The microstructure of a porous medium and physical characteristics of the solid and the fluids that occupy the pore space determine the macroscopic transport properties of the medium. The computation of macroscopic properties from the rock microtomography is becoming an increasingly studied topic. The transport properties are especially difficult to determine at the microscopic scale. In this p...

In this paper we investigate the combined effect of nonstationarity in log hydraulic conductivity and the presence of boundaries on flow in heterogeneous aquifers. We derive general equations governing the statistical moments of hydraulic head for steady state flow by perturbation expansions. Due to their mathematical complexity, we solve the moment equations by the numerical technique of finit...

introduction: groundwater is the largest resource of water supplement and shortages of surface water supplies in drought conditions that requires an increase in groundwater discharge. groundwater flow dependson the subsurface properties such as hydraulic gradient (water table gradient or head loss in artesian condition) and hydrodynamic coefficients. the flow treatment is analyzed with an accur...

The main point of this paper is to propose a non-local three-dimensional hydraulic conductivity full tensor upscaling algorithm and code. The algorithm is capable of transforming very refined cell conductivity models into coarse block conductivity models for quick and accurate solution of the groundwater flow equation. Flow rate and hydraulic head gradient are the variables used to relate the o...

The Hall conductivity in the magnetic-field-induced spin-density-wave (FISDW) state of the quasi-onedimensional organic conductors (TMTSF)2X at a finite temperature is calculated. The temperature dependence of the Hall conductivity is found to be the same as the temperature dependence of the Fröhlich current of a regular charge/spin-density wave. Predicted dependence σxy(T ) can be verified exp...

In the present study, the effect of porosity on the cathode microstructure (50:50 wt. % LSM: YSZ) of a Solid Oxide Fuel Cell (SOFC) has been examined. A 3-D finite element method for Mixed Ionic and Electronic Conducting Cathodes (MIEC) is presented to study the effects of porosity on cell performance. Each microstructure was realized using the Monte Carlo approach with the isotropic type of gr...

The electrical conductivity value of the human skull is important for biophysics research of the brain. In the present study, the human brain-to-skull conductivity ratio was estimated through in vivo experiments utilizing intra-cranial electrical stimulation in two epilepsy patients. A realistic geometry inhomogeneous head model including the implanted silastic grids was constructed with the ai...

In three-dimensional QED, a quantum Hall effect occurs in the absence of any magnetic field. We give a simple and transparent explanation. In solid-state physics, the Hall conductivity for rational magnetic flux is expected to be given by a Chern number. In our field-free situation, however, the conductivity is ±1/2 in natural units. We explain why the integrality of the conductivity breaks dow...

We consider a d-dimensional disordered harmonic chain (DHC) perturbed by an energy conservative noise. We obtain uniform in the volume upper and lower bounds for the thermal conductivity defined through the Green-Kubo formula. These bounds indicate a positive finite conductivity. We prove also that the infinite volume homogenized Green-Kubo formula converges.

thin bonded films have many applications in antireflection and reflection coating, insulating and conducting films and semiconductor industries. thermal conductivity is one of the most important parameter for power packaging since the thermal resistance of the interconnections is directly related to the heat removal capability and thermal management of the power package. the defects in material...