6,825 research outputs found

    Microscopic observation of superconducting fluctuations in Îș\kappa-(BEDT-TTF)2_{2}Cu[N(CN)2_{2}]Br by 13^{13}C NMR spectroscopy

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    We performed 13^{13}C-NMR experiment and measured spin-lattice relaxation rate divided by temperature 1/T1T1/T_{1}T near the superconducting (SC) transition temperature TcT_{c} in Îș\kappa-(BEDT-TTF)2_{2}Cu[N(CN)2_{2}]Br (Îș\kappa-Br salt), and Îș\kappa-(BEDT-TTF)2_{2}Cu(NCS)2_{2} (Îș\kappa-NCS salt). We observed the reduction of 1/T1T1/T_{1}T starting at the temperature higher than TcT_c in Îș\kappa-Br salt. Microscopic observation of quasi-particle density of states in the fluctuating SC state revealed the effects of short-range Cooper pairs induced in the normal state to the quasi-particle density of states. We also performed systematic measurements in the fields both parallel and perpendicular to the conduction plane in Îș\kappa-Br and Îș\kappa-NCS salts, and confirmed that the reduction of 1/T1T1/T_{1}T above TcT_{c} is observed only in Îș\kappa-Br salt regardless of the external field orientation.Comment: Accepted for publication in PR

    The bosonic string and superstring models in 26+2 and 10+2 dimensional space--time, and the generalized Chern-Simons action

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    We have covariantized the Lagrangians of the U(1)_V * U(1)_A models, which have U(1)_V * U(1)_A gauge symmetry in two dimensions, and studied their symmetric structures. The special property of the U(1)_V * U(1)_A models is the fact that all these models have an extra time coordinate in the target space-time. The U(1)_V * U(1)_A models coupled to two-dimensional gravity are string models in 26+2 dimensional target space-time for bosonic string and in 10+2 dimensional target space-time for superstring. Both string models have two time coordinates. In order to construct the covariant Lagrangians of the U(1)_V * U(1)_A models the generalized Chern-Simons term plays an important role. The supersymmetric generalized Chern-Simons action is also proposed. The Green-Schwarz type of U(1)_V * U(1)_A superstring model has another fermionic local symmetry as well as \kappa-symmetry. The supersymmetry of target space-time is different from the standard one.Comment: 27 pages, no figure

    EFFECTS OF DRYING AND ENSILING METHODS ON CYANIDES CONTENTS AND CHEMICAL COMPONENTS OF CASSAVA ROOTS AND STEMS

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    The objectives of this experiment was to compare the drying and ensiling methods to reduce cyanides contents in cassava, as well as related nutrient components. This experiment used roots and stems of cas-sava, fermented juice of epiphytic lactic acid bacteria (FJLB) and molasses. A completely randomized design was used in this experiment for 8 treatments. The treatments were 30 o C incubator, 50 o C incubator, 70 o C oven drying, freeze drying, 2 d incubator 30 o C ensiling, 2 d incubator 50 o C ensiling, 2 w incubator 30 o C ensiling and 2 w incubator 50 o C ensiling. The contents of HCN, acetone cyanohydrin, linamarin, proximate components and in vitro dry matter digestibility were determined in each treatment. The result of this experi-ment showed that the contents of HCN and linamarin in ensiled cassava roots were lower (p<0.01) than in dried cassava roots. There were no significantly different on residual HCN among treatments in cassava stems. The content of linamarin was higher in freeze drying than that in heat drying methods (p<0.05). There was an opposite pattern of acetone cyanohydrins and linamarin content of roots and stems. The content of dry matter (DM) in 30 o C ensiling was lower than in 50 o C ensiling (p<0.05). The content of ash increased in cassava roots silage (p<0.01), meanwhile the decreasing of ether extract content was occured in cassava stem silage (p<0.01). Ensiling method was more effective to reduce cyanide than the drying method, and cassava silage showed a proper qualification as feed. Keywords: Drying, Ensiling, Cyanides, Cassav

    Recursive sampling simulations of 3D gravity coupled to scalar fermions

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    We study numerically the phase structure of a model of 3D gravity interacting with scalar fermions. We measure the 3D counterpart of the "string" susceptibility exponent as a function of the inverse Newton coupling α\alpha. We show that there are two phases separated by a critical point around αc≃2\alpha_c \simeq 2. The numerical results support the hypothesis that the phase structures of 3D and 2D simplicial gravity are qualitatively similar, the inverse Newton coupling in 3D playing the role of the central charge of matter in 2D.Comment: Latex with 6 figure files, 17 page

    Generalized Gauge Theories and Weinberg-Salam Model with Dirac-K\"ahler Fermions

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    We extend previously proposed generalized gauge theory formulation of Chern-Simons type and topological Yang-Mills type actions into Yang-Mills type actions. We formulate gauge fields and Dirac-K\"ahler matter fermions by all degrees of differential forms. The simplest version of the model which includes only zero and one form gauge fields accommodated with the graded Lie algebra of SU(2∣1)SU(2|1) supergroup leads Weinberg-Salam model. Thus the Weinberg-Salam model formulated by noncommutative geometry is a particular example of the present formulation.Comment: 33 pages, LaTe

    Structure of air shower disc near the core

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    The longitudinal structure of the air shower disk is studied by measuring the arrival time distributions of air shower particles for showers with electron size in the range 3.2 x 10 to the 5.5. power to 3.2 x 10 to the 7.5 power in the Akeno air-shower array (930 gcm squared atmospheric depth). The average FWHM as a parameter of thickness of air shower disk increases with core distances at less than 50m. AT the present stage, dependence on electron size, zenith angle and air shower age is not apparent. The average thickness of the air shower disk within a core distance of 50m could be determined by an electromagnetic cascade starting from the lower altitude

    Search for long-lived massive particles in extensive air showers

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    Air showers containing delayed sub-showers which may be produced by a long-lived massive particle have been investigated by using twelve detectors. Ten events have been selected out as the candidates. However, a definite conclusion cannot be reached at the present time

    Transfer Matrix Formalism for Two-Dimensional Quantum Gravity and Fractal Structures of Space-time

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    We develop a transfer matrix formalism for two-dimensional pure gravity. By taking the continuum limit, we obtain a "Hamiltonian formalism'' in which the geodesic distance plays the role of time. Applying this formalism, we obtain a universal function which describes the fractal structures of two dimensional quantum gravity in the continuum limit.Comment: 13 pages, 5 figures, phyzz
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