CORRECTION
CAPTURE OF SMALL PARTICLES BY LONDON FORCES FROM LOW-SPEED LIQUID FLOWS In this article by L. A. Spielman and S. L. Goren [ENVIRON. SCI. TECHNOL. 4, 135 (1970)], the following corrections and additions should be noted in the text:
N ~ + f i (Y)J;&aaplX, Y ) (Y' - 1)' The left-hand side of Equation 36, also on page 139, should read
At the top of page 136
where N P e = UaF/D, where a =
211
+
In addition, no explicit expressions for A s were given; Happel's cell model for a bed of spheres gives
1 (2/z)b(z)/Ko(z)l
Equation 14 on page 138 should read
h(H*)(H*
+ 2)2H*''
As =
where y
= 1
=
(:
-NAdp
=
~)1'3
e = fraction porosity
>>I Furthermore, the analysis should equally apply to aerosols, provided the limiting gap /z* given by Equation 14 is large compared to the mean free path of gas molecules. That is,
The interception number is defined as R
(1 -
+
a = fraction solids
Equation 18, also on page 138, should read
Y*
= a113 =
(1 - 79 3 3 1 --y - 75 - y6 2 2
ap/aFor ap/as IJh*
