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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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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Chemical composition of Apollo 15, 16, and 17 samples

The authors analyzed 22 Apollo 15 samples, 21 Apollo 16 samples, 4 Luna 20 samples, and 6 Apollo 17 samples for 26 to 30 major, minor, and trace elements by instrumental neutron activation analysis (INAA). Major attention is given to Apollo 16 results and recent Apollo 17 data. The roster of elements via INAA has been extended to include Nd, Ni, Ir, and Au in the Apollo 16 and 17 samples. The latter three elements are highly abundant in these samples. Sample preparation, activation conditions, and the detailed INAA analytical procedure are essentially the same as reported by Laul and Schmitt (1973).

Laul, J. C.↗
NASA NTRS1975

Elemental composition of suspended particulates as functions of space and time in Cleveland, Ohio

An approach to the analysis of a very large elemental concentration data set. The particular data considered was generated by instrumental neutron activation and emission spectroscopy analyses of over 750 24-hour ambient air particulate samples collected at 16 sites in Cleveland, Ohio, during the 15 months from August 1971 thru October 1972. Examples are presented that show the use of multiple approaches to interpreting the data, including pairwise correlation statistics, selective data plotting and cluster analysis.

Neustadter, H. E.↗
NASA NTRS1975

Air pollution source identification

The techniques available for source identification are reviewed: remote sensing, injected tracers, and pollutants themselves as tracers. The use of the large number of trace elements in the ambient airborne particulate matter as a practical means of identifying sources is discussed. Trace constituents are determined by sensitive, inexpensive, nondestructive, multielement analytical methods such as instrumental neutron activation and charged particle X-ray fluorescence. The application to a large data set of pairwise correlation, the more advanced pattern recognition-cluster analysis approach with and without training sets, enrichment factors, and pollutant concentration rose displays for each element is described. It is shown that elemental constituents are related to specific source types: earth crustal, automotive, metallurgical, and more specific industries. A field-ready source identification system based on time and wind direction resolved sampling is described.

Fordyce, J. S.↗
NASA NTRS1974

Chemical studies of Apollo 16 and 17 samples

Instrumental neutron activation analyses were conducted to nine Apollo 16 samples and 23 Apollo 17 samples. Radiochemical neutron activation analyses were carried out in the case of six Apollo 16 boulder-2 rocks, five Apollo 17 soils, and one Apollo 16 soil. The elemental abundances obtained are presented in tables and the significance of the analytical results is discussed. Attention is also given to interelement correlations.

Laul, J. C.↗
NASA NTRS1975

Estimate of contribution of jet aircraft operations to trace element concentration at or near airports

Samples of ASTM type A jet fuel were analyzed for trace element content by instrumental neutron activation techniques. Forty-nine elements were sought. Only ten, aluminum, gold, indium, lanthanum, titanium, vanadium, barium, dysprosium, tellurium, and uranium, were observed at levels above the detection limits encountered; of these only aluminum, titanium, and barium were present at concentrations greater than 0.1 ppm. Estimates of exhaust gas concentrations are made, and the ambient contribution at or near airports is calculated by using the Los Angeles International Airport dispersion model. It is shown that the ambient contribution is about an order of magnitude below typical urban levels for virtually all elements sought.

Fordyce, J. S.↗
NASA NTRS1975

Water resources, chapter 2, part B

Various applications and projected applications of active microwave instruments for studying water resources. Most applications involve use of an imaging system operating primarily at wavelengths of less than 30 cm (i.e., K-, X-, and L-bands). Discussion is also included concerning longer wavelength nonimaging systems for use in sounding polar glaciers and icecaps (e.g., Greenland and the Antarctic). The section is divided into six topics: (1) stream runoff, drainage basin analysis, and floods, (2) lake detection and fluctuating levels, (3) coastal processes and wetlands, (4) seasonally and permanently frozen (permafrost) ground, (5) solid water resources (snow, ice, and glaciers), and (6) water pollution.

Source record↗
NASA NTRS1976

Extensive 1-year survey of trace elements and compounds in the airborne suspended particulate matter in Cleveland, Ohio

Concentrations of 75 chemical constituents in the airborne particulate matter were measured in Cleveland, Ohio, during 1971 and 1972. Values covering a 1-year period (45 to 50 sampling days) at each of 16 sites are presented for 60 elements. A lesser number of values is given for sulfate, nitrate, fluoride, acidity, 10 polynuclear aromatic hydrocarbon compounds, and the aliphatic hydrocarbon compounds as a group. Methods used included instrumental neutron activation, emission spectroscopy, gas chromatography, combustion techniques, and colorimetry. Uncertainties in the concentrations associated with the sampling procedures, the analysis methods, the use of several analytical facilities, and samples with concentrations below the detection limits are evaluated in detail. The data is discussed in relation to other studies and source origins. The trace constituent concentrations as a function of wind direction are used to suggest a practical method for air pollution source identification.

King, R. B.↗
NASA NTRS1977

High-pressure high-temperature transducer

Compact instrument has active and reference sides consisting of tubes that elongate in response to increasing interior pressures. Relative displacement of tubes is measured by linear variable differential transformer to determine pressure on active side. Device needs no internal cooling, thus eliminating condensation problem with gases containing saturated steam.

Vrolyk, J. J.↗
NASA NTRS1976

Biomedical technology transfer: Bioinstrumentation for cardiology, neurology, and the circulatory system

Developments in applying aerospace medical technology to the design and production of medical equipment and instrumentation are reported. Projects described include intercranial pressure transducers, leg negative pressure devices, a synthetic speech prosthesis for victims of cerebral palsy, and a Doppler blood flow instrument. Commercialization activities for disseminating and utilizing NASA technology, and new biomedical problem areas are discussed.

Source record↗
NASA NTRS1976

Elemental composition of airborne particulates and source identification - An extensive one year survey

Concentrations of 60 chemical elements in the airborne particulate matter were measured at 16 sites in Cleveland, OH over a 1 year period during 1971 and 1972 (45 to 50 sampling days). Analytical methods used included instrumental neutron activation, emission spectroscopy, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, the analytical methods, the use of several analytical facilities, and samples with concentrations below the detection limits are evaluated in detail. The data are discussed in relation to other studies and source origins. The trace constituent concentrations as a function of wind direction are used to suggest a practical method for air pollution source identification.

King, R. B.↗
NASA NTRS1976

Chemical evidence for the genesis of the ureilites, the achondrite Chassigny and the nakhlites

An investigation has been conducted of the ureilites and the achondrite Chassigny to elucidate differences in their petrogenesis. The experimental studies reported include the determination of elemental abundances by instrumental neutron activation analysis. Attention is given to lithophile elements in ureilites, lithophile elements in Chassigny, the relationship between Chassigny and the nakhlites, and siderophile trace elements in the ureilites.

Boynton, W. V.↗
NASA NTRS1976

Chemical characterization of lunar core 60009

A total of 27 major, minor and trace element abundances in 27 fine fractions (smaller than 1 mm) of core 60009 were determined by instrumental neutron activation analysis. The core was divided into five chemically defined stratigraphic units. Unit 1, 0.5 to 11.5 cm, is characterized by low Ca and Al abundances which increase towards the base of the unit and high ferromagnesian element abundances. Unit 2, 11.5 to 19.8 cm, has higher abundances of Ca and Al and lower abundances of ferromagnesian elements than unit 1 and is much more uniform. Unit 3, 19.8 to 25.7 cm is very similar to unit 1 and may have been derived from the same source region. Unit 4, 25.7 to 29.6 cm, has the highest Ca and Al abundances of all the units defined and the lowest abundances of ferromagnesian elements. The ferromagnesian elements generally decrease in abundance towards the base of the unit. This unit exhibits a positive Eu anomaly. Unit 5, 29.6 to 31.5 cm, has the lowest Ca and Al abundances and highest ferromagnesian abundances of all the units. The unit boundaries correspond well with major unit boundaries characterized by Duke and Nagle (1974) on the basis of textural parameters, structure, composition and thickness of layers.

Ali, M. Z.↗
NASA NTRS1976

Geochemistry of grain-size fractions of soils from the Taurus-Littrow valley floor

Results are presented for a study in which high-precision instrumental neutron activation analysis was applied to determine the abundances of seven rare-earth and nine other elements in two grain-size fractions (90 to 150 microns and less than 20 microns) of eight soils from the Taurus-Littrow Valley floor and one Apollo 11 bulk-soil fraction with grain sizes of less than 1 mm. Compositional differences between the two size fractions of two valley-floor soils are examined, and mixing of soil components is investigated. It is found that a five-component mixing model describes very adequately the chemical composition of bulk soils with grain sizes of less than 1 mm as mixtures of local Apollo 17 rock types (basalt, anorthositic gabbro, noritic breccia), orange glass, and meteorites, but does not describe well the chemical compositions of the other two size fractions. A ten-component model is used to show that the compositions of those two size fractions can be well represented as mixtures of the five components if the mineralogy and chemical composition of the basalt component are allowed to vary in the size fractions.

Korotev, R. L.↗
NASA NTRS1976

Chemical constraints for mare basalt genesis

Sequential instrumental neutron activation analysis was used to study 10 Apollo-15 rake basalts for 23 bulk, minor and trace elements and 13 basaltic fragments from the Apollo-15 deep drill core 15003 Station 8 for eight major, minor and trace elements. Attention is given here to La-MgO-TiO2 correlations, La/Sm-La and Sm/Eu-La correlations, the La/Sm-Sc correlation, and basalt genesis models.

Ma, M.-S.↗
NASA NTRS1977

Pontlyfni - A differentiated meteorite related to the group IAB irons

The abundances of 23 major and trace elements in the Pontlyfni meteorite have been measured by instrumental neutron activation analysis. The compositions of the metal and silicate fractions suggest a genetic relationship between Pontlyfni and the group IAB irons.

Davis, A. M.↗
NASA NTRS1977

Genesis of the Angra dos Reis and other achondritic meteorites

Major, minor, and trace element abundances were determined in seven Angra dos Reis samples, which included whole rocks, fassaite (clinopyroxene), olivine, and whitlockite separates, via sequential instrumental neutron activation analysis. The rare earth element abundance patterns and the trace element abundance patterns of this achondritic meteorite are discussed. A two-stage crystal-liquid fractionation model with source material containing olivine, orthopyroxene, and clinopyroxine is presented for the genesis of Angra dos Reis. Multilinear regression analysis was used to estimate possible composition and properties of the parent magmas. Angra dos Reis was compared with other achondrites, cumulate eucrites and nakhlites in particular. It is thought that the unique Angra dos Reis could not be related to those achondrites by crystal-liquid fractionation of the same parent body.

Ma, M.-S.↗
NASA NTRS1977

Test of a model for trace element partition during closed-system solidification of a silicate liquid

Trace-element concentrations in separated minerals and rock fragments from a coarsely crushed and sieved sample of medium-grained lunar basalt are determined by high-precision instrumental neutron activation analysis for three main purposes. These are: (1) to test a previously proposed model for describing trace-element behavior during solidification of a silicate liquid under conditions of a closed system; (2) to compare trace-element concentrations among different size fractions of a comminuted basalt; and (3) to investigate small-scale heterogeneity within a single medium-grained basalt. It is found that an excellent mass balance for the whole rock is attained in terms of the trace-element concentrations of the component minerals and mesostasis, that the mixing model describing this mass balance yields a superior modal analysis for the whole rock, and that different size fractions of the coarsely crushed basalt vary in mineral composition. The closed-system model is shown to account properly for the average behavior of the trace elements during solidification of the basalt, and values of distribution coefficients are obtained for incompatible elements in that rock.

Haskin, L. A.↗
NASA NTRS1978

A 'chondritic' eucrite parent body - Inference from trace elements

Thirty-three elements were analyzed by radiochemical and instrumented neutron activation in four eucrites - Juvinas (brecciated), Ibitira (vesicular, unbrecciated) and Moore County and Serra de Mage (both cumulate, unbrecciated). Nebular and planetary effects are distinguished in the C1-normalized abundance patterns arranged in the order of volatility. Lithophile, chalcophile, and siderophile patterns are discussed; the stepped lithophile pattern reveals the dominance of nebular processes while the siderophile pattern retains little sign of nebular processes and instead reflects planetary metal-silicate partition. Volatiles were apparently accreted as a fractionated C3-like component, and consistent but subtle C1-normalized abundance differences between eucrites result from crystal/liquid differentiation.

Morgan, J. W.↗