Gas diffusion layers are essential components of proton exchange membrane fuel cell since the reactants should pass through these layers. Mass transport in these layers is highly dependent on porosity. Many of simulations have assumed, for simplicity, the porosity of GDL is constant, but in practice, there is a considerable variation in porosity along gas diffusion layers. In the present study ...

Experimental data of methane adsorption on two types of activated carbon have been carried out at pressures up to 35 bar and at ambient temperature. Adsorption equilibrium and kinetics data at high pressure were measured using a volumetric method. A theoretical model has been presented to calculate the amount of adsorbed gas on adsorbents in a cylindrical tank. In the model, gas enters the bed ...

In the absence of fractures, methane bubbles in deep-water sediments can be immovably trapped within a porous matrix by surface tension. The dominant mechanism of transfer of gas mass therefore becomes the diffusion of gas molecules through porewater. The accurate description of this process requires non-Fickian diffusion to be accounted for, including both thermal diffusion and gravitational a...

In the hydrodynamic regime, the evolution of a stochastic lattice gas with symmetric hopping rules is described by a diffusion equation with densitydependent diffusion coefficient encapsulating all microscopic details of the dynamics. This diffusion coefficient is, in principle, determined by a Green– Kubo formula. In practice, even when the equilibrium properties of a lattice gas are analytica...

In the hydrodynamic regime, the evolution of a stochastic lattice gas with symmetric hopping rules is described by a diffusion equation with densitydependent diffusion coefficient encapsulating all microscopic details of the dynamics. This diffusion coefficient is, in principle, determined by a Green– Kubo formula. In practice, even when the equilibrium properties of a lattice gas are analytica...

1. Introduction In this work, we utilized molecular dynamics simulations to investigate gas diffusion in realistic nanoporous carbon models. We will focused on how the structure of the porous medium affects the gas diffusion. The porous structural features of interests include topological defects, dangling bonds, size and connectivity of the pores. Through a mimetic virtual synthesis routine, p...

THE UPTAKE OF GASES SUCH AS OXYGEN, CARBON MONOXIDE, OR NITRIC OXIDE BY THE ERYTHROCYTE INVOLVES: (a) diffusion across the cellular membrane, (b) intraerythrocytic diffusion, and (c) chemical combination with hemoglobin. The aim of this investigation was to obtain data which would permit an analysis of each of these factors in limiting the rate of gas uptake. The initial over-all rate of uptake...

In the hydrodynamic regime, the evolution of a stochastic lattice gas with symmetric hopping rules is described by a diffusion equation with densitydependent diffusion coefficient encapsulating all microscopic details of the dynamics. This diffusion coefficient is, in principle, determined by a Green– Kubo formula. In practice, even when the equilibrium properties of a lattice gas are analytica...