water vapor diffusion

water vapor diffusion

The process by which water vapor spreads or moves through permeable materials caused by differences in water vapor pressure.
References in periodicals archive ?
The diffusion coefficient of water vapor is three to four orders of magnitude smaller in lumens than water vapor diffusion coefficient in free water (Siau 1995).
Neopac The Tube'sPolyfoil[R] tubes offer uniqueprotection against light, air, water vapor diffusion and substance migration.
Neopac's Polyfoil[R] tubes offer unique protection against light, air, water vapor diffusion and substance migration.
VeoVa vinyl ester provides both alkaline and water resistance, while the water glass ensures good water vapor diffusion. DXV.4229 is suitable for use in indoor and outdoor paints and plasters.
Before C[O.sub.2] adsorption, this semicircle is attributed to the water vapor diffusion in high voltage condition.
Assessment results revealed that experts give priorities to commonly used criteria: costs of insulation, thermal, conductivity, water vapor diffusion resistance and durability.
Other important materials are mineral aggregates; in this issue investigations for rock texture and composition of it are studied to understand the water vapor diffusion, as well as the vapor sorption in composite materials.
For the water vapor diffusion in the moistened pores, the effective thermal conductivity ([k.sub.pd]) is determined from the thermal conductivity due to water vapor diffusion ([k.sub.diff]), which takes into consideration the heat transfer due to the evaporation occurring at the warm side of the pore, and condensation at the cold side.
The 15 selected papers discuss such topics as hydraulic testing, flow rate measurement, water vapor diffusion through polymeric barriers, measuring interface transmissibility, peel and shear test comparison and geosynthetic clay liner shear strength correlation, boundary effects of the gripping system on internal shear strength tests, and the geosynthetic concrete composite mat.
Where [D.sub.v] = 2 3.4 x [10.sup.-6] [([T.sub.k]/273).sup.2.3], is the water vapor diffusion coefficient; [P.sub.sat] = 610.8 x exp (17.08085 x T/234.175 + T), saturation vapor pressure; [P.sub.amb] is the ambient pressure; [h.sub.v] is the latent heat of evaporation; [R.sub.v] is the gas constant.
Water vapor transport was characterized by water vapor diffusion permeability [delta] (s), diffusion coefficient of water vapor D ([m.sup.2]/s), and water vapor diffusion resistance factor [mu] (--).