9,463 research outputs found

    Full-Scale Direct Numerical Simulation of Two- and Three-Dimensional Instabilities and Rivulet Formulation in Heated Falling Films

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    A thin film draining on an inclined plate has been studied numerically using finite element method. Three-dimensional governing equations of continuity, momentum and energy with a moving boundary are integrated in an arbitrary Lagrangian Eulerian frame of reference. Kinematic equation is solved to precisely update interface location. Rivulet formation based on instability mechanism has been simulated using full-scale computation. Comparisons with long-wave theory are made to validate the numerical scheme. Detailed analysis of two- and three-dimensional nonlinear wave formation and spontaneous rupture forming rivulets under the influence of combined thermocapillary and surface-wave instabilities is performed

    Simulations of black hole air showers in cosmic ray detectors

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    We present a comprehensive study of TeV black hole events in Earth's atmosphere originated by cosmic rays of very high energy. An advanced fortran Monte Carlo code is developed and used to simulate black hole extensive air showers from ultrahigh-energy neutrino-nucleon interactions. We investigate the characteristics of these events, compare the black hole air showers to standard model air showers, and test different theoretical and phenomenological models of black hole formation and evolution. The main features of black hole air showers are found to be independent of the model considered. No significant differences between models are likely to be observed at fluorescence telescopes and/or ground arrays. We also discuss the tau ``double bang'' signature in black hole air showers. We find that the energy deposited in the second bang is too small to produce a detectable peak. Our results show that the theory of TeV-scale black holes in ultrahigh-energy cosmic rays leads to robust predictions, but the fine prints of new physics are hardly to be investigated through atmospheric black hole events in the near future.Comment: 18 pages, 9 figure

    Generation of two-photon EPR and Wstates

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    In this paper we present a scheme for generation of two-photon EPR and W states in the cavity QED context. The scheme requires only one three-level Rydberg atom and two or three cavities. The atom is sent to interact with cavities previously prepared in vacuum states, via two-photon process. An appropriate choice of the interaction times one obtains the mentioned state with maximized fidelities. These specific times and the values of success probability and fidelity are discussed.Comment: 4 pages, 5 figure

    Smart Suction Muffler Design for A Reciprocating Compressor

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    A New Era in High-energy Physics

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    In TeV-scale gravity, scattering of particles with center-of-mass energy of the order of a few TeV can lead to the creation of nonperturbative, extended, higher-dimensional gravitational objects: Branes. Neutral or charged, spinning or spinless, Einsteinian or supersymmetric, low-energy branes could dramatically change our picture of high-energy physics. Will we create branes in future particle colliders, observe them from ultra high energy cosmic rays, and discover them to be dark matter?Comment: 8 pages, 2 figures. Essay submitted on Mar 26, 2002 to the Gravity Research Foundation. Awarded the third prize in the 2002 GRF competitio

    Quantum teleportation via a W state

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    We investigate two schemes of the quantum teleportation with a WW state, which belongs to a different class from a Greenberger-Horne-Zeilinger class. In the first scheme, the WW state is shared by three parties one of whom, called a sender, performs a Bell measurement. It is shown that quantum information of an unknown state is split between two parties and recovered with a certain probability. In the second scheme, a sender takes two particles of the WW state and performs positive operator valued measurements in two ways. For two schemes, we calculate the success probability and the average fidelity. We show that the average fidelity of the second scheme cannot exceed that of the first one.Comment: 7 pages, 1 figur

    Upper critical field divergence induced by mesoscopic phase separation in the organic superconductor (TMTSF)2ReO4

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    Due to the competition of two anion orders, (TMTSF)2ReO4, presents a phase coexistence between semiconducting and metallic (superconducting) regions (filaments or droplets) in a wide range of pressure. In this regime, the superconducting upper critical field for H parallel to both c* and b' axes present a linear part at low fields followed by a divergence above a cross-over field. This cross-over corresponds to the 3D-2D decoupling transition expected in filamentary or granular superconductors. The sharpness of the transition also demonstrates that all filaments are of similar sizes and self organize in a very ordered way. The distance between the filaments and their cross-section are estimated.Comment: 4 pages, 4 figure
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