Effects of Reducing Atmosphere

Farnell, P.L, Campbell, C. and Taylor F.R. (1989) Effect of reduced atmospheric pressure on the performance characteristics of pyrotechnic compositions containing aluminum. ARAED-TR-89024, Picatinny Arsenal, Dover, NJ. 

Effect of the Atmosphere. The composition of radiolysis products depends substantially on the degree of saturation of the irradiated system with oxygen. In a nitrogen atmosphere, the major radiolysis products of the system TBP-diluent-HN03 were alkyl-nitro and -nitrate compounds. However, in the presence of oxygen, the yields of these compounds were sharply reduced, and an accumulation of carbonyl compounds was measured (11, 25). 

Air at 207 kPa and 200°C enters a 2.5-cm-ID tube at 6 m/s. The tube is constructed of copper with a thickness of 0.8 mm and a length of 3 m. Atmospheric air at 1 atm and 20°C flows normal to the outside of the tube with a free-stream velocity of 12 m/s. Calculate the air temperature at exit from the tube. What would be the effect of reducing the hot-air flow in half ... 

Measurements of the concentration of OH radicals in the stratosphere in the altitude range 34—37 km have been made by balloon-borne LIDAR. The first post-sunset concentration levels were reported and comparisons were made with current 1-dimensional models. The effects of reduced absorption cross-sections for O2 in the Herzberg continuum on the composition of the stratosphere have been examined by Brasseur et ai., " following the suggestion that laboratory values for the cross-sections might be overestimated by as much as 30—50%. A model for the circulation of atmospheric CO has been described by Pinto et and which includes photochemical production and... 

Effect of Initial NO2 Concentration. In laboratory studies conducted to simulate atmospheric photochemical smog, a serious effort is usually made to start the experiment with low initial concentrations of NO2. In the data of Altshuller et al. studied here [N02]o was 0.05 ppm in other studies [N02]o had lower values (15, 16, 17, 18, 19, 20), and in most of the studies reported [N02]o was not even specified. The effect of reduc-... 

Ocean sequestration of CO2 by direct injection assumes that a relatively pure CO2 stream has been generated at a power plant or chemical factory and transported to an injection point. To better understand the role the ocean can play, we address the capacity of the ocean to sequester CO2, its effectiveness at reducing atmospheric CO2 levels, how to inject the CO2, and possible environmental consequences and issues of public perception. 

In practice the decomposition temperature must be exactly maintained. Thus one cannot employ a shorter reaction time at higher temperature without incurring a loss of activity in the material. The effect of the atmosphere in which the reaction proceeds is especially remarkable. In some cases it was possible to reduce the activation energies for the decomposition by 10-15 kcal./mole (by comparison with those needed in air or vacuum) by proper choice of the gaseous atmosphere. In many cases, a properly chosen gaseous atmosphere allows the decomposition to proceed at unusually low temperatures this in turn gives high active preparations [2]. 

A series of nine experiments was performed in the above manner, and nine experiments were made in order to eliminate the cooling or heating effects of the atmosphere. After reducing the result to the capacity for heat of a pound of water, it appeared that for each degree of heat evolved by the friction of water a mechanical power equal to that which can raise a weight of 8901b. to the height of one foot had been expended. 

The differences between Pitts (P) and Fuoss-Onsager (F-O) are first, the above mentioned omission by F-O of the effect of asymmetric potential on the local velocities of the solvent near the ions second, the use of the more usual boundary conditions 5.2.28b by F-O compared to the P assumption that perturbations cease to be important at r = a. Pitts, Tabor and Daly, who have analysed in detail both treatments, concluded that the discrepancy due to the different boundary conditions is small but has the effect of reducing ionic interactions in the P treatment with respect to the F-O. This is confirmed by the analysis of data with both theories. Usually P requires a smaller value of the a parameter than F-O. The third discrepancy between the theoretical treatments is in the expression of Vj, in eqn. 5.2.5, for which F-O add a term which involves the effect of the asymmetry of the ionic atmosphere upon the central ion surrounded by such atmosphere. The last difference lies in the hydrodynamic approaches and the corresponding boundary conditions. P imposes the condition that the velocity of the smoothed... 

However, the effect of reducing temperature is small if the value of Bj — B2 is small, as will be the case for two solvents of the same chemical class if their atmospheric pressure boiling points are close together. 

Evidence from terpenoid analyses of plant tissues support the observations of the effects of elevated atmospheric CO2 concentrations on volatile terpenoid emissions. Responses of stored monoterpenes and diterpenes in the needles of Scots pine and Norway spruce sapling to elevated CO2 were opposite when compared to temperature effect significantly reduced concentrations of many compounds have been detected [19]. Elevated CO2 had less influence on the concentrations of the stored monoterpenes and diterpenes in the stem bark, phloem and xylem. In Scots pines grown at elevated CO2 and elevated temperature environments in large closed-top-chambers, elevated CO2 resulted in consistently reduced total monoterpene concentration while temperature effects were more variable [20]. 

One gaseous pollutant that is of concern is NO2. Environmental concerns and regulations have had the effect of reducing the quantity of SO2 being emitted to the atmosphere. However, it is estimated that the emission of NO2 in these same areas over the past decade has shown a continuous increase. This was reported by RB Huser in Acid Deposition Long-Term Trends (National Academy Press, Washington, D.C., 1986, p 48). 

Swirl motions occurring in a water bath of aspect ratio ranging approximately from 0.2 to 1.0 were characterized by the starting time Ts,s, period Ts, amplitude A, and damping time Td,s. The effects of reduced pressure on the bath surface, Ps, on these quantities were experimentally investigated [41], The measured values of these quantities for gas injection under reduced pressure on the bath surface agreed favorably with their respective values for gas injection under atmospheric pressure condition on the bath surface provided that the volumetric gas flow rates at the nozzle tip, gg, were the same. Empirical relations were proposed for 7s,s, 7s,a, 7g, and. ... 

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