4.4.2 Impact of Pressure on the Diffusivity Coefficient In general, the diffusion coefficient is inversely proportional to pressure. This is also an observed fact: gas production rates from coal seams tend to increase as the reservoir pressure goes down. This is because of increased diffusivity as...
Both ovaries were manually three-dimensionally segmented on b = 1500 s/mm2; apparent diffusion coefficient (ADC) calculation and kurtosis fitting (Dapp, Kapp) were performed. Differences in ADC, Dapp and Kapp between time points and groups were compared using repeated measures ANOVA and t-test ...
A very simple approach is based on the Dzugutov contribution developed on model fluids in which a universal (i.e. species-independent) connection relates the pair excess entropy of a liquid to its reduced diffusion coefficient. However its application to "real" liquids still remains uncertain ...
Product cO DO (permeation constant PO) for an oxygen partial pressure pO2 of 2.1 × 104 Pa and diffusion coefficient DO of oxygen in palladium vs. reciprocal temperature 1/T Full size image With the oxygen solubilities cO given in the work of Jehn and Grallath [4] for 2.1 × 104 Pa...
}_{d0}(\frac{{D}_{d}}{{D}_{l}}-1)}\)is the proportionality constant that is related to the dislocation densities of two end members of the diffusion couple without an AMF, the radius of the dislocation pipe, the dislocation diffusion coefficient and the lattice diffusion coefficient. ...
whereMis the molecular weight andV0is the molar volume of the sample;Tis the temperature at which density is computed andαLis the linear thermal expansion coefficient. Thus, experimentally measured temperature dependent thermal expansion coefficient is essential for accurate estimation of actualα(αact...
Theoretical analysis of the effect of isotropy on the effective diffusion coefficient in the porous and agglomerated phase of the electrodes of a PEMFC C. Pacheco Romeli Barbosa L. C. Ordoñez Scientific Reports (2024) The Computational Study of Fluid Diffusion through Complex Porous Media in...
Even the Li diffusion coefficient, which is underestimated by the Nernst–Einstein equation, is several orders of magnitude higher than those of conventional oxide and sulfide electrode materials. Analyzing the diffusion pathways using a classical force field calculation suggests that stabilizing the high...
Fig. 3. Example of the concentration vs. time curves for small molecules diffusing in water. (a) APAP (b) CAF (c) TRP. For legend, AS: analytical solution; NS: numerical solution. Table 3. Diffusion coefficients of APAP, CAF, and TRP in water. Technique Diffusion coefficient (D) (10...
A gas diffusion layer for use in fuel cells comprises a fiber and non-fiber material in a ratio such that the water vapor diffusion transport resistance is greater than 0.8 s/cm mea