scholarly journals Theoretical Study of a Thermophysical Property of Molten Semiconductors

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Fathi Aqra ◽  
Ahmed Ayyad
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
High Temperature ◽  
Theoretical Calculation ◽  
Theoretical Approach ◽  
Theoretical Study ◽  
Molten Silicon ◽  
Surface Tension Data ◽  
Silicon And Germanium ◽  
Calculated Temperature Dependence

This paper deals with theoretical approach to surface tension of molten silicon and germanium, and contributes to this field, which is very important. A theoretical calculation for determining the surface tension of high-temperature semiconductor melts, such as molten silicon and germanium, in the temperature range 1687–1825 K and 1211–1400 K, respectively, is described. The calculated temperature-dependence surface tension data for both Si and Ge are expressed as and (mJ m−2), respectively. These values are in consistence with the reported experimental data (720–875 for Si and 560–632 mJ m−2 for Ge). The calculated surface tension for both elements decreases linearly with temperature.

scholarly journals High Temperature Assessment of K-Tl Binary Liquid Alloy

2020 ◽  
Vol 6 (2) ◽  
pp. 20-25
Author(s):  
N. Panthi ◽  
I. B. Bhandari ◽  
R. C. Pangeni ◽  
I. Koirala
Keyword(s):  
Surface Tension ◽  
High Temperature ◽  
Thermodynamic Properties ◽  
Liquid Alloy ◽  
Theoretical Study ◽  
High Concentration ◽  
Temperature Dependent ◽  
Binary Liquid Alloy ◽  
Binary Liquid ◽  
Exponential Interaction

Theoretical study of thermodynamic properties of binary liquid Potassium-Thallium alloy at temperatures 798 K, 1000 K, 1200 K and 1400 K have been analyzed as a function of concentration by considering temperature dependent exponential interaction parameters in the framework of R-K polynomials. The viscosity and surface tension of the alloy have been studied by BBK model and improved derivation of Butler equation respectively. The study provides the information of moderately interacting as well as segregating nature at the low concentration of Thallium and ordering nature at high concentration of Thallium and the viscosity and surface tension of the alloy decrease with increase in temperature.

Dependence of the Equation of State in Surface Tension Prediction by the Theory of Capillarity

2009 ◽  
Author(s):  
Aaron P. Wemhoff
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Vapor Pressure ◽  
Interfacial Tension ◽  
Saturated Vapor ◽  
Saturation Pressure ◽  
Liquid Density ◽  
Fluid Models ◽  
Vapor Density ◽  
Surface Tension Data

The theory of capillarity was originally developed by J. D. van der Waals to provide a means of predicting interfacial (surface) tension data using saturation pressure and liquid-vapor density data. This theory was recently extended to the Redlich-Kwong, Soave-Redlich-Kwong, and Peng-Robinson fluid models. The latter two equations of state are more advanced than the Redlich-Kwong model in that they use an acentric factor to predict saturated vapor pressure values more in agreement with experimental data. However, the agreement in the predicted interfacial tension values is worse for the latter two models compared to the Redlich-Kwong model. This study features a sensitivity analysis to show that the predicted interfacial tension values are more sensitive to vapor density than liquid density and vapor pressure, and that increasing the vapor density reduces the corresponding predicted interfacial tension value. Furthermore, all three fluid models tend to overpredict interfacial tension when experimental data are applied in their predictive equations. This study finds that the reason why the simpler Redlich-Kwong model predicts better interfacial tension values than the two advanced models is because the former overpredicts vapor density moreso than the two advanced cubic fluid models, and this in turn reduces the prediction of interfacial tension to make its value more comparable to experimental data.

scholarly journals Revisiting Kelvin equation and Peng–Robinson equation of state for accurate modeling of hydrocarbon phase behavior in nano capillaries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ilyas Al-Kindi ◽  
Tayfun Babadagli
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Equation Of State ◽  
Phase Behavior ◽  
Pore Radius ◽  
Microfluidic Chips ◽  
Tight Sandstone ◽  
Kelvin Equation ◽  
Rock Samples ◽  
Robinson Equation

AbstractThe thermodynamics of fluids in confined (capillary) media is different from the bulk conditions due to the effects of the surface tension, wettability, and pore radius as described by the classical Kelvin equation. This study provides experimental data showing the deviation of propane vapour pressures in capillary media from the bulk conditions. Comparisons were also made with the vapour pressures calculated by the Peng–Robinson equation-of-state (PR-EOS). While the propane vapour pressures measured using synthetic capillary medium models (Hele–Shaw cells and microfluidic chips) were comparable with those measured at bulk conditions, the measured vapour pressures in the rock samples (sandstone, limestone, tight sandstone, and shale) were 15% (on average) less than those modelled by PR-EOS.

Multislip in f.c.c. crystals a theoretical approach compared with experimental data

1982 ◽  
Vol 30 (8) ◽  
pp. 1627-1637 ◽  
Author(s):  
P. Franciosi ◽  
A. Zaoui
Keyword(s):  
Experimental Data ◽  
Theoretical Approach

scholarly journals Effect of the Fe2O3 Addition Amount on Dephosphorization of Hot Metal with Low Basicity Slag by High-Temperature Laboratorial Experiments

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 417
Author(s):  
Wenkui Yang ◽  
Jian Yang ◽  
Yanqiu Shi ◽  
Zhijun Yang ◽  
Fubin Gao ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Theoretical Calculation ◽  
Oxygen Potential ◽  
Oxygen Activity ◽  
Hot Metal ◽  
Rich Phase ◽  
Addition Amount

In this paper, the influence of the Fe2O3 addition amount on the dephosphorization of hot metal at 1623 K with the slag of the low basicity (CaO/SiO2) of about 1.5 was investigated by using high-temperature laboratorial experiments. With increasing the Fe2O3 addition amount from 5 to 30 g, the contents of [C], [Si], [Mn] and [P] in the hot metal at the end of dephosphorization are decreased and the corresponding removal ratios increase. In dephosphorization slags, the phosphorus mainly exists in the form of the nCa2SiO4–Ca3(PO4)2 solid solution in the phosphorus-rich phase and the value of coefficient n decreases from 20 to 1. Furthermore, the oxygen potential and activity at the interface between the slag and hot metal are increased. When the oxygen potential and the oxygen activity at the interface are greater than 0.72 × 10−12 and 7.1 × 10−3, respectively, the dephosphorization ratio begins to increase rapidly. When the Fe2O3 addition amount is increased to 30 g, the ratio of the Fe2O3 addition amount to theoretical calculation consumption is around 175%, and the dephosphorization ratio reaches the highest value of 83.3%.

Gaseous CdCl2 and PbCl2 adsorption by limestone at high temperature: mechanistic study through experiments and theoretical calculation

2021 ◽  
pp. 149669
Author(s):  
Jianrui Zha ◽  
Zhicheng Zhu ◽  
Yaji Huang ◽  
Peter T. Clough ◽  
Zhipeng Xia
Keyword(s):  
High Temperature ◽  
Theoretical Calculation ◽  
Mechanistic Study

Explanation of the Influence of Inflow Air Content on the Lift of Cavitating Hydrofoils

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Lift Coefficient ◽  
Cavity Surface ◽  
Air Bubbles ◽  
Incoming Flow ◽  
Fluid Density ◽  
Air Content ◽  
Theoretical Results ◽  
Good Agreement

According to several known experiments, an increase of the incoming flow air content can increase the hydrofoil lift coefficient. The presented theoretical study shows that such increase is associated with the decrease of the fluid density at the cavity surface. This decrease is caused by entrainment of air bubbles to the cavity from the surrounding flow. The theoretical results based on such explanation are in a good agreement with the earlier published experimental data for NACA0015.

Residual Stress Measurement and Simulation of 3C-SiC Single and Poly Crystal Cantilevers

2010 ◽  
Vol 645-648 ◽  
pp. 865-868 ◽  
Author(s):  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Daniel Alquier ◽  
M. Italia ◽  
Andrea Severino ◽  
...  
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Stress Measurement ◽  
Bulk Material ◽  
Raman Shift ◽  
Silicon Substrates ◽  
Free Standing ◽  
Element Analysis ◽  
Micro Fabrication ◽  
Sic Films

The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on either bulk material or on the SiC surface. The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro-fabrication. In this work a comparison between single crystal and poly crystal 3C-SiC micro-machined structures will be presented. The free-standing structures realized (cantilevers and membrane) are also a suitable method for residual field stress investigation in 3C-SiC films. Measurement of the Raman shift indicates that the mono and poly-crystal 3C-SiC structures release the stress in different ways. Finite element analysis was performed to determine the stress field inside the films and provided a good fit to the experimental data. A comprehensive experimental and theoretical study of 3C-SiC MEMS structures has been performed and is presented.

scholarly journals High temperatures during microsporogenesis fatally shorten pollen lifespan

2021 ◽  
Author(s):  
Maurizio Iovane ◽  
Giovanna Aronne
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Heat Stress ◽  
High Temperature ◽  
Male Gametophyte ◽  
Crop Productivity ◽  
Anther Dehiscence ◽  
Optimal Temperature ◽  
Drastic Reduction ◽  
Crop Species

AbstractMany crop species are cultivated to produce seeds and/or fruits and therefore need reproductive success to occur. Previous studies proved that high temperature on mature pollen at anther dehiscence reduce viability and germinability therefore decreasing crop productivity. We hypothesized that high temperature might affect pollen functionality even if the heat treatment is exerted only during the microsporogenesis. Experimental data on Solanum lycopersicum ‘Micro-Tom’ confirmed our hypothesis. Microsporogenesis successfully occurred at both high (30 °C) and optimal (22 °C) temperature. After the anthesis, viability and germinability of the pollen developed at optimal temperature gradually decreased and the reduction was slightly higher when pollen was incubated at 30 °C. Conversely, temperature effect was eagerly enhanced in pollen developed at high temperature. In this case, a drastic reduction of viability and a drop-off to zero of germinability occurred not only when pollen was incubated at 30 °C but also at 22 °C. Further ontogenetic analyses disclosed that high temperature significantly speeded-up the microsporogenesis and the early microgametogenesis (from vacuolated stage to bi-cellular pollen); therefore, gametophytes result already senescent at flower anthesis. Our work contributes to unravel the effects of heat stress on pollen revealing that high temperature conditions during microsporogenesis prime a fatal shortening of the male gametophyte lifespan.

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