Study of ``Non-Fickian'' Diffusion Anomalies through Time Lags. II. Simpler Cases of Distance- and Time—Distance-Dependent Anomalies

Publisher Website
Google Scholar
Abstract
Study of the properties of the time‐lag parameters defined in Part I is here extended to the case where the solubility (S) and thermodynamicdiffusion (DT ) coefficients are functions of position X in the direction of flow. Such studies permit the detection and, characterization of this type of ``non‐Fickian'' diffusion behavior. This is still possible, though in a more limited way, when S and DT also depend on time. The properties of the time‐lag parameters mentioned above have been investigated in some detail for cases amenable to analytical treatment; namely when S and DT are functions either of X alone or of both diffusant activity, a and X, provided that a, X are separable in the appropriate functions. Similarly, it is shown that when S and DT also depend on time t a limited study of both kinds of ``non‐Fickian'' anomaly is possible, if a, t are separable from X in S(a, X, t), DT (a, X, t).

This publication has 9 references indexed in Scilit: