among various reported membrane-based gas separation processes, the best explanation is generally achieved by the solution-diffusion model. the main factors in this model are the solubility and diffusivity of permeationcomponents through the membrane. the prediction of permeability and diffusivity in multicomponent gas permeation as well as the separation evaluation equilibrium and kinetic inte...

2 Macroscopic modeling 5 2.1 Concentration measures, mixture velocity and diffusion fluxes . . . . . . . . 5 2.2 Species transport equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 Fick model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.4 Limits of Fick model: osmotic diffusion, reverse diffusion and diffusion barrier 8 2.5 Maxwell-Stefan mo...

In the present work, the extraction of zinc from a sphalerite concentrate using sodium nitrate as an oxidant in a sulfuric acid solution was investigated. The effective parameters such as the temperature, sulfuric acid and sodium nitrite concentrations, stirring speed, particle size, and solid/liquid (S/L) ratio were analyzed. The dissolution rate increased with increase in the sulfuric acid an...

INTRODUCTION At high b-values (e.g., ≥1,500 s/mm), it is well known that diffusion-induced MR signal loss in the brain tissue exhibits anomalous behavior that cannot be described by a mono-exponential function. This phenomenon has been attributed to tissue heterogeneity manifested by cellular structures, cell membranes, and/or intraand extra-cellular spaces [1]. Over the past few years, a numbe...

A spectral color reproduction method is proposed based on a vector error diffusion method. A low-dimensional linear model is used to approximate reflectance spectra, and the vector error diffusion is performed in a score vector space of the linear model. A suitable set of primary colors is also selected from oil colors. Presented method performed better than conventional colorimetric vector err...

is investigated, where f is a bi-stable reaction-term and D(v) is a diffusion coefficient with changing sign, modeling aggregating-diffusing processes. We provide necessary and sufficient conditions for the existence of traveling wave solutions and classify them according to how or if they attain their equilibria at finite times. We also show that the dynamics can exhibit the phenomena of finit...

Fleming-Viot processes are a wide class of probability-measure-valued diffusions which often arise as large population limits of so-called particle processes. Here we invert the procedure and show that a countable population process can be derived directly from the neutral diffusion model, with no arbitrary assumptions. We study the atomic structure of the neutral diffusion model, and elicit a ...