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.

Reduced-Pressure Inductively Coupled Plasma Mass Spectrometry for Nonmetallic Elements

1996 ◽  
Vol 50 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Xiaomei Yan ◽  
Tomokazu Tanaka ◽  
Hiroshi Kawaguchi
Keyword(s):  
Atmospheric Pressure ◽  
Inductively Coupled Plasma ◽  
Gas Flow ◽  
Ion Source ◽  
Reduced Pressure ◽  
Inductively Coupled ◽  
Sampling Orifice ◽  
High Ionization ◽  
Order Of Magnitude ◽  
Plasma Mass Spectrometry

A reduced-pressure argon inductively coupled plasma (ICP) is interfaced to a mass spectrometer to evaluate its possibility of increasing the sensitivity of nonmetallic elements. An electrostatically shielded water-cooled torch is used for the investigation of the secondary discharge at the sampling orifice. Iodine vapor is continuously introduced into the torch as an analyte by using a peristaltic pump. The effects of plasma operating parameters such as gas flow rate, pressure, and power on the intensities of background and iodine ions are studied. It is shown that when the pressure is less than about 30 Torr, an intensive secondary discharge occurs at the sampling orifice if the torch shield is not grounded. The background ion intensity and secondary discharge effect decrease with increasing pressure. The pressure in the torch has an important effect on both polyatomic and analyte intensities. At about 130 Torr of torch pressure, the iodine signal is more than one order of magnitude higher than that obtained at atmospheric pressure, which suggests that low-pressure ICP provides a sensitive ion source for the elements with high ionization potential.

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.

Effect of Precursory Cooling on Falling-Film Rewetting

1975 ◽  
Vol 97 (3) ◽  
pp. 360-365 ◽  
Author(s):  
K. H. Sun ◽  
G. E. Dix ◽  
C. L. Tien
Keyword(s):  
Atmospheric Pressure ◽  
Present Model ◽  
Front Velocity ◽  
Falling Film ◽  
Vapor Mixture ◽  
Thin Slab ◽  
Flow Rates ◽  
Variable Flow ◽  
Order Of Magnitude ◽  
Hot Surface

An analytical model for falling-film wetting of a hot surface has been developed to account for the effect of cooling by droplet-vapor mixture in the region immediately ahead of the wet front. The effect of precursory cooling is characterized by a heat transfer coefficient decaying exponentially from the wet front. Based on the present model, the wet front velocity, as well as the temperature profile along a thin slab, can be calculated. It is demonstrated that the precursory cooling can increase the wet front velocity by an order of magnitude. Existing experimental data with variable flow rates at atmospheric pressure are shown to be successfully correlated by the present model.

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.

Effect of Environmental Materials on Aqueous Corrosion of R7T7 Glass

1988 ◽  
Vol 127 ◽  
Author(s):  
N. Godon ◽  
E. Vernaz ◽  
J. H. Thomassin ◽  
J. C. Touray
Keyword(s):  
Atmospheric Pressure ◽  
Test Results ◽  
Aqueous Corrosion ◽  
Environmental Material ◽  
Environmental Materials ◽  
Activated Bentonite ◽  
Order Of Magnitude ◽  
Glass Specimen ◽  
Icp Analysis ◽  
Glass Behavior

ABSTRACTR7T7 glass behavior was investigated in contact with eleven different materials including smectites, bentonites, illites, granite and sand. The experiments were conducted at 90°C under atmospheric pressure with a 4 cm−1 SA/V ratio using two grams of material in double distilled water under static leaching conditions without renewal of the leachate. For each material a control test was conducted under the same conditions but without the glass specimen, as well as a series of tests on glass alone, without the environmental material. Kinetics studies lasting up to 364 days were performed on four selected materials.The test results (mass loss, ICP analysis of the leachates, SEM and TEM observations) showed relatively slight glass alteration in contact with sand, granite and one bentonite (i.e. the same order of magnitude as glass alone in deionized water), but greater alteration of glass in contact with all the other clays.The significant differences in glass behavior in contact with environmental materials can be accounted for by the behavior of the latter in solution: activated bentonite releases very large amounts of silicon and sodium into solution while smectite seems to remove silicon from solution.

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.

Effects of Atmospheric Pressure Plasma Electrode Structure on Silicon Carbide Removal Function

2020 ◽  
Vol 47 (10) ◽  
pp. 1002002
Author(s):  
宋力 Song Li ◽  
顿爱欢 Dun Aihuan ◽  
王哲 Wang Zhe ◽  
吴伦哲 Wu Lunzhe ◽  
彭冰 Peng Bing ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Electrode Structure ◽  
Pressure Plasma ◽  
Plasma Electrode

scholarly journals Vertical Field Emission Air-Channel Diodes and Transistors

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 858 ◽  
Author(s):  
Wen-Teng Chang ◽  
Hsu-Jung Hsu ◽  
Po-Heng Pao
Keyword(s):  
Metal Oxide ◽  
Atmospheric Pressure ◽  
High Speed ◽  
Ambient Pressure ◽  
Electron Flow ◽  
Mean Free Path ◽  
Oxide Semiconductor ◽  
Radiation Environment ◽  
Reduced Pressure ◽  
Transport Distance

Vacuum channel transistors are potential candidates for low-loss and high-speed electronic devices beyond complementary metal-oxide-semiconductors (CMOS). When the nanoscale transport distance is smaller than the mean free path (MFP) in atmospheric pressure, a transistor can work in air owing to the immunity of carrier collision. The nature of a vacuum channel allows devices to function in a high-temperature radiation environment. This research intended to investigate gate location in a vertical vacuum channel transistor. The influence of scattering under different ambient pressure levels was evaluated using a transport distance of about 60 nm, around the range of MFP in air. The finite element model suggests that gate electrodes should be near emitters in vertical vacuum channel transistors because the electrodes exhibit high-drive currents and low-subthreshold swings. The particle trajectory model indicates that collected electron flow (electric current) performs like a typical metal oxide semiconductor field effect-transistor (MOSFET), and that gate voltage plays a role in enhancing emission electrons. The results of the measurement on vertical diodes show that current and voltage under reduced pressure and filled with CO2 are different from those under atmospheric pressure. This result implies that this design can be used for gas and pressure sensing.

scholarly journals Ultra-small photoluminescent silicon-carbide nanocrystals by atmospheric-pressure plasmas

Nanoscale ◽  
2016 ◽  
Vol 8 (39) ◽  
pp. 17141-17149 ◽  
Author(s):  
Sadegh Askari ◽  
Atta Ul Haq ◽  
Manuel Macias-Montero ◽  
Igor Levchenko ◽  
Fengjiao Yu ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasmas
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