Nitrous oxide atmosphere

Irradiation of Hydrocarbon Polymers in Nitrous Oxide Atmosphere... 

Polypropylene. A similar study on polypropylene is interesting because polypropylene has a molecular structure intermediate between polyethylene and polyisobutylene. An atactic polypropylene specimen was prepared by ether extraction and irradiated in a nitrous oxide atmosphere. The changes in gel fraction (insoluble in hot xylene) as a function of N-jO pressure are shown in Figure 6. Gel formation (cross-linking) of polypropylene is also promoted in the presence of nitrous oxide. 

Figure 26.5. Yield of styrene and selectivities of benzene, toluene, and styrene oxide in nitrogen and nitrous oxide atmospheres as a function of time on stream. Reaction temperature, 623 K Weight Hourly Space Velocity (WHSV) of EB, 1 N2/N2O flow rate, 1200h 20 VOX/AI2O3. Solid symbols = under N2O flow open symbols = under N2 flow. Adapted from Ref. 26.

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). 

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. 

In densely populated areas, traffic is responsible for massive exhausts of nitrous oxides, soot, polyaromatic hydrocarbons, and carbon monoxide. Traffic emissions also markedly contribute to the formation of ozone in the lower parts of the atmosphere. In large cities, fine particle exposure causes excess mortality which varies between one and five percent in the general population. Contamination of the ground water reservoirs with organic solvents has caused concern in many countries due to the persistent nature of the pollution. A total exposure assessment that takes into consideration all exposures via all routes is a relatively new concept, the significance of which is rapidly increasing. 

Nitrous oxide is a long-lived warming gas with a relative warming strength 170 to 310 times that of carbon dioxide, depending on the time scale one considers. Nitrous oxide, like methane, is considered a trace gas in the atmosphere, but at considerably lower... 

Excess fertilizer and combustion processes also can increase nitrous oxide (NnO) and nitrogen oxides (NOx) in the atmosphere. Nitrous oxide is a powerful greenhouse gas, and nitrogen oxides lead to smog and acid rain. The production of fertilizers requires a great deal of energy. The use of fossil fuels to supply the thermal requirements for fertilizer production further increases emission of nitrogen compounds to the atmosphere. 

Assuming the randomness factor is about the same, the gas with the larger heat effect (favoring dissolving) should have the higher solubility. The measured solubilities at one atmosphere pressure and 20°C of oxygen and nitrous oxide in water are, respectively, 02, 1.4 X 10-3 mole/liter and N20, 27 X 10-3 mole/liter, consistent with our prediction.. 

From the heat of solution of chlorine in water, —6.0 kcal/mole (heat evolved), how do you expect the solubility of chlorine at one atmosphere pressure and 20°C to compare with that of oxygen and of nitrous oxide, N20 ... 

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. 

The interstitial air trapped during this process preserves a largely unaltered record of the composition of past atmospheres on time scales as short as decades and as long as several hundred thousand years. Such records have provided critical information about past variations in carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), carbon monoxide (CO), and the isotopic composition of some of these trace species. In addition, studies of the major elements of air nitrogen, oxygen, and argon, and their isotopic composition, have contributed... 

Machida, T., Nakazawa, T., Fujji, Y. et al. (1995). Increase in atmospheric nitrous oxide concentration during the last 250 years. Geophys. Res. Lett. 22, 2921-2924. 

Commercially produced amines contain Impurities from synthesis, thus rigid specifications are necessary to avoid unwanted Impurities In final products. Modern-day analytical capability permits detection of minute quantities of Impurities In almost any compound. Detection In parts per million Is routine, parts per billion Is commonplace, and parts per trillion Is attainable. The significance of Impurities In products demands careful and realistic Interpretation. Nltrosatlng species, as well as natural amines, are ubiquitous In the environment. For example, Bassow (1976) cites that about 50 ppb of nitrous oxide and nitrogen dioxide are present In the atmosphere of the cities. Microorganisms In soil and natural water convert ammonia to nitrite. With the potential for nitrosamine formation almost ever-present In the envlronmeit, other approaches to prevention should Include the use of appropriate scavengers as additives In raw materials and finished products. 

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