the transport properties of liquids and gases through polymeric materialsplay a very important role in some areas of industrial applications. in thisstudy, natural rubber (nr)/caco3 composites were prepared by melt mixingmethod. by equilibrium swelling test, the transport process of toluene in the prepared natural rubber composites was investigated. the diffusion and transport of toluene throug...

Analysis of diffusion in a complex environment shows that the conventional diffusion equation based on Fick’s law fails to model the anomalous character of the diffusive mass transport observed in the field and laboratory experiments. New mathematical models of diffusive transport, different from Fick’s law, were proposed and validated in literature. In the present paper the examples of the equ...

Defeat and success of the competitive invasion of a populated area is described with a standard Lotka-Volterra competition model. The resident is adapted to the heterogeneous living conditions, i.e., its motion is modelled as space-dependent, so-called Fokker-Planck diffusion. The invader’s diffusion is taken as neutral Fickian. Furthermore, it is studied how multiplicative environmental noise ...

We consider the Maxwell-Stefan model of diffusion in a multicomponent gaseous mixture. After focusing on the main differences with the Fickian diffusion model, we study the equations governing a three-component gas mixture. Mostly in the case of a tridiagonal diffusion matrix, we provide a qualitative and quantitative mathematical analysis of the model. We develop moreover a standard explicit n...

In this paper, we prove the wellposedness of classical solutions for equation, deduced in [23]. It represents a reaction-diffusion model which spatial structure is maintained by means diffusive mechanism more general than Fickian diffusion. This generalized diffusion takes into account gradient (or energy) necessary to maintain pattern even single diffusing species.

Diffusion and sorption of Biodegradable blends of sodium alginate (SA) and lignosulphonic acid (LS) has been studied at room temperature by conventional weight gain experiments. The sorption studies of SA/LS blends are carried in pH medium of 7.4. The sorption data are used to evaluate the mass transfer coefficients such as intrinsic diffusion coefficient and permeation coefficient. It was obse...

A model for diffusion in liquids that couples the dynamics of tracer particles to a fluctuating Stokes equation for the fluid is investigated in the limit of large Schmidt number. In this limit, the concentration of tracers is shown to satisfy a closed-form stochastic advection-diffusion equation that is used to investigate the collective diffusion of hydrodynamically-correlated tracers through...

FTIR-ATR (Fourier transform infrared-attenuated total reflectance) spectroscopy and a conventional gravimetric sorption balance were used to study the diffusion of acetonitrile from the vapor phase in glassy cellulose acetate (CA). From the gravimetric experiments, the mass uptake kinetics were well described by a simple Fickian model. However, the experimental data from FTIR-ATR spectroscopy, ...