Methodology for Measurement of Density of Liquid Oxides

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Jan Hrbek ◽  
Bence Mészáros ◽  
Mykhaylo Paukov ◽  
Martin Kudláč
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Extreme Conditions ◽  
Nuclear Accidents ◽  
System A ◽  
Different Temperatures ◽  
Density Values ◽  
Properties Of Materials ◽  
The Difference

Abstract Measurement of physical properties of materials in extreme conditions, such as high temperature, is limited by technological challenges. Nevertheless, modeling of several phenomena relies on the existence of experimental data for their validation. In this study, a method suitable for determination of density in a liquid phase at high temperature is proposed and tested on Al2O3–ZrO2 system. A methodology for acquiring the temperature dependence of density for radioactive materials is proposed and is aimed to refine severe nuclear accidents modeling. The oxide was melted in an induction furnace with a cold crucible. The measurement was based on evaluation of the volume of the melt at different temperatures, in a range from 2100 to 2400 °C. The densities of the oxide in the solid-state and the skull-layer were measured using a pycnometer. A temperature dependence of the density was established and the results were compared with literature. The difference between existing data and the measured values in this work was less than 5%. Thus, the proposed methodology provides reliable density values in extreme conditions.

Pyridine Extraction Method for Determination of Bacitracin in Feeds: Collaborative Evaluation

1979 ◽  
Vol 62 (3) ◽  
pp. 662-670
Author(s):  
Hussein S Ragheb
Keyword(s):  
High Temperature ◽  
Extraction Method ◽  
Main Difficulty ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
The Difference ◽  
Zinc Bacitracin ◽  
Collaborative Evaluation

Abstract Seventeen laboratories evaluated the pyridine extraction method and neomycin-sensitized agar for the determination of zinc and MD bacitracin in swine and broiler rations at 10 and 100 g/ton. The method was also applied to the analysis of 2 premixes labeled 50 g/lb (MD bacitracin) and 40 g/lb (zinc bacitracin). Bacitracin activity was determined on each of 2 days with 2 dilutions on each day. No significant difference was found between dilutions within a day or between days for each sample. The type of bacitracin or type of feed did not significantly affect results. The difference in results between MD and zinc bacitracin in premixes approached significance. The large coefficients of variation for premixes (ca 13%) and complete feeds (ca 15–30%) indicate operational problems. The main difficulty was evaporation of pyridine. Some laboratories were not able to evaporate it completely, whereas others lost bacitracin activity, probably due to high temperature of drying. The pyridine extraction method as in 42.200 and 42.204 should be discontinued.

Evaluation of Low-Temperature Properties and the Fragility of Asphalt Binders with Non-Arrhenius Viscosity–Temperature Dependence

2005 ◽  
Vol 1901 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Huachun Zhai ◽  
Delmar Salomon
Keyword(s):  
Temperature Dependence ◽  
Asphalt Binders ◽  
Arrhenius Behavior ◽  
Direct Tension ◽  
Different Temperatures ◽  
Rotational Viscosity ◽  
Liquid Fragility ◽  
The Difference ◽  
Critical Cracking Temperature ◽  
Experimental Values

Rotational viscosities of different asphalt binders were determined at temperatures between 80°C and 185°C. Viscosity–temperature dependence of asphalt binders was described with the use of the Vogel–Tammann–Fulcher (VTF) and the William–Landel–Ferry (WLF) equations. The Vogel temperature ( Tv) and the glass transition temperature ( Tg) for different asphalt binders were determined by fitting experimental values of viscosity at different temperatures with these two equations. For asphalt binders, the difference between Tv and Tg was about 40K. Effects of asphaltenes, aging, chemical modification, and polymer content on these temperatures were evaluated. As asphaltene content increased, both temperatures, Tv and Tg, increased. Different polymers showed different effects on these temperatures. The values of Tv and Tg were correlated with the critical cracking temperature ( Tcr) determined through use of a bending beam rheometer and a direct tension tester. The results suggested that the correlations between Tv, Tg, and Tcr could be used to determine Tcr from the rotational viscosity results tested at high temperature. With simple rotational measurements, a quick estimation of Tcr of asphalt binders could be obtained. Liquid fragility theory was also used to study Tg of asphalt binders. Parameters determined with the VTF and WLF equations indicated that asphalt binders behaved as fragile liquids because of their non-Arrhenius behavior in the temperature range studied.

scholarly journals XXVII. On the expansion by heat of metals and alloys

1866 ◽  
Vol 156 ◽  
pp. 861-881 ◽  
Keyword(s):  
Linear Expansion ◽  
Metals And Alloys ◽  
Different Temperatures ◽  
The Difference

In a memoir “On the Expansion by Heat of Water and Mercury”*, I described a method of determining the expansion of bodies by weighing them in water at different temperatures. This method was chosen on account of its yielding accurate results with comparatively small quantities, for to purify large quantities of metal would entail immense labour and expense; so much so, in fact, that to purify sufficient quantities to make bars for the determination of the linear expansion would be practically impossible. On determining the expansion of the metals by this method, I found that they did not expand regularly between 0° and 100°. The difference, however, between the rates of expansion between 0° and 50° and 50° and 100° was found to be so great that part of it might be possibly attributed to errors in the determination of the coefficients of expansion of water, as the coefficients of expansion of the metals are comparatively small when compared with those of water. Now, although the coefficient of expansion of mercury when determined by this method agrees with Regnault's value, yet on account of this value being large, small errors in the water coefficients will not materially influence it ; for the volume of water at 4°=1·0000, at 100°=1·04316, that of mercury at 0°=l·0000, at 100°=1·01815, and that of copper, for instance, at 0°=1·00000, at 100°=1004998, showing that the expansion of copper is very small compared with that of water or mercury.

Mechanical Properties Analysis of Super Early-Strength Composite Fiber Concrete after High Temperature

2014 ◽  
Vol 584-586 ◽  
pp. 1351-1354
Author(s):  
Chang Zheng Sun ◽  
Rui Xiao Wu ◽  
Hai Nan Zhao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Concrete Specimen ◽  
Composite Fiber ◽  
High Temperature Mechanical Properties ◽  
Fiber Concrete ◽  
Different Temperatures ◽  
Axial Compressive Strength ◽  
Properties Of Materials ◽  
Early Strength

Experimental method is applied to analysis the mechanical properties of super early-strength composite fiber concrete on high temperature. Specimen are heated to in the stove at different temperatures for 30 Minutes, then the axial compressive strength can be measured. The experimental results showed that: the high temperature mechanical properties of materials decreased significantly; compared to ordinary concrete specimen, the mechanical properties of super early-strength composite fiber concrete decline slower.

Revised Penetration Method Based on Evaluate High Temperature Property of SBS Modified Asphalt

2017 ◽  
Vol 902 ◽  
pp. 3-8
Author(s):  
Sen Han ◽  
Pei Sun ◽  
Ya Min Liu ◽  
Wei Li
Keyword(s):  
High Temperature ◽  
Asphalt Mixture ◽  
Temperature Property ◽  
Modified Asphalt ◽  
Specification Method ◽  
Different Temperatures ◽  
High Temperature Property ◽  
The Difference ◽  
Sbs Modified Asphalt ◽  
Temperature Susceptibility

In order to achieve the penetration method which could reflect the high temperature property of SBS modified asphalt, the paper presented the penetration test of SBS modified asphalt with different types and dosages of SBS modifier at three kinds of penetration weight and four different temperatures. Meanwhile, the high temperature performance of the SBS modified asphalt mixture was studied. It was found that penetration measured under current specification method (25oC, 100g, 5s) could not identify the difference of viscosity and high temperature property of different SBS modified asphalt. When the test conditions are revised to “penetration weight of 150 g, test temperature of 30oC, penetration time of 5s”, the penetration of different SBS modified asphalt measured by revised method could be used to evaluate the temperature susceptibility of SBS modified asphalt accurately and are closely related to the dynamic stability of mixture.

A New Method to Obtain U(J) Relationship in High Temperature Superconductor

1997 ◽  
Vol 11 (06) ◽  
pp. 753-765 ◽  
Author(s):  
M. J. Qin ◽  
X. Jin ◽  
X. X. Yao ◽  
Y. X. Fu ◽  
X. S. Rong ◽  
...  
Keyword(s):  
High Temperature ◽  
Magnetic Relaxation ◽  
High Temperature Superconductor ◽  
High Temperature Superconductors ◽  
Usual Method ◽  
New Method ◽  
Relaxation Data ◽  
J Curve ◽  
Different Temperatures

An implicit expression for the time dependence of the current density J(t) is derived without the constant assumption of dU/dJ or <dU/dJ>, based on which a new method to extract U(J) relationship from magnetic relaxation data in high temperature superconductors is described. This method is applied to a melt textured growth YBa2Cu3O6+x sample and we obtain U(J)~ J-μ with μ=0.90 for H‖c, which is in accordance with that derived by the usual method suggested by Malery et al.(μ=0.87). Moreover, both methods give the same value of the constant C, which implies that the determination of C by the requirement of continuity of the U(J) curve at different temperatures is reliable. And the results U(J)~ J-μ by both methods are evidence for the collective pinning or the vortex glass theory.

Determination of the enthalpy of fusion of K3TaO2F4 and KTaF6

2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Ladislav Kosa ◽  
Iveta Macková ◽  
Zuzana Netriová
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Enthalpy Of Fusion ◽  
Fusion Temperature ◽  
Fusion Enthalpy

AbstractAreas of fusion and crystallization peaks of K3TaO2F4 and KTaF6 were measured using the DSC mode of a high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities, considering the temperature dependence of the calorimeter sensitivity, values of the fusion enthalpy of K3TaO2F4 at the fusion temperature of 1181 K of (43 ± 4) kJ mol−1 and of KTaF6 at the fusion temperature of 760 K of (8 ± 1) kJ mol−1 were determined.

scholarly journals Effect of Rare Earth Upon As-Cast Microstructure and High Temperature Performance of ZA40 Alloy

2014 ◽  
Vol 8 (1) ◽  
pp. 251-256
Author(s):  
Jiaming Ji ◽  
Guocui Meng ◽  
Yuanyong Lu ◽  
Honghong Shao ◽  
Dongqing Gu
Keyword(s):  
Wear Resistance ◽  
Rare Earth ◽  
High Temperature ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Silicon Phase ◽  
Different Temperatures ◽  
Properties Of Materials ◽  
Re Elements ◽  
Cast Microstructure

In testing comparison, this study is made on the modification effect of 0.05 wt.% La-rich rare earth (RE) upon as-cast microstructure, mechanical properties of materials at high temperatures (100, 150, 200°C) and wear resistance under different temperatures (100and 200°C) of ZA40 alloy containing Si. The addition of RE shows that it can not only effectively refine Al-rich and Cu-rich phase, but also reduce the amount of needle-like eutectic silicon, and then make the size of massive primary silicon phase smaller. Thus, there are the improvement of strength, ductility and wear resistance of materials at high temperature. The analyses are also conducted on the mechanism of underlying RE elements.

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