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Cementation of Dust

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Cementation of Dust. Young Hun Yoon Peter Brimblecombe. University of East Anglia School of Environmental Sciences, Norwich, NR4 7TJ, UK. IMPACT OF VISITOR NUMBERS on DUST DEPOSIT. PREVIOUS WORK. HCP. OPH. AEH. 2. PROBLEM. ACCUMULATION. CEMENTATION. - Physical behaviour. - PowerPoint PPT Presentation
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Cementation of Dust Cementation of Dust Young Hun Yoon Peter Brimblecombe University of East Anglia School of Environmental Sciences, Norwich,
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Page 1: Cementation of Dust

Cementation of Cementation of DustDust

Young Hun YoonPeter Brimblecombe

University of East AngliaSchool of Environmental

Sciences, Norwich, NR4 7TJ, UK

Page 2: Cementation of Dust

0

2

4

6

0 25,000 50,000 75,000 100,000 125,000

Visitors/exposure period

/Gs

IMPACT OF VISITOR IMPACT OF VISITOR NUMBERSNUMBERSon DUST DEPOSITon DUST DEPOSIT

HCP

AEH

OPH

PREVIOUS WORK

2

Page 3: Cementation of Dust

PROBLEPROBLEMM

- High Humidity

- Biological attack- Chemical attack

- Physical behaviour

CEMENTATIONACCUMULATION

Some large particles disappearing!BECOME DEEPLY BECOME DEEPLY

EMBEDDED INTO FIBREEMBEDDED INTO FIBRE

RH change

3

Page 4: Cementation of Dust

100

200

300

400

30 35 40 45 50 55 60 65

RH

Ope

ning

/mic

rons

MOVING DUST!MOVING DUST! RH changeRH change

Measured by Dr D Bowden & Created by Prof. Peter Brimblecombe

4

Page 5: Cementation of Dust

DUST SEPERATIONDUST SEPERATION COLOUR CHANGECOLOUR CHANGE

Dust from proper left upper outer valance,KNOLE

Fibre

ParticlesOriginal Dust

18% w/w

82% w/w

5

Page 6: Cementation of Dust

A single particles A single particles adhered to adhered to

fibre surfacefibre surface

Many fine particles- fibre becomes dark

colour

DARK

COLOUR

COLOUR CHANGE

6

(a)

(b)

Page 7: Cementation of Dust

Excrement or egg from Excrement or egg from insect…?insect…?

7

Page 8: Cementation of Dust

BACTERIAL EXOPOLYMERSBACTERIAL EXOPOLYMERS

Silk fibers and bacteria after three months

of growth in high humidity.

SEMs: A. Tarnowski & C. McNamara Appl.Bio. DEAS Harvard University 8

Page 9: Cementation of Dust

CEMENTATION OF DUSTCEMENTATION OF DUST

Humidity and pollutants

may bind dust to

underlying surfaces

so sets cleaning frequency (Curtain from Eating Room)

Cementation?

9

Page 10: Cementation of Dust

EXPERIMENTEXPERIMENT Soil fines (63microns) + single

fibre or

Mixed with traces of salt and sugar in small dish

Exposed for about 3 months in HCP, Knole, Dover Tunnel

Lab work - 4 weeks exposure (at RH 35, 70, 80, 98%)

Weighing

10

Page 11: Cementation of Dust

HIGH HUMIDITY EXPOSUREHIGH HUMIDITY EXPOSURE

Concreted at High Humidity Knole & Dover Tunnel

Dust + sugar Dust + salt

11

Page 12: Cementation of Dust

COTTON AFTER A HUMID COTTON AFTER A HUMID WINTERWINTER

HCP Knole

12

Page 13: Cementation of Dust

0

1

2

3

4

5

Fibr

e W

eigh

t I

ncre

ased

(m

g)

RH 35%

RH 70%

RH 80%

RH 98%

Lab work: FIBRE WEIGHING

Soil + NaCl

Soil + Sugar Soil

weight 13

Page 14: Cementation of Dust

0

0.1

0.2

0.3

0.4

0.5

0.6

0 20 40 60 80 100 120

Humidity

Fibr

e W

eigh

t In

crea

sed

(mg)

Cotton Fibre + soil finesCotton Fibre + soil fines

Lab work: FIBRE WEIGHING

weight 14

Page 15: Cementation of Dust

weight

0123456789

10

Knole HCP Dover Tunnel

NaCL

Sucrose

Control

Low humidity in HCP shows small activity on cementation!

Exposures: FIBRE WEIGHING

15

Page 16: Cementation of Dust

Exposures: FIBRE WEIGHING

0

0.2

0.4

0.6

0.8

1

Knole HCP Dover Tunnel

Fibre

wei

ght

incr

ease

d (

mg)

Control

Control : without salt and sugar

weight 16

Page 17: Cementation of Dust

CONCLUSIONCONCLUSION

- Cementation control

- Cleaning frequency

&

20

Page 18: Cementation of Dust

SALT ENCRUSTATIONS

J.R.N. Tower Curing Works, 1880, Great Yarmouthreat Yarmouth

Fish washing box near salt store

in the building.

17

Page 19: Cementation of Dust

SALT ENCRUSTATIONS –

WOODEN BEAM WITH SALTWOODEN BEAM WITH SALT

0

10

20

30

40

50

60

70

conce

ntr

ati

on (

g/k

g)

Floor dust Storage Salt adhered towooden ceiling

Chloride

Sulphate

Nitrate

Salt adhered onto the wooden ceiling

Fish washing box and Plaster degraded of the wall.

x4

Dionex

18

J.R.N. Tower Curing Works, 1880, Great Yarmouthreat Yarmouth

Fish washing box near salt store

in the building.

Page 20: Cementation of Dust

Plate 2. Traditional dust flaps at Nostell Priory Library

DUST FLAPSDUST FLAPS : case study and : case study and applicationapplication

Plate1. Leather dust flaps at Library in Ickworth

House

Dust flap

(Credit: Katy Lithgow, NT)

19

Page 21: Cementation of Dust

CONCLUSIONCONCLUSION

- Cementation control

- Cleaning frequency

&

20


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