scholarly journals Analysis of Thermodynamic and Volume Expansion Properties of Nacl Solid at High Temperatures and Pressures

2020 ◽  
pp. 178-181
Author(s):  
S Singh ◽  
P. K. Singh ◽  
S. K. Pathak
Keyword(s):  
High Temperature ◽  
Elastic Property ◽  
Temperature Dependence ◽  
High Temperatures ◽  
Atmospheric Pressure ◽  
Volume Expansion ◽  
Close Agreement ◽  
Expansion Ratio ◽  
Effect Of Temperature ◽  
Thermal Pressure

In the present study, we derived new relationship and expression for temperature dependence of thermal pressure for NaCl crystal. A mostly elastic property of solid depends on the strength of inter atomic forces of solids. The present work approach has been developed on the temperature dependence of thermal pressure for NaCl crystal at atmospheric pressure and volume expansion ratio at high temperature. So far our work has been concerted on thermal pressure is dependent of temperature and diverges it’s linearly in high temperature volume expansion ratio through effect of temperature. A close data and Gruneisen parameter is found to be in close agreement with investigational and theoretical shows the standing of present study.

scholarly journals Study of Elastic Properties of Ionic Solids at High Temperature and Volume Expansion Ratio

2021 ◽  
pp. 232-236
Author(s):  
Sanjay Singh
Keyword(s):  
High Temperature ◽  
Elastic Property ◽  
Temperature Dependence ◽  
Atmospheric Pressure ◽  
Present Method ◽  
Volume Expansion ◽  
Expansion Ratio ◽  
Effect Of Temperature ◽  
Thermal Pressure ◽  
Ionic Solids

In our study we develop a new expression for temperature dependence of thermal pressure for MgO and CaO crystal. A generally elastic property of solid depends on the strength of inter atomic forces of solid. So far our work has been resolute on thermal pressure is dependent of temperature and diverges it’s linearly in high temperature volume expansion ratio through the effect of temperature. This present method has been developed on the temperature dependence of thermal pressure for MgO and CaO crystal at atmospheric pressure and volume expansion ratio at high temperature. A neighboring data of Gruneisen parameter is found to be in close convention with theoretical and investigational confirmations the standing of present study.

TEMPERATURE DEPENDENCE OF THERMODYNAMIC PROPERTIES OF IONIC SOLIDS

2009 ◽  
Vol 23 (11) ◽  
pp. 2503-2509 ◽  
Author(s):  
S. K. SHARMA
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Volume Expansion ◽  
Close Agreement ◽  
Present Model ◽  
Expansion Ratio ◽  
Thermal Expansivity ◽  
Temperature Derivative ◽  
Computing Model ◽  
Ionic Solids

The present paper proposes a computing model for temperature dependence of volume thermal expansivity, volume expansion ratio and second order temperature derivative of volume based on the assumption that the product αKT remains constant at high temperatures and zero pressure. We have taken NaCl and KCl to testify the validity of the present model. A fairly close agreement between the calculated results and experimental data strongly supports the present model.

Temperature Dependence and Martensitic Transformation of Ti50Pt50 Shape Memory Alloys

2014 ◽  
Vol 1019 ◽  
pp. 379-384
Author(s):  
M.P. Mashamaite ◽  
Hasani Rich Chauke ◽  
Rosinah Mahlangu ◽  
P.E. Ngoepe
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Temperature Dependence ◽  
Effect Of Temperature ◽  
Displacive Transformation ◽  
B2 Phase ◽  
Recent Experimental Work

Shape memory alloys (SMAs) are a fascinating group of metals that have two remarkable properties, the shape memory effect and superelasticity. The TiPt structure with the B2 phase has been reported to undergo a reversible displacive transformation to B19 martensite at about 1200K. However, this system could serve in principle as the basis of high-temperature shape memory alloys. Molecular dynamics study of martensitic transformation in platinum titanium alloys was performed to investigate the effect of temperature dependence on B2 and B19 structures at 50 at.%Pt. The NPT ensemble was used to determine the properties of these systems and we found good comparisons with recent experimental work. The temperature dependence of TiPt shows potential martensitic change when B19 is heated to extreme high temperatures of 273K up to 1573K.

scholarly journals The effect of temperature upon radioactive disintegration

1912 ◽  
Vol 86 (586) ◽  
pp. 240-253 ◽  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Systematic Investigation ◽  
Effect Of Temperature ◽  
Active Matter ◽  
Radium Emanation ◽  
Γ Rays ◽  
Method Of Measurement ◽  
Positive Effect

Within the last few years the influence of high temperature on the activity of radium emanation, of the active deposit, and of radium C has been examined in detail by several authors. The conclusions arrived at have been conflicting, some workers affirming a positive effect of tem­perature, others denying it. This lack of agreement is due, however, to a difference in the method of measurement of the active matter under investigation. Those workers who measured the activity by γ-rays are all agreed that temperature has no effect whatever, while those who measured by β-rays found always an effect of some kind, in many cases of considerable magnitude, and often, indeed, of a very surprising nature. While, however, the fact that there is a β-ray effect is admitted by all, there is still a lack of agreement between the results of the experiments of different workers, and even of different experiments of the same worker, which is hardly to be expected if the effects were due to a definite change in the properties of the disintegrating atoms at high temperatures. In view, therefore, of the uncertainty which has arisen on a point of such great theoretical importance, a systematic investigation was necessary to obtain definite results, whether positive or negative. This the author, at the request of prof. Rutherford, has carried out.

Effect of temperature and/or pressure on lactoperoxidase activity in bovine milk and acid whey

2001 ◽  
Vol 68 (4) ◽  
pp. 625-637 ◽  
Author(s):  
LINDA R. LUDIKHUYZE ◽  
WENDIE L. CLAEYS ◽  
MARC E. HENDRICKX
Keyword(s):  
High Temperature ◽  
Atmospheric Pressure ◽  
Thermal Inactivation ◽  
Bovine Milk ◽  
Antagonistic Effect ◽  
Effect Of Temperature ◽  
Pressure Treatment ◽  
First Order ◽  
First Order Kinetics ◽  
High Temperature Sensitivity

At atmospheric pressure, inactivation of lactoperoxidase (LPO) in milk and whey was studied in a temperature range of 69–73 °C and followed first order kinetics. Temperature dependence of the first order inactivation rate constants could be accurately described by the Arrhenius equation, with an activation energy of 635·3±70·7 kJ/mol for raw bovine milk and 736·9±40·9 kJ/mol for diluted whey, indicating a very high temperature sensitivity. On the other hand, LPO is very pressure resistant and not or only slightly affected by treatment at pressure up to 700 MPa combined with temperatures between 20 and 65 °C. Both for thermal and pressure treatment, stability of LPO was higher in milk than in diluted whey. Besides, a very pronounced antagonistic effect between high temperature and pressure was observed, i.e. at 73 °C, a temperature where thermal inactivation at atmospheric pressure occurs rapidly, application of pressure up to 700 MPa exerted a protective effect. At atmospheric pressure, LPO in diluted whey was optimally active at a temperature of about 50 °C. At all temperatures studied (20–60 °C), LPO remained active during pressure treatment up to 300 MPa, although the activity was significantly reduced at pressures higher than 100 MPa. The optimal temperature was found to shift to lower values (30–40 °C) with increasing pressure.

High-temperature phases in ternary Zr–O–N systems

1999 ◽  
Vol 14 (10) ◽  
pp. 3840-3842 ◽  
Author(s):  
Edward L. Dreizin ◽  
Vern K. Hoffmann ◽  
Edward P. Vicenzi
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Phase Equilibria ◽  
Elemental Composition ◽  
Gas Phase ◽  
Combustion Product ◽  
High Temperatures ◽  
Atmospheric Pressure ◽  
Combustion Products ◽  
Metal Combustion

Zirconium aerosol was ignited and burned in atmospheric pressure air in microgravity using a 2.2-s drop tower. Combustion products were collected and analyzed using electron microscopy. The elemental composition analyses indicated that combustion product compositions fell along two linear traces on a ternary Zr–O–N diagram. Currently, the equilibrium Zr–O–N phases are not characterized at temperatures above 2000 °C, typical of zirconium combustion in air, and it is suggested that the phases detected in zirconium combustion products can serve as a guide to further studies of the Zr–O–N system at high temperatures. It is also suggested that experimental metal combustion techniques can be adopted for studying high-temperature metal–gas phase equilibria.

scholarly journals Effect of Temperature, Light, and Storage Time on the Seed Germination of Pinus bungeana Zucc. ex Endl.: The Role of Seed-Covering Layers and Abscisic Acid Changes

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 300 ◽  
Author(s):  
Congcong Guo ◽  
Yongbao Shen ◽  
Fenghou Shi
Keyword(s):  
Abscisic Acid ◽  
High Temperature ◽  
Seed Germination ◽  
High Temperatures ◽  
Germination Percentage ◽  
Effect Of Temperature ◽  
Inhibition Mechanism ◽  
Radicle Protrusion ◽  
Pinus Bungeana ◽  
And Storage

Pinus bungeana Zucc. ex Endl. is an endemic conifer tree species in China with high ornamental value. In order to investigate favorable conditions for seed germination and explore the germination inhibition mechanism of this species at high temperatures, the effects of temperature, light, and storage on the mean germination time (MGT), speed of germination (SG), and total germination percentage (TGP) are evaluated here. Seeds that have either been kept still or entered into a state of dormancy at high temperature are assessed here by a recovery experiment. Furthermore, the contribution of covering layers on thermo-inhibition is analyzed here, including the way they work. This has been realized by the structural observation and via the determination of the abscisic acid (ABA) content. The results show that seeds germinate to a high percentage (approximately 90%) at temperatures of 15 or 20 °C, with or without light, whereas higher temperatures of 25 or 30 °C impeded radicle protrusion and resulted in the germination percentage decreasing sharply (within 5%). Inhibition at high temperatures was thoroughly reversed (bringing about approximately 80% germination) by placing the ungerminated seeds in favorable temperatures and incubating them for an additional 30 days. Dry cold storage did little to reduce the temperature request for germination. Embryo coverings, especially the nucellar membrane, and ABA levels both had a dominant role in seed germination regulation in response to temperature. Under favorable temperature conditions, the levels of ABA significantly decreased. Germination occurred when the levels dropped to a threshold of 15 ng/g (FW (Fresh Weight)). Incubation at a high temperature (25 °C) greatly increased ABA levels and caused the inhibition of radicle protrusion.

Influence of Contact Metallisation on the High Temperature Characteristics of High-κ Dielectrics

2013 ◽  
Vol 740-742 ◽  
pp. 837-840
Author(s):  
Benjamin J.D. Furnival ◽  
Sandip K. Roy ◽  
Nicolas G. Wright ◽  
Alton B. Horsfall
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
High Temperatures ◽  
Epitaxial Layer ◽  
Electrical Characteristics ◽  
Temperature Characteristics ◽  
High K ◽  
High K Dielectric ◽  
Increasing Temperature ◽  
Mis Capacitors

In this work SiC-based MIS capacitors have been fabricated with different contact/high-k dielectric combinations and the temperature dependence of the characteristics have been examined in an N2ambient at temperatures between 323K and 673K. The structures utilise either a Pt or Pd catalytic gate contact and a TiO2or HfO2high-k dielectric, all of which are grown on a thin SiO2layer, thermally grown on the Si face of a 4H SiC epitaxial layer. The MIS capacitors have been studied in an N2 ambient between 323K and 673K and observations show that VFBreduces with increasing temperature. The majority of this variation is caused a reduction in the Ditinfluencing the structures electrical characteristics, due to a shift in the semiconductors bulk potential, which is due to the lower VTHof SiC-based MOSFETs at high temperatures.

Sign in / Sign up

Export Citation Format

Share Document