3,597 research outputs found

    Notes on the Super Nambu Bracket

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    We define a super Nambu-Poisson algebra over a super manifold. A super Nambu bracket does not satisfy the usual skew-symmetric property, and we propose another skew-symmetric property. We show that the divergence of super Nambu-Hamiltonian vector fields leads to a generalization of the Batalin-Vilkovisky algebra.Comment: 9 pages, no figures, AMS-LaTeX, ptptex.cls, some errors corrected, version to appear in PT

    Magentic-Field Induced Quantum Phase Transition and Critical Behavior in a Gapped Spin System TlCuCl3_3

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    Magnetization measurements were performed on TlCuCl3_3 with gapped ground state. The critical density and the magnetic phase diagram were obtained. The interacting constant was obtained as U/kB=313U/k_{\rm B} = 313 K. The experimental phase boundary for T<5T < 5 K agrees perfectly with the magnon BEC theory based on the Hartree-Fock approximation with realistic dispersion relations and U/kB=320U/k_{\rm B} = 320 K. The exponent Ï•\phi obtained with all the data points for T<5T < 5 K is Ï•=1.99\phi = 1.99, which is somewhat larger than theoretical exponent Ï•BEC=3/2\phi_{\rm BEC} =3/2. However, it was found that the exponent converges at Ï•BEC=3/2\phi_{\rm BEC} =3/2 with decreasing fitting window.Comment: 2 pages, 2 figures, Submitted to Proceedings of International Conference on Magnetism (ICM2006

    Investigation of the components of the NAL high Reynolds number two-dimensional wind tunnel. Part 4: Design, construction and performance of the exhaust silencer

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    Presented is a description of the design construction and performance of the exhaust silencer for the NAL high Reynolds number two-dimensional transonic blow down wind tunnel, which was completed in October 1979. The silencer is a two-storied construction made of reinforced concrete, 40 m. long, 10 m. wide and 19 m. high and entirely enclosed by thick concrete walls. The upstream part of the first story, particularly, is covered with double walls, the thickness of the two walls being 0.3 m. (inner wall) and 0.2 m. (outer wall), respectively. A noise reduction system using three kinds of parallel baffles and two kinds of lined bends is adopted for the wind tunnel exhaust noise

    Three Phases in the 3D Abelian Higgs Model with Nonlocal Gauge Interactions

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    We study the phase structure of the 3D nonlocal compact U(1) lattice gauge theory coupled with a Higgs field by means of Monte-Carlo simulations. The nonlocal interactions among gauge variables are along the temporal direction and mimic the effect of local coupling to massless particles. We found that in contrast to the 3D local abelian Higgs model which has only one phase, the present model exhibits the confinement, Higgs, and Coulomb phases separated by three second-order transition lines emanating from a triple point. This result is quite important for studies on electron fractionalization phenomena in strongly-correlated electron systems. Implications to them are discussed

    A new method of evaluating the side wall interference effect on airfoil angle of attack by suction from the side walls

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    A quantitative evaluation method of the suction effect from a suction plate on side walls is explained. It is found from wind tunnel tests that the wall interference is basically described by the summation form of wall interferences in the case of two dimensional flow and the interference of side walls

    Comparative evaluation of catalyst materials using a binary choice model

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    Advances in algorithms and hardware have enabled computers to design new materials atom-by-atom. However, in order for these computer-generated materials to truly address problems of societal importance, such as clean energy generation, it is not enough for them to have superior physical properties. It is also important for them to be adopted by as many users as possible. In this paper, we present a simple binary choice model for comparing catalyst materials on the basis of consumer preferences. This model considers a population of utility maximisers who select one of two materials by comparing catalytic turnover rates with sales prices. Through a mixture of numerical simulation and analytic theorems, we characterise the predictions of the model in a variety of regimes of consumer behavior. We also show how the model can be used as a guide for crafting policies for lowering catalyst prices in order to improve their market shares. This work represents a first step towards understanding how material properties should be balanced against production costs and consumer demand when designing new materials, an intellectual advance which may facilitate the spread of green materials in society.Comment: 23 pages, 6 figures, 1 table. Re-write and expansion of a previous versio
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