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Carle, G. C.

Publications and source records attributed to Carle, G. C..

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Sulfur trioxide in the lower atmosphere of Venus

Inconsistencies and ambiguities are noted by the present consideration of Pioneer Venus and Venera atmospheric composition measurement of Venus in the context of lower atmosphere thermodynamic equilibrium. Among the scenarios projected on the basis of assumed correctness for selected data subsets, the O2 and SO2 concentrations reported by the Pioneer Venus chromatograph and the H2O concentrations reported by Venera 11 suggest that large concentrations of SO3 are present in the lower atmosphere of Venus. Such SO3 concentrations lead, however, to difficulties in explaining the atmosphere at and above the cloud tops, and in addition require specific assumptions concerning chemical reaction rates at and near the surface.

Craig, R. A.↗
NASA NTRS1980

Pioneer Venus gas chromatography of the lower atmosphere of Venus

A gas chromatograph mounted in the Pioneer Venus sounder probe measured the chemical composition of the atmosphere of Venus at three altitudes. Ne, N2, O2, Ar, CO, H2O, SO2, and CO2 were measured, and upper limits set for H2, COS, H2S, CH4, Kr, N2O, C2H4, C2H6, and C3H8. Simulation studies have provided indirect evidence for sulfuric acid-like droplets and support the possibility of water vapor at altitudes of 42 and 24 km. The paper discusses the implications of these results for the origin, evolution, and present state of Venus' atmosphere.

Oyama, V. I.↗
NASA NTRS1980

Corrections in the Pioneer Venus sounder probe gas chromatographic analysis of the lower Venus atmosphere

Misidentification of two peaks from the Pioneer Venus sounder probe gas chromatograph (SPGC), also formerly known as the LGC, gave rise to quantitative errors in the abundances of oxygen, argon, and carbon monoxide. The argon abundance is estimated at 67 parts per million and that of carbon monoxide at 20 parts per million. At this time, no estimates for the oxygen abundance can be made.

Oyama, V. I.↗
NASA NTRS1980

Pioneer Venus Sounder Probe gas chromatograph

The design logic, construction, function, and data processing of the Pioneer Venus Sounder Probe gas chromatograph instrument are discussed. A gas chromatograph for the analysis of the chemical composition of the lower atmosphere of Venus was included in the Sounder Probe of the Pioneer Venus mission. This paper describes the design logic of the gas chromatograph as constrained by the mission; attention is given to instrument construction, function, and data reduction.

Oyama, V. I.↗
NASA NTRS1979

Laboratory corroboration of the Pioneer Venus gas chromatograph analyses

Laboratory simulation and tests of the inlet sampling system and columns of the Pioneer Venus gas chromatograph show that the sensitivity to argon is not diminished after the column regeneration step, that argon isotopes are not separated, that oxygen and sulfur dioxide are not produced in the inlet sampling system from sulfur trioxide, and that sulfur trioxide is not formed from sulfur dioxide and oxygen. Comparisons of the volatile inventory of Venus and earth imply similar efficiencies of early outgassing but a lower efficiency for later outgassing in the case of Venus. The high oxidation state of the Venus atmosphere in the region of cloud formation may prohibit the generation of elemental sulfur particles.

Oyama, V. I.↗
NASA NTRS1979

Venus lower atmospheric composition - Analysis by gas chromatography

The first gas chromatographic analysis of the lower atmosphere of Venus is reported. Three atmospheric samples were analyzed. The third of these samples showed carbon dioxide (96.4 percent), molecular nitrogen (3.41 percent), water vapor (0.135 percent), molecular oxygen (69.3 ppm), argon (18.6 ppm), neon (4.31 ppm), and sulfur dioxide (186 ppm). The amounts of water vapor and sulfur dioxide detected are roughly compatible with the requirements of greenhouse models of the high surface temperature of Venus. The large positive gradient of sulfur dioxide, molecular oxygen, and water vapor from the cloud tops to their bottoms, as implied by Earth-based observations and these results, gives added support for the presence of major quantities of aqueous sulfuric acid in the clouds. A comparison of the inventory of inert gases found in the atmospheres of Venus, Earth, and Mars suggests that these components are due to outgassing from the planetary interiors.

Oyama, V. I.↗
NASA NTRS1977

Preliminary findings of the Viking gas exchange experiment and a model for Martian surface chemistry

Earlier results reported from the Viking Lander-1 experiment are reexamined and interpreted in terms of a model of the Martian soil surface morphology and chemistry. Major events in the gas exchange experiment (GEX) first cycle are tabulated and data are presented on the sample processing and transport environments experienced by the soil samples. Oxygen and CO2 evolved from humidified Martian soil in GEX and slight changes in N2 present are investigated. A soil model involving iron oxide coating on silicate material is entertained to yield a mechanistic explanation of the experimental findings, and invocation of biotic processes is eschewed.

Oyama, V. I.↗
NASA NTRS1976

The search for life on Mars - Viking 1976 gas changes as indicators of biological activity

The objective of the gas exchange experiment (GEX) in the Viking lander biology instrument package is to determine whether life exists in a 1-cc Martian soil sample delivered to it. The GEX is capable of maximum flexibility while protecting the indigenous organisms from exposure to physiologically incompatible medium. The discussion covers the biological premises implemented in the GEX, the requirements for the GEX M4 medium, the operational aspects of the incubation chamber, nonbiological and biological changes, and Antarctica soil experiment. Sources of biological gas changes are examined along with ways of differentiating biological gas changes from nonbiological ones. From cold incubation of low-frequency soils, it is concluded that decisive negative tests of GEX may require extended incubations beyond the nominal mission plan of 60 days, barring any outright information that negates the presence of life on Mars.

Oyama, V. I.↗
NASA NTRS1974

The determination of soil moisture by extraction and gas chromatography

Soil moisture content was determined by extracting soil with methanol and subsequently analyzing the extract for water by gas chromatography. With air-dried mineral soils, this method gave slightly higher moisture content values than those obtained by the oven-dry method. Moisture content was determined quantitatively in soils to which various amounts of water had been added. The complete procedure, including extraction and analysis, requires less than one hour and gives results that closely compare to the oven-dry method.

Merek, E. L.↗
NASA NTRS1973

Soil moisture by extraction and gas chromatography

To determine moisture content of soils rapidly and conveniently extract moisture with methanol and determine water content of methanol extract by gas chromatography. Moisture content of sample is calculated from weight of water and methanol in aliquot and weight of methanol added to sample.

Merek, E. L.↗
NASA NTRS1972

Simple gas chromatographic system for analysis of microbial respiratory gases

Dual column ambient temperature system, consisting of pair of capillary columns, microbead thermistor detector and micro gas-sampling valve, is used in remote life-detection equipment for space experiments. Performance outweighs advantage gained by utilizing single-column systems to reduce weight, conserve carrier gas and operate at lower power levels.

Carle, G. C.↗
NASA NTRS1971

Automatic amino acid analyzer

Analyzer operates unattended or up to 15 hours. It has an automatic sample injection system and can be programmed. All fluid-flow valve switching is accomplished pneumatically from miniature three-way solenoid pilot valves.

Berdahl, B. J.↗