Fig. 2
Model of substance migrating in and around a sample during an infinitesimal time, Δt. P S, saturated vapor pressure of solvent; P A, vapor pressure of solvent in the atmosphere; P C and P W, evaporation resistance pressure on the boundary between the atmosphere and wood elements (cell cavity and cell wall, respectively); K, surface evaporation coefficient; n C0 and n W0, moles of solvent in cell cavity and cell wall, respectively; n C1 and n W1, moles of solute in the cell cavity and cell wall, respectively; n W, number in moles of sorption sites of solution in the cell wall; x C0 and x W0, molar fractions of solvent in cell cavity and cell wall, respectively; x C1, and x W1, molar fractions of solute in cell cavity and cell wall, respectively; K 0 and K 1, solvent and solute diffusivity, respectively