Application of finite element method and heat conductivity transfer model for calculation of temperature distribution in receiver for dish-Stirling concentrating solar system is described. The method yields discretized equations that are entirely local to the elements and provides complete geometric flexibility. A computer program solving the finite element method problem is created and great n...

For the case of finite life-time broadening the standard Kubo-formula for the optical conductivity tensor is rederived in terms of Green’s functions by using contour integrations, whereby finite temperatures are accounted for by using the Fermi-Dirac distribution function. For zero life-time broadening, the present formalism is related to expressions well-known in the literature. Numerical aspe...

We find the combined effect of nonzero temperature and finite conductivity onto the Casimir force between real metals. Configurations of two parallel plates and a sphere (lens) above a plate are considered. Perturbation theory in two parameters (the relative temperature and the relative penetration depth of zero-point oscillations into the metal) is developed. Perturbative results are compared ...

Frozen green beans (Phaseolus vulgaris, L.) thermal conductivity (k) and heat capacity (Cp) were determined experimentally by a one dimensional finite difference (transient method) and differential scanning calorimetry, respectively. Thermal properties were also estimated by the inverse problem methodology (IPM). Heat capacity and thermal conductivity behaviour with temperature were modelled by...

The temperature dependence of electrical conductivity and conductivity anisotropy of FeCI3 doped stretch-oriented polyacetylene film at different doping levels were measured by using Montgomery technique. The increase of conductivity anisotropy upon doping is related to the aligned fibrillar structure and the interfibrillar contact effect. Weak temperature dependence, the slight decrease at low...

Ferromagnetic microwires are investigated as fundamental components to generate metamaterials with double negative parameters. Electric and magnetic responses are, respectively, based on the finite conductivity and ferromagnetic resonance of the wires that in turn depend on their chemical composition. Tuning properties of samples are investigated in terms of an applied magnetic field. The sampl...

We calculate the electrical conductivity in the early universe at temperatures below as well as above the electroweak vacuum scale, Tc ' 100GeV. Debye and dynamical screening of electric and magnetic interactions leads to a finite conductivity, σel ∼ T/α ln(1/α), at temperatures well below Tc. At temperatures above, W ± charge-exchange processes – analogous to color exchange through gluons in Q...

We discuss some recent results for the properties of doped antiferromagnets, obtained within the planar t-J model mainly by the finite-temperature Lanczos method, with the emphasis on the comparison with experimental results in cuprates. Among the thermodynamic properties the chemical potential and entropy are considered, as well as their relation to the thermoelectric power. At the intermediat...

In this paper, a two level finite difference scheme of Crank-Nicholson type is constructed and used to numerically investigate nonlinear temperature distribution in biological tissues described by bioheat transfer equation of Pennes’ type. For the equation under consideration, the thermal conductivity is either depth-dependent or temperature-dependent, while blood perfusion is temperature-depen...

The theory of the insulating state discriminates between insulators and metals by means of a localization tensor, which is finite in insulators and divergent in metals. In absence of time-reversal symmetry, this same tensor acquires an off-diagonal imaginary part, proportional to the dc transverse conductivity, leading to quantization of the latter in two-dimensional systems. I provide evidence...