scispace - formally typeset
Search or ask a question

Showing papers on "Buffer gas published in 1969"


Patent
21 Jan 1969
TL;DR: In this paper, the saturation concentration of oxygen in the gas stream is controlled to the desired oxygen partial pressure substantially independent of the total pressure of gas mixture by controlling the temperature of the two-phase cryogenic system.
Abstract: A process for supplying the proper amount of oxygen in a breathing gas mixture of at least one inert gas for use at any pressure by passing the gas mixture through the liquid phase of a cryogenic liquid-vapor system containing oxygen and thereby saturating with oxygen the gas mixture at the system pressure. The saturation concentration of oxygen in the gas stream is controlled to the desired oxygen partial pressure substantially independent of the total pressure of gas mixture by controlling the temperature of the two-phase cryogenic system. A device embodying the process includes oxygen in liquid-vapor form within a container to which are connected gas conduits, one for delivering the saturated breathing gas mixture to a user and the other for returning the exhaled gas to the container. A filter in the return conduit extracts carbon dioxide and water vapor. The return gas is cooled to the cryogenic temperature and the saturated gas is heated to breathing temperature by a heat exchanger thermally connecting the two conduits. The two-phase system is maintained at the proper constant temperature by submerging the container in a tank of liquid nitrogen and allowing the nitrogen to boil-off at a certain pressure. A supply of inert gas is stored under high pressure in the container. A regulator determines total pressure requirements for the user and releases sufficient inert gas through the liquid oxygen to maintain required total pressure.

30 citations


Journal ArticleDOI
TL;DR: In this paper, the rate of photodetachment of O2− has been determined in white light and the rate adjusted to yield a value for the lifetime of O 2− in sunlight.
Abstract: The rate of photodetachment of O2− has been determined in white light and the rate adjusted to yield a value for the lifetime of O2− in sunlight. The technique used was to measure the rate of production of free electrons from ions in a buffer gas of pure oxygen. The buffer gas pressure was high enough to permit any vibrational or electronic excitation to be relaxed by ∼106 collisions with the 300°K oxygen molecules. Identification of the ions was by determination of their mobility. The sunlight photodetachment rate, as determined by the measurement, is 0.3 ± 0.1/sec. The only previous measurements were more controlled in most respects, but they were made on ions with an unknown amount of excitation. Having ions that are relaxed makes the data more relevant for use in applications to the mesosphere. There is the risk that O2− reacts with oxygen to make O4−. If this is true in the present measurement, it is likely to be true in applications also.

24 citations


Journal ArticleDOI
TL;DR: In this paper, a method to eliminate "argon instability" in a Penning cold-cathode ion pump is proposed, which involves the use of a metal having a high sputtering yield coefficient as one of the cathodes.
Abstract: A method to eliminate “argon instability” in a Penning cold-cathode ion pump is proposed. This method involves the use of a metal having a high sputtering yield coefficient as one of the cathodes. The results obtained using titanium and tantalum as cathodes are described. This combination has eliminated the pressure fluctuations while pumping inert gases. The performance characteristics on gases such as air, nitrogen, hydrogen, argon, and helium are also given.

19 citations


Patent
17 Nov 1969
TL;DR: In this article, the authors describe a Gas Filter-SILENCER of limited size with a large number of CONCENTRIC CHAMBERS having an INTERPOSITIONED ANNULAR FILTER.
Abstract: A GAS FILTER-SILENCER OF LIMITED SIZE WITH A PLURALITY OF CONCENTRIC CHAMBERS HAVING AN INTERPOSITIONED ANNULAR FILTER. THE CHAMBERS OF ONE PAIR THEREOF ARE IN GAS FLOW COMMUNICATION BY WAY OF CHOKE TUBES WHICH ARE STRUCTURALLY AND OPERATIVELY DISPOSED THEREBETWEEN. THE CHOKE TUBES DIVIDE THE FILTERED GAS INTO PARALLEL PATHS, EACH OF WHICH EXTEND MORE THAN HALF THE AXIAL LENGTH OF THE FILTERSILENCER, TO SUPPRESS THE NOISE FREQUENCIES OF THE GAS.

14 citations


Patent
20 Aug 1969
TL;DR: In this paper, a light gas stream of increased purity is recovered from a gaseous mixture consisting predominantly of the light gas by passing the mixture through a rotating gas centrifuge under conditions such that gas impurities are condensed.
Abstract: A light gas, namely hydrogen or helium, of increased purity is obtained from a gaseous mixture consisting predominantly of the light gas by passing the mixture through a rotating gas centrifuge under conditions such that gaseous impurities are condensed and a light gas stream of increased purity is recovered. The process may be applied to a light gas concentrate obtained from a gaseous mixture by separation of the constituents other than the light gas by low-temperature condensation, in which case a gas expansion turbine used to produce refrigeration for the process may be used to drive the gas centrifuge.

14 citations


Journal ArticleDOI
TL;DR: In this article, the observation of Dehmelt-type transients for 7 Li in the presence of a buffer gas is reported, and the main problems in the optical orientation of lithium are discussed.

13 citations


Patent
19 May 1969
TL;DR: A metal halide high intensity lamp containing A1C13 and providing a continuous spectrum was used in this article to provide thermodynamic stability against attack of the tungsten electrodes and other lamp metals by chlorine, and an alumina envelope was used which does not react with A 1C13.
Abstract: A metal halide high intensity lamp containing A1C13 and providing a continuous spectrum. Excess aluminum in the filling gives thermodynamic stability against attack of the tungsten electrodes and other lamp metals by chlorine, and an alumina envelope is used which does not react with A1C13. The filling also preferably contains aluminum tri-iodide, mercury for a buffer gas, and an inert gas to facilitate starting.

12 citations


Patent
25 Aug 1969
TL;DR: In this article, a gas sample dispersed in a first carrier gas such as hydrogen is enriched by introducing into the dispersion at a controlled flow rate a mixture of a second carrier gas, such as helium diluted with the first carrier, passing the gas dispersion through a gas transfer device such as a heated palladium tube which is selectively permeable.
Abstract: A gas sample dispersed in a first carrier gas such as hydrogen is enriched by introducing into the dispersion at a controlled flow rate a mixture of a second carrier gas such as helium diluted with first carrier gas and passing the dispersion through a gas transfer device such as a heated palladium tube which is selectively permeable to the first carrier gas.

9 citations


Journal ArticleDOI
TL;DR: In this paper, a one-centre expression for the long-range dispersion contribution to the hyperfine pressure shift of a paramagnetic atom in an inert buffer gas, and the use of oscillator strength sums in the evaluation of the leading term is discussed.
Abstract: A one-centre expression is derived for the long-range dispersion contribution to the hyperfine pressure shift of a paramagnetic atom in an inert buffer gas, and the use of oscillator strength sums in the evaluation of the leading term is discussed. Accurate calculations are carried out for atomic hydrogen in each of the inert gases.

8 citations


Journal ArticleDOI
TL;DR: Gas velocity and pressure influence on electrical breakdown potential of Ar, N and He between parallel flat plate and concentric electrodes as discussed by the authors, in the case of a concentric electrode and a flat plate.
Abstract: Gas velocity and pressure influence on electrical breakdown potential of Ar, N and He between parallel flat plate and concentric electrodes

7 citations


Patent
07 Mar 1969
TL;DR: In this article, the secondary gas may consist of inert gas or one or more gaseous reactants, and it can be introduced in same stream as combustible gas mixture or in transverse stream.
Abstract: (Part of) charge is reacted in flame produced from combustible gas mixture, gas stream (secondary gas) being intermixed in flame front. Secondary gas may consist of inert gas or one or more gaseous reactants. It can be introduced in same stream as combustible gas mixture or in transverse stream. Process is suitable for synthesis of unsaturated 2C hydrocarbons from light hydrocarbons and O2 and HCN from light hydrocarbons, NH3 and O2. Satisfactory yields are attained.


Journal ArticleDOI
TL;DR: In this paper, the same spray transfer is observed by oscillogram as in the case of argon only, but under argon-nitrogen shielding gas metal transfer changes to short circuit type.
Abstract: For the purpose of decreasing blowholes in aluminum weld metal, this experiment was carried out under the shielding gas of argon mixed with nitrogen and/or oxygen.Results obtained are as follows:-1) Blowholes in aluminum deposited metal by MIG welding can be decreased by adding nitrogen and/or oxygen to supplied argon gas. Minimum porosity is obtained respectively for mixing ratios of argon 50%+nitrogen 50%, argon 98.5%+oxygen 6.5% (bead on plate) and argon 98.5%+oxygen 1.5% (I-butt weld).2) In case of argon and oxygen shielding gas, same spray transfer is observed by oscillogram as in the case of argon only, but under argon-nitrogen shielding gas metal transfer changes to short circuit type.