1,890 research outputs found

    DETERMINANTS OF WHOLESALE BEEF-CUT PRICES

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    Key determinants of monthly wholesale prices for 12 beef cuts include the quantity of the specific cut, stickiness in prices, marketing costs, quantities of pork and chicken, and seasonality. Seasonal patterns across the respective cuts are very different. Relative to the price in December, prices at the wholesale level in other months can be as much as 6 percent lower to as much as 21 percent higher.Wholesale prices, Beef cuts, Seasonality, Demand and Price Analysis, Livestock Production/Industries,

    Individual limb mechanical analysis of gait following stroke

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    The step-to-step transition of walking requires significant mechanical and metabolic energy to redirect the center of mass. Inter-limb mechanical asymmetries during the step-to-step transition may increase overall energy demands and require compensation during single-support. The purpose of this study was to compare individual limb mechanical gait asymmetries during the step-to-step transitions, single-support and over a complete stride between two groups of individuals following stroke stratified by gait speed (≥0.8 m/s o

    Federal Market Orders: Present and Potential Uses

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    Orbital properties of an unusually low-mass sdB star in a close binary system with a white dwarf

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    We have used 605 days of photometric data from the Kepler spacecraft to study KIC 6614501, a close binary system with an orbital period of 0.157 497 47(25) days (3.779 939 h), that consists of a low-mass subdwarf B (sdB) star and a white dwarf (WD). As seen in many other similar systems, the gravitational field of the WD produces an ellipsoidal deformation of the sdB which appears in the light curve as a modulation at two times the orbital frequency. The ellipsoidal deformation of the sdB implies that the system has a maximum inclination of ∼40°, with i ≈ 20° being the most likely. The orbital radial velocity (RV) of the sdB star is high enough to produce a Doppler beaming effect with an amplitude of 432 ± 5 ppm, clearly visible in the folded light curve. The photometric amplitude that we obtain, K1 = 85.8 km s-1, is ∼12 per cent less than the spectroscopic RV amplitude of 97.2 ± 2.0 km s-1. The discrepancy is due to the photometric contamination from a close object at about 5 arcsec north-west of KIC 6614501, which is difficult to remove. The atmospheric parameters of the sdB star, Teff = 23 700 ± 500 K and log g = 5.70 ± 0.10, imply that it is a rare object below the extreme horizontal branch (EHB), similar to HD 188112. The comparison with different evolutionary tracks suggests a mass between ∼0.18 and ∼0.25 M⊙, too low to sustain core helium burning. If the mass was close to 0.18-0.19 M⊙, the star could be already on the final He-core WD cooling track. A higher mass, up to ∼0.25 M⊙, would be compatible with a He-core WD progenitor undergoing a cooling phase in a H-shell flash loop. A third possibility, with a mass between ∼0.32 and ∼0.40 M⊙, cannot be excluded and would imply that the sdB is a ‘normal\u27 (but with an unusually low mass) EHB star burning He in its core. In all these different scenarios, the system is expected to merge in less than 3.1 Gyr due to gravitational wave radiation

    Three ways to solve the orbit of KIC11558725: a 10 day beaming sdB+WD binary with a pulsating subdwarf

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    The recently discovered subdwarf B (sdB) pulsator KIC11558725 features a rich g-mode frequency spectrum, with a few low-amplitude p-modes at short periods, and is a promising target for a seismic study aiming to constrain the internal structure of this star, and of sdB stars in general. We have obtained ground-based spectroscopic Balmer-line radial-velocity measurements of KIC11558725, spanning the 2010 and 2011 observing seasons. From these data we have discovered that KIC11558725 is a binary with period P=10.05 d, and that the radial-velocity amplitude of the sdB star is 58 km/s. Consequently the companion of the sdB star has a minimum mass of 0.63 M\odot, and is therefore most likely an unseen white dwarf. We analyse the near-continuous 2010-2011 Kepler light curve to reveal orbital Doppler-beaming light variations at the 238 ppm level, which is consistent with the observed spectroscopic orbital radial-velocity amplitude of the subdwarf. We use the strongest 70 pulsation frequencies in the Kepler light curve of the subdwarf as clocks to derive a third consistent measurement of the orbital radial-velocity amplitude, from the orbital light-travel delay. We use our high signal-to-noise average spectra to study the atmospheric parameters of the sdB star, deriving Teff = 27 910K and log g = 5.41 dex, and find that carbon, nitrogen and oxygen are underabundant relative to the solar mixture. Furthermore, we extract more than 160 significant frequencies from the Kepler light curve. We investigate the pulsation frequencies for expected period spacings and rotational splittings. We find period-spacing sequences of spherical-harmonic degrees \ell=1 and \ell=2, and we associate a large fraction of the g-modes in KIC11558725 with these sequences. From frequency splittings we conclude that the subdwarf is rotating subsynchronously with respect to the orbit

    The performance of the MROI fast tip-tilt correction system

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    The fast tip-tilt (FTT) correction system for the Magdalena Ridge Observatory Interferometer (MROI) is being developed by the University of Cambridge. The design incorporates an EMCCD camera protected by a thermal enclosure, optical mounts with passive thermal compensation, and control software running under Xenomai real-time Linux. The complete FTT system is now undergoing laboratory testing prior to being installed on the first MROI unit telescope in the fall of 2014. We are following a twin-track approach to testing the closed-loop performance: tracking tip-tilt perturbations introduced by an actuated flat mirror in the laboratory, and undertaking end-to-end simulations that incorporate realistic higher-order atmospheric perturbations. We report test results that demonstrate (a) the high stability of the entire opto-mechanical system, realized with a completely passive design; and (b) the fast tip-tilt correction performance and limiting sensitivity. Our preliminary results in both areas are close to those needed to realise the ambitious stability and sensitivity goals of the MROI which aims to match the performance of current natural guide star adaptive optics systems.Previously funded by the Naval Research Laboratory (under Agreement No. N00173-01-2-C902), MROI is currently funded by the US Department of Transportation, the State of New Mexico and by New Mexico Tech

    Superdeformation in 198^{198}Po

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    The 174^{174}Yb(29^{29}Si,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in 198^{198}Po. Resulting γ\gamma rays were observed with Gammasphere. A weakly-populated superdeformed band of 10 γ\gamma-ray transitions was found and has been assigned to 198^{198}Po. This is the first observation of a SD band in the A190A \approx 190 region in a nucleus with Z>83Z > 83. The J(2){\cal J}^{(2)} of the new band is very similar to those of the yrast SD bands in 194^{194}Hg and 196^{196}Pb. The intensity profile suggests that this band is populated through states close to where the SD band crosses the yrast line and the angular momentum at which the fission process dominates.Comment: 10 pages, revtex, 2 figs. available on request, submitted to Phys. Rev. C. (Rapid Communications
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