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The recycling of wastes from the biological complex for use in life-support systems is discussed. Topics include laboratory equipment, heat treatment of waste materials, mineralization of waste products, methods for production of ammonium hydroxide and nitric acid, the extraction of sodium chloride from mineralized products, and the recovery of nutrient substances for plants from urine.
Large area, semiconductor crystals selected from group 3-5 compounds and alloys are provided for semiconductor device fabrication by the use of a selective etching operation which completely removes the substrate on which the desired crystal was deposited. The substrate, selected from the same group as the single crystal, has a higher solution rate than the epitaxial single crystal which is essentially unaffected by the etching solution. The preparation of gallium phosphide single crystals using a gallium arsenide substrate and a concentrated nitric acid etching solution is described.
Data are presented from the 1977 Intertropical Convergence Zone (ITCZ) Experiment conducted in the Panama Canal Zone in July 1977. Measurements were made daily over a 16-day period when the ITCZ moved across the Canal Zone. Two aircraft (Learjet and U-2) flew daily and provided data from horizontal traverses at several altitudes to 21.3 km of ozone, temperature, pressure, water vapor, aerosols, fluorocarbons, methane, nitrous oxide, nitric oxide, and nitric acid. Balloonsondes flown four times per day provided data on ozone, wind fields, pressure, temperature, and humidities to altitudes near 30 km. Rocketsondes provided daily data to altitudes near 69 km. Satellite photography provided detailed cloud information. Descriptions of individual experiments and detailed compilations of all results are provided.
A review of the research in minor constituents in the stratosphere and mesosphere, carried out between 1975 and 1978, is presented. Much of the theoretical research was done with the aid of one-dimensional models. Different aspects of these models are discussed. Measurements of the chlorofluoromethanes, hydrochloric acid, nitric oxide, nitrous oxide, and hydrogen oxide were conducted. It is noted that the hydrogen oxides are now assuming a larger role in stratospheric photochemistry than have been postulated before. The effect of water vapor and the hydrogen oxides on the overall chemistry of the stratosphere was investigated theoretically, along with the possible relationship between solar activity and atmospheric ozone. The mesosphere study included ozone, water vapor, nitric oxide, and odd nitrogen investigations.
High resolution spectra in the region of the v(2) band of nitric acid have been obtained for selected portions of the HNO3 spectrum using tunable diode laser techniques. Continuous spectra are presented from 1718.97/cm to 1729.57/cm, with a spectral resolution not greater than 0.001/cm (30 MHz). Absolute line intensities and line positions are presented. Self- and foreign-gas (N2) broadening coefficients were iteratively calculated from the experimental data and were determined to be alpha(a) = 0.74/cm atm and alpha (f) = 0.13/cm atm, respectively.
The major eruption of Volcan de Fuego caused an enhancement of 1.6 x 10 to the 9 kg of SO4(-) in the stratosphere 6 months after the eruption. Measurable changes in nitric acid vapor and particulate chloride were not observed. Subsequent data suggests that HCl was not injected into the stratosphere. The first simultaneous measurement of halogen and sulfur content of gases and particles in explosive eruption plumes is reported. The average percents of elements in particles were sulfur, 2.5 + or - 2.1; chlorine, 18 + or - 12; and fluorine, 38 + or - 29. The average molecular ratio of HCl/SO2 and HCl/HF were 0.41 + or - 0.26 and 14 + or - 12 in the Guatemalan eruption plumes.
Stratospheric emission spectra in the submillimeter range have been recorded with a resolution of 0.0033/cm with a balloon-borne interferometer. Several minor atmospheric constituents have been identified in a preliminary analysis of the spectra; these are water vapor, oxygen, ozone isotopes, nitric acid, nitrous oxide, hydrofluoric and hydrochloric acids, and carbon monoxide.
Highlights of the year's activities and accomplishments are reported in the areas of aircraft safety, scientific ballooning, mid-air payload retrieval, and the design of a microwave power reception and conversion system for on use on a high altitude powered platform. The development and application of an agro-environmental system to provide crop management advisory information to Virginia farmers, and the radar tracking of insects are described. Aircraft systems, developed for measuring atmospheric ozone and nitric acid were used to sample emissions from Mount St. Helens. Investigations of the reliability and precision of the U.S. standard meteorological rocketsonde, applications of the microwave altimeter and airborne lidar system in oceanography, and the development of a multibeam altimeter concept are also summarized.
The efficiency of all treatment methods formerly or currently used in treating chemical wastes is assessed with emphasis on the disposal of hypergolic propellants. Maximum focus is on the space shuttle propellants MMH and N2O4. Except for hydrogen peroxide oxidizers, all the propellants are nitrogen based and can be potentially reduced to valuable plant nutrients. In theory, all the propellants can be reduced to carbon, hydrogen, nitrogen, and oxygen, except of fuming nitric acid which contains a small amount of fluorine. Appendices cover: (1) a general design criteria for disposal ponds; (2) thermal aspects of reaction in dilute solution; (3) gas bubble growth, detachment, and rise (4) absorption scrubber fundamentals and descriptions; (5) separation of a propellant vapor from a helium stream by permeation; and (6) atmospheric emission limits.
A bioluminescent assay for ATP in water borne bacteria is made by adding nitric acid to a water sample with concentrated bacteria to rupture the bacterial cells. The sample is diluted with sterile, deionized water, then mixed with a luciferase-luciferin mixture and the resulting light output of the bioluminescent reaction is measured and correlated with bacteria present. A standard and a blank also are presented so that the light output can be correlated to bacteria in the sample and system noise can be substracted from the readings. A chemiluminescent assay for iron porphyrins in water borne bacteria is made by adding luminol reagent to a water sample with concentrated bacteria and measuring the resulting light output of the chemiluminescent reaction.
Data are presented from the Stratospheric-Tropospheric Water Vapor Exchange Experiment. Measurements were made during 11 flights of the NASA U-2 aircraft which provided data from horizontal traverser and samplings in and about the tops of extensive cirrus-anvil clouds produced by overshooting cumulus turrets. Aircraft measurements were made of water vapor, ozone, ambient and cloud top temperature, fluorocarbons, nitrous oxide, nitric acid, aerosols, and ice crystal populations. Balloonsondes were flown about twice daily providing data on ozone, wind fields, pressure and temperature to altitudes near 30 km. Satellite photography provided detailed cloud and cloud top temperature information. Descriptions of individual experiments and detailed compilations of all results are provided.
While it is generally thought that the bactericidal effects of NO and NO2 derive from their reaction with water to form nitrous and nitric acids (Shank et al., 1962), this appears to be true only at high concentrations. The data presented here suggest that at low NO and NO2 concentrations, acids are not present in high enough concentrations to act as toxic agents. Reference is made to a study by Grant et al. (1979), which found that exposing acid forest soil to 1 ppm of NO2 did not cause the soil pH to drop. The results presented here show that at low concentrations of NO and NO2, the NO is bacteriostatic for some organisms and not for others, whereas NO2 may protect some bacteria from the inhibitory effects of NO. Since it has been shown that bacteria can divide while airborne (Dimmick et al., 1979), the present results suggest that NO at the low concentrations found in the atmosphere can select for resistant bacteria in the air and affect the viable airborne bacterial population.
An experiment and results, using a six-channel infrared radiometer aboard the Nimbus 7 spacecraft to sound the composition and structure of the middle atmosphere, are described. The measurement requirements are discussed, and critical instrument parameters are identified. Next, the instrument and its laboratory calibration are described. Temperature accuracy and precision are estimated to be 2 K and about 0.4 K respectively. Accuracy of the trace gas measurements is about 25 percent, comparable to the estimated accuracy of the in situ comparison data; their precision is about 0.25 ppmv for ozone and water vapor and 0.2 ppbv for nitric acid and nitrogen dioxide. Examples of the vertical profiles, maps, and cross sections of the data show previously unobserved variations with latitude, altitude, and time. The results demonstrate that infrared limb scanning is an extremely powerful method for sounding the middle atmosphere.
A time-dependent, one-dimensional photochemical model of the troposphere is used to describe the vertical distribution of atmospheric trace constituents for summer-time conditions at midlatitudes in the Northern Hemisphere. The model incorporates a planetary boundary layer (PBL) parametrization and a detailed chemical mechanism that includes the photochemistry of important nonmethane hydrocarbon species formed during the oxidation process. One result of the parametrized PBL is that the concentrations of some trace species in the free troposphere are 20-30 percent higher than when mixing processes are described by a vertical eddy diffusion coefficient which is held constant with respect to height and time. The lifetime of the oxides of nitrogen against photochemical conversion to nitric acid during summertime conditions is on the order of six hours. This lifetime is short enough to deplete most of the NO(x) in the PBL so that other reactive nitrogen species are more abundant than NO(x) throughout the free troposphere.
Methylhydrazinium nitrate was synthesized by the reaction of dilute nitric acid with methylhydrazine in water and in methanol. The white needles formed are extremely hygroscopic and melt at 37.5-40.5 C. The IR spectrum differs from that reported elsewhere. The mass spectrum exhibited no parent peak at 109 m/z, and thermogravimetric analysis indicated that the compound decomposed slowly at 63-103 C to give ammonium and methylammonium nitrate. The density is near 1.55 g/cu cm.
The purpose of the Nimbus 7 LIMS experiment was to sound the composition and structure of the upper atmosphere and provide data for study of photochemistry, radiation, and dynamics processes. Vertical profiles were measured of temperature and ozone (O3) over the 10-km to 65-km range and water vapor, nitrogen dioxide, and nitric acid over the 10-km to 50-km range. Latitude coverage extended from 64 deg S to 84 deg N. Several general features of the atmosphere have emerged from data analyzes thus far. Nitrogen dioxide exhibits rapid latitudinal variations in winter and shows hemispheric asymmetry with generally higher vertical column amount in the summer hemisphere. HNO3 data show that this gas is highly variable with altitude, latitude, and season. Smallest mixing ratios occur in the tropics, and the largest values occur in the high latitude winter hemisphere. The results show that O3, NO2, and HNO3 are strongly affected during a stratospheric warming.
Observations of medium-scale transient wave activity in the middle-latitude Southern Hemisphere summer stratosphere are interpreted using isentropic potential vorticity (IPV) distributions inferred from temperature data from the Nimbus-7 Limb Infrared Monitor of the Stratosphere (LIMS) instrument. Despite problems with errors in reference-level synoptic height information, the derived IPV distributions clearly exhibit dynamically coherent signatures of eddy mixing due to medium-scale disturbances in the lower-middle stratosphere during early January 1979. The IPV distributions are shown to be strongly correlated with those of a contemporaneous set of isentropic maps of quasi-conservative tracers such as ozone and nitric acid. The results suggest that IPV maps inferred from satellite temperature data provide a useful diagnostic for studies of large-scale dynamics and/or transport in the extratropical stratosphere. Furthermore, the comparatively high vertical resolution of the LIMS data has enabled the vertical attenuation of Southern Hemisphere wave activity to be diagnosed in greater detail than could be achieved from nadir-viewing satellite information.
Fluidized-bed chemical cleaning process developed to remove metallic impurities from small silicon particles. Particles (250 micrometer in size) utilized as seed material in silane pyrolysis process for production of 1-mm-size silicon. Product silicon (1 mm in size) used as raw material for fabrication of solar cells and other semiconductor devices. Principal cleaning step is wash in mixture of hydrochloric and nitric acids, leaching out metals and carrying them away as soluble chlorides. Particles fluidized by cleaning solution to assure good mixing and uniform wetting.