1,239 research outputs found

    Time resolved fission in metal clusters

    Full text link
    We explore from a theoretical point of view pump and probe (P&P) analysis for fission of metal clusters where probe pulses are generalized to allow for scanning various frequencies. We show that it is possible to measure the time the system needs to develop to scission. This is achieved by a proper choice of both delay and frequency of the probe pulse. A more detailed analysis even allows to access the various intermediate stages of the fission process.Comment: 4 pages, 4 figure

    Use of anabolic implants in calves to increase weaning weight and backgrounding gains

    Get PDF
    The main component of the beef industry in South Carolina is cow/calf operations. Recent advances in implant technology are being utilized to help these producers increase weights at time of sale to feedlots. The objective of this study was to determine how the use of anabolic implants in steer calves at 4 mo of age and at weaning altered weight gain at two different farm locations in South Carolina. Steers ( year 1; n= 161, year 2 n=116) from Edisto REC and Simpson REC were randomly allotted into two treatment groups: 1) no implant or 2) implant at 4 mo of age plus implant at weaning. Weights were obtained at implanting, weaning, and the end of backgrounding. Real-time ultrasound measurements of the ribeye area and fat thickness were collected at the end of the backgrounding period. Data were analyzed with the treatment, location, year, and the interaction in the model. Implanting the steers increased (P\u3c0.001) average daily gains from implanting to weaning, weaning to the end of the backgrounding, and overall by 0.36, 0.15, 0.25 lb/hd/d respectively. Implanting also increased ribeye area by 0.34 in2. Weight and gains of the steers differed by location and year but there were no interactions between location, year, and implant treatment. The use of anabolic implants in steer calves at 4 mo of age and then again at weaning helped to increase weight gain, other desirable carcass traits and produced heavier steers for marketing

    Use of anabolic implants in calves to increase weaning weight and backgrounding gains

    Get PDF
    The main component of the beef industry in South Carolina is cow/calf operations. Recent advances in implant technology are being utilized to help these producers increase weights at time of sale to feedlots. The objective of this study was to determine how the use of anabolic implants in steer calves at 4 mo of age and at weaning altered weight gain at two different farm locations in South Carolina. Steers ( year 1; n= 161, year 2 n=116) from Edisto REC and Simpson REC were randomly allotted into two treatment groups: 1) no implant or 2) implant at 4 mo of age plus implant at weaning. Weights were obtained at implanting, weaning, and the end of backgrounding. Real-time ultrasound measurements of the ribeye area and fat thickness were collected at the end of the backgrounding period. Data were analyzed with the treatment, location, year, and the interaction in the model. Implanting the steers increased (P\u3c0.001) average daily gains from implanting to weaning, weaning to the end of the backgrounding, and overall by 0.36, 0.15, 0.25 lb/hd/d respectively. Implanting also increased ribeye area by 0.34 in2. Weight and gains of the steers differed by location and year but there were no interactions between location, year, and implant treatment. The use of anabolic implants in steer calves at 4 mo of age and then again at weaning helped to increase weight gain, other desirable carcass traits and produced heavier steers for marketing

    Correlated ab-initio calculations for ground-state properties of II-VI semiconductors

    Full text link
    Correlated ab-initio ground-state calculations, using relativistic energy-consistent pseudopotentials, are performed for six II-VI semiconductors. Valence (ns,npns,np) correlations are evaluated using the coupled cluster approach with single and double excitations. An incremental scheme is applied based on correlation contributions of localized bond orbitals and of pairs and triples of such bonds. In view of the high polarity of the bonds in II-VI compounds, we examine both, ionic and covalent embedding schemes for the calculation of individual bond increments. Also, a partitioning of the correlation energy according to local ionic increments is tested. Core-valence (nsp,(n−1)dnsp,(n-1)d) correlation effects are taken into account via a core-polarization potential. Combining the results at the correlated level with corresponding Hartree-Fock data we recover about 94% of the experimental cohesive energies; lattice constants are accurate to \sim 1%; bulk moduli are on average 10% too large compared with experiment.Comment: 10 pages, twocolumn, RevTex, 3 figures, accepted Phys. Rev.

    Medicinal plant preparations administered by botswana traditional health practitioners for treatment of worm infections show anthelmintic activities

    Get PDF
    Schistosomiasis and soil-transmitted helminths are some of the priority neglected tropical diseases (NTDs) targeted for elimination by the World Health Organization (WHO). They are prevalent in Botswana and although Botswana has begun mass drug administration with the hope of eliminating soil-transmitted helminths as a public health problem, the prevalence of schistosomiasis does not meet the threshold required to warrant large-scale interventions. Although Botswana has a modern healthcare system, many people in Botswana rely on traditional medicine to treat worm infections and schistosomiasis. In this study, ten plant species used by traditional health practitioners against worm infections were collected and tested against Ancylostoma ceylanicum (zoonotic hookworm), Heligmosomoides polygyrus (roundworm of rodents), Necator americanus (New World hookworm), Schistosoma mansoni (blood fluke) [adult and newly transformed schistosomula (NTS)], Strongyloides ratti (threadworm) and Trichuris muris (nematode parasite of mice) in vitro. Extracts of two plants, Laphangium luteoalbum and Commiphora pyaracanthoides, displayed promising anthelmintic activity against NTS and adult S. mansoni, respectively. L. luteoalbum displayed 85.4% activity at 1 mug/mL against NTS, while C. pyracanthoides displayed 78.5% activity against adult S. mansoni at 10 mug/mL

    Informal Action—Adjudication—Rule Making: Some Recent Developments in Federal Administrative Law

    Get PDF
    Direct energy consumption of ICT hardware is only “half the story.” In order to get the “whole story,” energy consumption during the entire life cycle has to be taken into account. This chapter is a first step toward a more comprehensive picture, showing the “grey energy” (i.e., the overall energy requirements) as well as the releases (into air, water, and soil) during the entire life cycle of exemplary ICT hardware devices by applying the life cycle assessment method. The examples calculated show that a focus on direct energy consumption alone fails to take account of relevant parts of the total energy consumption of ICT hardware as well as the relevance of the production phase. As a general tendency, the production phase is more and more important the smaller (and the more energy-efficient) the devices are. When in use, a tablet computer is much more energy-efficient than a desktop computer system with its various components, so its production phase has a much greater relative importance. Accordingly, the impacts due to data transfer when using Internet services are also increasingly relevant the smaller the end-user device is, reaching up to more than 90 % of the overall impact when using a tablet computer.QC 20140825</p

    Lean beef production systems for a growing world population

    Get PDF
    Anabolic implants are used routinely in U.S. beef finishing systems with over 95% of all cattle finished for beef meat production being implanted at least once during the finishing period. Anabolic implants increase average daily gain (ADG) by 16 to 20% over the non-implanted control for anÂŹabolic implants. This translates to 0.21 to 0.26 kg/d increase in gain over non-implanted controls. Feed efficiency, reported as feed to gain, is also improved with implanting by 9 to 14% over non-implanted controls. These improveÂŹments in feed efficiency translate to a reduction in the amount of feed required per unit gain of 0.19-0.42 kg. Anabolic implants are one of the most cost efÂŹfective technologies that can be utilized in beef cattle finishing systems. Estimates are that the use of anabolic implants, on average, returns 143(USdollars)persteerdependingonbeefandgrainprices.Utilizationoftwocombinationimplantsduringthefinishingphasecanreturnupto143 (US dollars) per steer depending on beef and grain prices. Utilization of two combination implants during the finishing phase can return up to 233 per steer. The elimination of growth-promoting technologies would significantÂŹly reduce beef production and increase the number of cattle required to produce equivalent amounts of beef. This would equate to greater feedstuffs and land mass required to feed an increased number of cattle with greater methane output and reduced efficiency.Anabolic implants are used routinely in beef finishing operations in the USA, with over 95% of all cattle finished for beef production being implanted at least once during the finishing period. In grain-based systems anabolic implants increase average daily gain (ADG) by 16 to 20%, equivalent to 0.21 to 0.26 kg/d, over non-implanted controls. Feed efficiency expressed as feed/gain ratio is also improved by 9 to 14% over non-implanted controls. These improvements in feed efficiency reduce feed requirements per unit gain by 0.19 to 0.42 kg. Anabolic implants are one of the most cost-effective technologies that can be used to finish beef cattle. Estimates are that the use of this practice, on average, returns 143(USD)persteerwithvariabilitydependingonthepricesofbeefandfeedgrains.Utilizationoftwocombination(estrogenicandanabolic)implantsduringthefinishingphasecanreturnupto143 (USD) per steer with variability depending on the prices of beef and feed grains. Utilization of two combination (estrogenic and anabolic) implants during the finishing phase can return up to 233 per steer. The elimination of growth promoting technologies would significantly reduce beef production in those counties where they are used and increase the cattle inventory required to produce equivalent amounts of beef. This would equate to greater requirements of feedstuffs and land area to feed a larger number of cattle, with consequently greater methane output and reduced biological and economic efficiency

    Measurement of the conductance of a hydrogen molecule

    Get PDF
    Recent years have shown steady progress in research towards molecular electronics [1,2], where molecules have been investigated as switches [3-5], diodes [6], and electronic mixers [7]. In much of the previous work a Scanning Tunnelling Microscope was employed to address an individual molecule. As this arrangement does not provide long-term stability, more recently metal-molecule-metal links have been made using break junction devices [8-10]. However, it has been difficult to establish unambiguously that a single molecule forms the contact [11]. Here, we show that a single H2 molecule can form a stable bridge between Pt electrodes. In contrast to results for other organic molecules, the bridge has a nearly perfect conductance of one quantum unit, carried by a single channel. The H2-bridge provides a simple test system and a fundamental step towards understanding transport properties of single-molecule devices.Comment: 6 pages, 4 figure

    4MOST Consortium Survey 3: Milky Way Disc and Bulge Low-Resolution Survey (4MIDABLE-LR)

    Full text link
    The mechanisms of the formation and evolution of the Milky Way are encoded in the orbits, chemistry and ages of its stars. With the 4MOST MIlky way Disk And BuLgE Low-Resolution Survey (4MIDABLE-LR) we aim to study kinematic and chemical substructures in the Milky Way disc and bulge region with samples of unprecedented size out to larger distances and greater precision than conceivable with Gaia alone or any other ongoing or planned survey. Gaia gives us the unique opportunity for target selection based almost entirely on parallax and magnitude range, hence increasing the efficiency in sampling larger Milky Way volumes with well-defined and effective selection functions. Our main goal is to provide a detailed chrono-chemo-kinematical extended map of our Galaxy and the largest Gaia follow-up down to G=19G = 19 magnitudes (Vega). The complex nature of the disc components (for example, large target densities and highly structured extinction distribution in the Milky Way bulge and disc area), prompted us to develop a survey strategy with five main sub-surveys that are tailored to answer the still open questions about the assembly and evolution of our Galaxy, while taking full advantage of the Gaia data.Comment: Part of the 4MOST issue of The Messenger, published in preparation of 4MOST Community Workshop, see http://www.eso.org/sci/meetings/2019/4MOST.htm

    Galaxy And Mass Assembly (GAMA): the 0.013 < z < 0.1 cosmic spectral energy distribution from 0.1 m to 1 mm

    Get PDF
    We use the Galaxy And Mass Assembly survey (GAMA) I data set combined with GALEX, Sloan Digital Sky Survey (SDSS) and UKIRT Infrared Deep Sky Survey (UKIDSS) imaging to construct the low-redshift (z < 0.1) galaxy luminosity functions in FUV, NUV, ugriz and YJHK bands from within a single well-constrained volume of 3.4 × 105 (Mpc h−1)3. The derived luminosity distributions are normalized to the SDSS data release 7 (DR7) main survey to reduce the estimated cosmic variance to the 5 per cent level. The data are used to construct the cosmic spectral energy distribution (CSED) from 0.1 to 2.1 ÎŒm free from any wavelength-dependent cosmic variance for both the elliptical and non-elliptical populations. The two populations exhibit dramatically different CSEDs as expected for a predominantly old and young population, respectively. Using the Driver et al. prescription for the azimuthally averaged photon escape fraction, the non-ellipticals are corrected for the impact of dust attenuation and the combined CSED constructed. The final results show that the Universe is currently generating (1.8 ± 0.3) × 1035 h W Mpc−3 of which (1.2 ± 0.1) × 1035 h W Mpc−3 is directly released into the inter-galactic medium and (0.6 ± 0.1) × 1035 h W Mpc−3 is reprocessed and reradiated by dust in the far-IR. Using the GAMA data and our dust model we predict the mid- and far-IR emission which agrees remarkably well with available data. We therefore provide a robust description of the pre- and post-dust attenuated energy output of the nearby Universe from 0.1 ÎŒm to 0.6 mm. The largest uncertainty in this measurement lies in the mid- and far-IR bands stemming from the dust attenuation correction and its currently poorly constrained dependence on environment, stellar mass and morphology
    • 

    corecore