167 research outputs found
Effect of Curvature on Fillet Formation during Aluminum Brazing(Materials, Metallurgy & Weldability)
A Proposal for Redesigning Aortofemoral Prosthetic Y Graft for Treating Abdominal Aortic Aneurysms
Agent for preventing and ameliorating aging of skin
PROBLEM TO BE SOLVED: To obtain the subject new cosmetic by compounding a phosphorylated polysaccharide having humectant action and collagen-producing performance as an active component. SOLUTION: This cosmetic contains a compound of the formula (Glc is glucose residue; Gal is galactose residue; Rha is rhamnose residue; (m) is 0-3; (n) is 1,000-5,000) as an active component. The component of the formula can be produced by hydrolyzing actinase E of defatted milk, treating the defatted milk with ultrafiltration membrane, sterilizing the filtrate to obtain a culture medium, aseptically pipetting the sterilized medium into a jar fermenter, inoculating a precultured liquid, culturing at 20 deg.C and pH5.5 using NH3 water as a neutralizing agent, subjecting the cultured product to centrifugal separation after culture to recover the supernatant, adding an equal amount of CH3 OH, recovering the produced precipitate, dissolving the precipitate in 0.2N saline water, repeating the precipitation operation with CH3 OH, subjecting the treated precipitate to electrophoresis, recovering the component impregnated into the gel and purifying the recovered fraction by ion-exchange chromatography to obtain purified polysaccharide. It is necessary to compound a cosmetic with >=0.001wt.% of the compound of the formula.</p
H dibaryon in the QCD sum rule
The QCD sum rule is applied to the H dibaryon and is compared to the flavor
non-singlet di-nucleon. We find that the H dibaryon is almost degenerate to the
di-nucleon in the limit and therefore is not deeply bound as
far as th\ e threshold parameter is adjusted not to have a di-nucleon bound
state. After introducing the breaking effects, the H dibaryon is
found to be bound by below the threshold.Comment: 10 pages 4 uuencoded figures containe
Phase Structure of a 3D Nonlocal U(1) Gauge Theory: Deconfinement by Gapless Matter Fields
In this paper, we study a 3D compact U(1) lattice gauge theory with a variety
of nonlocal interactions that simulates the effects of gapless/gapful matter
fields. This theory is quite important to investigate the phase structures of
QED and strongly-correlated electron systems like the 2D quantum spin
models, the fractional quantum Hall effect, the t-J model of high-temperature
superconductivity. We restrict the nonlocal interactions among gauge variables
only to those along the temporal direction and adjust their coupling constants
optimally to simulate the isotropic nonlocal couplings of the original models.
We perform numerical studies of the model to find that, for a certain class of
power-decaying couplings, there appears a second-order phase transition to the
deconfinement phase as the gauge coupling constant is decreased. On the other
hand, for the exponentially-decaying coupling, there are no signals for
second-order phase transition. These results indicate the possibility that
introduction of sufficient number of massless matter fields destabilizes the
permanent confinement in the 3D compact U(1) pure gauge theory due to
instantons.Comment: The version to be published in Nucl.Phys.
Two-Baryon Potentials and H-Dibaryon from 3-flavor Lattice QCD Simulations
Baryon-baryon potentials are obtained from 3-flavor QCD simulations with the
lattice volume L ~ 4 fm, the lattice spacing a ~ 0.12 fm, and the
pseudo-scalar-meson mass M_ps =469 - 1171 MeV. The NN scattering phase shift
and the mass of H-dibaryon in the flavor SU(3) limit are extracted from the
resultant potentials by solving the Schrodinger equation. The NN phase shift in
the SU(3) limit is shown to have qualitatively similar behavior as the
experimental data. A bound H-dibaryon in the SU(3) limit is found to exist in
the flavor-singlet J^P=0^+ channel with the binding energy of about 26 MeV for
the lightest quark mass M_ps = 469 MeV. Effect of flavor SU(3) symmetry
breaking on the H-dibaryon is estimated by solving the coupled-channel
Schrodinger equation for Lambda Lambda - N Xi - Sigma Sigma with the physical
baryon masses and the potential matrix obtained in the SU(3) limit: a resonant
H-dibaryon is found between Lambda Lambda and N Xi thresholds in this
treatment.Comment: 22 pages, 11 figures, Version accepted to publish on Nucl. Phys.
Thermal fluctuations of gauge fields and first order phase transitions in color superconductivity
We study the effects of thermal fluctuations of gluons and the diquark
pairing field on the superconducting-to-normal state phase transition in a
three-flavor color superconductor, using the Ginzburg-Landau free energy. At
high baryon densities, where the system is a type I superconductor, gluonic
fluctuations, which dominate over diquark fluctuations, induce a cubic term in
the Ginzburg-Landau free energy, as well as large corrections to quadratic and
quartic terms of the order parameter. The cubic term leads to a relatively
strong first order transition, in contrast with the very weak first order
transitions in metallic type I superconductors. The strength of the first order
transition decreases with increasing baryon density. In addition gluonic
fluctuations lower the critical temperature of the first order transition. We
derive explicit formulas for the critical temperature and the discontinuity of
the order parameter at the critical point. The validity of the first order
transition obtained in the one-loop approximation is also examined by
estimating the size of the critical region.Comment: 12 pages, 4 figures, final version published in Phys. Rev.
Gauge Theory of Composite Fermions: Particle-Flux Separation in Quantum Hall Systems
Fractionalization phenomenon of electrons in quantum Hall states is studied
in terms of U(1) gauge theory. We focus on the Chern-Simons(CS) fermion
description of the quantum Hall effect(QHE) at the filling factor
, and show that the successful composite-fermions(CF) theory
of Jain acquires a solid theoretical basis, which we call particle-flux
separation(PFS). PFS can be studied efficiently by a gauge theory and
characterized as a deconfinement phenomenon in the corresponding gauge
dynamics. The PFS takes place at low temperatures, , where
each electron or CS fermion splinters off into two quasiparticles, a fermionic
chargeon and a bosonic fluxon. The chargeon is nothing but Jain's CF, and the
fluxon carries units of CS fluxes. At sufficiently low temperatures , fluxons Bose-condense uniformly and (partly)
cancel the external magnetic field, producing the correlation holes. This
partial cancellation validates the mean-field theory in Jain's CF approach.
FQHE takes place at as a joint effect of (i) integer QHE of
chargeons under the residual field and (ii) Bose condensation of
fluxons. We calculate the phase-transition temperature and the CF
mass. PFS is a counterpart of the charge-spin separation in the t-J model of
high- cuprates in which each electron dissociates into holon and
spinon. Quasiexcitations and resistivity in the PFS state are also studied. The
resistivity is just the sum of contributions of chargeons and fluxons, and
changes its behavior at , reflecting the change of
quasiparticles from chargeons and fluxons at to electrons at
.Comment: 18 pages, 7 figure
ダイリ セイヤクホウ ノ フクスウ セイヤク ヒセンケイ ナップザック モンダイ エノ テキヨウ
It is difficult to solve a class of multi-dimensional nonlinear knapsack problem by optimal solution method. We apply surrogate constraints method to a multi-dimensional nonlinear knapsack problem. Introducing a surrogate multiplier, the multi-dimensional nonlinear knapsack problem can be translated to the surrogate problem, which is one-dimensional nonlinear knapsack problem. The optimal solution of the surrogate problem provides upper bounds of the optimal value of given problem. It is important to obtain upper bounds of the optimal value of given problem in engineering application. The surrogate problem can be solved efficiently by Modular Approach. The computational experiments show that our method gives a high quality upper bonds of the optimal value of given problem
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