1. In pure gelatin solutions the conductivity of the solution increases with increasing concentrations, regardless of the hydrogen ion concentration. The actual value of the specific conductivity is greater at that reaction where the degree of ionization is greater. 2. The addition of gelatin in increasing concentrations to a 0.6 per cent sodium chloride solution affects the conductivity of tha...

The generalized Kubo-Greenwood formula for conductivity is used for an explicit calculation of the perpendicular conductivity of GaAs-AlGaAs (crystalline III-V) heterostructures. Two cases are discussed (a) evaluation of DC conductivity at low temperatures and (b) AC conductivity at any temperature T. The method involves the causal Green’s function and relates the conductivity with superlattice...

– We study the electron thermal transport in granular metals at large tunnel conductance between the grains, gT 1, and not too low a temperature, T > gTδ, where δ is the mean energy level spacing for a single grain. Taking into account the electron-electron interaction effects, we calculate the thermal conductivity and show that the Wiedemann-Franz law is violated for granular metals. We find t...

The compounds, lanthanium chromite, lanthanium magnetite and lanthanium ferric oxide were prepared through sol-gel methods in powdered form, then calcinated, peletized, and sintered at various temperatures. Electrical conductivity of these compounds was measured at various temperatures. The effectiveness of strontium as a dopant on electrical conductivity was also investigated. Electrical condu...

We study the effect of disorder on the intrinsic anomalous Hall conductivity in a magnetic two-dimensional electron gas with a Rashba-type spin-orbit interaction. We find that anomalous Hall conductivity vanishes unless the lifetime is spin-dependent, similar to the spin Hall conductivity in the nonmagnetic system. In addition, we find that the spin Hall conductivity does not vanish in the pres...

The thermal conductivity is calculated with the Helfand-moment method in the Lennard-Jones fluid near the triple point. The Helfand moment of thermal conductivity is here derived for molecular dynamics with periodic boundary conditions. Thermal conductivity is given by a generalized Einstein relation with this Helfand moment. The authors compute thermal conductivity by this new method and compa...

Thermal conductivity of the Earth's lower mantle greatly impacts the mantle convection style and affects the heat conduction from the core to the mantle. Direct laboratory measurement of thermal conductivity of mantle minerals remains a technical challenge at the pressure-temperature (P-T) conditions relevant to the lower mantle, and previously estimated values are extrapolated from low P-T dat...

In this paper, we investigated the effective thermal conductivity of three dimensional nanocomposites composed of randomly distributed binary nanoparticles with large differences (contrast ratio) in their intrinsic (bulk) thermal conductivity. When random composites are made from particles with very different thermal conductivity (large contrast ratio), a continuous phase of high thermal conduc...

Electroencephalography (EEG) is a non invasive imaging technique that measures the effect of the electric activity of active brain regions, called sources, through values of the electric potential furnished by a set of electrodes placed at the surface of the scalp. A fundamental problem there is the inverse problem of source localization which aims at locating the sources of the electric activi...

Electrically conductive polymer composites filled with carbon black can exhibit the mechanical behavior of a polymer and metallic electrical conductivity. Unfortunately, excessive amounts of carbon black can produce brittle films and too little carbon black can result in low conductivity. Composite conductivity can be dramatically improved by using latex as the matrix starting material. Latex p...