Diffusion Magnetic Resonance Imaging (dMRI) can be used to measure a time-dependent effective diffusion coefficient that can in turn reveal information about the tissue geometry. Recently a mathematical model for the time-dependent effective diffusion coefficient was obtained using homogenization techniques after imposing a certain scaling relationship for the time, the biological cell membrane...

Aerosol fire extinguishing agents have been recognized as an effective replacement of Halon. The uniform diffusion time and the effective concentration of the aerosol fire extinguishing agent are important parameters for putting out a fire. In this work, the effective concentration is derived based on the diffusion equation, and its variation with changing diffusion coefficient and diffusion ti...

We consider diffusion on substrate with a frozen disorder. While in ordered state the moving particle meets always the same energy barrier in amorphous state there is a more or less broad distribution of the height of barriers. The effective activation energy Eeff that controls the diffusion process is not equal to the average activation energy barrier. Actually, Eeff is the highest barrier tha...

This study focuses on the derivation of a general effective diffusion coefficient to describe the twodimensional (2D) diffusion in a narrow and smoothly asymmetric channel of varying width that lies on a curved surface, in the simple diffusional motion of noninteracting point-like particles under no external field. To this end we extend the generalization of the Kalinay-Percus’ projection metho...

background and purpose : there has been no report in which preoperative evaluation of adc for prediction of post therapeutic outcome was presented. the aim of our study was to retrospectively evaluation the use of the apparent diffusion coefficient (adc) for the prediction of malignancy and the outcome of malignant astrocytic tumors. methods: we reviewed mri of 26 male and 14 female patients wi...

This work deals with the short-time effective diffusion coefficient of charged and uncharged liposomes, measured ~as a function of the volume fraction! using fiber optic dynamic light scattering. Particularly, we are interested in the interplay between electrostatic and hydrodynamic interactions on the diffusion of these lipid vesicles. Regarding the charged liposome, it has been found that the...