Using ab initio molecular dynamics, the atomic structure and transport properties of eutectic Ga-In and Ga-In-Sn are investigated. The Kubo-Greenwood (K-G) and the Ziman-Faber (Z-F) formulations and the Wiedemann-Franz (W-F) law are used for the electrical and electronic thermal conductivity. The species diffusivity and the viscosity are also predicted using the mean square displacement and the...

Physical properties of building materials can be defined by material coefficients. The material coefficients examined were: coefficient of mean density, coefficient of specific heat capacity, coefficient of thermal conductivity, and coefficient of thermal diffusivity. Physical properties of a newly-developed material (polyurethane plaster), were subjected to nondestructive analysis. The same me...

In this work, the thermal diffusivity of single polyacrylonitrile (PAN) wires with diameters from 4.62 μm down to 324 nm is measured by using our recently developed transient electro-thermal technique. The wires span from 23 μm to 126.2 μm in our measurement. Since PAN wires are dielectric, a thin Au film is coated on the surface of the wires to make them conductive. In the experiment, a step c...

The thermal emission from a Ni–P disk substrate heated by a pulsed excimer laser is measured with nanosecond time resolution. A fast InGaAs photodetector is employed to capture the thermal emission signal. The spectral surface reflectivity is simultaneously measured in situ. The transient surface temperature is derived from the spectral thermal emission signal on the basis of Planck’s blackbody...

This paper presents a methodology and instrumentation system for the indirect measurement of the thermal diffusivity of a soil at a given depth from measuring its temperature at that depth. The development has been carried out considering its application to the design and sizing of very low enthalpy geothermal energy (VLEGE) systems, but it can has many other applications, for example in constr...

This study investigates the effects of two different catalytic activation techniques on the thermal performance of the flip-chip heat spreaders. The two activation techniques studied are thin nickel–copper strike and galvanic initiation. Thermal diffusivity and surface roughness of these heat spreaders were studied using the Nano-flash Apparatus and Infinite Focus Microscopy. High temperature s...

In this study the physical and thermal properties of baobab (Adansonia digitata) fruit pulp powder which are essential for designing engineering processes, material handling, storage, equipment design and fabrication were determined. The physical properties, namely, mean particle size, bulk density, true density and porosity were determined. Also, angle of repose and coefficient of friction wer...

The use of the photoacoustic effect in the investigation of firstand second-order phase transitions has been examined. Changes in the amplitude of the photoacoustic signal across the phase transition are compared with changes in thermal properties such as specific heat and thermal diffusivity. The systemsstudied include NaN02, TlN03, CsN03, NH4N03, BaTiO,, COO, Cu,HgI,, V 0 2 andV305. The curre...

Where ρ0, α0, ∆T , η, κ are dimensional reference values of density of the background mantle, thermal expansivity, temperature difference between core-mantle boundary and surface, reference viscosity at temperature T = 0.5 (non-dimensional), and thermal diffusivity, respectively. g and h are dimensional gravitational acceleration and thickness of mantle, respectively. 1 Chemical complexity of h...

New profile measurements have allowed the electron thermal diffusivity profile to be estimated from power balance in the Madison Symmetric Torus where magnetic islands overlap and field lines are stochastic. The measurements show that (1) the electron energy transport is conductive not convective, (2) the measured thermal diffusivities are in good agreement with numerical simulations of stochas...