5,553 research outputs found

    Review of fan efficiency for meat chicken sheds

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    This report is all about ventilation fans (exhaust fans) used on tunnel ventilated meat chicken sheds. The report has two themes: reviewing the performance and efficiency of new fans currently available in Australia; and identifying methods to assess fans and help to identify fans that are underperforming

    ‘How to’ guide for measuring fan performance and efficiency in meat chicken sheds

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    This ‘how to’ guide provides readers with method to measure fan performance and energy efficiency of fans installed in meat chicken sheds. These methods are also useful for identifying fans that are under-performing or require maintenance. For more information about fan energy efficiency, a complementary report is available on the RIRDC website ‘Review of fan efficiency in meat chicken sheds’ (RIRDC Publication No. 15/018). A spreadsheet was also developed under this project for comparing and ranking fans against others in terms of energy efficiency, air flow and costs (‘Tunnel Ventilation Fan Comparison Spreadsheet’), and is available on the RIRDC website

    ‘How to’ guide for measuring fan performance and efficiency in meat chicken sheds

    Get PDF
    This ‘how to’ guide provides readers with method to measure fan performance and energy efficiency of fans installed in meat chicken sheds. These methods are also useful for identifying fans that are under-performing or require maintenance. For more information about fan energy efficiency, a complementary report is available on the RIRDC website ‘Review of fan efficiency in meat chicken sheds’ (RIRDC Publication No. 15/018). A spreadsheet was also developed under this project for comparing and ranking fans against others in terms of energy efficiency, air flow and costs (‘Tunnel Ventilation Fan Comparison Spreadsheet’), and is available on the RIRDC website

    Dynamic Behavior of Soils From Field and Laboratory Tests

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    Both geophysical and laboratory tests were used to determine the dynamic shear moduli of medium stiff to hard clays and silts at six sites. The geophysical measurements included conventional downhole tests conducted at low strain levels and modified cross-hole impulse tests conducted over a wide range of strains. Laboratory resonant column and cyclic triaxial tests were performed on soil samples retrieved from borings made at the sites. The results from both the field and laboratory tests of the medium stiff to stiff sols showed fairly good agreement. The laboratory test results of the hard clays and silts, however, were typically half the values of the field tests at corresponding strain levels. This would suggest the need for adjusting the laboratory results performed on hard cohesive soils. Also, the field test results suggest that as soil stiffness increases, the modulus attenuation rate with strain decreases

    Hamiltonians for Reduced Gravity

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    A generalised canonical formulation of gravity is devised for foliations of spacetime with codimension n1n\ge1. The new formalism retains n-dimensional covariance and is especially suited to 2+2 decompositions of spacetime. It is also possible to use the generalised formalism to obtain boundary contributions to the 3+1 Hamiltonian.Comment: 18 pages, revtex, 3 postscript figures include

    The Budding Yeast “Saccharomyces cerevisiae” as a Drug Discovery Tool to Identify Plant-Derived Natural Products with Anti-Proliferative Properties

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    The budding yeast Saccharomyces cerevisiae is a valuable system to study cell-cycle regulation, which is defective in cancer cells. Due to the highly conserved nature of the cell-cycle machinery between yeast and humans, yeast studies are directly relevant to anticancer-drug discovery. The budding yeast is also an excellent model system for identifying and studying antifungal compounds because of the functional conservation of fungal genes. Moreover, yeast studies have also contributed greatly to our understanding of the biological targets and modes of action of bioactive compounds. Understanding the mechanism of action of clinically relevant compounds is essential for the design of improved second-generation molecules. Here we describe our methodology for screening a library of plant-derived natural products in yeast in order to identify and characterize new compounds with anti-proliferative properties

    Genome-scale genetic interactions and cell imaging confirm cytokinesis as deleterious to transient topoisomerase II deficiency in <i>Saccharomyces cerevisiae</i>

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    Topoisomerase II (Top2) is an essential protein that resolves DNA catenations. When Top2 is inactivated, mitotic catastrophe results from massive entanglement of chromosomes. Top2 is also the target of many first-line anticancer drugs, the so-called Top2 poisons. Often, tumors become resistant to these drugs by acquiring hypomorphic mutations in the genes encoding Top2. Here, we have compared the cell cycle and nuclear segregation of two coisogenic Saccharomyces cerevisiae strains carrying top2 thermosensitive alleles that differ in their resistance to Top2 poisons: the broadly-used poison-sensitive top2-4 and the poison-resistant top2-5. Furthermore, we have performed genome-scale synthetic genetic array (SGA) analyses for both alleles under permissive conditions, chronic sublethal Top2 downregulation, and acute, yet transient, Top2 inactivation. We find that slowing down mitotic progression, especially at the time of execution of the mitotic exit network (MEN), protects against Top2 deficiency. In all conditions, genetic protection was stronger in top2-5; this correlated with cell biology experiments in this mutant, whereby we observed destabilization of both chromatin and ultrafine anaphase bridges by execution of MEN and cytokinesis. Interestingly, whereas transient inactivation of the critical MEN driver Cdc15 partly suppressed top2-5 lethality, this was not the case when earlier steps within anaphase were disrupted; i.e., top2-5 cdc14-1. We discuss the basis of this difference and suggest that accelerated progression through mitosis may be a therapeutic strategy to hypersensitize cancer cells carrying hypomorphic mutations in TOP2

    Community-identified strategies to increase physical activity during elementary school recess on an American Indian reservation: A pilot study

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    AbstractThe aim of this study was to determine the effect of an 8-week recess intervention on physical activity levels in children attending elementary school on an American Indian reservation during fall 2013.Physical activity was measured with direct observation in three zones on the playground. Lines were painted on existing pavement in zone 1. Zone 2 had permanent playground equipment and was unchanged. Zone 3 contained fields where bi-weekly facilitators led activities and provided equipment. Pre- to post-changes during recess in sedentary, moderate physical activity, moderate-to-vigorous, and vigorous physical activities were compared within zones.Females physical activity increased in Zone 1 (moderate: 100% increase; moderate-to-vigorous: 83%; vigorous: 74%, p<0.01 for all) and Zone 3 (moderate: 54% increase, p<0.01; moderate-to-vigorous: 48%, p<0.01; vigorous: 40%, p<0.05). Male sedentary activity decreased in Zone 2 (161%, p<0.01). Physical activity changes in Zone 3 were not dependent upon the presence of a facilitator.Simple and low-cost strategies were effective at increasing recess physical activity in females. The findings also suggest that providing children games that are led by a facilitator is not necessary to increase physical activity as long as proper equipment is provided

    Physics of reverse annealing in high-resistivity Chandra ACIS CCDs

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    After launch, the Advanced CCD Imaging Spectrometer (ACIS), a focal plane instrument on the Chandra X-ray Observatory, suffered radiation damage from exposure to soft protons during passages through the Earth's radiation belts. An effect of the damage was to increase the charge transfer inefficiency (CTI) of the front illuminated CCDs. As part of the initial damage assessment, the focal plane was warmed from the operating temperature of -100C to +30C which unexpectedly further increased the CTI. We report results of ACIS CCD irradiation experiments in the lab aimed at better understanding this reverse annealing process. Six CCDs were irradiated cold by protons ranging in energy from 100 keV to 400 keV, and then subjected to simulated bakeouts in one of three annealing cycles. We present results of these lab experiments, compare them to our previous experiences on the ground and in flight, and derive limits on the annealing time constants.Comment: 9 pages, to appear in Proc. SPIE 7021, "High Energy, Optical and Infrared Detectors for Astronomy

    Evolution of speckle during spinodal decomposition

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    Time-dependent properties of the speckled intensity patterns created by scattering coherent radiation from materials undergoing spinodal decomposition are investigated by numerical integration of the Cahn-Hilliard-Cook equation. For binary systems which obey a local conservation law, the characteristic domain size is known to grow in time τ\tau as R=[Bτ]nR = [B \tau]^n with n=1/3, where B is a constant. The intensities of individual speckles are found to be nonstationary, persistent time series. The two-time intensity covariance at wave vector k{\bf k} can be collapsed onto a scaling function Cov(δt,tˉ)Cov(\delta t,\bar{t}), where δt=k1/nBτ2τ1\delta t = k^{1/n} B |\tau_2-\tau_1| and tˉ=k1/nB(τ1+τ2)/2\bar{t} = k^{1/n} B (\tau_1+\tau_2)/2. Both analytically and numerically, the covariance is found to depend on δt\delta t only through δt/tˉ\delta t/\bar{t} in the small-tˉ\bar{t} limit and δt/tˉ1n\delta t/\bar{t} ^{1-n} in the large-tˉ\bar{t} limit, consistent with a simple theory of moving interfaces that applies to any universality class described by a scalar order parameter. The speckle-intensity covariance is numerically demonstrated to be equal to the square of the two-time structure factor of the scattering material, for which an analytic scaling function is obtained for large tˉ.\bar{t}. In addition, the two-time, two-point order-parameter correlation function is found to scale as C(r/(Bnτ12n+τ22n),τ1/τ2)C(r/(B^n\sqrt{\tau_1^{2n}+\tau_2^{2n}}),\tau_1/\tau_2), even for quite large distances rr. The asymptotic power-law exponent for the autocorrelation function is found to be λ4.47\lambda \approx 4.47, violating an upper bound conjectured by Fisher and Huse.Comment: RevTex: 11 pages + 12 figures, submitted to PR
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