427 research outputs found

    Effect of Added Lysine to Starter Diets Containing Primarily Zein Protein and Formulated to Provide .14% Tryptophan

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    Corn gluten meal (CGM) is a by-product of the wet milling corn. It is the residue that remains after the bran, germ and starch have been removed and may contain either 41 or 60% crude protein. There is a temptation to use CGM as an alternative to soybean meal (SBM) when the cost of SBM is high. The 60% protein CGM contains a greater quantity of protein and more threonine, sulfur amino acids, and other neutral amino acids than 44% protein SBM. However, SBM contains greater amounts of lysine and tryptophan. Previous studies with growing and finishing swine indicated that tryptophan is limiting in diets containing CGM, even though the diets were formulated to meet the requirements for tryptophan established by the NRC (1988). The objective of this study was to determine if feed intake is maintained for 10 to 20 kg pigs fed low protein diets containing CGM if crystalline L-lysine-HCL (L-LYS) is added to meet the lysine requirement

    Dynamics of earthquake nucleation process represented by the Burridge-Knopoff model

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    Dynamics of earthquake nucleation process is studied on the basis of the one-dimensional Burridge-Knopoff (BK) model obeying the rate- and state-dependent friction (RSF) law. We investigate the properties of the model at each stage of the nucleation process, including the quasi-static initial phase, the unstable acceleration phase and the high-speed rupture phase or a mainshock. Two kinds of nucleation lengths L_sc and L_c are identified and investigated. The nucleation length L_sc and the initial phase exist only for a weak frictional instability regime, while the nucleation length L_c and the acceleration phase exist for both weak and strong instability regimes. Both L_sc and L_c are found to be determined by the model parameters, the frictional weakening parameter and the elastic stiffness parameter, hardly dependent on the size of an ensuing mainshock. The sliding velocity is extremely slow in the initial phase up to L_sc, of order the pulling speed of the plate, while it reaches a detectable level at a certain stage of the acceleration phase. The continuum limits of the results are discussed. The continuum limit of the BK model lies in the weak frictional instability regime so that a mature homogeneous fault under the RSF law always accompanies the quasi-static nucleation process. Duration times of each stage of the nucleation process are examined. The relation to the elastic continuum model and implications to real seismicity are discussed.Comment: Title changed. Changes mainly in abstract and in section 1. To appear in European Physical Journal

    Unitary Fermi gas, epsilon expansion, and nonrelativistic conformal field theories

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    We review theoretical aspects of unitary Fermi gas (UFG), which has been realized in ultracold atom experiments. We first introduce the epsilon expansion technique based on a systematic expansion in terms of the dimensionality of space. We apply this technique to compute the thermodynamic quantities, the quasiparticle spectrum, and the critical temperature of UFG. We then discuss consequences of the scale and conformal invariance of UFG. We prove a correspondence between primary operators in nonrelativistic conformal field theories and energy eigenstates in a harmonic potential. We use this correspondence to compute energies of fermions at unitarity in a harmonic potential. The scale and conformal invariance together with the general coordinate invariance constrains the properties of UFG. We show the vanishing bulk viscosities of UFG and derive the low-energy effective Lagrangian for the superfluid UFG. Finally we propose other systems exhibiting the nonrelativistic scaling and conformal symmetries that can be in principle realized in ultracold atom experiments.Comment: 44 pages, 15 figures, contribution to Lecture Notes in Physics "BCS-BEC crossover and the Unitary Fermi Gas" edited by W. Zwerge

    A perturbative approach to BB decays into two π\pi mesons

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    The modified perturbative approach in which transverse degrees of freedom as well as Sudakov suppressions are taken into account, is applied to BB decays into two π\pi mesons. The influence of various model parameters (CKM matrix elements, BB decay constant, mesonic wave functions) on the results as well as short distance corrections to the weak Hamiltonian are discussed in some detail. The perturbative contributions to the BB decays yield branching ratios of the order of 107    10610^{-7}\;-\;10^{-6} which values are well below the upper limit for the Bˉ0π+π\bar{B}^0\to\pi^+\pi^- branching ratio as measured by CLEO.Comment: 26 pages, RevTex, 6 figures appended (compressed and uuencode using 'uufiles'

    Threshold Electrodisintegration of ^3He

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    Cross sections were measured for the near-threshold electrodisintegration of ^3He at momentum transfer values of q=2.4, 4.4, and 4.7 fm^{-1}. From these and prior measurements the transverse and longitudinal response functions R_T and R_L were deduced. Comparisons are made against previously published and new non-relativistic A=3 calculations using the best available NN potentials. In general, for q<2 fm^{-1} these calculations accurately predict the threshold electrodisintegration of ^3He. Agreement at increasing q demands consideration of two-body terms, but discrepancies still appear at the highest momentum transfers probed, perhaps due to the neglect of relativistic dynamics, or to the underestimation of high-momentum wave-function components.Comment: 9 pages, 7 figures, 1 table, REVTEX4, submitted to Physical Review

    Benchmark Test Calculation of a Four-Nucleon Bound State

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    In the past, several efficient methods have been developed to solve the Schroedinger equation for four-nucleon bound states accurately. These are the Faddeev-Yakubovsky, the coupled-rearrangement-channel Gaussian-basis variational, the stochastic variational, the hyperspherical variational, the Green's function Monte Carlo, the no-core shell model and the effective interaction hyperspherical harmonic methods. In this article we compare the energy eigenvalue results and some wave function properties using the realistic AV8' NN interaction. The results of all schemes agree very well showing the high accuracy of our present ability to calculate the four-nucleon bound state.Comment: 17 pages, 1 figure

    Large-space shell-model calculations for light nuclei

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    An effective two-body interaction is constructed from a new Reid-like NNNN potential for a large no-core space consisting of six major shells and is used to generate the shell-model properties for light nuclei from AA=2 to 6. (For practical reasons, the model space is partially truncated for AA=6.) Binding energies and other physical observables are calculated and compare favorably with experiment.Comment: prepared using LaTex, 21 manuscript pages, no figure

    Avalanches and the Renormalization Group for Pinned Charge-Density Waves

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    The critical behavior of charge-density waves (CDWs) in the pinned phase is studied for applied fields increasing toward the threshold field, using recently developed renormalization group techniques and simulations of automaton models. Despite the existence of many metastable states in the pinned state of the CDW, the renormalization group treatment can be used successfully to find the divergences in the polarization and the correlation length, and, to first order in an ϵ=4d\epsilon = 4-d expansion, the diverging time scale. The automaton models studied are a charge-density wave model and a ``sandpile'' model with periodic boundary conditions; these models are found to have the same critical behavior, associated with diverging avalanche sizes. The numerical results for the polarization and the diverging length and time scales in dimensions d=2,3d=2,3 are in agreement with the analytical treatment. These results clarify the connections between the behaviour above and below threshold: the characteristic correlation lengths on both sides of the transition diverge with different exponents. The scaling of the distribution of avalanches on the approach to threshold is found to be different for automaton and continuous-variable models.Comment: 29 pages, 11 postscript figures included, REVTEX v3.0 (dvi and PS files also available by anonymous ftp from external.nj.nec.com in directory /pub/alan/cdwfigs

    Resonances in the three-neutron system

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    A study of 3-body resonances has been performed in the framework of configuration space Faddeev equations. The importance of keeping a sufficient number of terms in the asymptotic expansion of the resonance wave function is pointed out. We investigated three neutrons interacting in selected force components taken from realistic nn forces.Comment: 38 pages, 11 tables, 4 figure

    The three-nucleon bound state using realistic potential models

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    The bound states of 3^3H and 3^3He have been calculated using the Argonne v18v_{18} plus the Urbana three-nucleon potential. The isospin T=3/2T=3/2 state have been included in the calculations as well as the nn-pp mass difference. The 3^3H-3^3He mass difference has been evaluated through the charge dependent terms explicitly included in the two-body potential. The calculations have been performed using two different methods: the solution of the Faddeev equations in momentum space and the expansion on the correlated hyperspherical harmonic basis. The results are in agreement within 0.1% and can be used as benchmark tests. Results for the CD-Bonn interaction are also presented. It is shown that the 3^3H and 3^3He binding energy difference can be predicted model independently.Comment: 5 pages REVTeX 4, 1 figures, 6 table
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