scholarly journals Primary Standard for the High-Pressure Scale and Shock-Compressed State of Matter.

2002 ◽  
Vol 12 (4) ◽  
pp. 345-348 ◽  
Author(s):  
Ken-ichi KONDO
Keyword(s):  
High Pressure ◽  
Primary Standard ◽  
Pressure Scale ◽  
State Of Matter

XII.—On the Theory of Unimolecular Gas Reactions: A Quantum Harmonic Oscillator Model

1954 ◽  
Vol 64 (2) ◽  
pp. 161-174 ◽  
Author(s):  
N. B. Slater
Keyword(s):  
High Pressure ◽  
Classical Mechanics ◽  
Classical Case ◽  
Constant Factor ◽  
Quantum Case ◽  
Fundamental Vibration ◽  
Fixed Temperature ◽  
Dissociation Probability ◽  
Pressure Scale ◽  
Continuum Of States

SynopsisThe writer's theory of unimolecular dissociation rates, based on the treatment of the molecule as a harmonically vibrating system, is put in a form which covers quantum as well as classical mechanics. The classical rate formulæ are as before, and are also the high-temperature limits of the new quantum formulæ. The high-pressure first-order rate k∞ is found first from the Gaussian distribution of co-ordinates and momenta of harmonic systems, and is justified for the quantum-mechanical case by Bartlett and Moyal's phase-space distributions. This leads to a re-formulation of k∞ as a molecular dissociation probability averaged over a continuum of states, and to a general rate for any pressure of the gas.The high-pressure rate k∞ is of the form ve-F/kT, where v and F depend, in the quantum case, on the temperature T; but v is always between the highest and lowest fundamental vibration frequencies of the molecule. Concerning the decline of the general rate k with pressure at fixed temperature, k/k∞ is to a certain approximation the same function of as was tabulated earlier for the classical case, apart from a constant factor changing the pressure scale in the quantum case.

Correction to the High-Pressure Scale

Nature ◽  
1962 ◽  
Vol 196 (4850) ◽  
pp. 159-160 ◽  
Author(s):  
ALFRED BOBROWSKY
Keyword(s):  
High Pressure ◽  
Pressure Scale

scholarly journals Measurement Standards of Ukraine for Gas Volume Flow Rate at Pressures of 1 MPa to 5 MPa

2021 ◽  
Vol 2 ◽  
Author(s):  
Mykhailo Rozhnov ◽  
Dmytro Melnyk ◽  
Ovsiy Levbarg
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Primary Standard ◽  
Metrological Traceability ◽  
Gas Flow Rate ◽  
Flow Measurements ◽  
Working Standard ◽  
Measurement Standards ◽  
Primary Measurement

The characteristics of the primary measurement standards of the volume gas flow rate at high pressure developed in various countries are considered. A hierarchical scheme for gas flow measuring instruments and a corresponding metrological traceability chain are presented. Described is a PVTt method, on which the primary standards of gas flow rate used in the USA, France, Japan, and Taiwan are based. The need to create in Ukraine primary measurement standards of gas flow rate at high pressure covering different parts of the total flow rate interval from 0,3 m3/h to 1800 m3/h at a pressure of 1 MPa to 5 MPa is substantiated. Metrological traceability of gas flow measurements is realized through a sequence of critical flow Venturi nozzles, which play a role of the reference flow rate material measures. The standards might be used to calibrate the primary reference Venturi nozzles of the most common 0,1 mm to 8 mm diameters. The characteristics and parameters of the standards are determined. By their metrological and technical characteristics, the standards will correspond to the state-of-the-art level. According to the programme of developing the measurement-standard facilities in Ukraine, in 2019 the primary standard PVTt-65 was created and work had started on the development of the primary standard PVTt-1800 and the working standard PE-5400. A detailed study of the metrological characteristics of the measurement standards will be the topic of further work.

A High Pressure Differential Manometer

1963 ◽  
Vol 85 (2) ◽  
pp. 180-181 ◽  
Author(s):  
S. C. Barnett ◽  
T. W. Jackson ◽  
R. H. Whitsides
Keyword(s):  
High Pressure ◽  
Primary Standard ◽  
Pressure Differential ◽  
Differential Manometer ◽  
Pressure Drops ◽  
Mercury Surface

A unique manometer has been designed and successfully used to measure pressure drops of a few millimeters of mercury at static pressures up to 10,000 psia. The manometer, which utilizes a column of water and mercury, is a primary standard because the mercury surface is visible at all times. It is designed for static pressures up to 20,000 psi; however, very minor revisions would make the manometer suitable for pressures up to 50,000 psi. A description of the manometer and pertinent equations is included.

Diamond and cubic boron nitride under high pressure: Raman scattering, equation of state and high pressure scale

1989 ◽  
Vol 1 (5-6) ◽  
pp. 333-336 ◽  
Author(s):  
I. V. Aleksandrov ◽  
A. P. Goncharov ◽  
I. N. Makarenko ◽  
A. N. Zisman ◽  
E. V. Jakovenko ◽  
...  
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Boron Nitride ◽  
Raman Scattering ◽  
Cubic Boron Nitride ◽  
Pressure Scale
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