Enthalpy of vaporization, its temperature dependence and correlation with surface tension: A theoretical approach

2017 ◽  
Vol 432 ◽  
pp. 62-69 ◽  
Author(s):  
Amin Alibakhshi
Keyword(s):  
Surface Tension ◽  
Temperature Dependence ◽  
Theoretical Approach ◽  
Enthalpy Of Vaporization

scholarly journals Surface Tension and Density of Liquid Hot Work Tool Steel W360 by voestalpine BÖHLER Edelstahl GmbH & Co KG Measured with an Electromagnetic Levitation Apparatus

2020 ◽  
Vol 42 (2) ◽  
Author(s):  
Thomas Leitner ◽  
Anna Werkovits ◽  
Siegfried Kleber ◽  
Gernot Pottlacher
Keyword(s):  
Surface Tension ◽  
Temperature Dependence ◽  
Linear Model ◽  
Tool Steel ◽  
Pure Iron ◽  
Electromagnetic Levitation ◽  
Liquid Density ◽  
Hot Work Tool Steel ◽  
Significant Difference ◽  
Main Component

AbstractW360 is a hot work tool steel produced by voestalpine BÖHLER Edelstahl GmbH & Co KG, a special steel producer located in Styria, Austria. Surface tension and density of liquid W360 were studied as a function of temperature in a non-contact, containerless fashion using the oscillating drop method inside an electromagnetic levitation setup. For both, surface tension and density, a linear model was adapted to present the temperature dependence of these measures, including values for the uncertainties of the fit parameters found. The data obtained are compared to pure iron (with 91 wt% the main component of W360), showing an overlap for the liquid density while there is a significant difference in surface tension (− 5.8 % at the melting temperature of pure iron of 1811 K).

Many Band Effects in Cuprate Superconductors

1997 ◽  
Vol 11 (13) ◽  
pp. 585-592
Author(s):  
S. P. Kruchinin ◽  
A. M. Yaremko ◽  
E. V. Mozdor
Keyword(s):  
Experimental Data ◽  
Fermi Level ◽  
Temperature Dependence ◽  
Theoretical Approach ◽  
Cuprate Superconductors ◽  
Electron Pair ◽  
Recent Experimental Data ◽  
Natural Manner ◽  
System A ◽  
Interacting Electrons

The new theoretical approach is proposed for study the states responsible for superconductivity of crystals. Within the frameworks of worked out approach it is shown that in electron–phonon system a class of new so-called coupled states arises. Postulated in BCS method electron-pair states k1 + k2 = 0, s + s′ = 0 are in natural manner included in this class. The model numerical calculations have shown that SC gap depends on number of bands crossing the Fermi level on the momenta k1+k2 = K≠ 0 of interacting electrons and that the temperature dependence of SC gap for HTSC is more complicated (in agreement with the recent experimental data) then predicted in BCS approach.

Correlations and Theory for Microchannel Condensation

2008 ◽  
Author(s):  
Qian Su ◽  
Guang Xu Yu ◽  
Hua Sheng Wang ◽  
John W. Rose
Keyword(s):  
Heat Transfer ◽  
Surface Tension ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Theoretical Approach ◽  
Annular Flow ◽  
Fair Agreement ◽  
Calculation Methods ◽  
Fluid Property ◽  
The Heat Transfer Coefficient

In recent years several correlations have been proposed for calculating the heat-transfer coefficient during condensation in circular and non-circular channels of typical dimension around 1 mm where surface tension effects are important and correlations for larger diameter channels are inappropriate. A wholly theoretical approach applicable to annular flow has also been proposed. The correlations are all based on data for R134a, while the theory is applicable to any fluid. In this paper comparisons are made between the correlations for R134a and ammonia; plots based on theory are also included. Fair agreement is seen between all calculation methods for R134a but wide differences are seen for ammonia indicating that the correlations, based only on one fluid, do not capture the fluid property dependence accurately.

Density and Surface Tension of Fe-Cu Melts

2020 ◽  
Vol 992 ◽  
pp. 545-550
Author(s):  
Vladimir V. Vyukhin ◽  
O.A. Chikova ◽  
Ksenya Yu. Shmakova
Keyword(s):  
Surface Tension ◽  
Temperature Dependence ◽  
Cast Steel ◽  
Liquid Alloys ◽  
Humid Atmosphere ◽  
Damping Characteristics ◽  
Metal Melts ◽  
Cu Alloys ◽  
Two Phases ◽  
Large Machine

Fe-Cu alloys are used as structural materials for manufacture of large machine parts subjected to shock loads. Fe-Cu alloys have a higher corrosion resistance in a humid atmosphere and in salt solutions than cast steel. Fe-Cu alloys have high enough damping characteristics. Upon cooling the Fe-Cu melts is stratified into two phases before crystallization which in field of gravity are separated by density. It is possible to suppress delamination and obtain a material with structure of a “frozen emulsion” by heating melt to the temperature T* determined for each composition by a specific way. In this paper, we studied surface tension of liquid alloys of Fe-1wt.% Cu, Fe-20wt.% Cu, and Fe-30wt.%Cu in order to determine the temperature T*. For the melt of Fe-20wt.% Cu value T*=1670°C is highest. It is confirmed by results of measuring temperature dependence of surface tension. Temperature dependence of the surface tension Fe-Cu melts is characterized by a positive value of the temperature coefficient of surface tension dσ/dT which is abnormal for metal melts. Experimental data on the density, the surface tension of Fe-Cu liquid alloys have of independent metrological importance for practical foundry.

The correlations of the enthalpy of vaporization and the surface tension of molecular liquids

2006 ◽  
Vol 250 (1-2) ◽  
pp. 125-130 ◽  
Author(s):  
Aliaksei A. Strechan ◽  
Gennady J. Kabo ◽  
Yauheni U. Paulechka
Keyword(s):  
Surface Tension ◽  
Enthalpy Of Vaporization ◽  
Molecular Liquids
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