A reaction kinetic approach to the temperature-time history of sedimentary basins

Author(s):  
Cs. Sajgó ◽  
J. Lefler

2017 ◽  
Vol 125 (6) ◽  
pp. 659-680 ◽  
Author(s):  
R. A. Hardie ◽  
D. A. Schneider ◽  
J. I. Garver


Author(s):  
W. S. Affleck

When the ignition of a car engine is switched off, the engine normally comes to rest within a few revolutions but, occasionally, it may continue to fire erratically for a few seconds or longer. This phenomenon is known as run-on and, for the majority of European engines, is the result of spontaneous ignition of the fuel-air mixture in the combustion chamber. Part 1 of this paper describes experiments in a single-cylinder research engine which have been made to establish the principles controlling run-on. In particular the effects of air/fuel ratio, the nature of the fuel and the pressure-temperature-time history of the fuel-air mixture in the combustion chamber have been studied, as it is known that these factors play an important part in spontaneous ignition in experiments in laboratory vessels. From these observations it has been possible to formulate a theoretical model of the run-on process which explains the salient features of the phenomenon. In particular, it shows how the gradual cooling of the engine limits the duration of run-on and also how the duration of run-on may be considered as a measure of the extent to which fuel or engine factors must be altered to eliminate run-on. Part 2 describes the application of these principles to car engines using normal commercial-type fuels. It is concluded that the following are important features in the control of run-on: the use of fuel of sufficiently high Research octane number, minimum opening of throttle at idle, sufficient time for cooling of the combustion chamber before the ignition is switched off, efficient engine cooling, and small valve overlap. Current devices for reducing exhaust emissions are likely, through their effects on these features, to increase the tendency of an engine run-on. Combustion chamber deposits, though, appear to have little influence.



2001 ◽  
Vol 16 (8) ◽  
pp. 2421-2428 ◽  
Author(s):  
D. Josell ◽  
D. Basak ◽  
J. L. McClure ◽  
U. R. Kattner ◽  
M. E. Williams ◽  
...  

Pulsed heating experiments that measure high-temperature thermophysical properties using pyrometric measurement of the temperature–time history of metal specimens rapidly heated by passage of electric current have a 30-year history at the National Institute of Standards and Technology. In recent years, efforts have been made to move beyond the limitations of the standard technique of using costly, black-body geometry specimens. Specifically, simultaneous polarimetry measurement of the spectral emissivity has permitted study of sheet and wire specimens. This paper presents the results of two efforts to expand beyond the macroscopically monolithic, single-phase materials of all previous studies. In the first study the melting temperatures of coatings, including Ti and Ti(Al) alloys, deposited on higher melting Mo substrates are measured. In the second study the melting temperatures of substrates, Ti and Cr, covered by higher melting W and Mo coatings are measured.



Author(s):  
A.C. Leger ◽  
A. Haddadi ◽  
B. Pateyron ◽  
G. Delluc ◽  
A. Grimaud ◽  
...  

Abstract A simplified ID model has been developed to calculate the temperature time history of alumina layering splats. The splats were obtained by plasma spraying alumina fused and crushed particles (- 45 + 22 µm). The model has shown that for more than 160-200 µm layered splats the solidification time is over 7-10 µs, When spraying thin passes (ep < 15 µm) each splat cools down to substrate preheating temperature before next splat impacts. On the contrary for thick passes (ep = 60 or 180 µm), after depositing a certain thickness (between 160 and 200 µm) depending on spraying conditions, the temperature of the splats never drops below 800-900 K (mean splat temperature). In this case nucleation occurs after flattening is completed. Such conditions allow a columnar growth through the layered splats of each pass and successive passes. The study of the corresponding stresses (quenching σq and expansion mismatch) generated when spraying alumina on XC38 sheet was measured by following continuously the bending of a beam. The comparison of the measurements with the results of a ID model developed by Tsui and Clyne has allowed to calculate the coating Young's modulus Ed and the residual stresses difference at the interface. For thin coatings σq and Ed increase with preheating temperature. For thick coatings the values of Ed and σq are lower than the highest ones of thin coatings. This is probably due to stress relaxation by cracks propagation, the quenching and expansion mismatch stresses increasing with the increasing mean splat temperature.



2003 ◽  
Vol 88 (8-9) ◽  
pp. 1300-1311 ◽  
Author(s):  
Frank E. Brenker ◽  
Wolfgang Friedrich Müller ◽  
Gerhard P. Brey


1989 ◽  
Vol 29 (1) ◽  
pp. 130
Author(s):  
P.W. Baillie ◽  
N.J. Russell

Over the last three decades organic metamorphism (coalification), as indicated by changes in vitrinite reflectivity, has been regarded as a function of both temperature and heating duration. This temperature- time concept of coalification has been developed into sophisticated computer programs to model the palaeo- geothermal history of sedimentary basins. However, several papers, published over the last six years, have presented evidence to support the view that, for heating times in excess of 0.001- 1 Ma, vitrinite reflectivity constitutes an absolute palaeogeothermometer. This proposition is broadly supported by a comparison between corrected bottom- hole temperature (BHT) and vitrinite reflectivity data from offshore petroleum exploration wells drilled in Tasmanian waters. Most of the corrected BHT/vitrinite reflectivity data pairs plot on, adjacent to or between two of the published vitrinite temperature/reflectance trends. Although these data indicate that some formations are at, or near, maximum palaeotemperature, there is clear evidence to suggest that many samples, in particular those from formations in the deeper well sections, have cooled significantly below maximum palaeotemperature. It appears that present- day geothermal gradients for some of the wells, based on corrected BHT data, are much less than maximum palaeogeothermal gradients inferred from the vitrinite depth/reflectance relationship.



Tectonics ◽  
1990 ◽  
Vol 9 (5) ◽  
pp. 1165-1195 ◽  
Author(s):  
Elizabeth R. Schermer ◽  
Daniel R. Lux ◽  
B. Clark Burchfiel


Lithos ◽  
2009 ◽  
Vol 113 (3-4) ◽  
pp. 801-819 ◽  
Author(s):  
Marco Beltrando ◽  
Gordon S. Lister ◽  
Marnie Forster ◽  
W. James Dunlap ◽  
Geoff Fraser ◽  
...  


1973 ◽  
Vol 95 (2) ◽  
pp. 246-249 ◽  
Author(s):  
F. C. Wessling ◽  
P. L. Blackshear

This paper presents calculations of the density, thermal conductivity, and enthalpy of blood during the freezing process. The calculations are based upon the premise that blood freezes similarly to a mixture of fats, proteins, and sodium chloride in a water solution and freezes so that ice crystals align themselves with the direction of heat flow. The properties were checked by calculating the theoretical temperature–time history of blood freezing in a Teflon-coated stainless-steel tube and comparing the results with experiments. The agreement was within 10 percent over the entire ranges of temperature and time. Hence the derived thermal properties are concluded to be good approximations to the real properties.



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