(2003) who noted the average yield of boreholes in Nigerian Basement Complex terrain as less than 5m3per hour. Private non-commercial boreholes produce relatively lesser amount (4.32m3 per day or 0.54m3 per hour) this is due to their lower number of taps as well as pumping duration. The result of withdrawal volume presented here is not in line with that of Mukhtar (2007) who investigated impact of rapid groundwater withdrawal in Rijiyar Lemo districts. He reported that private boreholes discharge between 45m3 to 67m3 per day, while private non-commercial boreholes yield between 18m3 and 23m3 per day. Of course, this is

comparatively high result. The table further portrays that commercial boreholes, combined, contributed more than 75% of the total water abstracted through the scheme. Public non-commercial and hand pumps contribute small percentages of 6.1 and 6.6 respectively. Very high percentage values were obtained in the case of commercial boreholes both private and public. This may be due to the fact that they have longer operation period (because they all have standby generators in case of power failure) and have high number of taps used for water collection besides numerous vendors. Despite their large number (72) and freely accessed all the time, hand pumps supply a much smaller amount of water than motorised boreholes connected with pipe systems. This low level of water production can be explained by the low yield of the pumps, which is 0.72m3/h. This finding is not surprising since the available hand pumps in use are of the India Mark II and Mark III types which have the average yield of 0.7m3/hr, as discovered by Arlosoroff et al (1987).

Table 5: Annual Groundwater Withdrawal Volumes by Boreholes Type Boreholes Cubic meter/borehole/day Cubic meter/year Percentage

Hand pumps 5.76 151,372.8 6.6 Private commercial 34.56 794,707.2 34.9 Private non-commercial 4.32 269,632.8 11.9 Public commercial 34.56 920,851.2 40.5 Public non-commercial 17.28 138,758.4 6.1 Total 2,275,322.4 100

Source: Field survey, 2008

Determination of Groundwater Resources potentials Two major components of groundwater resources in the area were evaluated, which are dynamic and static. The first represents water

deposit which is renewable i.e. flowing from a recharge source (rainfall) to an area of discharge. It can also be define as the rate at which water deposit can be renovated.

85


The second represents water wealth accumulated during long period of time and may served as a reserve from which water can be drawn in periods when water consumption exceeds water

recharge (Garba and Schoeneich, 2005). The results of the calculated dynamic and static groundwater resourcesin the area are presented in Table 6.

Table 6: Summary of the Total Dynamic and Static Groundwater in Dala Local Government

Groundwater resources Volume (m3) Dynamic water resources 2,304,000/a Static water resources 24,300,000 Source: Author’s Computation

The table shows that the dynamic and static water resources are 2.3M3 /a and 24.3Mm3 respectively. This very huge volume is not surprising, because the geological and geophysical investigations within Nigerian Basement Complex terrains showed that the regions contained appreciable quantity of water in them (Faniran and Omorimbola, 1980). It can also be noticed from the table that static water resources is far greater than the dynamic water resources. This suggests that the aquifer is big enough to receive enormous water at the end of the rainy season. There is no doubt that it is this sufficient quantity of groundwater that led to very high performance of the boreholes and the increase in number substantially since 1983. When total static groundwater resource is expressed in per capita term, every of the 418,777 inhabitants has a share of 58.02m3 while total dynamic resource if calculated in per capita term, gives 5.5m3per person. This equals 15.1 litres per person per day. A comparison of groundwater production through boreholes with estimated resource potentials of the area allows determining whether exploitation of groundwater resources occurs on sustainable or unsustainable basis. From table 4 it can be observed that nearly 2.3 Mm3 is expected to be withdrawn annually while the estimated dynamic resource was given as 2.3 Mm3. Thus it appears that the area has a surplus of only 28,677m3 or 1.2% of the estimated dynamic water resource. Consequently, the

volume drawn is considered to be high and unsustainable and generally threatening the resource base from a quantity point of view. This indeed, could be the major reason for the drying up of the majority of open wells just few months after the rainy period, and many of them were abandoned. It is therefore, important to note that if more boreholes were drilled and current withdrawal rate maintained, the area will have its groundwater withdrawn faster than it is being recharged. This trend will definitely lead to a reduction of the water supply and will one day be exhausted. CONCLUSION It can be concluded that groundwater production through boreholes is considered to be high and unsustainable as it accounts for about 99% of the total recharge in the area. Consequently, an increase of groundwater exploitation at this critical situation may bring about the depletion of aquifers leading to operational difficulties of the boreholes. Hence, groundwater in the area will permanently be lost. Realizing the role played by groundwater in meeting potable water requirement in the area, it is therefore essential to take measures against over exploitation. Such measures consist of the reduction of groundwater draft through conjunctive surface and groundwater use, controlling indiscriminate drilling of boreholes, rainwater harvesting and regular groundwater monitoring for periodic reassessment of the resource.

REFERENCES Ahmad A. S. and Abdulhamid A. (1997) ‘‘Water

Vendoring and water crisis in Some kano urban fringes’’. Paper presented at the National Geographic Association (N.G.A.) 40th annual conference on land administration and Development in Nigeria unpublished, (4th – 7th ). Bayero University, Kano.

Arlosoroff, S., Gerhard, T., Devid,G., William,K., Otto,L., and Robert,R. (1987) Community Water Supply: The Hand Pump option, the World Bank Washington DC 1987.

Cech, T. V. (2005) Principle of Water Resources- History, Development, Management and Policy. Second Edition. John Wiley.

Faniran, A. and Omorimbola, E.A.(1980) ‘‘Trend Surface analyses and practicalImplication

of weathering depths in Basement Complex rocks of Nigeria’’. Nigeria Geographical Journal, vol.23 (2) pp 115-126

Federal Republic of Nigeria (2007) Official Gazette

Garba, M.L. and Schoeneich, K. (2005) ‘‘Water Budget for Zamfara State’’. Water Resources, vol. 16 pp 52-58

Ibrahim, A. M. (2005) Surface Water Resource Management Strategies in the Metropolitan Kano- Nigeria. 1st edition, WADEC Kano Nigeria.

Martin, N., and Giesen, N. V. (2005) ‘‘Spatial Distribution of Groundwater Production and Development Potential in the Volta River basin of Ghana and Burkina Faso’’. Water International vol.30(2) pp 239-249

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Mukhtar, J. (2008) The Impact of Rapid Groundwater Withdrawal in Rijiyar lemo District Fagge L.G.A. Kano State. Unpublished M. Sc. Thesis Department of Geography Bayero University Kano.

Olofin, E. A. (1987) Some Aspect of the Physical Geography of Kano Region and Related Human Responses. Departmental Lecture Series No.1

Olofin, E.A. (1989) Human Responses to the Natural Environment in the Kano Region: Kano and Some of her Neighbours. In B.M. Barkindo (ed) Department of History, Bayero University Kano, ABU press Zaria, Nigeria.

Oteri, A.U. (2003) ‘‘Groundwater Resource of Nigeria – A review’’. Waterfront issue 4, October-December pp 19-22

Schoeneich, K. (2004) Water Resources Administration in Nigeria (invited paper). Presented at the Nigerian Mining and Geosciences Society (NMGS) 39th Annual

Conference ‘Itakpe 2003’ Itakpe Kogi State, 2nd to 8th March 2003.

Todd, D.K. (2004) Groundwater Hydrology. 2nd edition John Wiley.

Villholth, K.G. and Giordano M. (2007) Groundwater Use in a Global Perspective – Can it be Managed? International Water Management Institute, Sri Lanka

Wardrop (1990) KNARDA Final Report –Rural Water Supply Project vol.II Wardrop Eng. Inc.

Yakudima, I.I. (2005) An Evaluation of the Performance of Hand Pump-equipped Boreholes as Sources of Rural Water Supply in Rimingado L.G.A. Kano State. Un published M. Sc. Thesis Department of Geography Bayero University Kano.

Zaisheng, H. and Hao, W. (2006) Groundwater Resources in Asia –Problem and Challenges. China Geological Survey and China University of Geoscciences.

87


MIXED CONVECTION FLOW IN A VERTICAL ANNULUS FILLED WITH POROUS MATERIAL HAVING CONSTANT POROSITY

M.L. Kaurangini*and Basant K. Jha** *Department of mathematical sciences, Kano University of Science and Technology, Wudil, Nigeria

** Department of mathematics, Ahmadu Bello University, Zaria, Nigeria

ABSTRACT This work analysed the behaviour of fully developed free and forced convection flow of an incompressible and viscous fluid in a vertical annulus filled with a constant porous material and saturated with the same fluid. The non-Darcian flow model is adopted here for the momentum transfer in the porous domain in which the inertia effect is not taken into consideration. The influence of the porous matrix on the fluid flow, pressure gradient, and shear stress at the duct surfaces is clearly demonstrated for isothermal and isoflux heating of the duct surfaces. In addition, similar criteria for the occurrence of flow reversal are presented.

Keywords: Mixed, Annulus, Material, Isoflux INTRODUCTION Flow through Convective heat transfer in porous medium has been intensively studied over the past two decades. This is because of its wide applications in geothermal energy engineering, ground-water pollution transport, nuclear waste disposal, chemical reactors engineering, insulation of buildings and pipes, storage of grain coal, and so on. A literature survey shows that Darcy (1856) presented the accuracy of these results restricted to specific range of Darcy and Reynolds numbers. Vafai and Tien (1981) have discussed in length the importance of Brickman and Forchheimer terms in the case of forced convention flow over a flat plate and presented the resulting error in heat transfer coefficient when the viscous and inertia terms are negligible. Joshi (1987) considered the fully developed laminar natural convection flows in vertical annuli in which one of the boundaries is isothermal. Verma and Chauhan (1986) have solved unsteady fluid flow through a circular naturally permeable tube surrounded by a porous material. Al-Nimr and Darbich (1995) investigated the transient response of free convective fluid in a concentric tube annulus filled with a porous medium, Oosthuizen, and Paul (1986) have studied steady laminar natural convection in vertical concentric annuli. Vafai (1984) investigated the effects of variable porosity, in the presence of a solid boundary and inertial forces in porous media showing that channeling (velocity showing a maximum near the wall) is observed under these conditions which leads to enhancement of heat transfer in some cases. In addition, White (1991) treats the problem of fully developed laminar flow through a non-porous channel with permeable walls as a classic solution. Akhilesh, Jha, and Singh (2001) obtained solution of mixed convection flow in a

vertical annulus filled with a porous material considering isothermal and isoflux heating at the outer surface of the inner cylinder when the gap between the two cylinders is less, equal and greater than radius of the inner cylinder. Recently Jha [2005] studied free convection flow through an annular porous medium.

In this paper, the influence of the porous material having constant porosity on the mass flow rate, pressure gradient, and shear stress at the duct surfaces is clearly demonstrated for isothermal and isoflux heating of the duct surface. In addition, criteria for the occurrence of flow reversal are presented.

MATHEMATICAL ANALYSIS A steady laminar fully developed free and forced convection flow of an incompressible and viscous fluid is considered in a vertical concentric annulus of infinite length filled with porous material having constant porosity. A pressure gradient is taken along z-axis parallel to the axis of the cylinder and r-axis perpendicular to it. In formulating the problem, the following assumptions are made:

1. The fluid obeys Boussinesq approximation.

2. The velocity of the fluid varies in the axial direction only.

3. The heat transfer takes place by conduction only.

4. The pressure gradient is taken into account.

Under these assumptions, we considered the flow of fluid through a vertical annulus filled with porous material having constant permeability, by heating the inner surface of the outer cylinder isothermally or isoflux. Then, the basic equations are in (1) and its boundary conditions in (2)

88


( )

:are conditionsboundary

0'

'

'

1

'

'

01

'

'''

'

'

'

'

1

'

'

2

2

02

2

=+

=∂∂−−+−

+

dr

dT

rdr

Td

z

pTTg

k

u

dr

du

rdr

udfeff ρ

βγγ

(1)

bk

q

dr

dTorTTu

aTTu

=−===

===

r'at '

''',0'

r'at '',0'

*'2

0

(2)

In order to have the problem in non-dimensional form, the following parameters are defined.

'

,'

0 a

rR

u

uu == ,

f

eff

TT

TTT

γγ

γ =−−

= ,'

10

11

01

, *

2

k

aDa = , 0

2

'

'0

2

3

,Re,u

a

Z

PP

auTagGr

ff ∂∂==∆=

γγβ

CBTdR

=+−== dTA as written becan 1

dR

dTor 1T conditions heatingisoflux and heating isothermal The

-1.C and 0B1,A

heating,isoflux for the while

1C and 1B0,A

heating, isothermal For the

heating.isoflux or isothermal on the depending constants are C and BA, where

===

===

Thus, the velocity and temperature equations are recast in (3) with boundary conditions in (4)

01d

0Re

1d

2

2

2

2

=+

=++−

+

dR

dT

RdR

T

PGrT

Da

u

dR

du

RdR

uγ (3)

λ==+=

===

Rat CBTdR

dTA 0,u

1Rat rT 0. tu (4)

SOLUTIONS

Solving the above equations in (3) utilizing the boundary conditions in (4) we get the Velocity, )(Ru in

(5), temperature, T in (6), Pressure gradient, P in (7), Skin frictions, 1τ in (8), λτ in (9) and critical

values of GRe, GReh1,GReh2 at both walls in (10) and Fluid flow rate, Q in (11) respectively

+

+

=

Da

RKQ

Da

RIQu

γγ 0201

[ ] PDarRLogKGrDa

t ++)(Re 1

(5)

21 )(KT KRLog += (6)

Pressure gradient P using the relation

( ) ∫=−λ

λ1

2 12

1RUdR

is [ ]19181 ReZGZP −=

(7)

89


11121111111 Re)()( DaBGZKQZZIQZ

dR

duR +−== =τ

(8)

λλλτ λλ

111211111 Re)()(

BDaGZKQZZIQZ

dR

duR +−== =

(9)

[ ]221923

181231ReZZZ

ZZhG

−=

30

292ReZ

ZhG =∴

(10)

∫=λ

π1

2 RudRQ

(11) Where the constants are given in the appendix

RESULT AND DISCUSSIONS The velocity distributions of fluid in the channel formed by two coaxial circular cylinders, as a

function of Da and λ are illustrated in fig. 1 (a & b) for GRe (1000, -1000), when the gap between the cylinders is less or equal to the radius of

inner cylinder ( 2≤λ ). Also depicted in fig. 1 (c & d) for GRe = (1000,-1000) when the gap between the cylinders is greater than the radius

of the inner cylinder ( 2>λ ) both for 1=γ . It is

observed that, for both cases of heating the inner surface of the outer cylinder, the velocity of the fluid increases with increase of gap between the cylinders. Comparison of the velocity distribution curves shows that, the velocity is more half way

of the gap between cylinders for isoflux heating for both values of GRe. This is when the gap between the cylinder is less or equal to the radius

of the inner cylinder ( 2≥λ ) while reverse trend occurs when the gap between cylinder is greater

than the radius of the inner cylinder 2>λ . It is also, revealed that, an increase in Darcy number help to enhance the fluid flow for both values of GRe. This can be explained by the fact that for large Darcy number, the permeability of the medium is large and because of it, less resistance is offered by the medium on the flow field. The reverse flow manifested more for isoflux heating when the gap between the cylinders is greater than the radius of the inner cylinder.

(a) Velocity profile when 1=γ , λ ≤ 2 and GRe=1000

Figure 2 (a-d) show the effect of ratio of

viscosities γ

on the velocity filed, when the gap between the cylinder is less or equal to and greater than the radius of the inner cylinder respectively. Comparison of these figures indicated that the velocity profiles have been more influenced by gravitational force g, for isoflux heating when the value of the Darcy number is higher. It is also noted that, for fixed value of Darcy number and gap between the

cylinders, velocity has decreasing tendency with

increase in ratio of viscosities γ

for both cases of heating of the inner surface of the outer cylinder. Physically, an increase in the ratio of viscosities implies that the effective viscosity of the porous medium is greater than the viscosity of fluid. It is clear that from these figures the input of viscous term on the flow behavior is insignificant for small values of Darcy number

.

-1-0.5

00.5

11.5

22.5

33.5

1 1.2 1.4 1.6 1.8 2

R

U

isoDa=0.01 Flxda=0.01isoDa=0.001Flxda=0.001isoDa=0.01 Flxda=0.01isoDa=0.001Flxda=0.001

90


(b) Velocity profile when 1=γ , λ ≤ 2 and GRe=-1000

(c) Velocity profile when 1=γ , λ >2 and GRe=1000

FIGURE 1: (d) Velocity profile when 1=γ , λ > 2 and GRe=-1000

-2

-1

0

1

2

3

4

5

1 1.5 2 2.2 2.4 2.8

R

U

isoDa=0.01 fluxDa=0.01 isoDa=0.001 fluxDa=0.001 isoDa=0.01 fluxDa=0.01 isoDa=0.001 fluxDa=0.001

-3

-2

-1

0

1

2

3

4

1 1.5 2 2.2 2.4 2.8

R

U

isoDa=0.01fluxDa=0.01isoDa=0.001fluxDa=0.001isoDa=0.01fluxDa=0.01isoDa=0.001fluxDa=0.001

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

3

1 1.2 1.4 1.6 1.8 2

R

U

isoDa=0.01fluxDa=0.01isoDa=0.001fluxDa=0.001isoDa=0.01fluxDa=0.01isoDa=0.001fluxDa=0.001

91


(a) Velocity profile when 01.0=α and GRe=1000

(b) Velocity profile when 01.0=α and GRe=-1000

(c) Velocity profile when 001.0=α and GRe=1000

(d) Velocity profile when 001.0=α and GRe=-1000

FIGURE 2 Table 1 presented the numerical values of skin

friction 1τ (outer surface of the inner cylinder) and λτ

(inner surface of the outer cylinder) and

0.6

0.8

1

1.2

1.4

1 1.5 2 2.2 2.4 2.8

R

U

isoga=1.0

fluxga=1.0

isoga=1.5

fluxga=1.5

isoga=2.0

fluxga=2.0

isoga=1.0

fluxga=1.0

isoga=1.5

fluxga=1.5

isoga=2.0

fluxga=2.0

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1 1.2 1.4 1.6 1.8 2

R

U

isoga=1.0

fluxga=1.0

isoga=1.5

fluxga=1.5isoga=2.0

fluxga=2.0

isoga=1.0

fluxga=1.0

isoga=1.5

fluxga=1.5

isoga=2.0

fluxga=2.0

isoga=1.0fluxga=1.0isoga=1.5fluxga=1.5isoga=2.0fluxga=2.0isoga=1.0fluxga=1.0isoga=1.5fluxga=1.5isoga=2.0fluxga=2.0

0

0.2 0.4 0.6 0.8

1

1.2 1.4

1 1.5 2 2.2 2.4 2.8

R

U


-3

-2

-1

0

1

2

3

4

1 1.5 2 2.2 2.4 2.8

R

U

isoga=1.0fluxga=1.0 isoga=1.5fluxga=1.5 isoga=2.0fluxga=2.0 isoga=1.0fluxga=1.0 isoga=1.5fluxga=1.5 isoga=2.0fluxga=2.0

-1.5 -1

-0.5 0

0.5

1

1.5

2

2.5

3

1 1.2 1.4 1.6 1.8 2

R

U

isoga=1.0fluxga=1.0isoga=1.5fluxga=1.5isoga=2.0fluxga=2.0isoga=1.0fluxga=1.0isoga=1.5fluxga=1.5isoga=2.0isoga=2.0

-2

-1

0

1

2

3

4

5

1 1.5 2 2.2 2.4 2.8

R

V


-1

-0.5 0

0.5 1

1.5 2

2.5 3

3.5

1 1.2 1.4 1.6 1.8 2

R

U


92


p (non-dimensional pressure gradient) and mass flux for both values of GRe and isothermal and isoflux heating respectively. The results clearly

indicated that the skin friction 1τ has decreasing

tendency with increase in Darcy number while λτ

has increasing tendency with it. Pressure gradient has decreasing tendency with increase in Darcy number. Physically for small Darcy number, the

porous matrix offers large resistance on the flow field and thus slows down the velocity as well as its gradient. The numerical values of the skin friction are more for isoflux condition than isothermal condition. The mass flux remain constant with increase in Darcy number and increase in the gap between the cylinders for both values of GRe and heating conditions (isothermal and isoflux).

Table 1 : Numerical values of skin Frictions, pressure gradient and mass flux

ISOTHERMAL CASE

ISOFLUX CASE

Da

P M

P M 1.0 0.010 -13.97228 -27.07448 -223.04110 7.03717 1.09356 4.25885 487.04780 7.03717 0.001 24.25317 -39.63361 725.67790 44.41153 -26.44767 1413.85500 1.5 0.010 -9.81581 -21.12134 -221.47340 33.14909 1.57662 498.42840

0.001 20.40167 -32.54791 739.36320 36.61375 -22.04968 1429.35400 2.0 0.010 -7.42014 -17.58346 -220.34130 28.51820 -0.02600 509.09980 0.001 18.11398 -28.32947 751.19570 31.97541 -19.43499 1442.78900 1.0 0.010 -13.82649 -25.57991 -200.56180 9.42478 48.09541 8.57808 553.87450 9.42478 0.001 24.34804 -38.40232 735.60020 46.27924 -24.93417 1472.00500 1.5 0.010 -10.06492 -20.17269 -199.49190 38.67336 5.35260 562.51700 0.001 20.33854 -31.48432 745.46930 38.03705 -20.70674 1483.44000

2.0 0.010 -7.84824 -16.95010 -198.66610 33.12348 3.41013 570.48070 0.001 17.95307 -27.36319 753.94790 33.12962 -18.19056 1493.29000

The numerical values of critical GRe at the outer surface of inner cylinder (GReh1) and at the inner surface of the outer cylinder (GReh2) are presented in Table 2 for some typical values of non-dimensional parameters. It is clear that, GReh1 is inversely proportional to the Darcy

number for Isothermal heating for a fixed λ . Similarly, GReh2 is inversely proportional to the

Darcy number for Isoflux heating for a fixed λ . These show that, Darcy number exert destabilizing influence on the flow formation at outer surface of the inner cylinder for Isothermal heating and at inner surface of the outer cylinder for Isoflux. It is also observed that, the effect of

λ on GReh1 is Darcy number dependent, in case of Isothermal heating for the gap between the

cylinders is less than the radius of the inner cylinder. While GReh2 decrease with increase of

λ for both cases of heating. Likewise, the values of both GReh1and GReh2 decrease, with increase

of λ for Isothermal heating when the gap between the cylinders is greater than the radius of the inner cylinder. It can be concluded that, the occurrence of flow reversal both at the outer surface of inner cylinder and at the inner surface of the outer cylinder can be checked by increasing the gap between the cylinders in both cases of heating and GRe. These critical values of GRe are responsible for the occurrence of flow reversal at the outer surface of the inner cylinder and at the inner surface of the outer cylinder.

Table 2 The values of critical GRe

λ ≤2 λ>2

CASE Da λ Greh1 Greh2 Greh1 Greh2

Isothermal 0.010 1.8 477.8036 -778.2891 481.7277 -880.7513 0.001 1.8 3476.0640 -5185.8810 4059.8920 -7211.6020 0.010 2.0 467.1663 -787.0256 513.9790 -1016.2480 0.001 2.0 3649.2670 -5804.1460 4503.6940 -8771.9420 Isoflux 0.010 1.8 -451.6035 735.6117 -229.2713 419.1808 0.001 1.8 -3285.4560 4901.5130 -1932.2470 3432.2570 0.010 2.0 -336.9892 567.7189 -178.2833 352.5049 0.001 2.0 -2632.3900 4186.8060 -1562.1910 3042.7130

CONLUSION The fully developed flow characteristics including phenomena of flow reversal of the combined free and forced convection in a vertical annulus filled

with porous material having constant porosity are investigated theoretically. It was discussed when the inner surface of the outer cylinder is heated isothermally and isoflux.

1τ λτ 1τ λτ

93


The most important outcome of the numerical calculations is that behavior of the flow formation of the fluid because of mixed convection between the cylinders filled with porous material having constant porosity and saturated with the same fluid can be controlled

by applying a suitable mode of heating process and by changing the gap between the cylinders. The occurrence of the reversal flow is found to be

strongly dependent on the value of Re

Gr=GRe.

REFERENCES Akhilesh K.M.,B.K. Jha and A.K. Singh (2001):

Mixed convection in a vertical annulus filled with a porous matrix, Thermal systems and Heat Transfer (proceeding of third National Conference on thermal systems) TNCT-2001

Al-Arabi M., El-Shaarawi M.A.I. and M. Khamis, (1987) Natural convection in uniformly heated vertical annuli, Int. J. Heat Mass Transfer 30, 1381-1389.

Al-Nimr M.A.,Darabsch T.T(1995). Analytical solution for transient laminar fully developed free convection in open-ended vertical concentric porous annuli.ASME J. Heat Transfer 117, 762-764

Darcy, H. P., (1856)Les fontins publiques de la ville de dijoin, Victor Dalmont , paris

El-shaarawi M.A.I. and Sarhan A., (1981)Developing laminar free convection in an open ended vertical annulus with a rotating inner cylinder, ASME J. Heat Transfer 103,552-558

Jha Basant K. (2005) Free-convection flow

through an annular porous medium”, J.

of heat and mass transfer, Germany, vol.

41, no.8, pp. 675-679.

Joshi H.M. (1987) Fully developed natural convection in an isothermal vertical annular duct. Int. Comm. Heat Mass Transfer 14, 657-664

P.H. Oosthuizen and J.T. Paul, (1986) A numerical study of free convective flow through a vertical annular duct, ASME Paper 86-WA/HT-81.

Singh, A.K. and Thorpe,G.R. ( 1995);Natural convection in a confined fluid overlaying a porous layer – a comparison study of different models, Ind.J.Pure and Appl.Maths. Vol.26, pp.81-95.

Tong, T.W. and Subramaniam,E, (1985):A boundary layer analysis for natural convection in vertical porous enclosures use of the Brinkman-Extended Darcy model,Int.J.Heat and Mass Transfer, Vol.28 pp 563-571,

Vafai, K and Tien, C.L. (1981); Boundary and inertia effect on flow and heat transfer in porous media,Int.J. of Heat and Mass Transfer, Vol.24,pp.195-204,

Vafai, K., (1984) Convective flow and Heat Transfer in variable-porosity media, J. Fluid mechanics, vol. 147, 233-259.

Varma P.D., Chauhan D.S. (1986) Unsteady flow of a viscous incomparable fluid through a circular naturally permeable

APPENDIX

( )

t

t

rK

LogBA

BrCK

=+

−=

2

1 )(λλλ

Da

ZDa

Zγλ

γ== 21 ;

1

)()(

)()(

)()()()(

102010

1042039

201020108

ZKZKZ

ZKZZKZZ

ZIZKZKZIZ

−=−=

−=

( )( )

2

1

14

1

2

)(

2

212

22

11

−=

−−=

λ

λλλ

BZ

LogZ

[ ]tt rLogKDaZDarZ +== )(; 143 λ

94


)()(

)()(

)()()()(

10207

1042036

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ZIZIZ

ZIZZIZZ

ZIZKZIZKZ

−=−=

−=

[ ]

[ ]

( )12

1

)()(

)()(

215

1

11114

1

111113

−=

−=

−=

λ

λ

λ

DaZ

Z

ZKZKZ

Z

ZIZIZ

[ ]

5

761

Re

Z

PDaZZGQ

+−=

[ ]8

1092

Re

Z

PDaZZGQ

+−=

[ ]1211116 ZZBDaZ +=

−+=

+−=

8

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14718

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146

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1491617

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18

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)(

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=

=

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)(

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=

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5

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λ=

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182829

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−−==

95


STUDY OF THE CHANGES IN ABSORPTION SPECTRA OF INDIGO DYE AFTER EXPOSURE TO MERCURY LIGHT

T.S. Bichi1, and T. C. Akpa2 1. Department of Physics, Kano University of Science and Technology, Wudil, Kano State

2 .Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Kaduna State 1Corresponding author; [email protected]

ABSTRACT Samples of natural indigo dye collected directly from a dye pit at Kofar Mata Dyeing Center in Kano City were exposed to mercury light for different intervals of time. Absorbencies of the samples were then measured at wavelengths between 620 nm to 640 nm (indigo dye colors absorb maximally in this region). Regular and consistent increase in absorbance of the dye with increase in exposure time had been observed such that as exposure time increased the absorbance also increased.

Keywords: Absorption, Spectra, Indigo, Mercury INTRODUCTION Right from the time of trans-Saharan trade Kano had been known to be the centre for commerce. Locally dyed clothes were among the trade commodities that attracted people from far and wide to Kurmi market in Kano City. These clothes were exported to neighboring countries and as far as Tripoli in Libya [1]. So there is a lot of economic potential associated to natural indigo dye. It is the only natural dye that is still globally important in the textile industries because it contains several related dye chemicals which give different shades of blue namely light blue, navy blue, blue and dark blue. This cannot be achieved with the synthetic substitute [2]. This work is

aimed at improving the industrial potential of the traditional indigo dyeing system used in Kano. The objectives of the research work are:- i. To obtain a spectrum of the dye in the ultraviolet and visible region, so as to identify the peak corresponding to the required colour. ii. To evaluate the effects of exposing indigo dye sample to mercury light on established spectral peak of the dye. Theory If E

1 and E

2 are the energies of a molecule before

and after absorbing light energy in the ground state and excited state respectively, then the absorbed energy ∆E is given by the expression:

∆E = E2-E

1 = hν =

λhc

[2]

where h = Planck's constant c = speed of light .wavelength of the absorbed light = ג

Lambert’s law of absorption of light states that the proportion of light absorbed by a transparent medium is independent of the intensity of incident light and each successive unit layer of medium absorbs an equal fraction of light passing through it. This is mathematically expressed as: I=Iоe

-αL where Io = intensity of incident light

I = intensity of transmitted light L = Thickness of layer of transmitting medium (cm) and α = absorption coefficient of the medium. INTERACTION MECHANISMS A large number of possible interaction mechanisms for gamma rays in matter are known but three major mechanisms play greater role in interaction of radiation with matter. Photoelectric Absorption In this process a photon undergoes an interaction with an absorber atom in which the incident photon completely looses its energy and

disappears. In its place an energetic photoelectron is ejected by the atom from one of its bound shells. This interaction is with the atom as a whole rather than the free electrons [3]. If the photon carries sufficient amount of energy the photoelectron is most likely to be librated from the most tightly bound K shell of the atom [6]. The ejected electron leaves the absorber atom with kinetic energy given by the expression:-

eE = bEh −υ [4] (2.1)

96


Where hv is the energy of the incident photon and Eb is the binding energy of the librated

photoelectron. Photoelectric process becomes the predominant mode of interaction for incident photons of relatively low energy. It also predominates when the absorber material is of high atomic number Z. In fact the probability of photoelectric absorption per atom can be approximately expressed as:

τ = constant 5.3E

Z n

(2.2)

where n varies between 4 and 5 over the gamma-ray energy region of interest [6]. Compton Scattering This type of interaction process takes place between the incident photon and an electron in the absorbing material which is assumed to be at rest and it is called a recoil electron. In 1922 Compton conducted an experiment in which an incident photon with energy of about 17.4 MeV

was found to be deflected through an angle θ to the original direction of the photon after interaction with a recoil electron. He also discovered that the struck electron recoils at an angle φ as shown in figure 2.1

c mc2 ● (a) Before collision

Scattered photon hv' c θ φ E

1 P

1 ●

Recoil electron (b) After collision Fig 2.1 Diagrammatic Representation of the Compton Process The incident photon initially with energy h v transfers a portion of its energy to the free electron initially at rest with total energy of mc2.

After collision the scattered photon now has reduced energy h v ’given by

hν’ =

)cos1(12

ϑ−+mc

hvhv

(2.3)

where mc2 is the rest-mass energy of the electron, which is 0.511 MeV. It can therefore be seen that for small scattering angle θ very little energy is transferred to the free electron as the scattering target.

Pair Production This is the third interaction mechanism which competes with the other two described above. If the energy of the incident photon is at least twice the electron rest energy (1.02 MeV), then the process of pair production is energetically possible [6]. This incident photon can be converted into an electron-positron pair in the field of an atomic nucleus. Pair production can also occur in the field of an atomic electron but the probability of occurrence is considerably smaller and the threshold energy is 4mc2. In the practical sense therefore the probability of this interaction remains very low until the gamma-ray energy approaches several MeV. So, pair production is predominantly confined to high-energy incident photons. In the interaction (which must take place in the coulomb field of a nucleus) the gamma-ray photon disappears and

is replaced by an electron-positron pair. All the excess energy carried by the incident photon above the 1.02 MeV required to create the pair goes into kinetic energy to be shared by the positron and electron during the annihilation process [5].

These three major types of photon interaction compete with one another, the determining factors being mainly the proton number of the absorbing medium and the energy of the incident photons.

Research problems There is a serious decline in the activities of the textile industries in Nigeria. A current affairs program aired by Radio Kano in May, 2006 pointed out that out of one hundred and seventy (170) textile industries in Nigeria only thirty (30) industries (18%) are functioning.

97


The remaining one hundred and forty (140) industries (82%) are closed down because of one shortcoming or another. It is also disturbing to find out that only forty three (43) out of seventy dye pits at Kofar Mata dyeing centre are functional [7]. So this research work is of paramount importance. MATERIALS AND METHODS Collection of Sample The samples were directly collected from a dye pit at Kofar Mata dyeing centre in Kano city. It was collected in an amber bottle so as to minimize the effect of daylight on the sample [8]. The collection was done 30 cm below the surface of the solution to minimize the effect of air on the sample. It was then taken to the dark room where all the experiments were conducted under amber light. Obtaining the Spectrum of the Dye The indigo dye sample was loaded into the cuvette and the cuvette slotted into the sample compartment of spectrophotometer. Absorbencies of the sample (which automatically appeared on the screen) were recorded at equal

intervals of 20 nm between the wavelengths of 200 nm and 900 nm. Data obtained was plotted to get the spectrum of the dye as on figure 4.1. Absorbencies after exposing the Dye to Mercury Light 5 ml of indigo dye sample were added to each of the four Petri-dishes that were labeled 2 minutes, 4 minutes, 6 minutes and 8 minutes. The samples were exposed to mercury light for times indicated on the label. Absorbencies for the exposed samples were then measured at equal intervals of 5 nm between the wavelength of 620 nm and 640 nm which is the peak region for the indigo dye color. RESULTS AND DISSCUSSIONS Spectrum of the Dye A plot of wavelength versus absorbencies gave the spectrum of the dye as in Figure 4.1. The peak corresponding to colour of the dye appeared between 600 nm and 700 nm.Attention was therefore narrowed down to this region when measuring the absorbencies of the dye after exposure to mercury light.

Fig. 4.1 Total Ultraviolet-Visible Spectrum of Indigo Dye Absorbencies of indigo dye after exposure to mercury light Figure 4.2 shows the absorbencies of the dye after exposure to mercury light for different intervals of time. There is a consistent increase in

absorbance with increase in exposure time such that peak value absorbance after exposure for 2 minutes is lowest (0.73) while it is highest (0.79) after exposure for 8 minutes.

0

0.5

1

1.5

2

2.5

3

200 300 400 500 600 700 800 900

Wavelength (nm)

Ab

sorb

ance

(A

U)

Peak of Interest

Peak of interest

98


Figure 4.2 absorbencies after exposure to mercury light SUMMARY Fig. 4.1shows the ultraviolet-visible spectrum of indigo dye. The peak of interest appears between 600 nm and 700 nm. Further analysis shows that the dye maximally absorbs at 640 nm. Figure 4.2 shows a regular and consistent increase in absorbance with increase in exposure time. This consistent change in absorbance is achieved due to presence of ultraviolet radiation which is emitted by mercury light (at low pressure).Similar change had also been achieved by exposing the natural indigo dye to daylight at 3.00 pm.This change is due the substantial amount of ultraviolet radiation which forms part of solar radiation especially in the late afternoon.

CONCLUSION It had been observed that natural indigo dye absorbs maximally at the wavelength of 640 nm.

This is the wavelength of the blue color of indigo dye. It had also been observed that exposing indigo dye to mercury light affects the absorbance of the dye such that as exposure time increases absorbance also increases. RECOMMENDATION It has been established that exposing indigo dye to mercury light has a direct effect on the absorption pattern of the dye. This effect would have a positive influence on the quality of the clothes that are dyed with natural indigo dye. It is therefore recommended that the local dyers at Kofar mata dyeing centre be encouraged to expose the clothes dyed with indigo dye to mercury light before spreading them out to dry. This might improve the quality of the dyed clothes.

REFERENCES [1] Dan Hausa J. (1996). A Comprehensive

Documentation on Traditional Dyeing (Rini) (Papers compiled by History and Culture Bureau Kano).

[2] Tyagi, O. Yadav, M. (2001). A Textbook on Synthetic Dyes. Anmol Publications Ltd. New Delhi. pp. 304

[3] Alan, M. (1993). An Introduction to Radiation Protection. Chapman and Hall. London. Pp.18-25.

[4] Serway F. (2000). College Physics Fourth Edition Prentice-Hall Upper Saddle River pp. 889-891

[5] James, E.T. (1995). Atoms, Radiation and Radiation Protection. John Willey and Sons Inc. New York pp.169-135.

[6] Glenn, F.K. (2000). Radiation Detection and Measurement John Willey and Sons Inc. Hoboken pp.49-52.

[7] Personal Communication (2006). A discussion held with the Chief of Traditional Dyers (Sarkin Rini) at Kofar Mata Dye Pits Centre in Kano City

[8] Bechtold, T. (2002). Process, Balance and Product Quality in the Production of Natural Indigo from Polygonum Applying Low Technology Methods. Institute of Chemistry and Textile Physics Leopold-Franzen University, Dombirn Pp.171-177.

0.63

0.68

0.73

0.78

0.83

620 630 640 650

Wavelength (nm)

Ab

sorb

ance

(A

U)

unirradiated 2min irr 4min irr 6min irr 8min irr

99


OVERVIEW OF CLIMATIC DATA AVAILABILITY FOR KANO REGION AND SUGGESTIONS FOR COPING WITH CLIMATE

CHANGE IN THE REGION

A. B. NABEGU Kano University of Science and Technology, Wudil

ABSTRACT Coping with and adapting to climate change requires a strong scientific understanding integrated with socio-economic considerations. Currently, international efforts are developing climate change research agendas needed to develop this basic understanding and explore ways to integrate physical and socio economic processes within a modeling framework. The immediate focus is on undertaking regional scale analyses coupled with models suited to the physical and socioeconomic environment. This paper overviews current work relating to climate change in Kano region identifying key issues and provides a concise research framework for further work.

Keywords: Kano region, Climate change, Climate variability, Rainfall variability, Regional assessment models, Local knowledge

INTRODUCTION Climate change is linked to an increase in global carbon dioxide, (CO

2)

concentration in the atmosphere, together with a few other greenhouse gases (GHG). This increase is at least partly the result of the influences of human activities on nature such as exhaust gas emissions from vehicles, coal burning for energy, and deforestation. An increase in the amount of CO

2 leads to increased trapping of solar heat in

the atmosphere, giving rise to a warmer global climate. Of more concern are the indications that even a very small increase in global temperature leads to an increase in extreme weather events such as stronger storms and hurricanes, worse droughts and floods, changes or shifts in seasons, and the spread of disease which have significant implications for soil productivity, water supply, food security, and in turn human welfare and poverty, as well as deleterious and, in many cases, irreversible impacts on biological diversity. Recognizing the issue of potential negative impacts of global climate change, the world meteorological organization (WMO) and the United Nations Environment Programme (UNEP) established the Intergovernmental Panel on Climate Change (IPCC) in 1988. One of the main outputs of the IPCC is a regular five- to six-yearly comprehensive assessment of current knowledge on the science of climate change, its impacts adaptation options, and options to reduce net greenhouse gas emissions: the first assessment report in 1990 was followed by the signing of the UNFCCC in 1992, the second assessment report in 1995 was followed by agreement of the Kyoto Protocol in 1997, and the third assessment report in 2001 was followed by finalization of the Kyoto Protocol rules and widespread ratification of the Protocol in 2002.The fourth assessment report of the IPCC was released in 2007. The IPCC did not suggest a specific level of warming that might need to be avoided, but limited itself to outlining the identified risks for different levels of climate change that could

occur during the 21st century under different emission scenarios (IPCC, 2001a, b, d).For instance, it is anticipated that a given change in climate will result in more adverse socio-economic impacts in developing areas like Kano region than in other parts of the world. This relates to several factors linked to the vulnerability of society and the sensitivity of the environment. Important factors here are high dependency on bio-fuels, high dependency on agriculture and forest sectors, restricted population mobility, poor health facilities, high population growth rates and low material standards. Furthermore, Kano region has a much higher share of its economy dependent on climate-sensitive sectors such as agriculture. Present level of research and knowledge on climate change in Kano region and Nigeria in general is hardly advanced; the current understanding of many critical processes is limited and systems are subject to multiple climatic and non-climatic stresses the interactions of which are not always linear or additive. Thus, much is left to be done in the area of understanding and characterizing the strands of complementary or synergistic relationships between and amongst the various sub-sectors of the economy vulnerable to climate change. These are compelling arguments for internalizing the global consequences of development actions in Kano region that will lead to an integrated adaptation approach that can be operationalized in the field. The aim of this paper is to assess the current level of data and local research pertaining to climate change in Kano region and highlights the fundamental studies that are needed in order to amass the necessary data for adaptation to and mitigating the present and future impacts of climate change.

Study Area Kano Region, (Fig.1) is combined Kano and Jigawa States, located at the eastern margin of the Northwest Geo-Political Zone of Nigeria.

100


The region is located approximately between longitudes 7o 45’ E and 10o 35’ E, and between latitudes 10o 30’ N and 13o 02’ N and as such is a part of the Sudano-Sahelian zone of Nigeria (Olofin, 2008). Kano region has a land area of 43,285 km2 - about 4.69 percent of Nigeria’s total land area (Mustapha and Yakudima, 2008), and is recognized as having a climate that is among the most variable in the world on intra-seasonal to decadal timescales (Nicholson 2000a, 2001; Kowal and Kassim 1975 ; Adefolalu, 1983 ; Farmer and Wigley, 1985; Leow and Ologe 1981; Tanaka et al. 1975; Dennett et al., 1985; Hutchinson, 1985).The size of the region and its amplitude of climate variability make the region an important component of the climate system of surrounding region. Kano region is characterized by a high population growth rate (2.9% in 1992-2006). It has a total population of about 14 million and a population density of 649 people per hectare compared to a national average of 235 and world average of 442. In fact, within the Kano –closed settled zone population density is about 1000 per hectare (see Mortimore, 1958,1962). About half of the region’s cultivable land is arid and semiarid, mostly with entisols which have low organic matter content. About 65 percent of the cropland and 30 percent of the pastureland are affected by degradation with consequent decline in crop yields and chronic food insecurity. It is also estimated that 14 percent of degraded soil result from vegetation removal, 13 percent from over-exploitation, 49 percent from overgrazing and 24 percent from agricultural activities (ECA, 2006). Agriculture is the economic mainstay accounting for up to 70 percent of the source of livelihood of the population and nearly 90 percent of the population work primarily in agriculture (World Bank, 2000). Urban Kano accounts for 37 percent of the total population of the region and the city is undergoing rapid population growth of more than 6.5 percent per year (2006, Census, report) accompanied by rapid development pressures with high demands for housing and infrastructure.

MATERIALS AND METHODS The method employed was essentially an examination of the climate change platform; an audit of current data and research of climate change in the region; overview of the implication of current situation; tentative suggestions as to how to ensure a better preparedness in the face of increasing manifestation of the negative effects of climate change in the region.

RESULTS AND DISCUSSION Climate Data in Kano Region Trends in Kano regions climate: precipitation and temperature Most environmental concerns in Kano region are linked to water and rainfall. Rainfall has attracted the most attention and good databases exist. The

patterns of rainfall variability and controlling processes are generally well understood (Nicholson 2000a, 2001). The climax of the Sahelian Drought in the years 1972 and 1973 provoked a number of analyses which sought to understand the social and economic disaster mainly in terms of rainfall failure (Dalby and Harrison Church, 1973: Davy, 1974). These years were soon found to have immediate antecedents as far back as 1968 and as the seventies proceeded, it became clear that a run of dry years was occurring (Fig. 1) and with each additional dry year the persistence of drought became more noticeable and its statistical significance increase. No dry spell of similar length can be shown from the rainfall records except, possibly, that of the 1860s and 1905-15 when records were scarce (Mason, 1976). The pattern of departures from normal showed that the worst affected area of the country was northern Kano where negative departures exceeded 40 per cent (figure. 1). The significance of these negative departures in the seventies was to depress the five-year running mean for Kano to levels unprecedented since records began (figure 2). The year 1973 was the worst on records; yet it is apparent from an examination of the curve that rainfall failed to recover before plunging again in the eighties – the running mean actually falling still lower as each year from 1982 to 1985 exceeded its predecessor in dryness. Moreover, successive 30-year means fell steadily from 104 per cent of the long-term mean in 1931-60 to 99 in 1941-70 and 97 in 1951-80. In the years 1980-84 Kano received 105, 66, 73, 57 and 55 per cent of its 1931-60 mean rainfall. Leow and Ologe (1981) compared mean rainfall for the double decades 1918-40, 1941-60 and 1961-78 at ten stations in northern Nigeria. They found that north of latitude 110N (where Kano region is} a significant decline occurred in the last of the three double-decades, but that south of this line, the decline was not statistically significant. An elementary analysis of the monthly distribution of rainfall draws attention to several trends which appear rather well established. Table 1 shows that in the 80 years 1906-85 rainfall in the critical growing months of July-September was lower in the two decades 1966-85 than in any previous double decade for every month except June; that expressed as a percentage of the monthly mean, August rainfall in the last double-decade was reduced by more than that of other months, followed closely by September, and June the least; and the greatest percentage reduction in mean rainfall between the 1946-65 and 1966-85 double decades was in August. The experience of 1984 is thus seen to be but an extreme case in the trend that has become established over two decades, confirming what has been reported elsewhere (Tanaka et al. 1975; Dennett et al., 1985).

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Such a trend has the most serious implications for rain-fed agriculture, whose centre rhythm is based on the expected August peak. Late-maturing crops in particular are adversely affected by early termination of the rains. It appears from the data in table 1 that a reduction in total rainfall in the last two decades has not meant simply the substitution of a regime

previously associated of the rainy season. Of five proximate rainfall stations north of Kano, all but one recorded an even greater diminution of the August rainfall in 1966-85 (table 2) than did Kano (table 1). The changing configuration of monthly rainfall distribution can thus be shown from the instrumental record.

Fig. 1. Rainfall departures from the mean in 1973 (per cent) Source: Adapted from Oguntoyinbo and Richards (1978); Derrienic et al. (1976). Fig. 2. Rainfall at Kano, 1906-85 (five year running mean). Averages are shown for 1906-85 (839mm), for 1931-60 (868mm), 1941-70 (836mm) and 1951-80 (813mm) Source: Mortimore (1989)

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Table.1 Monthly distribution of rainfall at Kano (June-September), 1906-85 (adapted from Mortimore,1989) Time period June July August September

1 1906-85 average (mm) 115.3 201.1 294.7 126.9 1 1906-25 102.3 211.2 329.3 139.7 2 1926-45 119.7 197.6 305.3 135.6 3 1946-65 130.8 220.8 313.7 129.2 4 1966-85 108.4 174.9 230.4 103.3 1 1906-85 average (per cent) 100 100 100 100 2 1906-25 88.7 105.0 111.7 110.1 2 1926-45 103.8 98.3 103.6 106.8 3 1946-65 113.4 109.8 106.4 101.8 4 1966-85 94.0 87.0 78.0 81.4 5 Percentage change from period 3 to 4 -17 -21 -27 -20 The increased availability of climate records in public databases has greatly enhanced analysis of rainfall, and efforts to improve data availability should be continued. However in Kano region more recent data are less available. In general the in situ observations are at a decline at a time when reliable hydrological monitoring networks need updating with new equipment and digital media. There has been little interest in analyzing temperature patterns in the region, given its overriding critical role and increasing evidence of temperature controls of important physiological processes in insects, plants and crops. Diurnal range in temperature, frost conditions, and lowest temperatures are important in controlling flowering and fruiting, as well as the life cycles of some insects. At the global scale, thresholds in temperature that would cause ecosystem damage are being sought, and these are likely to be early signs of adverse impacts of climate change on terrestrial ecosystems. Analysis of temperature elsewhere has shown significant changes in minimum temperatures (e.g. DeGaeteno 1995, Karl 1996, and Easterling et al. 1999 for the United States; Plummer 1999 for New Zealand; and Heino et al. 1999 for Northern and Central Europe). General climate scenario Climate variability, extreme events and CLIVAR Many studies agree that extreme climate events will increase or get more intense in the future under a changing climate (IPCC TAR, IPCC 2001). There is increasing awareness of when and where these extreme events occur, as well as studies linking them to large-scale processes such as ENSO and ocean temperatures. These kinds of studies have not been done in Kano region. The Africa Climate Program of CLIVAR (Climate Variability and Predictability Project of the World Climate Research Programme—WCRP) has developed an implementation plan that is expected to improve our understanding of the nature of climate variability in Africa and will hopefully lead to improved climate models and regional climate predictions in Kano region.

The CLIVAR activities are expected to produce results that will greatly enhance our understanding of how climate is changing and some explanation of the climatic processes leading to recent damaging extreme events, such as the floods and droughts of 2007/8 in southern Africa. Improved understanding of the ENSO will improve climate forecasting and, in turn, increase success of adaptation measures. Possible spatial and temporal shifts in climate Communities in Kano region have developed livelihoods and traditional land uses suited to prevailing climatic conditions of their local environment (Mortimore, 1989). Types of cropping and farming systems have evolved to take advantage of seasonal patterns and amount of rainfall. Planting calendars and related preparatory work have all evolved with a long-term understanding of climatic conditions, although seasonal forecasts of rainfall are increasingly being used to fine-tune planting dates. Global climate change is likely to result in major shifts in climatic conditions at any given sub-region as shown by regional modeling studies such as Semazzi and Song (2001), both in space and over the year. This is likely to disrupt growing conditions and result in crop failures, and would have serious implications for food security. People in several parts of Africa including Kano region are currently experiencing such crop failures due to erratic and shifting patterns in rainfall, but these cases are not always documented. Systematic documentation and publication of these cases is required to build up a knowledge base of how much damage is occurring and where. Current national annual statistical summaries need to incorporate details that will contribute to this monitoring of climate change and its impacts and information that will be very useful in national communications to the Framework Convention on Climate Change. Knowing when conditions have changed sufficiently enough to warrant a change in land use, such as which crops to grow, is perhaps one of the bigger challenges facing communities.

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Land-surface feedbacks and desertification There is growing recognition of the nature of feedbacks between the land surface (land cover, surface albedo and soil moisture) and the atmosphere, and how these land-surface properties themselves are impacted by climate variability, land use and land degradation (Hunt 2000, Nicholson 2000b). Studies show that global ecosystems are stabilized by a series of feedbacks between man, animals, soils, vegetation and climate (Schlesinger et al. 1990, Graetz 1991); in undisturbed semi-arid environments in equilibrium, the feedback loops tend to be negative, hence preserving the status quo, while the disturbances induced by desertification make some of the feedback loops positive, allowing the disturbance to be amplified. Thus the potential exists for desertification to become self-accelerating, with droughts promoting the process (Nicholson 2000b). There is a need to understand these linkages and feedbacks, with monitoring providing data to validate model results. There is an emerging international effort under the Global Terrestrial Observing System (GTOS) to strengthen the observing networks. Coordination between the land-cover change observation networks and the climate observation systems is needed to allow integrated analyses.

Land-use–land-cover change The study of land use is fundamental in attempts to link production systems with climatic, social and economic processes and to determine how these contribute to sustainable development. A few case studies at the local level exist in Kano region, but there is a general lack of synthesis of land use going from the local/community levels to the regional level. The land use modeling components of global integrated assessment models (IAMs) such as IMAGE 2 (Alcamo 1999) do not contain the level of detail required for national level land-use planning (Desanker et al. 2001). In principle, it is now possible to develop detailed land-use change models for most areas like Kano region by using remote sensing data (such as those from Landsat 5 and 7) and socio-economic data that is available . The recent de-commercialization and open data policy of Landsat 7 has opened up access to regional scientists and made data available at affordable prices. The global acquisition strategy of 97 Landsat 7 collects data over parts of Africa where in the past data collection has been sparse due to the absence of ground receiving stations. Verification and validation of derived products from these remotely sensed observations is critical in getting the community (global and regional to local) to understand the potential and limitations of these new data sets and to recognize these new types of evidence of change. Studies of land use also enable the human dimensions of climate change to be properly placed in the context of livelihoods and social

development (Vogel et al. 2001). Understanding people’s perceptions and responses to climate and extreme events such as droughts enriches our ability to assess impacts of climate and how adaptive capacity can be enhanced. Incorporating grassroots indicators and GIS Mapping tools have been used to effectively demonstrate and defend environmental grassroots indicators based on the knowledge systems of local people (Peluso, 1995). Following the route of applied anthropology of indigenous classification (Omotayo and Musa, 1999; Sillitoes, 1998). Such work has come to champion the epistemological diversity of land classification and management, local understandings and creating powerful maps of that knowledge (Robbins and Maddock, 2000; Rundstrom, 1995;Weiner et al., 1995). GIS of local knowledge, still in its infancy, none the less can help to break apart the boundaries inherited from more traditional approaches to local knowledge, and so open onto broader explorations of ecological knowledge. GIS and remote sensing can be used to explore and delimit differences, and to analyze the partiality of GIS practitioners themselves, both as champions of positivist science and of local empowerment. Studies in local knowledge and grassroots indictors are rare in the Kano region despite the recognition of the role its play in validating scientific knowledge and ensuring local participation and acceptance of researches. Kano region: Required scenario development and location-based studies The IPCC have released their latest global emissions and social-economic scenarios (SRES Special Report, IPCC 2006) to replace the much used emissions scenarios of 1992 (IS92). The SRES provide a series of plausible emissions scenarios based on assumptions about the future evolution of major drivers of emissions, namely technology, economics, energy and population. While these drivers are given at the Africa level of aggregation (or sub-Saharan Africa in some cases), they provide a methodology and upper bounds for Africa that would be useful to provide more detailed projections at regional level. There are studies from the social and political sciences on Africa that explore future scenarios, e.g. ‘Farewell to Farms’ (Bryceson and Jamal (1997). It will be important to engage in research to develop social-economic scenarios for Kano region that reflect what is known more clearly than global assessments are able to. The issues of development are likely to have overriding influence on any future scenarios for Kano region, making it critical that a solid understanding of development be included in the further development of scenarios.

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Data issues, monitoring and documenting evidence of climate change Those working in Kano region in general often bemoan the lack of data for research, and this depends a great deal on African access to the latest information technologies. There is a wealth of information on Kano region and Africa in general from satellites, global studies, and various sources, and increasingly this information is being deposited on Web sites across the world. A useful collaboration between international initiatives and local ones is needed to capitalize on many land-cover monitoring activities now underway. The development of the Miombo Network for Southern Africa (Desanker et al. 1997) and the OSFAC science network for Central Africa (Mayaux et al. 2000) provides good examples of this collaboration.The data collected by these monitoring systems also need to be archived locally to make them more accessible for regional studies such as those in Kano region. For climate data, precipitation and temperature data are usually archived in openly accessible data centers such as the NOAA NCDC (http://www.ncdc.noaa.gov). However, the density of stations is still very low for Kano region, and in any case, they do not fully represent the climate data that is collected and archived in many meteorological stations. There is an ever-increasing need for access, in a timely fashion, to these data in order to evaluate major events, such as droughts and floods, as they occur. Weather-map satellites are a useful source of data for analyzing observed climate at the regional scale (e.g. Jury and Majodina 1997). Although many African countries including Nigeria are able to receive weather-satellite information, many do not have archiving facilities. There is an urgent need in Kano region to extend to analyses of human and ecological systems and how they have been impacted by climate. The latest IPCC report (TAR,2008) emphasized documentation of evidence of climate change and impacts—, there are very few studies to go by in Kano region, despite the many obvious impacts of climate. Past extreme events in Kano region, especially droughts, floods and storms, provide useful analogs of what future adverse impacts might involve. The progression of these events, and their economic and social impact, levels of damage, human response and recovery, offer useful guidance in devising future adaptation measures. While experiments in adaptation are harder to do, it would be useful to test methods for adaptation that would assist the climate change convention in their implementation efforts in the region. It will be necessary to be very specific about significant impacts for the region in future, rather than rely on the usual hand-waving about the Kano region being very vulnerable because it is poor, and so on. Regional specificity is

required. There is a need to study the latest IPCC reports for major findings and to enrich those conclusions dealing with local context. It would be very valuable to translate the IPCC TAR findings into statements that policy makers and resource managers can use in Kano region.

Scientific capacity building and climate change An important issue for Kano region is the need for increased capacity to undertake climate change research. There are a considerable number of scientists in KUST, Wudil and Bayero University with keen insight into the processes that shape their environment, but few of these are addressing questions of global climate change. Between these two institutions, looking at the curriculum there is no specific course on climate change except in passing in most of the climatology courses! There is an urgent need to build strong programs in environmental science, particularly, those that will produce interdisciplinary scientists capable of tackling the global climate change. The shortage of resources for basic research points to the need for strong and ongoing collaborations between Nigerian universities and universities abroad.

Integrated Assessment and Modeling for Kano region Quantifying sensitivity to climate change, societal resilience, adaptive capacity and the costs of impacts are major gaps in our current assessment of climate change in Kano region. Research is needed to test approaches and indicators for Kano region, building upon available data and, at the same time, identifying gaps and suggesting new data that need to be collected. It is possible that development of integrated assessment models (IAMs) will address elements of this issue. IAMs are becoming tools of choice for assessing impacts and adaptation options for climate change. When policy responses are implemented in IAMs linked to biophysical, climatic, social and economic processes, consistent evaluation of adaptation and vulnerability becomes possible. Many of the extant IAMs are global and necessarily aggregate regions based on economic activity; thus, Kano region and indeed the whole of Africa are always aggregated into one region. While the outputs from these global IAMs are suitable for global assessments, they offer little guidance to the sub-regions. It is therefore critical that regional IAMs be developed for Kano region, with incorporation of regionally relevant issues of sustainable development clearly highlighted. These would greatly enhance future assessments and any plans to identify projects that would help in adapting to adverse impacts of climate change. Activities should center on developing a comprehensive land-use-change model that would couple ecosystems, production and development plans, given the physical, economic and climatic factors of the region as the basis for planning and response actions.

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Existing global IAMs do not have the resolution over Kano region to capture the important processes and constraints to land use and development. Place-specific studies are needed, and the emphasis would shift accordingly. Studies and sub regions at which the integrated assessments should be carried out include, River basin integrated studies; Local studies; Desertification and climate change; ENSO; Multiple stresses, feedbacks and thresholds; Livelihoods, development and climate change and Identification of climate hazards to guide adaptation activities.

CONCLUSION Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level. Many natural systems, on all continents and in some oceans, are being affected by regional climate changes. Observed

changes in many physical and biological systems are consistent with warming. Climate change is one of several major environmental issues that Kano region and indeed Nigeria must participate in. The others, including combating desertification, conserving biodiversity, and sustainable development, demand equal a attention. Research in Kano region could be designed to address many of these issues concurrently, and the suggested integrated modeling would assist in providing the necessary linkages to policy and other societal needs. The predicted impact of climate change in the ecosystems, politics and social systems of Kano region demand that impact studies consider these factors explicitly. Extreme climate events are likely to be a major area of concern over the coming decades—this requires more monitoring and analysis of observations and development of new techniques for identifying potential climate hazards in very specific geographic term.

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LAND TENURE ISSUES IN KANO RIVER IRRIGATION PROJECT 1980 – 1999: THE CHIROMAWA EXAMPLE

A. M. Dambazau Department of Geography, Kano University of Science and Technology (KUST), Wudil, Kano state

abalhafsah@ yahoo.com

ABSTRACT The paper focused on finding the likely changes in land right systems that might have taken place due to the introduction of one of the largest irrigation schemes in West Africa within a densely populated region. Standardized interview schedule was used to collect data from two hundred sampled households. The sampling frame was derived from the 1991 national population household listing and numbering register, and then a simple random sampling technique was used to select the sample. Findings reveal the dominance of land acquisition methods which confer permanent usufruct with inheritance as the dominant means though it is on a decline, while purchase and loan are on the increase. Also half of the sampled respondents held land which is less than two hectares in size. The paper recommended the strengthening of the existing farmer’s cooperative to help them have access to loan and credits to help them cope with the financial demand of irrigation agriculture and increase security of tenure.

Key Words: Land tenure, Irrigation agriculture, Land holding, Usufruct, farmer’s cooperative.

INTRODUCTION A number of strategies were introduced by various governments in Nigeria in order to improve the welfare of the rural populace among which is the introduction of large scale irrigation projects. The Kano River Project located within the densely populated Kano Closed Settled Zone (KCSZ) is one of such projects which involve the acquisition of large tracts of land as its key feature. Its introduction in such area of high population density coupled with the capital intensive nature of irrigation agriculture is bound to have a serious impact on the man- land relationships. This is based on the premise that increase in population is a stimuli for agricultural and land use changes (Boserup, 1965). The paper, therefore, focuses on the post implementation analysis of the project over a period of twenty years with particular emphasis on land tenure issues in order to identify changes in the man- land relationship and its implication for the overall objectives of the project.

An Over View of Land Rights Changes in Northern Nigeria Land tenure has many definitions in the literature depending upon the author’s background and perception. It is seen by some as the major impediment to modernization of the agricultural sector in the country (Aliyu, 1986). It has been defined as a body of rules governing the ways and means through which rights and obligations are created and extinguished in land (Aliyu, 1986). It is concerned with the allocation of resources among the individuals of the community, both severally and communally. However, the need of society changes as they enlarge or contract and diminish and also as their impact on the environment alters in various ways (Lowe, 1986). An individual or group in a community can get access to land through two major processes; those that confer permanent usufruct rights and those that confer temporary usufruct rights. Studies in various parts of Hausa

land by Meek (1957), Baba (1975) and Main (1987) identified inheritance (gado), allocation by head or state, gift(kyauta) and purchase (saye), as the means by which individuals can get permanent rights to land. On the other hand trust (riko), share cropping (noma muraba), loan/ lease (aro) and pledge (jingina) are means by which land rights can be entrusted temporarily to an individual.

It is important to note that increased population pressure, the Fulani Jihad of 1804, colonial land legislations and the introduction of large scale modern irrigation scheme have had a serious impact on the land rights system within the study area and the northern Nigeria as a whole. Studies carried out in the 20th century by Smith (1955) Marshall (1960) and McDonnell (1966) cited by Saidu (1994) agreed that during that period, land was entrusted in the hands of the clan’s head in trust for his people, however, they had no claim of ownership in it themselves. An individual had right to share in the use of the land, and held it in perpetuity subject to the performance of some obligations. But no member has the right of alienation, sale or mortgage. Every member of a family had a right to share in the land and the right was not forfeited even on prolonged absence. The people were organized under clans with series of lineages, and the basic unit of most of these lineages was the extended family system. The people were organized under a unit called gandu (Hill, 1970; 1977). It is the consensus of most of the authors that the gandu is a unit of domestic economy, producing the majority of its grains supplies and consisting of two or more male adults, usually married together with their wives and children (Smith, 1955; Hill, 1970; 1977; Goddard, 1972& 1973; Norman, 1973; Baba, 1975 Wallace, 1979; and Usman, 1978). The decline of gandu as an institution in which land holding is organized has been reported by Hills, (1972), Buntjer (1973), Goddard (1973), Baba (1970) and Wallace (1979).

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Agents of Land Rights Changes The agents of land rights change in the northern parts of Nigeria are identified below. The Fulani Jihad (1804-1900) The Fulani Jihad of 1804 brought changes to the customary land tenure system. The Shariah law recognizes various forms of sale, pledge, loan, and sub division by inheritance and the right of woman to inherit land. The Colonial Rule The Fulani aristocrats were conquered by the colonial masters from 1900 which marked the beginning of land tenure legislation in northern Nigeria. This period is also characterized by the introduction of taxes and export crops. Also, the various forms of land transaction were reported ranging from pledging, loaning, gift and sale (Wallace, 1979). The Post Colonial Legislations After independence the 1916 Land and Native Rights Ordinance was transformed to 1962 Land Tenure Law and later the 1978 Land Use Decree. The 1978 Land Use Act gives the government the absolute right to remove land from the peasants for public good. Thus, the government began acquiring large tracts of land for developmental purposes one of which is the Kano River Project with its consequent changes in the man – land relations (Orogun, 1985). In the same vein, Wallace (1979) observed that the project has completely altered the social structure in the area. Similarly, Baba (1983), observed that although the policy on KRP is to reallocate land to the farmers an equivalent of the land they held before irrigation development subject to 10% reduction, the possibilities of new social processes capable of distorting the traditional patterns of land distribution are high. He found that between1971 to 1979, the top 10% of the people owned 34.4% of irrigated land, while the bottom 10% owned only 2.8% of irrigated land. This view is supported by Wallace (1979); Orogun (1985); Igbozurike (1982); and Hill (1977). It is vital to note that in their various studies, Baba (1975) on KRP and Main (1987) at Jakara and Warwade observed that a number of land transactions have little or no significance. There was no incidence of share cropping, gift and land allocated by village head which they attributed to the absence of permanent bush in Kura District, while they attributed the low incidence of pledge, share cropping, lease/ loan to the insecurity of tenure associated with them. Similarly, their findings revealed that 9 out of 10 farms were held under permanent usufruct, mainly through inheritance (almost 7 in 10) and purchase (almost 3 in 10), which they attributed to their maximum security of tenure.

The Study Area Physical Setting Chiromawa town is located within the tropical continental north, with a mean monthly temperature of about 27.5oC and an annual range

of 110C. It lies within the Zone of seasonally fluctuating Inter Tropical Convergence (ITC). The rain fall is single maxima with annual total of about 864mm, concentrated from May to September while from October to April there is no rain. It is therefore the seasonality of rainfall within the area which necessitates the introduction of large scale irrigation.The area falls within the Chad Basin inland drainage with Rivers Kano and Challawa as the two main major rivers which are the major tributaries of river Hadejia. The Kano River was dammed at Tiga where water from the reservoir is used for irrigation during the dry season (Fig.1). Socio- Economic Background Chiromawa is one of the oldest Hausa towns, located within the present Garun Mallam Local Government Area of Kano state. It has an estimated population of about 10,000 people consisting of three centralized wards (Waziri, Sintili and Kasco) and a scattered hamlet called Kwari. The compounds in the town are mostly built with mud along narrow streets .However, the Kwari ward differs from others as it is scattered and divided in to two: the main Kwari and the Kwari Bakingada. The former is peopled by mostly old men and women while the latter is occupied by mostly adults and young men who migrated from the main Kwari because of better accessibility to the main road and non farm occupation. Agriculture both rain fed and irrigated constitute the major occupation of the people, though the Kwari people are fishermen and combine fishing with rain fed agriculture.

Choice of the Study Area The choice of the study area among other villages is guided by the following considerations.

• The area is almost similar in terms of size with other villages/ towns in the KRP.

• It is less densely populated being located within the west branch region of the irrigation project

• Represent the spatial pattern of settlements in the region, as it has both a nucleated and a disperse ward. The centralized wards can represent the situation in the nucleated villages while the dispersed Kwari ward gives a good picture of the situation in disperse villages and in areas where irrigation farming in not taking place.

• Most of the towns are located on the Kano -Kaduna express road, while some are located on the Kano River. Thus, the main town is located on expressway while the Kwari ward is on Kano River which represents the general pattern in the area.

It is therefore hoped that the findings from the study can be used to make generalization about the project area.

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Fig.1: Map of Kano River Project Showing the Study Area. MATERIALS AND METHODS Data Collection The data collection exercise involve the use of standardized interview schedule to collect information from the respondents. Because of the homogeneous nature of the respondents, two hundred households were sampled representing 5 % of the population, with fifty respondents selected from each ward because the wards are of almost equal size. The sampling frame based on the number of house holds in each ward was compiled from the 1991 National Population Commission household listing register. The ward heads with the assistance of five people from each ward helped to confirm the list. Then, a simple random sampling was used to select the respondents. The interview schedule consisted of questions that deal with issues of land ownership, number and size of fields, methods of land access, tenure

status, family composition, labour use etc. In determining the size of land holding no physical measurement was made based on the assumption that the farmers can correctly state the size of their individual holdings based on many years of experience with irrigation farming and the fact that the fields were previously measured. However, effort was made to test the validity of the respondent’s information by asking other people’s opinion about the size of the land the respondents owned. Though there was no much difference between what the respondents said and what the community said, a 5%, 5%, 6% and 10% distortion was recorded for Waziri, Kasco, Sintili and Kasco wards respectively. Data Analysis Since the data is descriptive in nature, the use of descriptive statistics, tables and percentages were employed in the analysis.

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RESULTS AND DISCUSSION Methods of Land Access Table 1 reveals the various forms of land rights by which individuals get access to land and their prominence in the study area.

The data shows that 1 in 2 of the plots is inherited, 1 in 4 of the plots is purchased while about 1 in 5 of the plots is acquired through other means with no incidence of share cropping.

Table 1: Forms of land rights transfer by number Holdings in Chiromawa. S/NO. PROCESSESS NO. PERCENTAGE 1. Inheritance (Gado) 478 48.7 2. Purchase (Saye) 235 24.0 3. Trust (Riko) 35 3.6 4. Gift (Kyauta) 03 0.3 5. Pledge (Jingina) 13 1.3 6. Lease / Loan (Aro) 212 21.6 7. Allocation (Kyauta) 05 0.5 8. Shares cropping (Noma muraba) ____ ____

Source: Field work, 1999. Similar pattern emerges when the data from each ward is studied. Table 2 shows that about half of the total fields in each of the sampled locations are inherited, while about a quarter of the fields are acquired through purchase. Thus, inheritance and purchase are the dominant forms by which land is acquired. This is slightly different from what Baba (1975) found in the same area, where

he found that 7 in 10 of the land are held under inheritance and 3 in 10 by purchase. This variation may be attributed to the increased value of land as the people now prefer to lease their lands than dispose them completely as a result of the project which commence effectively in 1975/76 irrigation season.

Table 2: Forms of land rights transfer by Number of fields acquired in four wards of Chiromawa.

PROCESSESS WAZIRI N=241

SINTILI NO=210

KASCO N=250

KWARI N=280

TOTAL

NO % NO. % NO. % NO. % NO. % Inheritance (Gado) 120 49.9 84 40.0 87 38.8 187.6 67 478 48.7 Purchase (Saye) 68 28.2 47 22.4 71 28.4 49 18.0 235 24.0 Lease/Loan (Aro) 47 19.5 66 31.4 76 30.4 23.5 8.0 212 21.6 Pledge (Jingina) 2 0.83 7 3.3 4 1.6 - - 13 1.3 Gift (Kyauta) 2 0.83 0 0 1 0.4 - - 3 0.3 Allocation - - 1 0.5 - - 4 1.0 5 0.5 Share cropping (Noma Muraba)

- - - -

Trust (Riko) 2.0 0.83 0.5 2.3 11 4.4 17.0 6.0 35 3.6

Source: Field work, 1999. The results in Table 3 also show that despite the dominance of inheritance as the means by which land right is acquired, its relative significance is declining. The data shows that inheritance declined by 20% from 67.9% in 1971 to 48.7% in 1999, while the incidence of purchase on the other hand rose from 20.0% in 1979 to 24.3% in 1999, a slight increase of 4%. The data also indicates the increasing incidences of loan/lease, as 1 in 5 of the fields are held under this form of land rights. This form rose significantly from

5.0% in 1971 to 21.6% in 1999, an increase of 17.3%. Its high increase can be attributed to the capital intensive nature of irrigation agriculture most of the poor farmers can not afford to cultivate all their fields and are not willing to sell their lands. At the same time they use the accruing capital to cultivate the remaining fields. Another reason is the unwillingness of some of the farmers to grow recommended crops by the irrigation authorities.

Table 3: Forms of land right on Kano River Project 1971 to 1999.

PROCESSESS 1971*1 1979*2 1999*3 Inheritance (Gado) 67.9 62.0 48.7 Purchase (Saye) 26.7 20.0 24.0 Loan/Lease (Aro) 5.0 16.8 21.6 Pledge (Jingina) 0.4 1.2 0.5 Source *1& *2j, Baba 1984 *3 Author’s field work, 1999

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The results from Tables 1, 2 and 3 show that some methods of land transactions have declined significantly. The low incidence of pledge (1.3%) and trust (3.6%) corresponds closely with the findings of Baba (1971) and (1979) where he recorded a much lower incidence in the same area. However, despite its low incidence two forms of pledge were identified;

• An agreement is made between the pledgor and pledgee on a specified sum of money in lieu of land. The pledgee will hold the land in his possession and will be required to pay the seasonal rent for the land, until his money is repaid.

• The calculated seasonal rents of the land will be deducted from the total money collected from the pledgor, until the money is fully repaid. As for example the total amount is N20, 000= and the seasonal rent is N2000=. The land will return to the original owner after ten years for upland farms and five years for irrigated farms (since they are cultivated twice a year).

From the discussion above it can be seen that methods that confer permanent usufruct account

for about 7 in 10 (72.9%) by which land is acquired. However there is a decline of about 21.7% if compared with the average obtained by Baba (1971) in the same district. There is also an increase in the rate of loan/ lease from 5% in 1971 to 22% in 1999.

Size and Distribution of Land Holding Land is central to all rural resources and the primary means of rural wealth. It is therefore of vital interest to look at its distribution. Findings from the study show that almost half of the sampled respondents held land which is less than 2 hectares in size. The data in Table 4 shows that almost 1 in 4 of the respondents held land which range from 0.4 to 1.9 hectares with less than 2 out of 10 of the respondents having over 6 and above hectares. The general pattern in the area differs slightly with the earlier findings in the same district and else where in Hausa land. As for example the Netherlands Consults (NEDECO) which were the project consultants, observed the range of land holding to be 0.3 to over 4 hectares, while Baba cited in Wallace (1979) found the average to be 2.1 hectares with a range between 0.4 hectares and 2.8 hectares.

Table 4: Distribution of Hectares Held by Respondents per Wards.

CLASSESS (HECTARES)

WAZIRI KASCO SINTILI KWARI TOTAL %

0 >0.4 >0.7 0.8-1.9 2.0 – 4 4.1-6.0 6+

1 1 4 15 17 7 5

1 1 9 17 11 4 7

1 1 8 20 12 4 4

- - 2 7 10 9 20

3 3 32 58 52 25 36 200

1.5 1.5 11.5 29 26 2.5 18 100.0

Source: Author’s field work,1999.

The Effect of Landlessness There are two commonly held notions associated with irrigation in northern Nigeria i.e. ‘Noman rani maganin talauchi’ (Irrigation farming is the solution to poverty) and ‘Noman rani maganin cirani’ (Irrigation farming is the solution to seasonal migration). But it becomes difficult to comprehend the validity of the above statements if the assertion of one of the respondents is considered when approached for an interview; ‘Young man to me there is nothing good or positive about this irrigation farming. It has become a taboo to me and my family’. The respondents said prior to the introduction of the scheme his family owned over 40 hectares of land at Kadawa, which is presently occupied by government farms, workshops and staff quarters. But all the land was confiscated and a meager N200= was given to the family as compensation in 1976.. From Kadawa the family was re-settled

at the eastern side of the project and were later displaced and settled at Chiromawa. Presently, the family is landless and cannot afford to buy, lease/ loan a land for farming, thereby throwing them deeper in to the poverty trap. This is an indication that there are a number of people in the area who have become distressed because of some policies e.g. monetary compensation which led them to lose their major source of livelihood completely, living them in perpetual poverty. However, effort was made to verify the validity of the respondent statement to ensure that he is not among those farmers who were given lands some where less 10% of their original holdings but refused and sold their allocation and found his statement to be true. It is vital to note that though there are other farmers who fall into the same situation as the above respondents, majority of the people are reaping the abundant benefits brought about by irrigation agriculture.

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CONCLUSION This study has shown some evidence of changes in land rights system as a result of the introduction of large scale irrigation project for a twenty- year period. Emphasis was placed on finding the popularity of various methods of access to land and the land holding size. From the analysis the bulk of the land is held under permanent usufruct which accounted for about 70%.

The findings also indicate an increasing shift towards free hold tenure due to high incidence of purchase which consequently leads to concentration of more land in the hands of the privileged few. Finally, the study has helped to fill in the data vacuum that existed in the area with regard to land tenure as the last major research on the issue was carried out in 1979.Based on the findings recommendations stated below are proffered.

RECOMMENDATIONS Since, the objectives of large scale irrigation project such as the KRP is to bring equity in the distribution of resources and overall improvements in the living standard of rural people, certain measures need to be taken which include; • Since irrigation agriculture is a costly venture and

the small farmer is a deficit farmer who depends on big farmers or urban based capitalist for loans to purchase land, inputs, etc the need to

strengthen the existing farmers’ cooperatives such as Fadama Users Association (FUA) and Water Users Association (WUA) is very essential. This can help them to obtain loans, credits, services and sell their produce at better price. This can also help to sanitize the present ineffective methods by which fertilizer targeted for the farmers at subsidized rate end up in the hands of the politicians, large farmers and urban based bureaucrats. Such fertilizer should be allocated through the farmers’ cooperatives.

If such a measure is taken, it will considerably reduce the incidence of farmers selling or leasing their lands to acquire inputs.

• Measures should also be provided to increase security of tenure for farmers occupying land on lease/loan. This will help to increase productivity as the farmer will not be reluctant or unwilling to improve the fertility of the land for fear of eviction.

• Government should also look at the case of distressed farmers with a view to rehabilitating them by providing them with money to lease land and acquire inputs for a two year period under close supervision by the project staff. This will help some of them to bounce back economically and feel the positive impact of the scheme like many others.

REFERENCES Ali, M. (1986),Fadama Irrigation and Right to Land

and Water in Parts of Borno State. Unpublished M.sc Thesis Bayero University, Kano.

Baba J.M. (1975),Induced Agricultural Change in a Densely Populated District: A Study of the Existing Agricultural System in Kura District and the Projected Impact of the Kano River Irrigation Project, Kano State, Nigeria unpublished P.H.D Thesis, Ahmadu Bello University, Zaria.

Baba, J.M. (1984),The problems of Rural Inequality on the Kano River Project. In swindle K.etal(ed) Inequality and Development. Case Studies from Third World.Macmillan Publishers. .

Buntjer, B. (1973),Rural Society in the Zaria Area: the Changing structure of Gandu. Samaru Bulletin,no.180, p.6.

Goddard, A.D. (1973),Changing Family structures among the Rural Hausa. Samaru Research Bulletin, p.214.

Hill, P. (1970), Studies in Rural Capitalism in West Africa. Cambridge, C.U.P

Hill, P. (1972), Rural Hausa: A Village and Settings, Cambridge,C.U.P.

Hill, P. (1977), Population, Prosperity and Poverty: Rural Kano 1900 and 1970. Cambridge,C.U.P.

Lower, R.G (1986), Agricultural Revolution in Africa. Mac.Press:London.

Main, H. et al (1987), Recent Changes in the Transfer of Land Right in Hausa land, with Kano State Example. In Olofin, E. and Patrick,S.(ed) Land Administration and Development in Northern Nigeria. Case Studies.

Meek, C.K (1957), Land Tenure and Land Administration In and Cameroon. Her Majesty Stationary Office: HMSO

NEDECO, (1976), Kano River Project: Part 3, Irrigation and Drainage, P. 45.

Norman, D. (1972), an Economic Survey of Three Villages in Zaria Province Samaru Miscellaneous Paper 33

Norman, D. (1973), Economic Analysis of Agricultural Production and Labour Utilisation Among the Hausa in the North of Nigeria: Samaru Research Bulletin, No. 199, P. 8.

Olatunboson, D, (1975), Nigeria’s Neglected Rural Majority: Ibadan: Oxford University Press. NISER.

Orogun, E. (1985), the Administration of Irrigated Land on the Kano River Project Unpublished M.Sc. Thesis,Bayero University Kano

Sa’idu, M.M. (1991), Land Tenure Issues in and Around Thomas River Project Kano State,Unpublished M.SC. Thesis Bayero University Kano.

Sai’du, M.M. (1994), ‘Land and Water Rights in Fadama Lands of Northern: Agricultural Co-ordinating Unit (FACU) and Fadama Development: Policies and Experiences’:in Kolawole, A. et.al (eds) Strategies for the Sustainable use of Fadama Lands in Northern Nigeria CSER/ABU (Zaria) IIED (London) P.91-95

Usman, B. (1978), The Transformation of Katsina (1400-1883). ABU Press.

Wallace, T. (1979), Rural Development through Irrigation: Studies in Town on the Kano River Project; Research Report No. 3 (Centre for Social and Economic Research, ABU, Zaria.)

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“DAMMING OR DAMNING?” CRIES OF THE PEOPLE DOWNSTREAM OF RIVER WATARI DAM IN KANO STATE

Ibrahim Badamasi Lambu Department of Geography, Kano University of Science and Technology, Wudil, Kano Nigeria.

[email protected]

ABSTRACT This paper examines the post dam impact on domestic and irrigation activities downstream of the Watari Dam in Kano state. Participatory Rural Appraisal (PRA) techniques and structured questionnaires were used in generating data in three selected stations downstream of the Watari Dam. The study revealed that only areas at the vicinity of the project benefit positively while the downstream community suffer serious problems ranging from inadequate water for domestic and irrigation purposes. Some of the reasons for the problems include hoarding of the water. The management releases the water from the Dam at rainfall peak (to prevent Dam breakage). Immediately it is dry season the river ceases to flow and the channel becomes a sand deposit that attracts sand transactions (Tippers, Trucks, Pick- ups, etc) that contribute to further deterioration of the environment through erosion through which some farms are lost to slope failure. Responses and advises were tendered on how to solve the problems. Measures such as continued release of water during the dry season will bring a lasting solution to the declined dry season farming and artificial erosion by sand dealers.

Keywords: Downstream, Damming, Water resources, Irrigation and Participatory Rural Appraisal (PRA). INTRODUCTION The Kano state Government has for over 40 years opted for construction of storage reservoirs (Dams) in different part of the state. This was intensified in response to the drought that hit the northern part of the country around the early 1970’s. Dam construction was aimed at solving the acute shortage of water for both domestic and irrigation uses. The irrigation is meant to supplement the food demand that cannot be met by rainy season farming due to the effect of drought. Government was worried about the fear of importing food from other countries. It was argued that by the late 1980’s , cities of developing world were required to import half of their food (IDRC, 1994).The state Government embarked upon one of the largest Dam building programmes in Nigeria as a matter of priority for large scale irrigation development. As from 1970 to date, more than sixteen Dams of all size have been constructed with a total storage capacity of about 3billion cubic metres.

Dam and damming play significant role in the history of man’s achievement on earth. Dam provides major source of Hydro Electric power. Before the advent of Nuclear Technology for power supply, dams provided 93% of world power supply RHSQ (2005). Other uses include domestic water supply, stabilized water for irrigation, flood prevention, land reclamation, water diversion and recreation. The contribution of dams at national level can be cited from the Kainji dam that provided 62% of power supply (MOP 2006). In Kano state, dams such as Chalawa Gorge, Thomas, Kusalla etc are very important sources of water for domestic and irrigation uses. Watari dam has improved the livelihood and brought tremendous development to the town of Bagwai (Lambu 2003) The Watari irrigation development represents an intermediate situation between the small-scale

‘Fadama’ development and the large-scale schemes in the state for irrigation development. The valley covers a total area of approximately 800hectares on both sides of the river that was dammed in 1981, near the town of Bagwai in Kano state.

The improved relationship that existed between the state and other north-African countries such as Sudan and Egypt stimulated Kano for dam constructions. The project was intended to solve shortage of domestic water and to supplement the food production with irrigation. At the onset, dam project was located in the north-western part of the state. This explains the reason for the location of over 75% of dams in the present Kano from the then old Kano state. Dam project contributes tremendously to the economy and general wellbeing of people in the state. Apart from the supply of food, employment opportunity is created at farm, market and in commuter services. Irrigation based on dam projects contributes over 400% to the socio-economic status as compared to the rain fed farming activities (KNARDA, 1998). Farming under irrigation involves pure cultivation of cash crops such as wheat and vegetables which accelerate income generation and revenue to the farmers and Government respectively. People are kept busy all the year round and hence it reduces outward migration with increasing attachment to land for farming.

Projects are discovered to have both positive and negative effects spatially and temporally on the community. Hence there is need to have closer study on the Watari Dam with a view to assess the socio economic effects of the project. People are made to suffer undue hardship as a result of developmental projects.

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As states and trans-national corporations seek control over resources and territory for development, so the inhabitants of the areas concerned are frequently displayed and economically marginalised (Guha 1989). This study is geared toward better understanding of the environment, resources and human activities therein.

The aim of this study is to assess the socio-economic impact of Watari dam project on the downstream community of the River. To achieve the aim the following specific objectives were pursued; i. To delineate three spatial units (stations) at

the downstream of Watari Dam in order to conduct Participatory Rural Appraisal on the sampled population.

ii. To study the feasibility report from KNARDA and Ministry of Agriculture in order to retrieve the pre dam situation.

iii. To compare the pre-dam and post-dam situation using simple descriptive statistics to enable us visualise the impact of the Damming.

iv. To offer recommendations based on the findings.

The study will answer the following questions: (i) What are the major socio-economic

differences affecting the downstream community between pre-dam and post-dam periods?

(ii) To what extent is the dam responsible for the identified effects?

(iii) How can the effects be appropriately managed?

The Study Area Watari dam is cited close to the town of Bagwai at an approximate distance of 1.6km North-West of the LGA’s Head quarter. It was intended to serve four local government areas in Kano state namely: Bagwai, Shanono, Bichi and Tofa. Geographical location of the irrigation and reservoir is exactly between longitude 80 08’ and longitude 80 17’ East and latitude 120 05’ to 120 10’ North. About 60% of the irrigation project is in Bagwai LGA while the remaining 40% is shared by the 3 other LGA’s. The project covers an area of about 6, 800 hectares excluding the Dam site area. The land belongs to individuals that acquired it through the traditional land tenure system operating in the state. Land inheritance, lease, purchase, crop sharing etc were discovered to be in practice within the area.

The area falls under the Basement Complex rocks of Precambrian age. From top downwards the Basement Complex rock is deeply weathered to a depth of 7m near the village of Jobe and up to 9m at Marke town (KNARDA 1980). It forms an incised and dissected pediplain landscape around the Romo village.

Generally the landform can be described as plain with minor undulations cut across by valleys of smaller sizes.

It is characterised by a sudano - sahelian type of climate typically prevailing within Kano state. About 799mm is approximately the annual average precipitation record with 62% of rain around July and August of every year. Similarly average temperature is about 21 0 C around January and up to 310C around May (HASKONING 1981). The area falls in the Sudan savanna vegetation consisting of scatted trees, shrubs and grasses. Dense vegetation cover appears longitudinally by the river banks. The vegetation is man-made, consisting of economic trees ranging from mango, guava, bitter lemon and cashew trees that were either planted by farmers or propagated naturally during settlement of seeds as river load. There are mark changes due to artificially induced erosion by sand ‘scavengers’ threatening the nearby farm lands and the trees. Problems such as collapse of slopes and exposure of roots of trees are evidently visible in the area.

CONCEPTUAL ISSUES Dam construction and irrigation projects are considered to have long history. Immediately after the evolution of human settlement, construction of reservoirs began especially in areas of moisture deficiency. The end result of Damming has effect on both the environment and man himself. Wallace (1979) was of the view that “Damming changed flow regime of the river and alter the characteristics of the land downstream, thus causing hardship to the inhabitants whose means of livelihood used to come from and within the river”. Similarly Olofin (1982) argued that “man’s activities to regulate water resources have some effects on him because the characteristics being perceived are subject to change over time”. Intensive study should be undertaken before embarking on any project that has environmental concern to avoid undue damages and Hardship to the affected communities. As highlighted by Zimmerman (1988) that “no part of environment can be regarded as resources until it is capable of satisfying human needs”. Recent studies revealed the reason for rampant cases of drilling for under ground water. It was discovered that Basement complex formation (which affect Kano state) is having more problems than that of the Chad formation. Finding shows that low permeability of aquifers affect recharge of both Boreholes and open wells in the Basement complex formation (Adnan 2008). This warrant the need for proper management of both surface and sub surface water resources as the only option left to people. This is the rationale for constructing Watari Dam to serve the irrigation project in the area.

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Fig. 1: KANO STATE MAP SHOWING THE STUDY AREA SOURCE: FIELD WORK 2009

Research Methodology Two main sources of Data were used in this study i.e. primary and secondary data. Longitudinal coverage of the entire Watari River is not possible within the scope of this research. Purposive Sampling is adopted in order to cover the entire downstream areas. The primary data was obtained with the aid of structured interview through the Participatory Rural Appraisal (PRA) techniques where responses were gathered at three stations of 15km apart. The river is approximately 47.8km from the dam to the point of entry into R.Chalawa. A gap of 15km eradicates duplication of the sample and 3 distinctive stations were judged for administering the questionnaire. PRA is a technique of collecting data through observation, study, and analysis of prevailing situation independently without preconceived notion of the researcher. The respondents were met at site with structured questions such as what is your opinion about the damming of this river, etc to initiate the discursions. Varied responses from the audience help to obtain correct information i.e. matching the responses serves as automatic checks and

balances. The technique allowed observance; study and analysis of prevailing situation but if not controlled may lead to unwanted arguments independent to the research interest. At times it may rekindle some personal ill feelings among the groups without preconceived knowledge of the researcher. The secondary data i.e. pre dam panorama on the other hand, were obtained from the records kept by the KNARDA, Ministry of Agriculture and the Consultant Company (HASKONING NIG.Ltd).

The PRA involved one hundred and fifty respondents from three different points (50 each) who were given chance to express themselves on the past and present situations. In other words, 50 questionnaires were administered in each station.. The first point was the home of a traditional ruler (Mai gari), the second was a religious leader (Imam) and the last was vegetable market (Yan timatir). Exaggerations and underestimations are corrected by counter responses at spot. Dry season was selected as the study duration so that true and exact prevailing situation can be ascertained vividly.

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The study started from late December and lasted till third week of March 2009 which marked the actual dry season activities. Bagwai LGA kept important records on irrigation and water supply at the Agricultural department which gave additional information for this study.

RESULTS AND DISCUSSION FIRST STATION (At the home of traditional ruler): At the vicinity of the Dam near Yan Dabino market adjacent to Kiyawa town. People found here are resident of Bagwai, Kiyawa, Kuriri and Yartofa town. The project was found to have positive contribution to the inhabitants. Over 82%

expressed satisfaction with the Damming by giving the detail of how their livelihoods were improved. Increased food production in Rainy and Dry season as well as the employment opportunities created by the project is highly appreciated by the respondents. Crops such as vegetables and fruit crops are profitably cultivated. Fishing and fish trading is taking place in the area which engaged some reasonable number of people. Table 1 summarises how the community around station 1 percieved the difference in income and general situation between pre-dam and post-dam periods.

Table 1: Perceived conditions pre-and post-dam around station 1

Source field work, 2008

The table shows that 93% of respondents are in support of the project as they experienced improvement in their livelihood. Majority expressed their satisfaction with the project and gave no negative effect of the dam. It is important to note that the pre dam and post dam situation got 86.7% (v. poor) and 93.1% (v. good) respectively at the vicinity of the dam.

The study discovered that various crops such as cereals e.g. maize and vegetables e.g. tomatoes are heavily cultivated. Employment opportunities such as direct labour in the farm lands, basket making, up loading and transport working jobs are made available. Revenue

generation as well as income to the Local Authority is quite substantial. During harvest, about 480 to 560 baskets of tomatoes are loaded to Lagos and other states in the West and East. Each basket brings N100.00 as revenue to the Bagwai Local Government council as discovered at Yandabino Market.

According to National Union of Road Transport Workers (NURTW,) about 50 to 65 commercial buses and private cars paid revenues to the road union at station. Other occupations such as food selling, drinks’ kiosks and mechanics are found in the area.

PLATE 1: HARVESTING OF TOMATOES IN A FARM. Source field work 2009

Second station (At home of religious leader): The second station is at Rimindako and comprises people from R/dako, Marke, Tuga and Kuriri towns. About 52 people were subjected to PRA

and detail shows that the release of water is not in favour of dry season farming and hence they were made jobless.

EFFECTIVE PERIOD RESPONSES % OF PEOPLE WITH THE SAME VIEW

Pre dam income status Very poor 86.9%

Post dam income status Very Good 93.1% Positive effects Many 78.4% Negative effects None 69.8% General opinion on the project Satisfactory 82.5%

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Of them said “…these people are merciless, leaving us dry and doing nothing with the Fadama. In the month of August and September they rush the water on our farms removing our crops leaving holes and patches….”Others

complained that people in the area have to leave for Dry season migration (Ci rani) or else the entire community will perish in hunger and starvation. Table 2 summarises their view on the impact of the project.

Table 2: Perrceived condition pre-dam and post-dam around station 2

EFFECTIVE PERIOD ORDINAL STATUS PERCENTAGE Pre dam income status Good 96.9 Post dam income status Extremely bad 83.7 Positive effects of the Dam Nil 78.4 Negative effects of the Dam Numerous 69.8 General opinion on the project Need water flow in the dry season 82.5

Source: Field work 2009 It was discovered during the study that the youth are living home to urban centres in search of employment and this affects the population structure when the aged and the very young are left behind with females throughout the dry

season. In every home one is away for dry season migration. It was unanimously stated that the reason for this migration is purely due to lack of employment.

Table 3: Record of seasonal migration (ci rani) at station 2 DESTINATIONS RESPONSES PERCENTAGES

Migration to Kano city Frequent 52 Kaduna/Jos/Bauchi Often 34 Lagos/Abuja/Far south On the increase 14 Source: field work 2009 An aged person who now stays at home described the life at the city to be difficult and disgraceful. “We sleep openly, under bridge or home frontage’’. He said the job ranges from nail cutting, hard labouring in construction work and hawking. “Look at me the strength has gone, my sight is weakening how can I cope with the congested vehicle?” he asked.

A traditional midwifery (Ungozoma) met collecting traditional medicinal herbs( the only female interviewed due to purdah system where women are restricted from unnecessary movement) talked at length on the situation at present. She is unaware of the effects of the Dam but attributed the problem of the area to the dryness of Watari River. “People have now abandoned our ancestral way of life. During my teenage years, our grandparents used to observe some respect for the spirit of Watari and it sustained them to the end. Presently such traditions were regarded archaic; hence Watari is now holding back its water for over a decade. Immediately it is dry season Watari can no longer support a melon, quite unlike before when Sugarcane dominated the whole land. People like you must live their young wives and parents at home to Birni (city) to get new riga (clothes) by the dry season. I am affected because my son in-law left his wife (my daughter) for three years now; she is now with me since he sends nothing over the years. My son (referring to the

researcher) don’t wait up to sunset, Watari is dangerous….”

One can deduce some meaning from her responses that at least the river is dry and people are suffering etc but her perception on the cause for dryness of the river may is due to ignorance of the dam and traditional belief inherent with rural life.

Third station Janguza (Near vegetable market): The third station is furthest area from the dam. At this site responses were bitter and more empathetic. “Dry season period is the time for joblessness and the alternative is the Cin rani,” said a respondent. The study discovered the emergence of new occupation that involves selling of sand at the river bank. The study witnessed conflict between the sand hawkers and land owners who protested about slope failure as the sand is removed. Similar pattern of responses were received at a point near Yarimawa town. Sugar cane cultivation ceased to exist due to moisture deficiency which prior to the dam project was an important source of income for the people. Indeed, the people were reluctant to cooperate with the researcher as they thought he was an agent of the Government, coming to tease them. It was when the researcher explained the true position that they agreed to respond. Table 4 is a summary of the people’s view around station 3.

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PLATE 2: SAND SELLERS AGGRAVATING EROSION IN THE WATARI RIVERBANK Source: Field work 2009 . Table 4: Comparative view of pre-and post dam situation at station 3 Effective period Ordinal status % of respondents

Pre dam income status Good 98.3 Post dam income status Extremely bad 89.7 Positive effects of the Dam Nil 88.4

Negative effects of the Dam Numerous 99.8

General opinion on the project Need water flow in the dry season 82.5 Source: field work 2009

From the table it is seen that over 98% prefers the pre dam situation by describing it as good in terms of income and their general wellbeing. Similarly it is almost a unanimous (89%) objection to the damming as the respondents described the project as extremely poor in terms of their

dry season farming. In the opinion of all (99.8) proposed that the negative effects of the damming are uncountable. At least 82.5% hold the view that they need water to flow during the dry season for domestic and dry season farming.

Table 5: Temporal variation in cropping pattern at station 3 Prevailing event Major crop Percentage

Pre dam cultivation Sugar cane 89.5 Post dam cultivation Guinea corn 94.1 Major changes Cash to food crop 98.6 Source: field work 2009 During an interview at Yarimawa, the researcher asked the reason for abandoning sugar cane cultivation. The response was so sorrowful that one elder person broke in to tears lamenting: “we have nobody in the Government that is why we are made slaves. Our villages are declining living old people and children. In every house you see some are far away on cin rani. This situation is affecting our way of living”. After that the man refused to talk any more, tears kept rolling down his cheeks.

Comparing the pre dam situation as disclosed by the respondents, the present

condition is pathetic. In the past, traditional Sakia and Jigo systems were used for dry season farming but now the downstream area is too dry due to lowering of water table. The study discovered that only rich farmers that can afford pumping machine and tube wells can participate in dry season cultivation. Majority of those found using bore holes are wealthy people who came from far places to rent land. The landlords can only collect the rent and work in the farms as labourers. Table 6 illustrates the change in occupation as at the time of the study.

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TABLE 6 : FARMING AND LAND TENURE SITUATION S/N0 Occupation Status Percentage

1 Farming Tenant 76.8 2 Sell of vegetables Indigene 6.3 3 Up loading works Indigene 8.9 4 Landlord and farmer Indigene 8.0 Source: Field work 2009

The table shows about 76.8% are tenant farmers. These are presumed to be mainly landlords turned to tenants/labourers on their own land. The landlords engaged in farming who own the land are quite insignificant, barely 8%. Those that cannot work as labourers are engaged in selling vegetables, as middlemen, up loading or embark on seasonal migration to urban areas. The study discovered a kind of marginalised economy prevailing in the area. Further research is needed on the socio economic situation of the damming. Issues like the fate of the nomads and their cattle as well as grazing land need an intensive study as well.

CONCLUSION AND RECOMMENDATIONS Damming has brought about the dryness of the river bed exposing the fine texture sand to its preys. Trucks, pick ups and tippers are used to convey the sand to construction sites in the metropolitan Kano and other nearby areas. This has led to slope failures, destruction of farm lands and trees as well as the collapse of river banks at the Banks. Many farmers claimed to have lost the whole farm land. It was discovered during the study that Bagwai and Tofa LGC’s have passed bills against digging sand in their area due to agitation by farmers.

PLATE 3: THE EFFECT OF DIGGING OF SAND AT THE RIVER BANK SOURCE FIELD WORK 2009

It can be concluded that the dam project only benefited the immediate vicinity of the dam environment. The further away one moves from the dam the drier the land and the less productive the area. The rate of rural – urban migration is very alarming, where active youth are leaving the place from temporary to permanent migration. Cultivation of cash crop such as sugar cane is no longer possible and even the vegetable cultivation is taken over by rich people who can afford bore holes and pumping machines instead of the pre-dam method of Jigo and Sakia system. Joblessness and low income aggravate the people’s temperament. The project only assists the

immediate dam vicinity but affected the downstream negatively. It led to increased poverty of the downstream community

It is recommended that distributive justice be done to the downstream environment to alleviate their suffering. To this end, there should be release of the water during the dry season, to supply the needed moisture for cultivation and stop the sand trading syndrome. Overflow of the dam during rain fall peak should be averted to check the undue damage to their rainy season crops. The observed pattern of migration should be addressed to discourage further drift through the creation of employment and income generation services.

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REFERENCES Agbonoga, J.E. (1995): Resources Exploration and

Environmental Degradation. The case study of Bendel Cement Company Activities in Okpella Clan; A Paper Presented at 6th Annual Conference of Environment and Behaviour Association of Nigeria, held at O.A. U, Ille ife.

Abdulkadir, A. (1984). The Properties and Agricultural Potential of Soil of the Southern Lake Chad Area.

Adnan, A. (2009). Assessment of Underground Water and Aquifer Vulnerability in the Kano Region; an unpublished Ph.D Thesis at Department of Geography Bayero University Kano.

Baba J.M. (1984). “Developing Rural Nigeria, Capital Intensive irrigation Project: A critique”, Journal of Issues and Development Vol. 1, No 1 pp 1-15

Babajide, D. M. (1984). ‘Post Irrigation Assessment in Thomas Area’, Unpublished M.Sc Thesis (Land Resource) B.U.K.

Buba L.F. (1992). ‘Rainfall Variability in Northern Nigeria’ Paper presented at 36th Annual

Conference of the Nigerian Geographical Association, Sokoto Nigeria. Area Kano State, Unpublished M.Sc Thesis (Land Resource) B.U.K.

Chorley R.J. (1991). Water, Earth and Man, London Mathum & Co Ltd.

Clark R. (1985). Water: The International Crisis, Evathscan Publication Ltd London

Daniel, M. P. (1985). Post Irrigation Assessment of Soil Nutrients Status in Thomas River Project

Ega, L.A. (1984). “Implication of the 1987 Land Use Act for Agricultural Development in Nigeria” Journal of Issues in Development Vol 1, No 2 pp 6 - 12

Ejiofor, P.N.O (1978). “The Case for Modernization of Agriculture in Nigeria; A Social Science Approach, Paper Presented at N.G.A. Conference, A.B.U. Zaria.

Falola, J.A. (1986). Land and Water rights in Kinsingin Rehabilitated Fadama, Kano State: Crisis and its Resolution, Paper for 31st Annual Conference of the NGA, Port-Harcourt April 1988.

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NITROGEN ACCUMULATION AND PARTITIONING IN A CEREAL - LEGUME INTERCROPPING

Daraja, Y.B. Department of Crop Science, Kano University of Science and Technology, Wudil

ABSTRACT Field intercropping experiments involving wheat and faba bean over two years and under additive and replacement designs, were assessed for the capture and partitioning of nitrogen (N). Intercropping reduced the uptake and recovery of N in the wheat and the bean components. Late-season N uptake in wheat was reduced by intercropping under low N availability. The contribution of remobilized N to wheat grain N ranged from 46% to 100% depending on the severity of the intercropping effect. For sowings with high available soil N, the effect of intercropping depended on the intercropping design; in the replacement design the reduction in N recovery was due to impaired remobilization of N, while in the additive design the reduction was associated with effects on late-season uptake. Faba bean dominated the performance of the intercrop contributing 63% to 95% of the intercrop grain N. Total grain N recovery did not exceed that of sole-crop beans despite attaining LER values greater than 1.

Key words: Faba bean, intercropping, nitrogen remobilization, wheat INTRODUCTION Nitrogen (N) is the most important fertilizer element affecting the quality and productivity of wheat and is a major component of proteins and enzymes (Gooding and Davies, 1997). It is strongly correlated with canopy size and duration, light interception, grain numbers per unit area and grain yield (Sylvester-Bradley et al., 1997). Nitrogen application also regularly increases grain protein content (Gooding et al., 2007). The principal source of N for cereal grains is N remobilized from senescing plant vegetative tissues (Simpson et al., 1983) and many authors have reported that the contribution of remobilized N to grain N is about 60-92% (e.g. Cox et al., 1985; Papakosta and Gagianas, 1991). The quantity of N available for partitioning to the grain can be estimated from the amount accumulated by the plant prior to flowering (Cox et al., 1986) which is also a function of soil N supply (Papakosta and Gagianas, 1991), the genotype (Cox et al., 1985), and diseases (Gooding et al., 2005).

Intercropping cereals with legumes is claimed to be more efficient at resource capture and utilization compared to sole-crops (Ghaley et al., 2005). Such advantages for N utilization have been reported for wheat- faba bean intercrops (Bulson et al., 1997; Gooding et al., 2007). Legumes such as faba bean normally obtain their N requirement by fixing atmospheric N through symbiotic fixation by association with Rhizobium bacteria (Jensen, 1996) which reduces their dependence on inorganic fertilizer N application. The wheat crop, however, does not have such ability to access atmospheric N and, must depend solely on external sources for their supply. Therefore, competition for available soil N can be reduced when cereals and legumes are grown together (Morgado and Willey, 2003). Achieving sufficient grain protein concentration is a particular challenge in organic systems where the application of chemical fertilizer is curtailed.

Low protein concentration in grain often limits the suitability of wheat grown organically for pan bread production. This deficiency is indicative of systems that are significantly limited by N availability, especially during grain filling (Berry et al. 2002; David et al. 2005). The present study describes results from replicated and repeated field experiments to further clarify the uptake and remobilization of N in wheat and faba bean intercropping. The study involved both additive and replacement intercropping designs and two contrasting management systems i.e. conventional and organic systems. MATERIALS AND METHODS Experiment 1 comprised spring and autumn sowing under organic management system, each repeated in the 2005/06 and 2006/07 growing seasons. All four sowings comprised a replacement series in wheat: bean proportions of 100:0, 75:25, 50:50, 25:75, 0:100, where 100% wheat was 400 seeds/m2 and 100% beans was 32 seeds/m2 for winter sowing and 52 seeds/m2 for spring sowing. Cultivars used in the experiments were Malacca wheat and Clipper beans for autumn sowing, and Paragon wheat and Meli beans for spring sowing. Plots were 2 x 10m and treatments were randomized in four blocks.

Experiment 2 comprised four blocks in a split-split plot design divided into sulphur-treatment main-plots, divided into wheat seed rate plots, which themselves were divided into bean treatment sub plots. Wheat (cv. Malacca) seed rates were 0, 10, 50, 100, 200 seeds/m2; the bean (cv. Clipper) treatments were with or without 40 bean seeds/m2 applied at GS31 (Zadoks et al., 1974). Two of the blocks were placed on land managed organically. The remaining two blocks were managed conventionally. In the conventional area ammonium nitrate was applied to supply a total of 100 kg N/ha.

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Measurements Destructive samples (1m x 0.5m) were taken at various growth stages (GS 25, 32, 69 and maturity). At each of the first three samplings, plants were separated into wheat, beans and dried in an oven for 48 hours at 80ºC to determine dry matter. The dried samples were milled and N analysed after oxidative combustion (Kowalenko 2004, AOAC International 2005) using a Leco FP-528 (Leco Instruments (UK) Ltd., Cheshire) respectively. The samples at maturity were separated into stems, leaf sheath and ears (or pods for beans) and were oven dried for 48 hours at 80ºC and weighed separately. The ears and pods were threshed and separated into grains and chaff. The chaff was added to the plant materials and milled while the grains were milled using a Laboratory Mill 3100 (Perten instruments AB, Huddinge, Sweden). The milled plant materials and grains were used to analyse for N as described previously. RESULTS The low nitrogen availabilities of the sowings in Experiment 1 resulted in very low nitrogen recoveries in the above ground, sole-crop wheat, only averaging less than 40kg N/ha. Intercropping wheat with beans reduced the amount of nitrogen in the above ground biomass of wheat, but this was mostly due to effects on post-anthesis uptake rather than on amounts accumulated by flowering (Table 1). Intercropping had no effect on the amounts of nitrogen disappearing from the non-grain tissues after anthesis. Reduced nitrogen quantity in the grains appeared, therefore, to be due to reduced late-season uptake, rather than impaired remobilization. If it is assumed that all N disappearing from the non-grain tissues after anthesis is partitioned to the grain, the contribution of remobilised N to grain N was increased from 61% in the sole-cropped wheat to

79% in the intercropped wheat. The amount of nitrogen accumulated above-ground by the beans was reduced by intercropping, both before and after anthesis of the wheat (Table 1). Grain N appeared to be reduced by intercropping because of both reduced late season uptake and partitioning. As with wheat, however, intercropping appeared to render grain N more dependent on remobilised N (67%) than for the sole-cropped beans (47%).Taken as a whole, the nitrogen accumulation and partitioning for the intercrop was dominated by the performance of the beans. The beans contributed 74% of the grain N in the intercrop. Nitrogen recovery of the intercrop was always lower than that from the sole-cropped beans.

It appeared that much more nitrogen was available in Experiment 2 than in the previous sowings, with above-ground, sole-crop wheat at 200 seeds/m2 recovering 114 and 186 kg N/ha in the conventional and organic areas respectively. As in the replacement intercrops for Experiment 1, adding beans to the wheat significantly reduced recoveries of nitrogen by the wheat in both the non-grain (Fig.1i,j) and grain (Fig. 1e,f) components as indicated by significant (p<0.05) effects of beans and beans x wheat seed rate (Fig. 1). There was no effect of seed rate (Fig. 1m) on nitrogen harvest index. In contrast to Experiment 1, intercropping increased the amount of nitrogen in the grain of the intercrop (wheat + beans), compared to that which was achieved with sole-crop beans, as indicated by a significant effect of wheat seed rate (Fig 1h, p<0.001 for linear effect). This was, in part, associated with improved nitrogen harvest index as seed rates increased (Fig. 1p; p<0.001), and also because nitrogen in the beans was not reduced by intercropping (Fig. 1g). However, intercropping did not increase grain nitrogen yields compared to the sole-crop wheat at the highest seed rate (Fig.1e, h).

Table 1 Effects of intercropping on N uptake and partitioning (kg/ha) in wheat and faba bean. Values are means from autumn and spring sowings in each of the 2005/06 and 2006/07 growing seasons in Experiment 1. Intercrop values are means for all intercrop combinations.

Wheat Beans Intercrop total

Sole crop

Inter-crop

SED 41 df

Sole crop

Inter-crop

SED 41 df

SED 41 df

Replicates

16 48 16 48 48

Above ground N at anthesis (N

a)

29.7 26.0 2.02 104.4 52.5 7.49 78.5 7.16

Above ground N at harvest (N

h)

37.9 29.2 1.98 161.0 67.6 8.35 96.8 8.20

Late N uptake (Nh-N

a) 8.2 3.3 2.34 56.6 15.1 9.61 18.4 9.76

Grain N at harvest (Ng) 20.9 15.8 1.15 106.6 43.9 6.69 59.7 6.48

Vegetative N at harvest (N

v)

17.0 13.5 1.33 54.4 23.7 5.75 37.2 7.99

‘Remobilised N’ (Na-(N

v) 12.7 12.5 2.23 50.0 28.9 8.21 41.4 4.50

N harvest index 100.Ng/N

h 61.2 60.4 1.38 66.4 63.9 1.68 63.0 1.59

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Figure 1. The effect of adding faba bean at the start of stem extension, to different sowing densities of wheat on the yields and partitioning of nitrogen within and between the two crop species at harvest. Vertical bars are SEDs for comparing bean treatments at the same sowing density.

DISCUSSION The contribution of N assimilated prior to anthesis to the total N uptake by wheat at maturity in this study ranges from 67% to 90% and is consistent with the report of previous studies (Cox et al., 1985; Papakosta and Gagianas, 1991; Muurinen et al., 2007). Consistent with Gooding et al. (2007), it was demonstrated in the present study that intercropping reduced the recovery of nitrogen in the above-ground biomass of wheat and subsequently the recovery of nitrogen in the wheat grain. However, the mechanism of the reduction by intercropping varied with the system investigated; possibly because organic and low input systems may have different seasonal N cycling and availability than conventional systems (Dawson et al., 2008). In Experiment 1 with very low N availability in the

organic system, the reduction of N recovery in the wheat grain was due to intercropping effect on post-anthesis uptake rather than effects on pre-anthesis accumulation which is not surprising given that the available N in the soil may have been exhausted by grain filling and also because of the resulting inter-specific competition for the dwindling available soil N. Intercropping, therefore, rendered wheat more reliant on remobilized N accumulated in vegetative tissues by anthesis.

For Experiment 2, there was a high N availability but intercropping still reduced the above-ground accumulation of N by the wheat. The reductions were associated with the dominance of faba beans which restricted the NHI of the wheat possibly because of application of sulphur.

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Indeed previous studies have demonstrated the positive effect of S on the N-fixing apparatus of legumes. Zhao et al. (1999) and Andersen et al. (2007) have shown the increased impact of inter-specific competition from the legume component of their study due to S application.

This study has shown that the performance of the intercrop in terms of accumulation and recovery of N was dominated by the faba bean. In agreement with Bulson et al. (1997), it was demonstrated that the total (wheat + beans) N recovery was lower than that achieved by sole-crop beans. Previous attempts over six replacement intercropping experiments failed to improve intercrop N yields/ha over sole-crop beans at the same site involving wheat and faba bean .This was despite intercropping advantage i.e. land equivalent ratio (LER) values being greater than unity for N) in those experiments and in the present study. The

LER values (ranging from 1.11 to 1.66) indicated that there was a high complementarity for N in the intercrop. Despite this, intercropping was able to achieve higher grain N yield than the bean sole-crop in Experiment 2 associated with improved nitrogen harvest index as the wheat seed rate rises and, also because intercropping did not reduce bean grain N yield. The intercrop was however unable to achieve higher grain N than wheat sole-crop.

CONCLUSION This study has demonstrated that intercropping can reduce the wheat grain N accumulation and, hence grain protein concentration, with implication for end-use quality such as pan bread production. The adoption of organic and/or intercropping system in wheat production by farmers (with its reported advantages) would, therefore, have to be weighed against possible reduction in wheat grain quality.

REFERENCES Andersen, M.K., Hauggaard-Nielsen, H., Hogh-

Jensen, H. A., Jensen, E.S. (2007). Competition for and utilization of sulphur in sole and intercrops of pea and barley. Nutrient Cycling in Agroecosystems 77, 143-153.

Berry, P.M., Sylvester-Bradley, R., Phillips, L., Hatch, D.J., Cuttle, S.P., Rayns, F.W., Gosling, P. (2002). Is the productivity of organic farms restricted by supply of available nitrogen? Soil Use and Management 18 (Supplement), 248-255.

Bulson, H.A.J., Snaydon, R.W., Stopes, C.E. (1997). Effect of plant density on intercropped wheat and field beans in an organic farming system. Journal of Agricultural Science, Cambridge 128, 59-71.

Cox, M.C., Qualset, C.O., Rains, D.W. (1985a). Genetic variation for nitrogen assimilation and translocation in wheat.I. Dry matter and nitrogen accumulation. Crop Science 25, 430-435.

Cox, M.C., Qualset, C.O., Rains, D.W. (1986). Genetic variation for nitrogen assimilation and translocation in wheat.III. Nitrogen translocation in relation to grain yield and protein. Crop Science 26, 737-740.

David, C., Jeuffroy, M.H., Laurent, M., Mangin, A., Meynard, J.M. (2005). The assessment of AZODYN-ORG model managing nitrogen fertilization of organic winter wheat. European Journal of Agronomy 23, 225-242.

Dawson, J.C., Huggings, D.R., Jones, S.S. (2008). Characterizing nitrogen use efficiency in natural and agricultural ecosystems to improve the performance of cereal crops in low-input and organic agricultural systems. Field Crops Research 107, 89-101.

Ghaley, B.B., Hauggaard-Nielsen, H., Hogh-Jensen, H., Jensen, E.S. (2005). Intercropping of wheat and peas as influenced by nitrogen fertilization. Nutrient Cycling in Agroecosystems 73, 201-212.

Gooding, M.J., Davies, W.P. (1997). Wheat Production and Utilization – Systems, Quality and the Environment. CAB International Publications.

Gooding, M.J., Gregory, P.J., Ford, K.E., Pepler, S. (2005). Fungicide and cultivar affect post-anthesis patterns of nitrogen uptake, remobilization and utilization efficiency in wheat. Journal of Agricultural Science, 143, 503-518.

Gooding, M.J., Kasyanova, E., Ruske, R., Hauggaard-Nielsen, H., Jensen, E.S., Dahlmann, C., Von Frangstein, P., Dibet, A., Corre-Hellou, G., Crozat, Y., Pristeri, A., Romeo, M., Monti, M., Launay, M. (2007). Intercropping with pulses to concentrate nitrogen and sulphur in wheat. Journal of Agricultural Science 145, 1-11.

Jensen, E.S. (1996). Grain yield, symbiotic nitrogen fixation and interspecific competition for inorganic N in pea-barley intercrops. Plant and Soil 182, 25-38.

Morgado, L.B., Willey, R.W. (2003). Effects of plant population and nitrogen fertilizer on yield and efficiency of maize-bean intercropping. Pesquisa Agropecuaria Brasileira 38, 1257-1264.

Muurinen, S., Kleemola, J., Peltonen-Sainio, P. (2007). Accumulation and translocation of nitrogen in spring cereal cultivars differing in nitrogen use efficiency. Agronomy Journal 99, 441-449.

Papakosta, D.K., Gagianas, A.A. (1991). Nitrogen and dry matter accumulation, remobilization and losses for Mediterranean wheat during grain filling. Agronomy Journal 83, 864-870.

Simpson, R.J., Lambers, H., Dalling, M.J. (1983). Nitrogen redistribution during grain growth in wheat. Plant Physiology 71, 7-14.

Sylvester-Bradley, R., Scott, R.K., Stokes, D.T., Clare, R.W. (1997). The significance of crop canopies for N nutrition. Optimising Cereal inputs; Its scientific Basis. Aspects of Applied Biology 50, 103-116.

Zadoks, J.C., Chang, T.T., Konnzak, C.F.(1974). A decimal code for growth stages of cereals. Weed Research 14, 415-421.

Zhao, F.J., Hawkesford, M.J., Mcgrath, S.P. (1999a). Sulphur assimilation and effects on yield and quality of wheat. Journal of Cereal Science 30, 1-17.

EFFECT OF SULPHUR NUTRITION ON DRY MATTER AND GRAIN YIELD IN WHEAT AND FABA BEAN INTERCROPPING

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Daraja, Y.B. Department of Crop Science, Kano University of Science and Technology, Wudil

ABSTRACT The sulphur (S) nutrition in wheat: faba bean intercropping, involving additive and replacement designs, in conventional and organic systems, were studied in field experiments in the 2005/2006 and 2006/2007 growing seasons. Intercropping reduced wheat grain yield by about 26%. The application of S reduced wheat grain yield in the intercrop associated with increased competition from faba bean. The experiment and system context influenced the species composition of the intercrops and S application was associated with a reduction in wheat: bean ratio in all experiments i.e. S increased the yields of beans relative to yields of wheat. There was an intercropping advantage for grain DM and S yield as shown by LER values being substantially greater than unity.

Key words: Faba bean, intercropping, sulphur, Wheat

INTRODUCTION Intercropping i.e. growing more than one crop in the same area at the same time (Willey, 1979; Ofori and Stern, 1987) is suited to low input crop production systems where it can help stabilize total yield through complementary and more efficient utilization of resources (Corre-Hellou and Crozat, 2005). In particular, intercropping cereals with legumes may: produce a yield advantage over the component sole crops (Bulson et al., 1997; Hauggaard-Nielsen et al., 2008) and reduce the need for chemical fertilizer nitrogen (Knudsen et al., 2004). Bulson et al. (1997) and Haymes and Lee, (1999) have demonstrated a clear yield advantage for wheat plus faba bean intercropping associated with improved land utilization efficiency, weed suppression and complementary use of resources.

The nitrogen and sulphur nutrition of wheat is well understood (Zhao et al., 1999). However, the nitrogen nutrition of faba bean is more complicated due to the additional factor of symbiotic nitrogen fixation with Rhizobia (Jensen, 1986). This ability may help reduce competition for nitrogen with the associated cereals (Morgado and Willey, 2003) but, legumes still have a significant requirement for sulphur. Sulphur deficiency was rare until recently, although the essential role of sulphur for plant growth has been recognized for a long time (Zhao et al., 1999). This study was undertaken to further understand the effects of sulphur fertilization on the dry matter accumulation and yield of the component crops in wheat - faba bean intercropping.

MATERIALS AND METHODS Field experiments involving wheat and faba bean intercropping were carried out at the Crops Research Unit, University of Reading (0°54’W, 51°29’N) over two seasons ( 2005/06 and 2006/07) on a free-draining sandy loam overlying coarse red-brown sand, from the Sonning series (Jarvis 1968).

Experimental design The experiment comprised four blocks (20m x 20m) in a split-split plot design divided into sulphur-treatment main-plots (10m x 20m), further divided into wheat seed rate plots (10m x 4m), which themselves were divided into bean treatment sub plots (10m x 2m). Wheat (cv. Malacca) seed rates were 0, 10, 50, 100, 200 seeds/m2; the bean (cv. Clipper) treatments were with or without 40 bean seeds/m2; and sulphur treatments were with and without 40 kg SO

3/ha

applied at GS31 (Zadoks et al., 1974). Two of the blocks were placed on land managed organically. The remaining two blocks were managed conventionally. In the conventional area S was applied as ammonium sulphate with additional ammonium nitrate to supply a total of 100 kg N/ha. The without S treatment received 100 kg N/ha as ammonium nitrate. In the organic area, S was applied as elemental sulphur. Measurements Destructive samples (1m x 0.5m) were taken at various growth stages (GS 25, 32, 69 and maturity). At each of the first three samplings, plants were separated into wheat, beans and weeds and dried in an oven for 48 hours at 80ºC to determine dry matter. The dried samples were milled and S analysed after oxidative combustion (Kowalenko 2004, AOAC International 2005) using a Leco SC-144DR (Leco Instruments (UK) Ltd., Cheshire) respectively. The samples at maturity were separated into stems, leaf sheath and ears (or pods for beans) and were oven dried for 48 hours at 80ºC and weighed separately. The ears and pods were threshed and separated into grains and chaff. The chaff was added to the plant materials and milled while the grains were milled using a Laboratory Mill 3100 (Perten instruments AB, Huddinge, Sweden). The milled plant materials and grains were used to analyse for S as described previously.

Statistical analyses Data was subjected to appropriate factorial and split-plot analyses of variance using GENSTAT 10. Polynomial regressions were fitted across wheat seed rate levels using orthogonal polynomial

contrasts in the analyses of variance. Where deviations from linearity were significant (p<0.05), asymptotic responses to wheat seed rate (sr) were assessed for suitability in comparison to quadratic or cubic fits (Gooding et

126


al., 2002). Analysis of variance on wheat or bean measurements were restricted to plots where the crops were sown to avoid generating treatment means of zero.

RESULTS AND DISCUSSION The experiment and system contexts played a large role in determining species composition of the intercrops. Judging from the grain yields (Table 1) when sulphur was not applied wheat and beans were in broad equivalence in the conventional parts, while wheat dominated beans in the organic blocks. In all experiment x system comparisons, sulphur application was associated with a reduction in the wheat: bean ratio, i.e. increased the yield of beans relative to yield of wheat.

There was a small but statistically significant sulphur x wheat seed rate interaction (p=0.038) on wheat dry matter at flag leaf emergence. Wheat dry matter increased with seed rate but the interaction arose mainly because at the highest seed rate, sulphur significantly reduced wheat dry matter (Fig.1a and b). There was also a sulphur x wheat seed

rate interaction on bean dry matter (p=0.047), but in contrast to that on wheat, the interaction was positive i.e. sulphur increased dry matter yield of beans at the highest wheat seed rate (Fig. 1c). By maturity the negative sulphur x wheat seed rate interaction on wheat dry matter was no longer statistically significant (p=0.133) but there was a strong negative effect of beans on wheat dry matter (p=0.001). The bean dry matter continued to reveal a positive sulphur x wheat seed rate interaction (p= 0.004) i.e. sulphur increased bean dry matter, particularly so at the highest wheat seed rate (Fig.1g). For total dry matter, neither sulphur nor sulphur x wheat seed rate effects was significant (Fig. 1 h).

There was a sulphur x bean interaction (p=0.038) for wheat harvest index. There was no effect of seed rate, or in the absence of bean, an effect of sulphur (Fig. 1i). However, the presence of both beans and sulphur reduced wheat harvest index (Fig.1j). The bean harvest index was not affected by sulphur treatment (Fig. 1k). For the total harvest index, there was a positive linear seed rate effect (p=0.002) (Fig. 1l).

Table 1: Effect of system, experiment and S application on the grain yield of wheat: faba bean intercrops. Values are mean grain yields in kg/ha.

System Crop Sulphur Grain yield

Conventional Wheat - 1359 Wheat + 605 SED (8 d.f.) 242

Bean - 1404 Bean + 1742 SED (9 d.f.) 143

Organic Wheat _ 1450 Wheat + 1198 SED (8 d.f.) 399 Bean - 673 Bean + 587 SED (9 d.f.) 131

The negative interaction between sulphur and wheat seed rate on wheat was again evidenced on combine harvested wheat grain yield (p=0.027). There was also a wheat seed rate x bean effect (p=0.011). Sulphur did not significantly affect grain yield in the sole crop wheat (Fig. 1q). Addition of bean to the wheat however, significantly reduced wheat grain yield (Figs. 1q and 1r). Within the intercropped wheat, application of sulphur significantly reduced grain yield especially at the highest wheat seed rate (Fig.1r). The bean grain yield revealed a sulphur x wheat seed rate effect (p=0.048). In contrast to the negative effect of sulphur on wheat grain yield, addition of sulphur increased bean grain yield at the two highest wheat seed rates (Fig.

1s). Overall, the wheat plus bean grain yield was not influenced by sulphur, but there was a positive linear wheat seed rate main effect (p=0.001) (Fig 1t).

The current results are consistent with previous studies demonstrating that intercropping cereals with grain legumes can reduce the cereal grain yield (Bulson et al., 1997, Gooding et al., 2007), but it was also shown that this effect was evident even at early growth stages. Increases in sole-crop wheat yields in response to sulphur application have been established (McGrath et al., 1996; Withers et al.,1997; Zhao et al., 1999; De Ruiter and Martin, 2001).

Our study, however, demonstrates that sulphur application can reduce wheat grain yield in intercrops. The effect of sulphur on faba bean grain yield was inconsistent, but the bean grain yield was significantly increased by sulphur application in the

conventional sowings. It has been demonstrated by other workers (Pacyna et al., 2006; Scherer et al., 2008) that sulphur increased the nodule yield formation, the shoot yield and to a lesser extent the root yield of legume crops. They also showed that

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sulphur increased the nitrogen fixation of legumes through effects on root nodule bacteria and nitrogenase. Indeed, these effects were specifically demonstrated for faba bean by El Sheikh and El Zidani (1997) and Habtemichial et al. (2007). In addition, Andersen et al. (2007) have demonstrated in a barley-pea intercrop that the pea component dominated the barley due to enhanced nitrogen fixation brought about by sulphur addition and that,

this was a central competitive asset in crop dynamics in cereal-legume intercrops. This is consistent with our findings that sulphur application was associated with a reduction in the wheat: bean ratio i.e. sulphur increased the yield of beans relative to yield of wheat. The reduced wheat grain yield in the intercrop therefore, can be attributed to enhanced competition from the associated faba bean crop.

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Figure 1. The effect of adding faba bean and sulphur to different wheat sowing densities in a winter wheat and faba bean intercrop, on the dry matter accumulation, grain yield and harvest index within and between component species. Vertical lines are SEDs for comparing different levels of S at the same wheat seed rate. Open squares= no sulphur applied, closed squares= sulphur applied.

CONCLUSION In conclusion, it was demonstrated in the present study that sulphur can decrease wheat grain yield in the intercrop and increase that of faba bean.

As a result, sulphur application was associated with a reduction in wheat: faba bean ratio and, thus affected the composition and balance between intercrop components.

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REFERENCES ANDERSEN, M.K., HAUGGAARD-NIELSEN, H., HOGH-

JENSEN, H. A., JENSEN, E.S. (2007). Competition for and utilization of sulphur in sole and intercrops of pea and barley. Nutrient Cycling in Agroecosystems 77, 143-153.

AOAC INTERNATIONAL (2005). Official method 992.23 Crude protein in cereal grains and oilseeds. In Howitz, W. and Latimer, G. (Eds.) Official Methods of Analysis of AOAC international, 18th edn. AOAC International. Gaithersburg, M.D.

BULSON, H.A.J., SNAYDON, R.W., STOPES, C.E. (1997). Effect of plant density on intercropped wheat and field beans in an organic farming system. Journal of Agricultural Science, Cambridge 128, 59-71.

CORRE-HELLOU, G., CROZAT, Y. (2005). Assessment of root system dynamics of species grown in mixtures under field conditions using herbicide injection and 15N natural abundance method: a case study with pea, barley and mustard. Plant and Soil 276, 177-192.

DE RUITER, J.W., MARTIN, R.J. (2001). Management of nitrogen and sulphur fertilizer for improved bread wheat (Triticum aestivum) quality. New Zealand Journal of Crop and Horticultural Science 29, 287-299.

EL-SHEIKH, E.A.E., EL-ZIDANY, A.A. (1997). Effects of rhizobium inoculation and chemical fertilizers on yield and physical properties of faba bean seeds. Plant Foods for Human Nutrition 51, 137-144.

GOODING, M.J., PINYOSINWAT, A., ELLIS, R.H. (2002). Responses of wheat grain yield and quality to seed rate. Journal of Agricultural Science 138, 317-331.

GOODING, M.J., KASYANOVA, E., RUSKE, R., HAUGGAARD-NIELSEN, H., JENSEN, E.S., DAHLMANN, C., VON FRANGSTEIN, P., DIBET, A., CORRE-HELLOU, G., CROZAT, Y., PRISTERI, A., ROMEO, M., MONTI, M., LAUNAY, M. (2007). Intercropping with pulses to concentrate nitrogen and sulphur in wheat. Journal of Agricultural Science 145, 1-11.

HABTEMICHIAL, K.H., SINGH, B.R., AUNE, J.B. (2007). Wheat response to N-2 fixed by faba bean (Vicia faba L.) as affected by sulphur fertilization and rhizobial inoculation in semi-arid Northern Ethiopia. Journal of Plant Nutrition and Soil Science 170, 412-418.

HAYMES, R., LEE, H.C. (1999). Competition between autumn and spring planted grain intercrops of wheat and field bean. Field Crops Research 62, 167-176.

HAUGGAARD-NIELSEN, H., JORNSGAARD, B., KINANE, J., JENSEN, E.S. 2008. Grain legume-cereal intercropping: The practical application of diversity, competition and facilitation in arable and organic systems. Renewable Agriculture and Food Systems 23, 3-12.

JARVIS, R.A. (1968). Soils of the Reading District: Memoirs of the Soil Survey of Great Britain. Rothamsted Experimental Station, Harpenden.

JENSEN, E.S. (1986). Intercropping field bean with spring wheat. Vortrage Fur Flanzenzuchtung 11, 67-75.

KNUDSEN, M.T., HAUGGAARD-NIELSEN, H., JORNSGARD, B., JENSEN, E.S. (2004). Comparison of interspecific competition and N use in pea-barley, faba bean-barley and lupin-barley intercrops grown at two temperate locations. Journal of Agricultural Science 142, 617-627.

KOWALENKO, C.G. (2004). Response of forage grass sulphur application on coastal British Columbia soils. Canadian Journal of Soil Science 84, 227-236.

MCGRATH, S.P., ZHAO, F.J., WITHERS, P.J.A. (1996). Development of sulphur deficiency in crops and its treatment. Proceedings of the Fertilizer Society 379, Peterborough, pp 23-30.

MORGADO, L.B., WILLEY, R.W. (2003). Effects of plant population and nitrogen fertilizer on yield and efficiency of maize-bean intercropping. Pesquisa Agropecuaria Brasileira 38, 1257-1264.

OFORI, F., STERN, W.R. (1987). Cereal-legume intercropping systems. Advances in Agronomy 41, 41-90.

PACYNA, S., SCHULZ, M., SCHERER, H.W. (2006) Influence of sulphur supply on glucose and ATP concentrations of inoculated broad beans (Vicia faba L.). Biology and Fertility of Soils 42, 324–329.

SCHERER, H.W., PACYNA, S., KATRIN, R.P., SCHULZ, M. (2008). Low levels of ferrodoxin, ATP and leghemoglobin contribute to limited N

2

fixation of peas and alfalfa under sulphur deficiency conditions. Biology and Fertility of Soils 44, 909-916.

WILLEY, R.W. (1979). Intercropping: Its importance and research needs. I. Competition and yield advantages. Field Crops Abstracts 32, 1-10

WITHERS, P.J.A., ZHAO, F.J., MCGRATH, S.P., EVANS, E.J., SINCLAIR, A.H. (1997). Sulphur inputs for optimum yields of cereals. In: Gooding, M.J. and Shewry, P.R. (Eds.), Aspects of Applied Biology 50, Optimising Cereal Inputs: Its Scientific Basis, The Association of Applied Biologists, Wellesbourne, UK, pp 191-198.

ZADOKS, J.C., CHANG, T.T., KONNZAK, C.F.(1974). A decimal code for growth stages of cereals. Weed Research 14, 415-421.

ZHAO, F.J., HAWKESFORD, M.J., MCGRATH, S.P. (1999a). Sulphur assimilation and effects on yield and quality of wheat. Journal of Cereal Science 30, 1-17.

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SENSORY EVALUATION OF SOME PROCESSED YOGHURT SOLD IN KANO METROPOLIS, KANO, NIGERIA

Shehu, A.A. Food Science and Technology Department, Faculty of Agriculture and Agricultural Technology, Kano

University of Science and Technology, Wudil. P.M.B 3244, Kano State. Email: [email protected].

ABSTRACT The qualities of some processed yoghurt brands sold in Kano metropolis, Nigeria were evaluated for organoleptic test to determine consumer preference. A total of two hundred samples, twenty (20) each of ten brands of yoghurt namely: Fan, Bimco, Jamil, San, Farm fresh, Farm pride, Amico, Annashuwa, Sunrise and Ultimate were purchased randomly from vendors, provision stores, depots and supermarkets during the months of August and September, 2006. The analysis of variance (ANOVA) was used to analyse the data obtained. Results revealed that the organoleptic characteristics of Bimco yoghurt were more preferred in flavour, texture and overall acceptability while Annashuwa and Ultimate yoghurts were more preferred in taste and consistency respectively and Jamil was the least preferred. The qualities of some yoghurt samples analyzed do not conform to the NAFDAC standards. The organoleptic variations observed with the NAFDAC`s standards indicated the likelihood of poor sanitation and handling procedures during the production, storage and distribution of the yoghurts. The result of this study is of public health concern and calls for effective quality control in yoghurt production by the manufacturers. It is thus recommended that appropriate government regulatory bodies ensure that quality compliance is enforced.

Keywords: Yoghurt, Sensory quality, Kano, Consumer, Preference.

INTRODUCTION Milk is defined as the secretion of the mammary glands of animals which suckle their young ones (Ihekoronye and Ngoddy, 1985). It is an excellent source of nutrients such as proteins, essential amino acids, minerals, vitamins, water, carbohydrate and fat. This also makes it an excellent medium for microbial proliferation (Braddley, 1982). Milk is produced in Nigeria mainly from cow by the Fulanis. Excess fresh cow milk is processed into different products such as “Wara” (West African soft cheese), “Nono” (fermented milk) and yoghurt.

Yoghurt is defined microbiologically as the end product of a controlled fermentation of high solids, whole, skimmed or fortified milk by a symbiotic mixture of Streptococcus thermophilus and Lactobacillus bulgaricus in the ratio of 1:1 (Adams and Moss, 1999).

Yoghurt has been ranked as the most widely available fermented milk product in the world today. Its mild acidic flavour, custard texture coupled with high nutritive value makes it to be among the commonly relished foods throughout the history of mankind (Adams and Moss, 1995).

Production of yoghurt is a classic example of a process employing the beneficial role of some microorganisms. According to Pelczar et al. (1993), S. thermophilus and L. bulgaricus in ratio of 1:1 serve as the starter culture for the transformation of fresh milk to yoghurt under suitable physico-chemical conditions. Beside the starter organisms, yoghurt is not expected to contain other microorganisms beyond certain tolerable limits (FAO, 1979).

There is a need to provide baseline data on the quality of yoghurt sold within Kano metropolis. The data/information would be useful to the yoghurt producers for the improvement and maintenance of the quality of their products. The data would also guide the consumers on the choice of yoghurt brand to buy. The aim of the present study was to determine the sensory qualities of some processed yoghurts sold in Kano metropolis, Nigeria with a view to provide information on the safety of such products for human consumption.

MATERIALS AND METHODS The Study Area Kano metropolis is located between latitude 110

49` and 120 4` north of the equator and longitude 80 31` and 80 40` east of the Greenwich Meridian. Kano metropolis is comprised of six Local government Areas namely: Kano municipal, Gwale, Fagge, Nassarawa, Tarauni and Dala (Fig. 1) (KMLS, 2006). Samples Collection The method of Taura et al (2005) was adopted, in which twenty (20) samples, each of ten (10) most patronized different brands of yoghurt namely: Fan, Bimco, Jamil, San, Farm fresh, Farm pride, Amico, Annashuwa, Sunrise and Ultimate were purchased randomly from supermarkets, vendors and provisions store outlets in Kano metropolis. The samples were transported to the laboratory under aseptic condition in pre-cleaned ice box for analysis.

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Organoleptic evaluation All yoghurt samples were subjected to sensory evaluation using a 5-point hedonic scale (Ihekoronye and Ngoddy, 1985). A sample score sheet was prepared to assess the texture, taste, consistency, flavour and overall acceptability of the samples. In addition, a ten (10) member experienced panel was selected to express their likes or otherwise for each attribute evaluated in the sample score sheet. The data obtained from these subjects were subjected to Analysis of Variance (ANOVA) using Chi-square (X2) test to

determine whether there is a significant difference in the organoleptic properties among the yoghurt brands analyzed (Norman, 1995). Questionnaire Administration Questionnaires on yoghurt preference and associated disease outbreak were randomly administered to 300 respondents. National Agency of Food and Drug Administration Commission (NAFDAC) registration number and expiry dates were analyzed for each brand (Nelly, 2004).

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RESULTS TABLE 1: CONSUMER OPINION ON YOGHURT PREFERENCE AND ASSOCIATED DISEASE OUTBREAK IN KANO METROPOLIS.

S/N Yoghurt brand No. of respondents

Percentage preference (%)

NAFDAC Reg. number

Reported cases of outbreak of disease

Expiry date

1 FAN 38 19 01-5076 - 24-10-2006 2 BIMCO 28 14 01-4359 - 13-10-2006 3 JAMIL 18 09 01-3036 - - 4 SAN 18 09 01-1297L - - 5 FARM FRESH 16 08 - - 31-10-2006 6 FARM PRIDE 16 08 01-5249 - 16-10-2006 7 AMICO 12 06 01-7466 - 15-10-2006 8 ANNASHUWA 12 06 01-5597 - 20-10-2006 9 ULTIMATE 12 06 01-2122L - 20-10-2006 10 SUNRISE 10 05 - - - 11 HASSAN 2 01 X - X 12 MAI DABINO 2 01 X - X 13 USSABA 2 01 X - X 14 WAPA 2 01 X - X 15 HIGHLAND 2 01 X - X 16 BAFFA 2 01 X - X 17 BABBA 2 01 X - X 18 SABCO 2 01 X - X 19 LA-QUISINE 2 01 X - X 20 SUPER 2 01 X - X 21 NAPRI X X X - X 22 NIYYA X X X - X 23 BISSI X X X - X 24 BANANA X X X - X 25 YAZOO X X X - X 26 SANTANA X X X - X 27 HYLLADI X X X - X 28 ALU DAIRY X X X - X 29 ALHERI X X X - X 30 FRESH MILK X X X - X 31 DADIN KOWA X X X - X 32 SHAGALINKU X X X - X 33 HABIB X X X - X 34 LONG LIFE X X X - X 35 DOCTORS X X X - X 36 ALMUNAWWARA X X X - X 37 ASAD X X X - X 38 CLASSIC X X X - X 39 HOME FRESH X X X - X 40 41 42 43 44 45 46 47 48 49 50 51

ALFARMA BRANCO FATIMIYYA RAHAMA NI`IMA ZAMZAM DANFULANI TORANKE HALAL SAAHA ZAINAB RIGHT

X X X X X X X X X X X X



- - - - - - - - - - - -


52 NAGARI X X X - X 53 GAMJI X X X - x 54 JOHNSON X X X - X 55 GOLDEN X X X - X

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Table 1 continue S/N Yoghurt brand No. of

respondents

Percentage preference (%)

NAFDAC Reg. number Reported cases of outbreak of disease

Expiry date

56 AZAMA X X X - X 57 MILKY X X X - X 58 VIJU MILK X X X - X 59 SCIROCCO X X X - X 60 BRIDEL X X X - X 61 OSATA X X X - X 62 JANA X X X - X 63 YUSBOL X X X - X 64 A. A. YOGHURT X X x - X 65 ALWAHADA X X X - X 66 AMANAT X X X - X 67 ALFA X X X - X 68 NAGGE X X X - X 69 SUPREME X X X - X 70 ALL YOGHURT X X X - X Key: - = Nil, X = Not analyzed. Questionnaire The results of yoghurt brand type, brand preference and disease outbreak associated with yoghurt consumption in Kano metropolis showed a total of seventy (70) different brands of yoghurt sold in Kano metropolis. However, 200 responded to the questionnaire as shown in table 1. Out of these, ten (10) are the most patronized with a degree of preference ranging from a maximum of 38 (19%) in Fan yoghurt to a minimum of 10 (5%) in Sunrise. There was no reported disease outbreak associated with any of the brands. Close examination of the 10 brands analyzed revealed that only eight (8) of them have NAFDAC registration number while only seven (7) has expiry date. Sensory Analysis Results of the sensory evaluation of some processed yoghurt brands are presented in Table 2, Flavour ranged between a minimum of 1.5 in Jamil to a maximum of 4.3 in Bimco yoghurt, while taste ranged between a minimum of 1.7 in Jamil and Farm fresh to a maximum of 4.0 in Annashuwa yoghurt. Texture ranged between a minimum of 1.6 in Jamil to a maximum of 4.3 in Bimco yoghurt. The consistency value ranged between a minimum of 1.5 in Jamil to a maximum of 4.3 in Ultimate yoghurt. The overall acceptability ranged between a minimum of 1.7 in Jamil yoghurt to a maximum of 4.5 in Bimco yoghurt. DISCUSSION The survey of consumer preference of yoghurt brands sold in Kano metropolis revealed that some of the yoghurt brands were noted of not having NAFDAC permission to sell their products as well as expiry dates on their pack. This shows

that some of the products were of doubtful quality according to the guidelines of Nduka (2004) and FAO (1979). Hence, there is the need to expedite action towards cautioning the defaulting manufacturers as well as their vendors in line with the requirement of the national agency for food, drug administration and control policy. The good manufacturing practice should also be the main area of concern in the industries so that high quality products can be sold to consumers. It is also a challenge to the environmental and public health superintendents to ensure compliance at all levels. There was no reported disease outbreak associated with any of the brands; this finding support the earlier work conducted by Taura et al, (2005) who also reported that there was no disease outbreak as a result of yoghurt consumption in the study area. From the results of organoleptic evaluation (Table 2) carried out on attributes namely: Flavour, taste, texture, consistency and overall acceptability, it can be seen that sensory evaluations are usually rapid, inexpensive and always complement the exact, impartial laboratory determination, thus, it is a useful tool in the food industries that gives consumers preference for a product (Ihekoronye and Ngoddy, 1985, Adams and Moss, 1999). Results obtained from organoleptic assessment dealing with the organs of taste are subjective and will affect the rating. The results for flavour and taste showed significant difference between all the yoghurt brands (P < 0.05). There was significant difference in the results obtained for texture and consistency for all the yoghurt brands (P < 0.05). Good quality yoghurt should be smooth in appearance and feel smooth in the mouth (Vedamuthu, 1982).

Results obtained from texture showed that Bimco yoghurt had the highest rating while Jamil

yoghurt had the lowest rating. For consistency, Ultimate yoghurt had the highest while Jamil had

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the lowest. Consistency and texture is probably as important as flavour (Vedamuthu, 1982). Bala and Saidu (2005) reported that considerable deviations in organoleptic properties of milk and milk products were usually indicative of defect, which could result into changes in appearance, bad flavor and/or aroma as well as poor consistency. The significant differences obtained from sensory evaluation of the various yoghurt samples could be due to the variation of commercial milk employed in yogurt production and also differences in processing methods (Nelly, 2004).

CONCLUSION AND RECOMMENDATIONS Results obtained from this study showed that many brands of yoghurt were on sale in Kano metropolis. Some brands were of NAFDAC standards and therefore safe for human consumption, others were substandard and this calls for improvement of yoghurt manufacturers. The monitoring of the sanitary conditions of production site as well as organizing seminars and workshops for mobile vendors and other retail agents specifically on environmental and personal hygiene needs to be stressed. Finally, quality control and food safety are a joint responsibility of all manufacturers to ensure that the yoghurt brands are safe for human consumption.

REFERENCES Adams, M.R. and Moss, M.O. (1999). Food

microbiology. 3rd edn. Royal Society of Chemistry, Cambridge UK. pp 252-266.

Bala, J.A. and Saidu,A.D. (2005). Quality evaluation of some processed yoghurt products sold in Kano Metropolis, Kano, Nigeria. B.Sc Thesis (unpublished).

Dept. of Biol. Sci. Bayero University, Kano, Nigeria. 44 pp.

Braddley, R.L. (1982).Milk: In McGraw-Hill encyclopaedia of Science and Technology. 8:559-568. McGraw-Hill Inc. USA.

Food and Agriculture Organisation (FAO, 1979). Manuals of food quality control- Microbiological analysis 14(4): A1-F10. FAO, Food and Nutrition paper, United Nations, Rome, Italy.

Ihekoronye, A.I. and Ngoddy, P.O. (1985). Integrated Food Science and Technology for the Tropics, Macmillan International College Education. New York pp. 106-112, 194-206, 351 pp.

Kano State Ministry of Land and Survey (KMLS, 2006). Map of Kano Metropolitan, On scale 1: 2,500,000.

Nelly, N.O. (2004). A comparative study on microbial quality of commercial and laboratory produced yoghurt. B.Sc thesis (unpublished). Biological Sciences programme, Abubakar Tafawa Balewa University, Bauchi. Pp. 4-55.

Nduka, U. (2004). Public health. Food and industrial microbiology, 3rd ed. BOPECO pub., Benin, Edo, Nigeria, 307 pp.

Norman, T.J.B. (1995). Statistical methods in biology. 3rd edn. Cambridge University Press UK. Pp 61-68.

Pelczar, M.J., Chan, E.C.S., Krieg, N.R. and Edward, D.D. (1993). Microbiology Concepts and applications. 2nd ed. Mc Graw Hill Inc, p 843.

Taura, D. W., Mukhtar, M.D. and Kawo, A.H. (2005). Assessment of microbial Safety of some Brands of yoghurt sold around old campus of Bayero University Kano. Nigerian J. of Microbiol. 19: 1-5

Vedamuthu, E.R. (1982). Fermented Milk pp. 199-223 In: Economic Microbiology Vol. 3. 7th Edition. A.H. Rose, Academic press, London.

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TABLE 2: SENSORY EVALUATION OF SOME PROCESSED YOGHURT BRANDS SOLD IN KANO METROPOLIS ------------------------------------------------------------------------------------------------------------------------------------------------------------------- Yoghurt brands

Sensory Attrib. Fan Bimco Jamil San Farm fresh Farm pride Amico Annashuwa Sunrise Ultimate Total Flavour 2.9a 4.3b 1.5c 3.3d 2.5e 2.3f 3.8g 3.9d 3.8h 4.0i 32.3 Taste 2.9a 3.8b 1.7c 3.2d 1.7e 2.3f 3.9g 4.0d 3.9h 3.9i 31.3 Texture 2.8a 4.3b 1.6c 3.3d 2.5e 3.0f 4.1g 3.9d 3.6h 4.2i 33.3 Consistency 2.8a 4.1b 1.5c 3.3d 2.2e 2.4f 3.8g 4.0d 3.8h 4.3i 32.2 Overall Accept. 3.2a 4.5b 1.7c 3.2d 2.0e 2.4f 4.1g 4.0d 4.0h 4.3i 33.4 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Total 14.6 21.0 8.0 16.3 10.9 12.4 19.7 19.8 19.1 20.7 162.5

Figures with different superscripts are significantly different (P < 0.05).

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