The problem of magnetohydrodynamic flow and heat transfer of a viscous, incompressible, and electrically conducting fluid past a semi-infinite unsteady stretching sheet is analyzed numerically. The problem was studied under the effects of Hall currents, variable viscosity, and variable thermal diffusivity. Using a similarity transformation, the governing fundamental equations are approximated b...

Thermal properties of compost bulking materials affect temperature and biodegradation during the composting process. Well determined thermal properties of compost feedstocks will therefore contribute to practical thermodynamic approaches. Thermal conductivity, thermal diffusivity, and volumetric heat capacity of 12 compost bulking materials were determined in this study. Thermal properties were...

Porous silicon (PSi) layers were formed on a p-type Si wafer. Six samples were anodised electrically with a 30 mA/cm² fixed current density for different etching times. The samples were coated with a 50-60 nm gold layer and annealed at different temperatures under Ar flow. The morphology of the layers, before and after annealing, formed by this method was investigated by scanning electron micro...

Knowledge of the thermal conductivity of boron carbide is necessary o evaluate its potential for high temperature thermoelectric energy conversion applications. We have measured the thermal diffusivity of hot -pressed boron carbide B1_xCx samples as a function of composition (0.1 < x < 0.2), temperature (300 K to 1700 K) and temperature cycling. These data in concert with density and specific h...

We present a method to measure the in-plane thermal conductivity of thin films by the laser flash technique. The method uses a well-defined structure for the analysis. We have realized the structure by conformal deposition of ZnO films of different thicknesses using atomic layer deposition onto a 20 μm thick ion track etched polycarbonate membrane as substrate. By using this procedure we could ...

Thermal transport properties of solid Bi-Cu alloys have been investigated over a wide composition range and temperature between 25 250 °C. The flash method was used to determine thermal diffusivity. diffusivity discovered decrease continuously with increasing bismuth content. indirect Archimedean the density at obtained results show that studied decreases slightly as copper content increases. c...

The Mixed Scale Diffusivity Model, originally developed in the case of the differentially heated cavity, is applied to compute turbulent Rayleigh-Bénard flow in an infinite fluid layer at Pr = 0.71 for a large range of Rayleigh numbers (6.3 × 10 – 2 × 10). The effect of this SGS modelling, which adjusts locally the SGS diffusivity to the thermal scales of the flow and results in variable PrSGS ...

Transient grating spectroscopy was applied to measurements of sound velocity and thermal diffusivity in binary mixture solutions of carbon dioxide (CO(2)) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF(6)]) along the saturated line of CO(2) at 40 degrees C up to 20.0 MPa. The sound velocity decreased more than 10% by increasing the pressure to 10 MPa, and the pressure effect was...

Mixtures of BaCO3, ZnO and TiO2 powders, with molar ratio of 1:2:4, were mechanically activated for 20, 40 and minutes in a planetary ball mill. The resulting powders were compacted into pellets and isothermally sintered at 1250 °C for 2h with a heating rate of 10 °C/min. X-ray diffraction analysis of obtained powders and sintered samples was performed in order to investigate changes of the pha...