A	Membrane Area
A 0	Knudsen flux coefficient
B 0	viscous flux coefficient
DAB	diffusivity of water vapor
ε	membrane porosity
Kb	Botzmann constant
σ	collision diameter
p	Mean pressure
JK	Vapor flux in the membrane resulting from Knudsen diffusion
R	universal gas constant
τ	Average tortuosity
T	Average temperature in the membrane pores
JM	Vapor flux in the membrane resulting from molecular diffusion
ya	mole fraction of the water vapor
${\delta }_i$	initial membrane thickness
${\delta }_0$	uncompacted membrane thickness
${\delta }_1$	compaction coefficient
η	gas viscosity