Buffer gas

About: Buffer gas is a research topic. Over the lifetime, 3565 publications have been published within this topic receiving 47283 citations.

Comparison of dielectric breakdown properties for different carbon-fluoride insulating gases as SF6 alternatives

Abstract: As a widely used insulating medium, sulfur hexafluoride (SF6) is a greenhouse gas with very high global warming potential (GWP). Some carbon-fluoride gases have potential to replace SF6 in insulating applications. In order to reveal their different dielectric performance, this paper is devoted to a comparative study of dielectric breakdown properties for SF6 and four carbon-fluoride insulating gases i.e. CF3I, C2F6, C3F8, and c-C4F8 mixed with CO2, N2, and CF4 based on the numerical solution of Boltzmann equation. The electron energy distribution function (EEDF), reduced ionization coefficients α/N, reduced electron attachment coefficients η/N, and reduced critical electric field strength (E/N)cr are compared for various gas mixtures. Generally c-C4F8 presents the largest dielectric strength among the four carbon-fluoride insulating gases whichever buffer gas is mixed, while C2F6 presents the lowest dielectric strength. In terms of (E/N)cr and GWP, CF3I is a good eco-friendly insulating medium. However, with the addition of buffer gases, the (E/N)cr of CF3I mixtures declines more quickly than other mixtures. It is also found that the mixing of CF4 makes insulating mixtures depend more linearly on the proportions of buffer gas than CO2 and N2.As a widely used insulating medium, sulfur hexafluoride (SF6) is a greenhouse gas with very high global warming potential (GWP). Some carbon-fluoride gases have potential to replace SF6 in insulating applications. In order to reveal their different dielectric performance, this paper is devoted to a comparative study of dielectric breakdown properties for SF6 and four carbon-fluoride insulating gases i.e. CF3I, C2F6, C3F8, and c-C4F8 mixed with CO2, N2, and CF4 based on the numerical solution of Boltzmann equation. The electron energy distribution function (EEDF), reduced ionization coefficients α/N, reduced electron attachment coefficients η/N, and reduced critical electric field strength (E/N)cr are compared for various gas mixtures. Generally c-C4F8 presents the largest dielectric strength among the four carbon-fluoride insulating gases whichever buffer gas is mixed, while C2F6 presents the lowest dielectric strength. In terms of (E/N)cr and GWP, CF3I is a good eco-friendly insulating medium. However, w...

Gas sensor for determining the concentration of gas components in gas mixtures and use thereof

Abstract: The invention relates to a gas sensor for determining the concentration of gas components in gas mixtures. Said sensor, in particular, is used for determining the concentration of nitrogen oxides in exhaust gases from internal combustion engines or in the interiors of vehicles. The inventive sensor contains an electrochemical measuring cell disposed on a solid electrolyte, in addition to a first electrode (31) and another electrode (32). The electrode (31) is made of a material comprising an oxide of lanthanum which can at least catalytically degrade nitrogen oxides. The pump stream flowing between the electrodes (31, 32) is used as a reference standard for the nitrogen oxide concentration in the gas mixture.

Spin exchange polarization and measurement of the hyperfine splitting of short-lived8Li

Abstract: Free8Li (T1/2=0.84 sec) atoms were polarized by spin exchange with optically pumped rubidium vapour. The8Li nuclei were produced by the reaction7Li(d, p)8Li in a thin LiF target. They recoiled into helium which was used as a buffer gas for optical pumping as well. Nuclear polarization up to 2% was detected by β-decay asymmetry. Rf transitions between hfs levels of the atomic ground state yielded the hfs separation ΔW=382.543(7) MHz. The nuclear spin assignmentI=2 was confirmed.

Vapor discharge lamp assembly

Abstract: A miniaturized vapor discharge lamp assembly that includes a light transmissive bulb (14) containing a buffer gas and a vaporizable light radiating substance such as rubidium. Lamp excitation is provided by the use of a capacitor in the lamp assembly in conjunction with an RF oscillator (44). The capacitor establishes a substantially longitudinal electric field which ionizes the rubidium vapor to cause emission of light. The need for an RF excitation coil is eliminated.

Degassing treatment of liquid

Abstract: 1531537 Degassing liquid BRITISH PETROLEUM CO Ltd 2 March 1977 [26 March 1976] 12227/76 Heading B1M A method for removing undesirable gas from a liquid in which it is dissolved comprises contacting the liquid co-currently with an inert gas in a static mixer to displace the undesirable gas by the inert gas, passing the resulting mixture of liquid containing dissolved inert gas, free inert gas and undesirable gas to a cyclone separator, and recovering liquid of higher quality. Thus oxygen can be removed from sea water using nitrogen, the sea water then being injected into oil reservoirs.