23,446 research outputs found

    Investigation of implantable multichannel biotelemetry Semiannual report, Mar. - Aug. 1968

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    Multichannel, physiologically implantable telemetering system for biological measurement

    Dynamic interaction between structure and liquid propellants in a space shuttle vehicle model, part 1 Final report

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    Dynamic interaction between structure and liquid propellants in space shuttle vehicle model

    Investigation if implantable multichannel biotelemetry systems Semiannual report, Sep. 1967 - Feb. 1968

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    Operation and maintenance of multichannel, physiologically implantable telemetering systems for biological measurement

    Coupling between structure and liquids in a parallel stage space shuttle design

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    A study was conducted to determine the influence of liquid propellants on the dynamic loads for space shuttle vehicles. A parallel-stage configuration model was designed and tested to determine the influence of liquid propellants on coupled natural modes. A forty degree-of-freedom analytical model was also developed for predicting these modes. Currently available analytical models were used to represent the liquid contributions, even though coupled longitudinal and lateral motions are present in such a complex structure. Agreement between the results was found in the lower few modes

    Applicability valuation for evaluation of surface deflection in automotive outer panels

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    Upon unloading in a forming process there is elastic recovery, which is the release of the elastic strains and the redistribution of the residual stresses through the thickness direction, thus producing surface deflection. It causes changes in shape and dimensions that can create major problem in the external appearance of outer panels. Thus surface deflection prediction is an important issue in sheet metal forming industry. Many factors could affect surface deflection in the process, such as material variations in mechanical properties, sheet thickness, tool geometry, processing parameters and lubricant condition. The shape and dimension problem in press forming is defined as a trouble mainly caused by the elastic recovery of materials during the forming. The use of high strength steel sheets in the manufacturing of automobile outer panels has increased in the automotive industry over the years because of its lightweight and fuel-efficient improvement. But one of the major concerns of stamping is surface deflection in the formed outer panels. Hence, to be cost effective, accurate prediction must be made of its formability. The automotive industry places rigi

    Analytical and numerical studies of central galactic outflows powered by tidal disruption events -- a model for the Fermi bubbles?

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    Capture and tidal disruption of stars by the supermassive black hole in the Galactic center (GC) should occur regularly. The energy released and dissipated by this processes will affect both the ambient environment of the GC and the Galactic halo. A single star of super-Eddington eruption generates a subsonic out ow with an energy release of more than 105210^{52} erg, which still is not high enough to push shock heated gas into the halo. Only routine tidal disruption of stars near the GC can provide enough cumulative energy to form and maintain large scale structures like the Fermi Bubbles. The average rate of disruption events is expected to be 10410^{-4} ~ 10510^{-5} yr1^{-1}, providing the average power of energy release from the GC into the halo of dW/dt ~ 3*1041^{41} erg/s, which is needed to support the Fermi Bubbles. The GC black hole is surrounded by molecular clouds in the disk, but their overall mass and filling factor is too low to stall the shocks from tidal disruption events significantly. The de facto continuous energy injection on timescales of Myr will lead to the propagation of strong shocks in a density stratified Galactic halo and thus create elongated bubble-like features, which are symmetric to the Galactic midplane.Comment: 11 pages, 5 figures. The title and abstract have been changed. Accepted by Astrophysical Journa

    Quantum Gravitational Effects and Grand Unification

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    In grand unified theories with large numbers of fields, renormalization effects significantly modify the scale at which quantum gravity becomes strong. This in turn can modify the boundary conditions for coupling constant unification, if higher dimensional operators induced by gravity are taken into consideration. We show that the generic size of, and the uncertainty in, these effects from gravity can be larger than the two-loop corrections typically considered in renormalization group analyses of unification. In some cases, gravitational effects of modest size can render unification impossible.Comment: 3 pages, to appear in the proceedings of 16th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY08), Seoul, Korea, June 16-21 200

    Advanced electronic technology and the design and development of an integral circuit, multi-channel telemetry system for bio-medical applications Final report, Mar. 1966 - Feb. 1969

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    Application of electronic technology to design and development of integrated circuit, telemetry system for biomedicin

    Flavor ordering of elliptic flows at high transverse momentum

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    Based on the quark coalescence model for the parton-to-hadron phase transition in ultra-relativistic heavy ion collisions, we relate the elliptic flow (v2v_2) of high \pt hadrons to that of high \pt quarks. For high \pt hadrons produced from an isospin symmetric and quark-antiquark symmetric partonic matter, magnitudes of their elliptic flows follow a flavor ordering as (v2,π=v2,N)>(v2,Λ=v2,Σ)>v2,K>v2,Ξ>(v2,ϕ=v2,Ω)(v_{2,\pi}=v_{2,N}) > (v_{2,\Lambda}=v_{2,\Sigma}) > v_{2,K} > v_{2,\Xi} > (v_{2,\phi}=v_{2,\Omega}) if strange quarks have a smaller elliptic flow than light quarks. The elliptic flows of high \pt hadrons further follow a simple quark counting rule if strange quarks and light quarks have same high \pt spectrum and coalescence probability.Comment: 4 pages, 1 figure, revte
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