641 research outputs found

    Header Attachments Help Save Grain Sorghum at Harvest

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    Damaging winds before and during grain sorghum harvest in South Dakota frequently result in high crop loss due to lodging. One way to avoid lodging is to harvest soon after maturity when grain is at high moisture content. This is acceptable in many areas. But in some areas, such as central South Dakota, many farmers believe they cannot justify the expense of drying equipment and. so they wait for the sorghum to mature naturally which increases possibilities of lodging. An investigation by the Agricultural Engineeering Department at South Dakota State University compared different header attachments on a conventional combine to determine if any could materially reduce crop losses due to lodging. Field losses of various header attachments were evaluated from tests in the fall of 1965 and 1966 at the Agricultural Engineering Experiment Station Research Farm near Brookings. The attachment which resulted in the lowest grain loss was then evaluated economically to determine if ownership could be justified under South Dakota conditions

    Some Applications of Thermal Field Theory to Quark-Gluon Plasma

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    The lecture provides a brief introduction of thermal field theory within imaginary time formalism, the Hard Thermal Loop perturbation theory and some of its application to the physics of the quark-gluon plasma, possibly created in relativistic heavy ion collisions.Comment: 17 pages, 12 figures : Lectures given in "Workshop on Hadron Physics" during March 7-17, 2005, Puri, Indi

    Sigurðar saga fóts (The Saga of Sigurðr Foot): A Translation

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    This is the first English translation of the short Icelandic romance Sigurðar saga fóts, with an introduction presenting the evidence for its dating and immediate literary context. Like most Icelandic romances, Sigurðar saga is a bridal-quest story; the support of a foster-brother is key to the hero winning the bride; and the foster-brothers start out as opponents before recognising their mutual excellence and swearing foster-brotherhood. Uniquely, however, the men who become foster-brothers begin by competing for the same bride (Signý): the eponymous Sigurðr fótr wins Signý only because Ásmundr gives her to him in exchange for foster-brotherhood. Ásmundr’s decision can be read as demonstrating with unusual starkness the superior importance in much Icelandic romance of homosocial relationships over heterosexual ones, giving the saga a certain paradigmatic status. Translating the saga in an open-access forum and reconstructing its literary context will, we hope, encourage further analyses

    Sigurðar saga fóts (The Saga of Sigurðr Foot): A Translation

    Get PDF
    This is the first English translation of the short Icelandic romance Sigurðar saga fóts, with an introduction presenting the evidence for its dating and immediate literary context. Like most Icelandic romances, Sigurðar saga is a bridal-quest story; the support of a foster-brother is key to the hero winning the bride; and the foster-brothers start out as opponents before recognising their mutual excellence and swearing foster-brotherhood. Uniquely, however, the men who become foster-brothers begin by competing for the same bride (Signý): the eponymous Sigurðr fótr wins Signý only because Ásmundr gives her to him in exchange for foster-brotherhood. Ásmundr’s decision can be read as demonstrating with unusual starkness the superior importance in much Icelandic romance of homosocial relationships over heterosexual ones, giving the saga a certain paradigmatic status. Translating the saga in an open-access forum and reconstructing its literary context will, we hope, encourage further analyses

    Quench Induced Vortices in the Symmetry Broken Phase of Liquid 4^4He

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    Motivated by the study of cosmological phase transitions, our understanding of the formation of topological defects during spontaneous symmetry-breaking and the associated non-equilibrium field theory has recently changed. Experiments have been performed in superfluid 4^4He to test the new ideas involved. In particular, it has been observed that a vortex density is seen immediately after pressure quenches from just below the λ\lambda transition. We discuss possible interpretations of these vortices, conclude they are consistent with our ideas of vortex formation and propose a modification of the original experiments.Comment: 29 pages, RevTeX with one EPS figur

    The non-convex shape of (234) Barbara, the first Barbarian

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    Asteroid (234) Barbara is the prototype of a category of asteroids that has been shown to be extremely rich in refractory inclusions, the oldest material ever found in the Solar System. It exhibits several peculiar features, most notably its polarimetric behavior. In recent years other objects sharing the same property (collectively known as "Barbarians") have been discovered. Interferometric observations in the mid-infrared with the ESO VLTI suggested that (234) Barbara might have a bi-lobated shape or even a large companion satellite. We use a large set of 57 optical lightcurves acquired between 1979 and 2014, together with the timings of two stellar occultations in 2009, to determine the rotation period, spin-vector coordinates, and 3-D shape of (234) Barbara, using two different shape reconstruction algorithms. By using the lightcurves combined to the results obtained from stellar occultations, we are able to show that the shape of (234) Barbara exhibits large concave areas. Possible links of the shape to the polarimetric properties and the object evolution are discussed. We also show that VLTI data can be modeled without the presence of a satellite.Comment: 10 pages, 6 figure

    Mid-infrared circumstellar emission of the long-period Cepheid l Carinae resolved with VLTI/MATISSE

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    Context. The nature of circumstellar envelopes (CSEs) around Cepheids is a matter of ongoing debate. The physical origin of their infrared (IR) excess could be shown to either be made up of a shell of ionized gas, a dust envelope, or a combination of both.Aims. This study is aimed at constraining the geometry and the IR excess of the environment of the bright long-period Cepheid l Car (P = 35.5 days) at mid-IR wavelengths in order to understand its physical nature.Methods. We first used photometric observations in various bands (from the visible domain to the infrared) and Spitzer Space Telescope spectroscopy to constrain the IR excess of l Car. Then we analyzed the VLTI/MATISSE measurements at a specific phase of observation in order to determine the flux contribution as well as the size and shape of the environment of the star in the L band. Finally, we tested the hypothesis of a shell of ionized gas in order to model the IR excess.Results. We report the first detection in the L band of a centro-symmetric extended emission around l Car, of about 1.7 R-star in full width at half maximum, producing an excess of about 7.0% in this band.This latter value is used to calibrate the IR excess found when comparing the photometric observations in various bands and quasi-static atmosphere models. In the N band, there is no clear evidence for dust emission from VLTI/MATISSE correlated flux and Spitzer data. On the other side, the modeled shell of ionized gas implies a more compact CSE (1.13 0.02 R-star) that is also fainter (IR excess of 1% in the L band).Conclusions. We provide new evidence supporting a compact CSE for l Car and we demonstrate the capabilities of VLTI/MATISSE for determining common properties of CSEs. While the compact CSE of l Car is likely to be of a gaseous nature, the tested model of a shell of ionized gas is not able to simultaneously reproduce the IR excess and the interferometric observations. Further Galactic Cepheid observations with VLTI/MATISSE are necessary for determining the properties of CSEs, which may also depend on both the pulsation period and the evolutionary state of the stars

    A Compact Probe for Beta+Emitting Radiotracer Detection in Suregery, Biopsy, and Medical Diagnostics based on Silicon Photomultipliers

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    We present a new probe for radiotracer detection in vivo. The device is based on silicon photomultipliers coupled with a scintillator and wirelessly compensated for supply voltage and temperature variations. The probe is positron sensitive

    Agronomic Characteristics, Chemical Composition and In vitro Gas Production of Sugarcane Cultivars (Saccharum spp.) for Feeding Ruminants.

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    solids content (BRIX), NDF/BRIX ratio and tons of sucrose/ha, total digestible nutrients, digestible energy, metabolizable energy, net energy and in vitro digestibility of organic matter, crude protein, neutral detergent fiber (NDF) and acid detergent, of digestion and In vitro gas production of nonfibrous carbohydrates, latency time, digestion rate and gas production of fibrous carbohydrates, and in vitro digestibility of organic matter. There was a significant difference between the cultivars regarding the neutral detergent fiber content, in vitro digestibility of organic matter, total digestible nutrients, digestible energy, net energy, degradation rates of fibrous and non-fibrous carbohydrates and latency period. There was a negative correlation between stem percentage and NDF/BRIX and positive correlation between in vitro digestibility of organic matter and total digestible nutrients. The results were submitted to analysis of variance and mean test by Scott-Knott and Pearson's correlation analysis. The statistical program used was SAEG 2000. The RB835486 variety was superior to the other cultivars, as it presented 93.28% of stem, 57.5% of in vitro digestibility of organic matter, NDF / BRIX ratio of 2.68, 43.78% NDF, latency period 2.86h and fibrous carbohydrate degradation rate of 2.26% per hour. Therefore, this cultivar was better indicated for animal feeding between May and July in the State of Mato Grosso, Brazil
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