Search NASA⌕ Search

SEARCH · Search NASA

Results for “compositional data”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Comparison of two gas chromatograph models and analysis of binary data

The overall objective of the gas chromatograph system studies is to generate fundamental design criteria and techniques to be used in the optimum design of the system. The particular tasks currently being undertaken are the comparison of two mathematical models of the chromatograph and the analysis of binary system data. The predictions of two mathematical models, an equilibrium absorption model and a non-equilibrium absorption model exhibit the same weaknesses in their inability to predict chromatogram spreading for certain systems. The analysis of binary data using the equilibrium absorption model confirms that, for the systems considered, superposition of predicted single component behaviors is a first order representation of actual binary data. Composition effects produce non-idealities which limit the rigorous validity of superposition.

Keba, P. S.↗
NASA NTRS1971

Relationship between siderophilic-element content and oxidation state of ordinary chondrites.

The concentrations of Ni and Ir have been determined by neutron activation in a suite of ordinary chondrites for which accurate ferromagnesian-mineral compositional data were available. Although hiatus between the individual groups exist, the trends within the groups are in keeping with the hypothesis that the ordinary chondrites form a continuous fractionation sequence. A significant negative correlation is observed between the abundance of Ni or Ir and the Fe content of the ferromagnesian minerals in the H and L groups, and for Ir in the LL group, as expected if the metal-silicate fractionation and the variation in oxidation states were produced by the same or related processes. The Ir/Ni ratio decreases by a factor of 1.2 between the H and LL groups. This fractionation must have occurred at an early stage in the condensation phase of the solar nebula.

Mueller, O.↗
NASA NTRS1972

Distribution and significance of carbon compounds on the moon.

Exploration of available information concerning carbon on the moon, following review of what is known about carbon on the earth, and consideration of the results of studies of meteorites, which have provided the first direct clues about extraterrestrial carbon. Carbon and carbon isotope composition data taken from Apollo 11 samples are tabulated. Carbon compounds produced by pyrolysis, extracted with benzene-methanol, extracted with water, and freed by acid treatment are discussed. Carbon and carbon compounds in lunar rocks and soils appear to be distributed heterogeneously.

Chang, S.↗
NASA NTRS1971

Chemical evidence relating to the origin of the returned lunar material.

The material returned on the Apollo 11 mission can be separated into four types on chemical as well as structural grounds. Two distinct crystalline rock types can be identified, which may have been formed during two separate magmatic events. The lunar soil and breccias (which are apparently impacted soil material) can be thought of as being composed of a crystalline rock component similar in composition to, but differing in detail from, the two types of Apollo 11 crystalline rocks, and anorthositic component amounting to about 20% in the lunar soil, and a meteoritic component resembling carbonaceous chondrites in composition. Data on Ga, Ge, In, Ir, and Au in Apollo 11 rocks reflect the high temperature history of the lunar surface material, and the presence of a meteoritic component in the soil and breccias.

Baedecker, P. A.↗
NASA NTRS1973

Fatigue of boron-aluminum composites bonds and joints

Study examines effects of boron filament diameter on bonds and joints in boron-aluminum composite. Data include static strength, fatigue, and dynamic moduli of elasticity. Manson-Coffin analyses and metallurgical and fracture surface evaluation were also performed.

Hersh, M. S.↗
NASA NTRS1973

Equatorial thermospheric composition and its variations.

The neutral atmospheric composition experiment on the San Marco 3 satellite has measured the composition of the equatorial atmosphere from Apr. 29 to Nov. 29, 1971. Preliminary results on the diurnal variation of atmospheric composition from May 19 to June 30 at 225 km altitude are presented. The diurnal variation of helium is seen to reach its maximum near 0800 hours and its minimum in the late afternoon, in contrast to the behavior of molecular nitrogen and argon. The atomic oxygen densities show smaller variations than those of the other gases. The mass densities calculated from the composition data agree well with those determined from the in situ drag force measurements and from orbital decay measurements.

Newton, G. P.↗
NASA NTRS1973

Effects of gravity on ontogeny in animals.

Inversion or clinostat rotation of frogs' eggs demonstrated a critical period of enhanced gravity-sensitivity prior to the first cleavage. These results were corroborated by centrifugation studies which localized the period of maximal sensitivity at approximately 20 minutes post-fertilization. Eggs of various invertebrates suspended in aqueous solution proved capable of normal development following brief ultracentrifugation. Among fly larvae, grasshopper nymphs, turtles, mice, rats, and chickens, growth rates were inversely related to G-force, and maximal chronic acceleration tolerated was inversely related to body size. Body composition data demonstrated the importance of separately evaluating fat and the fat-free portion of the body in studies of the effect of acceleration on growth in homeotherms. The attempt to evaluate the effect of weightlessness on the development of frogs' eggs in Biosatellite 2 was inconclusive for technical reasons.

Pitts, G. C.↗
NASA NTRS1974

Argon: A thermometer of the upper atmosphere

The exospheric temperatures are derived from Ar, N2, O and He measurements obtained from the Aeros-1 NATE experiment. It is shown that the temperatures derived from Ar and N2 are very close to each other and show very similar seasonal, latitudinal and the day to night variations both under quiet and the geomagnetically disturbed conditions. The temperatures derived from O and He do not usually follow this pattern because of their large variabilities in the lower thermosphere. The differences in the inferred temperatures from these gases are particularly noticeable when the neutral composition data between 220-250 km are used. In this altitude region Ar appears to have some advantage over N2 for the purpose of deriving neutral temperature.

Chandra, S.↗
NASA NTRS1973

Crystallization history of metal particles in Apollo 16 rake samples

Electron microprobe analyses for Fe, Co, Ni, S, and P have been carried out on the metal and associated troilite, schreibersite, and rare cohenite in the Apollo 16 rake samples from Stations 1, 4, and 13. The Co/Ni ratios of most of the metal are within the limits of meteoritic metal as defined by Goldstein and Yakowitz (1971). The large abundance of schreibersite in all of the lithic types except the poikilitic rocks suggests that much of it may be of lunar origin. The near-absence of schreibersite in the poikilitic rocks may be a result of P diffusion from the metal to the surrounding silicate at low temperature. Application of the compositional data for the coexisting metal-schreibersite pairs to isotherms in the system Fe-Ni-P indicates a sequence of progressively lower temperatures of equilibration (and probably a corresponding sequence of slower cooling rates) of these phases from the devitrified glasses, to the mesostasis-rich rocks, to the diabases, to the poikilitic rocks.

Gooley, R. C.↗
NASA NTRS1974

High latitude minor ion enhancements - A clue for studies of magnetosphere-atmosphere coupling

An investigation is conducted of upper ionosphere molecular ion composition data, which because of the unexpected, abrupt enhancements sometimes exhibited at high latitudes, may indirectly offer additional clues to understanding the processes by which the lower atmosphere becomes perturbed. It is found that molecular ion irregularities are sometimes localized in a relatively narrow region of time and space. The abruptness of these events suggests that lower atmosphere energetic processes presumed responsible for the ion enhancements may also be narrowly distributed.

Taylor, H. A., Jr.↗
NASA NTRS1975

A fast sampling device for the mass spectrometric analysis of liquid rocket engine exhaust

The design of a device to obtain compositional data on rocket exhaust by direct sampling of reactive flow exhausts into a mass spectrometer is presented. Sampling at three stages differing in pressure and orifice angle and diameter is possible. Results of calibration with pure gases and gas mixtures are erratic and of unknown accuracy for H2, limiting the usefulness of the apparatus for determining oxidizer/fuel ratios from combustion product analysis. Deposition effects are discussed, and data obtained from rocket exhaust spectra are analyzed to give O/F ratios and mixture ratio distribution. The O/F ratio determined spectrometrically is insufficiently accurate for quantitative comparison with cold flow data. However, a criterion for operating conditions with improved mixing of fuel and oxidizer which is consistent with cold flow results may be obtained by inspection of contour plots. A chemical inefficiency in the combustion process when oxidizer is in excess is observed from reactive flow measurements. Present results were obtained with N2O4/N2H4 propellants.

Ryason, P. R.↗
NASA NTRS1975

Pyroxenes in the Patwar mesosiderite

Major and minor elements were determined with an electron microprobe in pyroxene from Patwar, one of the least metamorphosed mesosiderites. All but two orthopyroxene crystal fragments fall in the range Wo(2.3)En(73) to Wo(3.9)En(59), while pigeonite from a basalt clast clusters around Wo(13)En(38). Absolute and relative amounts of Ti, Cr, and Al are distinct from those in pyroxenes in irons-with-silicate inclusions. Zoning within orthopyroxene grains suggests crystallization from an igneous melt in the presence of plagioclase and chromite, followed at some later time by brecciation and subsequent minor thermal metamorphism. Compositional data support petrographic evidence that the silicates in Patwar were derived from a heterogeneous source.

Weigand, P. W.↗
NASA NTRS1977

Investigation of the agricultural resources in Sri Lanka

The author has identified the following significant results. Several in-house capabilities were developed. The facilities to prepare color composites of excellent quality were developed, using bulk B/W 70 mm transparencies or 1:1,000,000 positive transparencies. These color composites were studied through optical devices on light tables. A zoom transfer scope was also added, enabling direct transfer of LANDSAT composite data on to base maps.

Silva, A. T. M.↗
NASA NTRS1977

Description and review of global measurements of atmospheric species from GASP

Aerosol composition data were collected with a NASA F-106 aircraft. Present measurements include ozone, carbon monoxide, water vapor, aerosol and condensation nuclei number densities, sulphates, nitrates, and the chlorofluoromethanes. Meteorological and flight parameters are also recorded for use in data analysis. The present aircraft operations obtain data between 6 and 13.5 km from 65 degree N between Europe and the north Pacific, and from 23 degree S over South America and 42 degree S over New Zealand. Typical constituent data from the aircraft operations during the first one and a half years are presented. Instrumentation is discussed.

Gauntner, D. J.↗
NASA NTRS1976

Geomagnetic storm effects on the thermosphere and the ionosphere revealed by in situ measurements from OGO 6

The temporal response of the densities of upper-atmospheric ion and neutral constituents to a particular geomagnetic storm is studied using simultaneous ion and neutral-composition data obtained by the OGO 6 satellite during consecutive orbits at altitudes greater than 400 km. The investigated constituents include H(+), O(+), N2, O, He, and H. Derivation of the H density is reviewed, and the main effects of the storm are discussed, particularly temporal and global variations in the densities. It is found that: (1) the H and He densities began to decrease near the time of sudden commencement, with the decrease amounting to more than 40% of the quiet-time densities during the maximum stage at high latitudes; (2) the O and N2 densities exhibited an overall increase which began later than the change in H and He densities; (3) the H(+) density decreased differently in two distinct regions separated near the low-latitude boundary of the light-ion trough; and (4) the O(+) density showed an increase during earlier stages of the storm and decreased only in the Northern Hemisphere during the recovery phase. Certain physical and chemical processes are suggested which play principal roles in the ionospheric response to the storm

Marubashi, K.↗
NASA NTRS1977

The effects of thermospheric winds and chemistry in the diurnal variations of thermospheric species

The reported investigation considers on the basis of a theoretical model, the diurnal variations of the thermospheric composition (H, He, O, O2, and Ar) in terms of thermal expansion with diffusive equilibrium and transport effects associated with thermospheric winds, chemistry, and exospheric flow. The theoretical results are compared with satellite composition data which indicate that the fundamental diurnal tide can be reasonably well understood. It is found that winds are only important for molecular oxygen below 180 km, while thermal expansion due to the larger mass is relatively more important for O2 than for O. Distinct from O, photodissociation and in particular photoionization of O2 are very significant for molecular oxygen.

Mayr, H. G.↗
NASA NTRS1978

The signature of H/+/ in the equatorial anomaly - An empirical model

Ion composition data from the OGO-6 satellite are used to develop an empirical model of the H(+) signature in the equatorial anomaly. The empirical model is an attempt to represent the generally repeatable details of the satellite data by a parameterized numerical model accounting for such variables as the altitude, local time and longitude of the observations. Although the resulting model is in general agreement with past findings on the variability of the equatorial anomaly phenomenon, there appears to be a complexity of short-term or narrowly localized variations which cannot be adequately understood on the basis of data from a single satellite.

Taylor, H. A., Jr.↗
NASA NTRS1979

Auroral origin of medium scale gravity waves in neutral composition and temperature

The kinetic temperature and neutral composition data obtained from the Aeros B neutral atmosphere temperature experiment and the neutral and ion mass spectrometer show spatial structures characteristic of medium scale gravity waves with a wavelength in the range of several hundred kilometers. These waves are associated with auroral activity, and their spatial structure reflects the time history of the auroral electrojet. The medium scale gravity waves tend to propagate to mid-latitudes on the nightside. On the dayside their range is limited to high latitudes. Gravity waves are carriers of auroral energy to middle and low latitudes where they may cause irreversible changes in temperature via viscous dissipation. Since auroral activity occurs frequently, it is suggested that this energy reaches the mid-latitude region of the thermosphere much more frequently than is indicated by planetary magnetic indices.

Chandra, S.↗