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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

A brief review of digital image processing

The review is presented with particular reference to Skylab S-192 and Landsat MSS imagery. Attention is given to rectification (calibration) processing with emphasis on geometric correction of image distortions. Image enhancement techniques (e.g., the use of high pass digital filters to eliminate gross shading to allow emphasis of the fine detail) are described along with data analysis and system considerations (software philosophy).

Billingsley, F. C.↗
NASA NTRS1976

The interaction of small particles and thin films of metals with gases. I - A brief review of the early stages of oxide formation

Existing work on gas-solid reactions making use of thin film technologies is reviewed. The discussion concentrates on two major areas of gas-metal interactions: chemisorption and the early stages of oxidation of metals (characterized by a non-volatile reaction product) and catalytic surface reactions (featuring volatile reaction products). A brief survey of oxide formation on metals is presented. Here it is of importance to distinguish between reactions on continuous thin film substrates and reactions on particulate deposits. Small particle-gas interactions also affect the nucleation, growth and sintering processes of thin films. It is shown that various combinations of UHV and high resolution electron microscopy techniques, which include in situ experimentation, can provide the appropriate tools for studying angstrom particle chemistry.

Poppa, H.↗
NASA NTRS1976

Skylab results - Review and outlook

In the history of space flight, Project Skylab marks the transition from short manned flights to long-time manned orbital operations, from single-purpose spacecraft to multipurpose space stations, and from a time of space exploration to a time of space utilization. In the present paper, some of the Skylab scientific programs in the areas of solar physics, stellar astronomy, space physics, earth observations, life sciences, and materials sciences are reviewed. Visible, UV, and X-ray observations showed the sun's surface to be far more active and more differentiated than was earlier assumed. The unexpected apparition of the comet Kohoutek provided valuable information on the composition of cometary nuclei and tails. Pictures taken with earth-looking cameras have provided insight into specific data analysis and assessment problems. Results of the materials science program offer much promise for future work.

Stuhlinger, E.↗
NASA NTRS1976

Annual review of materials science in space

The weightlessness of objects in free fall permits numerous novel manipulations of multiphase systems and suppresses buoyancy and convection in liquids and gases. In the present paper, the prospects for materials science in space are examined on the basis of the materials experiments performed on Skylab, including biological preparations and crystal growth. Plans for technology-oriented research on Spacelab are reviewed.

Bredt, J. H.↗
NASA NTRS1976

A review of the Jovian magnetosphere based upon Pioneer 10 and 11

A review and analysis are presented of data derived from the Pioneer 10 and Pioneer 11 flybys of Jupiter on the Jovian plasma, magnetic field, and energetic particles in circumjovian space. The design of the space probes is described along with the principal experiments flown. Overall features of the Jovian magnetosphere are drawn and contrasted with the earth's magnetosphere. The trajectories of the two space probes are contrasted and their data on Jupiter's plasmasphere are correlated. Isointensity contours and count rates of energetic particles are plotted, flux tubes within the Jovian magnetosphere are mapped, the ring current (plasma torus) encircling the planet is described, and possible effects of solar wind and of the moons immersed in Jupiter's magnetosphere are considered.

Trainor, J. H.↗
NASA NTRS1977

Supercooling on the lunar surface - A review of analogue information

Terrestrial analog studies of the phase petrology of supercooled melts and rapid crystal growth are reviewed for possible light shed on lunar crystallization, supercooling, and petrogenic processes, in particular rapid consolidation of lavas extruded on the lunar surface, and impact liquids. Crystallization of major constituent minerals (olivine, pyroxene, plagioclase) in dendritic or skeletal forms is found much more characteristic of lunar igneous rocks than of terrestrial counterparts. Olivine and pyroxene occur often as skeletal phenocrysts, and their stage of crystallization is crucial to the genesis and cooling history of porphyritic lavas. Widespread occurrence of glass and of immature radiate crystallization, particularly of highly zoned pyroxenes and zoned plagioclase, is noted.

Donaldson, C. H.↗
NASA NTRS1977

A review of the thermonuclear runaway model of a nova outburst

Kraft's (1963) model for a nova outburst caused by a thermonuclear runaway in the hydrogen-rich matter accreted onto the white dwarf in a binary system is reviewed. Hydrostatic and hydrodynamic studies of this phenomenon are summarized, analyses of shock ejection based on hydrodynamic computer codes are discussed, and one specific hydrodynamic code is outlined. Results obtained with this code are presented and evaluated for an initial model containing a white dwarf with a hydrogen-rich envelope of 0.0001 to 0.001 solar mass in hydrostatic and thermal equilibrium. It is shown that an implicit hydrodynamic computer code is required in order to study the thermonuclear-runaway phenomenon. The early evolution of three models with different intrinsic luminosities is illustrated, and enhancement of CNO nuclei at the bottom of the hydrogen-rich envelope is investigated. It is suggested that the concentration of C-13, N-15, and O-17 should be greatly enhanced in nova ejecta.

Sparks, W. M.↗
NASA NTRS1976

Critical review of models for the evolution of high-Ti mare basalts

Current models for the evolution of REE abundances in high-Ti mare basalts are reviewed, the models falling into two classes: simple cumulate remelting models and complex assimilation and hybridization models. Calculations show that the total melting of a cumulate having the modal mineralogy of high-Ti mare basalts can provide for the approximate level of enrichment of REE relative to chondrites, but results in a poor match for the Apollo 17 high-Ti basalt REE pattern.

Drake, M. J.↗
NASA NTRS1977

A review of advanced rotor research

This paper reviews advanced-rotor concepts including the advancing blade concept, the circulation control rotor, the X-wing rotor, the variable diameter rotor, the hingeless tilt rotor, the bearingless main rotor, the composite structures rotor, the variable geometry rotor, the multicyclic controllable pitch rotor, the multicyclic controllable twist rotor, and the live twist rotor. The rotor concepts are discussed in terms of performance (cruise speed, and lift/drag ratio) and dynamic loads and vibration.

Kelly, M. W.↗
NASA NTRS1976

Solar cycle review /General aspects/

Several topics are discussed in this review of the solar cycle. The basic solar-interplanetary magnetic structure is considered, and the high speed solar wind streams and their sunspot cycle variation are described, with attention to the sunspot cycle variation, the high speed solar wind streams and geomagnetic disturbances, and the causes of changes of the north-south component of the interplanetary magnetic field. Solar storms, solar flares, and magnetic bubbles are examined with attention directed to the solar cycle variation of transient polar activities and the interplanetary disturbances associated with solar storms. Some features of cosmic rays, the 11-year cycle variation and the Forbush decreases, are considered. Attention is also directed to the terrestrial atmosphere and to the outer planets and their relation to the solar cycle.

Akasofu, S.-I.↗
NASA NTRS1977

A review of available LC/50/ data

Several gaseous products of pyrolysis and combustion have been evaluated for LC/50/, defined as the concentration of toxic gas in the atmosphere being inhaled by test animals that will produce death in 50% of the animals within a given time period. The products tested included CO, HCl, HF, HCN, NO2, and SO2. It was found that HCN and NO2 were consistently the most toxic of the gases reviewed, and that mice were more susceptible than rats to HCl and HF, although less susceptible than rats to NO2. Extrapolation of LC/50/ data to humans indicates that metabolic rate may be a valid basis for extrapolation when the toxicity mechanism is interference with oxygen transport and utilization, or pulmonary edema, but not when it is irritation and damage to the upper respiratory tract.

Hilado, C. J.↗
NASA NTRS1973

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 1B: Concise review

Reports on the design process, support of the design process, IPAD System design catalog of IPAD technical program elements, IPAD System development and operation, and IPAD benefits and impact are concisely reviewed. The approach used to define the design is described. Major activities performed during the product development cycle are identified. The computer system requirements necessary to support the design process are given as computational requirements of the host system, technical program elements and system features. The IPAD computer system design is presented as concepts, a functional description and an organizational diagram of its major components. The cost and schedules and a three phase plan for IPAD implementation are presented. The benefits and impact of IPAD technology are discussed.

Miller, R. E., Jr.↗
NASA NTRS1978

A review of NASA's propulsion programs for aviation

A review of five NASA engine-oriented propulsion programs of major importance to civil aviation are presented and discussed. Included are programs directed at exploring propulsion system concepts for (1) energy conservation subsonic aircraft (improved current turbofans, advanced turbofans, and advanced turboprops); (2) supersonic cruise aircraft (variable cycle engines); (3) general aviation aircraft (improved reciprocating engines and small gas turbines); (4) powered lift aircraft (advanced turbofans); and (5) advanced rotorcraft.

Stewart, W. L.↗
NASA NTRS1978

A review of electron bombardment thruster systems/spacecraft field and particle interfaces

Information on the field and particle interfaces of electron bombardment ion thruster systems was summarized. Major areas discussed were the nonpropellant particles, neutral propellant, ion beam, low energy plasma, and fields. Spacecraft functions and subsystems reviewed were solar arrays, thermal control systems, optical sensors, communications, science, structures and materials, and potential control.

Byers, D. C.↗
NASA NTRS1977

Quarterly literature review of the remote sensing of natural resources

The Technology Application Center reviewed abstracted literature sources, and selected document data and data gathering techniques which were performed or obtained remotely from space, aircraft or groundbased stations. All of the documentation was related to remote sensing sensors or the remote sensing of the natural resources. Sensors were primarily those operating within the 10 to the minus 8 power to 1 meter wavelength band. Included are NASA Tech Briefs, ARAC Industrial Applications Reports, U.S. Navy Technical Reports, U.S. Patent reports, and other technical articles and reports.

Fears, C. B.↗
NASA NTRS1978

Grain formation in astronomical systems: A critical review of condensation processes

An analysis is presented of the assumption and the applicability of the three theoretical methods for calculating condensations in cosmic clouds where no pre-existing nuclei exist. The three procedures are: thermodynamic equilibrium calculations, nucleation theory, and a kinetic treatment which would take into account the characteristics of each individual collision. Thermodynamics provide detailed results on the composition temperature and composition of the condensate provided the system attains equilibrium. Because of the cosmic abundance mixture of elements, large supersaturations in some cases and low pressures, equilibrium is not expected in astronomical clouds. Nucleation theory, a combination of thermodynamics and kinetics, has the limitations of each scheme. Kinetics, not requiring equilibrium, avoids nearly all the thermodynamics difficulties but requires detailed knowledge of many reactions which thermodynamics avoids. It appears to be the only valid way to treat grain formation in space. A review of experimental studies is given.

Donn, B.↗
NASA NTRS1978

A review of the theory of trailing edge noise

Literature on the theory of the generation of sound by the interaction of low Mach number turbulent flow with the edge of a semi-infinite rigid plate is critically reviewed. Three different approaches to the subject are identified, consisting of theories based on (1) Lighthill's acoustic analogy; (2) the solution of special, linearized hydroacoustic problems; and (3) ad hoc aerodynamic source models. When appropriately interpreted, all relevant theories produce essentially identical predictions in the limit of very small Mach numbers. None of the theories discusses the implications of the Kutta condition, however, nor of the effect of forward flight and source motion relative to the trailing edge. An outline of a redevelopment of the theory is included to give a unified view of the problem, exhibit the significance of the various approximations, and incorporate the effect of mean motion and of the Kutta condition.

Howe, M. S.↗