A macrohomogeneous model is presented for a porous electrode that includes coupled potential and concentration gradients with linear kinetics. The equations are solved to obtain an analytical expression for the impedance of a porous electrode. Complex plane plots are presented that illustrate two well-defined arcs: a kinetic arc and a diffusion arc with their time constants far apart. The effec...

An analytical equation is derived for total triple phase boundary length per unit volume (LTPB) in an isotropic uniform random microstructure of LSM/YSZ composite cathode. The equation is applicable to YSZ and LSM particles of any convex shapes and size distributions. The equation explicitly relates LTPB to the shapes, mean sizes, coefficient of variation (a measure of the spread in a size dist...

In this article, we develop a set of partial differential equations describing the flow of a dusty fluid in variable porosity media. The developed equations take into account the effect of the porous microstructure on the flowing phases. We presented and overview of the equations governing the flow of a dusty gas in various type media, including that in naturally occurring porous media. Numeric...

In this paper, natural frequencies and dynamic response of thick beams made of saturated porous materials resting on viscoelastic foundation are investigated for the first time. The beam is modeled using higher-order beam theory. Kelvin-voight model is used to model the viscoelastic foundation. Distribution of porosity along the thickness is considered in two different patterns, which are symme...

The current research of nonlinear seepage theory of shale-gas reservoir is still in its infancy. According to the characteristics of shale gas in adsorption-desorption, diffusion, slippage and seepage during accumulation, migration and production, a mathematical model of unstable seepage in dual-porosity sealed shale-gas reservoir was developed while considering Knudsen diffusion, slip-flow eff...

Radiation characteristics of fused quartz containing bubbles (10 % porosity) are determined using inverse method based on theoretical and experimental bi-directional transmittances and reflectances. The Discrete Ordinates Method is used to solve the RTE. The internal and external interfaces are assumed to be optically smooth. The importance of the choice of the interpolation law has been shown,...

the goal of this laboratory study is to investigate the effect of pore shapes on seismic wave velocities in carbonate rocks under reservoir conditions. in this research, 41 core plugs of carbonate rocks from oil fields of the southwest of iran were prepared. the compressional and shear wave velocities were measured in both dry and brine saturated samples under several pressures especially reser...