scholarly journals The Virial Effect—Applications for SF6 and CH4 Thermal Plasmas

2019 ◽  
Vol 9 (5) ◽  
pp. 929
Author(s):  
Andriniaina Harry Solo ◽  
Pierre Freton ◽  
Jean-Jacques Gonzalez
Keyword(s):  
High Pressure ◽  
Pressure Range ◽  
High Pressures ◽  
Local Thermodynamic Equilibrium ◽  
Good Alternative ◽  
Mass Action ◽  
Lennard Jones ◽  
Engineering Data ◽  
Large Pressure ◽  
Mass Action Law

A tool based on the mass action law was developed to calculate plasma compositions and thermodynamic properties for pure gases and mixtures, assuming a local thermodynamic equilibrium for pressures of up to 300 bar. The collection of the data that was necessary for tool calculation was automated by another tool that was written using Python, and the formats for the model were adapted directly from the NIST and JANAF websites. In order to calculate the plasma compositions for high pressures, virial correction was introduced. The influences of the parameters that were chosen to calculate the Lennard–Jones (12-6) potential were studied. The results at high pressure show the importance of virial correction for low temperatures and the dependence of the dataset used. Experimental data are necessary to determine a good dataset, and to obtain interaction potential. However, the data available in the literature were not always provided, so they are not well-adapted to a large pressure range. Due to this lack, the formulation provided by L. I. Stiel and G. Thodos (Journal of Chemical and Engineering Data, vol. 7, 1962, p. 234–236) is a good alternative when the considered pressure is not close to the critical point. The results may depend strongly on the system studied: examples using SF6 and CH4 plasma compositions are given at high pressure.

C60 Transformations at High Pressures

1992 ◽  
Vol 270 ◽  
Author(s):  
C. S. Yoo ◽  
W. J. Nellis ◽  
M. L. Sattler ◽  
R. G. Musket ◽  
N. Hinsey ◽  
...  
Keyword(s):  
Thin Films ◽  
High Pressure ◽  
Pressure Range ◽  
High Pressures ◽  
Amorphous State ◽  
Ambient Conditions ◽  
Carbon Phase ◽  
Large Pressure ◽  
Diffraction Patterns ◽  
Intermolecular Distances

ABSTRACTC60 molecules have been studied at both shock and static high pressures. Under shock compressions C60 fullerenes are stable into the 13-17 GPa pressure range. The onset of a fast (∼0.5 μs) reconstructive transformation to graphite occurs near 17 GPa. The graphite recovered from 27 GPa and about 900 K is relatively well ordered with La = 100 Å. Above 50 GPa a continuous transformationto an amorphous state is observed in recovered specimens. A transparent, metastable carbon phase was recovered from thin films of C60, shocked to 69 GPa and 2200 K and then rapidly quenched to 1000 K. The selected area diffraction patterns indicate thatthe metastable carbon contains an amorphous diamond and n-diamond. Under hydrostatic compressions C60 molecules transform reversibly to a semi-transparent phase in the pressure range of 15-25 GPa with a large pressure hysteresis. The high pressure phaseconsists of interconnected strongly interacting C60 agglomerates, or networksof fullerenes, whose stability continuously increases with increase of pressure. Above 27 GPa the transition becomes irreversible, and the material recovered from high pressureis metastable and diamond-like at ambient conditions. These pressure-induced transitions are explained in terms of nr-electron rehybridization between C60 molecules, which occurs at substantially decreased intermolecular distances.

A Study for N2 Coherent Anti-Stokes Raman Spectroscopy Thermometry at High Pressure

1983 ◽  
Vol 37 (6) ◽  
pp. 508-512 ◽  
Author(s):  
Haruhiko Kataoka ◽  
Shiro Maeda ◽  
Chiaki Hirose ◽  
Koichi Kajiyama
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
High Temperature ◽  
Pressure Range ◽  
High Pressures ◽  
Band Width ◽  
Maximum Height ◽  
Temperature Determination ◽  
Engine Cylinder ◽  
Anti Stokes

N2 coherent anti-Stokes Raman spectroscopy (CARS) thermometry over a pressure range 1 to 50 atm has been studied. The CARS profile at high pressure and high temperature was recorded by using the ignition inside a running engine cylinder. The observed Q-branch profile was theoretically fitted by incorporating the collisional narrowing effect, serving for the temperature determination at various pressures. Because of the narrowing effect, the apparent band width showed little change with pressure above 5 atm in general. It has been suggested that the band width at 1/5 of the maximum height can be a useful measure of temperature, while the usual half-width turns out to be hardly practicable at high pressures.

X-ray diffraction study of HgBa2CuO4+δ at high pressures

1997 ◽  
Vol 12 (2) ◽  
pp. 106-112
Author(s):  
Eduardo J. Gonzalez ◽  
Winnie Wong-Ng ◽  
Gasper J. Piermarini ◽  
Christian Wolters ◽  
Justin Schwartz
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Pressure Range ◽  
High Pressures ◽  
Anisotropy Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anisotropic Elastic ◽  
High Pressure Study

An in situ high pressure study using energy dispersive X-ray diffraction has been carried out on the polycrystalline high-Tc superconductor, HgBa2CuO4+δ (Hg-1201), to study its phase stability under pressure and also to measure its compressibility and bulk modulus. No evidence of pressure-induced polymorphism was found in the pressure range investigated, i.e., from 0.1 MPa (1 atm) to 5 GPa. The compound exhibited anisotropic elastic properties. The axial compressibility along the c axis was measured to be (3.96±0.35)×10−3GPa−1 and along the a axis (3.42±0.13)×10−3GPa−1, corresponding to an anisotropy ratio of 1.16±0.11. The bulk modulus was determined to be (94.7±4.2) GPa and, assuming a Poisson's ratio of 0.2, Young's modulus was estimated to be (170±8) GPa.

Seismic parameter φ: Computation at very high pressure from laboratory data

1966 ◽  
Vol 56 (3) ◽  
pp. 725-731
Author(s):  
Orson L. Anderson
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Ultrasonic Velocity ◽  
Pressure Range ◽  
High Pressures ◽  
Equations Of State ◽  
Laboratory Data ◽  
Second Derivative ◽  
Velocity Measurements ◽  
Very High

abstract By using the accuracy inherent in ultrasonic velocity measurements taken at pressures less than 10 kb, the seismic parameter φ=vp2−(43)vS2 can be computed at very high pressures. The equation used requires the assumption that the second derivative with respect to pressure of the bulk modulus be negligible at all pressures considered. This assumption is checked by computing the compression (V/V0) in the pressure range by equations of state using the assumption, and comparing the resulting values with measured compression. Illustrations are given for MgO and Al2O3.

Viscoelastic properties of liquid pentachlorobiphenyl under pressure using depolarized light scattering

1983 ◽  
Vol 61 (9) ◽  
pp. 1291-1296 ◽  
Author(s):  
P. Bezot ◽  
C. Hesse-Bezot ◽  
Ph. Pruzan
Keyword(s):  
High Pressure ◽  
Light Scattering ◽  
Shear Modulus ◽  
Viscoelastic Properties ◽  
Pressure Range ◽  
Glassy State ◽  
Molecular Liquids ◽  
Large Pressure ◽  
Scattering Spectra ◽  
Depolarized Light Scattering

A study of the depolarized light scattering spectra of high pressure supercooled pentachlorobiphenyl is presented. From the analysis of the propagative shear doublet, the infinite shear modulus Gx is measured over a large pressure range, at various temperatures, up to a pressure where the liquid is in a glassy state. Gx(P) is found to vary linearly at each temperature. From values of Gx (P = 0.1 MPa) together with those obtained in a previous paper at P = 0.1 MPa as a function of T, it is concluded that Gx(T) is linear over 70 °C, contrary to what is generally obtained in most of the supercooled molecular liquids.

Tilting of semi-rigid GaF6 octahedra in GaF3 at high pressures

2017 ◽  
Vol 32 (S1) ◽  
pp. S69-S73
Author(s):  
Jens-Erik Jørgensen ◽  
Yaroslav Filinchuk ◽  
Vladimir Dmitriev
Keyword(s):  
High Pressure ◽  
Pressure Range ◽  
High Pressures ◽  
Sphere Packing ◽  
Volume Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compression Mechanism ◽  
Measured Pressure ◽  
Linear Compressibility

The VF3-type compound GaF3 has been studied by high-pressure angle-dispersive X-ray diffraction in the pressure range from 0.0001 to 10 GPa. The compression mechanism was found to be highly anisotropic. The c-axis shows little pressure dependence (≈0.4%), but exhibits negative linear compressibility up to ≈3 GPa where it achieves its maximum length. In contrast, the length of the a-axis is reduced by ≈8.8% at the highest measured pressure and an anomalous reduction in the linear compressibility is observed at 4 GPa. The zero pressure bulk modulus B0 was determined to B0 = 28(1) GPa. The compression mechanism of GaF3 is discussed in terms of deformation of an 8/3/c2 sphere-packing model. The volume reduction of GaF3 is mainly achieved through coupled rotations of the GaF6 octahedra within the entire measured pressure range, which reduces the volume of the cubooctahedral voids. In addition, the volume of the GaF6 octahedra also decreases for p ≲ 4.0 GPa, but remains constant above this pressure. The volume reduction of the GaF6 octahedra is accompanied by an increasing octahedral strain. Isosurfaces of the procrystal electron density are used for visualization of the cubooctahedral voids at different pressures.

scholarly journals Stochiometry Air − CH4 Mixture: Composition, Thermodynamic Propertiess and Transport Coefficients

2020 ◽  
Vol 7 (1) ◽  
pp. 21-29
Author(s):  
A. Harry Solo ◽  
M. Benmouffok ◽  
P. Freton ◽  
J.-J. Gonzalez
Keyword(s):  
Chemical Composition ◽  
Local Thermodynamic Equilibrium ◽  
Mass Density ◽  
Transport Coefficients ◽  
Equation System ◽  
Mass Action ◽  
Particle Interactions ◽  
First Order ◽  
Mass Action Law

This work is related to the determination of the local thermodynamic equilibrium (LTE) data of 90.5% air and 9.5% CH4 mixture. The results of chemical composition, thermodynamic properties and transport coefficients are presented for temperatures (300 K to 30 kK) and pressure (1 and 10 bars) or mass density (0.1481 and 1.111 kg.m<sup>−3</sup>). The chemical composition is determined using the mass action law. Input data come from the NIST and JANAF sites. For pressure equation, Debye-Huckel’s first order and virial’s second order corrections are used in the equation system to take into account the different particle interactions. For the considered mixture (90.5% air and 9.5% CH4) the properties are compared to those of pure air.

scholarly journals Ternary superconducting cophosphorus hydrides stabilized via lithium

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Ziji Shao ◽  
Defang Duan ◽  
Yanbin Ma ◽  
Hongyu Yu ◽  
Hao Song ◽  
...  
Keyword(s):  
High Pressure ◽  
First Principles ◽  
Structure Prediction ◽  
Pressure Range ◽  
High Temperature Superconductor ◽  
High Pressures ◽  
Experimental Studies ◽  
First Principles Calculations ◽  
Ternary Compounds ◽  
Stable Structures

Abstract Inspired by the diverse properties of sulfur hydrides and phosphorus hydrides, we combine first-principles calculations with structure prediction to search for stable structures of Li−P−H ternary compounds at high pressures with the aim of finding novel superconductors. It is found that phosphorus hydrides can be stabilized under pressure via additional doped lithium. Four stable stoichiometries LiPH3, LiPH4, LiPH6, and LiPH7 are uncovered in the pressure range of 100–300 GPa. Notably, we find an atomic LiPH6 with $$Pm\overline 3$$ P m 3 ¯ symmetry which is predicted to be a potential high-temperature superconductor with a Tc value of 150–167 K at 200 GPa and the Tc decreases upon compression. All the predicted stable ternary hydrides contain the P–H covalent frameworks with ionic lithium staying beside, but not for $$Pm\overline 3$$ P m 3 ¯ -LiPH6. We proposed a possible synthesis route for ternary lithium phosphorus hydrides: LiP + H2 → LiPHn, which could provide helpful and clear guidance to further experimental studies. Our work may provide some advice on further investigations on ternary superconductive hydrides at high pressure.

An absolute high-pressure microviscometer based on refractive index

1972 ◽  
Vol 331 (1585) ◽  
pp. 171-184 ◽  
Keyword(s):  
High Pressure ◽  
Refractive Index ◽  
Optical Constants ◽  
High Pressures ◽  
Point Contact ◽  
Viscosity Coefficient ◽  
Pressure Gradients ◽  
Viscosity Measurements ◽  
Large Pressure ◽  
Very High

A now method of measuring refractive index in a lubricant point contact is described which allows the density, pressure and viscosity in the fluid to be determined. The viscosity measurements are absolute, only the elastic and optical constants of the glass are needed. Due to the very high pressures developed (1 GPa) in the 0.3 mm diameter contact very large pressure gradients are produced, hence viscosities four orders higher than conventional high-pressure viscometers normally reach, can be measured. Four lubricants tested all showed that the pressure viscosity coefficient dropped sharply above 10 3 Pa s (10 4 poise); the limit of the normal viscometer. One fluid - a polyphenylether - apparently vitrified at high pressures to a limiting viscosity of 10 6 Pa s. Ball bounce is shown to limit the range of fluids that can be tested with this apparatus.

Studies on Activator Formation in Human Plasma with Streptokinase

1973 ◽  
Vol 30 (02) ◽  
pp. 381-392
Author(s):  
M Martin ◽  
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Mass Action ◽  
Activator Concentration ◽  
Kinetic Effect ◽  
Mass Action Law

SummaryThe plasminogen-streptokinase complex called “activator” was present in diluted plasma in the form of a largely dissociated mixture. More than ⅞ of the streptokinase and plasminogen molecules were available for further activator formation.The activator is probably a dissociated complex of the formulaStreptokinase + Plasminogen ⇄ Activator.The fact that an increase in activator concentration by x times is obtained by multiplying either the streptokinase content by the factor y or the plasminogen concentration by the same factor y would point to a kinetic effect along the lines of the mass action law.

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