Divalent cations and group-specific chemical modifiers were used to modify sodium efflux in order to probe the molecular structure of sodium channels in dog red blood cells. Hg++, Ni++, Co++, and PCMBS (parachloromercuribenzene sulfonic acid), a sulfhydryl reactive reagent, induce large increases in Na+ permeability and their effects can be described by a curve which assumes 2:1 binding with th...

A global nonlinear stability analysis is performed for a couple-stress fluid layer heated from below saturating a porous medium with temperature-pressure dependent viscosity for different conducting boundary systems. Here, the global nonlinear stability threshold for convection is exactly the same as the linear instability boundary. This optimal result is important because it shows that lineari...

In this work a glass micromodel which its grains and pores are non-uniform in size, shape and distribution is considered as porous medium. A two-dimensional random network model of micromodel with non-uniform pores has been constructed. The non-uniformity of porous model is achieved by assigning parametric distribution functions to pores throat and pores length, which was measured using ima...

Electric permittivity and magnetic permeability of linear passive dispersive medium were defined using the circuit equation of an electrically small antenna (scatterer) with resonant and antiresonant properties. It was shown that the average macroscopic energy stored by the scatterers is proportional to frequency derivative of the input admittance of corresponding antenna. It was found that the...

The outflux of calcium from vesicles of sarcoplasmic reticulum is controlled by the concentration of ionized calcium in the medium. In a calcium-free medium calcium outflux is at a minimum provided ATP and Mg are present. If they are removed calcium outflux becomes rapid and has a rate constant similar to that of outflux during steady-state (40)Ca-(45)Ca exchange with saturating calcium concent...

In this paper, the effect of magnetic field on double-diffusive convection in couple-stress fluid saturating a porous medium is considered. By applying linear stability theory and normal mode analysis method, a necessary condition is derived which states that the viscoelastic double-diffusive convection at marginal state, cannot manifest as stationary convection if the thermal Rayleigh number R...

Subsurface hydraulic properties are mainly governed by the heterogeneity of the porous medium considered. Our work aims at characterizing the asymptotic dispersion coefficients for highly heterogeneous permeability fields triggered by advection and constant local dispersion-diffusion. We have developed a fully parallel software for simulating flow and transport. We have compared two well-known ...

We derive exact expressions for so-called "void" bounds on the trapping constant gamma and fluid permeability k for coated-sphere and coated-cylinder models of porous media. We find that in some cases the bounds are optimal. In these instances, exact expressions are obtained for the relevant length scale that arises in the void bounds, which depends on a two-point correlation function that char...