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.

Sea Level in Relation to Atmospheric Pressure

1926 ◽  
Vol 16 (2) ◽  
pp. 346
Author(s):  
H. A. Marmer ◽  
Alfred Wegener ◽  
A. T. Doodson ◽  
Sinkiti Ogura
Keyword(s):  
Sea Level ◽  
Atmospheric Pressure

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.

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 Detection and Characterization of Meteotsunamis in the Gulf of Genoa

2019 ◽  
Vol 7 (8) ◽  
pp. 275 ◽  
Author(s):  
Picco ◽  
Schiano ◽  
Incardone ◽  
Repetti ◽  
Demarte ◽  
...  
Keyword(s):  
Sea Level ◽  
Atmospheric Pressure ◽  
Tidal Elevation ◽  
Port Management ◽  
Time Frequency ◽  
Abrupt Jump ◽  
Level Data ◽  
Work Planning

A long-term time series of high-frequency sampled sea-level data collected in the port of Genoa were analyzed to detect the occurrence of meteotsunami events and to characterize them. Time-frequency analysis showed well-developed energy peaks on a 26–30 minute band, which are an almost permanent feature in the analyzed signal. The amplitude of these waves is generally few centimeters but, in some cases, they can reach values comparable or even greater than the local tidal elevation. In the perspective of sea-level rise, their assessment can be relevant for sound coastal work planning and port management. Events having the highest energy were selected for detailed analysis and the main features were identified and characterized by means of wavelet transform. The most important one occurred on 14 October 2016, when the oscillations, generated by an abrupt jump in the atmospheric pressure, achieved a maximum wave height of 50 cm and lasted for about three hours.

Continental shelf waves and their influence on the circulation around the Great Barrier Reef

1983 ◽  
Vol 34 (1) ◽  
pp. 23 ◽  
Author(s):  
E Wolanski ◽  
AF Bennett
Keyword(s):  
Continental Shelf ◽  
Great Barrier Reef ◽  
Sea Level ◽  
Atmospheric Pressure ◽  
Low Frequency ◽  
Internal Tides ◽  
Wind Component ◽  
Barrier Reef ◽  
Longshore Current ◽  
Shelf Waves

Winds and atmospheric pressure, sea level and water currents were measured at several locations over the continental shelf, both east and west of the Great Barrier Reef, between 14.5�s. and 20�S., from June to November 1980. The dominant wind direction changed from westward over the Coral Sea to north- westward (roughly parallel to the shore) over the shelf. A strong non-tidal low-frequency signal in all sea- level and longshore current data was found, highly coherent from site to site and strongly correlated with the longshore wind component over the shelf, though not with the atmospheric pressure. A model of wind- driven barotropic shelf waves is used to explain a number of observations, such as the invariance of temporal fluctuations of longshore current with distance from shore, and the northward longshore propagation of oceanic disturbances at a speed equal to twice that of the first-mode barotropic free shelf wave, a speed one order of magnitude smaller than that of the wind system. The low-frequency current fluctuations resulted in large water displacements, up and down the coast. Low-frequency cross-shelf currents were much weaker and less coherent. Two upwelling mechanisms are internal tides and internal Kelvin waves coupled to the barotropic shelf waves.

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.

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