Chemical rates in detonation reaction zones: Determination of temperature and pressure dependence

1982 ◽  
Vol 77 (11) ◽  
pp. 5860-5861
Author(s):  
John B. Bdzil ◽  
Ray Engelke
Keyword(s):  
Pressure Dependence ◽  
Reaction Zones ◽  
Temperature And Pressure ◽  
Detonation Reaction

The pressure dependence of the dehydration of gypsum to bassanite

1987 ◽  
Vol 51 (361) ◽  
pp. 453-457 ◽  
Author(s):  
J. D. C. McConnell ◽  
D. M. Astill ◽  
P. L. Hall
Keyword(s):  
Elevated Temperature ◽  
Experimental Determination ◽  
Volume Change ◽  
Pressure Dependence ◽  
Thermodynamic Data ◽  
Dehydration Reaction ◽  
Temperature And Pressure ◽  
The Stability ◽  
Very High

AbstractA new experimental determination of the stability relationships for the dehydration of gypsum to the hemihydrate mineral bassanite at elevated temperature and pressure is described. The experimental method used depends on the observation of very small changes in pressure on the onset of reaction due to the potential volume change in the reaction. The technique yields P-T data of very high precision for this dehydration reaction, and the method is likely to be of use for other reactions. The experimental P-T results have been compared with those calculated from existing thermodynamic data for this reaction.

scholarly journals Temperature Variation at Solid-Fluid Interface of Thin Film Lubricated Contact Problems

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 922
Author(s):  
Szabolcs Szávai ◽  
Sándor Kovács
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Pressure Dependence ◽  
Hydrodynamic Pressure ◽  
Contact Problems ◽  
Element Formulation ◽  
Temperature And Pressure ◽  
Non Linear System ◽  
Element Method

Many calculating methods have been already developed for solving contact problems of parts such as gears, cams, and followers under fluid film lubrication conditions considering the temperature and pressure dependence. Similarly, the determination of the elasto-hydrodynamic pressure distribution the processes taking place in the lubricant and the contacting bodies, as well as in their environment, have to be dealt with simultaneously for the determination of the temperature field. A system of equation for the modelling of thermo-elastohydrodynamic lubrication between two contacting bodies containing hydrodynamic, thermodynamic, and strength problems is a highly non-linear system which becomes even more so if the temperature and pressure dependence of the material properties are considered. To solve this system, scientists started to use the finite element formulation in the 1960s and it was found to be a promising and reliable method. Earlier, the lubrication analysts used only the h-version finite element method (h-FEM) till 1991, when the first usage of the p-version finite element method (p-FEM) was published in the literature. In order to reduce the problem, in case of point or line contact, the contact bodies can be handled as semi-infinite ones. Following this simplification that had been successfully applied for the gap size determination, a substructure model was defined using analytical solution of the moving heat source. Instead of an iterative way between the solid and fluid problem, in this paper we present an efficient solution when thermal model for lubricant and surfaces were coupled and solved by a direct numerical method in one step.

Cu NQR Studies of the Superconductors YBa2Cu3Ox and YBa2Cu4O8

1990 ◽  
Vol 45 (3-4) ◽  
pp. 393-400 ◽  
Author(s):  
D. Brinkmann
Keyword(s):  
Pressure Dependence ◽  
Oxygen Deficiency ◽  
Relaxation Times ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Temperature And Pressure ◽  
University Of Zurich ◽  
The University ◽  
Knight Shifts

Abstract The paper reviews some copper NQR studies in the superconductors YBa2Cu3Ox and YBa2Cu4O8 performed at the University of Zürich. The following topics are discussed: the temperature and pressure dependence of the NQR frequencies; relation between linewidths and oxygen deficiency; the determination of the electric field gradients (EFG) and Knight shifts at the copper sites; discussion of some calculations of the EFG tensors; measurements of the various relaxation times in all phases. The results obtained in both structures are compared; possible interpretations are discussed.

Determination of the temperature and pressure dependence of the reaction OH + C2H4from 200–400 K using experimental and master equation analyses

2006 ◽  
Vol 8 (48) ◽  
pp. 5633-5642 ◽  
Author(s):  
Patricia A. Cleary ◽  
Maria Teresa Baeza Romero ◽  
Mark A. Blitz ◽  
Dwayne E. Heard ◽  
Michael J. Pilling ◽  
...  
Keyword(s):  
Master Equation ◽  
Pressure Dependence ◽  
Temperature And Pressure

Measurements of real non-Newtonian response for liquid lubricants under moderate pressures

2001 ◽  
Vol 215 (3) ◽  
pp. 223-233 ◽  
Author(s):  
S Bair
Keyword(s):  
Numerical Simulation ◽  
Kinetic Theory ◽  
Simple Shear ◽  
Pressure Dependence ◽  
Shear Stresses ◽  
Current Interest ◽  
Flow Properties ◽  
Power Law Fluid ◽  
Temperature And Pressure

A thorough characterization of all viscous flow properties relevant to steady simple shear was carried out for five liquid lubricants of current interest to tribology. Shear stresses were generated to values significant to concentrated contact lubrication. Two types of non-Newtonian response were observed: shear-thinning as a power-law fluid and near rate-independence. Functions and parameters were obtained for the temperature and pressure dependence of the viscosity and of the time constant for the Carreau-Yasuda equation. Results are consistent with free volume and kinetic theory, but directly contradict many assumptions currently utilized for numerical simulation and for extracting rheological properties from contact measurements.

Measured temperature and pressure dependence of Vp and Vs in compacted, polycrystalline sI methane and sII methane–ethane hydrate

2003 ◽  
Vol 81 (1-2) ◽  
pp. 47-53 ◽  
Author(s):  
M B Helgerud ◽  
W F Waite ◽  
S H Kirby ◽  
A Nur
Keyword(s):  
High Pressure ◽  
Shear Wave ◽  
Pressure Dependence ◽  
Gas Hydrate ◽  
Pressure Vessel ◽  
Wave Speed ◽  
Measured Temperature ◽  
Shear Wave Speed ◽  
Temperature And Pressure ◽  
Fixed End

We report on compressional- and shear-wave-speed measurements made on compacted polycrystalline sI methane and sII methane–ethane hydrate. The gas hydrate samples are synthesized directly in the measurement apparatus by warming granulated ice to 17°C in the presence of a clathrate-forming gas at high pressure (methane for sI, 90.2% methane, 9.8% ethane for sII). Porosity is eliminated after hydrate synthesis by compacting the sample in the synthesis pressure vessel between a hydraulic ram and a fixed end-plug, both containing shear-wave transducers. Wave-speed measurements are made between –20 and 15°C and 0 to 105 MPa applied piston pressure. PACS No.: 61.60Lj

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