Diffusivity Theoretical

Ganguly J. and Tirone M. (1999) Diffusion closure temperature and age of a mineral with arbitrary extent of diffusion theoretical formulation and applications. Earth Planet. Sd. Lett. 170, 131-140. 

Discussion of Experimental Results. Role of Diffusion. Small differences between cation and anion diffusion coeflBcients (differential diffusion) theoretically can account for the differential ion distribution even if the distribution coeflBcients themselves are assumed to be identical for cations and anions. If ionic distribution curves are determined mainly by differential diffusion, then little information can be obtained from them about the acceptability of different ions in the ice structure. 

Figure 2. Accurate values and Inonii s diffusion theoretic values for the nonescape probability from an infinite slab of thickness 2a, in which the scattering is isotropic and has a macroscopic cross section S.

D.W. Armstrong, T. Ward and A. Berthod, Micellar Effects on Molecular Diffusion Theoretical and Chromatographic Considerations, Anal Chem., 58 579 (1986). 

McKay, G. Al-Duri, B., and McKee, S., Development of solutions to two-resistance mass transport models based on external and pore diffusion Theoretical development and experimental results, Dev. Chem. Eng. Mineral Process., 1(2), 129-157(1993). 

As a consequence, the proper evaluation of segment diffusion at long diffusion times turned out to be more complicated than often anticipated. However, even with flip-flop spin diffusion theoretically taken into account, it is not possible to fit the formulas predicted by the tube/reptation model to the experimental data with respect to both the time and molecular weight dependences in a consistent way and without assuming unrealistic parameters [12]. 

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