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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1997

Structure of potato tubers formed during spaceflight

Potato (Solanum tuberosum L. cv. Norland) explants, consisting of a leaf, axillary bud, and small stem segment, were used as a model system to study the influence of spaceflight on the formation of sessile tubers from axillary buds. The explants were flown on the space shuttle Columbia (STS-73, 20 October to 5 November 1995) in the ASTROCULTURE (TM) flight package, which provided a controlled environment for plant growth. Light and scanning electron microscopy were used to compare the precisely ordered tissues of tubers formed on Earth with those formed during spaceflight. The structure of tubers produced during spaceflight was similar to that of tubers produced in a control experiment. The size and shape of tubers, the geometry of tuber tissues, and the distribution of starch grains and proteinaceous crystals were comparable in tubers formed in both environments. The shape, surface texture, and size range of starch grains from both environments were similar, but a greater percentage of smaller starch grains formed in spaceflight than on Earth. Since explant leaves must be of given developmental age before tubers form, instructions regarding the regular shape and ordered tissue geometry of tubers may have been provided in the presence of gravity. Regardless of when the signalling occurred, gravity was not required to produce a tuber of typical structure.

manned↗
NASA NTRS1973

A mechanical property and stress corrosion evaluation of 431 stainless steel alloy

The mechanical properties of type 431 stainless steel in two conditions: annealed bar and hardened and tempered bar are presented. Test specimens, manufactured from approximately 1.0 inch (2.54 cm) diameter bar stock, were tested at temperatures of 80 F (+26.7 C), 0 F (-17.8 C), -100 F (-73 C), and -200 F (-129 C). The test data indicated excellent tensile strength, notched/unnotched tensile ratio, ductility, shear, and impact properties at all testing temperatures. Results of the alternate immersion stress corrosion tests on stressed and unstressed longitudinal tensile specimens 0.1250 inch (0.3175 cm) diameter and transverse C-ring specimens, machined from 1.0 inch (2.54 cm) diameter bar stock, indicated that the material is not susceptible to stress corrosion cracking when tested in a 3.5 percent NaCl solution for 180 days.

Montano, J. W.↗
NASA NTRS1973

Measurements of the Michigan Airglow Observatory from 1971 to 1973 at Ester Dome Alaska

The Michigan Airglow Observatory (MAO) was located at Ester Dome Observatory, College, Alaska (latitude: 64 deg 53'N, longitude: 148 deg 03'W) since October, 1971. The MAO houses a 6-inch Fabry-Perot interferometer, a 2-channel monitoring photometer and a 4-channel tilting filter photometer. The Fabry-Perot interferometer was used extensively during the winter observing seasons of 1971-72 and 1972-73 to measure temperature and mass motions of the neutral atmosphere above approximately 90 kilometers altitude. Neutral wind data from the 1971-72 observing season as measured by observing the Doppler shift of the gamma 6300 A atomic oxygen emission line are presented.

Mcwatters, K. D.↗
NASA NTRS1973

UHURU results on galactic X-ray sources.

Consideration of the nature of the galactic X-ray sources located with the aid of the UHURU satellite. A brief description is given of the X-ray emission of the Galaxy as a whole. The general properties of sources similar to Sco X-1 (called Sco X-1-like sources) are discussed, as well as the properties of three pulsating sources showing evidence of a binary nature. Finally, some new results concerning two objects - GX263+3 (2U0900-40) and the X-ray source in the Small Magellanic Cloud (2U0115-73) - which both show evidence of a binary nature, yet have some of the properties of the Sco X-1-like objects are presented. The links noted between the Sco X-1-like objects and the pulsating binary sources lead to the suggestion that all of the galactic X-ray sources (except supernova remnants) may in fact be binaries.

Tananbaum, H. D.↗
NASA NTRS1973

Low temperature mechanical properties, fractographic and metallographic evaluation of several alloy steels

The mechanical properties are presented of alloy steels, 4130, 4140, 4340, 6150, and 8740. Test specimens were manufactured from approximately 1.00 inch (2.54 cm) diameter bar stock which had been heat treated to two different hardness levels. The following mechanical tests were performed at temperatures of 80 F (+26.7 C), 0 F (-17.8 C), -100 F (-73 C), and -200 F (-129 C): (1) tensile test (Ultimate, yield, modulus, elongation, and reduction of area), (2) notched tensile test, (3) charpy V-notched impact test (impact energy), and (4) double shear strength test (ultimate and yield). The test data indicate excellent tensile strength, notched/unnotched tensile ratios, ductility, impact, and shear properties at all test temperatures, except at -200 F (-129 C) where the impact strength of the higher strength group of alloy steels, 4130 (Rc-37) and 4140 (Rc-44) decreased to approximately 9 ft. lbs. (12 joules) and 6 ft. lbs. (8 joules), respectively. Chemical, metallographic, and fractographic analyses were also performed to evaluate microstructure, microhardness and the effect of decrease in temperature on the ductile to brittle failure transition.

Montano, J. W.↗
NASA NTRS1973

Viking orbiter 1975 articulation control actuators

The articulation subsystem actuators were rigorously tested in severe environments. They were operated through temperature ranges from -73 C to +121 C. In each case the temperature rate of change was at maximum. The actuator under test at room temperature was put into a pre-chilled or preheated chamber. Satisfactory performance was obtained throughout this full temperature range and under the temperature shock conditions above. However, at temperatures below -78 C some leakage was experienced through the O-ring seal around the shaft. The actuators were subjected to severe vibration and 500 g shock test with a time duration of 0.0007 seconds. The scan actuator was life tested by operating it from stop to stop through 2,000 cycles with 20,000 start-stop procedures randomly distributed through the 2,000 cycles.

Perkins, G. S.↗
NASA NTRS1973

Applications of ERTS-1 Data Collection System (DCS) in the Arizona Regional Ecological Test Site (ARETS)

The author has identified the following significant results. The DCS water-stage data from the USGS streamflow gaging station on the Verde River near Camp Verde furnished information sufficient for the accurate computation of daily mean streamflow rates during the first 2 months of operation. Daily mean flow rates computed from the DCS data agreed with those computed from the digital recorder data within + or - 5% during periods of stable or slowly changing flow and within + or - 10% during periods of rapidly changing high flow. The SRP was furnished near-real time DCS information on snow moisture content and streamflow rates for use in the management and operation of the multiple-use reservoir system. The SRP, by prudent water management and the use of near-real time hydrologic data furnished by microwave and ERTS DCS telemetry, was successful in anticipating the amount of flow into the Salt and Verde Rivers and in the subsequent release of water at rates that did not create flooding in metropolitan Phoenix. Only minor flooding occurred along the Gila River west of Phoenix. According to the Maricopa County Civil Defense agency, wage and salary losses of about $11,400,000 resulted from closing of roads across the Salt River in the winter and spring of 1972-73; however, the number and duration of the closing were minimized by use of DCS data.

Schumann, H. H.↗
NASA NTRS1973

On multidisciplinary research on the application of remote sensing to water resources problems

Research objectives during 1972-73 were to: (1) Ascertain the extent to which special aerial photography can be operationally used in monitoring water pollution parameters. (2) Ascertain the effectiveness of remote sensing in the investigation of nearshore mixing and coastal entrapment in large water bodies. (3) Develop an explicit relationship of the extent of the mixing zone in terms of the outfall, effluent and water body characteristics. (4) Develop and demonstrate the use of the remote sensing method as an effective legal implement through which administrative agencies and courts can not only investigate possible pollution sources but also legally prove the source of water pollution. (5) Evaluate the field potential of remote sensing techniques in monitoring algal blooms and aquatic macrophytes, and the use of these as indicators of lake eutrophication level. (6) Develop a remote sensing technique for the determination of the location and extent of hydrologically active source areas in a watershed.

Clapp, J. L.↗
NASA NTRS1974

Kansas environmental and resource study: A Great Plains model. Extraction of agricultural statistics from ERTS-1 data of Kansas

The author has identified the following significant results. Wheat area, yield, and production statistics as derived from satellite image analysis, combined with a weather model, are presented for a ten county area in southwest Kansas. The data (representing the 1972-73 crop year) are compared for accuracy against both the USDA August estimate and its final (official) tabulation. The area estimates from imagery for both dryland and irrigated winter wheat were within 5% of the official figures for the same area, and predated them by almost one year. Yield on dryland wheat was estimated by the Thompson weather model to within 0.1% of the observed yield. A combined irrigated and dryland wheat production estimate for the ten county area was completed in July, 1973 and was within 1% of the production reported by USDA in February, 1974.

Morain, S. A.↗
NASA NTRS1973

Spaceflight performance of silver coated FEP Teflon as a thermal control surface on the IMP-1 spacecraft

A second surface mirror type coating, vapor deposited silver on FEP Teflon, was used as a thermal control surface for one of the experiments aboard the Imp-I spacecraft. This coating was selected to obtain the low operating temperature required for this experiment. Initial flight temperature of this thermal control surface was -70.5 C, very close to the predicted value of -73 C and at a very satisfactory level. Since temperatures within the spacecraft interior are not at this desired low level, the detectors had to be mounted exterior to the spacecraft with a good view of space, preferably in an area shaded from sunlight. When this latter preference proved unobtainable, the detectors were mounted on an aluminum plate located on the exterior of the spacecraft, parallel to the spin axis but rotating about the solar vector. The mounting plate was approximately 6.5 inches by 7.5 inches by 0.125 inches thick. To achieve the desired temperature level with the mounting plate in such a location, the thermal design had to minimize not only the effects of the relatively warm spacecraft environment but also the effects of the incident solar energy.

Hoffman, R. H.↗
NASA NTRS1974

The cartographic application of ERTS/RBV imagery in polar regions

The author has identified the following significant results. Preliminary analysis of the late 1973-74 Antarctic imagery, when compared to 1972-73 imagery and existing map sources, clearly shows changes in the ice fronts, glacier movement, and the existence of possible new geographical features.

Macdonald, W. R.↗
NASA NTRS1974

Task 60 test report, evaluation of IRIG-A 21 channel constant bandwith FM multiplexer for shuttle development flight instrumentation

A frequency modulated (FM) multiplexer, consisting of 21 IRIG-A constant bandwidth (CBW) voltage-controlled oscillators (VCO's) was tested to determine its suitability for use in multiplexing 21 data signals which have frequency ranges of dc to 2 kHz. Tests were preformed with the composite signal, consisting of the mixed outputs of the 21 VCO's connected directly to a set of subcarrier discriminators, with the signal recorded on magnetic tape and played back through the discriminators and with the signal transmitted by a frequency-modulated FM S-band radio frequency RF transmitter to a FM receiver and through the subcarrier discriminators. Tape speed flutter was induced to determine the reduction in flutter noise which can be obtained by the tape speed compensation equipment. The RF transmission test included transmitting the composite signal at a nominal RF received signal of -73 dbm and at RF levels of -83 and -86 dbm.

Haddick, C. M.↗
NASA NTRS1974

Nonlinear models for estimating GSFC travel requirements

A methodology is presented for estimating travel requirements for a particular period of time. Travel models were generated using nonlinear regression analysis techniques on a data base of FY-72 and FY-73 information from 79 GSFC projects. Although the subject matter relates to GSFX activities, the type of analysis used and the manner of selecting the relevant variables would be of interest to other NASA centers, government agencies, private corporations and, in general, any organization with a significant travel budget. Models were developed for each of six types of activity: flight projects (in-house and out-of-house), experiments on non-GSFC projects, international projects, ART/SRT, data analysis, advanced studies, tracking and data, and indirects.

Buffalano, C.↗
NASA NTRS1973

Turbine Design and Application, Volume 2

NASA has an interest in turbines related primarily to aeronautics and space applications. Airbreathing turbine engines provide jet and turboshaft propulsion, as well as auxiliary power for aircraft. Propellant -driven turbines provide rocket propulsion and auxiliary power for spacecraft. Closed-cycle turbine engines using inert gases, organic fluids, and metal fluids have been studied for providing long-duration electric power for spacecraft. Other applications of current interest for turbine engines include land-vehicle (cars, trucks, buses, trains, etc.) propulsion power and ground-based electrical power. In view of the turbine-system interest and efforts at Lewis Research Center, a course entitled "Turbine Design and Application" was presented during 1968-69 as part of the In-House Graduate Study Program. The course was somewhat revised and again presented in 1972-73. Various aspects of turbine technology were covered including thermodynamic and fluid-dynamic concepts, fundamental turbine concepts, velocity diagrams, losses, blade aerodynamic design, blade cooling, mechanical design, operation, and performance. The notes written and used for the course have been revised and edited for publication. Such a publication can serve as a foundation for an introductory turbine course, a means for self-study, or a reference for selected topics. The first volume presented the material covering thermodynamic and fluid-dynamic concepts, fundamental turbine concepts, and velocity diagram design. This second volume presents the material related to blade aerodynamic design and turbine energy losses.

Arthur J Glassman↗
NASA NTRS1974

Transference of ERTS-1 spectral signatures in time and space

Some earth resources maps obtained from ERTS-1 multispectral scanning data in 1972-73 were found to contain modulo six banding. A method was found to recalibrate nonconformable data from the sensors in order to eliminate banding in the map output. This investigation led to developing a recalibration method for transferring data signatures from one scene to another scene separated from the first either temporally or spatially. The method was generally successful, although difficulties were encountered in transferring signatures from one season to another for the same location.

Merembeck, B. F.↗
NASA NTRS1974

Ice growth in Duluth harbor and western Lake Superior

Ice growth computation for the Duluth-Superior harbor and the adjacent Lake Superior waters, using the heat budget balance, agrees well with the measured ice values for the 1972-73 winter season. ERTS data is used for the determination of ice albedo and the resulting ice decay rate on Lake Superior. During the period of ice packing near Duluth, the calculated ice decay rates, combined with the ERTS data on the extent and the condition of the ice field indicate maximum ice packing between March 20-27, when the packed ice field, exhibiting albedo values above 70% reached an average 60 cm thickness. The results offer a method for description of ice packing which could be used for ice forecasting on Lake Superior if more frequent ERTS images were available.

Sydor, M.↗
NASA NTRS1981

The diffuse extreme-ultraviolet background - Constraints on hot coronal plasma

The Apollo-Soyuz data and data reported by Cash et al. (1976) have been reanalyzed in terms of both isothermal models and temperature distribution models. In the latter case, a power-law form is assumed for the relation between emission measure and temperature. A new upper limit on diffuse flux in the 20-73 eV band derived from Apollo-Soyuz observations made in the earth's shadow has been incorporated in the calculation. In the considered investigation the results of the new analysis are presented and the implications for the physical properties of the hot component of the interstellar medium are discussed. The analysis of the Berkeley extreme ultraviolet (EUV) diffuse background measurements using either isothermal or power law temperature distribution models for the emitting plasma indicates excellent qualitative agreement with hard X-ray data that suggest the sun to be immersed in a hot plasma that pervades most of space out to approximately 100 pc.

Paresce, F.↗
NASA NTRS1981

On the nature of the apparent response of the vorticity area index to the solar magnetic field

The apparent response of the vorticity area index to the solar magnetic field is confined to tropospheric regions of intense circulation. Discussions and calculations that include larger volumes of the troposphere would not be expected to show a significant sun-weather effect. Analysis of the effect in time intervals outside the original 1963-73 is also discussed. An assessment of this sun-weather effect at the present time is given.

Wilcox, J. M.↗