N.E.quest Vol 3 Issue 2 July 2009

Newsletter of North East India Research Forum

N. E. Quest; Volume 3, Issue 2, July 2009. 1



Newsletter Of

NORTH EAST INDIA RESEARCH FORUM

http://tech.groups.yahoo.com/group/northeast_india_research/ www.neindiaresearch.org

97th Indian Science Congress’ 2010

The 97th Indian Science Congress, to be held from January 3 to 7, 2010 would be the Kariavattom campus of the University of Kerala, Trivandrum.

Indian Space Research Organisation (ISRO) and the University of Kerala are hosting the

science congress

The Indian Science Congress will be inaugurated by Prime Minister Manmohan Singh on January 3, 2010. The total number of delegates to participate in the event is expected to touch 7,000, with 5,000-odd delegates coming for the main event and over 1,500 school

students for the National Children’s Science Congress that will be held along with the mega event.

The theme of the Congress would be ‘Science and Technology of 21st century - National

Perspective’. http://isc2010.in:8080/isc/index.jsp



It is the man of science, eager to have his every opinion regenerated, his every idea rationalized, by drinking at the fountain of fact, and devoting all the energies of his life to the cult of truth, not as he understands it, but as he does not yet understand it, that ought properly to be called a philosopher.

~ Charles Peirce Dear Members, It is my proud privilege and honour to be acting as the editor of the NE Quest July 2009 issue. I wish to thank Dr. Adhikari for graciously inviting me for the purpose. On the onset I, on the behalf of the NE India Research Forum, wish to express my heartfelt apologies to the readers for the delay in bringing out this issue due certain unavoidable circumstances. As India transcend with its ambitious goal of transforming as a global superpower, the importance of the north east region has never been so high ever before in realizing this dream. The region can no longer be bogged down with the ills and artificial differences which has long been the bane towards progression. With the huge reserve of untapped bioresources combined with the physical proximity with the ASEAN and APEC countries, and the region need to realize its potential and progress. We need to

explore and reach out to each other to rejuvenate the economy of Northeast with a multi dimensional approach in an integrated manner. The initiatives should include revolutionary changes in priorities to train and develop human resources with the vision of using scientific knowhow for sustainable utilization and commercialization of the natural resources. With steps taken up such as coming together and reaching out under N.E. India Research Forum it is a humble beginning in the right direction. I also wish to thank all the contributors who are graceful enough to submit their informative articles, news items, theses abstracts etc. for this issue. I hope you all continue to do so in future issues too. Thanking you and all the best! (Dr. Thangjam Robert Singh) Assistant Professor Department of Biotechnology Mizoram University

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1. THE FORUM 5

2. SHORT BIOGRAPHY 8

(Birbal Sahni and Meghnath Saha)

3. SCIENCE NEWS 10

4. NORTH EAST INDIANS MADE US PROUD 13

5. MEMBERS IN NEWS, AWARDS /FELLOWSHIP 14

6. INSTRUMENT OF THE ISSUE –Charge – Coupled Devices (CCD) 15 Dr. Abdul Wahab 7. ARTICLES SECTION a) The growth of Intranet: Generations of Intranet 19 Dr. L. Shashikumar Sharma (Guest Article) b) Increasing Zinc Bioavailabity in Food Stuffs of Manipur: A Serious Threat for Health 22 Dr. Kshetrimayum Birla Singh c) Muga silkworm, is it safe in near future 28 Mr. Mahananda Chutia c) On the shape of TL glow curve of bolk ZnS powder 32 Dr. L.Robindro Singh d) Reflection and Refraction of Plane P-Waves at a corrugated interface between 35 liquid –solid half spaces Dr. S. S. Singh e) Lindau: The Nobel Island 42 Mr. Saitanya Kumar Bharadwaj 8. THESIS ABSTRACT a) Synthesis and evaluation of acrylamide polymers for enhancing 45

Petroleum recovery from high temperature subterranean deposit Dr. Anupom Sabhapandit b) Carbon-Carbon bond formation reactions using solid porous catalysts 48 Dr. Pranjal Kalita 9. MEMBER’S FACE 50

10. READER’S PAGE 51

11. HIGHER STUDY ABROAD 53

12. OPPORTUNITIES /ADVERTISEMENTS/CONFERENCES 54

13. THROUGH THE LENSE OF THE MEMBERS 57

(Collage by Mr. Saitanya Kumar Bharadwaj on his Lindau visit)



North East India Research Forum was created on 13

th November 2004.

1. How we are growing. Every forum has to pass through difficult phases at the time of birth. NE India Research Forum is also no exception. At the very beginning, it was a march hardly with few members (from chemistry only) and today the forum comprised of a force of more than 300 elite members. Now we are in a position such that people voluntarily come and join the group irrespective of disciplines.

Graph of no of members w.r.t. months

2. Discussions held in the forum • Necessity of directory of all the

members of the forum. • Possibility of organising conference in

the N. E. India. • Taking initiation on setting up of South

East Asian Scientific Institute. • On selection of Best paper award. • Let us introspect. 3. Poll conducted and results • North East India is lacking behind the

rest of the country due to- 1. Geographical constrain = 0% 2. Bad leadership = 40% 3. Lack of work culture = 36% 4. Corruption = 18% 5. Apathy from Central Govt. = 4%

• Which area of science is going to dominate by creating a great impact on society in next decade?

1. Nanoscience & nanotechnology = 22% 2. Biotechnology = 11% 3. Nanobiotechnology = 38% 4. Chemical Engineering = 0% 5. Medicine = 11% 6. Others = 16% 7. None = 0%

• Kindly let us know your view regarding the following topic. What activities of this group you like most?

1. Research articles = 33% 2.Information about vacancy/positions

available = 10% 3. Way to have a contact with all

members = 29% 4. Scientific discussions = 14% 5. Others = 2%

• Selection of name for Newsletter There were total 36 proposals submitted by members of the forum for the Newsletter. The name proposed by Mr. Abhishek Choudhury, N. E. QUEST received the maximum number of votes and hence it is accepted as the name of the Newsletter. • How often should we publish our

newsletter '' N. E. Quest’’? 1. Every 3 months = 61% 2. Every 6 months = 38% 3. Once a year = 0%

4. Editors of Previous NE-Quest Issues 1. Vol 1 Issue 1 April, 2007 Editor: Dr. Arindam Adhikari 2. Vol 1 Issue 2 July 2007 Editor: Dr. Tankeswar Nath 3. Vol 1 Issue 3 October 2007 Editor: Dr. Ashim Jyoti Thakur 4. Vol 1 Issue 4 January 2008 Editor: Mr. Pranjal Saikia



5. Vol 2 Issue 1 April 2008 Editor: Dr. Sasanka Deka 6. Vol 2 Issue 2 July 2008 Editor: Dr. Rashmi Rekha Devi 7. Vol 2 Issue 3 October 2008 Editor: Dr. Prodeep Phukan 8. Vol 2 Issue 4 January 2009 Editor: Dr. Manab Sharma 9. Vol 3 Issue 1 April 2009 Editor: Dr. Debananda Ningthoujam 10. Vol 3 Issue 2 July 2009 (This issue) Editor: Dr. Robert Singh Thangjam 5. A domain in the name of www.

neindiaresearch.org is booked. 6. Future activities Proper planning and consequent implementation always play an important role in every aspect. Some of the topics / activities / suggestions which were being discussed, time to time in the forum will get top priorities in our future activities. Those are mentioned here, • Preparing complete online database of

N.E. researchers with details. • Organising conference in the N.E.

region-proposed by Dr. Utpal Bora. • Research collaboration among forum

members. • Motivate student to opt for science

education. • Help master’s students in doing

projects in different organisation-proposed by Dr. Khirud Gogoi.

• Supporting schools in rural areas by

different ways. • Best paper awards. • Compilation of book on ‘Education

system of different countries’. Initiative for this project is taken by Dr. Mantu Bhuyan, NEIST, Jorhat, Assam

7. New activity • HiMedia Laboratories Pvt. Ltd is

willing to sponsor some future activities of the forum and have asked for space to advertise their products in the N. E. Quest. Starting this issue (July 2009) N. E. Quest is providing one page for the advertisement. Details about this deal will be informed soon once finalised. Thanks to Dr. Robert Thangjam for his initiative in this matter.

• North East India Research Forum cells have been started in the following colleges,

- Govt. Science College, Jorhat (Jorhat Institute of Technology) Contact: Mr. Prasanta Kumar Bordoloi, Senior Lecturer Mail: [email protected] Mobile: +91-9957036339 -Arya Vidyapeth College, Guwahati Contact: Mr. Pabitra Kalita, Senior Lecturer Mail: [email protected] Mobile No: +91-9613133859 & Dr. Pradip Bhattacharyya, Senior Lecturer Mail: [email protected] Mobile No: +91-9864087494

To run the forum smoothly, to make it more organised and to speed up activities, formation of a committee/team is essential. The combined discussion of the moderators and senior members make the forum feel the importance of Advisors, co-ordinator, volunteer, webmasters etc. Of course it needs more discussion and will be approved by poll. • Guidelines for the members are being

formulated by the moderators of the NE India Research Forum. These guidelines are placed in the forum for discussion.

8. Guidelines for the forum The moderators formulated some guidelines for the forum which are as



follow. These guidelines were kept open for discussion in the forum. With time and need the guidelines will be changed.

1. Anybody in the forum can start a meaningful and constructive discussion after discussion with moderators.

2. Comments from the individual members do not necessarily reflect the view of the forum.

3. No single moderator can take a crucial decision. All decision would be taken by the moderators unanimously or together with the group as majority.

4. One should not write any massage to the forum addressing some particular members. It should always start with Dear all / Dear esteemed members etc.

5. If one has to write a mail to a particular member she/he should write personal mail.

6. Everyone has the freedom to speak but that doesn’t mean that one should attack personally. Of course we do have differences. There can be debate or discussion, but it should always be a healthy one. One’s personal comment should be written in such a way that it reflects his/her view only. It should not touch other's sentiments/emotions.

7. Whenever we are in a forum, society, home, members should be sensitive / caring enough to their comments so that it does not hurt sentiment of any second members.

8. Members should not post greetings messages (Bihu wish, New Year wish etc) to the forum.

9. Members should post authentic news only. The source of the news should be authentic. No controversial news or comment should be posted to the forum.

10. Our main aim is to discuss science to generate science consciousness, scientific temperament, sensitivity, awareness and research for the benefit of the mankind in general and North East India in particular.

11. In severe cases, moderators can take a hard decision unanimously or majority wise (may be through poll). (This point needs to be accepted by all the members).

While sending request or while fulfilling request for articles please follow the following points.

• The forum has been formed to help each other. When a member requests articles/literature to forum, members of the forum are always happy to help the person by supplying the articles. But at this stage we have to keep in mind that the article should be sent to the person who requested it, not to the whole forum as it creates lots of unnecessary mails in the message box of the forum. Moreover if it continues, it becomes an irritation also for many members.

• It is also the duty of the person who requests article to acknowledge the person who helped him/her. This can be done by writing ' Request fulfilled by.........' in the subject area while composing the mail and write a thanking message in the main message board. Once this is done, then if some other members want to send the article will know about the status of the request. This will also help members in keeping mailbox clean. For example,



Sub: Thanks: Article received: Chem. Pharm. Bull 1985, 33, 4764-4768 Dear Friends,

I, hereby, would like to extend my sincere thanks to my friends, A and B for providing me with the above mentioned article. I also thank other group member friends for their kind co-operation. Thanks and Best regards X

• Before asking for article, he/she should always check his/her institute/university libraries (online resources). If it is not available or accessible then only the member should request to the forum.

• Moreover sending articles (copyright protected articles) to the open forum violates copyright act. So please send the article to the person who requests not to everybody through this open forum.

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I think that’s right, but let me check. source: www.math.hope.edu

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1. Prof. Birbal Sahni

Birbal Sahni, FRS (1891-1949) was an Indian paleobotanist who studied the fossils of the Indian subcontinent. He founded the Birbal Sahni Botanical Institute in Lucknow. Birbal Sahni was born on 14th November 1891 and got his early education in India at Lahore and graduated from Emmanuel College, Cambridge in 1914. He later studied under Professor A. C. Seward, and was awarded the D.Sc. degree of London University in 1919. He returned to India and served as Professor of Botany at Banaras Hindu University, Varanasi and Punjab University for about a year. In 1921, he was appointed as the first Professor and Head of the Botany Department of the Lucknow University. The University of Cambridge recognized his researches by the award of the degree of Sc. D. in 1929. During the following years he not only continued his investigations but collected around him a group of devoted students from all parts of the country and built up a reputation for the University which soon became the first Center for botanical and palaeobotanical investigations in India. He established the Institute of Palaeobotany under the aegis of The Palaeobotanical Society on 10th September, 1946. Professor Sahni was recognized by several academies and institutions in India and abroad for his research.

[Continued to page 12]



Transparent Aluminum Is ‘New State Of Matter’

ScienceDaily (July 27, 2009) — Oxford scientists have created a transparent form of aluminium by bombarding the metal with the world’s most powerful soft X-ray laser. ‘Transparent aluminium’ previously only existed in science fiction, featuring in the movie Star Trek IV, but the real material is an exotic new state of matter with implications for planetary science and nuclear fusion. In the journal Nature Physics an international team, led by Oxford University scientists, report that a short pulse from the FLASH laser ‘knocked out’ a core electron from every aluminium atom in a sample without disrupting the metal’s crystalline structure. This turned the aluminium nearly invisible to extreme ultraviolet radiation. ''What we have created is a completely new state of matter nobody has seen before,’ said Professor Justin Wark of Oxford University’s Department of Physics, one of the authors of the paper. ‘Transparent aluminium is just the start. The physical properties of the matter we are creating are relevant to the conditions inside large planets, and we also hope that by studying it we can gain a greater understanding of what is going on during the creation of 'miniature stars' created by high-power laser implosions, which may one day allow the power of nuclear fusion to be harnessed here on Earth.’ Molecule turns red at breaking poing Materials hosting the right chemical may offer a colorful signal of stress Feeling the stretch a polymer spiked with a color-changing molecule turns red seconds before it snaps. The

technology may one day allow damage to be easily spotted. Engineers one day may not have to guess when a bridge is about to break. New materials that flush red in response to damage may provide a visible warning sign of trouble to come, scientists report in the May 7, 2009 Nature.

“I think it could be a milestone,” says Christoph Weder, a polymer chemist at Case Western Reserve University in Cleveland and at the University of Fribourg in Switzerland, who wrote a commentary in the same issue of Nature. The materials’ chameleon-like abilities are thanks to a small four-ringed molecule called a mechanophore. When the weakest bond in the mechanophore breaks, the molecule creates a dog-bone shape, and the reaction causes the molecule to redden. “This is really a proof-of-concept paper,” according to them. “Before the material can be used as a mechanical force sensor, there are practical issues that need to be addressed,” including how light may interfere with the desired signal and how the color-change might be made permanent.

Yeast bread to bear artificial vanilla Researchers have co-opted fungi to produce the flavor more efficiently

Yeast has long been pressed into service for making food and drink, and now scientists have recruited the fungus for a loftier flavor: vanillin, vanilla’s dominant compound. Scientists report in an upcoming Applied and Environmental Microbiology that they have engineered strains of beer and baker’s yeast to produce vanillin from glucose, a greener and cheaper route than previous methods. Vanillin is the



dominant compound of the hundreds that are found in vanilla — an extract from the seed-bearing pods, called beans, of two orchids, Vanilla planifolia and Vanilla tahitensis. But real vanilla beans are precious, rare and costly. Today, less than a percent of the vanillin sold each year is derived from the orchids. The majority of vanillin is synthesized in chemistry labs, and typically made from lignin, a constituent of wood left over from the paper-making industry, or guaiacol, which is derived from wood creosote.

Now Hansen, Birger Lindberg Møller of the University of Copenhagen in Denmark and colleagues created a chemistry lab of their own within two different species of yeast: Schizosaccharomyces pombe, also known as fission or beer yeast, and baker’s or brewer's yeast, Saccharomyces cerevisiae.

To further increase the yeast yield of vanillin, the researchers then added an additional gene that encodes for a plant enzyme that converts the straight vanillin into a form with a sugar attached, vanillin beta-D-glucoside. This form isn’t toxic at all, says Møller, allowing the yeast to hold much more the compound. And because the added sugar is easily broken down in the mouth or on the skin, both the straight

and sugar-laden vanillin could be used in foods and perfumes. Vanillin may also find its way into pain-relieving drugs, Møller says. Vanillin is one of the molecules in the biochemical pathway that leads to capsaicin, the compound that gives chili peppers their heat and is under investigation as a pain reliever.

(http://www.sciencenews.org/view/generic/id/43124/title/Yeast_bred_to_bear_artificial_vanilla)

Advance In 'Nano-Agriculture:' Tiny Stuff Has Huge Effect On Plant Growth With potential adverse health and environmental effects often in the news about nanotechnology, scientists in Arkansas are reporting that carbon nanotubes (CNTs) could have beneficial effects in agriculture. Their study, scheduled for the October issue of ACS Nano, found that tomato seeds exposed to CNTs germinated faster and grew into larger, heavier seedlings than other seeds. That growth-enhancing effect could be a boon for biomass production for plant-based biofuels and other agricultural products, they suggest.

Tomato seeds exposed to carbon nanotubes

(right) sprouted and grew faster than unexposed seeds (left).

Mariya Khodakovskaya, Alexandru Biris, and colleagues note that considerable scientific research is underway to use nanoparticles -- wisps 1/50,000th the width of a human hair -- in agriculture. The goals of "nano-



agriculture" include improving the productivity of plants for food, fuel, and other uses. The scientists report the first evidence that CNTs penetrate the hard outer coating of seeds, and have beneficial effects. Nanotube-exposed seeds sprouted up to two times faster than control seeds and the seedlings weighed more than twice as much as the untreated plants. Those effects may occur because nanotubes penetrate the seed coat and boost water uptake, the researchers state. "This observed positive effect of CNTs on the seed germination could have significant economic importance for agriculture, horticulture, and the energy sector, such as for production of biofuels," they add. (www.ScienceDaily.com)

Hot Chili Peppers Help Unravel The Mechanism Of Pain Capsaicin, the active ingredient in spicy hot chili peppers such as the jalapeno, is most often experienced as an irritant, but it may also be used to reduce pain. A new work published by Drs. Feng Qin and Jing Yao in PLoS Biology uses capsaicin to uncover novel insight into how pain-receptor systems can adapt to painful stimuli.

Capsaicin acts by binding to a receptor in the cell wall of nerve endings and triggering an influx of calcium ions into the neuron. Eventually, the nervous system interprets this cascade of events as pain or heat, depending on which nerves are stimulated. Scientists had previously linked the pain-relieving effects of capsaicin to a lipid called PIP2, found in cell membranes. When capsaicin is applied to the skin it

induces a strong depletion of PIP2 in the cell membrane. "The receptor acts like a gate to the neurons," said Qin. "When stimulated it opens, letting outside calcium enter the cells until the receptor shuts down, a process called desensitization. The analgesic action of capsaicin is believed to involve this desensitization process. However, how the entry of calcium leads to the loss of sensitivity of the neurons was not clear." "What changed was the responsiveness threshold," said Qin. "In other words, the receptor had not desensitized per se, but its responsiveness range was shifted. This property, called adaptation, would allow the receptor to continuously respond to varying stimuli over a large capsaicin concentration range." The findings have implications for pain sensation mechanisms as well as clinical applications. With an adaptive response, the receptors are essentially autoregulated without a fixed threshold, thus the intensity of the pain you experience is dependent on the recent history of pain. (www.ScienceDaily.com)

Plastic That Grows On Trees

Some researchers hope to turn plants into a renewable, nonpolluting replacement for crude oil. To achieve this, scientists have to learn how to convert plant biomass into a building block for plastics and fuels cheaply and efficiently. In new research, chemists have successfully converted cellulose - the most common plant carbohydrate - directly into the building block called HMF in one step. The result builds upon earlier work by researchers at the Department of Energy's Pacific Northwest National Laboratory. In that work scientists produced HMF from simple sugars derived from cellulose. In this new



work, researchers developed a way to bypass the sugar-forming step and go straight from cellulose to HMF. This simple process generates a high yield of HMF and allows the use of raw cellulose as feed material.

PNNL researchers can now take cellulose to HMF in one step, a process that might someday replace crude oil to make fuel and plastics. (sciencedaily.com) "In biomass like wood, corn stover and switchgrass, cellulose is the most abundant polymer that researchers are trying to convert to biofuels and plastics," said chemist Z. Conrad Zhang, who led the work while at PNNL's Institute for Interfacial Catalysis. HMF, also known as 5-hydroxymethylfurfural, can be used as a building block for plastics and "biofuels" such as gasoline and diesel, essentially the same fuels processed from crude oil. In previous work, PNNL researchers used a chemical and a solvent known as an ionic liquid to convert the simple sugars into HMF. ScienceDaily (May 20, 2009)

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[Continued from page 8] Short biography- Birbal Sahni He was elected a Fellow of the Royal Society of London (FRS) in 1936, the highest British scientific honor, awarded for the first time to an Indian botanist. On 10th April 1949, Professor Sahni succumbed to a heart attack. His greatest contribution was the discovery of a new group of fossil gymnosperms which he called the

"Pentoxyleae". Sahni studied fossil leaves of Ptilophyllum, stem of Bucklandia and flower of Williamsonia and concluded that they all belong to the same plant which he reconstructed and named as Williamsonia sewardiana. He was elected Vice-President, Palaeobotany section, of 5th and 6th International Botanical Congress 1930 and 1935, respectively; General President of the Indian Science Congress for 1940; President, National Academy of Sciences, India, 1937-1939 and 1943-1944. In 1948 he was elected a foreign Honorary Member of the American Academy of Arts and Sciences. Another high honor came to him was his election as an Honorary President of the International Botanical Congress, Stockholm in 1950.’ 2. Meghnath Saha Meghnad Saha (October 6, 1893 – February 16, 1956) was an Indian astrophysicist best known for his development of the Saha equation, used to describe chemical and physical conditions in stars.

Meghnad Saha was born in a village near Dhaka (in present Bangladesh). Meghnad Saha belonged to a poor family and struggled to rise in life. He had his initial schooling at Dhaka Collegiate School, and later moved to Dhaka College. [Continued to page 27 ]



Pinakpani Chakrabarti Professor, Biochemistry

Bose Institute Kolkata, India

A graduate of Cotton College (first class first in chemistry honours, 1974), P. Chakrabarti did his MSc from the Indian Institute of Technology, Kharagpur, and received his PhD from the Indian Institute of Science, Bangalore in 1981. He did his post-doctoral work on structures of small organic molecules at ETH, Zurich, and then switched to protein crystallography while working at Purdue University, University of California at Los Angeles and California Institute of Technology, USA. In 1990 he joined the National Chemical Laboratory, Pune, and was in-charge of the X-Ray diffractometer facility. In 1977 he moved to Bose Insitute, Kolkata, where he is now a Senior Professor at the Biochemistry Department, and also Scientist-in-charge of the Bioinformatics Centre. Prof. Chakrabarti’s research interest spans structural biology, biophysics and bioinformatics and he has authored more than 100 papers. He has contributed to our understanding of the conformation and folding of protein molecules, and the physicochemical principles underlying macromolecular recognition and binding. His determination of the structure of CII explains why this transcription activator binds a direct repeat DNA sequence. A few transcription factors which are important for the virulence of Vibrio cholerae have been characterized by biophysical methods and their cognate DNA sequences determined. Prof. Chakrabarti has also studied the effect of nanoparticles, which are being

developed for drug delivery, on protein structures. Prof. Chakrabarti has been

elected to the Fellowships of all the three major Academies of Science in India. He is involved in a number of committees of DST, DBT, CSIR, UGC etc. He is married to Sarmistha and their two children, Averi and Aveek, are going to college. It was an honour for Prof. Chakrabarti when he was invited to deliver a talk in Cotton College in 2008. He has visited a number of institutes in the North-East. Last August he visited the North-East Institute of Science and Technology, Jorhat to deliver a talk at the Bioinformatics Infrastructure Facility that has been developed there.

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Science knows no country, because knowledge belongs to humanity, and is the torch which illuminates the world. Science is the highest

personification of the nation because that nation will remain the first which carries the

furthest the works of thought and intelligence.

-By Louis Pasteur

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Dr. Prodeep Phukan, reader at the Chemistry Department of Gauhati University is visiting University of Tuebingen, Germany starting 1st of July 2009 for three months. His area of research is catalysis. Mr. Bipul Sharma received young scientists award in Chemistry and Allied Sciences by Dr. K. V. Rao Scientific Society, Hyderabad, Andhra Pradesh. He was awarded as runner. Dr. Binoy Saikia has attended the International Conference on Neutron & X-ray Scattering (ICNX2009), Kualalumpur, Malaysia from 29th to 1st July 2009 to present a oral presentation on X-ray scattering technique. He was awarded the "International Union of Crystallography (IUCr) Young Scientist Award" in the conference. Mr. Gunin Saikia has visited Mainz Germany to attend the conference “Frontiers in Polymer Science 2009” from 7-9th June 2009. Mr. Saikia is pursuing research as a CSIR-SRF for his Ph.D. in the Department of Chemistry, Indian Institute of Technology Guwahati. His area of research, “Synthesis of π-conjugated oligomers/polymers for optoelectronic device applications”. Mr. Prasenjit Khanikar has joined as graduate research assistant at department of Mechanical and Aerospace Engineering North Carolina State University, in the Program of PhD in Mechanical Engineering. Mr. Khanikar did his BE from Jorhat Engineering College and MTech from IIT Delhi

Mr. Nilkamal Mahanta has joined in the PhD program at department of Chemistry, Texas A & M University, Collge Station Texas. Mr. Mahanta is the top rank holder in both BSc (Hindu College , Delhi University) and MSc (IIT Delhi). Mr. Ankur Bordoloi has joined in the PhD(Mechanical Engineering) program at Minnesota University. Mr. Bordoloi did his BE from REC Allahabad (now NIT Allahabad) and MTech from IIT Kanpur. Mr. Arindam Goswami has joined in the PhD program at Department of Chemistry, University of Texas, Arlington. Mr. Goswami did his BSc from Jorhat Science College and MSc from Delhi University.

Mr. Pankaj Barah has recently joined Department of Biology, Norwegian University of Science and Technology (NTNU) as a Research fellow and associate faculty in Computational Systems Biology. He has received fellowship from European Union and Norwegian Research Council. The main research theme is to understand complex host defense mechanism and develop holistic mathematical models using data available from various high throughput technologies like Metabolomics, Transcriptomics, Genomics, Proteomics. It will be kind of exclusive Computational Systems Biology project to model complex Biological systems using interdisciplinary techniques.

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Charge-Coupled Devices (CCD)

By Dr. Abdul Wahab A charge-coupled device (CCD) is a two-dimensional grid (array) of semiconductor capacitors that can transfer charge between each other. While the term is widely used for image sensors, it actually describes the process by which the charges are transferred through the capacitors towards the grid edge. That is, under the control of an external circuit, each capacitor can transfer its electric charge to one or another of its neighbors. CCDs can be used as computer memory, electronic filters or for delaying samples of analog signals. Today, they are most widely employed in arrays of photoelectric light sensors to serialize parallel analog signals. Indeed, they have transformed the way scientists measure and chart the universe. Specifically, CCDs are used in digital photography, digital photogrammetry, astronomy (particularly in photometry), sensors, electron microscopy, medical fluoroscopy, optical and UV spectroscopy, and high speed techniques such as lucky imaging. History In 1968 F. Sangster and K. Teer of the Philips Research Laboratories invented the Bucket-Brigade Device. This device basically transfers charge packets from one transistor to another. One year later, Willard Boyle and George E. Smith of the Bell Laboratories (now part of Murray Hill, New Jersey-based Lucent Technologies Inc.) extended this concept by inventing a charge transport mechanism from one capacitor to another and they termed “Charge

Bubble Device”. Initially designed as memory device, soon after the invention other applications were suggested. Since the CCD chip was sensitive to light it could be used as an image sensor. By 1969, Bell researchers were able to capture images with simple linear devices; thus the CCD was born. The first who recognized the potential of the CCD for high quality scientific images were astronomers. Because CCD had a significantly higher sensitivity than the devices of that time: photographic film and vidicon tubes. By 1975, CCDs were being used in TV cameras and flatbed scanners. Since 1974, the NASA Instrument and Sensing Technology program has been relying in the CCD technology. In the 1980s, CCDs appeared in the first digital cameras. Figure 1 shows an example of the use of the CCD detectors in mini spectrometers.

Figure 1: CCD detector used in a mini UV-Vis-NIR spectrometer

(Hamamatsu). Basics of Operation All CCDs work on the same principle. There is a photoactive region (an epitaxial layer of silicon) on the surface, and a transmission region made out of a shift register. When an image is projected through a lens onto the capacitor array (the photoactive region) causing each capacitor to accumulate an



electric charge proportional to the light intensity at that location. A one-dimensional array, used in line-scan cameras, captures a single slice of the image, while a two-dimensional array, used in video and still cameras, captures a two-dimensional picture corresponding to the scene projected onto the focal plane of the sensor. So, once the array has been exposed to the image, a control circuit causes each capacitor to transfer its contents to its neighbor (operating as a shift register). The last capacitor in the array dumps its charge into a charge amplifier, which converts the charge into a voltage. By repeating this process, the controlling circuit converts the entire semiconductor contents of the array to a sequence of voltages, which it samples, digitizes and stores in some form of memory. CCD Manufacturing The photoactive region of the CCD is, generally, an epitaxial layer of silicon. It has a doping of p+ (boron) and is grown upon the substrate material. In buried channel devices, the type of design utilized in most modern CCDs, certain areas of the surface of the silicon are ion implanted with phosphorus (or nitrogen), giving them an n-doped designation. This region defines the channel in which the photogenerated charge packets will travel. The gate oxide, i.e., the capacitor dielectric (array of electrode), is grown on top of the epitaxial layer and substrate. Later on in the process polysilicon gates are deposited by chemical vapor deposition, patterned with photolithography, and etched in such a way that the separately phased gates lie perpendicular to the channels. The channels are further defined by utilization of the LOCOS process to produce the channel stop region. Channel stops are thermally grown

oxides that serve to isolate the charge packets in one column from those in another. These channel stops are produced before the polysilicon gates as the LOCOS process utilizes a high temperature step that would destroy the gate material. The channels stops are parallel to, and exclusive of, the channel or charge carrying regions. Channel stops often have a p+ doped region underlying them, providing a further barrier to the electrons in the charge packets. Nickel is deposited to form ohmic contacts to the source and drain, and aluminum is deposited and patterned to form the interconnect metal. Here the charge packets may consist of electrons (e–) or holes (h+). A cross section of a buried channel SiC CCDs is shown in Figure 2. It is noteworthy that the clocking of the gates, alternately high and low, will forward and reverse bias to the diode and is provided by the buried channel (n-doped) and the epitaxial layer (p-doped). This will cause the CCD to deplete, near the p-n junction and will collect and move the charge packets beneath the gates – and within the channels – of the device. Again, CCD manufacturing and operation can be optimized for different uses. The above process describes a frame-transfer CCD. While CCDs may be manufactured on a heavily doped p++ wafer; it is also possible to manufacture a device inside p-wells that have been placed on an n-wafer. This second method, reportedly, reduces smear, dark current, and infrared and red response. This method of manufacture is used in the construction of interline devices. An 8-bit (32-stage) four-phase buried channel overlapping-gate SiC CCD shift register is shown in Figure 3.



Figure 2: Cross section of an overlapping-gate buried channel CCD. The n-type channel layer is formed by nitrogen ion implantation. Charge packets are confined to potential wells under the gate electrodes and are shifted to the right by the proper sequence of clocking signals applied to the gates.

Figure 3: The four-phase buried channel overlapping polysilicon gate CCD in 6H-SiC. The input circuit is on the right, and charge packets are shifted to the left under the influence of clocking waveforms. The output circuit, consisting of a floating output diffusion, a preset transistor, and an off-chip amplifier, are located at the left.

Architecture and Sensor Sizes The CCD image sensors are implemented in several different architectures. The most common are full-frame, frame-transfer and interline. The distinguishing characteristic of each of these architectures is their approach to the problem of shuttering. In a full-frame device, all of the image area is active and there is no electronic shutter. A mechanical shutter must be added to this type of sensor or the image will smear as the device is

clocked or read out. With a frame-transfer CCD, half of the silicon area is covered by an opaque mask (typically aluminium). The image can be quickly transferred from the image area to the opaque area or storage region with acceptable smear of a few percent. The image can then be read out slowly from the storage region while a new image is being integrating or exposing in the active area. Frame-transfer devices typically do not require a mechanical shutter and but it requires twice the silicon real estate of an equivalent full-frame device. The interline architecture extends the concept of opaque mask one step further and masks every other column of the image sensor for storage. In this device, only one pixel (pixel is the contraction of picture element) shift has to occur to transfer from image area to storage area; thus, shutter times can be less than a microsecond and smear is essentially eliminated. However, as the imaging area is now covered by opaque strips, dropping the fill factor to approximately 50% and the effective quantum efficiency by an equivalent amount. Modern designs have addressed this problem by adding microlenses on the surface of the device to direct light away from the opaque regions to the active area. Microlenses can bring the fill factor back up to 90% or more depending on pixel size and the overall system's optical design. One may get confused that CCDs cannot be used for color imaging, since they respond only to light intensity. So, digital color cameras generally use a Bayer mask over the CCD. Each square of four pixels has one filtered red, one blue, and two green (the human eye is more sensitive to green than either red or blue). The result of this is that luminance information is collected at every pixel, but the color resolution becomes lower than the luminance resolution. Of course, better color



separation can be achieved by three-CCDs and a dichroic beam splitter prism that splits the image into red, green and blue components. Each of the three CCDs is arranged to respond to a particular color. Some semi-professional digital video camcorders (and most professional camcorders) use this technique. A Bayer filter design is shown in Figure 4. Sensor sizes are often referred to with an imperial fraction designation such as 1/1.8" or 2/3", this measurement actually originates back in the 1950s from the time of vidicon tubes. Compact digital cameras and Digicams typically have much smaller sensors than a Digital SLR and are thus less sensitive to light and inherently more prone to noise. Figure 5 shows CCD area image sensors.

Figure 4: A Bayer filter on a CCD.

Figure 5: CCD area image sensors.

Drawbacks CCDs have been moving closer to becoming an ideal detector but not yet there. They do have some drawbacks like fading − although the coupling process is quite efficient, moving the charges along a row of many hundreds or thousands of pixels adds up to a

noticeable loss of charge; blooming − if too many photons strike a CCD element, it gets “filled up” and some of the charge leaks to adjacent pixels; smearing − if light strikes the sensor while a transfer is taking place, it can cause some data loss and leave streaks behind bright areas of the image. Expense is still a concern − CCDs require a different manufacturing process from other computer chips. Some arrays need to be cooled for lower noise and higher sensitivity. Operating temperature is an important issue.

Figure 6: A specially developed CCD used for ultraviolet imaging in a wire

bonded package.

By Abdul Wahab J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech republic, Prague

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“Animals, whom we have made our slaves, we do not like to consider our equal.”

“A man who dares to waste one hour of time

has not discovered the value of life.”

-By Charles Darwin

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Guest Article

The growth of Intranet: Generations of Intranet

Dr. L. Shashikumar Sharma

Reader, Department of Management, Mizoram University, Aizawl.

Today, the internet has become a part and parcel of our business environment. The internet is used to gather information, to keep in touch with one another, to social network with like-minded persons and so on. But has the development of internet trickle down to internet as a business tool from its initial phase. An intranet is a network that connects the computers and networks within an organization by using the hardware and software that is used on the internet. Typically, it uses the TCP/IP protocols, server, and browser software for the internet. With intranet, the basic services of internet become available to the employees and business partners of the organization. This allows the employees and business partners to communicate effectively and quickly. Today’s intranets although uses the same technology of HTTP, TCP/IP and HTML are much more complex than the earlier intranets. In order to understand what has gone through to become intelligent intranets, let us trace the development of the intranets by dividing the periods in terms of generations of Intranets. First Generation Intranets The first generation intranets ere simple to look at and one cannot enter any information. The contents of the webpages remain the same unless the administrator edits it at the server.

These webpage were developed with little technical knowledge or within small time. The webpage were more or less “static” as the information on the webpage are fixed and does not change in any way. The first generation intranets contain high level information on their homepages and usually have links which connects to another webpage where more detailed information is shown. Second Generation Intranets The second generation intranets also contain static pages but some limited activities may be carried out. These sites may contain certain documents or pdf files which may be forms which can be printed out, fill up the form and submit to the required department. Or another method may be that the stored document is linked to a word processor. Upon clicking on the link, the word processor opens the document; it is then edited and e-mailed to the officer. Second generation web pages require some knowledge of computer meaning reasonably one has to be a computer literate person. These webpage can be set up with Microsoft Front Page or Macromedia Dreamweaver. Third Generation Intranets The third generation intranet was a leap over the second generation. Instead of the static webpages, its information was structured from a database, e.g., in the first and second generation intranets, an area of the webpage contains information in fixed text or graphics but in the third generation intranet, it will load from a database. The third generation intranet is a giant leap because to change the content of



the webpage, one no longer has to change at source of the webpage but only to change the information on the database. Secondly, users can directly enter information on the database. Since the information on the page comes from a database, it can display the updated information drawn from various databases from different locations. The drawback in the third generation intranet is that it now requires high level programming skills and special databases. First level and second level uses Common gateway Interface(CGI) scripts while the third generation intranet have to use more efficient and easier to program, such as Microsoft Active Server(ASP) and PHP, a special program developed to link HTML pages with databases. Security concern was another issue as such intranets as the database and webpages have to talk to each other. As the user can enter data at the database, it now requires to identify the users. Third generation intranet can be used to register new users, update their personal information, give application online etc. The third generation intranets have been traditionally run by IT/ HR departments. They are focused on official handbooks, procedures, policy documents and a place to display shared documents and presentations. The role of intranets as a virtual platform to share information would remain the same but who manages them will change in the next phase. Fourth Generation Intranets The latest, the fourth generation intranets are being heralded as intelligent intranets. It recognize the user on the basis of their logging on details and then present the information on the webpage which is relevant to the particular person. People with managerial responsibility would therefore receive different additional

information and be offered more functionality than people with no managerial responsibility. These portals can increasingly used as a point of contact between an organization and an employee, its customers and partners. This is achieved through a single interface where the authorized person can access the information stored in the multitude of databases stored in different locations. These portals may look like a standard browser but it still uses the standard client-server technology designed in such a manner that the software requirement is minimal at the user’s computer. Thus, these systems sometimes are known as thin-client although thin-client is a generic term used to describe a generic hardware configuration where a server does all the data processing and a user’s computer merely displays the output. In the fourth generation intranets, portals are tools used by employees and managers to access multiple databases to do monitoring, resource management and collaboration. With such a portal, when the user logs in, the system recognizes who they are and their user rights, and gives connectivity and access to whatever database they need. Expectations from the fourth generation intranet The fourth generation intranets are expected to identify the information gaps. Earlier method of identifying information gaps was a labour intensive exercise. The failed searches in the intranet will provide what information was searched by the users and it can provide an insight as a data collection and reporting tool and thus provide constantly updated information to the users. The fourth generation intranets are able to use the techniques used by modern commercial websites with the ability to provide search lists to make informed suggestions as per the requirement of



the user. It will also expand the ownership of content from administrators to users in the organization without having to acquire special knowledge. Another outcome is the ability to conduct a paper trial. Users sometimes cannot identify when the document has been modified, accessed and reviewed. The fourth generation intranet would help to identify redundant information and keep a paper trial of the document. It should also able to provide popular searches and documents as in the popular search engines like yahoo and Google. This will give a knowledge of the current information requirement of the organization. E.g., if searches have been for words like ‘bully’, ‘abuse’, ‘teasing’ etc. then it provides a lot of information about the work environment. Fourth generation intranets should provide information in formats that uses rich media applications with flexibility. Videos,, discussion forums, interactive calendars are the new features which are forming as the mainparts of the fourth generation intranets. The intranet can be used for formal meetings to deliberate on company policies, video conferencing. It can also offer an are where people can share the same document, leave messages for each other, record, store work, even set blogs, polls. It can be a tool where a newcomer can integrate to see who their colleagues are, what position they hold and what expertise they bring to the organization. The fourth generation intranet can respond to the demands of its users, can recover time that is often lost by searching older networks for documents and other resources. It can bring efficiency by saving 5 minutes search time every day per employee. For an organisation of 100 or more that’s 1 person’s time better employed

elsewhere. The time gained not only equates to a direct saving on costs but also encourages improvements in productivity with time saved on administering internal procedures. References: 1. Watson, Wyatt, (2002). B2e/Her Survey Results 2002, Watson Wyatt http://www.watsonwyatt.com/research/resrender.asp?id=200086!&page-1 2. Howlett, D and Rodgers, K. (2002). Delivering Value Back to the Business available from Http://www.portalsforprofit.co.uk 3. Danson, Danson (2008). Fourth Generation Intranets: The dawn of dynamic new business tool, inspired by social networking, that employees will want to use daily available from http://www.interact-intranet.co.uk About the author Dr. L. Sashikumar Sharma completed his M.Com and Ph.D from Manipur University, Imphal. He also obtained his MBA from IGNOU, New Delhi. At the moment he is working as an Associate Professor in the Department of Management, Mizoram University since March 2008. He can be reached at [email protected]

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“Science without religion is lame, religion without science is blind”

“Logic will get you from A to B. Imagination

will take you everywhere.” -By Albert Einstein

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Increasing Zinc Bioavailabity in Food Stuffs of Manipur: A Serious Threat

for Health

Dr. Kshetrimayum Birla Singh

Preamble: Inspite of the impressive progress that has been made in the field of trace element nutrition in the past, the biological role and minimum requirement of trace elements are still hypothetical. Information about daily dietary intakes based on sound methodology is scanty in developing countries. During the past couple of years, public health authorities in different parts of the world have started to take an interest in defining desirable levels of nutrient intakes for their populations. Some of these efforts have been duplicated at the international level by bodies such as World Health Organization (WHO) and the Food and Agricultural Organization (FAO) (Parr et al., 1990). Actual intake levels and bioavailability are two key factors that are nutritionally very important. Barring the occupational exposer, the food chain remains the major pathway through which trace elements enters human body (Abdulla et al., 1993). Zinc (Zn) as Trace Mineral:

Zinc (Zn) is one of the micronutrients found in virtually every tissue in the body and is particularly important for the correct functioning of the immune system, growth and development, and the antioxidant system and for the activity of a large number of Zn dependent enzymes (approximately

300) both in plants and animals. The main way in which it is used in the body is as an essential component (known as a ‘cofactor’) for the functioning of a large number of enzymes, proteins which act as catalyst, enabling the body to carry out the chemical reactions essential for life. Due to wide range of functions, daily requirements of Zn is 8µg at 1 month of age decreasing to 5 µg at 4-12 months of age and subsequently it again increases to the order of 3-5mg in 1-10 years old children. Normal adults on an average require 5-15 mg and pregnant women 10-25 mg of Zn daily (National Research Council, 1989). Zn is present in a wide variety of foods as trace elements needed for good health but they could be toxic and health hazards when their concentration and consumption level exceeds limits of prescribed and safe exposer (Reilly, 1991).

Status of Zn in Food Stuffs of Manipur: The survey of the literature indicates that studies related to determination of mineral status in different food stuffs available in India are scarce, particularly in North-Eastern States of India. In State like Manipur, where the production of local food stuffs could not meet the demand for the existing population, many foodstuffs have to be procured from outside the state particularly Punjab, Haryana, Uttar Pradesh, Bihar etc. In order to establish the status of Zn and Cu concentration, a survey was carried out in different food stuffs procured from other states and those foodstuffs (meat food stuffs) grown in the area of Manipur around Imphal. The survey revealed that Zn level was more than daily recommended range of 12.8-20mg Zn/kg diet in all the foodstuffs (ranges from 31.6 Zn mg/kg in rajma to



124.5mg Zn /kg in potato) procured from outside the Manipur but copper level was normal (Table-I). Among the foodstuffs grown in local area, rice, cauliflower, cabbage, rice bean, potato, mustard, broad bean, tomato and all those popular meat food stuffs have Zn concentration more than recommended range but their copper concentration is within the prescribed limit (Table-II). This increase in bioavailability of Zn in the different food stuffs of Manipur (both local and procured items) may be due to the uses of excess Zn in Agriculture and Husbandry practices for the commercial exploitations. During the last two decades with Green Revolution in India, Zn as a micronutrient is being used indiscriminately in agricultural sector which results in elevation of its concentration in plant products. The exogenous treatment of growth hormone or its analogues couple with high concentration of Zn as zinc sulphate (ZnSO4) in commercial feeds is being exploited in rearing the livestock on large scale for higher yield of animal products. These practices resulted in higher transfer of Zn level to vegetable and animal foodstuffs. There are reports from other study that revealed that due to use of different inputs in the fields by farmers during the growth of vegetables, Zn levels have increased more than the levels of prescribed limit (Ram et al., 2005).

Food stuffs Zn (mg/kg)

Cu (mg/kg)

Triticum aestivum (wheat)

46.2 46.8

Oryza sativa (rice)

40.8 54.8

Phaseolus lunatus (rajma)

31.6 10.0

Pennisetum glaucum (pearl millet)

42.4 31.8

Malka masher (pulse)

39.4 13.6

Horse pea (pulse)

54.6 42.6

Vigna radiate (mung bean)

49.2 45.0

Cicer arietinum (chick pea)

90.4 31.8

Arachis arietinum (groundnut)

39.0 41.0

Raphanus sativus (radish)

110.5 40.8

Brassica rapa (turnip)

1200 40.2

Daucus carota (carrot)

115.2 40.6

Ipomoea batatas (potato)

124.5 38.3

Allium sativum (garlic)

114.0 48.5

Allium cipa (onion)

98.5 36.8

Solanum lycopersicum (tomato)

54.3 45.8

Table-I: Showing Zn and Cu Concentration in Vegetable Food stuffs Available in Manipur but

Procured from Outside the State:

The clinical signs of zinc toxicosis:

• vomiting • diarrhoea • red urine • icterus (yellow mucous

membranes) • liver failure • kidney failure • anaemia

(Collected from net)



Food stuffs Local

Name Zn

(mg/kg)

Cu (mg/kg)

Oryza sativa (local rice)

Phou,Cheng

40.8 54.8

Brassica oleracea botrytis (cauliflower)

Kobi thamc

het manbi

49.6 33.0

Brassica oleracea var. capitata (cabbage)

Kobi 36.2 25.8

Vicia faba (broad bean)

Hawai mubi

32.3 14.0

Vigna umbellata (rice bean)

Chak hawai

39.0 41.0

Brassica spp (mustard)

Hangam

21.6 35.0

Solanum lycopersicum (tomato)

Khamen

asinba

42.3 9.6

Ipomoea batatas (potato)

Alu 45.6 38.3

Fermented fish

Ngari 70 51.0

Fish Nga 69.5 45.8

Chicken Yensa 139.0 57.0

Beef Sansa 175 61

Egg Yerum 102.8 46.8

Pork Oksa 170.0 48.0

Table-II: Concentrations of Zn and Cu in Vegetable Food Stuffs (and

meat food stuffs) Grown in the area of Manipur around the Imphal.

Hazard Effects of Excess Zn in Diet:

The consumption or intake of excess Zn in diet for long period of time have harmful effect especially during the growth phase of consumers since excess Zn in diet increases the growth hormone level in the blood which enhances the growth rate, increases the number of fat cells in the body, promotes absorption of fat and elevates insulin activity. On withdrawal of growth hormone on approaching adulthood, the absorbed nutrients are directed to fat cells under the influence of elevated insulin activity where they are deposited as fat. As a consequence of this, the children grow faster and add some fat in their tissues which make them to appear healthy but impose serious health problems on attaining adulthood. The continuous input of excess nutrients in tissues particularly in fat cells caused by excess nutrients in tissues particularly in fat cells caused by zinc over a period of time contributes to obesity in adults. Obesity seems to poses a formidable challenge to the growing population as it is etiologically linked to insulin resistance, an accompanying insulin dependent diabetes mellitus, hypertension and coronary artery disease

Sandstead, in his study in 1995, discouraged the use of Zn supplements in free-living population because doses greater than the RDA is associated with copper deficiency inspite the fact that Zn is an essential micronutrients. The excess free zinc ions in diet inhabited the copper absorption as a consequence of the similar physiochemical properties of these two elements and copper-zinc antagonistic reaction at intestinal level



producing copper deficiency in them. The interaction between zinc and copper is of practical concern because, it can occur with relatively low amount of zinc supplementation. Copper deficiency is known to induce hypertension, increase blood cholesterol (hyper-cholesterolemia), and low-density lipoprotein (LDL) fraction increment in blood which add to the condition favouring heart attack both in young and old age population. Although data are not conclusive, there were reports of high prevalence of obesity and increasing incidences of obesity related diseases in the Manipur population. Recent data on obesity in the population of Manipur revealed that the prevalence of obesity is more than the national average and have increased from 10.9% to 13.4% in male and 10.6% to 17.1% in female residents of Manipur in the year 1999 to 2006 and is further increasing (NFHS, 2006). Mungreiphy and Sawanti in 2008, have also reported increase prevalence of overweight and obesity among Tangkhul Naga tribal women of Manipur during last many years. Many epidemiological studies reported that there had been a link with excessive dietary Zn and increase in prevalence of obesity and other diseases, as its increase in diet than the recommended dietary allowance (RDA) was evaluated to increase the body fat in rats, and higher Zn levels were observed in nail, hairs, and urine in obese than in normal subjects ((Sukumar and Subramanian 1985; Taneja et al., 1996; Taneja et al., 1998). According to Singh et al., 2001, there was an increase in prevalence of diabetes mellitus in the young age population of Manipur. This rise in prevalence of obesity and related diseases in Manipur population may possibly due to the higher intake of zinc through foods as a result of indiscriminate use of zinc in animal

husbandry and agricultural practices in the quest for better yields. It seems that dietary factors are more involved than any other factor in the prevalence of obesity and other related diseases in the Manipur population. The type of the food consumed by the Manipur population including staple food mainly consist of rice and vegetarians dishes made up of potato, mustard, cabbage, cauliflower, garlic, onion, pulses, cereal base dishes and fermented fish (Iromba, Kangsoi, Kangou, hawai thongba etc.). Nonvegetarian food was more common in both plain and hill areas with more consumption of chicken, pork, beef and fish, all being found to be rich in Zn contents investigated in the survey. In Manipuri society, the culture of arranging and organising grand feast during the festive seasons and other traditional rituals has been a common feature and this resulted an increased in frequency of consumption of these Zn rich food stuffs and which further aggravated the deteriorated nutrition system.

Conclusion:

The obesity, diabetes, hypertension and heart attacks though are genetic disorders but their dramatic rise and their onset at relatively young age population of Manipur during the last two decades is rather a recent phenomenon associated with agriculture boom achieved through excessive and extensive used of micronutrients in which Zn stands prominently. The abandoning of traditional copper containing metallic utensils, the compulsory sources of copper through its leaching into food during cooking has further aggravated the condition. Zinc management in food, therefore is essential to contain the obesity related diseases. This can be targeted by immediate and long-term strategies. The immediate strategy



involves the restricted consumption of Zn rich food items such as meat food stuffs and increased inclusion of zinc binding products such as fibre leafy vegetables and phytate rich legumes such as soyabean and its product that should reduces its bioavailability. This is particularly important for those who have genetic predisposition, i.e., family history of these disorders, irrespective of signs of clinical symptoms. The use of copper utensils for cooking will not only help in preventing the copper deficiency but also reduced the influx of zinc in them. The long term strategies required a stator controlled used of zinc in commercial feeds and agriculture practices through legislation in interest of human health, otherwise the obesity related diseases would dominate further in the days to come in Manipur population.

References: 1. Parr R.M., Abdulla, M., Aras, N.K.

et al., (1990). Dietary intakes of trace elements and related nutrients in eleven counties: preliminary results from an IAEA co-ordinated research program, Proceedings, 7th International symposium on trace elements in man and animals, TEMA-7 ed B. Momcilovic, 3,13. Zagreb: IMI.

2. Abdulla, M., Parr, R.M & Iyengar, G.V (1993). Trace element requirements, intake and recommendations. In Essential and toxic trace elements in human health and disease, ed. AS Prasad, 311-328. New York: Wiley-Liss.

3. National Research Council (1989). Recommended dietary allowances, 10th ed. (National Academy Press, Washington DC).

4. Reilly, C (1991). Metal contamination of food. 2nd ed. Elsevier Applied Science, London.

5. Ram, B., Garg, S.P., Matharu, S.P (2005). Effects of contaminants in waste water on soil and vegetables- a case study, Panjab Pollution Control Board.

6. Sandstead, H.H (1995). Requirements and toxicity of essential trace elements, illustrated by zinc and copper. Am.J. Clin Nutr., 61:621-625.

7. Third National Family Health Survey (2006). Mumbai: International Institute for Population Sciences.

8. Mungreiphy, N.K. and Sawanti, K (2008). Overweight, obesity and socio-economic change among Tangkhul Naga Tribal women, North East India. In Nature Proceeding.

9. Sukumar, A and Subramanium, R (1992). Elements in hair and nails of urban residents of New Delhi: CHD hypertension and diabetic cases, Biol Trace Elem Res., 34, 89-98.

10. Taneja, S.K., Mahajan, M and Arya, P (1996). Excess bioavailability of zinc may cause obesity in humans, Experientia, 52:31-33.

11. Taneja, S.K., Mahajan, M., Gupta, S and Singh, K.P (1998). Assessment of zinc and copper status of hair and urine of young women descendents of NIDDM parents, Bio Trace Elem Res., 62: 255-264.

12. Singh, T.P., Singh, A.D and Singh T.B (2001). Prevalence of diabetes mellitus in Manipur. In Shah, S.K. Editor. Diabetes Update, Guwahati. North Eastern Diabetes Society. 13-19.



Information about the author Dr.Kshetrimayum Birla Singh completed his M.Sc. Degree from the Department of Zoology (Centre for Advance Study), Panjab University Chandigarh in the year 2003. After selected as Junior Research Fellow (JRF) in CSIR-UGC Combined Examination held on December 2002, he then joined as Ph.D. scholar in the Department of Zoology, Punjab University Chandigarh in the year 2003 under the supervision of Prof.S.K. Taneja (Professor Emeritus) and got his Ph.D Degree in September 2008. Presently, he is working as Assistant Professor in the Department of Zoology, Pachhunga University College, Mizoram University, Aizawl since January, 2007. His field of specialization is in Animal Physiology and Biochemistry and area of research interest are trace elements, metabolic syndrome-X, molecular based antioxidant enzymes and nutrition. He is also Principal Investigator of the UGC- sponsored research project entitled ‘‘Study on the effect of long term excessive Zn supplementation on oxidative stress in wistar rats’ He can be reached at [email protected]

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[Continued from page 12 ] Short biography : Meghnath Saha He was also a student at the Presidency College, Kolkata; a professor at Allahabad University from 1923 to 1938, and thereafter a professor and Dean of the Faculty of Science at the University of Calcutta until his death in 1956. He became Fellow of the Royal Society in 1927. He was president of the 21st session of the Indian Science Congress in 1934. Meghnad Saha's best-known work concerned the thermal ionisation of elements, and it led him to formulate what is known as the Saha equation. This equation is one of the basic tools for interpretation of the spectra of stars in astrophysics. By studying the spectra of various stars, one can find their temperature and from that, using Saha's equation, determine the ionisation state of the various elements making up the star. Saha also helped to build several scientific institutions, such as the Physics Department in Allahabad University and the Institute of Nuclear Physics in Calcutta. He founded the journal Science and Culture and was the editor until his death. He was the leading spirit in organizing several scientific societies, such as the National Academy of Science (1930), the Indian Physical Society (1934), Indian Institute of Science (1935) and the Indian Association for the Cultivation of Science (1944). A lasting memorial to him is the Saha Institute of Nuclear Physics, founded in 1943 in Kolkata He also invented an instrument to measure the weight and pressure of solar rays.

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Muga silkworm, is it safe in near future?

Mahananda Chutia

[email protected] Central Muga Eri Research & Training

Institute (CMER&TI), Lahdoigarh, Jorhat-785700, Assam,

India

Muga culture is a part of the rich tradition of the people of North East India and is economically viable crop to the rural people. Muga silkworm (Antheraea assamensis Helfer) is a golden silk producing lepidopteron insect endemic to North Easter part of India, especially in Assam and hence, it can be termed as a treasure of Assam. Muga are not found in any part of this globe other than Brahmaputra Valley. The insect is semi-domesticated, polyphagous and multivoltine in nature having five to six generation in a year. The silkworms are raised on som and soalu plant (Machilus bombycina and Litsaea polyantha). The female moth lays about 120-200 eggs after mating for 6-8 hrs (Annual Report, 2001-02). The larvae are reared, outdoors on the above mentioned host plants in outdoor conditions. When the larvae are ready to spin the cocoons, they are collected by the rearers and allowed to spin the cocoons in a “jali', made up of dried plant twigs. From those cocoons, the golden yarn silk is found after necessary processing.

As we all know, four different types of silkworms are available in nature from which different types of silk yarn is produced commercially i.e. Mulberry, Eri, Tasar and Muga. Mulberry is the domesticated silkworm (indoor rearing) which occupy above 80% of the total silk production in the globe. However, muga culture is popular among the people and also a cultural tradition of Assam. It provides self employment to the rural people to

about two lakhs families where 65% of the workers are women and 52.4% from weaker section of the society (Benchamin, 2000). The area under the muga host plant in Assam is about six thousand hectares. Due to diverse topography, the natural forests of NE India offer a variety of habitats and ecosystems to its

inhabitants and hence the region is included among the 25 biodiversity hot spots declared in the world. Thus, congenial climatic condition of the area may become the natural abode for numbers of insect species. Wild

counterparts of muga silkworm are also available in different eco-pockets of

Wild

Mug

aM

ulbe

rry

Eri

Silkworms and Products



North East India. Those wild counterparts have been reported by the Scientist which were different in larval body coulour (yellow, blue and orange) and low survivability (Barah et al, 1990; Sengupta et al, 1975).

Being an exothermic insect, the

environmental factors such as temperature, humidity, rainfall etc and other biotic factors play an important role in every stage of growth and development of the muga larvae. Due to out door nature of rearing, young larvae expose to various rigours changing of environment during different rearing periods throughout the year which often threats to the larvae. The insect is very much sensitive to the environment and the pests and parasite can easily attack or infect the larvae in filed condition. The larval immune system is not so strong which can protect the insect from the infection of the pathogens. Again, the young stage larvae are the very good food of the wild birds. Some flies and bugs also harm the larvae in rearing periods in the field. As a whole, the insect is not at all safe day by day in their natural habitats and also in the rearing farms. Due to the rigorous

change of environment and raise in temperature, the insect are becoming unable to adopt itself. Due to shortage of habitats and food, the birds always

keep on eyes to those semi-domesticated insects like muga and once get opportunity, catch it. Besides

these, they are also facing threats from the diseases and pests. Again, now-a-days, non virulent microorganisms are becoming virulent causing disease to

86.66%

4.55%8.16%

0.62%

Muga Eri Tasar Mulberry

Muga Eri Tasar Mulberry0

2000

4000

6000

8000

10000

12000

14000

16000

Tota

l Pro

duct

ion

in M

T

Silk

30

40

50

60

70

80

90

100

110

120

Pro

duct

ion

in M

T

1951-52 2004-05

5.58%

94.42%Assam

Arunachal Pradesh, Mizoram, Meghalaya, Nagaland, West Bengal, Manipur

Production of muga silk

Source: Central Silk Board, Bangalore.



the newer host and the muga silkworms also. For examples, muscardine disease (caused by Beauveria bassiana, a fungus) was not found in muga in earlier days (Chaudhury, 1981). During last few years, muscardine diseases in muga silkworm have been gradually increasing year after year and leading to the crop loss to the tune of 70-90% in Jarua crop (December-January) which is the pre-seed crop of Jethua commercial (April-May) crop (Das et al, 2009). Pebrine (protozoan), flacherie (bacterial) and grasserie (viral) are also the common three diseases in muga which also cause serious affect in muga rearing. Again, those wild populations of muga, they are also not at all safe in their native places due to deforestation, change of environment and increasing temperature and also from birds and other natural enemies. Such wild muga population will disappear soon from this globe in near future, almost within few years.

The biodiversity of north east part of the country are gradually declining due to havoc deforestation and degradation, agriculture, encroachment, grazing, forest fires, illegal extraction of forest products, replacement of indigenous species with exotics, un-coordinated infrastructure development, lack of proper coordination, in-migration, irresponsibility and many more factors as noticed by the experts. These drawbacks should be overcome and minimize to negative effects for conservation and proper utilization of our resources.

Hence, extensive study in farms, wild habitats and also establishment of a germplasm bank is the prime need of muga silk industry in North East India. There is an immediate need to undertake the strategies for conservation of the muga silkworm biodiversity. Establishment of a germ plasm bank, extensive survey,

cataloging and preparation of a distribution map, collection of wild gene pool, in situ conservation of wild counterparts, isolation of pure lines and disease resistant strains, breeding, development of stress resistant strains through recombinant DNA technology or through modern biotechnological tools etc are the priority research areas for conservation and proper maintenance to the muga silkworm at present situation.

This is the time, we every one should think about it and to take care of it to save this innocent poor insect in our place. There is no other home in this world for this insect. Otherwise, we may loss our tradition, culture and the treasure as it is a unique property of Assam. If muga is not there, we will not be able get the muga mekhela that means, we will unable to see our most and beloved festival “Bohag Bihu/ Rongali Bihu”. Then, how we will introduce ourselves as Assamese? Our pride, history, tradition and introduction have been straightly associated with muga! Whether we will be able to see our traditional “husori” without wearing the muga mekhela and sadar? A “nachani” wearing other than muga mekhela chadar in a “husori”, can we will be able to bear it? Many people/scientists from the different country of the world came to know about Assam just for muga culture and muga silk. How we will feel proud if muga is not there in our tradition, in our culture?

Source: NE Quest, April 2007



Reference: 1. Annual Report (2001-02) Central

Muga Eri Research and Training Institute (CMER&TI), Lahdoigarh, Jorhat, Assam.

2. Barah A, Bhuyan N, Barah BR and Sengupta AK (1990) Collection, maintenance and introduction of suitable races of muga silkworm Antheraea assama: Survey and collection of wild muga silkworm. Annual Report, RMRS, Boko, 26-27.

3. Benchamin KV (2000) Economics of muga and eri sericulture in North east India. Proceedings of the seminar on sericulture R&D in Muga and Eri, CMER&TI, Lahdoigarh, Jorhat, Assam, pp. 236-242.

4. Choudhury SN (1981) Muga Silk Industry. Directorate of Sericulture, Govt. of Assam, Guwahati, Assam.

5. K Das, M Chutia, R Das and R Chakravorty (2009) Impact of bio-pesticides on indigenous golden silk producer muga silkworm, Antheraea assamensis Helfer (Lapidoptera: Saturniidae) in different crop seasons. Souvenir abstracts, International symposium on “Second Green Revolution: Priorities, Programmes, Social and Ethical Issues” held at Rajiv Gandhi Centre for Biotechnology, Thiruvanthapuram, Kerala, India on 2-4 July, 2009.

6. Sengupta K, Singh K and Das SK (1975) Studies on combining ability and expression of hybrid vigour in Antheraea assama Ww. Annual Report, CMERS, Titabor, 38-39.

About the author: Mahananda Chutia of Dhemaji district of Assam, passed his B.Sc. (1st rank & distn) from Dibrugarh University and M.Sc. from Gauhati University, Assam. Then, he joined as a Research Fellow in the Dept of Biotechnology, Gauhati University with Prof G.U. Ahmed research group in a Project. Later, he joined in MAEP Division, North East Institute of Science & Technology (formerly RRL, Jorhat) with Dr. T.C. Sarma research group. He worked as CSIR Senior Research Fellow (SRF) till January 2009. Presently, he is working as a Scientist-B in Microbiology, Pathology and Biotechnology Lab, Central Muga Eri Research & Training Institute (CMER&TI), Central Silk Board, Lahdoigarh, Jorhat (Assam). His area of research includes Silkworm Pathology, Molecular Biology and Microbial Biotechnology.

--------------0----------------

“The Roots of Violence: Wealth without work, Pleasure without conscience,

Knowledge without character, Commerce without morality, Science without humanity,

Worship without sacrifice, Politics without principles”

-By Mahatma Gandhi

--------------0----------------



On the shape of TL glow curve of bulk ZnS powder

L. Robindro Singh

Department of Physics, PUC, Mizoram University, Aizawl-796001, India

E-mail: [email protected] Introduction: Zinc sulphide phosphor containing Mn+2 is widely used in electroluminescent displays. There is extensive literature on ZnS:Mn phosphors at ambient pressure with emphasis on the electroluminescent properties and photoluminescent studies. Lang et. al. [1-9] reported the presence of two TL peaks at 133K and 236K in ZnS:Mn:Cu:Cl when recorded with ambient temperature. As the high pressure increases from 4kbar to 65 kbar they found new shallower traps. An interesting result was the shifting of peak temperature towards high temperature side with the increase of pressure. Chen et. al. [2] studied the absorption and luminescence in ZnS nanocrystals prepared by chemical route. Recent advances in the synthesis and characterization of nanosized semiconductors indicated that more exciting opportunities are lying ahead if the structure be scaled down to nanometer level. Mandal et. al. [3] reported the optical properties of nanocrystalline ZnS films prepared by high pressure magnetron sputtering. Chandra et. al. [4] studied spectroscopy of mechano, electro and photoluminescence of ZnS: Cu, Ce and ZnS:Ag,Ce phosphors. The present article reported preparation of ZnS phosphors at low temperature and thermoluminescence studies with different doses of irradiation. Experiments:

The preparation procedure is similar to the earlier reports of Singh et.

al. and S.C. Qu et al. [9,10]. Calculated amount of ZnCl2 (GR, Merck)is dissolved in 100 ml methanol (GR, Merck) and then stoichometric amount of Na2S (GR, Merck) dissolved in double distilled water is simply added to this solution. The reaction medium is room temperature and kept in nitrogen atmosphere in order to resist oxidation. Just after addition of aq.Na2S, thick cloudy white precipitate is obtained. The precipitate so obtained is filtered, after filtration the sample is kept in a decicator. The sample is annealed at 900 °C and used for further analysis.

The sample so prepared is annealed at 900 ° and irradiated with gamma rays from a Co60 source and thermoluminescence measurement is carried out using TL recording system TL 1404, supplied by Indotherm Instrument Pvt. Ltd., Mumbai. X-ray diffraction studies were carried out using a Philips powder X-ray diffractometer (model PW 1071) with Ni filtered Cu-kα radiation. The lattice parameters were calculated from the least square fitting of the diffraction peaks.

Results and Discussion: Theory: Thermoluminescence is the emission of light from a semiconductor or insulator when heated, which is initially exposed to radiation. Three steps are necessary for the production of light: firstly the material must be an insulator or a semiconductor – metals do not exhibit luminescent properties. Secondly, the material must have at some time absorbed energy during exposure to radiation. Thirdly, the luminescence emission is triggered by heating the material. The luminescence emission mechanism is shown in figure 1.

Fig. 1: Schematic diagram for the production of light-excitation and

emission.



Whenever a material is irradiated, electrons and holes are created. If electron-hole pairs recombine immediately and emit a photon that is known as fluorescence if the electrons and holes created do not recombine rapidly, but are trapped in some metastable states separately, they need energy to be released from the traps and recombine to give luminescence. If the detrapping process is caused by heating or thermostimulatuion, the luminescence called thermoluminescence. Thermoluminescence is a good way to detect the recombination emission caused by the detrapping carriers thermally. The energy corresponding to the glow peak is equal to the trap depth. What we must point out is that traps and carriers (electrons and holes) may be produced by irradiation, and they are also able to be created during sample processing.

When the recombination probability dominates the retrapping probability or retrapping probability is zero, Randall and Wilkins [11] have reported an expression for TL intensity of the first order kinetics (b=1) at a temperature T as:

])/(expexp[)/exp()(0

0 TdTkEskTEsnTIT

T

′′−−−= ∫β

where n0 is the initial concentration of trap electrons, s the frequency factor, E the activation energy, k the Boltzmann constant and β the linear heating rate. When the retrapping probability is the same as recombination probability then the expression for TL intensity of the second order kinetics is given by [12]

∫ ′′−′+−′=T

T

TdTkEsnkTEsnTI0

20

20 ])/exp()/(1/[)/exp()( β

where s=n0 s′ For the non-first order kinetics (b≠ 1) Gartia et.al. [13] and Rasheedy [14] reported an expression for TL intensity as

)1(1 ])/exp()1(1)[/exp()(0

−−− ′′−−+−= ∫ bbT

T

bb TdTkEsfbkTEsNfTIβ

where N is the electron traps and filling factor f=n0/N. The condition for maximum intensity for the glow curve obeying equation (3) is given by

∫ −=′′−−+ −−mT

Tm

bmb kTEfE

bskTTdTkEsfb

0

)/exp()/exp()()1(1 12

1

ββ

The shape factor μg, of the glow curve can also be determined from the relation [21] μg=δ/ω = (T2 – Tm)/ (T2 – T1 ) where Tm is the peak temperature of the glow curve and T1,T2 are the temperatures at half of the maximum intensity on the raising and falling sides of the glow curves.

Figure 2 shows the XRD pattern of ZnS, the diffraction peaks corresponds to the JCPDS 80-0020 and no other extra peaks could be detected, showing the prepared sample is pure.

Fig. 2: XRD pattern of ZnS phosphors prepared at 900 °C, the bracket gives indexing of different diffraction peaks.

The lattice parameters of the sample are a = 5.355 (1) Å with unit cell volume 153.560(1) Å. Fig. 3 shows the thermoluminescence (TL) glow curve of bulk ZnS irradiated with 126 Gy and 252Gy of gamma rays and recorded with a linear heating rate (β=1.73°C/s).

Fig. 3: Thermoluminescence (TL) glow curve of bulk ZnS irradiated with 126

Gy and 252Gy of gamma rays and recorded with a linear heating rate

(β=1.73°C/s).

10 20 30 40 50 60 70 80 90200

300

400

500

600

700

X-ra

y In

tens

ity (a

rb. u

nit)

2θ (degree)

(111)

(220)

(311)

(331)



The peak temperatures are 374 and 390K respectively. The full width at half the peak intensity are 94 and 83 ºC which is considerably large. It indicates that it must be a composite one although it looks like a single peak. Fig. 4 shows TL glow curves of ZnS irradiated with the similar doses in Fig. 1 but recorded after two days of irradiation and with a thermal cleaning up to 120ºC.

Fig. 4: TL glow curve of bulk ZnS recorded after thermal cleaning at 120ºC and

heating rate (β=1.6°C/s).

Now the full width ω of the peak has reduced. Again we have recorded TL peak of ZnS irradiated with 252Gy of gamma rays and with a linear heating rate β=1.6°C/s. Before measurement the sample has been thermally cleaned upto different temperatures like 100, 120, 140 and 170ºC.

Fig. 5a: Curve fitting of ZnS(β=1.6°C/s) phosphors irradiated with 126 Gy of gamma rays and recorded after thermal cleaning at120°C.

Fig. 5b: Curve fitting of ZnS(β=1.6°C/s) phosphors irradiated with 252 Gy of

gamma rays and recorded after thermal cleaning at 120°C

Fig. 5 shows curve fitting of ZnS phosphors irradiated with 252 Gy of gamma rays and recorded after thermal cleaning up to 120ºC. It could be fitted with two peaks at 376.1 and 406.4K. The thermal activation energies are 0.7 and 1.0eV with frequency factors 2X108 and 2.7x1011s-1. Both the peaks are non-first order kinetics (order of kinetics b=1.5). Singh [5] also reported that the order of kinetics for TL peak of ZnS nanocrystal recorded by Chen et. al. [2] is 1.5.

Acknowledgement: The author acknowledged Professor Sh. Dorendrajit Singh, Department of Physics Manipur University and Dr. R.S. Ningthoujam, Scientist E, BARC-Mumbai for their encouragement and constant help during the execution of this work. References: [1] Lang J M, Dreger Z A and Drickamer H G, J. Appl. Phys. 71 (1992) 1914 [2] Chen W, Wang Z, Lin Z, Lin L, J. Appl. Phys. 82 (1997) 3111 [3] Mandal S K, Chaudhuri S and Pal A K Thin Solid films 350 (1999) 209 [4] Chandra B P, Pandey R K, Chaturvedi G and Vaidya I 1997 NCLA, Raipur, 386 [5] Mahamuni S, Khosravi A A, Kundu M, Kshirsagar A, Badekar A, Avasare D B, Singh P and Kulkarni S K J. Appl. Phy 73 (1998) 5237



[6] Nanda K K, Sarangi S N, Mohanty S and Sahu S N Thin Solid Films 322 (1998) 21

[7] Bahera S N, Sahu S N and Nanda K K Ind. J. Phy 74A (2) (2000) 81

[8] Brus L Appl. Phy A 53 (1991) 465

[9] Singh W.S., Singh N.S., Soni A., Singh S.D., Singh L.R., Okram G.S., Ind. J.Phys. 81(12) (2007) 1267

[10] Qu S C, Zhou W H, Liu F Q, Chen N F, Wang Z G, Pan H Y and Yu D P Appl.Phys.Lett. 80 (2002) 3605

[11] Randall J.T. and Wilkins MHF A184 (1945) 366 [12] Garlick G.F.J. and Gibson A.F. Proc.Phy.Soc. 60 (1948) 574 [13] Gartia R.G., Singh S.D., Mazumdar P.S., Phys.Stat.Sol. 138 (1993) 319 [14] Rasheedy M.S., J.Phys: Condens.Matter 5 (1993) 633 Information about the author

Dr. L. Robindro Singh obtained his M.Sc and Ph.D from Manipur University, Imphal. At present he is working as Assistant Professor in the Department of Physics, Pachhunga University College, Mizoram University. He can be reached at : [email protected]

Reflection and Refraction of plane P -waves at a corrugated interface

between liquid – solid half-spaces -By Dr. S. S. Singh

1. Introduction The propagation of elastic waves and their reflection and refraction from the boundary surfaces are of great interest in the field of Applied Mathematics, Seismology, Geosciences and Engineering. The elastic wave propagation carries a lot of information about the medium through which they travel. Whenever these waves come across a discontinuity, the phenomenon of reflection and refraction take place. These studies give valuable information about the internal structure of the Earth. These reflected and refracted waves are not only influenced by the characteristics of the medium, but also by the shape of the interface (discontinuity) and frequency of the incident waves. The Seismic signals obtain through the interior of the Earth are very helpful in the exploration of valuable materials buried inside and also better knowledge about the constituents of the Earth. The problems of the propagation of elastic waves have been studied by many researchers and many are in open literatures, e.g., Achenbach [4], Aki and Richards [5], Ewing et al.[9], Lay and Wallace [13], Rayleigh [15], Sheriff and Geldart [17], Singh and Tomar [18], Udias [20], etc. When a plane elastic wave propagating through a medium becomes incident at a discontinuity boundary surface between two media, the reflection and refraction of elastic waves take place. Thus, the elastic wave propagation is affected by discontinuity, in general. These discontinuities present inside the Earth are not always plane interface and they cannot be approximated to a plane surface, all the time. In fact, these discontinuities are corrugated in nature and the undulated nature does affect the phenomena of elastic wave propagation. Therefore, while discussing the phenomena of elastic wave propagation, one must take account the roughness of the boundary surface. Lord



Rayleigh [14] was the first who studied the problems of reflection and refraction of waves from a corrugated boundary surface. In his book [Theory of Sound, 1896], he explained the reflection and refraction of light or sound waves from a corrugated boundary surface. In the Rayleigh's method, the function representing the corrugated interface containing in the boundary conditions are expanded in Fourier series and the unknown coefficients in the solutions are determined to any given order of approximation in terms of small parameter characteristics of the boundary surface. Later on, Rayleigh's method was applied to the problems of reflection and refraction of elastic waves. Many investigators have solved the problems of reflection and refraction of elastic waves using different techniques, i.e., Abubakar [1, 2, 3], Asano [6, 7, 8], Deresiewicz and Levy [10], Deresiewicz and Wolf [11], Dunkin and Eringen [12], Rice [16], Singh and Tomar [19], etc. In this problem, the problem of P – wave propagation through a corrugated surface between liquid – solid half spaces has been attempted by using the Rayleigh's method of approximation. The reflection and refraction coefficients corresponding to regular and irregular waves are obtained for the first order approximation of the corrugated interface. 2. Problem formulation and solutions Let us take x and y -axes be the two perpendicular Cartesian co-ordinates lying horizontally and z- axes be the vertical co-ordinate with the positive direction pointing downward. Suppose an isotropic elastic half-space, and a liquid half-space, be separated by a corrugated interface,

, where is a function of x independent of y, whose mean value is zero. The Fourier series expansion of is given by

n = 1, 2, 3, …… (1)

where and are the Fourier coefficients, p is the wave number and . Introducing constants, d,

and as

, n = 2, 3, 4, ...... (2) We obtain as

. If the corrugated interface is represented by only one cosine term, i.e., then the wavelength of the corrugation is and d is the amplitude of the corrugated interface. Suppose a P- wave propagating through the solid half-space, M becomes incident at the corrugated interface. This incident P -wave gives reflected P and SV -waves in the solid half-space, M and refraction P -waves in the liquid half-space, M’. The geometry of the problem is given in Figure 1.

Fig.1. Geometry of the problem.

The equation of motion of the elastic waves in terms of displacement potentials in the half-spaces, M and M’ are respectively given by Achenbach [4] as

(3) and ,

(4) where

and are the displacement potential of the

elastic waves in the half-spaces, M and M’ respectively, is the phase speed of P –wave, is the phase speed of SV-wave in the medium M with and as the elastic parameters in the medium and is the density; and is the phase speed of P -



wave and is the elastic parameter in the medium M’ with as the density. Let us consider two dimensional elastic wave propagation in x - z plane. The total displacement potential in the half-space, M (dropping the common factor, ) can be written as

(5)

(6) where is the amplitude and is the angle of incidence of the incident P-wave with as the wave number, A is the amplitude of the regularly reflected P -wave at an angle are the amplitudes of the irregularly reflected P -waves at angles , B is the amplitude of regularly reflected SV -wave at an angle with as the wave number and are the amplitudes of irregularly reflected SV -waves at angles . Similarly, the total displacement potentials of the refracted P -waves in the liquid half-space M’ (after dropping the common factor ) can be written as

(7) where D is the amplitude of the regularly refracted P -wave at an angle and are the amplitudes of the irregularly refracted P -waves at angles . The Snell's law which gives the relation between the angle of incidence with the angles of the reflected and refraction waves is given by (Asano, 1960) . (8) The Spectrum theorem which gives the relation between the angles of regular waves with the angles of the irregular waves is given by (Abubakar, 1962)

(9) In the Equation (9), (+ve) signs in the angles , and of the left hand side correspond to the (+ve) signs of the right hand side, while (-ve) signs in the angles , and of the left hand side correspond to the (-ve) signs of the right hand side.

2. Boundary conditions The boundary conditions are the continuities of displacement and stresses at the corrugated interface, . Mathematically, these boundary conditions can be written as At , (10)

(11)

, (12) where is the derivative of with respect to x and can be written as

. (13) Equations (10) - (12) give the boundary conditions for the plane P -wave propagation at the corrugated interface between the elastic solid and liquid half-spaces.

3. Solution of the first order approximation In the Rayleigh's method of approximation, the amplitude and slope



corresponding to the corrugated interface are assumed to be very small so that

etc. (14) Now, putting Equations (1), (8), (9), (13) and (14) into (10)-(12); and comparing the coefficients of the independent terms of x and on both sides of the equations, we obtain (15) (16)

(17) Next, comparing the coefficients of on both sides of the resulting equations, one can obtain the following equations as

(18)

(19)

(20) where

Similarly, comparing the coefficients of

the following equations are obtained

(21)

(22)

(23) where

Equations (15)-(17) give the ratios of the amplitude constants corresponding to the regularly reflected and refracted P and SV -waves. The solutions corresponding to the amplitude ratios of irregular waves for the first order approximation of the corrugated interface are given by Equations (18)-(23). Solving Equations (21)-(23), the amplitude ratios corresponding to regular waves are given by

(24) where



,

Thus, Equation (24) gives the reflection coefficient of the reflected P-wave and refraction coefficients of the refracted P- and SV-waves corresponding to the regular waves. This result is similar with those of plane interface Similarly, solving the Equations (18)-(23), the amplitude ratios corresponding to irregular waves are obtained as

(25) where

Thus, the reflection and refraction coefficients corresponding to the irregularly reflected and refracted waves are given in Equation (25) for the first order approximation of the corrugation. These coefficients are functions of the amplitude of corrugation, frequency of the incident wave, elastic parameters of the medium, reflection coefficients and refraction coefficient corresponding to the regular waves.

2.Particular case

If the amplitude of the corrugation is neglected, i.e., d=0, then the reflection and refraction coefficients corresponding to the irregular waves are equal to zero and there exists only the reflection and refraction coefficients corresponding to regular waves which are given by Equation (24). These coefficients given in Equation (24) are equivalent with those reflection and refraction coefficients corresponding to the plane interface.

(a)Again, if the lower half-space is replaced by another liquid, then there exist only reflected and refracted P-waves. In this case,

and the reflection and refraction coefficients are given by



,

. (35) This result is exactly matched with Ewing et al. [9] for the relevant problem.

(b) IIf the upper half-space is removed, then the problem reduces to the reflection of P and SV –waves at the free half space. In this case, the reflection coefficients are given by

,

.

(36) It is clearly seen that the reflection coefficients are functions of the angle of incidence of the incident P –wave and elastic parameters of the medium.

3.

Conclusion The phenomena of reflection and refraction of P – wave from a corrugated boundary surface between liquid – solid half spaces has been explained by using Rayleigh method of approximation. The reflection and refraction coefficients corresponding to the regular waves and irregular waves are obtained in closed form for the first order of approximation. These coefficients corresponding to irregular waves are derived for special type of periodic interface given by . It is obtained that

(i) AAll the reflection and refraction coefficients corresponding to regular and irregular waves are functions of angle of incidence, elastic parameters of the elastic solid and lamb parameter of the liquid,

(ii) AAll the reflection and refraction coefficients corresponding to regular wave are independent of corrugation and frequency parameters,

(iii)All the coefficients corresponding to irregular waves depend on the corrugation and frequency parameters.

(iv)The results corresponding to the plane interface are obtained from our analysis.

Acknowledgment The author acknowledges University Grant Commission, North Eastern Regional Office, Guwahati, India for their financial help in order to complete this work through the Grant No. F. 5-249/2008-09(MRP/NERO)/8139.

References [1] I. Abubakar, Scattering of plane elastic waves at rough surfaces I, Proc. Camb. Phil. Soc., 58, 136-157(1962). [2] I. Abubakar, Buried compressional line source in a half-space with an irregular boundary, J. Phys. Earth, 10, 21-38(1962). [3] I. Abubakar, Scattering of plane elastic waves at rough surfaces II, Proc. Camb. Phil. Soc., 59, 231-248(1963). [4] J. D. Achenbach, Wave Propagation in Elastic Solids. North-Holland Publishing Company, Amsterdam, New York, Oxford, 1976. [5] K. Aki and P. G. Richards, Quantitative Seismology. University Science Book, New York, 2002. [6] S. Asano, Reflection and refraction of elastic waves at a corrugated boundary surface, Part-I. The case of incidence of SH-wave. Bull. Earthq. Res. Inst., 38(2), 177-197(1960). [7] S. Asano, Reflection and refraction of elastic waves at a corrugated boundary surface. Part-II," Bull. Earthq. Res. Inst., 39(3), 367-466(1961). [8] S. Asano, Reflection and refraction of elastic waves at a corrugated interface, Bull. Seismol. Soc. Am., 56(1), 201-221(1966). [9] W. M. Ewing, W. S. Jardetzky and F. Press, Elastic waves in layer media. McGraw-Hill Book Company, New York, 1957. [10] H. Deresiewicz and A. Levy, The effect of boundaries on wave propagation in a liquid- filled porous solid: X. Transmission through a stratified medium, Bull. Seismol. Soc. Am., 57(3), 381-391(1967). [11] H. Deresiewicz and B. Wolf, The effect of boundaries on wave propagation in a liquid filled porous solid: IX: Reflection of plane waves at an irregular boundary, Bull. Seismol.



Soc. Am., 54(5A), 1537-1561(1964). [12] J. W. Dunkin and A. C. Eringen, Reflection of elastic waves from the wavy boundary of half-space, Proc. 4th U. S. Nat. Cong. Appl. Mech. (Berkeley), 143-160(1962). [13] T. Lay and T. C. Wallace, Modern Global Seismology, International Geophysics Series, Academic Press, NewYork, 1995. [14] L. Rayleigh, On the reflection of sound or light wave from a corrugated surface, Rep. Brit. Assoc. Adv. Sci., 690-691(1893). [15] L. Rayleigh, The Theory of Sound. Dover Publication, 1896. [16] O. Rice, Reflection of electromagnetic waves from slightly rough surfaces, Comm. Pure Appl. Math., 4, 351-378(1951). [17] R. E. Sheriff and P. L. Geldart, Exploration Seismology, Cambridge University Press, Cambridge, 1995. [18] S. S. Singh and S. K. Tomar, Quasi P-waves at a corrugated interface between two dissimilar monoclinic elastic half-spaces, Int. J. Solids Structs., 44(1) 197-228(2007). [19] S. S. Singh and S. K. Tomar, Elastic waves at a corrugated interface between two dissimilar fibre-reinforced elastic half-spaces, Int. J. Num. Anal. Meth. Geomech., 31(9), 1085-1116(2007). [20] A. Udias, Principles of Seismology, Cambridge University Press, Cambridge, 1999. About the author Dr. S. Sarat Singh has obtained his B.Sc. degree (2001) from Government College 11, Chandigarh. Then, he joined Department of Mathematics, Center for Advanced Study, Panjab University, Chandigarh for higher degrees and completed his M.Sc. Degree in Mathematics (2003) and Doctor of Philosophy (Ph.D., 2008). Presently, he is working as Assistant Professor, Department of Mathematics, Pachhunga University College, Mizoram University, Aizawl, INDIA. His research interest consist of Continuum Mechanics; Elastic wave propagation, Differential equations, Complex Variables and Numerical Methods. One can see his work on http://saratcha.googlepages.com/home

Saccharin

Saccharin is an artificial sweetener. The basic substance, benzoic sulfinide, has effectively no food energy and is much sweeter than sucrose, but has an unpleasant bitter or metallic aftertaste, especially at high concentrations. In countries where saccharin is allowed as a food additive, it is used to sweeten products such as drinks, candies, medicines, and toothpaste. Saccharin was first produced in 1878 by Constantin Fahlberg, a chemist working on coal tar derivatives in Ira Remsen's laboratory at the Johns Hopkins University. It was Fahlberg who, accidentally, discovered its intensely sweet nature. Fahlberg and Remsen published articles on benzoic sulfinide in 1879 and 1880. In 1884, now working on his own in New York City, Fahlberg applied for patents in several countries describing methods of producing this substance that he named saccharin. Fahlberg would soon grow wealthy, while Remsen merely grew irate, believing that he deserved credit for substances produced in his laboratory. On the matter, Remsen commented, "Fahlberg is a scoundrel. It nauseates me to hear my name mentioned in the same breath with him."

Although saccharin was commercialized not long after its discovery, it was not until sugar shortages during World War I that its use became widespread. Its popularity further increased during the 1960s and 1970s among dieters, since saccharin is a calorie-free sweetener. In the United States saccharin is often found in restaurants in pink packets; the most popular brand is "Sweet' N Low". A small number of soft drinks are sweetened with saccharin, the most popular being the Coca-Cola Company's cola drink Tab, introduced in 1963 as a diet cola soft drink.



Lindau meeting

The Nobel Laureate Meetings at Lindau is a scientific conference held yearly in Lindau, Germany, inviting Nobel Prize winners to present to and interact with young researchers from all over the world. In 1951, the two physicians Gustav Parade and Franz Karl Hein from Lindau convinced Count Lennart Bernadotte of Wisborg to assume patronage of the scientific meeting they set up to facilitate exchange with Nobel laureates in the field of medicine. Over the years the meetings grew, and laureates from chemistry and physics were also invited. The aim of the Lindau Meetings is to let young researchers interact closely with their supposed role models. Therefore the meetings do not only consist of presentations given by the laureates, but also of panel discussions, discussions in small groups and even joint dinners and lunches. The participating young researchers claim that the informal atmosphere and the intensive peer-to-peer contact provides a unique experience, while the organizers consider it crucial to both aims, scientific exchange and inspiration of junior scientists. This year the meeting was held in the area of Chemistry. Mr. Saitanya Kr. Bharadwaj, Mr. Sonit Kr. Gogoi and Mr. Subrata Das from IIT Guwahati attended the conference. Here Mr. Bharadwaj is sharing his experiences with the Nobel Laureates.

Linadu: The Nobel Island

By Saitanya Kumar Bharadwaj,

IIT,Guwahati From the day of our journey I was very much excited to meet Nobel Laureates. It was early morning of 27th June, when we had started from Indira Gandhi International Airport, Delhi. We landed at Munich and reached the dreamed Island, the “Island of Nobel Laureates” by 7.30 PM. The view of world-renowned postcard motifs at the harbor of Lindau namely Lighthouse and the Lion are really beautiful. On 28th June the unique meeting was started with the Inaugural Lecture of Countess Bettina Bernadotte, President of the council, which addressed the main theme of the meeting. The aim of the 59th meeting was to exchange of views and ideas between 23 Nobel Laureates and 580 young researchers from 67 countries towards finding solutions to the global challenges, particularly in the area of climate change and sustainability. German Federal Minister of Education and Research, Human Resource and Development Minister of India, and the Science and Research minister of China also took part in the opening ceremonies. Honourable Minister Kapil Sibal delivered a well-addressed lecture, which attracted the crowd gathered there. India, a copartner country for this year for this event, hence sponsored all activities of a single day. We had a cultural show where, one of our colleague performed Bharat Natyam and which magnetized the whole crowd.

All lectures by the Nobel Laureates were very much fascinating, enjoyable and encouraging. Out of all, Ertle’s (Gerhard Ertle, Noble prize 2007) lecture on heterogeneous catalysis inspired me a lot. Kroto’s (Harold W.



Kroto, Noble prize 1996) lecture on “Science Society and Sustainability” was really a great inspiration for me. His expression and presentation style was extraordinary and he’s actively participating in Science Education and popularization of science. The lectures by Martin Chalfie and Roger Tsien ((Noble prize 2008) Green Fluorescent Proteins (GFP) were really very very attractive. Particularly, the suggestions by Prof. Tsien to young researchers, was really great. He advised to find project, which puts neuroses in constructive use, gives sensual pleasure. He also recommended to make collaboration and asked to make Lemonade from Lemon. Informal discussion was a great opportunity to ask any doubt in our research or personal problem. They always gave positive suggestions. The positive attitude brought them to this position. They don’t consider any time limit for their work, they enjoy their work. Unless and until one doesn’t have own interest in his/her subject, he/she will not achieve successes, this is the view of almost all Nobel Laureates. I had the great opportunity to have dinner with Prof. Martin Chalfie. We were requesting him to share his feeling after the announcement of Nobel Prize. “Of course, I was quite happy to receive the honorable Prize, also I am lucky”- he smiled. Generally, a phone-call from Stockholm at around 4 AM brings the great news for the winner. Unfortunately Prof. Chalfie missed the phone-call as there was no phone in their bed room. He waked up at 6 AM and browsed Google and surprised to see his name in news (I was astonished to listen this because I read news in the newspaper about my nomination for Nobel Prize!). Chalfie was quite upset about Douglas Prasher and his wife Tulle Hazelrigg, because they also contributed in the root level of Green Fluorescent Proteins.

Chalfie said of Prasher's contribution: "Douglas Prasher's work was critical and essential for the work we did in our lab. They could've easily given the prize to Douglas and the other two and left me out”. Overall, it was wonderful trip for my life. Meeting Nobel Laureates, listening and talking with them, clearing doubts from them were fabulous experiences. They are the God of Science. The conference was concluded on 3rd July with a panel discussion entitled “Global warming and sustainability” on the Mainau Island, the heaven of the Earth. It is really rare to have such a great moment of attending meeting on one of the most beautiful Island in the world. An exhibition namely, “Discoveries” was also opened on that day where the scientific experiments, simulation related to water were focused. India was presenting the production of energy by splitting of water and treatment of wastewater plant, which attracted the visitors to the great extent. Fortunately I was accommodated with a young researcher from USA, I had a great experience by sharing our knowledges. I found that our educational system has vast difference from them. He was expert on one field whereas I had little knowledge on various areas, of course not expertise in any single field. There was also some interactive session where we shared our research experiences with other colleague from different countries. After the Lindau meeting we have visited various well known research laboratory and Universities like FHI of Chemical Physics and Inorganic Chemistry, Technical University of Berlin, University of Mainz, Bielefeld University, University of Bonn etc. We had various experiences during this visit. First, faculties or scientists introduced us to their research area with



a scientific presentation followed by laboratory visit which generally does not happen in our institutes. Secondly, the laboratories are highly equipped with all modern technologies. At last, I encourage all the Scientist, Faculty, Research scholar, and student from North Easter region to apply for the meeting and participate actively in near future. It is a great opportunity to explore ourselves internationally. Finally I thank all the member of North-east Indian Research Group, for sharing their experiences through the forum, leading me to this end and all of my well wishers. Also I thank Dr. Khiud Gogoi, for his help from the University life till today. I am grateful to Dr. Ashim Jyoti Thakur, TEZU, for his greatest help for this bon-voyage. Saitanya Kumar Bharadwaj is hailing from the village Hazarikapara, district of Darrang, Assam. He started his education from Salmass Utha Prathamik Bidyalay, then attended Gandhi Smriti Higher Secondary School, Sipajhar Higher Seconday and Multi Purpose School. He completed B.Sc. from Mangaldai College and awarded with M.Sc. from Department of Chemistry, Gauhati University in 2004. Subsequently in July 2005, he cleared the CSIR-JRF and GATE and joined the laboratory of Professor M. K. Chaudhuri at Indian Institute of Technology Guwahati for his doctoral studies. Prior to joining IITG, he was involving in a CSIR-sponsored project at NEIST Jorhat (formerly RRL Jorhat) from July 2004 to July 2005. He has published six papers in reputed international journals and co-inventor of one Indian Patent. Recently he has submitted the doctoral thesis (June 2009). He attended several national and international conferences including CRSI 2007 in Delhi University, PAN-IIT Global conference at California,

59th meeting of Nobel Laureates and students 2009 at Lindau Germany. He also delivered scientific presentation at Techniche’ 2007 and 2008 (The technical festival of IIT Guwahati). Mr. Bharadwaj can be reached at [email protected] Representative publications

1. Bharadwaj, S.K., Sharma, S.N., Hussain, S., Chaudhuri, M.K., Tetrahedron Letters 50 (27), pp. 3767-3771, 2009

2. Bharadwaj, S.K., Hussain, S., Kar, M., Chaudhuri, M.K. Applied Catalysis A: General 343 (1-2), pp. 62-67, 2008

3. Bharadwaj, S.K., Hussain, S., Kar, M., Chaudhuri, M.K., Catalysis Communications 9 (5), pp. 919-923, 2008

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Human brain is too efficient

Can you read the following

sentences ? Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are witren, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.



By Anupom Sabhapandit

The title of the thesis “Synthesis and evaluation of acrylamide polymers for enhancing petroleum recovery from high temperature subterranean deposits” Abstract Polymer flooding is considered as the cheapest chemical method of enhanced oil recovery. But the widely used polymers such as partially hydrolysed polyacrylamide and polysaccharides are not suitable for high temperature reservoirs having a temperature >800C. The necessity of high temperature, brine and shear resistant polymer is increasing with the increasing demand of petroleum as fuel. Synthesis and evaluation of some high temperature stable polymers is the principal aim of this work. A number of acrylamide-based copolymers are prepared, characterized and evaluated as Enhanced Oil Recovery (EOR) chemical for reservoirs having harsh conditions of salinity and temperature. They include, 1. Poly (acrylamide-co-Na-acrylate) [AM-NaAA], 2. Poly (acrylamide-co-Na-2-acrylamido-2-methylpropanesulphonate) [AM-NaAMPS], 3. Poly (N,N-dimethylacrylamide-co-Na-acrylate) [NNDAM-NaAA], 4. Poly(N,N-dimethylacrylamide-co-Na-2-acrylamido-2-methylpropanesulphonate) [NNDAM-NaAMPS],

5.Poly (acrylamide-co-N-vinylpyrrolidone) [AM-NVP] and 6.Poly (acrylamide-co-Na-vinyl -sulphonate) [AM-VSASS]. The copolymers are prepared by aqueous solution polymerization using either persulphate-metabisulphite redox pair or AIBN as initiator. They are characterized by their intrinsic viscosities, molecular weight (for an encouraging sample), compositions, thermal behaviour, brine compatibility, physical state and the functional groups present. IR, NMR (1H and 13C) and wide-angle XRD spectroscopy, TGA , DTA, DTG, and GPC etc. are used for characterization. Dilute solution rheological behaviour as well as thermal stability of these polymers are studied and evaluated for their use as EOR polymer. The effect of brine, effect of polymer concentration, effect of temperature and effect of shear on dilute solution viscosity of the polymers are studied. All the polymers obey Power Law Model through a wide range of shear and exhibit thixotropic behaviour. An ionic copolymer cannot regain its solution viscosity when allowed to shear at a constant rate for long period of time. But it can regain its solution viscosity when allowed to stay in presence of brine under a constant shear for a long period . Solvent effect on the rheology of NNDAM-NaAMPS copolymer, taken as a model polyelectrolyte is studied using four different solvents, Ethylene glycol(EG), Dimethyl


N. E. Quest; Volume 3, Issue 1, April 2009. 46

sulphoxide(DMSO), Ethyl alcohol (EtOH) and water (W). The reduced viscosity of the copolymer is highly dependent on the ionic strength of the copolymer solution. The reduced viscosity decreases as a function of solvent selection in the order W>DMSO>EtOH>EG. The shapes of the ηsp / C vs. C plots indicate the polyelectrolyte behaviour of the copolymer, except for the case of EG solutions, where non-polyelectrolyte like behaviour is observed. However, at a certain degree of ionization attained by adding W as cosolvent, the copolymer begins to demonstrate polyelectrolyte behaviour. The reduced viscosities of copolymer solutions increase with increasing temperature in W and DMSO, yet decreases with increasing temperature in EG. Two copolymers, namely, NNDAM-NaAMPS and AM-NVP show satisfactory thermal stability (at 1200C) at least for one month. There is no effect of brine on solution viscosity of AM-NVP as it is a non-ionic polymer. Viscosity reduction due to the presence of brine is comparable for all the copolymers except AM-NaAA. AM-NaAA suffers excessive viscosity reduction, especially in presence of bivalent cations. Though both NNDAM-NaAMPS and AM-NVP show good thermal stability, the viscosity build up of AM-NVP is very low. The adsorption behaviour of poly (N,N-dimethylacrylamide-co-Na 2-acrylamido-2-methylpropanesulphonate) is studied. Adsorption isotherms show that adsorption on bentonite is very high followed by that on limestone which, in turn, is much higher than that on sand surface following the order,

bentonite>>limestone>sand. On the addition of NaCl, adsorption on sand surface decreases to a minimum value and then increases. Adsorption increases with decreasing pH and also decreasing the content of NaAMPS in the copolymer. The amount of the copolymer adsorbed on sand surface is comparable to that of partially hydrolysed polyacrylamide but much less than that of poly (acrylamide-co-N-vinylpyrrolidone). The type of adsorption is found to be physical which is supported by the enthalpy of adsorption as well as by IR spectra. Efficacy of the copolymer NNDAM-NaAMPS as EOR chemical is studied. Core flood test using unconsolidated sand with mean diameter 228.14 μm having porosity 42% is carried out at different brine concentrations and temperatures. Initially crude oil fraction (150-3000C) and finally the crude itself is used as oil. After water-flood about 5.6% original oil in place (OOIP) can be recovered by injecting 2000 ppm polymer solution to the sand pack containing oil fraction and 5000 ppm NaCl brine. It is further confirmed that residual oil recovery increased with the increase of temperature. About 11% OOIP can be recovered as additional oil by injecting 2000 ppm polymer solution to the unconsolidated sand pack containing one of the Indian crude oil and brine consisting mono and bivalent metal ions at 900C. The recovery efficiency of NNDAM-NaAMPS and that of widely used AM-NaAA is found comparable under identical experimental conditions. Change in sand permeability and effect of sand size on recovery are also discussed.



The cross-linking behaviour of the polymers is studied in various conditions of salinity, polymer and cross-linker concentrations and temperature. Different cross-linking agents, especially Cr(III)-acetate are used for the study. Cr(III)-acetate is found more suitable for cross-linking in harsh conditions of temperature and salinity in a wider range of pH than the others. Among the polymers, AM-NaAA, NNDAM- NaAPMS and AM-NVP are found suitable for gel formation within the experimental conditions of this study. NNDAM-NaAMPS formed gel which is stable at 1200C at least for 2 months in presence of brine. Effect of polymer, cross-linker and brine concentration , effect of pH and effect of temperature on gelation are studied. The gelation time can be controlled by an adjustment of the polymer and cross-linker concentration and the pH. Rate of gelations in few cases are also studied by monitoring the viscosity increase with time. In conclusion, the advantages and drawbacks of each of the copolymers studied are presented. Finally it is concluded that the efficacy of NNDAM-NaAMPS as EOR polymer at high temperature is the highest among the polymers studied. At normal temperature, its efficacy is comparable to that of the others. In presence of bivalent brine, efficacy of AM-NaAA is poor even at low temperature. Dilute solutions of the rest of the copolymers are compatible with both monovalent and bivalent brine in a wide range of temperature and brine concentration. Though AM-NVP show stability against high temperature and brine, it is not encouraging from the

viscosity and adsorption point of view. Therefore, NNDAM-NaAMPS is the ideal polymer for high temperature reservoir.

Short bio-data of the author

Anupom Sabhapondit completed his M.Sc. in physical chemistry from Gauhati University in 1998. He did his Ph.D. from the Petroleum and Natural Gas division of Regional Research Laboratory , Jorhat and submitted the thesis to Dibrugarh University in August, 2002. From January, 2003 to December, 2006 he worked with the R&D division of Dai-Ichi Karkaria Ltd, Pune in the field of water soluble polymers including their applications. Presently he is working with the Production Enhancement department in Halliburton Technology Center, Pune. Main activities include development and application research in the field of oil well stimulation.

----------------0-------------- “To understand everything is to forgive

everything”

“You will not be punished for your anger, you will be punished by your anger.”

- By Gautam Buddha

----------------0--------------



Title of Thesis: Carbon-Carbon Bond Formation Reactions Using Solid Porous Catalysts By Dr. Pranjal Kalita Research Guide: Dr. Rajiv Kumar Place of research: Catalysis Division, National Chemical Laboratory, Pune, India The thesis is divided into SIX chapters, as summarized below: Chapter 1 presents a general introduction to various aspects of porous materials such as zeolites, mesoporous aluminosilicates and their physicochemical properties. Different structures of porous materials are shown in below. Salient features of certain metal oxides catalysts are discussed. Various instrumentation technique adopted for characterization of these catalysts are also described in brief. A detailed description is also given to various carbon-carbon bond formation reactions pertaining to the present study. The objectives of the present thesis research have also been highlighted. Chapter 2 presents the synthesis of Ce-containing mesoporous Al-MCM-41, synthesis of Zr-TMS catalyst and organofunctionalized by trifluoromethanesulphonic acid (triflic acid, TFA) on Zr-TMS catalyst, synthesis of Si-MCM-41 and SBA-15 materials and then immobilization of 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) on Si-MCM-41 and SBA-15 materials. The different techniques have been used for characterization of synthesized materials such as XRD, N2 adsorption, UV-visible, TPD-NH3, FT-IR, XPS, 13C, 29Si, and 27Al CP MAS NMR, SEM, TEM, AAS analysis and microanalysis. The different acid sites of Ce-Al-MCM-41 were identified by FTIR spectroscopy by adsorption of

pyridine and shown Figure1 and 2, respectively.

1700 1600 1500 1400

Ce-Al-MCM-41(38,34)Ce-Al-MCM-41(59,33)

Al-MCM-41(30)

Ce-Al-MCM-41(80,32)

Ce-MCM-41(30)

Frequency (cm-1)

Abs

orba

nce

(a.u

.)

(1.60)

(1.1)

(1.28)

(1.33)

(1.45)

(0.27)

(0.37)

(0.39)

(0.41)1636

16211613

1595

1545

14901452

1444

Figure 1. IR spectra of Ce-Al-MCM-41

samples, recorded at 300 K after exposure to saturation coverage of pyridine at 420

K followed by cooling to room temperature and subsequent evacuation.

Chapter 3 deals the catalytic activity of Ce-MCM-41, Al-MCM-41 and Ce-Al-MCM-41 catalysts. In this chapter various parameters have been studied, such as reaction time with different MCM-41 samples, different temperatures and solvents, recycle study and different substrates. Following are the main topics discussed. (a) Friedel-Crafts benzylation reaction under solvent free condition over Ce-MCM-41, Al-MCM-41 and Ce-Al-MCM-41 catalysts. (b) Preparation of 1, 5-dicarbonyl compounds by Mukaiyama-Michael reaction over Ce-MCM-41, Al-MCM-41 and Ce-Al-MCM-41 catalysts. (c) Preparation of β-hydroxy carbonyl compounds by Mukaiyama-aldol condensation under solvent free condition over Ce-MCM-41, Al-MCM-41 and Ce-Al-MCM-41 catalysts.



Figure 2. IR spectra of Ce-Al- MCM-41 samples, recorded at 420 K after

exposure to saturation coverage of pyridine at 420 K followed by evacuation for 10 min at

same temperature. Chapter 4 presents the catalytic activity of Zr-TMS and Zr-TMS-TFA catalyst. In this chapter various parameters have been studied, such as reaction time with different Zr-TMS-TFA samples, different amount of catalyst, temperatures, recycle study and different substrates. This chapter is divided into two parts- (a) Michael-addition of indoles to α, β-unsaturated carbonyl compounds over triflic acid loaded Zr-TMS catalyst. (b) Synthesis of coumarin and its derivatives over triflic acid loaded Zr-TMS catalyst by Pechmann reaction. Chapter 5 describes the catalytic properties of MCM-41 / SBA-15-TBD (1, 5, 7-triazabicyclo [4.4.0] dec-5-ene) mesoporous materials for the Michael-addition of β-nitrostyrene to malonate. In this chapter also various parameters have been studied, such as reaction time with MCM-41 / SBA-15-TBD samples, different amount of catalyst, temperatures, recycle study and different substrates.

Chapter 6 summarizes and concludes the results obtained and the basic findings of the present work. About the author

Dr. Pranjal Kalita was born (23rd March 1975) and brought up in Mangaldai, Assam. He received his B.Sc. (1996) from Mangaldai College, Gauhati University, Guwahati and M.Sc. (2000) from Assam University, Silchar, Assam (India) in Chemistry (M.Sc. project dissertation entitle Synthesis and characterization of tilted phase in liquid crystal). Then he joined the research group of Prof. Dibakar Chandra Deka at department of Chemistry, Gauhati University, as a project fellow and gained the research experience (2000-2002) in the area of Synthetic Organic Chemistry. In 2002, he qualified the CSIR junior research fellowship examination and moved to National Chemical Laboratory (NCL) to continue his doctoral studies. In February 2008, he completed Ph.D. degree under the guidance of Dr. Rajiv Kumar in the area of catalytic organic transformations. At present Dr. Kalita is working as a postdoctoral research scientist at National Institute for Material Science, Tsukuba, Japan. His research interest is on Synthesis and characterization of novel heterogeneous catalysts and its catalytic investigation to industrially and pharmaceutically important reactions. Apart from research activities he is an excellent singer of Assamese bihu songs. Dr. Kalita can be reached at [email protected] or [email protected]

1700 1600 1500 1400

Ce-Al-MCM-41(59,33)

Al-MCM-41(30)

Ce-MCM-41(30)

1452

14441613

1490

15451636

1621

1595A

bsor

banc

e (a

.u.)

Frequency (cm-1)



1. Mr. Gunin Saikia

Mr. Gunin Saikia is hailing from Majuli, Jorhat, Assam the biggest habitat river island in the world (present status: second biggest). He received his B.Sc. (2000) from Govt. Science College, Jorhat, Dibrugarh University and M.Sc. (2003) from Dibrugarh University, Assam (India) in Inorganic Chemistry. He was in Tezpur University, Tezpur as a project staff in 2004 for six months and joined as Junior Research Fellow in Defence Research Laboratory, Tezpur in October 2004. Presently Mr. Saikia is pursuing research as a CSIR-SRF for his Ph.D. in the Department of Chemistry, Indian Institute of Technology Guwahati under the supervision of Dr. P. K. Iyer. His area of research, “Synthesis of π-conjugated oligomers/polymers for optoelectronic device applications”. Recently Mr. Saikia has visited Mainz Germany to attend the conference “Frontiers in Polymer Science 2009”.

2. Arup Baishya

Mr. Arup Kumar Baishya, Born and brought up in village Jagara, Nalbari, did his BSc (Honours) in Biotechnology, Chemistry and Botany from St. Anthony’s College, NEHU, Shillong 1st class 4th with distinction.

He attended Iowa Western Community College, Iowa for summer school from June to August 2006. He then joined Rutgers, The State University of New Jersey and received his BS with summa cum laude (highest academic honours) in Biotechnology in 2008. At present he is doing MSc (Industrial Management) in Royal Institute of Technology (KTH), Stockholm, Sweden. He received several awards which include Full Scholarship from European Commission (current), Fulbright-PLUS (Partnership for Learning Undergraduate Studies) scholarship, 2006-2008, from the US Department of State, Certificate of Excellence in Academics and Community Service, 2006-2008, Academy for Educational Development, Washington DC, USA, Hilda S Foster Scholarship, 2007-2008, SEBS, Rutgers University, New Jersey, USA, Dean’s List, Spring, 08, Fall 2007, Spring 2007 and Fall 2006, Cook College, Rutgers University, New Brunswick, New Jersey, USA, President’s Honor Roll, 2006, Iowa Western Community College, Iowa, USA and NIUS (National Initiative on Undergraduate Science) fellowship from HBCSE, Tata Institute of Fundamental Research, Mumbai, India etc.

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Mr. Saitanya Bharadwaj, IIT, Guwahati. I must thank all the forum members for your support to our Forum, I especially thank all of them who has initiated this forum. I am proud to be a member of this forum. Being a member of this forum, I had received a mail (forgot the name of the sender) regarding the famous Lindau meet. Accordingly I had applied and Lucky enough to be one out of 43 student from India. We three (me, Subrata and Sonit) were representing the North-East. I would like to share some of my experience with you. It was a wonderful trip to Germany. Meeting Nobel Laureates, talking to them, formal and informal discussion with them were fabulous experience in my life. Every word of them was found to be important(I feel)for a research scholar. According to them "Enjoyment towards the work", "no time boundary for work", "always positiveness" are some factor for their success. They always consider quality of work rather than quantity. Apart from that we had visited several universities and research laboratories in Germany. That was also a very nice experience. Mr. Sushanta Kar, lecturer, Tinsukia College, Tinsukia, Assam

It was really an amazing experience to have an online journal like yours. Especially because you are working in a troubled and distant corner of the country. I went through your editorial. It was really motivating one. I hope the style and commitment, you have, will made us imagine, if we’re not

imagining yet, that one of us will be counted among the next Indian science Nobel Laureate. Though I try to a man of scientific temperament, I’m not a student of Science. I took special interest to your journal only because I too edit one such journal PRAGYAN from Tinsukia College. As you know that, not a single college of the region has such an environment that it effort to publish one complete research oriented journal like yours. So, we tried to be a little Student oriented. We publish everything which will benefit student folk along with the teachers. We have been publishing it since 2003. From the last year embark on net. You will find it here: http://sites.google.com/site/pragyan06now.

Like the latest issue of NE QUEST we too tried to cover up the International Year of Astronomy in our last June, 09 issue. Though, except two write ups on Total Solar Eclipse we failed to get any better articles like you. Anyway, I hope we can work together. I’ll surely make a news and if possible a review of your journal in our forth coming issue which will come up in the month of October next.

I wish you will keep your efforts up!

Dr. Ashim J. Thakur, Tezpur University, Tezpur, Assam

Personally, I feel, the standard of ‘N.E. Quest’ is improving gradually. It has grabbed my heart and soul in such a way that I use to check frequently when the next issue will come out just like the days when I was waiting for the ‘TINKLE’ every month. Although the enthusiasm of young writers is less,



yet the news letter has been coming out. I am particularly pointing to the female members whose contribution is not encouraging. The Volume 3 issue 1 came out nicely. Thanks to Dr. Debananda Ningthoujam. The invited article on climate change, ‘Global warming: disastrous effects and possible solutions’ by A. K. Puri and T. Satyanarayana is very informative and need of the hour. In my opinion, carbon emissions and our comfort are interrelated. Unless required, one man driving a four seater car, doesn’t it look add?

Mr. Prashant Divekar, Jnana Prabodhini, Pune, Maharastra

Since last few years I am reading the Northeast Quest.I feel very proud after reading the contributions done by scholars from Northeast in different branches of science.

I work with Jnana Prabodhini an Educational Institute which works with motto "Motivating Intelligence for Social Change".‘‘Motivating Intelligence’, according to Jnana Prabodhini, is an universal theme cutting economic, social, religious, or ideological differences. As long as the urge to change the society is there, other details prove to be of less significance. In fact, Jnana Prabodhini realizes that changing our society is a Herculean task and what is perhaps needed is a ‘meeting of minds’, thinking minds who want to change

things for better. Jnana Prabodhini in Marathi means Awakener of Knowledge. Jnana Prabodhini is resolved to bridge such minds through its work in the fields of Education, Research, Organization, Development, and Health.

Jnana Prabodhini has long association with Northeast. Our resource persons are associated with different educational and rural development activities in Northeast.We are associated with many student organisation from Northeast based at Pune.We run a forum Northeast Students Society a platform to help the student in his studenthood at Pune.

In last few years I had conducted Science camps for teachers and students in Assam, Arunachal Pradesh, Nagaland.Our focus is on Learn Science through Project method where student conduct a short action research on a problem for 6-8 days. In this camp we also work on skill development like observation skill, questioning skill, problem solving etc. which are important in science research.

I congratulate the publisher for publishing such knowledge aweakener and all the writers from northeast for their knowledge quest for the service of motherland.

(http://jnanaprabodhini.org/)

Do you know ?

• The temperature at the centre of the Earth is estimated to be 5500 degrees Celsius. • The thermometer was invented in 1607 by Galileo. • Englishman Roger Bacon invented the magnifying glass in 1250. • The Earth spins at 1,000 mph but it travels through space at an incredible 67,000

mph. • The deepest part of any ocean in the world is the Mariana trench in the Pacific with

a depth of 35,797 feet



Academic Chemistry and Biochemistry Departments in the United States http://www.library.ucsb.edu/subjects/chem/chemuniv.html Academic Chemistry and Biochemistry Departments Outside the United States http://www.library.ucsb.edu/subjects/chem/chemuni2.html Bioorganic Chemistry Links http://www.chem.arizona.edu/faculty/ghos/group.dir/links.html Top 25 Universities in the World (Courtesy: Forbes Magazine November 2009) No. 1 Harvard University No. 2 Stanford University No. 3 University of California, Barkley No. 4 Cambridge University No. 5 Massachusetts Institute of Technology (MIT) No. 6 California Institute of Technology (Caltech) No. 7 Columbia University No. 8 Princeton University No. 9 University of Chicago No. 10 Oxford University No. 11 Yale University No. 12 Cornell University No. 13 University of California, Los Angeles No. 14 University of California, San Diego No. 15 University of Pennsylvania No. 16 University of Washington No. 17 University of Wisconsin, Madison No. 18 University of California, San Francisco No. 19 The Johns Hopkins University No. 20 University of Tokyo No. 21 University College London No. 22 University of Michigan, Ann Arbor No. 23 ETH Zürich (Swiss Federal Institute of Technology Zürich No. 24 Kyoto University No. 25 University of Illinois, Urbana-Champaign

Top 10 Biomedical/ Bioengineering research universities in USA Source: US News & World Report

1. Johns Hopkins University, 2. Duke University

3. Georgia Institute of Technology, 4. University of California, San Diego

5. Massachusetts Institute of Technology, 6. Case Western Reserve University

7. University of Michigan, Ann Arbor, 8. University of Pennsylvania

9. Boston University, 10. Rice University



First International Conference on Conservation, Marketing and Patenting of Medicinal Plants (ICCMP)

18 to 20 December 2009, Raipur, Chhattisgarh, India

Website: http://herbfest2009.org; Contact name: Dr. R. N. Pati To address a wide range of serious issues relating to implementation of Global Strategy for Plant Conservation, promoting arrangements for registration of patent rights and linking livelihood opportunities with conservation Organized by: Council for Tribal and Rural Development, IK Foundation of India, VRM Foundation ; Deadline for abstracts/proposals: 30 August 2009

International Ph.D. Program, Zurich, Switzerland

The Life Science Zurich Graduate School houses several Ph.D. programs that cover distinct areas of the life sciences. Each program offers research and education opportunities in a stimulating international environment for ambitious students who wish to work towards a Ph.D. degree. Accepted students perform their research project in one of the participating research groups of their favorite program, according to their scientific interest. Advanced teaching and training courses are offered throughout the curriculum. The program language is English throughout. Ph.D. studies usually last 3-4 years. Applicants must hold or anticipate receiving a Master’s degree or equivalent from a university in a relevant field before starting the Ph.D. program. Applicants accepted for the program will have to register with either the University of Zurich or ETH Zurich, depending on the affiliation of their future research group.

Application deadlines: December 1st and July 1st

For details please visit : http://www.lifescience-graduateschool.ch/index.php?id=108

International PhD-Program in Austria 2010

International PhD-Program ‘Cell Communication in Health and Disease’ – CCHD 2010

Starting March 2010 & Application deadline: November 30, 2009

At the Medical University of Vienna, CCHD, a PhD Program in biomolecular Medicine supported by the Austrian Science Fund (FWF), has been established. The program offers cutting-edge education in the fields of Neurobiology, Vascular Biology, Immunology, and Inflammation Research and integrates basic, applied, and clinical sciences, as well as a huge spectrum of experimental techniques. Admitted PhD students will receive funding for at least three years including support to visit international onferences and specialized workshops. Applicants must hold a final degree in the diploma studies of Medicine, Dentistry, or in ny scientific/technical subject-related diploma studies (such as Cell or Molecular Biology) by the commencing term of the program.

Further information on research topics and courses, as well as application forms are available at: www.phd-cchd.at



ANNUAL BIOTECHNOLOGY CONFERENCE FOR STUDENTS (ABCS)

13th and 14th November (For students pursuing BSc, BE, BTech, MSc, ME, MTech in General Sciences, Health Sciences, Agriculture and Technology) @ International Institute of Information Technology (I2IT), Pune,

Maharastra, India

Conference Highlights

• Interactive sessions by leading experts in Biotechnology from industry and academia on: Stem Cells, Pharmaceutical / Vaccines, siRNA Technology, Microarrays / Proteomics

• Poster Presentation • Biotechnology Model Presentation • Student Innovation Award

Visit the link to register online http://www.isquareit.ac.in/Online_Registrations/Current_Events/registration_form_bio



For details visit http://www.tezu.ernet.in/academic/new_admission.html



Collage by Mr Saitanya Bhradwaj on his Lindau visit



Details about the Northeast India Research Forum

Date of creation of the forum : 13th November 2004

Area: Science and Technology Total number of members till date: 302

Moderators 1. Arindam Adhikari, Ph.D. Institute of Surface Chemistry, Stockholm, Sweden Email: [email protected]

2. Ashim J. Thakur, Ph.D. Chemical Science Dept, Tezpur University, Tezpur, Assam Email: [email protected]

3. Utpal Borah, Ph.D. Dibrugarh University, Assam, India Email: [email protected]

4. Khirud Gogoi, Ph.D. University of California, San Diego, La Jolla, USA; Email:[email protected]

Editorial Team of N.E. Quest

1. Debananda Ningthoujam, Ph.D. HOD, Biochemistry Dept. Manipur University, Imphal, India

2. Tankeswar Nath, Ph.D. Jubilant Organosys Ltd. Gajraula, UP, India Email: [email protected]

3. Manab Sharma, Ph.D. Australia, Email: [email protected] 5. Dr. Robert Singh Thangjam Dept. of Biotechnology, Mizoram University (Editor of this issue)

4. Shanta Laishram, Ph. D. Dept of Pure Mathematics, University of Waterloo, Canada Email: [email protected]

6. Pranjal Saikia Chemical & Materials Engineering Department;University of Cincinnati, Ohio, USA Email: [email protected]

7. Pankaj Bharali, Research Institute for Ubiquitous Energy Devices; National Institute of Advanced Industrial Science and Technology, Japan Email: [email protected]

8. Sasanka Deka, Ph.D. National Nanotechnology Laboratory, Lecce, Italy Email: [email protected] Cover Page designed by : Panacea Studio, Pune Logo designed by : Manab Sharma

9. Áshim Thakur, Ph.D. 10. Utpal Borah, Ph.D. 11. Arindam Adhikari, Ph.D 12. Khirud Gogoi, PhD

http://tech.groups.yahoo.com/group/northeast_india_research/ http://www.neindiaresearch.org/



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N.E.quest Vol 3 Issue 2 July 2009

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