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A B ST R

A C T

J E F F R E Y JO H N SO

N

.

D

ete r

m i

n at

io n

o

f R

e s

p i

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M

a s s

C

o n c entration

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sin

g

a

H i g h

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o

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r

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ra ct

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U

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A R K E R R E I ST

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s a

l l

o

w

s t

h

e

p

a rt

i

c

l

e s o

f i

nte r e st

to

p

a s s t

h

r o u

g h

t

h

e

d

e v

i

c e a n

d

co

l l

ect o n a

fi l

ter

f

or

q

u ant

i fi

cat

i

o n .

I

n t

h

e o r

y

, a c

y

c

l

o n e

c a n

b

e

d

e s

i g

n e

d

to exc

l

u s

i

v e

l y p

er

m i

t a

l l p

art

i

c

l

e s

b

e

l

o

w

o n e s

i

z e ran

g

e to

b

e c o

l l

e cte

d

.

T h i

s

i

n str u

m

e nt c a n

h

a v e t

h

e s o

l

e

p

u r

p

os e o

f p

r o v

i d i

n

g

r es

p i

ra

b l

e

m

a s s c o nce ntrat

i

on .

T h i

s s

p

e c

i

a

l i

zat

i

on

p

rov

i d

e s t

h

e

b

e st

m

et

h

o

d f

or

p

ro

d

u c

i

n

g

c o n s

i

ste nt r e s

p i

ra

b l

e

m

a s s

c o n c e ntr at

i

on .

T h

e r e

f

o r e

, a c

y

c

l

on e o

f

s o

m

e s

i

z e,

d

es

i g

n, an

d

c o

m p

o s

i

t

i

on s

h

o u

l d

pr o v

i d

e t

h

e stu

d

y

w i

t

h

t

h

e

m

o st a c c u r ate a n

d

r e

l i

a

b l

e sta n

d

a r

d

.

A

c

y

c

l

o n e's

p

a rt

i

c

l

e s

i

z e-s e

l

e ct

i

v e r a n

g

e c a n va r

y d

e

p

e n

d i

n

g

o n

i

ts s

i

z e,

d

e s

i g

n,

a n

d

c o n str uct

i

on

m

ate

ri

a

l.

T h

e s

i

z e o

f

a c

y

c

l

o n e r e

f

e r s to

i

ts

i

nte r n a

l d i

a

m

ete r.

T h i

s

i

n te r n a

l

c

h

a

m b

e r

i

s

w h

e r e

m

o st o

f

t

h

e s

i

z e s e

l

e ct

i

n

g

ta

k

e s

p l

a c e.

G

e n e r a

l l y

(8)

m

y

T

h

e

i

nte r n a

l d

e s

i

gn o

f

t

h

e cyc

l

o n e,

i

s

q

u

i

te

i m p

o rta nt.

A i

r a n

d p

a rt

i

c

l

e s e nte r

i

n

g

t

h

e cyc

l

o ne

m

ust

p

a s s t

h

r o u

g h

t

h

e

i

nn e r c

h

a

m b

e r to a c c e

l

e r ate

l

ar

g

e r

p

a rt

i

c

l

e s to t

h

e

i

nter

i

o r

w

a

l l

s,

w h

ere t

h

e

y

c a n

b

e co

l l

e cte

d

.

A p

ote nt

i

a

l l

y s e v e r e

p

ro

b l

e

m

o cc u rs

w h

e n

p

art

i

c

l

e s a re a

l l

o

w

e

d

to

b y p

a s s t

h

e

i

n ner c

h

a

m b

er an

d g

o stra

i g h

t t

h

ro u

g h t h

e c

y

c

l

on e.

W

i

t

h

out t

h

e c

i

r c u

l

a r acc e

l

erat

i

o n t

h

e

l

ar

g

e r

p

a rt

i

c

l

e s

w i l l

n ot

b

e re

m

ove

d

,

i

nste a

d

t

h

ey

w i l l b

e c o

l l

e cte

d

on t

h

e

f

i

l

te r a n

d i

n cor r e ct

l y

a s su

m

e

d

to

b

e res

p i

ra

b l

e.

M

ore over,

l

ar

g

e r

p

a rt

i

c

l

e s c o ntr

i b

ute

m

u c

h m

o r e

m

a s s

p

e r

p

a rt

i

c

l

e t

h

a n s

m

a

l l

e r

p

art

i

c

l

e s.

A f

e

w

l

a r

g

e

p

a rt

i

c

l

e s

i

n c or r e ct

l

y a s s

i g

n e

d

a s r e s

p i

r a

b l

e, c a n

d

r a st

i

c a

l l y

a n

d i

n co r r e ct

l y i

n c re as e t

h

e

c o

l l

e cte

d

m

a ss.

T h

er e

f

ore t

h

e cyc

l

on e c

h

o s e n

m

u st

h

ave a n en

g i

n e er e

d b

ar r

i

er,

p

r e v e nt

i

n

g l

a r

g

e

p

a rt

i

c

l

e

b yp

a s s.

T h

e

m

ater

i

a

l f

ro

m

w h i

c

h

a c

y

c

l

on e

i

s

m

a

d

e

i

s a v a r

i

a

bl

e t

h

at

h

a s r e c e

i

v e

d

c o n s

i d

e ra

b l

e at te nt

i

o n ,

d

ue to t

h

e

h i g h l y

s u s

p

e cte

d i

n

f l

u e n c e o

f

e

l

e ctro stat

i

c c

h

ar

g

e.

T h

e

i

s s u e o

f

c

h

ar

g i

n

g

e

ff

ects

h

a s

l

e a

d

to t

w

o

g

en e r a

l

t

y p

e s o

f

constru ct

i

on

m

ater

i

a

l

s,

con

d

u ct

i

n

g

o r s e

m i

c o n

d

u ct

i

n

g

(

m

eta

l

)

an

d

n on c on

d

u ct

i

n

g

(

n

y l

o n

)

.

S

e v e r a

l

stu

d i

e s

h

av e

b

ee n c ar r

i

e

d

ou t t

h

at c o

m p

ar e n

y l

o n a n

d m

eta

l

c

y

c

l

one s.

A

c o

m

m

on

p

r o

b l

e

m w i

t

h

t

h

e s e

stu

d i

e s

i

s t

h

at t

h

e

y

u s e

d

t

h

e

h

or

i

zonta

l

e

l

u tr

i

ator,

w h i

c

h

e

m

u

l

ate s t

h

e

B

r

i

t

i

s

h

M

e

d i

c a

l

R

es ea r c

h C

o u n c

i l

(

B

M

R C

)

c u r v e, a s t

h

e

f

r a

m

e o

f

r e

f

e r e n c e.

W

i

t

h

t

h i

s

f

r a

m

e o

f

r e

f

erenc e, c on c

l

u s

i

o n s c o n c ern

i

n

g

t

h

e

A C G I H

d

e

f i

n

i

t

i

o n o

f

re s

p i

ra

b l

e are

d i f fi

c u

l

t to

d

e r

i

v e.

N

e ve rt

h

e

l

e s s, tr e n

d

s an

d

re

l

at

i

ve

di f f

ere n ce s are r eve a

l

e

d

.

S

as s-

K

orts a

k

et a

l

. c o

m p

a r e

d

t

h

e

10 m

m

n

y l

on to a

9 m m

a

l

u

m

i

n u

m

c

y

c

l

one

w

i

t

h

t

h

e

h

o r

i

z onta

l

e

l

utr

i

ato r as t

h

e stan

d

a r

d f

o r c o

m p

ar

i

s o n .(

3)

T h

e te st a e

r oso

l

s

w

e re s

i l i

c a

an

d w

o o

d d

u sts.

T h

e s

i l i

c a

w

a s a c o

m m

e r c

i

a

l l y

ava

i l

a

b

l

e

d

u st s

i

e v e

d w i

t

h

a

3 2 5

m

e s

h

.

T h

e

w

o o

d d

u st

w

a s

m

a n u

f

a ctu r e

d b

y

p l

a c

i

n

g

a

b

e

l

ts a n

d

e r o n a

p

i

e c e o

f m

a

h

o

g

a n

y w

o o

d

.

A b l

e n

d

e r

w

a s u s e

d

a s t

h

e a e r o s o

l

ge n e r ato r.

T h

e e

f f

e ct o

f

a e r o s o

l

ty pe a n

d

r e

l

at

i

v e

(9)

T h

at stu

d y f

oun

d

t

h

at

i

n a

l l

c a s e s t

h

e n

y l

on c

y

c

l

on e un

d

e r sa

m p l

e

d

,

w h i l

e t

h

e

m

eta

l

c

y

c

l

o n e o v e r s a

m

p l

e

d

.

T h

e

m

eta

l

c

y

c

l

o n e a

l w

a

y

s re

p

or te

d

a

h i g h

e r re s

p i

r a

b l

e

d

ust

c o n c entr at

i

o n t

h

a n t

h

e n

y l

o n c

y

c

l

one.

T h

e stu

d y

a

l

so

f

ou n

d

t

h

at

w h

en s a

m p l i

n

g w

oo

d

d

u st,

d if f

e r

i

n

g

r e

l

at

i

v e

h

u

m i d i

t

i

e s

d i d

n ot s e e

m

to c

h

a n

g

e t

h

e s a

m p l i

n

g

resu

l

ts.

B

ut

w h

en

s

i l i

c a

d

u st

w

a s us e

d

a tr e n

d

e

m

e rge

d

.

A

s t

h

e r e

l

at

i

ve

h

u

m i d i

t y

w

ent u

p

, t

h

e ny

l

on c

y

c

l

o n e

p

a s s e

d

a

h i g h

e r c o nc en tr at

i

o n o

f

s

i l i

c a

p

art

i

c

l

e s.

T h i

s tr e n

d w

as n ot

f

oun

d i

n t

h

e

m

eta

l

c

y

c

l

one.

T h

e r e a s on

f

o r t

h i

s

d i

s c r e

p

a n c

y p

r o

b

a

b l y i

n vo

l

v e s e

l

e ctr ostat

i

c c

h

ar

g i

n

g

e

f f

e cts

,

w h i

c

h

ar e

m

o r e a

p p

ar e nt

i

n

l

o

w h

u

m i d i

t

y

e nv

i

ron

m

e nts.

T h

e a

p p

a r e nt

d i f f

e r ence

b

et

w

ee n

w

o o

d

an

d

s

i l i

c a

d

u st, a c cor

d i

n

g

to t

h

e a ut

h

ors,

i

s

d

u e to

h

u

m i

d

i

t

y i

n t

h

e

w

o o

d

r e

d

u c

i

n

g

e

l

e ctr o stat

i

c e

f f

e cts.

T h

e

S

as s-

K

o rts a

k

stu

dy

s

h

o

w

e

d

t

h

at t

h

e

m

eta

l

cyc

l

o n e c ons

i

ste nt

l

y overs a

m p l

e

d

,

w h i l

e t

h

e n

y l

o n c

y

c

l

one c o n s

i

ste nt

l y

u n

d

ers a

m

p l

e

d

.

B

ut

, t

h i

s c o n c

l

u s

i

o n c an n ot

b

e r eac

h

e

d w h

e n t

h

e

A C G EH

cr

i

ter

i

on

i

s t

h

e r e

l

e v a nt sta n

d

a r

d

.

T h i

s stu

d y

us e

d

a

h

o r

i

zonta

l

e

l

utr

i

ato r

w h i

c

h

s

i

z e-s e

l

e cts a c c o r

d i

n

g

to t

h

e B

M

R C

c r

i

te r

i

a.

W

h

at c a n

b

e c o n c

l

u

d

e

d i

s t

h

at t

h

e

m

eta

l

cy c

l

o n e c o n s

i

ste nt

l

y r e

p

o rte

d

a

h i g h

e r c o n c e ntr at

i

o n t

h

a n t

h

e n

y l

on

c

y

c

l

o ne.

W

i

t

h

ou t a r e

l

e v ant

A C G I H

re

l

ev an t sta n

d

ar

d

,

d

ete r

m

i

n

i

n

g w h i

c

h i

s "

c or r e ct"

i

s

v e r

y d i f fi

c u

l

t.^ ^)

V

er

m

a et a

l

. c o n

d

ucte

d

a

h

a r

d

ro c

k

m

i

n

i

n

g f i

e

l d

stu

d y

c o

m p

a r

i

n

g

t

h

e 1

0 m m

n

y l

o n c

y

c

l

o n e to t

h

e

SI

M

PE D S

a n

d B C I R A m

eta

l

c

y

c

l

o n es.

^

A g

a

i

n, t

h

e r e

f

e r e n ce

s a

m p l

er

w

a s t

h

e

h

o r

i

z o nta

l

e

l

u tr

i

ato r

w h i

c

h p

e r

f

o r

m

s a c c o r

d i

n

g

to t

h

e

B

M

R

C

c r

i

te r

i

a. In t

h i

s stu

d y

t

h

e n

y l

on c

y

c

l

one r e

p

orte

d

a

l

o

w

er r e s

p

i

ra

b l

e c onc entrat

i

o n c o

m p

a re

d

to t

h

e

m

eta

l

c

y

c

l

on es,

b

ut t

h

e

d i f f

e r en c e

w

a s n ot stat

i

st

i

c a

l l y

s

i g

n

i f i

c a nt.

S

a

m

p l i

n

g

w

a s

c o n

d

u cte

d i

n

m i

n e s

w i

t

h h i g h h

u

m i di

t

i

e s.

G i

v e n t

h

e

i

n

f

or

m

at

i

o n

i

n t

h

e

S

a ss

-

K

o rts a

k

et a

l

. stu

dy

c on c er n

i

n

g h

u

m i d i

t

y

,

w

e

w

o u

l d

e x

p

e ct t

h

e n

y l

o n c

y

c

l

o n e to re

p

o rt r e

l

at

i

v e

l y

h i g h

e r c o n c e ntr at

i

ons,

d

u e s o

l

e

l y

to

h

u

m i d i

t

y

e

f f

ects.

S

o, t

h

e stat

i

st

i

c a

l l y

nons

i g

n

i f

ic ant

d i ff

e r e n c e

i

s

p

r o

b

a

b l

y c o r r e ct, g

i

v en t

h i

s

h

u

m i d

env

i

r o n

m

e nt.

^

A

n ot

h

e r c o n c e r n

i

s t

h

e

(10)

l i g h

y g

p

, ^

m

5 |

i

m

f

or t

h

e

B

M

R C

.

A l

s o

, t

h

e

B

M

R C d

e

f i

n

i

t

i

on

h

a s a s

m

a

l l

er

p

art

i

c

l

e s

i

ze ran

g

e, ~

0

to

7

1 n m

, t

h

an t

h

e

A C G I H d

e

fi

n

i

t

i

on ,

~0 to 1 0 ^

m

.

W

A

n

i

ne s c a

p

a

b l

e er ro r o cc u r s

w h

en

r e s

p i

r a

b l

e

d

u st c o n c e ntr at

i

o n s,

f

r o

m

s a

m p l

e r s con

f

or

m i

n

g

to

d i f f

e r e nt cr

i

te r

i

a, a r e

c o

m p

a r e

d

.

K

n

i g h

t et a

l

. a

l

s o c o

m

p

are

d

t

h

e

10

m m

n

y l

o n c

y

c

l

o n e to t

h

e

B C I R A

m

eta

l

c

y

c

l

o n e, a n

d

ot

h

e r s

i

z e

- se

l

e ct

i

v e s a

m p l

e r s .(

^>

A g

a

i

n t

h

e r e

f

e r e n c e s a

m p l

e r

w

a s a

h

o r

i

z o nta

l

e

l

utr

i

ato r.

T h i

s stu

d y f

o i

m d

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M

R

C

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ter

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. T

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a r e

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l

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y

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w

e

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.

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e

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y

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12 5

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)

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h

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h

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l B C I R A i

s

b

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y

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er

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M

R C

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's c r

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T h

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f

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(11)

to

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A C G I H

cr

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to

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E

n e r

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o

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(

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)

m

e

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art

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cr

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w h i

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b

as e

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B

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c r

it

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A C G I H d

e

fi

n

it

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p l

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t

i

s

b

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d

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e cu

m

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b

a

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m

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er

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the c r

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a "

p

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" to the

m

a c

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ne

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A C G I H

cr

i

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;

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cr

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l

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s a n

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su s

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m p l i

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p

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s

i

n

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s s u

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y

c

l

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b

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l

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i

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c

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, a n

d

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p

ort a c onc en trat

i

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h

an a ctu a

l

.

T h i

s c onc er n

i

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l i m i

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d w i

th

a cyc

l

o n e c o n str u cte

d

o

f

a c o n

d

u ct

i

n

g m

ate r

i

a

l

. T

h

e c

y

c

l

o n e us e

d i

n t

h i

s stu

d y w

a s

c onstr u cte

d

o

f

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d

u ct

i

n

g m

ater

ia

ls

,

f

o r

t h

e a

f

o re

m

ent

i

o n e

d

r ea s on s.

A l

t

ho u

g h

t

h

e

A C G I H

s

p

e c

ifi

e

d

c

y

c

l

o n e a s o

f

t

h i

s

w

r

i

t

in

g i

s a

10

-

m m

n

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(12)

c u ,

l y

p

s u

g g

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d

a s t

h

e

5 0

%

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T h

e c

y

c

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p

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T h i

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H

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n a

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p

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Y

et c a r e

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ust

b

e ta

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d

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m p

ar

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,

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f d i f f

e r e nt a e r o s o

l

s.

D i f f

e r e nt a e ro so

l

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r o

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e

p

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d i

n

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on t

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i

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d i

str

i b

ut

i

o n s.

F

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h

e t

h i

s stu

dy

t

h

e r e

l

at

i

v e

d i f f

e r e n ce s

b

et

w

e en s a

m p l

e r s

w

e r e t

h

e

m

a

j

o r c o n c e r n .

T h

u s a r

i g i d q

u a nt

it

at

i

v e a s s e s s

m

e nt

i

s not

n e e

d

e

d

.

T h

e c

h

o s en stan

d

ar

d f

o r c o

m p

ar

i

son

in

t

h i

s stu

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s t

h

e

10

-

m

m

stee

l

c

y

c

l

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p

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d

u ce

d b

y

B G I

.

T h

e s

p

e c

i fi

c

m

o

d

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nu

m

b

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is

t

h

e

B G I

-

4

.

T h

e

d i

m

e ns

i

o n s o

f

t

h

e

c

y

c

lo

n e

p

ro

d

u c e a cu t at

4

.

0 m i

cro

m

ete rs

, c o n sisten t

w i

t

h

t

h

e n e

w A C G I H

cr

i

ter

i

a.

T h

e

B G I

-4

h

as a n

i

n n e r

b

a r r

i

e r to

p

r e v e nt o r

m i

n

i m i

z e

p

a rt

i

c

l

e

b y p

a s s.

I

ts stee

l

c o n str u ction

m i

n

im

i

z e s e

f f

e cts

d

u e to e

l

e ctrostat

i

c c

h

ar

g i

n

g

.

T h i

s c

y

c

l

o n e

i

s n ot s

p

e c

i f i

e

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t

h

e

A C G IH

no

w

,

b

ut

g i

v e n

i

ts a

d

v a nta

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a

y b

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p

e c

i f i

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d i

n t

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e

f

utu re.

T h i

s c

y

c

lo n

e

(13)

8

M

E T H O D D E S C R I P T I O

N

A N D

T

H E O R

Y

T h

e

p

ro

p

os e

d

m

et

h

o

d

c o n s

i

st o

f

a

h i g h

v o

l

u

m

e a

i

r s a

m p l

e,

w i

t

h

a s u

b

s e

q

u e nt

p

a rt

i

c

l

e s

i

ze an a

l y

s

i

s u s

i

n

g

a

l i q

u

i d

s e

d i

m

e ntat

i

o n te c

h

n

i q

ue.

A h i g h

v o

l

u

m

e a

i

r s a

m

p l

e r

i

s e

q

u

i p p

e

d w i

t

h

a sta n

d

a r

d 8

x

10 i

n c

h g l

a s s

fi b

e r

fi l

te r

, a n

d

a

l l

o

w

e

d

to r u n unt

i l

a

l

a

y

e r o

f

p

a rt

i

c

l

e s a c cu

m

u

l

ate s.

O

n c e t

h i

s "

c a

k

e"

h

a s

f

or

m

e

d

t

h

e s a

m p l

e

i

sr e a

d

y

f

or an a

l

ysis.

T h

e

f

or

m

at

i

on o

f

t

h

e c a

k

e

is

an a

b

s o

l

ute n e c e s sit

y f

or se v e r a

l

re as o n s.

C

a

k

e

f

or

m

at

i

o n

i

nsur e s t

h

at t

h

e r e

i

s enou

g h

r e

m

o v a

b l

e

m

ate r

i

a

l f

or ana

l

y s

i

s.

W

i

t

h

out su

f fi

c

i

en t

m

ate r

i

a

l

t

h

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d i m

entat

i

on tec

h

n

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w i l l

lo s e

c ons

i d

era

b l

e a c c ura c

y

, o r

m

a

k

e an a

l y

s

i

s

i m p

o s s

i b l

e

F

u rt

h

e r

m

o r e, c a

k

e

f

o r

m

at

i

on e nsu r e s t

h

at t

h

e

m

ate r

i

a

l

r e

m

ov e

d

f

o r ana

l

ys

i

s

i

s

r e

p

r e s e ntat

i

v e o

f

t

h

e a ero s o

l

's size

d i

str

i b

ut

i

o n.

A l

t

h

ou

g h

t

h

e

g l

a s s

fi b

er

fi l

te r

m

a

y h

a v e

an e

f f

ic

i

enc

y

c

l

o s e to on e

w i

t

h i

n

i

t

i

a

l

u s e, a

l l p

art

i

c

l

e s c a

p

tu re

d

c a n n ot

b

e r e

m

o v e

d f

o r

ana

l

ys

i

s at t

h i

s

p

o

in t

.

T h

e s

m

a

l l

e r

p

a rt

i

c

l

e s te n

d

to e

m b

e

d d

e e

p w i

t

h i

n t

h

e

fi l

te r

m

a

k i

n

g

r e

m

o v a

l d i f f

i c u

l

t

A

n a

l y

s

is

w i

t

h

out t

h

e s e

p

a rt

i

c

l

es

w

ou

l d p

ro

d

u c e an a

l

te r e

d d i

str

i b

ut

i

on .

So

, as t

h

e

p

ores

i

n t

h

e

fi l

te r

b

e c o

m

e

fi l l

e

d

, t

h

e c a

k

e

f

or

m

s.

T h

e s

m

a

l l

e r

p

art

ic

l

e s

w i l l

e

m b

e

d i

n t

h

e c a

k

e, a s op

p

o s e

d

to t

h

e

fi l

te r

it

s e

l f

.

T h

u s,

w h

en the c a

k

e

i

s r e

m

o v e

d f

o r

a n a

l y

s

i

s,

i

t c o nta

i

n s t

h

e s

m

a

l l

e r

p

a rt

i

c

l

e s o

f

c o n c e rn .

A f

ter s a

m p l

e c o

l l

ect

i

o n, t

h

e

p

a rt

i

c

l

es are r emove

d f

r o

m

t

h

e

fi l

te r

b y

s cra

p i

n

g

t

h

e

c a

k

e

w i

t

h

a

d

u

l l

e

d g

e.

W

h

e n s c r a

p i

ng t

h

e

p

a rt

i

c

l

e s

f

r o

m

t

h

e

fi lt

e r

, c ar e

m

u st

b

e ta

k

e n n ot

to r e

m

o v e

fi l

te r

m

ater

i

a

l

.

T h i

s

m

ate r

i

a

l

contr

i b

ute s

m

a s s t

h

at c an

b

e

m i

sta

k

e n

l y

q

u ant

i fi

e

d

a s aer oso

l i

ze

d p

art

ic

l

e s.

P

revent

i

n

g

t

h i

s

i

nv a r

i

a

b l y

re su

l

ts

i

n

m

ater

i

a

l

r e

m

a

i

n

i

n

g i

n t

h

e

fi l

te r.

Y

et, t

h i

s

is

not a co n c e r n a s

lo

n

g

as a su

ff i

c

i

ent c a

k

e

h

a s

f

or

m

e

d

.

T h

e r e

m

o v e

d

p

art

ic

l

es ar e t

h

e n

p l

a c e

d

i

nto a s e

d i m

e ntat

i

on

p i p

et te

f

or

f

r a ct

i

o n at

i

o n.

T h

e

f

r a ct

io n a

t

io n

m

et

h

o

d

w

as

d

e v e

lo

p

e

d b

y R

e

i

st a n

d C

r e e

d

.(

' °)

T h i

s

m

et

h

o

d i

s

b

a s e

d

o n

p

a rt

i

c

l

e s et t

l i

n

g

ve

l

o c

i

t

y i

n a

m

e

d i

u

m

,

w

ate r

f

o r t

h i

s stu

d y

. T

h

e

set t

l i

n

g

v e

l

o c

i

t

y i

s

d

eter

m i

n e

d b y S

to

k

e s'

l

a

w

.

P

a rt

i

c

l

e s o

f d i f f

e rent

d i

a

m

ete rs

w i l l

r e a c

h

d i f f

e r e nt te r

m

i

n a

l

s et tl in

g

v e

l

o c

i

t

i

e s

(14)

g

g i

p

d i

a

m

eter

p

art

i

c

l

e s.

T h i

s re

l

at

i

ons

h i p i

s r e

p

res e nte

d b y

t

h

e

f

o

l l

o

w i

n

g f

or

m

u

l

a :

'

4

(P

p - P

j

g t

c

,

^

'

^

d

=

p

art

i

c

l

e

d

i

a

m

ete r

(

c

m

)

S

to

k

e s'

d i

a

m

ete r

|

x = v

i

s c o s

i

t

y

o

f

m

e

d i

u

m

(

g

c

m

^*

s e c'^

)

; . y =

d i

sta n ce

p

art

i

c

l

e

h

a s

f

a

l le

n

(

c

m

)

Pp

=

d

e n s

i

t

y

o

f p

a rt

i

c

l

e

(

g

c

m

-3

)

p

„ =

d

ens

i

t

y

o

f m

e

d i

u

m

(

g

c

m

^^

)

g

= a c c e

l

e r at

i

o n o

f du e

to

g

r a v

i

ty

(

c

m

s ec ^

)

t = t

i m

e

(

s e c

)

C

j , = s

l i p

c or r e ct

i

on

f

a ctor

,

1 f

or t

h

e s

i

ze ran

g

e o

f

c o nce rn

T h

e

d i

a

m

ete r

p

r o v

i d

e

d b y

e

q

uat

i

on

(

1

)

i

s t

h

e

S

to

k

e s'

D

i

a

m

eter .( " )

T h

e

S

to

k

es'

di

a

m

ete r

i

s t

h

e "

d i

a

m

ete r o

f

a s

p h

e r e o

f

t

h

e sa

m

e

d

e ns

i

t

y

a s t

h

e

p

art

i

c

l

e

i

n

q

u est

io

n

h

av

i

n

g

t

h

e sa

m

e s et t

l in

g

v e

l

oc

i

t

y

as t

h

at

p

a rt

i

c

l

e, "(i ^)

Fo r t

h

e

p

u r

p

o s e o

f

t

h i

s stu

d y w

e

n e e

d

an a e ro

d y

na

m i

c

d i

a

m

ete r, a s o

pp

os e

d

to a

S

to

k

e s'

d i

a

m

ete r.

T h

e a ero

d y

n a

m i

c

d ia

m

ete r

is

t

h

e "

d ia

m

ete r o

f

a u n

i

t

d

e n s

i

t

y

s

p h

er e

(

d

e n s

i

t y = 1

g /

c

m

^

)

h

a v

i

n

g

t

h

e s a

m

e

a ero

d y

n a

m i

c

p

ro

p

e rt

i

e s a s t

h

e

p

a rt

i

c

l

e

i

n

q

ue st

i

on, "

(^ i)

T h i

s state s t

h

at a s

l

o n

g

a s t

h

e

te r

m i

n a

l

s et t

l i

n

g

v e

l

o c

i

t

i

e s o

f

t

w

o

p

a rt

i

c

l

e s a r e t

h

e s a

m

e, r e

g

a r

d l

e s s o

f p h

ys

i

c a

l

s

i

z e

a n

d/

o r s

h

a

p

e, t

h

e

y w i l l h

a v e

i d

ent

i

c a

l

a e ro

d y

n a

m i

c

d i

a

m

ete rs.C

^)

T

o c o nvert t

h

e

S

to

k

e s'

d i

a

m

ete r to an a e r o

d y

na

m i

c

d i

a

m

ete r, t

h

e

S

to

k

e '

s

d ia

m

eter

i

s

m

u

l

t

i p l i

e

d b y

t

h

e s

q

u are

r o ot o

f

t

h

e

p

art

i

c

le

's

d

en s

i

t

y

.

T h i

s tra n s

f

or

m

at

i

o n

i

s n ec e s s ar

y w h

en co

m p

ar

i

n

g

t

h

e

s e

d i m

e ntat

i

o n te c

h

n

i q

u e's r e su

l

ts to t

h

e cyc

l

o n e's r e s u

l

ts,

b

e c a u s e t

h

e cyc

l

o ne's

p

er

f

o r

m

a nc e

i

s

b

a s e

d

on a ero

d y

na

m i

c

d i

a

m

eter.

T h

e

p

a rt

i

c

l

e s o

f p

r

i m

a r

y i

nte rest

i

n t

h

e a na

l

ys

i

s

w

er e c o

m p

o s e

d

o

f q

u a rtz, t

h

u s t

h

e

a

d

e n s

i

t

y

o

f 2

.6 5

g /

c

m

w

a s u s e

d i

n e

q

u at

i

o n

(

1

)

.

T h

e u s e o

f

o n e

d

e n s

i

ty to

d

e s c r

i b

e a

l l

pa rt

i

c

l

e s

i

n t

h

e s a

m p l

e r e s u

l

ts

in

a n e r ro r.

R

e

i

st an

d C

r ee

d

,

d

e ve

l

o

p

e r s o

f

t

h

e

(15)

10

tr u e

p

art

i

c

l

e

d

en s

i

t

i

es

w

e r e

2

.0

g/

c

m

or

g

r e ater.

T h

e us e o

f

a 2.

6 5 g /

c

m

v a

l

ue

f

o r

d

e n s

it

y w i l l

r e su

l

t

in

s

i g

n

i fi

c an t er ro r

w i

t

h p

art

ic

l

es

h

a v

i

n

g

a

d

e n s

i

t

y l

o

w

er t

h

a n 2.

0

g

/

c

m

^

.

G i

v e n t

h

e

p

art

i

c

le

s

iz e

i

n

f

o r

m

at

i

o n

,

d

ete r

m i

n e

d b y

e

q

u at

i

o n

(

1

)

, the

p

e r c e ntage o

f

p

art

i

c

l

e s at a ny

d

e s

i

r e

d

s

iz e

ca n

b

e

d

e te r

m

i

n e

d

.

T h is

is

a c c o

m p l i

s

h

e

d

u s

i

ng a

s e

d i m

e ntat

io n

p i p

et te,

f

i

l le

d w i

th wa te r an

d

t

h

e

m

ate r

i

a

l

o

f

c o nc e r n.

T h

e se

d i

m

e ntat

i

on

p i p

et te c o n s

i

sts o

f

a c

y l i

n

d

e r a n

d

a

p i p

ette

w i

th a 3-

w

a

y

sto

p

c o c

k

t

h

at c a n

b

e

fi

xe

d

at a

g i

v e n

h

e

i g h

t

i

ns

i d

e t

h

e cy

l i

n

d

e r.

A ft

e r a

d d i

t

io

n o

f w

ate r an

d m

ate r

i

a

l

, t

h

e s

y

ste

m i

s

s

h

a

k

e n to e n s u re c o

m p l

ete

m i

x

i

n

g

.

A

t t

i

m

e

i

nte rva

l

s

,

d

eter

m i

n e

d b y

e

q

uat

io n

(

1

)

10

m

l

a

l i q

u ots a r e r e

m

o v e

d

a n

d p l

a c e

d in

to

p

re

w

e

i

g

h

e

d d

ry

i

ng

p

a n s.

O

n c e

d

r

y

, t

h

e

m

a s s

r e

m

a

in

i

n

g

o n t

h

e

p

a n s

i

s us e

d

to

p

r o

d

u c e t

h

e

p

art

i

c

l

e s

iz e

d is

tr

i b

ut

i

o n.

T h

e an a

l y

s

is

w i l l

p

r o

d

u c e a p

l

ot o

f p

art

i

c

le

s

i

z e v e r su s

p

er c e nt

l

es s t

h

a n t

h

at s

iz e

.

A

n exa

m p l

e

i

s

p

ro v

i d

e

d

in

F i g

. 1.

T h

e

p

e rce nta

g

e o

f p

art

i

c

l

e s at an

y d

e sir e

d

size an

d

s

m

a

l le r

c a n

b

e

f

o u n

d f

ro

m

t

h is

p l

ot.

T h

e r e a

d

e r

i

s a

d

v

i

s e

d

to c o n s u

l

t t

h

e o r

i g i

n a

l

stu

d y b

y

R

e

is

t a n

d C

r e e

d

,

f

o r

a

d d it

io

n a

l d

eta

i l

s.

A

s

l i g h

t

m

o

d i fi

cat

io n

o

f

t

h

e

R

e

is

t an

d C

ree

d

m

et

h

o

d w

a s n ee

d

e

d f

or t

h i

s stu

d

y.

T h

ey state, "

T h

e

w

e

i g h

t o

f

e a c

h

s a

m p l

e

is

e x

p

r e s s e

d

a s a

p

e r c entage o

f

t

h

e

fi

r st s a

m

p

l

e

d

r a

w

n to

g i

v e t

h

e

p

e r c e nta

g

e o

f

t

h

e su s

p

e n

d

e

d p

a rt

ic

u

l

ate s

h

a v

in

g p

art

i

c

l

e s

iz e s

e

q

u a

l

to

o r s

m

a

l l

e r t

h

a n t

h

at

g i

v e n

b

y e

q

u at

i

on

(

1

)

. " (' °)

T h is s

tates that a

l l f

r act

io n s a r e

b

a s e

d

o n

the

fi

r st a

l i q

uot that

is

d

ra

w

n.

T h i

s

p

r o c e

du r e

s e e

m

e

d

to

p

r o

du c e

a n e r r o r

b

et

w

e en t

h

e

H V

a n

d

c

y

c

l

on e

m

etho

d f

o r

d

eter

m i

n

i

n

g

r es

p i

ra

b l

e

m

a s s c o nc e ntr at

i

on .

T h

e a

l

te r n at

iv

e

m

et

h

o

d

u s e s t

h

e

m

a s s o

b

ta

i

ne

d f

ro

m

a t

h

e or et

i

ca

l 10

m

l

a

l i q

u ot o

f

the

in

i

t

i

a

l

c o nce ntr at

io n

, a s t

h

e

f

r a

m

e o

f

r e

f

er e n c e.

T h

e

i

n

it

i

a

l

co n c entrat

i

o n r e

f

e rs to t

h

e

m

as s o

f m

ate r

i

a

l in

the tota

l

v o

lu

m

e o

f w

atex.

T h i

s

f

r a

m

e o

f

r e

f

er enc e

i

s n e e

d

e

d

, a s

o

p p

o s e

d

to the

fi

r s t

dr

a

w

n a

l i q

u ot,

b

e c a u s e t

h

e s e s a

m p l

e s c o nta

i

n ve r

y l

a r

g

e

g

r a

i

n s.

T h

e s e

la r

g

e

g

r a

in s

,

w h

e n a n a

l y

z e

d w i

t

h

t

h

e s e

d i m

e ntat

i

o n tec

h

n

i q

ue,

f

a

l l q

u

i

c

k l y

a n

d

h

ave no c

h

an c e o

f b

e

in

g

d

ra

w

n u

p

in

t

h

e

f

u

References

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