53,502 research outputs found

    Amplifier for signal from thin film transducer

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    Electronic circuitry is devised to raise low level signal from platinum film type transducer to sufficient amplitude to trigger oscilloscope or time interval counter. Circuit can be used wherever it is necessary to raise level of low amplitude, low impedance positive polarity pulse source to a 5 or 6 volt level

    Absence of orbital-selective Mott transition in Ca_2-xSr_xRuO4

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    Quasi-particle spectra of the layer perovskite Sr2_2RuO4_4 are calculated within Dynamical Mean Field Theory for increasing values of the on-site Coulomb energy UU. At small UU the planar geometry splits the t2gt_{2g} bands near EFE_F into a wide, two-dimensional dxyd_{xy} band and two narrow, nearly one-dimensional dxz,yzd_{xz,yz} bands. At larger UU, however, the spectral distribution of these states exhibit similar correlation features, suggesting a common metal-insulator transition for all t2gt_{2g} bands at the same critical UU.Comment: 4 pages, 4 figure

    Fatty Acids, α-Tocopherol, β-Carotene and Lutein Contents in Forage Legumes, Forbs, and a Grass-Clover Mixture

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    Fresh forages are an important natural source of vitamins and fatty acids in ruminant diets, and their concentrations in forage species are important for the quality of animal-derived foods such as dairy and meat products. The aims of this study were to obtain novel information on vitamins and fatty acids (FA) in a variety of forage legumes and non-legume forb species compared to a grass−clover mixture and to explore implications for animal-derived products. Seven dicotyledons [four forbs (salad burnet (Sanguisorba minor), caraway (Carum carvi), chicory (Cichorium intybus), and ribwort plantain (Plantago lanceolata)) and three legume species (yellow sweet clover (Melilotus officinalis), lucerne (Medicago sativa), and birdsfoot trefoil (Lotus corniculatus))] and a perennial ryegrass−white clover mixture were investigated in a cutting trial with four harvests (May−October) during 2009 and 2010. The experimental design was a randomized complete block, and analyses of variance were performed. In addition, three other forbs were grown: borage (Borago officinalis), viper’s bugloss (Echium vulgare), and chervil (Anthriscus cerefolium). Lucerne and yellow sweet clover had the lowest α-tocopherol concentrations (21−23 mg kg−1 DM) and salad burnet and ribwort plantain the highest (77−85 mg kg−1 DM); β-carotene concentrations were lowest in lucerne, salad burnet, and yellow sweet clover (26−33 mg kg−1 DM) and highest in caraway, birdsfoot trefoil, and ribwort plantain (56−61 mg kg−1 DM). Total FA concentrations were lowest in lucerne, ribwort plantain, chicory, and yellow sweet clover (15.9−19.3 g kg−1 DM) and highest in caraway and birdsfoot trefoil (15.9−19.3 g kg−1 DM). Birdsfoot trefoil had the highest (53.6 g 100 g−1 FA) and caraway and lucerne the lowest (33.7−35.7 g 100 g−1 FA) proportions of n-3 FA. This study demonstrated higher vitamin concentrations in some forbs compared with major forages such as lucerne and grass−clover, more total FA in salad burnet, caraway, and birdsfoot trefoil than in lucerne, and higher n-3 FA concentrations in all forbs than in lucerne. Opportunities are discussed to develop novel biodiverse pastures for particular product quality characteristics

    Beam impingement angle effects on secondary electron emission characteristics of textured pyrolytic graphite

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    Experimentally determined values of true secondary electron emission and relative values of reflected primary electron yield for untreated and ion-textured pyrolytic graphite over a range of primary electron energy levels and electron beam impingement angles are presented. Information required to develop high efficiency multistage depressed collectors (MDC's) for microwave amplifier traveling-wave tubes for space communication and aircraft applications is provided. To attain the highest possible MDC efficiencies, the electrode surfaces must have low secondary electron emission characteristics. Pyrolytic graphite, a chemically vapor-deposited material, is a particularly promising candidate for this application. The pyrolytic graphite surfaces studied were tested over a range of primary electron beam energies and beam impingement angles from 200 to 2000 eV and direct (0 deg) to near-grazing angles (85 deg), respectively. Surfaces both parallel to and normal to the planes of material deposition were examined. The true secondary electron emission and reflected primary electron yield characteristics of the pyrolytic graphite surfaces are compared to those of sooted control surfaces

    FeederAnt - An autonomous mobile unit feeding outdoor pigs

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    Small robots and the concept of decentralized animal husbandry make it possible to renew the principles of organic agriculture. The farm animals will be able to use the same type of housing and are placed integrated with the fields. This is expected to achieve a better utilization of nutrients and a better survival rate for useful insects and micro organisms. The small fields are flexible and could fit to the variation in soil structure topography. This type of precision agriculture has the possibility of increasing biodiversity. The paper presents the concept of an autonomic feeding system for outdoor piglets. Initial results are presented using a remote controlled feeding unit (a prototype of the FeederAnt) to feed several pens with piglets. The FeederAnt drives into the grass paddocks twice a day and position itself in a new location for each feeding. This will help to distribute the manure from the animals evenly over the grass paddock to prevent point leaching of nutrients. The FeederAnt replaces many stationary feeding tables and reduce the amount of daily manual feeding routines. Further, it is expected that the problem with vermins will be solved since no feed residues will be left within the pens.
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