Chemical nitrous oxide

The narcotic potency and solubiUty in oHve oil of several metabohcaHy inert gases are Hsted in Table 10. The narcotic potency, ED q, is expressed as the partial pressure of the gas in breathing mixtures requited to produce a certain degree of anesthesia in 50% of the test animals. The solubiUties are expressed as Bunsen coefficients, the volume of atmospheric pressure gas dissolved by an equal volume of Hquid. The Hpid solubiHty of xenon is about the same as that of nitrous oxide, a commonly used light anesthetic, and its narcotic potency is also about the same. As an anesthetic, xenon has the virtues of reasonable potency, nonflammability, chemical inertness, and easy elimination by the body, but its scarcity and great cost preclude its wide use for this purpose (see Anesthetics). 

Dielectric Deposition Systems. The most common techniques used for dielectric deposition include chemical vapor deposition (CVD), sputtering, and spin-on films. In a CVD system thermal or plasma energy is used to decompose source molecules on the semiconductor surface (189). In plasma-enhanced CVD (PECVD), typical source gases include silane, SiH, and nitrous oxide, N2O, for deposition of siUcon nitride. The most common CVD films used are siUcon dioxide, siUcon nitride, and siUcon oxynitrides. 

Public concerns about air quality led to the passage of the Clean Air Act in 1970 to amendments to that act in 1977 and 1990. The 1990 amendments contained seven separate titles covering different regula-toiy programs and include requirements to install more advanced pollution control equipment and make other changes in industrial operations to reduce emissions of air pollutants. The 1990 amendments address sulfur dioxide emissions and acid rain deposition, nitrous oxide emissions, ground-level ozone, carbon monoxide emissions, particulate emissions, tail pipe emissions, evaporative emissions, reformulated gasoline, clean-fueled vehicles and fleets, hazardous air pollutants, solid waste incineration, and accidental chemical releases. 

The determination of magnesium in potable water is very straightforward very few interferences are encountered when using an acetylene-air flame. The determination of calcium is however more complicated many chemical interferences are encountered in the acetylene-air flame and the use of releasing agents such as strontium chloride, lanthanum chloride, or EDTA is necessary. Using the hotter acetylene-nitrous oxide flame the only significant interference arises from the ionisation of calcium, and under these conditions an ionisation buffer such as potassium chloride is added to the test solutions. 

Denitrification involves the sequential formation of nitrite, nitric oxide, and nitrous oxide. Two aspects of nitric oxide have attracted attention (a) chemical oxidation of biogenic nitric oxide to Nq, in the context of increased ozone formation (Stohl et al. 1996) and (b) the physiological role in mammalian systems (Feldman et al. 1993 Stuehr et al. 2004), in parasitic infections (James 1995), and in the inhibition of bacterial respiration (Nagata et al. 1998). Nitric oxide may be produced microbiologically in widely different reactions such as... 

In the 1980 s zeolites attracted a renewed attention. They were shown to be rather promising catalysts if, instead of O2, a chemically pre-modified oxygen entering the oxygen-containing molecules is used. The most known example is an excellent catalytic performance of titanium silicalites in the liquid phase oxidations with H2O2 [5]. A gas phase oxidation with nitrous oxide is another approach in this field being intensively developed in the last years [2],... 

Despite several decades of studies devoted to the characterization of Fe-ZSM-5 zeolite materials, the nature of the active sites in N20 direct decomposition (Fe species nuclearity, coordination, etc.) is still a matter of debate [1], The difficulty in understanding the Fe-ZSM-5 reactivity justifies a quantum chemical approach. Apart from mononuclear models which have been extensively investigated [2-5], there are very few results on binuclear iron sites in Fe-ZSM-5 [6-8], These DFT studies are essentially devoted to the investigation of oxygen-bridged binuclear iron structures [Fe-0-Fe]2+, while [FeII(p-0)(p-0H)FeII]+ di-iron core species have been proposed to be the active species from spectroscopic results [9]. We thus performed DFT based calculations to study the reactivity of these species exchanged in ZSM-5 zeolite and considered the whole nitrous oxide catalytic decomposition cycle [10],... 

Organic solvents inhaled by abusers include gasoline, glue, aerosols, amyl nitrite, butyl nitrite, typewriter correction fluid, lighter fluid, cleaning fluids, paint products, nail polish remover, waxes, and varnishes. Chemicals in these products include nitrous oxide, toluene, benzene, methanol, methylene chloride, acetone, methyl ethyl ketone, methyl butyl ketone, trichloroethylene, and trichloroethane. 

Davy, H. (1800) Researches Chemical and Philosophical, Chiefly Concerning Nitrous Oxide iutd its Respiration. J. Johnson, London. 

Other chemical interferences may be overcome by changing oxidants (air or nitrous oxide are the choices) or by changing the fuel-oxidant flow ratio, giving a lower or higher flame temperature. 

The first use of supercritical fluid extraction (SFE) as an extraction technique was reported by Zosel [379]. Since then there have been many reports on the use of SFE to extract PCBs, phenols, PAHs, and other organic compounds from particulate matter, soils and sediments [362, 363, 380-389]. The attraction of SFE as an extraction technique is directly related to the unique properties of the supercritical fluid [390]. Supercritical fluids, which have been used, have low viscosities, high diffusion coefficients, and low flammabilities, which are all clearly superior to the organic solvents normally used. Carbon dioxide (C02, [362,363]) is the most common supercritical fluid used for SFE, since it is inexpensive and has a low critical temperature (31.3 °C) and pressure (72.2 bar). Other less commonly used fluids include nitrous oxide (N20), ammonia, fluoro-form, methane, pentane, methanol, ethanol, sulfur hexafluoride (SF6), and dichlorofluoromethane [362, 363, 391]. Most of these fluids are clearly less attractive as solvents in terms of toxicity or as environmentally benign chemicals. Commercial SFE systems are available, but some workers have also made inexpensive modular systems [390]. 

Q. Zhu, R. M. van Teeffelen, R. A van Santen, and E. J. M. Hensen, Effect of high-temperature treatment on Fe/ZSM-5 prepared by chemical vapor deposition of FeCls 11. Nitrous oxide decomposition, selective oxidation of benzene to phenol, selective reduction of nitrous oxide by MO-butane, J. Catal. 221, 575—583 (2004)... 

Polley, C.W., Jr. Munson, B. Nitrous Oxide As Reagent Gas for Positive Ion Chemical Ionization Mass Spectrometry. Anal Chem. 1983,55, 754-757. 

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