1,118 research outputs found

    Topological Density and Instantons on a Lattice

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    We present an update on the study of topological structure of QCD. Issues addressed include a comparison between the plaquette and the geometric methods of calculating the topological density. We show that the improved gauge action based on sqrt(3) blocking transformation suppresses the formation of topologically charged dislocations with low action. Using a cooling method we identify the instantons' location, estimate their size and density, and calculate the renormalization constant Z_Q for the plaquette method.Comment: 3 Pages, submitted to Proceedings of XII International Symposium on Lattice Field Theory (Lattice 94, Bielefeld). uuencoded tar file includes figures as TeXDraw (.tex) file

    Crew interface definition study, phase 1

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    The timeline analysis of the Shuttle orbiter missions which was conducted in the Phase I Crew Interface Definition Study and the requirements for the man-in-the-loop simulation study are presented. Mission definitions and objectives are presented as they relate to various Shuttle Orbiter missions. The requirements for crew participation and the information required by the crew are discussed, and finally the rationale behind the display concept and calling procedures is given. The simulation objectives, the simulation mechanization, including a detailed presentation of the display and control concept, the simulator test plan and the results are discussed

    Melting curve of 4^4He: no sign of the supersolid transition down to 10 mK

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    We have measured the melting curve of 4^4He in the temperature range from 10 to 400 mK with the accuracy of about 0.5 μ\mubar. Crystals of different quality show the expected T4T^4-dependence in the range from 80 to 400 mK without any sign of the supersolid transition, and the coefficient is in excellent agreement with available data on the sound velocity in liquid 4^4He and on the Debye temperature of solid 4^4He. Below 80 mK we have observed a small deviation from T4T^4-dependence which however cannot be attributed to the supersolid transition because instead of decrease the entropy of the solid rather remains constant, about 2.5×1062.5\times10^{-6} RRComment: 4 pages, 2 figures, published in Physical Review Letter

    Spin susceptibility of the superfluid 3^{3}He-B in aerogel

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    The temperature dependence of paramagnetic susceptibility of the superfluid ^{3}He-B in aerogel is found. Calculations have been performed for an arbitrary phase shift of s-wave scattering in the framework of BCS weak coupling theory and the simplest model of aerogel as an aggregate of homogeneously distributed ordinary impurities. Both limiting cases of the Born and unitary scattering can be easily obtained from the general result. The existence of gapless superfluidity starting at the critical impurity concentration depending on the value of the scattering phase has been demonstrated. While larger than in the bulk liquid the calculated susceptibility of the B-phase in aerogel proves to be conspicuously smaller than that determined experimentally in the high pressure region.Comment: 10 pages, 4 figures, REVTe

    Power Corrections to Perturbative QCD and OPE in Gluon Green Functions

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    We show that QCD Green functions in Landau Gauge exhibit sizable O(1/μ2)O(1/\mu^2) corrections to the expected perturbative behavior at energies as high as 10 GeV. We argue that these are due to a -condensate which does not vanish in Landau gauge.Comment: 3 pages 1 figure lattice2001 (gaugetheories

    Wetting of Superfluid 4He by Liquid 3He

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    We have investigated optically the spreading of He3 on top of the He4-rich solution in phase-separated helium-mixture films, 20-50 μm thick. In equilibrium, the He3 layer wets the He4-rich phase completely, but nearly circular or stripelike pools of He3-rich phase are stabilized instead when He4 atoms are condensed to the liquid sample at the rate 10 exp 15-5 × 10 exp 15 atoms/cm2s. For the contact angle we obtain about 10 mrad, which suggests a fractional change of the He3 surface tension by a factor of 10 exp −5 from the equilibrium value.Peer reviewe

    Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science

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    The Wide-field Infrared Survey Explorer (WISE) has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the Infrared Astronomical Satellite and the Cosmic Background Explorer. NASA's Planetary Science Division has funded an enhancement to the WISE data processing system called "NEOWISE" that allows detection and archiving of moving objects found in the WISE data. NEOWISE has mined the WISE images for a wide array of small bodies in our solar system, including near-Earth objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in 2011 February, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and ~120 comets. The NEOWISE data set will enable a panoply of new scientific investigations

    Efeito da altura do resíduo sobre a produção e a estrutura de sorgo forrageiro.

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    O cultivo de sorgo forrageiro (Sorghum bicolor (L.) Moench.) tem crescido na região Noroeste do Rio Grande do Sul nos últimos anos. Os produtores rurais estão sendo orientados a manejar o sorgo forrageiro em pastejo rotacionado, respeitando uma altura de entrada dos animais acima de 70 cm e altura de saída (resíduo) em torno de apenas 5 cm.bitstream/item/63868/1/BP31.pd
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