Admixture diffusion in a two-phase random nonhomogeneous stratified layer

Vertical admixture diffusion has been considered in a layer with random nonhomogeneous two-phase stratified structure of the material. Different phase diffusion coefficients and phase densities have been taken into account as well as jump discontinuities of the diffusion coefficient at interphase boundaries. Averaging the obtained expressions for the admixture concentration has been done over the ensemble of sublayer configurations with equally probable distribution, and two particular cases of beta-distribution of phases in the body.