Nitrous oxides sources

Nevison, C., Lueker, T., and Weiss, R. F. (2004). Quantifying the nitrous oxide source from coastal upweUing. Global Biogeochem. Cycles 18, GB1018, doi 10.1029/2003GB002110. 

Robertson G. P. and Tiedje J. M. (1987) Nitrous oxide sources in aerobic soils nitrification, denitrification and other biological processes. Soil Biol Biochem. 19, 187-193. 

Figure 2 Atmospheric nitrous oxide sources and sinks (adaptedfrom Houghton eta ., 1995). Units Tg = 1 x lO g.

As explained above, the derivation of global source estimates for N2O, NOx, COS and CH3CI is not trivial. The resulting fluxes which we will derive for these gases are, therefore, less reliable than those derived for CO, H2 and CH4. The simplest way of estimating the flux would be to apply the same procedure as for CO, H2 and CH4. With an approximate N2O/CO2 emission factor of 0.22 %, the estimated nitrous oxide source would be 20 x 10 g N2O year . Similar calcu-... 

Gate oxide dielectrics are a cmcial element in the down-scaling of n- and -channel metal-oxide semiconductor field-effect transistors (MOSEETs) in CMOS technology. Ultrathin dielectric films are required, and the 12.0-nm thick layers are expected to shrink to 6.0 nm by the year 2000 (2). Gate dielectrics have been made by growing thermal oxides, whereas development has turned to the use of oxide/nitride/oxide (ONO) sandwich stmctures, or to oxynitrides, SiO N. Oxynitrides are formed by growing thermal oxides in the presence of a nitrogen source such as ammonia or nitrous oxide, N2O. Oxidation and nitridation are also performed in rapid thermal processors (RTP), which reduce the temperature exposure of a substrate. 

Effect of Nitric Oxide on Ozone Depletion. Nitrous oxide is injected into the atmosphere from natural sources on earth about 10% is converted to nitric oxide (N20 + 0( D) — 2 NO), which in turn can catalyze the destmction of ozone (11,32,75). The two main cycles are 1 and 2. Rate constant data are given in Reference 11. 

Quantitative aluminum deterrninations in aluminum and aluminum base alloys is rarely done. The aluminum content is generally inferred as the balance after determining alloying additions and tramp elements. When aluminum is present as an alloying component in alternative alloy systems it is commonly deterrnined by some form of spectroscopy (qv) spark source emission, x-ray fluorescence, plasma emission (both inductively coupled and d-c plasmas), or atomic absorption using a nitrous oxide acetylene flame. 

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. 

Two colorimetric methods are recommended for boron analysis. One is the curcumin method, where the sample is acidified and evaporated after addition of curcumin reagent. A red product called rosocyanine remains it is dissolved in 95 wt % ethanol and measured photometrically. Nitrate concentrations >20 mg/L interfere with this method. Another colorimetric method is based upon the reaction between boron and carminic acid in concentrated sulfuric acid to form a bluish-red or blue product. Boron concentrations can also be deterrnined by atomic absorption spectroscopy with a nitrous oxide—acetjiene flame or graphite furnace. Atomic emission with an argon plasma source can also be used for boron measurement. 

Table 6 Estimated sources of nitrous oxide (TG Nyr ) (IPCC) ...

Nitrogen oxides (of which nitrous oxide is the major component) come from a variety of sources, only some of which are of human origin. 

Bremner, J. M. and Blackmer, A. M. (1981). Terrestrial nitrification as a source of atmospheric nitrous oxide. In Denitrification, Nitrification, and Atmospheric Nitrous Oxide" (C. C. Delwiche, ed.). Wiley, New York. 

Nitrous oxide has received increasing attention the last decade, due to the growing awareness of its impact on the environment, as it has been identified as an ozone depletion agent and as a Greenhouse gas [1]. Identified major sources include adipic acid production, nitric acid and fertilizer plants, fossil fuel and biomass combustion and de-NOx treatment techniques, like three-way catalysis and selective catalytic reduction [2,3]. 

Much interest is noted in the development of catalysts that decompose nitrous oxide into its elements, at rates and conditions that are compatible with the production sources. 

Mark H. Thiemens and William C. Trogler. Nylon Production An Unknown Source of Atmospheric Nitrous Oxide. Science. 251 (Feb. 22, 1991) 932-934. 

William C. Trogler. e-mail communication, Sept. 25, 2000. Source for DuPont reaction to his nitrous oxide discovery. 

Abstract Presently, a growing interest is focused on unregulated emissions of nitrous oxide (N20) from stationary and mobile sources in order to anticipate future restrictive legislations, since N20 exhibits a significant higher global warming power than that of C02. 

The conventional selective reduction of NOx for car passengers still competes but the efficient SCR with ammonia on V205/Ti02 for stationary sources is not available for mobile sources due to the toxicity of vanadium and its lower intrinsic activity than that of noble metals, which may imply higher amount of active phase for compensation. As illustrated in Figure 10.9, such a solution does not seem relevant because a subsequent increase in vanadium enhances the formation of undesirable nitrous oxide at low temperature. Presently, various attempts for the replacement of vanadium did not succeed regarding the complete conversion of NO into N2 at low temperature. Suarez et al. [87] who investigated the reduction of NO with NH3 on CuO-supported monolithic catalysts... 

Kool DM., Dolfing J, Wrage N, Van Groenigen JW. Nitrifier denitrification as a distinct and significant source of nitrous oxide from soil. Soil Biology Biochemistry. 2011 43 174-178. DOI 10.1016/j.soilbio.2010.09.030... 

Energy production and consumption pose nature into pressure and make the energy sector becomes the largest contributor of greenhouse gas (GHG) emission in Vietnam since 2010, accounting for 67%. Several emission sources of GHG could be found in a waste treatment facilities it came from (1) emission of methane (CH4, GWP 25) at landfill of mixed waste, (2) from emission of fossil carbon dioxide through the combustion of plastics and composites or supported fuels (auxiliary), and (3) from emission of nitrous oxide (NOx) during incineration/ pretreatment process, etc. 

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