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An SF6 alternative gas, C4F7N mixed with CO2, has attracted great attention in recent years. The related experimental reports show that it has good insulation, thermal dissipation, switching performances and other characteristics. In theoretical research area, the thermophysical properties of plasma are of great significance to study the arc behaviour. However, for C4F7N, due to its complicated molecular...
The approach to creation of a refined math model of transient resistance electric arc that is suitable for analysis of relay protection operating and parameters monitoring in information signs multidimensional space, is outlined in the article. It describes experimental research of electric arc parameters, particularly determination of plasma conductivity for various temperatures. Obtained function...
The copper vapor resulting from electrode surfaces in arc devices, such as circuit breakers, may modify the characteristics of arc plasmas. The corresponding properties of plasmas contaminated by the metallic vapor are therefore needed to be determined before setting up physical models. In this paper, the equilibrium compositions, thermodynamic properties, transport coefficients, and combined diffusion...
The effect of dynamic percolation on the a.c. conductivity and permittivity of thermoplastic nanocomposites filled with 2.2 wt% of carbon nanotubes was studied. During isothermal annealing of the samples in the melt state a gradual and large increase of conductivity was evidenced with time. The profile of permittivity versus annealing time unexpectedly exhibited 2 maxima. This surprising feature was...
The interaction between triphenylphenoxy polyoxyethylenyl polyoxypropy-lene (PEP) and sodium dodecyl sulfate (SDS) were determinted using surface tension method. The mixed critical micelle concentration (CMC) values determined from the experimental data were used to calculate the molecular interaction parameters according to regular solution theory. The pseudoternary phase behavior of the mixed micromulsion...
This model simulates the process of continuous casting of a metal bloom from melted state. In order to optimize the dynamic soft reduction casting process in terms of casting rate and cooling, the thermal and fluid dynamic aspects of the process can be modeled. To get accurate results the melt flow field has to be modeled in combination with the heat transfer. The model includes the phase transition...
Based on thermo dynamical considering the phase changed regulation of frozen soil, this thesis deduces the frozen soil's differential equation correlating with temperature. The study by the finite-element method is simulated the temperature state of some area in the highway, analyze the variational regulation of temperature for the congelation wall, conclude the temperature's distributing regulation...
In order to elucidate the role of various ultrasonic effects on pH and conductivity of K2HPO4 solution, the dependencies of both properties on the solution temperature which rises due to ultrasonic thermo- effect are investigated. As the K2HPO4 solution is heated by the conventional method, the pH is linear with the reciprocal of thermodynamic temperature and the conductivity is linear with the temperature...
A dedicated platform was designed to study the transport and thermodynamic properties of various conductive nanowires (NWs). In this report, a Bi2Te3 nanowire with diameter d ~100 nm fabricated by AAO and chemical electrodeposition technique was carried out. The measured resistivity of the Bi2Te3 nanowires is about 4.3 ????-m, which is similar to the bulk value. The quality of nanowire was characterized...
Design, fabrication and testing of a micro thermal conductivity detector (muTCD) with a detection limit of 260 parts per billion (hexane in helium), no excess dead-volume, low power consumption, fast response time (150 musec) and low sensitivity to flow rate is described herein. Significantly, this muTCD is shown to have a linear response and high sensitivity across a 104-fold concentration range;...
The thermal cooling of the electronic components is generally implemented by a mechanical pump, which requires a minimal maintenance to ensure the reliability of the device. To solve this problem, it is proposed to replace the mechanical pump by a static one, for example an electro-osmotic (EO) pump. In this paper, we present the theory of the electro-osmosis phenomena, and a model of a porous EO...
As many thermoelectrics are in polycrystalline form with grain size down to nanometer scale, the size and boundary effect play important roles in their physical properties. In the paper we develop an approach to simulate the electronic and thermo-electric property of polycrystalline. In the first step, the polycrystalline texture is created from phase field method in a two dimension scale for simplicity...
Alkaline metal (AM) atoms filled CoSb3 skutterudites are synthesized by melting method and sintered by spark plasma sintering. The maximal filling fraction or filling fraction limit (FFL) of AM (AM=Li, Na, K, Cs) in CoSb3 are estimated experimentally and show good agreement with our previous calculations based on density functional method. The effect of thermodynamics properties on FFL, crystallographic...
The present work aims at studying the cooling performance of a thermoelectric device that integrated with integrated heat spreader (IHS) on a flip-chip plastic ball grid array (FC-PBGA) package. The new thermoelectric device herein is fabricated on the metal substrates by flip-chip assembly process. Thermal performance of the new package was comprehensive studied. The thermal resistances of IHS with/without...
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