2,582 research outputs found

    Field Beans and Spring Wheat as Whole Crop Silage: Yield, Chemical Composition and Fermentation Characteristics

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    There has been an increasing interest in field beans (Vicia faba L.) in recent years because of its N-fixating ability. The objective of this study was to compare the yield, chemical composition and fermentation characteristics of field bean/spring wheat as whole-crop silage ensiled with and without an additive. The crop was drilled on 27 May 2003 at a seed rate of 205 kg/ha field beans and 68 kg/ha spring wheat. The crop was harvested at four different growth stages (Zadoks et al., 1974); end of blooming, (stage 69), when 50% of the pods had reached full length, (stage 75), pods fully formed, (stage 79) and when 10% of the pods are filled (stage 81). Yield and botanical composition were evaluated. Samples of the forage were analysed for dry matter (DM) and chemical composition at harvest. Forage, at stages 75, 79 and 81 was wilted overnight then chopped (20 mm) and ensiled in 10 kg silos. Half the forage was ensiled untreated (control). The other half was treated with PROENS (60-66% formic acid and 23-29% propionic acid, Perstorp Speciality Chemicals, Sweden) applied at a rate of 6 l/t fresh matter. The silos were incubated for a period of 90 d and then analysed for DM, chemical composition and fermentation characteristics

    Whole Crop Cereal Silage in Dairy Production

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    Whole-crop cereal silages (WCCS) are used to some extent in Sweden, but knowledge about the use of this feed for high yielding dairy cows is scarce. The crop is often harvested at different stages of maturity, from heading to yellow ripeness, which gives forages that differ in chemical composition. The purpose of this trial was to compare intake and milk production of dairy cows fed a WCCS based on barley harvested at three different stages of maturity

    Spin distribution of nuclear levels using static path approximation with random-phase approximation

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    We present a thermal and quantum-mechanical treatment of nuclear rotation using the formalism of static path approximation (SPA) plus random-phase approximation (RPA). Naive perturbation theory fails because of the presence of zero-frequency modes due to dynamical symmetry breaking. Such modes lead to infrared divergences. We show that composite zero-frequency excitations are properly treated within the collective coordinate method. The resulting perturbation theory is free from infrared divergences. Without the assumption of individual random spin vectors, we derive microscopically the spin distribution of the level density. The moment of inertia is thereby related to the spin-cutoff parameter in the usual way. Explicit calculations are performed for 56^Fe; various thermal properties are discussed. In particular, we demonstrate that the increase of the moment of inertia with increasing temperature is correlated with the suppression of pairing correlations.Comment: 12 pages, 8 figures, accepted for publication in Physical Review

    Density of states of helium droplets

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    Accurate analytical expressions for the state densities of liquid He-4 droplets are derived, incorporating the ripplon and phonon degrees of freedom. The microcanonical temperature and the ripplon angular momentum level density are also evaluated. The approach is based on inversions and systematic expansions of canonical thermodynamic properties.Comment: 20 pages, 5 figure

    On Deusons or Deuteronlike Meson-Meson Bound States

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    The systematics of deuteronlike two-meson bound states, {\it deusons}, is discussed. Previous arguments that many of the present non-qqˉq\bar q states are such states are elaborated including, in particular, the tensor potential. For pseudoscalar states the important observation is made that the centrifugal barrier from the P-wave can be overcome by the 1/r21/r^2 and 1/r31/r^3 terms of the tensor potential. In the heavy meson sector one-pion exchange alone is strong enough to form at least deuteron-like BBˉB\bar B^* and BBˉB^*\bar B^* composites bound by approximately 50 MeV, while DDˉD\bar D^* and DDˉD^*\bar D^* states are expected near the threshold.Comment: Invited talk at the Hadron93 International Conf. on Hadron Spectroscopy, Como, Italy 22.-25.6. 1993. 5 pages in LATEX HU-SEFT R 1993-13

    Neutrino induced threshold production of two pions and N^*(1440) electroweak form factors

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    We study the threshold production of two pions induced by neutrinos in nucleon targets. The contribution of nucleon, pion and contact terms are calculated using a chiral Lagrangian. The contribution of the Roper resonance, neglected in earlier studies, has also been taken into account. The numerical results for the cross sections are presented and compared with the available experimental data. It has been found that in the two pion channels with π+π\pi^+\pi^- and π0π0\pi^0\pi^0 in the final state, the contribution of the N(1440)N^*(1440) is quite important and could be used to determine the N(1440)N^*(1440) electroweak transition form factors if experimental data with better statistics become available in the future.Comment: This version corrects a mistake on the helicity amplitudes sign. Additional comments on resonance-background relative sign are added. Other minor corrections. Matches published version. 17 pages, 7 figure

    Hadron properties in the nuclear medium

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    The QCD vacuum shows the dynamical breaking of chiral symmetry. In the hot/dense QCD medium, the chiral order parameter such as is expected to change as function of temperature TT and density ρ\rho of the medium, and its experimental detection is one of the main challenges in modern hadron physics. In this article, we discuss theoretical expectations for the in-medium hadron spectra associated with partial restoration of chiral symmetry and the current status of experiments with an emphasis on the measurements of properties of mesons produced in near-ground-state nuclei.Comment: 40 pages, submitted to Reviews of Modern Physic

    Performance of the neutron polarimeter NPOL3 for high resolution measurements

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    We describe the neutron polarimeter NPOL3 for the measurement of polarization transfer observables DijD_{ij} with a typical high resolution of \sim300 keV at TnT_n \simeq 200 MeV. The NPOL3 system consists of three planes of neutron detectors. The first two planes for neutron polarization analysis are made of 20 sets of one-dimensional position-sensitive plastic scintillation counters with a size of 100 cm ×\times 10 cm ×\times 5 cm, and they cover the area of 100 ×\times 100 cm2\mathrm{cm}^2. The last plane for detecting doubly scattered neutrons or recoiled protons is made of the two-dimensional position-sensitive liquid scintillation counter with a size of 100 cm ×\times 100 cm ×\times 10 cm. The effective analyzing powers Ay;effA_{y;\mathrm{eff}} and double scattering efficiencies ϵD.S.\epsilon_{\mathrm{D.S.}} were measured by using the three kinds of polarized neutrons from the 2H(p,n)pp{}^{2}{\rm H}(\vec{p},\vec{n})pp, 6Li(p,n)6Be(g.s.){}^{6}{\rm Li}(\vec{p},\vec{n}){}^{6}{\rm Be}(\mathrm{g.s.}), and 12C(p,n)12N(g.s.){}^{12}{\rm C}(\vec{p},\vec{n}){}^{12}{\rm N}(\mathrm{g.s.}) reactions at TpT_p = 198 MeV. The performance of NPOL3 defined as ϵD.S.(Ay;eff)2\epsilon_{\mathrm{D.S.}}(A_{y;\mathrm{eff}})^2 are similar to that of the Indiana Neutron POLarimeter (INPOL) by taking into account for the counter configuration difference between these two neutron polarimeters.Comment: 28 pages, 18 figures, submitted to Nucl. Instrum. Methods Phys. Res.

    Low-noise photodiode-amplifier circuit

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