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  • Other Sources  (967)
  • AERODYNAMICS  (479)
  • SOLAR PHYSICS  (310)
  • NONMETALLIC MATERIALS  (178)
  • Biochemistry and Biotechnology
  • Inorganic Chemistry
  • 1980-1984  (967)
  • 1925-1929
  • 1983  (967)
Collection
Source
Keywords
Years
  • 1980-1984  (967)
  • 1925-1929
Year
  • 1
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    Viscous wing code development: A 3-D viscid-inviscid interactive analysis (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: NASA. Langley Research Center, Theoretical Aerodynamics Contractors' Workshop, Volume 2; p 607-63
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  • 2
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    Computation of separated flow on airfoils with the Grumfoil code (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: NASA. Langley Research Center, Theoretical Aerodynamics Contractors' Workshop, Volume 2; p 557-58
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  • 3
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    Analysis of airfoil transitional separation bubbles (1983)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: NASA. Langley Research Center, Theoretical Aerodynamics Contractors' Workshop, Volume 2; p 539-55
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  • 4
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    Entropy effects and shock fitting in conical supersonic full potential flows (1983)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: NASA. Langley Research Center, Theoretical Aerodynamics Contractors' Workshop, Volume 2; p 461-49
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  • 5
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    Surface crystallization of a fluoride glass (1983)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: Growth of crystals on the surface of a Zr-Ba-La fluoride glass was observed by optical and scanning electron microscopy. Small, dark crystal nucleated rapidly and grew to a size of about 10 microns; then they stopped growing, and wrinkled regions emerged, covering the entire crystal surface.
    Keywords: NONMETALLIC MATERIALS
    Type: American Ceramic Society, Communications (ISSN 0002-7820); 66; C-132
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  • 6
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    Report on the Workshop on Intercomparison of Solar UV Irradiance Measurements and Related Instrument Calibration (1983)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The knowledge of the absolute value of the solar ultraviolet irradiance did not improve very much during the rising phase of the solar cycle 21. The variations associated with the solar rotation period were observed by means of three satellites, namely, the Atmospheric Explorer E (AE-E), Nimbus 7 and the Solar Mesospheric Explorer (SME). Long-term variations related to the solar activity cycle are not well known. Values were deduced during the solar cycle 21 from the AE-E satellite and the rocket program performed by the Laboratory for Atmospheric and Space Physics leading to variations of about a factor of 2 around 150 nm but definitely less than 20 percent beyond 175 nm. Such low level of variation is still masked by the current uncertainties and reproducibility of the observations performed since 1976. The uncertainties of recent observations are reported with their discrepancies. The gaps between the current accuracy goals and the achievements are still very important. The challenge for the next three years is to improve both the accuracy and the precision of future observations at the level of the available irradiance standards and to measure quantitatively long-term variations of the order of a few percent. The main causes of these gaps are identified.
    Keywords: SOLAR PHYSICS
    Type: International Council of Scientific Unions Middle Atmosphere Program. Handbook for MAP, Vol. 8; p 45-51
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  • 7
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    Electrodynamic coupling in magnetically confined stellar X-ray loops (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The solar coronal complex X-ray structure is now known to involve radiation loops that coincide spatially with the magnetic loops confining the radiating plasma. An effort is presently made to identify primary submodels involved in the global coupling between a mechanical energy reservoir of beta value greater than 1 and a contiguous site of X-ray activity whose beta value is lower than 1. The 'dynamo' model invoked establishes a quantitative connection between mechanical driver properties and the dimensions, field strength, and number density distribution of elemental magnetic loops.
    Keywords: SOLAR PHYSICS
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  • 8
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    Thermal oxidative degradation reactions of linear perfluoroalkyl ethers (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Thermal and thermal oxidative stability studies were performed on linear perfluoroalkyl ether fluids. The effect on degradation by metal catalysts and degradation inhibitors is reported. The linear perfluoroalkyl ethers are inherently unstable at 316 C in an oxidizing atmosphere. The metal catalysts greatly increased the rate of degradation in oxidizing atmospheres. In the presence of these metals in an oxidizing atmosphere, the degradation inhibitors were highly effective in arresting degradation at 288 C. However, the inhibitors had only limited effectiveness at 316 C. The metals promote degradation by chain scission. Based on elemental analysis and oxygen consumption data, the linear perfluoroalkyl ether fluids have a structural arrangement based on difluoroformyl and tetrafluoroethylene oxide units, with the former predominating. Previously announced in STAR as N82-26468
    Keywords: NONMETALLIC MATERIALS
    Type: I&EC - Industrial and Engineering Chemistry, Product Research and Development (ISSN 0196-4321); 22; 166-170
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  • 9
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    Fracture mechanics of cellular glass (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The fracture mechanics of cellular glasses (for the structural substrate of mirrored glass for solar concentrator reflecting panels) are discussed. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials were developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region 1 may be slower, by orders of magnitude, than that found in dense glasses. Previously announced in STAR as N82-11209
    Keywords: NONMETALLIC MATERIALS
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  • 10
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    Simulated space radiation effects on dielectrics and coatings (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Simulation tests of space radiation have been performed for specific organic and inorganic materials. The test results for fifteen materials exposed to protons and five exposed to electrons are presented.
    Keywords: NONMETALLIC MATERIALS
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); NS-30; 4090-409
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  • 11
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    The effect of annealing on the creep of plasma-sprayed ceramics (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The creep of plasma sprayed ZrO2-8Y2O3 was measured at temperatures from 98 to 1250 C (180 to 220 F), and compared to creep of identical samples after annealing at temperatures from 98 to 1316 C (1800 to 2400 F). Loads and temperatures which produced significant creep of as sprayed ceramics produced no creep after annealing. Previously announced in STAR as N83-24799
    Keywords: NONMETALLIC MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 819-827
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  • 12
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    Residual stress in plasma-sprayed ceramic turbine tip and gas-path seal specimens (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The residual stresses in a ceramic sheet material used for turbine blade tip gas path seals, were estimated. These stresses result from the plasma spraying process which leaves the surface of the sheet in tension. To determine the properties of plasma sprayed ZrO2-Y2O3 sheet material, its load deflection characteristics were measured. Estimates of the mechanical properties for sheet materials were found to differ from those reported for plasma sprayed bulk materials. Previously announced in STAR as N83-28380
    Keywords: NONMETALLIC MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 802-809
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  • 13
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    Correlation of compressive and shear stress with spalling of plasma-sprayed ceramic materials (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Ceramics on metal substrates for potential use as high temperature seals or other applications are exposed to forces originating from differences in thermal expansion between the ceramic and the metal substrate. This report develops a relationship between the difference in expansion of the ceramic and the substrate, defines conditions under which shear between the ceramic and the substrate occurs, and those under which bending forces are produced in the ceramic. The off-axis effect of compression forces resulting from high temperature plastic flow of the ceramic producing buckling of the ceramic is developed. Shear is associated with the edge or boundary stresses on the component while bending is associated with the distortion of an interior region. Both modes are significant in predicting life of the ceramic. Previously announced in STAR as N83-27016
    Keywords: NONMETALLIC MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 810-818
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  • 14
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    An exploratory study of area-efficient vortex flap concepts (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The potential of planform modification and hinge-line relocation to improve the thrust efficiency of vortex flaps was experimentally investigated on a 60-deg cropped delta wing model. Spanwise segmentation of the flap, together with chord-tailoring of the segments, allowed the vortex to be maintained on the outboard flap surfaces to higher angles of attack. In addition, location of the flap hinge aft of and underneath the wing leading edge generated substantial thrust from the vortex suction acting on the leading-edge lower surface. A combination of these beneficial effects allowed the flap/wing area to be reduced from 11.4 percent of the continuous flap to 6.3 percent of segmented flap, essentially without detriment to the incremental lift-to-drag ratio due to flap addition in the lift coefficient range 0.5-0.7 based on the basic wing area.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 20; 1062-106
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  • 15
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    Observations and implications of natural laminar flow on practical airplane surfaces (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 20, p. 3138, Accession no. A82-40893
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 20; 993-1006
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  • 16
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    Interpretation of vector magnetograph data including magneto-optic effects. I - Azimuth angle of the transverse field (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: In this paper, the presence of Faraday rotation in measurements of the orientation of a sunspot's transverse magnetic field is investigated. Using observations obtained with the Marshall Space Flight Center's (MSFC) vector magnetograph, the derived vector magnetic field of a simple, symmetric sunspot is used to calculate the degree of Faraday rotation in the azimuth of the transverse field as a function of wavelength from analytical expressions for the Stokes parameters. These results are then compared with the observed rotation of the field's azimuth which is derived from observations at different wavelengths within the Fe I 5250 A spectral line. From these comparisons, it is found: the observed rotation of the azimuth is simulated to a reasonable degree by the theoretical formulations if the line-formation parameter is varied over the sunspot; these variations are substantiated by the line-intensity data; for the MSFC system, Faraday rotation can be neglected for field strengths less than 1800 G and field inclinations greater than 45 deg; to minimize the effects of Faraday rotation in sunspot umbrae, MSFC magnetograph measurements must be made in the far wings of the Zeeman-sensitive spectral line.
    Keywords: SOLAR PHYSICS
    Type: Solar Physics (ISSN 0038-0938); 88; 51-64
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  • 17
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    Ultrasonic mixing of epoxy curing agents (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A new technique for mixing solid curing agents into liquid epoxy resins using ultrasonic energy was developed. This procedure allows standard curing agents such as 4,4 prime-diaminodiphenyl sulfone (4,4 prime-DDS) and its 3,3 prime-isomer, (3,3 prime-DDS) to be mixed without prior melting of the curing agent. It also allows curing agents with very high melt temperatures such as 4,4 prime-diaminodiphenyl sulfone (4,4 prime-DDS) and its 3,3 prime-isomer, (3,3 prime-DDS) to be mixed without prior melting of the curing agent. It also allows curing agents with very high melt temperatures such as 4,4 prime-diaminobenzophenone (4,4 prime-DABP) (242 C) to be mixed without premature curing. Four aromatic diamines were ultrasonically blended into MY-720 epoxy resin. These were 4, 4 prime-DDS; 3,3 prime-DDA; 4, 4 prime-DABP and 3,3 prime-DABP. Unfilled moldings were cast and cured for each system and their physical and mechanical properties compared. Previously announced in STAR as N83-27018
    Keywords: NONMETALLIC MATERIALS
    Type: SAMPE Quarterly (ISSN 0036-0821); 14; 46-50
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  • 18
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    Dynamics of a surge observed in the C IV and H alpha lines (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Time sequences of a surge have been obtained in Active Region 2701 during a coordinated SMY program, on October 2nd, 1980, while the MSDP spectrograph operated in H-alpha at the Meudon Solar Tower and the UVSP spectrometer on SMM observed in the 1548 A C IV resonance line. The cold (H-alpha) and hot (C IV) material follow the same channel, and the event lasts about 10 min in both lines. A good correlation is found between H-alpha and C IV velocities; radial velocities along the surge are in the range 40-60 km/s in both cases. The observations are consistent with the hypothesis that a pressure gradient drives the surge. The H-alpha data seem to indicate the presence of a shock wave in the chromosphere, while the C IV quantities (velocities, accelerations) vary on a very short time scale. Their maxima occur at some locations which could be interpreted as 'pinched' zones.
    Keywords: SOLAR PHYSICS
    Type: Astronomy and Astrophysics (ISSN 0004-6361); 127; 2, No; 337-344
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  • 19
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    Hardness of dense beta-Si3N4 (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The effects of small changes in the concentration of an oxygen content densification aid on the room temperature microhardness of hot isostatically pressed and sintered beta-Si3N4 ceramics are studied. The compositions studied were Si3N4 containing 7 wt. pct BeSiN2, a fixed nonoxide densification aid, and 1.9-3.7 wt. pct oxygen as a second, variable densification aid. A proportional relationship between high density and high oxygen content, regardless of heat treatment type, is noted.
    Keywords: NONMETALLIC MATERIALS
    Type: Journal of Materials Science Letters (ISSN 0261-8028); 2; 657-659
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  • 20
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    Stability of shock waves attached to wedges and cones (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 06, p. 799, Accession no. A82-17876
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 21; 1611-161
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  • 21
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    Stability of silica heat shield materials in the Space Shuttle environment (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Sample tiles of Space Shuttle reusable surface insulation (RSI) and fibrous refractory composite insulation (FRCI) have been alternately exposed to simulated mission heating and the Kennedy Space Center launch-pad environment for up to 50 cycles. The two types of tiles were coated with an identical glass composition. The coating on RSI tiles was prone to cracking in the test environment while the same coating on FRCI was not. Absorption of water contaminated with environmental deposits resulted in accelerated devitrification in the RSI tiles. Devitrification in FRCI tiles was significantly less. The rate of environmental degradation of tiles appeared to be dependent on the amount of water absorption.
    Keywords: NONMETALLIC MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 564-577
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  • 22
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    Surface chemistry, friction, and wear of Ni-Zn and Mn-Zn ferrites in contact with metals (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: X-ray photoelectron and Auger electron spectroscopy analysis were used in sliding friction experiments. These experiments were conducted with hot-pressed polycrystalline Ni-Zn and Mn-Zn ferrites, and single-crystal Mn-Zn ferrite in contact with various transition metals at room temperature in both vacuum and argon. The results indicate that Ni2O3 and Fe3O4 were present on the Ni-Zn ferrite surface in addition to the nominal bulk constituents, while MnO2 and Fe3O4 were present on the Mn-Zn ferrite surface in addition to the nominal bulk constituents. The coefficients of friction for the ferrites in contact with metals were related to the relative chemical activity of these metals. The more active the metal, the higher is the coefficient of friction. The coefficients of friction for the ferrites were correlated with the free energy of formation of the lowest metal oxide. The interfacial bond can be regarded as a chemical bond between the metal atoms and the oxygen anions in the ferrite surfaces. The adsorption of oxygen on clean metal and ferrite does strengthen the metal-ferrite contact and increase the friction. The ferrites exhibit local cracking and fracture with sliding under adhesive conditions. All the metals transferred to the surfaces of the ferrites in sliding. Previously announced in STAR as N83-19901
    Keywords: NONMETALLIC MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 674-693
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  • 23
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    Shrinkage of amorphous silica fibers (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: By the application of a new technique, the viscosity of amorphous silica fibers was determined in the 1100-1350 C temperature range. An equation was derived that describes the kinetics of shrinkage of the fibers in terms of their radius, viscosity, and surface tension.
    Keywords: NONMETALLIC MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 492-501
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  • 24
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    Phase distributions in plasma-sprayed zirconia-yttria (1983)
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    Publication Date: 2011-08-18
    Description: The distribution of phases in plasma-sprayed zirconia-yttria has been determined over a range of yttria levels from 0 to 26.1 molpct YO(1.5) using room temperature X-ray diffractometry. Pure, plasma-sprayed zirconia is composed almost entirely of the monoclinic phase. At levels of yttria between 4 and 10 percent, a quenched-in tetragonal phase predominates, and at higher levels the cubic phase predominates. The phase distributions are compared with previously reported test lives of thermal barrier coatings formed from these materials. Regions of optimal lives were found to correlate with regions having high amounts of the tetragonal phase, small but nonzero amounts of the monoclinic phase, and little or none of the cubic phase. Possible relationships between phase composition and coating performance are discussed.
    Keywords: NONMETALLIC MATERIALS
    Type: American Ceramic Society Bulletin (ISSN 0002-7812); 62; 1355-135
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  • 25
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    Differences in the temporal variations of solar UV flux, 10.7-cm solar radio flux, sunspot number, and Ca-K plage data caused by solar rotation and active region evolution (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Attention is given to two types of temporal variations in the solar UV spectral irradiance caused by solar rotation and active region evolution. It is noted that the first type of dissimilar temporal behavior occurs when concentrations of solar active regions evolve at solar longitudes nearly 180 deg apart. Both the UV observations and modeled UV fluxes based on Ca-K plage data then exhibit pronounced 13-day periodicity, whereas the 10.7-cm solar radio flux and sunspot number exhibit quite dissimilar temporal variations. This type of dissimilarity is related to the modeled UV flux and has a dependence on the solar central meridian distance that is narrower than that for the 10.7-cm radio flux or for sunspot numbers. A second case of marked dissimilarity is seen when major new solar active regions arise and dominate the full-disk fluxes for several rotations. It is found that the strongest peaks in 10.7 cm and sunspot numbers tend to occur on their first rotation, for example, during major dips in the total solar irradiance, whereas the Ca-K plages and UV enhancements peak on the next rotation and then decay more slowly on subsequent rotations.
    Keywords: SOLAR PHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 9883-988
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  • 26
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    Development of plane strain fracture toughness test for ceramics using Chevron notched specimens (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Chevron-notched four-point-bend and short-bar specimens have been used to determine the fracture toughness of sintered aluminum oxide and hot-pressed silicon nitride ceramics. The fracture toughness for Si3N4 is found to be essentially independent of the specimen size and chevron notch configuration, with values ranging from 4.6 to 4.9 MNm exp -3/2. In contrast, significant specimen size and notch geometry effects have been observed for Al2O3, with the fracture toughness ranging from 3.1 to 4.7 MNm exp -3/2. These effects are attributed to a rising crack growth resistance curve for the Al2O3 tested.
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  • 27
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    A chimera grid scheme (1983)
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    Publication Date: 2011-08-18
    Description: A mesh system composed of multiple overset body-conforming grids is described for adapting finite-difference procedures to complex aircraft configurations. In this so-called 'chimera mesh,' a major grid is generated about a main component of the configuration and overset minor grids are used to resolve all other features. Methods for connecting overset multiple grids and modifications of flow-simulation algorithms are discussed. Computational tests in two dimensions indicate that the use of multiple overset grids can simplify the task of grid generation without an adverse effect on flow-field algorithms and computer code complexity.
    Keywords: AERODYNAMICS
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  • 28
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    The stability of coronal loops - Finite-length and pressure-profile limits (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Results are described from a quickly converging, necessary-and-sufficient, MHD-stability test for coronal-loop models. The primary stabilizing influence arises from magnetic line tying at the photosphere, and this end conditions requires a series expansion of possible loop excitations. The stability boundary is shown to quickly approach a limit as the number of terms increases, providing a critical length for the loop in proportion to its transverse magnetic scale. Several models of force-free-field profiles are tested and the stability behavior of a localized current channel, embedded in an external current-free region, is shown to be superior to that of other, broader, current profiles. Pressure-gradient effects, leading to increased or decreased stability, are shown to be amplified by line tying. Long loops must either conduct low net current, or exhibit an axial-field reversal coexisting with a low-pressure core. The limits on stability depend on the magnetic aspect ratio, the plasma-to-magnetic pressure ratio, and the field orientation at the loop edge. Applications of these results to the structure of coronal loops are described.
    Keywords: SOLAR PHYSICS
    Type: Solar Physics (ISSN 0038-0938); 88; 163-177
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  • 29
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    Microstructural characterization of SiC (SCS) filaments (1983)
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    Publication Date: 2011-08-18
    Description: Microstructural features of SiC('SCS') fibers demonstrating growth properties have been investigated using scanning and transmission electron microscopy. An etchant of fused KOH:KNO3 was developed which adequately brought out previously undetermined features.
    Keywords: NONMETALLIC MATERIALS
    Type: SAMPE Quarterly (ISSN 0036-0821); 14; 39-45
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  • 30
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    Implications of high-energy neutron observations from solar flares (1983)
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    Publication Date: 2011-08-18
    Description: The time-dependent flux of high-energy neutrons discovered from the solar flare of 1980 June 21 provides a new technique for determining the total number and energy spectrum of accelerated protons and nuclei at the sun. The implications of these observations on gamma-ray emission, relativistic electron spectrum and number, proton and electron energy contents, and the location of the interaction region are also examined.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 273; L41-L45
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  • 31
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    Fluid motions in the solar chromosphere-corona transition region. IV - Mass motions over sunspot umbrae (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 273; 374-380
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  • 32
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    Solar irradiance variations. II - Analysis of the extreme ultraviolet measurements onboard the Atmosphere Explorer E satellite (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Five of the extreme ultraviolet channels (L-alpha, L-beta, He I, He II, Fe XV) measuring irradiance fluctuations on board the AE-E satellite between 1977 and 1980 have been studied in detail. It is shown that the daily variations correspond very closely to the daily variations in solar radio emission (F10.7), but that the UV data are afflicted with serious and to date unrecognized calibration changes during the period of operation of the instruments. In order to correct for these changes, a statistical analysis is carried out, and a set of corrections to the raw data is suggested. The resulting, now uniform, data are then compared with rocket measurements (L-alpha) and data acquired onboard the AE-C satellite (L-beta). Finally the remaining discrepancies are discussed. After concluding that they are below the overall level of uncertainties, a first-order 10-year run of EUV irradiances derived from F10.7 data is proposed. This estimate includes the ratio of irradiance levels between the maxima of solar cycles 20 and 21 and the intervening minimum.
    Keywords: SOLAR PHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 9037-905
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    Determining the solar wind speed above active regions using remote radio-wave observations (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A new technique has made it possible to measure the velocity of portions of the solar wind during its flow outward from the sun. This analysis utilizes spacecraft (ISEE-3) observations of radio emission generated in regions of the solar wind associated with solar active regions. By tracking the source of these radio waves over periods of days, it is possible to measure the motion of the emission regions. Evidence of solar wind acceleration during this outward flow, consistent with theoretical models, has also been obtained.
    Keywords: SOLAR PHYSICS
    Type: Science (ISSN 0036-8075); 222; 506-508
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  • 34
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    Conservative full-potential calculations for axisymmetric, transonic flow (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 17, p. 2873, Accession no. A81-38082
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 21; 1492-149
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  • 35
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    Hydromagnetic waves, turbulence, and collisionless processes in the interplanetary medium (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: An extended discussion is conducted concerning the origin and evolution of interplanetary hydromagnetic waves and turbulence, and their influence on the large scale dynamics of the solar wind. The solar wind is at present the preeminent medium for the study of hydromagnetic waves and turbulence, providing an opportunity for advancement of understanding of the most fundamental processes of the astrophysical plasmas. All interplanetary fluctuations whose time scale is observed to be greater than 1 sec can be regarded as hydromagnetic fluctuations. It has been found to be simplest, and generally very satisfactory, to model interplanetary variations as fluctuations in an MHD fluid. Attention is given to the classification of wave modes, geometrical hydromagnetics, Alfven wave pressure, rugged invariants, and the kinetic theory of collisionless processes.
    Keywords: SOLAR PHYSICS
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  • 36
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    Study of molecular deformation mechanisms in the glassy state. I - Temperature effect on stress-birefringence and strain-birefringence responses of poly(methyl methacrylate) (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Keywords: NONMETALLIC MATERIALS
    Type: Journal of Polymer Science: Polymer Physics Edition (ISSN 0098-1273); 21; 1647-166
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  • 37
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    Electrically conductive black optical paint (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: An electrically conductive flat black paint has been developed for use on the Galileo spacecraft which will orbit Jupiter in the late 1980s. The paint, designed for equipment operating in high-energy radiation fields, has multipurpose functions. Its electrical conductivity keeps differential charging of the spacecraft external surfaces and equipment to a minimum, preventing the buildup of electrostatic fields and arcing. Its flat black aspect minimizes the effects of stray light and unwanted reflectances, when used in optical instruments and on sunshades. Its blackness is suitable, also, for thermal control, when the paint is put on spacecraft surfaces. The paint has good adherence properties, as measured by tape tests, when applied properly to a surface. The electrically conductive paint which was developed has the following characteristics: an electrical resistivity of 5 x 10 to the 7th ohms per square; a visual light total reflectance of approximately 5 percent; an infrared reflectance of 0.13 measured over a spectrum from 10 to the (-5.5) power to 0.001 meter; a solar absorptivity, alpha-s, of 0.93, and a thermal emissivity, epsilon, of 0.87, resulting in an alpha-s/epsilon of 1.07. The formula for making the paint and the process for applying it are described.
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  • 38
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    Characteristics of Si3N4-SiO2-Ce2O3 compositions sintered in high-pressure nitrogen (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Full-density Si3N4-SiO2-Ce2O3 compositions were prepared by sintering with 2.5 MPa nitrogen pressure at temperatures of 1900 and 2090 C. Room-temperature flexural strengths near 700 MPa for sintered material compared favorably with the strength of hot-pressed material. At 1370 C, where flexural strengths as high as 363 MPa were obtained, it was observed that the coarsest structure was the strongest and the finest structure was the weakest. One of the compositions tested, Si3N4-8.7 wt pct SiO2-8.3 wt pct-Ce2O3, was found to have excellent 200-h oxidation resistance at 700, 1000, and 1370 C, without incidence of 700 to 1000 C phase instability and cracking.
    Keywords: NONMETALLIC MATERIALS
    Type: American Ceramic Society, Journal (ISSN 0002-7820); 66; 835-841
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  • 39
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    Molecular deformation and stress-strain behavior of poly(bisphenol-A-diphenyl sulfone) (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The strain-birefringence response of poly(bisphenol-A-diphenyl sulfone) is found to be independent of temperature at temperatures below -100 C; at higher temperatures, the response becomes slightly dependent on temperature, with lower birefringence seen at higher temperatures. The stress-strain behavior and the stress-birefringence response both depend on temperature over the entire testing temperature range (-179 C to 150 C) studied; this dependence, however, is not pronounced. The evidence is seen as suggesting that the polymer molecules respond to deformation by undergoing conformational rearrangements; the mode of the molecular deformation remains unchanged for temperatures of -100 C or lower. At higher temperatures, the average length of the chain segments involved in the rearrangement increases. The stress-strain response is attributed mainly to chain orientation. The entropic contribution deriving from chain orientation at temperatures below -100 C is still substantial. The modest temperature dependence of the stress-strain response suggests that the energy barriers for the chain segments involved in the rearrangement are relatively low.
    Keywords: NONMETALLIC MATERIALS
    Type: Journal of Applied Physics (ISSN 0021-8979); 54; Oct. 198
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  • 40
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    Behavior of transition-region lines during impulsive solar flares (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The emissions observed in lines originating in the transition-region plasma, particularly during impulsive flares, are investigated using data collected by the Ultraviolet Spectrometer and Polarimeter on the Solar Maximum Mission. Data concerning lines from ions such as Si II, C IV, Si IV, O V, and Fe XXI are analyzed. Topics examined include the transition region away from sunspots, oscillatory motions above sunspots, the shape of the transition region, the transition region during flares, and O V and Fe XXI during flare flash phases.
    Keywords: SOLAR PHYSICS
    Type: (ISSN 0038-0938)
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  • 41
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    Gamma-ray lines and neutrons from solar flares (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The energy spectrum of accelerated protons and nuclei at the site of a limb flare was derived by a technique, using observations of the time dependent flux of high energy neutrons at the earth. This energy spectrum is very similar to the energy spectra of 7 disk flares for which the accelerated particle spectra was previously derived using observations of 4 to 7 MeV to 2.223 MeV fluence ratios. The implied spectra for all of these flares are too steep to produce any significant amount of radiation from pi meson decay. It is suggested that the observed 10 MeV gamma rays from the flare are bremsstrahlung of relativistic electrons. Previously announced in STAR as N83-19695
    Keywords: SOLAR PHYSICS
    Type: (ISSN 0038-0938)
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  • 42
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    A comparison of coronal and interplanetary current sheet inclinations (1983)
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    Publication Date: 2011-08-18
    Description: The HAO white light K-coronameter observations show that the inclination of the heliospheric current sheet at the base of the corona can be both large (nearly vertical with respect to the solar equator) or small during Cararington rotations 1660 - 1666 and even on a single solar rotation. Voyager 1 and 2 magnetic field observations of crossing of the heliospheric current sheet at distances from the sun of 1.4 and 2.8 AU. Two cases are considered, one in which the corresponding coronameter data indicate a nearly vertical (north-south) current sheet and another in which a nearly horizontal, near equatorial current sheet is indicated. For the crossings of the vertical current sheet, a variance analysis based on hour averages of the magnetic field data gave a minimum variance direction consistent with a steep inclination. The horizontal current sheet was observed by Voyager as a region of mixed polarity and low speeds lasting several days, consistent with multiple crossings of a horizontal but irregular and fluctuating current sheet at 1.4 AU. However, variance analysis of individual current sheet crossings in this interval using 1.92 see averages did not give minimum variance directions consistent with a horizontal current sheet. Previously announced in STAR as N83-31566
    Keywords: SOLAR PHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; Oct. 1
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  • 43
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    Photothermal degradation of ethylene/vinylacetate copolymer (1983)
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    Publication Date: 2011-08-18
    Description: Photothermal degradation studies were conducted on a 'stabilized' formulation of ethylene/vinyl acetate copolymer (EVA) in the temperature range 25-105 C under three different oxygen environments (in open air, with limited access to O2, and in a dark closed stagnant oven). These studies were performed in order to evaluate the utility of EVA as an encapsulation material for photovoltaic modules. Results showed that at low temperature (25 C), slow photooxidation of the polymer occurred via electronic energy transfer involving the UV absorber incorporated in the polymer. However, no changes in the physical properties of the bulk polymer were detected up to 1500 hours of irradiation. At elevated temperatures, leaching and evaporation of the additives occurred, which ultimately resulted in the chemical crosslinking of the copolymer and the formation of volatile photoproducts such as acetic acid.
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  • 44
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    The solar O III spectrum. II - Longer wavelengths, line widths, and the He II Lyman alpha radiation field (1983)
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    Publication Date: 2011-08-18
    Description: The solar O III spectrum above 900 A is analyzed, including several visible and infrared lines which are important in nebular studies. The dependence of the line intensities on the rate of photoexcitation by He Ly-alpha is determined, and the observability of these lines in the solar spectrum is studied. The impact approximation is employed to calculate the expected line widths of the stronger solar O III lines. The photoexciting field at 304 A calculated from the observed intensities of the O III lines below 900 A (Bhatia et al., 1982) is compared with the field predicted by a recent model (Avrett et al., 1976). It is shown that additional radiation trapping must be present beyond that given by this model.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal Supplement Series (ISSN 0067-0049); 53; Sept
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  • 45
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    Measurements on a shock wave generated by a solar flare (1983)
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    Publication Date: 2011-08-18
    Description: It is shown that path-integrated radio-scattering measurements of the solar wind velocity yield higher estimates than those of point measurements. The post-shock speed is determined from radio scattering measurements by selection of the maximum of the radio-scattering deduced from the velocity-time curve, whereas velocity points on the rising edge of the shock underestimate the post-shock gas velocity, and therefore the shock speed. However, it is suggested that large uncertainties reside in using radio techniques for measurements of parameters of the shock wave, and the uncertainties may be large enough to encompass the lower velocity values calculated by a point method of measurement.
    Keywords: SOLAR PHYSICS
    Type: Nature (ISSN 0028-0836); 304; Aug. 25
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  • 46
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    The structure of boron in boron fibres (1983)
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    Publication Date: 2011-08-18
    Description: The structure of noncrystalline, chemically vapour-deposited boron fibres was investigated by computer modelling the experimentally obtained X-ray diffraction patterns. The diffraction patterns from the models were computed using the Debye scattering equation. The modelling was done utilizing the minimum nearest-neighbour distance, the density of the model, and the broadening and relative intensity of the various peaks as boundary conditions. The results suggest that the fibres consist of a continuous network of randomly oriented regions of local atomic order, about 2 nm in diameter, containing boron atoms arranged in icosahedra. Approximately half of these regions have a tetragonal structure and the remaining half a distorted rhombohedral structure. The model also indicates the presence of many partial icosahedra and loose atoms not associated with any icosahedra. The partial icosahedra and loose atoms indicated in the present model are in agreement with the relaxing sub-units which have been suggested to explain the anelastic behavior of fibre boron and the loosely bound boron atoms which have been postulated to explain the strengthening mechanism in boron fibres during thermal treatment.
    Keywords: NONMETALLIC MATERIALS
    Type: Journal of Materials Science (ISSN 0022-2461); 18; Sept
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  • 47
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    Solar radius change between 1925 and 1979 (1983)
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    Publication Date: 2011-08-18
    Description: From an analysis of numerous reports from different locations on the duration of totality of the solar eclipses on January 24, 1925, and February 26, 1979, it is found that the solar radius at the earlier date was 0.5 arcsec (or 375 km) larger than at the later date. The correction to the standard solar radius found for each eclipse is different when different subsets of the observations are used (for example, edge of path of totality timings compared with central timings). This is seen as suggesting the existence of systematic inaccuracies in our knowledge of the lunar figure. The differences between the corrections for both eclipses, however, are very similar for all subsets considered, indicating that changes of the solar size may be reliably inferred despite the existence of the lunar figure errors so long as there is proper consideration of the distribution of the observations. These results are regarded as strong evidence in support of the occurrence of solar radius changes on shorter than evolutionary time scales.
    Keywords: SOLAR PHYSICS
    Type: Nature (ISSN 0028-0836); 304; Aug. 11
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  • 48
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    Solar oscillations with 13-day period (1983)
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    Publication Date: 2011-08-18
    Description: Reference is made to the solar observations made by Claverie et al. (1982) over a three-month period in the summer of 1981 which show oscillatory velocity with a period of 13.1 days and amplitude of 6.6 m/s. These investigators reject the possibility that they see the Doppler shift from a radial oscillation, because the amplitude is implausibly large. They also do not believe that their signal was induced by solar magnetic fields, since typical mean solar fields are too small. Photo-electric drift-scan measurements of the solar diameter and full-disk magnetograms taken at Kitt Peak National Observatory are examined here for evidence of variations corresponding to the velocity oscillations of the 13.1-day period. An upper limit on radius variations is reported which is a factor of six below the amplitude needed to explain the velocity observations as a radial oscillation. Attention is also given to the possible role of the rotation of large-scale surface magnetic features.
    Keywords: SOLAR PHYSICS
    Type: Nature (ISSN 0028-0836); 304; Aug. 11
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  • 49
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    Injection slot location for boundary-layer control in shock-induced separation (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 18, p. 726, Accession no. A78-41866
    Keywords: AERODYNAMICS
    Type: (ISSN 0021-8669)
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  • 50
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    Lower-curing-temperature PMR polyimides (1983)
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    Publication Date: 2011-08-18
    Description: Partial substitution of a p-aminostyrene end-cap for the monomethyl ester of 5-norbornene-2, 3-dicarboxylic acid lowered the final cure temperature of typical PMR resins from 600 F to 500 F. The weight loss characteristics of neat resins and graphite fiber composites prepared by using the mixed end-cap approach were determined at 600 F. The room temperature and short-time elevated temperature mechanical properties of the composites at 550 F and 600 F were determined. The mechanical property retention characteristics of the composites at 550 F and 600 F are discussed. Previously announced in STAR as N83-10118
    Keywords: NONMETALLIC MATERIALS
    Type: Polymer Composites (ISSN 0272-8397); 4; July 198
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  • 51
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    Dynamic fatigue of a machinable glass-ceramic (1983)
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    Publication Date: 2011-08-18
    Description: To assess the stress-corrosion susceptibility of a machinable glass-ceramic, its dynamic fatigue behavior was investigated by measuring its strength as a function of stress rate. Fracture mechanics techniques were used to analyze the results for the purpose of making lifetime predictions for components of this material. This material was concluded to have only moderate resistance (N = 30) to stress corrosion in ambient conditions. The effects of specimen size on strength were assessed for the material used in this study; it was concluded that the Weibull edge-flaw scaling law adequately describes the observed strength-size relation.
    Keywords: NONMETALLIC MATERIALS
    Type: (ISSN 0002-7820)
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  • 52
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    Experimental determination of vapor species from laser-ablated carbon phenolic composites (1983)
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    Publication Date: 2011-08-18
    Description: Previosuly cited in issue 17, p. 2910, Accession no. A81-39069
    Keywords: NONMETALLIC MATERIALS
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  • 53
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    Formation of the Cl I line at 1351 A in the solar chromosphere (1983)
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    Publication Date: 2011-08-18
    Description: The formation of the multiplet containing the Cl I 1351 A line is investigated due to the unusual brightness of this line. It is determined that this line is formed via a fluorescence effect driven by the 1335 A line of C II. Non-LTE calculations including this effect are found to agree with the observed line intensity. It is shown that the 1347 and 1363 A lines of Cl I do not benefit from this effect and they are predicted to be approximately 100 times weaker.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal; vol. 266
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  • 54
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    Observations of solar oscillations of low and intermediate degree (1983)
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    Publication Date: 2011-08-18
    Description: Measurements are presented of solar velocity oscillations with spherical harmonic degree 1-139 and angular order approximately 0. With an amplitude sensitivity of approximately 2 cm/s, trapped acoustic wave modes of radial orders 2-26 are observed at frequencies between 1.7 and 5.5 mHz. The radial order identifications of low-degree modes previously inferred from theory are confirmed. Only marginal evidence of long-period, gravity-mode oscillations is found.
    Keywords: SOLAR PHYSICS
    Type: Nature; 302; Mar. 3
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  • 55
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    Magnetic canopies in unipolar regions (1983)
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    Publication Date: 2011-08-18
    Description: Base-height statistics are presented for magnetic canopies in six unipolar magnetic regions which were observed near the limb with the Kitt Peak Vacuum Telescope and Diode Array Magnetograph during the period 25 April-3 July, 1980. As in earlier studies, extensive areas are found to be covered by low-lying canopies.
    Keywords: SOLAR PHYSICS
    Type: Solar Physics (ISSN 0038-0938); 87; Aug. 198
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  • 56
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    Corotating pressure waves without fast streams in the solar wind (1983)
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    Publication Date: 2011-08-18
    Description: Voyager 1 and 2 magnetic field and plasma data are presented which demonstrate the existence of large scale, corotating, non-linear pressure waves between 2 AU and 4 AU that are not accompanied by fast streams. The pressure waves are presumed to be generated by corotating streams near the sun. For two of the three pressure waves that are discussed, the absence of a stream is probably a real, physical effect, viz., a consequence of deceleration of the stream by the associated compression wave. For the third pressure wave, the apparent absence of a stream may be a geometrical effect; it is likely that the stream was at latitudes just above those of the spacecraft, while the associated shocks and compression wave extended over a broader range of latitudes so that they could be observed by the spacecraft. It is suggested that the development of large-scale non-linear pressure waves at the expense of the kinetic energy of streams produces a qualitative change in the solar wind in the outer heliosphere. Within a few AU the quasi-stationary solar wind structure is determined by corotating streams whose structure is determined by the boundary conditions near the sun. Previously announced in STAR as N83-19694
    Keywords: SOLAR PHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; Aug. 1
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  • 57
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    Surface analyses of carbon fibers produced from polyacrylonitrile fibers at low carbonization temperatures (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A process for producing carbon fibers from polyacrylonitrile at low carbonization temperatures was studied. The bulk and surface properties of fibers obtained after reaction with benzoic acid, air and carbonizing in nitrogen or a dilute acetylene atmosphere are discussed. All fiber products had different surface and internal compositions. Samples produced at temperatures up to 950 C and carbonized in nitrogen contained substantial quantities of nitrogen and oxygen at the surface. During carbonization, the surface nitrogen converted into two new forms, possibly nitrile and an azo or a new carbon-nitrogen bond. Samples carbonized in acetylene contained a carbon-rich surface stable to oxidation.
    Keywords: NONMETALLIC MATERIALS
    Type: Textile Research Journal (ISSN 0040-5175); 53; July 198
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  • 58
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    Cavitation erosion characteristics of poly(methyl methacrylate) in a rotating disk device (1983)
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    Publication Date: 2011-08-18
    Description: The cavitation erosion behavior including the initiation, dynamics and mechanism of damage process on perspex and epoxy resin specimens tested in a rotating disk device were discussed with respect to exposure time. The inception of erosion always took place at the location nearest to the center of rotation of the disk. Subsequently, as exposure time increased, erosion initiated at other locations as well. Light optical photographs and scanning electron micrographs clearly indicate that most of the material loss appears to occur form the networks of cracks due to their interaction and pits indicate particle debris. The optical degradation (loss of transmittance) on perspex was observed to be more on the rear side than on the front side. Previously announced in STAR as N83-11329
    Keywords: NONMETALLIC MATERIALS
    Type: (ISSN 0043-1648)
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  • 59
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    Comprehensive missile aerodynamics programs for preliminary design (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 12, p. 1851, Accession no. A82-27106
    Keywords: AERODYNAMICS
    Type: (ISSN 0022-4560)
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  • 60
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    Equivalent angle-of-attack method for estimating nonlinear aerodynamics of missile fins (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 19, p. 2971, Accession no. A82-39113
    Keywords: AERODYNAMICS
    Type: (ISSN 0022-4560)
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  • 61
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    Aerodynamics of wraparound fins (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 07, p. 863, Accession no. A83-21011
    Keywords: AERODYNAMICS
    Type: (ISSN 0022-4560)
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  • 62
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    Numerical calculation of nonlinear aerodynamics of wing-body configurations (1983)
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 07, p. 864, Accession no. A83-21022
    Keywords: AERODYNAMICS
    Type: (ISSN 0001-1452)
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  • 63
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    Microwave and hard X-ray observations of a solar flare with a time resolution better than 100 ms (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Simultaneous microwave and X-ray observations are presented for a solar flare detected on 1980 May 8 starting at 1937 UT. The X-ray observations were made with the Hard X-ray Burst Spectrometer on the Solar Maximum Mission and covered the energy range from 28-490 keV with a time resolution of 10 ms. The microwave observations were made with the 5 and 45 foot antennas at the Itapetinga Radio Obervatory at frequencies of 7 and 22 GHz, with time resolutions of 100 ms and 1 ms respectively. Detailed correlation analysis of the different time profiles of the event show that the major impulsive in the X-ray flux preceded the corresponding microwave peaks at 22 GHz by about 240 ms. For this particular burst the 22 GHz peaks preceded the 7 GHz by about 1.5s. Observed delays of the microwave peaks are too large for a simple electron beam model but they can be reconciled with the speeds of shock waves in a thermal model. Previously announced in STAR as N82-30215
    Keywords: SOLAR PHYSICS
    Type: Solar Physics (ISSN 0038-0938); 84; April 19
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    Benchmark determination of Shuttle Orbiter entry aerodynamic heat-transfer data (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 07, p. 965, Accession no. A82-19777
    Keywords: AERODYNAMICS
    Type: (ISSN 0022-4560)
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    The isotopic composition of solar flare noble gases (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The relative elemental and isotopic abundances of noble gases provide insights into a number of topics related to the solar system. Neon is in many ways the most diagnostic of the noble gases. The diagnostic character is mainly related to the variation in the relative abundance of the two most abundant neon isotopes, Ne-20 and Ne-22. The available evidence suggests that trapped neon found in meteorites and in lunar samples consists of as many as five isotopically distinct components, including neon A, B, C, D, and E. Neon B has been shown to be due to solar wind neon which has been directly implanted into the material found in a meteorite. It appears that neon E is extrasolar in origin. There exist ambiguities regarding the origins of the remaining three components. The present investigation is concerned with a reexamination of the existing data in an effort to eliminate or at least clarify these ambiguities. It is found that neon C is apparently due to directly implanted, low-energy solar flare neon nuclei.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal; vol. 266
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  • 66
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    Computation of high Reynolds number internal/external flows (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: (Previously cited in issue 17, p. 2878, Accession no. A81-39001)
    Keywords: AERODYNAMICS
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    Ultrahigh Molecular Weight Aromatic Siloxane Polymers (1983)
    In:  CASI
    Details
    Publication Date: 2014-09-11
    Description: Silphenylene-siloxane polymers can be prepared by a condensation reaction of a diol 1,4-bis(hydroxydimethylsilyl)benzene and a silane bis(dimethylamino)dimethylsilane. Using a stepwise condensation technique, a polymer (R=CH3) with a molecular weight in excess of 1.0 x 1 million has been produced. The polymer exhibits increased thermal stability, compared to a methyl siloxane polymer without the aromatic phenyl ring in the backbone. The use of bis(dimethylamino)methylvinylsilane should allow for ready crosslinking at the vinyl sites (R=-CH=CH2) introduced into the backbone. However, under the conditions of the reaction system a high molecular weight polymer was not obtained or the polymer underwent a crosslinking process during the synthesis.
    Keywords: NONMETALLIC MATERIALS
    Type: Alabama Univ. Res. Rept.: 1983 NASA(ASEE Summer Faculty Fellowship Program; 13 p
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  • 68
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    Comparison of subsonic/transonic aftbody flow prediction methods (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: (Previously cited in issue 21, p. 3614, Accession no. A81-44900)
    Keywords: AERODYNAMICS
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  • 69
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    The rotational spectrum of g-modes in the sun (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Observations and calculations are presented which strongly suggest that the unique sequence of rotation rates due to g-modes is active in the sun. It is found that all angular harmonics from 1 = 2-11 appear to be resolved, while higher harmonics up to at least 1 = 20 also seem to be active. The extreme narrowness of many of the spectral lines indicates that the g-modes are locked in sets of constant 1 by a local mechanism which excites the modes and possibly regulates the long-term precision of their rotation. These sets act as a system of resonant, or nearly resonant, clocks which impose a degree of periodicity upon solar activity and measure the mean solar interior rotation
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal; vol. 264
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  • 70
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    Linear/nonlinear behavior in unsteady transonic aerodynamics (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: (Previously cited in issue 12, p. 1923, Accession no. A81-29496)
    Keywords: AERODYNAMICS
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  • 71
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    Effects of spanwise blowing and reverse thrust on fighter low-speed aerodynamics (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: (Previously cited in issue 07, p. 963, Accession no. A82-19203)
    Keywords: AERODYNAMICS
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  • 72
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    Observation of chromospheric evaporation during the Solar Maximum Mission (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A study is presented of the upward motions of part of the soft X-ray emitting plasma using data for flares collected in 1980 by the Bent Crystal Spectrometer and the Hard X-ray Burst Spectrometer on the Solar Maximum Mission satellite. Results show that upward motions of the soft X-ray plasma are temporally associated with the build up of the thermal phase of flares and with the period of energy deposition as indicated by the hard X-ray emission. In addition, it is found that the hardness of the hard X-ray spectrum, the evaporation velocity, and the rate of increase of the gradual phase are correlated. It is also possible that the total electron energy deposited in the chromosphere, the peak emission measure of the evaporating plasma, and the peak emission measure of the thermal coronal plasma may also be correlated.
    Keywords: SOLAR PHYSICS
    Type: (ISSN 0038-0938)
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  • 73
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    Conductive flux in the chromosphere derived from line linear polarization observation (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: It is shown that quantitative information on the mechanisms of energy transport which take place in solar flares can be obtained by measurement of impact line polarization. Linear polarization in two chromospheric lines (H-alpha and SI 1437 A) observed in the gradual phase of solar flares was investigated. The polarized electric vector is shown to be directed towards the center of the disk. The relationship between conductive heat flux and linear line polarization is determined using a function which represents the velocity distribution of electrons carrying heat flux. The relationship between linear polarization and heat flux is applied to the observed degree of polarization, which yields the conductive heat flux in the high chromosphere. It is determined that this conductive flux is of the order of magnitude of the total radiation loss in the chromosphere and below, which is also of the order of magnitude of the conductive flux in the transition zone.
    Keywords: SOLAR PHYSICS
    Type: (ISSN 0038-0938)
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  • 74
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    Radio blips and hard X-rays in solar flares (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The properties of short, narrow-band spikes occurring in groups at decimetric wavelengths have been extensively analyzed. The bursts, termed blips in the literature, have been found to appear in the impulsive phase of flares. They are associated with hard X-ray emission in 40 percent of all cases with simultaneous coverage. The correspondence between blips and X-ray spikes is generally not one-to-one, blips being more numerous than X-ray spikes. In some cases, however, close correlations between single events have been found. Blips have been discovered to drift in frequency and to decay in time similarly to type III bursts at lower frequency. They also resemble type III bursts in polarization. An analysis of starting frequencies, however, clearly shows that blips and type III bursts belong to different statistical populations. The narrow bandwidth of blips, the major qualitative difference with respect to type III bursts, suggests that blips are the signature of electron beams which either decay rapidly or have a locally enhanced emission due to the presence of some low-frequency wave. Blips have been shown to be an impulsive phase phenomenon occurring at densities of one to three billion per cu cm in the low corona.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 271; Aug. 1
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    Physical conditions in a quiescent prominence derived from UV spectra obtained with the UVSP instrument on the SMM (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A quiescent prominence observed above the north-west limb on November 20, 1980, is analyzed using data obtained with the UV spectrometer and polarimeter (UVSP) on the Solar Maximum Mission (SMM). The spectral data include the lines 1215 A of H1, 1401 A of OIV, 1402 A of SIIV, 1548 A of CIV, 1640 A of HeI, and 1655 A of CI. From an analysis of these lines and their emission patterns, the physical characteristics of the prominence plasma are deduced, and it is suggested that the prominence consisted of flux tubes at various temperatures. In the hotter parts of the plasma the number density reached values of about 3 x 10 to the 11th/cu cm.
    Keywords: SOLAR PHYSICS
    Type: Solar Physics (ISSN 0038-0938); 84; April 19
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  • 76
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    Vertical gradients of sunspot magnetic fields (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The results of a Solar Maximum Mission (SMM) guest investigation to determine the vertical gradients of sunspot magnetic fields for the first time from coordinated observations of photospheric and transition-region fields are described. Descriptions are given of both the photospheric vector field of a sunspot, derived from observations using the NASA Marshall Space Flight Center vector magnetograph, and of the line-of-sight component in the transition region, obtained from the SMM Ultraviolet Spectrometer and Polarimeter instrument. On the basis of these data, vertical gradients of the line-of-sight magnetic field component are calculated using three methods. It is found that the vertical gradient of Bz is lower than values from previous studies and that the transition-region field occurs at a height of approximately 4000-6000 km above the photosphere.
    Keywords: SOLAR PHYSICS
    Type: Solar Physics (ISSN 0038-0938); 84; April 19
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  • 77
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    Computation of nonequilibrium, supersonic three-dimensional inviscid flow over blunt-nosed bodies (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 15, p. 2120, Accession no. A75-33931
    Keywords: AERODYNAMICS
    Type: (ISSN 0001-1452)
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  • 78
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    Separated trailing-edge flow at a transonic Mach number (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 06, p. 800, Accession no. A82-17899
    Keywords: AERODYNAMICS
    Type: (ISSN 0001-1452)
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  • 79
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    Unsteady transonic small disturbance approximation with strong shock waves (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 06, p. 797, Accession no. A82-17812
    Keywords: AERODYNAMICS
    Type: (ISSN 0001-1452)
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  • 80
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    Dynamics and spectroscopy of asymmetrically heated coronal loops (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Numerical models of steady flows along coronal magnetic flux tubes of varying cross sectional areas are investigated. The flows are induced by altering the spatial symmetry of the heating. In two cases the flux tube geometry is symmetric about the top of the loop, but the spatial dependence of the heating rate is changed from a symmetric deposition which supports a stationary equilibrium to a time-independent asymmetric deposition. In a third case the volumetric heating rate is uniform, but one half of the loop is larger in volume than the other. The resulting velocity structure varies significantly with changes in the flux tube geometry. Calculations of the ionization balance and line emission for a number of ionization stages of oxygen suggest that heating induced flows may be responsible for the redshifts seen in spectral lines formed in the network at transition region temperatures.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal; vol. 267
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  • 81
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    Grid generation in three dimensions by Poisson equations with control of cell size and skewness at boundary surfaces (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: An algorithm for generating computational grids about arbitrary three-dimensional bodies is developed. The elliptic partial differential equation (PDE) approach developed by Steger and Sorenson and used in the NASA computer program GRAPE is extended from two to three dimensions. Forcing functions which are found automatically by the algorithm give the user the ability to control mesh cell size and skewness at boundary surfaces. This algorithm, as is typical of PDE grid generators, gives smooth grid lines and spacing in the interior of the grid. The method is applied to a rectilinear wind-tunnel case and to two body shapes in spherical coordinates.
    Keywords: AERODYNAMICS
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  • 82
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    An orthogonal coordinate grid following the three-dimensional viscous flow over a concave surface (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Swept wings designed for laminar flow control exhibit both centrifugal and crossflow instabilities which produce streamwise vortices that can lead to early transition from laminar to turbulent flow in the presence of Tollmien-Schlichting waves. This paper outlines an iterative algorithm for generation of an orthogonal, curvilinear, coordinate grid following the streamlines of the three-dimensional viscous flow over a swept, concave surface. The governing equations for the metric tensor are derived from the Riemann-Christoffel tensor for an Euclidian geometry. Unit vectors along streamline, normal and binormal directions are determined. The governing equations are not solved directly, but are employed only as compatibility equations. The scale factor for the streamline coordinate is obtained by an iterative integration scheme on a 200 x 100 x 5 grid, while the other two scale factors are determined from definitions. Sample results are obtained which indicate that the compatibility equation error decreases linearly with grid step size. Grids smaller than 200 x 100 x 5 are found to be inadequate to resolve the grid curvature.
    Keywords: AERODYNAMICS
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  • 83
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    Investigation of tangential blowing applied to a subsonic V/STOL inlet (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Previously cited in issue 17, p. 2675, Accession no. A82-35195
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 20; 926-934
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  • 84
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    Microwave signatures from a reconnecting plasma pinch, with application to loop flares (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A calculation is made of microwave signature of a cylindrical plasma pinch undergoing magnetic reconnection, a process which occurs in many astrophysical situations, such as solar flares. Depending on the viewing angle and the average energy of the accelerated electrons, the microwaves from this betatron-like source show various amounts of circular polarization. The degree of polarization is shown to be frequency dependent, and the sense of polarization is sometimes reversed. The power spectrum is predicted to have several interesting properties, which can be compared with high-resolution measurements.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 275; 901-915
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  • 85
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    Applicability of the independence principle to subsonic turbulent flow over a swept rearward-facing step (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Prandtl (1946) has concluded that for yawed laminar incompressible flows the streamwise flow is independent of the spanwise flow. However, Ashkenas and Riddell (1955) have reported that for turbulent flow the 'independence principle' does not apply to yawed flat plates. On the other hand, it was also found that this principle may be applicable to many turbulent flows. As the sweep angle is increased, a sweep angle is reached which defines the interval over which the 'independence principle' is valid. The results obtained in the present investigation indicate the magnitude of the critical angle for subsonic turbulent flow over a swept rearward-facing step.
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 21; 1603
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  • 86
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    Implicit, nonswitching, vector-oriented algorithm for steady transonic flow (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A rapid computation of a sequence of transonic flow solutions has to be performed in many areas of aerodynamic technology. The employment of low-cost vector array processors makes the conduction of such calculations economically feasible. However, for a full utilization of the new hardware, the developed algorithms must take advantage of the special characteristics of the vector array processor. The present investigation has the objective to develop an efficient algorithm for solving transonic flow problems governed by mixed partial differential equations on an array processor.
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 21; 1601-160
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  • 87
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    Time-dependent finite-difference simulation of unsteady interactive flows (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The solution of the time-dependent, Reynolds-averaged, Navier-Stokes equations for unsteady, interacting flows by finite-difference algorithms is discussed. Specific examples include (1) unsteady transonic flow over a thick biconvex airfoil, (2) determination of buffet boundaries for a transonic lifting airfoil, (3) the simulation of aileron buzz and (4) dynamic stall. Algorithms considered include explicit methods, mixed (or hybrid) methods, and fully implicit methods. Consideration of time scales for computational stability, computational accuracy, and physical accuracy and the use of time-dependent adaptive meshing to realize computational efficiency are also discussed.
    Keywords: AERODYNAMICS
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  • 88
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    Symposium on Numerical and Physical Aspects of Aerodynamic Flows, 2nd, California State University, Long Beach, CA, January 17-20, 1983, Proceedings (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The present conference covers topics concerning the measurement and calculation of interactive flows, together with problems posed by subsonic and transonic wings, missiles, and ships. Discussions are presented on the time-dependent finite difference simulation of unsteady interactive flows, Navier-Stokes equation methods, numerical solutions for spatially periodic boundary layers, the application of unsteady laminar tripple deck theory to viscous-inviscid interaction, the coupling of boundary layer and Euler equation solutions, and viscous-inviscid flow interactions. Also discussed are leading and trailing edge flows, three-dimensional wing flows, small disturbance calculations including entropy corrections, an inviscid computational method for tactical missiles, and boundary layer and flow separation characteristics of bodies of revolution at incidence.
    Keywords: AERODYNAMICS
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  • 89
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    Investigation of supersonic separated flow in a compression corner by laser Doppler anemometry (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A single-component, computer-operated, three dimensional traversing laser Doppler velocimetry system was designed and constructed for a supersonic wind tunnel. The model was a 10 deg compression corner, providing an example of laminar boundary layer separation. Static pressure data and color schlieren photographs were taken. The Mach number was 2.42 and the Reynolds number was 213,000. The flow was seeded with submicron sized oil droplets. The trend of decreasing upstream influence with increasing Reynolds number was confirmed. Mean velocity profiles provided experimental evidence of reversed flow. Points of separation and reattachment were consistent with those determined by schlieren and pressure scans. The flow was of the laminar type until downstream of reattachment. Individual mean velocity and turbulence profiles, as well as velocity histograms are presented.
    Keywords: AERODYNAMICS
    Type: Experiments in Fluids (ISSN 0723-4864); 1; 4, 19
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  • 90
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    Fire- and heat-resistant laminating resins based on maleimido-substituted aromatic cyclotriphosphazenes (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: A novel class of flame- and heat-resistant polymers has been synthesized by the thermal polymerization of maleimido-substituted aromatic cyclotriphosphazenes. The polymer obtained from tris-(aminophenoxy)tris(maleimidophenoxy)cyclotriphosphazene has good thermal stability and is noteworthy for its high char yield, viz., 82 percent at 800 C in nitrogen and 81 percent at 700 C in air. Graphite-fabric laminates prepared with this polymer did not burn in pure oxygen, even at 300 C, and were tested for mechanical properties. Hexakis(4-maleimidophenoxy)cyclotriphosphazene and some fluorine-containing monomers have also been synthesized. The structures of these cyclic phosphazene precursors and polymers were characterized by FT IR spectrophotometry, H-1 NMR, F-19 NMR, and P-31 solid-state magic angle spinning NMR spectroscopy, and mass spectrometry. The curing behavior of the polymer precursors and the thermal stabilities of the polymers were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA).
    Keywords: NONMETALLIC MATERIALS
    Type: Macromolecules (ISSN 0024-9297); 16; 8, 19
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  • 91
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    Effects of core perturbations on the structure of the sun (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The effects of perturbing the inner part of the solar core where the hydrogen abundance has been partially depleted by nuclear burning are investigated. Small regions are mixed within the core and the evolution of the resulting luminosity and radius perturbations is followed. The sensitivity of the solar luminosity and radius to mixing events of different sizes and at different locations in the core is determined and several relationships between the luminosity and radius perturbations are examined to see if the value of one of these perturbations can be inferred from a measurement of the other. It is found that any core perturbation which alters the hydrostatic structures will immediately affect the solar luminosity and radius. The behavior of these perturbations depends on the location of the mixing event within the core. Mixing events cannot produce the decrease in the solar radius without leading to a homogeneous evolution of the solar core and/or to a prohibitively large change in the solar luminosity.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 273; 795-804
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  • 92
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    Si III line ratios in the sun (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: New atomic data for Si III have been used to predict level populations and emission-line intensity ratios for electron densities and temperatures appropriate to the solar transition region. The electron impact collision rates used here are substantially larger than those previously published owing to delineation of the complex resonance structures in the low-energy collision strengths. This together with small changes in the spontaneous radiative rates produces significant changes in the calculated intensity ratios. Generally good agreement is found with observations obtained using the Naval Research Laboratory slit spectrograph aboard Skylab, electron densities from three Si III ratios and from other methods normally agreeing to 0.2 dex or better for a wide variety of solar features. For a fourth ratio, incorporating lines with a wide wavelength separation, the agreement is less satisfactory, possibly owing to uncertainties in the observational data.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 274; 420-428
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  • 93
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    Thermal response of advanced high temperature ceramic-composite insulation to a convectively heated environment (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The Space Shuttle uses currently fibrous high temperature, reusable surface insulation (HRSI) as a Thermal Protection System (TPS) at 1260 C for normal-design mission operation. Higher density material of a similar type extended the maximum temperature to 1480 C. However, a surface temperature capability exceeding 1540 C is desired for future space vehicles, such as the Orbital Transfer Vehicle (OTV). A TPS providing such a capability would permit future entry vehicles to enter the atmosphere at a much higher velocity than the Space Shuttle. The present investigation is concerned with arc-jet test data obtained from a family of fibrous refractory-composite insulation (FRCI) materials developed to meet the future TPS requirements. FRCI materials containing between 20 and 80 percent aluminoborosilicate fibers with the balance composed of silica fibers were studied.
    Keywords: NONMETALLIC MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 533-550
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  • 94
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    Fire resistant films for aircraft applications (1983)
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    Publication Date: 2011-08-18
    Description: Alternative sandwich panel decorative films were investigated as replacements for the polyvinyl fluoride currently used in aircraft interiors. Candidate films were studied for flammability, smoke emission, toxic gas emission, flame spread, and suitability as a printing surface for the decorative acrylic ink system. Several of the candidate films tested were flame modified polyvinyl fluoride, polyvinylidene fluoride, polyimide, polyamide, polysulfone, polyphenylsulfone, polyethersulfone, polybenzimidazole, polycarbonate, polyparabanic acid, polyphosphazene, polyetheretherketon, and polyester. The films were evaluated as pure films only, films silk-screened with an acrylic ink, and films adhered to a phenolic fiberglass substrate. Films which exhibited the highest fire resistant properties included PEEK polyetheretherketon, Aramid polyamide, and ISO-BPE polyester. Previously announced in STAR as N83-22320
    Keywords: NONMETALLIC MATERIALS
    Type: Journal of Fire Sciences (ISSN 0734-9041); 1; 200-220
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  • 95
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    Lines of Fe XII sensitive to coronal electron density (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Lines of Fe XII sensitive to coronal electron density are discussed. The lines appear in solar spectra obtained by the Naval Research Laboratory (NRL) slit spectograph flown on Skylab. These lines are due to transitions between levels of the 3s 2 3p 3 configuration and fall at the wavelengths 1242.03 A, 1349.38 A, 2169.03 A, 2405.71 A, and 2565.99 A. It is shown that the line at 2169.03 A is severely blended by a line of Ni II at heights less than 12 arcsec outside the solar limb. Above 12 arcsec the lines at 2169.03 and 2405.71 A are apparently unblended and can be used to derive electron densities. An average coronal electron pressure of 6 x 10 to the 14th/cu cm K is obtained. However, the emitting path lengths of the Fe XII lines, deduced using the electron densities and absolute intensities, are unrealistically large. The reason for this difficulty is unclear.
    Keywords: SOLAR PHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 273; 822-828
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  • 96
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    The efficient solution of transonic wing flow fields (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: An evaluation of the transonic-wing-analysis computer code TWING is presented. TWING utilizes a fully implicit, approximate-factorization iteration scheme to solve the full-potential equation in conservative form. A numerical elliptic-solver grid-generation scheme is used to generate the required finite-difference mesh. Several wing configurations have been analyzed, and comparisons of computed results have been made with available experimental data. Results indicate that the code is robust, accurate (when significant viscous effects are not present), and efficient. TWING generally produces solutions an order of magnitude faster than other conservative, full-potential codes using successive-line overrelaxation. The present method is applicable to a wide range of isolated wing configurations, including high-aspect-ratio transport wings and low-aspect-ratio, high-sweep, fighter configurations.
    Keywords: AERODYNAMICS
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  • 97
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    Transonic small disturbance calculations including entropy corrections (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Murman's fully conservative mixed type finite-difference operators are first modified. A special sonic point operator with an iterative damping term is introduced which helps the convergence and does not affect the spatial conservative differences. Reliable calculations with second order supersonic schemes are obtained using two sonic operators, the regular sonic point operator followed by a first order supersonic scheme. Also, shock point operator is shown to be equivalent to fitting a locally normal shock terminating the supersonic region. The potential calculations are then modified to account for the non-isentropic jump conditions using a simple shock fitting procedure based on Prandtl relation. The entropy increase across the shock is calculated in terms of the Mach number upstream of the shock and the effect of the generated vorticity is estimated via Crocco relation. Different examples are calculated and extensions to the full potential equation are discussed.
    Keywords: AERODYNAMICS
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  • 98
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    Numerical simulation of turbulent trailing edge flows (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Numerical simulations of the time-dependent, Reynolds-averaged, Navier-Stokes equations, employing a two-equation turbulence model, are presented and compared with measurements from a series of trailing edge experiments at transonic Mach numbers. The test flows include an asymmetric flow with no separation, an asymmetric flow with a small region of separation and a symmetric flow with a large shock-wave induced separated zone. Comparisons are made for mean surface quantities as well as for mean and fluctuating flow-field quantities. For the trailing-edge flows with little or no separation, the solutions correctly predict all the major features of the flow field. Treatment of the viscous-inviscid interaction was found to be important for predicting these test cases. Two-equation eddy-viscosity turbulence models were found to be adequate for these flows. However, for the shock-wave induced separation case, these turbulence models were inadequate to predict this flow field. Modifications of the turbulence model to correct these deficiencies are discussed.
    Keywords: AERODYNAMICS
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  • 99
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    A basic design fault in ceramic flat packs (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: Recent moisture resistance tests of various multilayer top brazed ceramic flat packs and leaded and unleaded chip carriers has revealed a serious design defect. These packages, which utilize a tungsten interconnect system, in the presence of high humidity, suffer a galvanic corrosion which anodically consumes the tungsten. This process can continue until the package suffers an open circuit. The test results indicate that the lead plating system does not adequately seal off the interface area where the tungsten stripe egresses from the inside of the package. Leaded and leadless chip carrier packages were also subjected to the moisture resistance test. The familiar red and green corrosion products were visible after the test was completed. Careful sectioning of the chip carriers has revealed that the tungsten interconnect stripe instead of exiting under the castellations, exits at the top of the castellation and is thus vulnerable to the attack of moisture. These basic design faults severely impact the reliability of these packages.
    Keywords: NONMETALLIC MATERIALS
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  • 100
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    Resin characterization in cured graphite fiber reinforced composites using diffuse reflectance-FTIR (1983)
    In:  Other Sources
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    Publication Date: 2011-08-18
    Description: The feasibility of using diffuse reflectance in combination with Fourier transform infrared spectroscopy to obtain information on cured graphite fiber reinforced polymeric matrix resin composites was investigated. Several graphite/epoxy, polysulfone, and polyimide composites exposed to thermal or radiation environments were examined. An experimental polyimide-sulfone adhesive tape was also studied during processing. In each case, significant changes in resin molecular structure was observed due to environmental exposure. These changes in molecular structure were correlated with previously observed changes in material properties providing new insights into material behavior.
    Keywords: NONMETALLIC MATERIALS
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