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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 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Surfaces and interfaces of glass and ceramics; Proceedings of the International Symposium on Special Topics in Ceramics, Alfred University, Alfred, N.Y., August 27-29, 1973

The characterization of surfaces and interfaces is considered along with the infrared spectra of several N-containing compounds absorbed on montmorillonites, applications of surface characterization techniques to glasses, the observation of electronic spectra in glass and ceramic surfaces, a method for determining the preferred orientation of crystallites normal to a surface, and the friction and wear behavior of glasses and ceramics. Attention is given to the wear behavior of cast surface composites, an experimental investigation of the dynamic and thermal characteristics of the ceramic stock removal process, a dynamic elastic model of ceramic stock removal, and the structure and properties of solid surfaces. Individual items are announced in this issue.

Frechette, V. D.↗
NASA NTRS1975

Preliminary design report, Large Space Telescope OTA/SI Phase B study: High speed area photometer

A photometer is examined which combines several features from separate instruments into a single package. The design presented has both point and area photometry capability with provision for inserting filters to provide spectral discrimination. The electronics provide for photon counting mode for the point detectors and both photon counting and analog modes for the area detector. The area detector also serves as a target locating device for the point detectors. Topics discussed include: (1) electronic equipment requirements, (2) optical properties, (3) structural housing for the instrument, (4) motors and other mechanical components, (5) ground support equipment, and (6) environment control for the instrument. Engineering drawings and block diagrams are shown.

Source record↗
NASA NTRS1975

Materials considerations

Materials problems are examined that may be encountered within a hydrogen energy system. Emphasis is placed on hydrogen embrittlement, corrosion, oxidation, and erosion. Other factors discussed include: degradation of mechanical properties of structural alloys, system reliability, and maintenance costs.

Gray, H. R.↗
NASA NTRS1980

Faired instrumentation for aerodynamic tests

Streamlined package is installed and removed without altering aerodynamic properties of structure being tested. Method uses lightweight materials so that blade balance is maintained.

Long, W. C.↗
NASA NTRS1978

Characterization of large 2219 aluminum alloy hand forgings for the space shuttle solid rocket booster

The mechanical properties, including fracture toughness, and stress corrosion properties of four types of 2219-T852 aluminum alloy hand forgings are presented. Weight of the forgings varied between 450 and 3500 lb at the time of heat treatment and dimensions exceeded the maximum covered in existing specifications. The forgings were destructively tested to develop reliable mechanical property data to replace estimates employed in the design of the Space Shuttle Solid Rocket Booster (SRB) and to establish minimum guaranteed properties for structural refinement and for entry into specification revisions. The report summarizes data required from the forgers and from the SRB Structures contractor.

Brennecke, M. W.↗
NASA NTRS1980

Eutectic alloys. Citations from the International Aerospace Abstracts data base

These 250 abstracts from the international literature provide summaries of the preparation, treatments, composition and structure, and properties of eutectic alloys. Techniques for directional solidification and treatments including glazing, coating, and fiber reinforcement are discussed. In addition to the mechanical and thermal properties, the superconducting, corrosion, resistance, and thermionic emission and adsorption properties are described.

Moore, P.↗
NASA NTRS1979

Ultrathin films as photomechanical transducers

In order to investigate the photomechanical effect in ultrathin films, several commercially available polymers of various structure and properties have been studied experimentally below the glass transition temperature. In the experiments using an Instron test machine equipped with a 200-g load cell and a microscope stage illuminator as the light source, the load at the fixed strain was recorded as a function of time. Plots of the steady-state change in stress as a function of the intensity of the incident radiation are presented for several of the materials studied. The response is found to be linear; the greater the intensity of the incident radiation, the greater is the change in stress.

Sarbolouki, M. N.↗
NASA NTRS1982

"SiAION" Materials for Advanced Structural Applications

New ceramics for gas turbines and other applications are strong, oxidation resistant, and chemically stable. Recently prepared state-of-the-art report on SiAION materials includes work on phase relations, crystal structure, synthesis, fabrication, micro-structure, and properties of various SiAION's.

Dutta, S.↗
NASA NTRS1981

Subsatellite Orbital Analysis Program (SOAP) user's guide

The features and use of the subsatellite operational analysis are examined. The model simulates several Earth-orbiting vehicles, their pilots, control systems, and interaction with the environment. The use of the program, input and output capabilities, executive structures, and properties of the vehicles and environmental effects which it models are described.

Castle, K. G.↗
NASA NTRS1982

Poly(aryl ethers) and related polysiloxane copolymer molecular coatings: Preparation and radiation degradation

The radiation degradation of poly(arylene ether sulfones) and related materials is studied. These basic studies are important both as a means to developing stronger, more stable matrix resins for composite materials, as well as to improve the data base in regard to chemical structure-physical property relationships. Thirty homo and copolymers were synthesized, at least partially characterized and, in several cases suitable film casting techniques were developed. Four samples were chosen for initial radiation degradation. Poly(dimethyl siloxane) soft bocks/segments can preferentially migrate to the surface of copolymer films. Since siloxanes are utilized as thermal control coatings, this form of 'molecular' coating is of interest. The chemistry for preparing such copolymers with any of the polymers described was demonstrated.

Mcgrath, J. E.↗
NASA NTRS1982

A satellite magnetic model of northeastern South American aulacogens

Magnetic modeling of the Amazon River and Takatu Aulacogens in northeastern South America illustrate the utility of satellite magnetic data in characterizing the properties and structure of the lithosphere. Specifically, reduction of preliminary Magsat scalar magnetic anomaly data to an equivalent condition of vertical polarization shows a general correlation between magnetic anomaly minima and the Amazon River and Takatu Aulacogens. Surface gravity data demonstrate a correlative positive anomaly. Spherical earth modeling of the magnetic data indicates a less magnetic crust associated with the aulacogens which is compatible with previous studies over the Mississippi River Aulacogen and Rio Grande Rift in North America.

Longacre, M. B.↗
NASA NTRS1982

Radiation from the accretion column of magnetized neutron stars

Some developments in radiative transfer for magnetized neutron star conditions, and their application in models of the structure and properties of self-consistent polar cap emission regions are reviewed. Several of the assumptions and uncertainties involved are discussed, and present problems are indicated.

Meszaros, P.↗
NASA NTRS1982

Containerless processing of Nb-Ge alloys in a long drop tube

The thirty-two meter drop tube at the Marshall Space Flight Center was used to study the effect of zero gravity containerless processing on the structure and properties of materials. The concept involves the suppression of heterogeneous nucleation of solid in liquid and, therefore, solidification accompanied by large degrees of undercooling. Under these conditions metastable phases can be formed or, at the very least, unique nonequilibrium microstructures (containing equilibrium phases) with unique properties can be produced. The drop tube solidification was applied to niobium base alloys with emphasis on the Nb-Ge binary system in an effort to produce metastable phases with high superconducting transition temperatures in bulk specimens. In the past, only lower Ge alloys (Nb-13 a/o, Nb-18 a/o, and Nb-22 a/o) could be undercooled. Higher Ge alloys (e.g., Nb-25 a/o Ge and Nb-27 a/o Ge) can now be undercooled on a routine basis.

Bayuzick, R. J.↗
NASA NTRS1981

The thermal balance of the lower atmosphere of Venus

The temperature near the surface of Venus (now established at 730 K) is remarkably high in view of Venus's cloud cover which causes the planet to absorb even less sunlight than does Earth. Early attempts to understand the thermal balance that leads to this unusual state were hindered by the lack of basic information regarding the composition, temperature-pressure structure, cloud properties, and wind field of the lower atmosphere. A series of successful space missions have measured many of the above quantities that control the transfer of heat in Venus's lower atmosphere. The relevant observational data are summarized and the attempts to understand the thermal balance of Venus's atmosphere below the cloud tops are reviewed. The data indicate that sufficient sunlight penetrates to deep atmospheric levels and is trapped by the large thermal opacity of the atmosphere to essentially account for the high temperatures observed.

Tomasko, M. G.↗
NASA NTRS1983

Flutter analysis of advanced turbopropellers

The two-dimensional subsonic cascade unsteady aerodynamic theory of Jones and Rao (1975) has been modified to account for the variable sweep angles of the blades of advanced turbopropellers. The aerodynamics and the structural modal properties have been formally integrated to determine the generalized aerodynamic coefficients matrix for the blade modes. Modal flutter analysis has been conducted for two SR-5 five- and ten-blade propellers, and analytical results have been found to be in very good agreement with wind tunnel test data.

Elchuri, V.↗
NASA NTRS1983

The thermal balance of the lower atmosphere of Venus

The temperature near the surface of Venus (now established at 730 K) is remarkably high in view of Venus's cloud cover which causes the planet to absorb even less sunlight than does earth. Early attempts to understand the thermal balance that leads to this unusual state were hindered by the lack of basic information regarding the composition, temperature-pressure structure, cloud properties, and wind field of the lower atmosphere. A series of successful space missions have measured many of the above quantities that control the transfer of heat in Venus's lower atmosphere. The relevant observational data are summarized and the attempts to understand the thermal balance of Venus's atmosphere below the cloud tops are reviewed. The data indicate that sufficient sunlight penetrates to deep atmospheric levels and is trapped by the large thermal opacity of the atmosphere to essentially account for the high temperatures observed. Previously announced in STAR as N83-19672

Tomasko, M. G.↗
NASA NTRS1983

Effects of cobalt in nickel-base superalloys

The role of cobalt in a representative wrought nickel-base superalloy was determined. The results show cobalt affecting the solubility of elements in the gamma matrix, resulting in enhanced gamma' volume fraction, in the stabilization of MC-type carbides, and in the stabilization of sigma phase. In the particular alloy studied, these microstructural and microchemistry changes are insufficient in extent to impact on tensile strength, yield strength, and in the ductilities. Depending on the heat treatment, creep and stress rupture resistance can be cobalt sensitive. In the coarse grain, fully solutioned and aged condition, all of the alloy's 17% cobalt can be replaced by nickel without deleteriously affecting this resistance. In the fine grain, partially solutioned and aged condition, this resistance is deleteriously affected only when one-half or more of the initial cobalt content is removed. The structure and property results are discussed with respect to existing theories and with respect to other recent and earlier findings on the impact of cobalt, if any, on the performance of nickel-base superalloys.

Tien, J. K.↗
NASA NTRS1983

The NASTRAN user's manual

All information directly associated with problem solving using the NASTRAN program is presented. This structural analysis program uses the finite element approach to structural modeling wherein the distributed finite properties of a structure are represented by a finite element of structural elements which are interconnected at a finite number of grid points, to which loads are applied and for which displacements are calculated. Procedures are described for defining and loading a structural model. Functional references for every card used for structural modeling, the NASTRAN data deck and control cards, problem solution sequences (rigid formats), using the plotting capability, writing a direct matrix abstraction program, and diagnostic messages are explained. A dictionary of mnemonics, acronyms, phrases, and other commonly used NASTRAN terms is included.

Source record↗