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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS1989

Electrochemical incineration of wastes

A low temperature electrolysis process has been developed for the treatment of solid waste material and urine. Experiments are described in which organic materials are oxidized directly at the surface of an electrode. Also, hypochlorite is generated electrochemically from chloride component of urine. Hypochlorite can act as a strong oxidizing agent in solution. The oxidation takes place at 30-60 C and the gaseous products from the anodic reaction are carbon dioxide, nitrogen, oxygen. Hydrogen is formed at the cathode. Carbon monoxide, and nitrogen oxides and methane were not detected in the off gases. Chlorine was evolved at the anode in relatively low amounts.

Kaba, L.↗
NASA NTRS1989

The Stratospheric Aerosol and Gas Experiment III instrument proposed for EOS - A conceptual design

This paper describes the Stratospheric Aerosol and Gas Experiment III (SAGE III) instrument proposed for the Earth Observing System (EOS), which is designed to monitor the vertical distribution of stratospheric aerosols, ozone, water vapor, nitrogen dioxide, and temperature by measuring the extinction and scattering of solar radiation in the 03 to 1.6 micron range through the atmosphere. The SAGE III employs proven concepts which have evolved from the SAM II, SAGE, and SAGE II programs. The launch is scheduled for the summer of 1996. The SAGE II block diagram is included.

Mauldin, L. E.↗
NASA NTRS1990

Kelvin wave-induced trace constituent oscillations in the equatorial stratosphere

Kelvin wave induced oscillations in ozone (O3), water vapor (H2O), nitric acid (HNO3) and nitrogen dioxide (NO2) in the equatorial stratosphere are analyzed using Limb Infrared Monitor of the Stratosphere (LIMS) data. Power and cross-spectrum analyses reveal coherent eastward propagating zonal wave 1 and 2 constituent fluctuations, due to the influence of Kelvin waves previously documented in the LIMS data. Comparison is made between a preliminary and the archival versions of the LIMS data; significant differences are found, demonstrating the sensitivity of constituent retrievals to derived temperature profiles. Because Kelvin waves have vanishing meridional velocity, analysis of tracer transport in the meridional plane is substantially simplified. Kelvin wave vertical advection is demonstrated by coherent, in-phase temperature-tracer oscillations, co-located near regions of strong background vertical gradients.

Randel, William J.↗
NASA NTRS1991

SAGE III capabilities and global change

The science objectives of the satellite-borne SAGE III are presented as they pertain to detecting global change. SAGE III is the proposed follow on and improved version of SAM II, SAGE I and SAGE II which have measured stratospheric and, in some cases, tropospheric species since late 1978. Specifically, SAGE III will measure profiles of aerosols, ozone, water vapor, nitrogen dioxide and trioxide, neutral density, temperature, clouds, and chlorine dioxide using the solar and lunar occultation techniques. These techniques are inherently self-calibrating, provide high vertical resolution, and use well-behaved data retrievals making them ideal for trend detection and global change studies. The potential capabilities of SAGE III are illustrated by using data and results from SAM II, SAGE I and SAGE II.

Mccormick, M. Patrick↗
NASA NTRS1992

SAGE II stratospheric density and temperature retrieval experiment

This paper describes a stratospheric density and temperature retrieval experiment based on the solar occultation measurement of the Stratospheric Aerosol and Gas Experiment (SAGE II). The entire retrieval analysis involves two inversion steps: the vertical structure inversion, which derives the profile of local atmospheric extinction from SAGE II limb optical depth data, and the species inversion, which inverts the concentration of air molecules, aerosols, ozone, and nitrogen dioxide from the derived atmospheric extinction at five SAGE II short wavelengths (0.385, 0.448, 0.453, 0.525, and 0.600 microns). The derived density profile is then used to infer the temperature distribution, assuming that the atmosphere is in hydrostatic equilibrium and obeys the ideal gas law. The temperature profiles retrieved from the SAGE II observations are compared with near-coincident, in both time and space, French Rayleigh lidar and NASA Wallops Flight Facility rocket datasonde soundings as well as the National Meteorological Center (NMC) data analyses. The results indicate that the mean SAGE II temperature agrees with the mean lidar measurements to within 2 C at altitudes from 30.5 to 52.5 km. The SAGE II and datasonde observations agree to within about 4 C in approximately the same altitude region.

Wang, Pi-Huan↗
NASA NTRS1991

Improved Limb Atmospheric Spectrometer (ILAS) for polar stratospheric trace gas measurements

The Improved Limb Atmospheric Spectrometer (ILAS) is a grating spectrometer designed to measure vertical profiles of high latitude stratospheric constituents in a solar occultation mode. ILAS measurement gases are ozone (03), methane (CH4), nitrous oxide (N2O), nitric acid (HNO3), water vapor (H2O), nitrogen dioxide (NO2), and CFC-11 using an IR channel. Temperature, pressure, and aerosol are also measured using a visible channel. The IR channel consists of 44 detector elements which cover the spectral range 6.2 to 11.8 microns, and the visible channel is composed of 1024 pixels that cover 753 to 784 nm. ILAS will be installed on the Advanced Earth Observing Satellite (ADEOS) which will be launched in 1995. Instrument design data are outlined.

Yokota, Tatsuya↗
NASA NTRS1992

Effect of inert propellant injection on Mars ascent vehicle performance

A Mars ascent vehicle is limited in performance by the propellant which can be brought from Earth. In some cases the vehicle performance can be improved by injecting inert gas into the engine, if the inert gas is available as an in-situ resource and does not have to be brought from Earth. Carbon dioxide, nitrogen, and argon are constituents of the Martian atmosphere which could be separated by compressing the atmosphere, without any chemical processing step. The effect of inert gas injection on rocket engine performance was analyzed with a numerical combustion code that calculated chemical equilibrium for engines of varying combustion chamber pressure, expansion ratio, oxidizer/fuel ratio, and inert injection fraction. Results of this analysis were applied to several candidate missions to determine how the required mass of return propellant needed in low Earth orbit could be decreased using inert propellant injection.

Colvin, James E.↗
NASA NTRS1993

A global analysis of the ozone deficit in the upper stratosphere and lower mesosphere

The global measurements of temperature, ozone, water vapor, and nitrogen dioxide acquired by the Limb Infrared Monitor of the Stratosphere (LIMS), supplemented by a precomputed distribution of chlorine monoxide, are used to test the balance between odd oxygen production and loss in the upper stratosphere and lower mesosphere. An efficient photochemical equilibrium model, whose validity is ascertained by comparison with the results from a fully time-dependent one-dimensional model at selected latitudes, is used in the calculations. The computed ozone abundances are systematically lower than observations for May 1-7, 1979, which suggests, contrary to the conclusions of other recent studies, a real problem in model simulations of stratospheric ozone.

Eluszkiewicz, Janusz↗
NASA NTRS1954

Investigation of effect of fluoride on corrosion of 2S-0 aluminum and 347 stainless steel in fuming nitric acid at 170 F

The effect of small additions of fluoride on the corrosion of 2S-0 aluminum and 347 stainless steel by fuming nitric acid at 170 degrees F has been evaluated quantitatively by the determination of the weight loss of metal specimens immersed in the acid. The ratio of metal surface area to volume of acid was approximately 7.5 inch (superscript)-1 in all cases. It was found that for acids containing no fluorides the weight loss of aluminum was approximately 1/5 that of stainless steel. Addition of 1 percent fluoride ion to the acid reduced the weight loss of both metals to practically zero even after 26 days of exposure to the acid at 170 degrees F. The minimum quantity of fluoride ion required to inhibit corrosion was found to be approximately 0.25 and 0.5 percent for aluminum and stainless steel, respectively, in white fuming nitric acid and 0.5 and 1 percent in red fuming nitric acid (18 percent nitrogen dioxide). These fluoride percentages were based on the total weight of acid. Provided the concentration of fluoride ion was sufficient to inhibit corrosion, the source of these ions was immaterial. Additional information concerning the effect of fluorides on corrosion was obtained by measuring the electrode potentials of the metals against a platinum reference electrode.

Feiler, Charles E↗
NASA NTRS1993

The seasonal evolution of reactive chlorine in the Northern Hemisphere stratosphere

In situ measurements of chlorine monoxide (ClO) at mid- and high northern latitudes are reported for the period October 1991 to February 1992. As early as mid-December and throughout the winter, significant enhancements of this ozone-destroying radical were observed within the polar vortex shortly after temperatures dropped below 195 K. Decreases in ClO observed in February were consistent with the rapid formation of chlorine nitrate (ClONO2) by recombination of ClO with nitrogen dioxide (NO2) released photochemically from nitric acid (HNO3). Outside the vortex, ClO abundances were higher than in previous years as a result of NO(x) suppression by heterogeneous reactions on sulfate aerosols enhanced by the eruption of Mount Pinatubo.

Toohey, D. W.↗
NASA NTRS1994

Annual variability of ozone along alpine hillsides

Over a period of more than two years (March 1989 till June 1991) ozone and nitrogen dioxide have been monitored along twelve alpine hillsides in the Austrian alps. The profiles had a height-resolution of 100 m and cover a range between 400 m and 1800 m asl, that is 100 m to 1100 m above the bottom of the valleys. They were situated in remote rural areas as well as in the vicinity of polluted urban and industrial areas. Both trace gases were monitored by means of integral chemical (SAM-surface active monitor) methods with a measuring cycle of two weeks. The concentration of ozone exhibits a substantial annual variation over the entire height range. In summer, highest ozone levels are observed near the ground and at the top of the mountains, whereas in winter the maxima are found mainly in the crest regions. The overall ozone burden shows a relative maximum near the temperature inversion layer in the valleys and an absolute maximum at the crest.

Putz, Erich↗
NASA NTRS1994

Measurements of stratospheric NO, NO2, and N2O5 by ISAMS: Preliminary observations and data validation

The Improved Stratospheric and Mesospheric Sounder (ISAMS) is a multichannel radiometer and forms part of the science payload of the Upper Atmosphere Research Satellite (UARS). ISAMS measures infrared emissions from the Earth's atmosphere in several wavelength bands. Three such bands include emission from nitric oxide, nitrogen dioxide, and dinitrogen pentoxide. In this paper, we briefly discuss how the ISAMS instrument measures NO, NO2, and N2O5. We also present preliminary data from these channels and describe preliminary validation work.

Kerridge, Brian J.↗
NASA NTRS1994

NO2 column changes induced by volcanic eruptions

Nitrogen dioxide slant column amounts measured by ground-based remote sensing from Lauder, New Zealand (45 deg S) and Campbell Island (53 deg S) during the second half of 1991 and early 1992 show anomalously low values that are attributed to the effects of volcanic eruptions. It is believed that the eruptions of Mount Pinatubo in the Philippines in June 1991 and possibly Mount Hudson in Chile in August 1991 are responsible for the stratospheric changes, which first became apparent in July 1991. The effects in the spring of 1991 are manifested as a reduction in the retrieved NO2 column amounts from normal levels by 35 to 45 percent, and an accompanying increase in the overnight decay of NO2. The existence of an accurate long-term record of column NO2 from the Lauder site enables us to quantify departures from the normal seasonal behavior with some confidence. Simultaneous retrievals of column ozone agree well with Dobson measurements, confirming that only part of the NO2 changes can be attributed to a modification of the scattering geometry by volcanic aerosols. Other reasons for the observed behavior are explored, including the effects of stratospheric temperature increases resulting from the aerosol loading and the possible involvement of heterogeneous chemical processes.

Johnston, Paul V.↗
NASA NTRS1994

SPEAM-II experiment for the measurement of stratospheric NO2, O3 and aerosols

Following the success of the Sunphotometer Earth Atmosphere Measurement (SPEAM-I) experiment, a more involved experiment was developed to fly as part of the second set of Canadian Experiments (CANEX-2) which will fly on the US Space Shuttle in the fall of 1992. The instrument complement includes an IBM-PC compatible control computer, a hand-held diode array spectrophotometer, and an interference-filter, limb imaging radiometer for the measurement of the atmospheric airglow. The hand-held spectrometer will measure nitrogen dioxide, ozone and aerosols. The limb imaging radiometer will observe emissions from the O2(1 DELTA) and O2(1 SIGMA) airglow bands. Only the spectrophotometer will be discussed here.

Mcelroy, C. T.↗
NASA NTRS1993

Observations of the loss of stratospheric NO2 following volcanic eruptions

Observations of stratospheric column amounts of nitrogen dioxide (NO2), nitric oxide (NO) and nitric acid (HNO3) have been made following major eruptions of the El Chichon and Mt. Pintatubo volcanoes. Midlatitude abundances of NO2 and NO were reduced by as much as 70% in the months following the appearance of the volcanic aerosols as compared to volcanically quite periods. There are heterogeneous reactions which could occur on the volcanic aerosols to convert NO2 into HNO3 but no commensurate increase in HNO3 column amounts was observed at the times of NO2 decrease.

Coffey, M. T.↗
NASA NTRS1994

Evolution of the martian atmosphere

Carbon dioxide, nitrogen, and the nonradiogenic and radiogenic noble gases are tracked from primordial inventories to their present states in a revised model of atmospheric evolution on Mars. Elemental and isotopic abundances evolve by hydrodynamic escape, impact erosion, outgassing, sputtering, photochemical escape of nitrogen, and carbonate formation and recycling. Atmospheric history is divided into early and late evolutionary periods, the first characterized by high CO2 pressures and a possible greenhouse and the second by a low pressure cap-regolith buffered system initiated by polar CO2 condensation approximately 3.7 Gyr ago. During early evolution the Xe isotopes are fractionated to their present composition by hydraulic escape, and CO2 pressure and isotopic history are dictated by the interplay of losses to erosion, sputtering, and carbonate precipitation, additions by outgassing and carbonate recycling, and perhaps also by feedback stabilization under greenhouse conditions. Atmospheric collapse near 3.7 Gyr leads to abrupt increases in the mixing ratios of preexisting Ar, Ne, and N2 at the exobase and their rapid removal by sputtering. Current abundances and isotopic compositions of these light species are therefore entirely determined by the action of sputtering and photochemical escape on gases supplied by outgassing during the late evolutionary epoch. The present atmospheric Kr inventory also derives almost completely from solar-like Kr degassed during this period. Consequently, among current observables, only the Xe isotopes and delta(C-13) survive as isotopic tracers of atmospheric history prior to its transition to low pressure.

Pepin, Robert O.↗
NASA NTRS1995

Subminiaturization for ERAST instrumentation (Environmental Research Aircraft and Sensor Technology)

We are focusing on the Argus as an example to demonstrate our philosophy on miniaturization of airborne analytical instruments for the study of atmospheric chemistry. Argus is a two channel, tunable-diode laser absorption spectrometer developed at NASA for the measurement of nitrogen dioxide (N2O) (4.5 micrometers) and ammonia (CH3) (3.3 micrometers) at the 0.1 parts per billion (ppb) level from the Perseus aircraft platform at altitudes up to 30 km. Although Argus' mass is down to 23 kg from the 197 kg Atlas, its predecessor, our goal is to design a next-generation subminiaturized instrument weighing less than 1 kg, measuring a few cm(exp 3) and able to eliminate dewars for cooling. Current designs enable use to make a small,inexpensive, monolithic spectrometer without the required sensitivity range. Further work is on its way to increase sensitivity. We are continuing to zero-base the technical approach in terms of the specifications for the given instrument. We are establishing a check list of questions to hone into the best micromachining approach and to superpose on the answers insights in scaling laws and flexible engineering designs to enable more relaxed tolerances for the smallest of the components.

Madou, Marc↗
NASA NTRS1998

Evaluation of Portable Multi-Gas Analyzers for use by Safety Personnel

During confined space entry operations as well as Shuttle-safing operations, United Space Alliance (USA)/National Aeronautics and Space Administration (NASA) safety personnel use a variety of portable instrumentation to monitor for hazardous levels of compounds such as nitrogen dioxide (N%), monomethylhydrazine (NMM), FREON 21, ammonia (NH3), oxygen (O2), and combustibles (as hydrogen (H2)). Except for O2 and H2, each compound is monitored using a single analyzer. In many cases these analyzers are 5 to 10 years old and require frequent maintenance. In addition, they are cumbersome to carry and tend to make the job of personnel monitoring physically taxing. As part of an effort to upgrade the sensor technology background information was requested from a total of 27 manufacturers of portable multi-gas instruments. A set of criteria was established to determine which vendors would be selected for laboratory evaluation. These criteria were based on requests made by USA/NASA Safety personnel in order to meet requirements within their respective areas for confined-space and Shuttle-safing operations. Each of the 27 manufacturers of multi-gas analyzers was sent a copy of the criteria and asked to fill in the appropriate information pertaining to their instrumentation. Based on the results of the sensor criteria worksheets, a total of 9 vendors out of 27 surveyed manufacturers were chosen for evaluation. Each vendor included in the final evaluation process was requested to configure each of two analyzers with NO2, NH3, O2, and combustible sensors. A set of lab tests was designed in order to determine which of the multi-gas instruments under evaluation was best suited for use in both shuttle and confined space operations. These tests included linearity/repeatability, zero/span drift response/recovery, humidity, interference, and maintenance. At the conclusion of lab testing three vendors were selected for additional field testing. Based on the results of both the lab and field evaluations a single vendor was recommended for use by NASA/IJSA Safety personnel. Vendor selection criteria, as well as the results from both laboratory and field testing of the multi-gas analyzers, are presented as part of this paper.

Lueck, D. E.↗