Self‐Consistent Ultrasonic Method for the Determination of the Equation of State of Liquids at Very High Pressures

1969 ◽  
Vol 40 (4) ◽  
pp. 1609-1613 ◽  
Author(s):  
Peter L. M. Heydemann ◽  
James C. Houck
Keyword(s):  
Equation Of State ◽  
High Pressures ◽  
Ultrasonic Method ◽  
Self Consistent ◽  
Very High

Method for the Experimental Determination of the Bunsen Absorption Coefficient of Hydraulic Fluids

2019 ◽  
Author(s):  
Andris Rambaks ◽  
Katharina Schmitz
Keyword(s):  
Equation Of State ◽  
Absorption Coefficient ◽  
Error Estimate ◽  
High Pressures ◽  
Volumetric Method ◽  
Virial Equation ◽  
Amount Of Substance ◽  
Virial Equation Of State ◽  
Hydraulic Fluids

Abstract A manometric-volumetric method to determine the Bunsen absorption coefficient of hydraulic fluids at high-pressures is presented. The virial equation of state is used to determine the amount of substance and its composition in the gaseous phase and at high-pressures. An error-analysis is presented for a best-case error estimate of the method.

scholarly journals Thermoelastic properties of magnesiowüstite, (Mg1−xFex)O: determination of the Anderson–Grüneisen parameter by time-of-flight neutron powder diffraction at simultaneous high pressures and temperatures

2008 ◽  
Vol 41 (5) ◽  
pp. 886-896 ◽  
Author(s):  
Ian G. Wood ◽  
Lidunka Vočadlo ◽  
David P. Dobson ◽  
G. David Price ◽  
A. D. Fortes ◽  
...  
Keyword(s):  
Equation Of State ◽  
Powder Diffraction ◽  
High Pressures ◽  
Equations Of State ◽  
Time Of Flight ◽  
Neutron Powder Diffraction ◽  
Grüneisen Parameter ◽  
Gruneisen Parameter ◽  
Measured State

The ability to perform neutron diffraction studies at simultaneous high pressures and high temperatures is a relatively recent development. The suitability of this technique for determiningP–V–Tequations of state has been investigated by measuring the lattice parameters of Mg1−xFexO (x= 0.2, 0.3, 0.4), in the rangeP < 10.3 GPa and 300 <T< 986 K, by time-of-flight neutron powder diffraction. Pressures were determined using metallic Fe as a marker and temperatures were measured by neutron absorption resonance radiography. Within the resolution of the experiment, no evidence was found for any change in the temperature derivative of the isothermal incompressibility, ∂KT/∂T, with composition. By assuming that the equation-of-state parameters either varied linearly or were invariant with composition, the 60 measured state points were fitted simultaneously to aP–V–T–xequation of state, leading to values of ∂KT/∂T= −0.024 (9) GPa K−1and of the isothermal Anderson–Grüneisen parameter δT= 4.0 (16) at 300 K. Two designs of simultaneous high-P/Tcell were employed during this study. It appears that, by virtue of its extended pressure range, a design using toroidal gaskets is more suitable for equation-of-state studies than is the system described by Le Godec, Dove, Francis, Kohn, Marshall, Pawley, Price, Redfern, Rhodes, Ross, Schofield, Schooneveld, Syfosse, Tucker & Welch [Mineral. Mag.(2001),65, 737–748].

An experimental determination of the melting curves of argon and nitrogen into the 10000 atm region

1954 ◽  
Vol 225 (1162) ◽  
pp. 393-405 ◽  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Small Volume ◽  
High Pressures ◽  
Steel Tube ◽  
Melting Curves ◽  
New Apparatus ◽  
Very High ◽  
Small Steel

A new apparatus for measuring melting curves at low temperatures and very high pressures is described. It is essentially a combined cryostat and high-pressure intensifier connected by a single junction at room temperature. The pressure is produced in a number of stages culminating in a single intensification stroke on to a small volume of gas maintained at low temperatures in a long steel tube. Solidification and melting are detected in this tube by means of a small steel pellet, which may be moved by an external magnetiċ field when the substance is fluid. Experiments have been carried out on argon and nitrogen. The solid-fluid equilibrium line has been extended to 8250 atm at 234° K for argon, and to 9100 atm at 180° K for nitrogen.

On the collapse of an empty cavity in water

1960 ◽  
Vol 8 (2) ◽  
pp. 241-263 ◽  
Author(s):  
C. Hunter
Keyword(s):  
Equation Of State ◽  
Similarity Solution ◽  
High Pressures ◽  
Similarity Theory ◽  
Flow Equations ◽  
Regularity Properties ◽  
Flow Speeds ◽  
Empty Cavity ◽  
Subsequent Propagation ◽  
Very High

This paper is concerned with the spherically symmetric collapse of an empty cavity in water. The effects of viscosity and surface tension are neglected, but the compressibility of the water is allowed for and a suitable equation of state for the water assumed. The object of this is to clarify the effect of compressibility on the flow by considering it in isolation and thus to describe the formation of a pressure pulse by the collapse and its subsequent propagation.The exact flow equations are integrated numerically and it is found that very high flow speeds develop in the neighbourhood of the collapse point. The radius of the cavity is found to be proportional to (-t)nfor smallt, wheret= 0 is the instant of collapse, andnis some positive number less than unity.The flow in the neighbourhood of the collapse point can be described by means of a similarity solution, and the value ofnis determined by regularity properties of the similarity solution (the value ofndepends on the equation of state assumed for the water). The similarity theory, which is valid only at very high pressures and velocities, can be continued beyond the instant of collapse to describe the formation of a shock wave after the collapse is completed, and the initial propagation of this shock.

A Model of Strain Distribution in Nanocrystalline SiC and Diamond at Very High Pressures; In-Situ X-RAY Diffraction Study and Computer Modelling

1998 ◽  
Vol 538 ◽  
Author(s):  
R. Pielaszek ◽  
B. Palosz ◽  
S. Gierlotka ◽  
S. Stel'Makh ◽  
U. Bismayer
Keyword(s):  
High Pressures ◽  
Computer Modelling ◽  
Nanocrystalline Silicon ◽  
X Ray Diffraction ◽  
Nanocrystalline Silicon Carbide ◽  
Structure And Microstructure ◽  
Very High ◽  
Internal Strains

AbstractA modeling of nanoparticles and ab initio simulation of the scattered intensity from the Debye functions is used as a tool for an examination of the strain induced under high pressure in nanocrystalline silicon carbide and diamond. The analysis of the experimental intensity profiles includes a determination of the atomic structure and microstructure of the materials. The advantages of modeling over conventional methods of the analysis of powder diffraction data are discussed. Examples of using the modeling for determination of the shape and size and of one dimensional disordering in very small particles (2-4 nm), and development of internal strains in 10 nm SiC nanocrystals subjected to high pressures are given.

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