scholarly journals Features of processes in a microwave discharge in water vapor

2021 ◽  
pp. 5-10
Author(s):  
Yurii Lebedev ◽  
Alekcey Tatarinov ◽  
Irina Epstein ◽  
Alexander Titov
Keyword(s):  
Water Vapor ◽  
Atmospheric Pressure ◽  
Microwave Field ◽  
Microwave Discharge ◽  
Specific Power ◽  
Gas Temperature ◽  
Reduced Pressure ◽  
Joint Solution ◽  
Steady State Simulation ◽  
Reduced Pressures

A zero-dimensional steady-state simulation of microwave discharge in water vapor at atmos-pheric and reduced pressures and a constant gas temperature has been carried out. A model of a continuous stirring reactor is used. A joint solution of the balance equations for neutral and charged plasma components, the Boltzmann equation for plasma electrons, and the equation for the stationary distribution of the microwave field in a volume filled with plasma is carried out. The dependences of various parameters of thedischarge (the magnitude of the microwave field, the concentrations of all components) on the input specific power WVare obtained. It is shown that at reduced pressure the magnitude of the microwave field in the plasma is signifi-cantly lower, and the electron concentration is higher than at atmospheric pressure at the same applied specific power. At atmospheric pressure the water plasma is electronegative, and quasi-neutrality is maintained by the negative OH-ion in the range of the considered WV values. Transition from electronegative to electropositive plasma occurs at pressure of 30 Torr and ap-plied specific power of 60–70 kW/cm3

Responses of Pests to Fumigation. III.—The Fumigation of Wheat containing Calandra spp.(Curculionidae) with three Fumigants, under Reduced Pressure

1953 ◽  
Vol 44 (4) ◽  
pp. 641-650 ◽  
Author(s):  
A. K. M. El Nahal
Keyword(s):  
Ethylene Oxide ◽  
Methyl Bromide ◽  
Hydrogen Cyanide ◽  
Atmospheric Pressure ◽  
Experimental Conditions ◽  
Reduced Pressure ◽  
Biological Assays ◽  
Moisture Contents ◽  
Reduced Pressures ◽  
Multifactorial Experiment

Wheat of three moisture contents was fumigated with ethylene oxide, methyl bromide and hydrogen cyanide. Both chemical and biological assays were used to follow the changing distribution of the fumigant when applied with sustained vacuum, in a vacuum fumigation with simultaneous admission of air and fumigant, or at atmospheric pressure.As these various factors were altered, in a multifactorial experiment, the changes in the fumigant distribution were also recorded chemically, and then analysed statistically. Changes in the mortality of both species of Calandra, either buried in a one-cwt sack of wheat or in the free-space, were estimated so that that part of the changes which was associated with the altered fumigant distribution was segregated by a covariance analysis and the remainder formed an estimate of the direct influence of the experimental Conditions on the susceptibility of the weevils to the fumigants.When either ethylene oxide or methyl bromide is used as a fumigant for wheat, vacuum fumigation with simultaneous admission of air and fumigant gives results, in terms of the control of Calandra spp., which are almost indistinguishable from those obtained at atmospheric pressure under comparable conditions. When hydrogen cyanide is the fumigant, atmospheric fumigation is superior, quite apart from the capital expense and other practical disadvantages of fumigations at reduced pressures.

Theoretical Study of Plasma Parameters Dependence on Gas Temperature in an Atmospheric Pressure Argon Microwave Discharge

2008 ◽  
Author(s):  
M. Pencheva ◽  
E. Benova ◽  
I. Zhelyazkov ◽  
Hans-Jürgen Hartfuss ◽  
Michel Dudeck ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Theoretical Study ◽  
Microwave Discharge ◽  
Gas Temperature ◽  
Plasma Parameters

Epitaxial Silicon Layers Made by Reduced Pressure/Temperature CVD

1988 ◽  
Vol 129 ◽  
Author(s):  
J.L. Regolini ◽  
D. Bensahel ◽  
J. Mercier ◽  
C. D'Anterroches ◽  
A. Perio
Keyword(s):  
Thermal Processing ◽  
Atmospheric Pressure ◽  
Rapid Thermal Processing ◽  
Processing System ◽  
Epitaxial Silicon ◽  
Reduced Pressure ◽  
Selective Epitaxial Growth ◽  
Main Decomposition ◽  
Rate Limiting ◽  
Reactive Gas

ABSTRACTIn a rapid thermal processing system working at a total pressure of a few Torr, we have obtained selective epitaxial growth of silicon at temperatures as low as 650°C. When using SiH2Cl2 (DCS) as the reactive gas, no addition of HCl is needed. Nevertheless, using SiH4 below 950°C a small amount of HCl should be added.Some kinetic aspects of the two systems, DCS/HCI/H2 and SiH4/HCl/H2, are presented and discussed. For the DCS system, we show that the rate-limiting reactions are slightly different from those commonly accepted in the literature, where the results are from systems working at atmospheric pressure or in the 20-100 Torr range.Our model is based on the main decomposition of DCS, SiH2Cl→SiHCl + HCl, instead of the widely accepted reaction SiH2Cl2→SiCl2 + H2. This is the main reason why no extra HCl is required in the DCS/H2 system to obtain full selectivity from above 1000°C down to 650°C.

scholarly journals Static and Motional Feedthrough Capacitance of Flexural Microresonator

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Wen-Teng Chang
Keyword(s):  
Silicon Carbide ◽  
Atmospheric Pressure ◽  
Network Analyzer ◽  
Reduced Pressure ◽  
Flexural Mode ◽  
Microelectromechanical System ◽  
Order Of Magnitude ◽  
Bode Plots

The present paper evaluates the static and motional feedthrough capacitance of a silicon carbide-based flexural-mode microelectromechanical system resonator. The static feedthrough capacitance was measured by a network analyzer under atmospheric pressure. The motional feedthrough was obtained by introducing various values into the modeling circuit in order to fit the Bode plots measured under reduced pressure. The static feedthrough capacitance was 0.02 pF, whereas the motional feedthrough capacitance of an identical device was about 0.2 pF, which is one order of magnitude larger than the static feedthrough capacitance.

Electron Density and Gas Temperature from Line Broadening in an Argon Surface-Wave-Sustained Discharge at Atmospheric Pressure

2004 ◽  
Vol 58 (9) ◽  
pp. 1032-1037 ◽  
Author(s):  
M. Christova ◽  
E. Castaños-Martinez ◽  
M. D. Calzada ◽  
Y. Kabouzi ◽  
J. M. Luque ◽  
...  
Keyword(s):  
Surface Wave ◽  
Electron Density ◽  
Atmospheric Pressure ◽  
Gas Temperature ◽  
Line Broadening ◽  
Sustained Discharge

scholarly journals The influence of pressure on the boiling points of metals

1910 ◽  
Vol 83 (565) ◽  
pp. 483-491 ◽  
Keyword(s):  
Atmospheric Pressure ◽  
Boiling Point ◽  
High Vacuum ◽  
Similar Type ◽  
Exact Relation ◽  
Reduced Pressure ◽  
Boiling Points ◽  
Experimental Values ◽  
Low Pressures ◽  
Very High

Part I. — Pressures below 760 mm . In a previous communication (‘Proc.’, A, vol. 82, 1909, p. 396) the approximate boiling points of a number of metals were determined at atmospheric pressure. Apart from the question of finding the exact relation between the boiling point and pressure, it is an important criterion of any method for fixing the temperatures of ebullition to demonstrate that the experimental values obtained are dependent on the pressure. It is specially desirable when dealing with substances boiling at temperatures above 2000° to have some evidence that the points indicated are true boiling points. Previous work on the vaporisation of metals at different pressures has been confined to experiments in a very high vacuum except for metals like bismuth, cadmium, and zinc, which boil at relatively low temperatures under atmospheric pressure. The observations were limited to very low pressures on account of the difficulty of obtaining any material capable of withstanding a vacuum at temperatures over 1400° and the consequent necessity for keeping the boiling point below this limit by using very low pressures. Moreover in the case of the majority of the metals, e. g. , copper, tin, ebullition under reduced pressure has never been observed. The difficulties indicated above were avoided by using a similar type of apparatus to that previously described, and arranging the whole furnace inside a vacuum enclosure, thus permitting of the use of graphite crucibles to contain the metal.

scholarly journals Comments on nitrogen excretion from the diver’s organism during the reduced pressure at the final decompression station (< 1 ata)

2016 ◽  
Vol 54 (1) ◽  
pp. 31-36
Author(s):  
Tadeusz Doboszyński ◽  
Bogdan Łokucijewski
Keyword(s):  
Sea Level ◽  
Atmospheric Pressure ◽  
Mountain Lakes ◽  
Air Transport ◽  
Nitrogen Excretion ◽  
Reduced Pressure ◽  
Proper Consideration

Abstract The authors discuss the effect of reduced pressure at the final decompression station on nitrogen excretion from the organism of a diver. The assumed basis for the said considerations was the course of decompression during dives performed in lakes located at a significant altitude above sea level and diver transportation by plane following dive completion. Based on the presented calculations the authors conclude that air transport can take place only upon the lapse of time calculated with regard to the diving conditions and the expected altitude of the flight. Diving in mountain lakes requires proper consideration of the effects of the decreased atmospheric pressure.

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