10,835 research outputs found

    Reliable solid-state circuits Semiannual report no. 2, Jun. 1 - Nov. 30, 1965

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    Pulse width modulator and other microminiaturized electronic equipment for space age application

    Quantum Monte Carlo Calculations of A6A\leq6 Nuclei

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    The energies of 3H^{3}H, 3He^{3}He, and 4He^{4}He ground states, the 32{\frac{3}{2}}^{-} and 12{\frac{1}{2}}^{-} scattering states of 5He^{5}He, the ground states of 6He^{6}He, 6Li^{6}Li, and 6Be^{6}Be and the 3+3^{+} and 0+0^{+} excited states of 6Li^{6}Li have been accurately calculated with the Green's function Monte Carlo method using realistic models of two- and three-nucleon interactions. The splitting of the A=3A=3 isospin T=12T=\frac{1}{2} and A=6A=6 isospin T=1T=1, Jπ=0+J^{\pi} = 0^{+} multiplets is also studied. The observed energies and radii are generally well reproduced, however, some definite differences between theory and experiment can be identified.Comment: 12 pages, 1 figur

    Comparative Performance of Crossbred Heifer Calves Fed MGA or Implanted with Synovex-H

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    Numerous studies have demonstrated the substantial economic benefit of using hormonal growth stimulants with feedlot heifers. The feed additive melengestrol acetate (MGA) and ear implants such as Synovex-H are commonly used for this purpose. Consistent improvements in both rate of gain and feed efficiency have been shown with these growth promotants. However, relatively few trials have directly compared MGA and Synovex-H under controlled conditions. Thus, the major objective of this study was to determine merit of these two growth stimulants. In addition, this study presented an opportunity to compare the feedlot performance and carcass characteristics of two different groups of crossbred heifers

    Feedlot Performance of Yearling Heifers Fed Pro-Sil Treated on Urea Supplemented Corn Silage

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    The objective of this study was to evaluate the performance of cattle fed Pro-Sil treated corn silage or untreated (control) corn silage supplemented with a urea-based protein supplement at time of feeding. In addition, plastic horizontal Silopress silage bags were used to store the Pro-Sil treated and control corn silages in order to gain experience with this silage storage method

    Mean-field calculations of quasi-elastic responses in 4He

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    We present calculations of the quasi-elastic responses functions in 4He based upon a mean-field model used to perform analogous calculations in heavier nuclei. The meson exchange current contribution is small if compared with the results of calculations where short-range correlations are explicitly considered. It is argued that the presence of these correlations in the description of the nuclear wave functions is crucial to make meson exchange current effects appreciable.Comment: uuencoded file containing 7 LaTex peges plus 3 ps figures. To be published in Physical Review

    Relativistic calculation of the triton binding energy and its implications

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    First results for the triton binding energy obtained from the relativistic spectator or Gross equation are reported. The Dirac structure of the nucleons is taken into account. Numerical results are presented for a family of realistic OBE models with off-shell scalar couplings. It is shown that these off-shell couplings improve both the fits to the two-body data and the predictions for the binding energy.Comment: 5 pages, RevTeX 3.0, 1 figure (uses epsfig.sty

    Nuclear Theory and Science of the Facility for Rare Isotope Beams

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    The Facility for Rare Isotope Beams (FRIB) will be a world-leading laboratory for the study of nuclear structure, reactions and astrophysics. Experiments with intense beams of rare isotopes produced at FRIB will guide us toward a comprehensive description of nuclei, elucidate the origin of the elements in the cosmos, help provide an understanding of matter in neutron stars, and establish the scientific foundation for innovative applications of nuclear science to society. FRIB will be essential for gaining access to key regions of the nuclear chart, where the measured nuclear properties will challenge established concepts, and highlight shortcomings and needed modifications to current theory. Conversely, nuclear theory will play a critical role in providing the intellectual framework for the science at FRIB, and will provide invaluable guidance to FRIB's experimental programs. This article overviews the broad scope of the FRIB theory effort, which reaches beyond the traditional fields of nuclear structure and reactions, and nuclear astrophysics, to explore exciting interdisciplinary boundaries with other areas. \keywords{Nuclear Structure and Reactions. Nuclear Astrophysics. Fundamental Interactions. High Performance Computing. Rare Isotopes. Radioactive Beams.Comment: 20 pages, 7 figure

    Driven lattice glass as a ratchet and pawl machine

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    Boundary-induced transport in particle systems with anomalous diffusion exhibits rectification, negative resistance, and hysteresis phenomena depending on the way the drive acts on the boundary. The solvable case of a 1D system characterized by a power-law diffusion coefficient and coupled to two particles reservoirs at different chemical potential is examined. In particular, it is shown that a microscopic realisation of such a diffusion model is provided by a 3D driven lattice-gas with kinetic constraints, in which energy barriers are absent and the local microscopic reversibility holds.Comment: 12 pages, 4 figures, minor change

    Self-Similarity of Friction Laws

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    The change of the friction law from a mesoscopic level to a macroscopic level is studied in the spring-block models introduced by Burridge-Knopoff. We find that the Coulomb law is always scale invariant. Other proposed scaling laws are only invariant under certain conditions.}Comment: Plain TEX. Figures not include

    Toward a complete theory for predicting inclusive deuteron breakup away from stability

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    We present an account of the current status of the theoretical treatment of inclusive (d,p)(d,p) reactions in the breakup-fusion formalism, pointing to some applications and making the connection with current experimental capabilities. Three independent implementations of the reaction formalism have been recently developed, making use of different numerical strategies. The codes also originally relied on two different but equivalent representations, namely the prior (Udagawa-Tamura, UT) and the post (Ichimura-Austern-Vincent, IAV) representations. The different implementations have been benchmarked, and then applied to the Ca isotopic chain. The neutron-Ca propagator is described in the Dispersive Optical Model (DOM) framework, and the interplay between elastic breakup (EB) and non-elastic breakup (NEB) is studied for three Ca isotopes at two different bombarding energies. The accuracy of the description of different reaction observables is assessed by comparing with experimental data of (d,p)(d,p) on 40,48^{40,48}Ca. We discuss the predictions of the model for the extreme case of an isotope (60^{60}Ca) currently unavailable experimentally, though possibly available in future facilities (nominally within production reach at FRIB). We explore the use of (d,p)(d,p) reactions as surrogates for (n,γ)(n,\gamma) processes, by using the formalism to describe the compound nucleus formation in a (d,pγ)(d,p\gamma) reaction as a function of excitation energy, spin, and parity. The subsequent decay is then computed within a Hauser-Feshbach formalism. Comparisons between the (d,pγ)(d,p\gamma) and (n,γ)(n,\gamma) induced gamma decay spectra are discussed to inform efforts to infer neutron captures from (d,pγ)(d,p\gamma) reactions. Finally, we identify areas of opportunity for future developments, and discuss a possible path toward a predictive reaction theory
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