20,291 research outputs found

    Study of radiation effects in Li-doped silicon solar cells Quarterly report

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    Irradiation and annealing of lithium doped silicon solar cell

    Staticity Theorem for Higher Dimensional Generalized Einstein-Maxwell System

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    We derive formulas for variations of mass, angular momentum and canonical energy in Einstein (n-2)-gauge form field theory by means of the ADM formalism. Considering the initial data for the manifold with an interior boundary which has the topology of (n-2)-sphere we obtained the generalized first law of black hole thermodynamics. Supposing that a black hole evevt horizon comprisesw a bifurcation Killing horizon with a bifurcate surface we find that the solution is static in the exterior world, when the Killing timelike vector field is normal to the horizon and has vanishing electric or magnetic fields on static slices.Comment: 10 pages, REVTEX, to published in Phys.Rev. D1

    The generic character table of a Sylow pp-subgroup of a finite Chevalley group of type D4D_4

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    Let UU be a Sylow pp-subgroup of the finite Chevalley group of type D4D_4 over the field of qq elements, where qq is a power of a prime pp. We describe a construction of the generic character table of UU

    Renormalisation of gravitational self interaction for wiggly strings

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    It is shown that for any elastic string model with energy density UU and tension TT, the divergent contribution from gravitational self interaction can be allowed for by an action renormalisation proportional to (U−T)2(U-T)^2. This formula is applied to the important special case of a bare model of the transonic type (characterised by a constant value of the product UTUT) that represents the macroscopically averaged effect of shortwavelength wiggles on an underlying microscopic model of the Nambu-Goto type (characterised by U=TU=T).Comment: 11 pages, Latex; original 8 page version extended to include estimates of relevant orders of magnitude. To be published in Physical Review,

    Development and initial operating characteristics of the 20 megawatt linear plasma accelerator facility

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    A 20-megawatt linear plasma accelerator facility, a steady flow, Faraday-type plasma accelerator facility for high velocity aerodynamic testing, was constructed, developed, and brought to an operational status. The accelerator has a 63.5-mm-square and 0.5-meter-long channel and utilizes nitrogen-seeded with 2 % mole fraction of cesium vapor. Modification of the original accelerator design characteristics and the improvements necessary to make the arc heater a suitable plasma source are described. The measured accelerator electrode current distribution and the electrode-wall potential distributions are given. The computed and the measured values are in good agreement. Measured pitot pressure indicates that an accelerator exit velocity of 9.2 km/sec, is obtained with 30 of the 36 electrode pairs powered and corresponds to a velocity increase to about 2 1/4 times the computed entrance velocity. The computed stagnation enthalpy at the accelerator exit is 92 MJ/kg, and the mass density corresponds to an altitude of about 58 km. The 92 MJ/kg stagnation enthalpy corresponds to a kinetic energy content at low temperature equivalent to a velocity of 13.6 km/sec

    Spinning BTZ Black Hole versus Kerr Black Hole : A Closer Look

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    By applying Newman's algorithm, the AdS_3 rotating black hole solution is ``derived'' from the nonrotating black hole solution of Banados, Teitelboim, and Zanelli (BTZ). The rotating BTZ solution derived in this fashion is given in ``Boyer-Lindquist-type'' coordinates whereas the form of the solution originally given by BTZ is given in a kind of an ``unfamiliar'' coordinates which are related to each other by a transformation of time coordinate alone. The relative physical meaning between these two time coordinates is carefully studied. Since the Kerr-type and Boyer-Lindquist-type coordinates for rotating BTZ solution are newly found via Newman's algorithm, next, the transformation to Kerr-Schild-type coordinates is looked for. Indeed, such transformation is found to exist. And in this Kerr-Schild-type coordinates, truely maximal extension of its global structure by analytically continuing to ``antigravity universe'' region is carried out.Comment: 17 pages, 1 figure, Revtex, Accepted for publication in Phys. Rev.

    NASA rotor system research aircraft flight-test data report: Helicopter and compound configuration

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    The flight test activities of the Rotor System Research Aircraft (RSRA), NASA 740, from June 30, 1981 to August 5, 1982 are reported. Tests were conducted in both the helicopter and compound configurations. Compound tests reconfirmed the Sikorsky flight envelope except that main rotor blade bending loads reached endurance at a speed about 10 knots lower than previously. Wing incidence changes were made from 0 to 10 deg

    Research on a one-inch-square linear d-c plasma accelerator

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    One-inch-square linear d-c plasma accelerator using cesium seeded nitroge
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