2,757 research outputs found

    Eight years of organic farming at Pwllpeiran – livestock production and the financial performance of organic upland

    Get PDF
    This report was presented at the UK Organic Research 2002 Conference. Established for 8 years, this project evaluates the practicalities of organic beef and sheep production on an upland farm in an ESA. Grassland productivity, stocking rates and animal performance are closely related to seasonal variations in the clover content of the small area of improved land. Improving sales have been offset by increasing input costs. Subsidy payments assist financial performance, but ESA prescriptions effectively prevent increased production

    The use of feed blocks as supplementation for the upland hill flock: (2) Cost effective lamb production

    Get PDF
    This report was presented at the UK Organic Research 2002 Conference of the Colloquium of Organic Researchers (COR).Under EU organic livestock regulations introduced in 2000, new restrictions were placed on the use of bought-in feedstuffs in hill systems. These reduced the non-organic annual percentage previously allowed in LFAs from 20% to 10% of annual dry matter intake. A further stepping down of these allowances may be introduced ahead of a complete ban in 2005. Bought-in feed supplements must therefore, be used strategically and offer “best value for money” in terms of ewe performance and lamb growth. The economic cost of supplementing the diet of twin-rearing ewes post lambing with either an approved non-organic feed block + half ration of commercial concentrate mix (B+CCM) or full ration commercial concentrate mix (CCM) was investigated. Lambs reared by ewes receiving the B+CCM diet had a greater liveweight gain than those reared by ewes receiving the CCM diet per kg of ewe supplementary feed. The costs in terms of kg lamb liveweight were lower for the B+CCM ewes than the CCM ewe

    Isotropic Oscillator Under a Magnetic and Spatially Varying Electric Field

    Get PDF
    We investigate the energy levels of a particle confined in the isotropic oscillator potential with a magnetic and spatially varying electric field. Here we are able to exactly solve the Schrodinger equation, using matrix methods, for the first excited states. To this end we find that the spatial gradient of the electric field acts as a magnetic field in certain circumstances. Here we present the changes in the energy levels as functions of the electric field, and other parameters

    The Effect of Particle Strength on the Ballistic Resistance of Shear Thickening Fluids

    Full text link
    The response of shear thickening fluids (STFs) under ballistic impact has received considerable attention due to its field-responsive nature. While efforts have primarily focused on the response of traditional ballistic fabrics impregnated with fluids, the response of pure STFs to penetration has received limited attention. In the present study, the ballistic response of pure STFs is investigated and the effect of fluid density and particle strength on ballistic performance is isolated. The loss of ballistic resistance of STFs at higher impact velocities is governed by particle strength, indicating the range of velocities over which they may provide effective armor solutions.Comment: 4 pages, 4 figure

    Othello and the Democrats

    Get PDF
    Bad criticism is often the result of imposing on a work an unhelpful theoretical model: in the case of Othello, a tragic model developed by nineteenth-century critics out of Aristotle's Poetics. We are accustomed to look for a tragic hero with a fatal flaw, with hubris or with hamartia (in the non-Aristotelian sense of moral fault) that leads to catastrophe. Criticism of Shakespeare's Othello is still very much engaged in a long war over the personality and progress of the tragic hero. There are two conflicting schools, each of which offers an interpretation that is faithful to details but unsatisfactory as a final account; and if individuals have withdrawn from the contest, it was more because discussion had grown tedious than because it had reached solutions. A. C. Bradley might be taken as one extreme, giving us the noble Moor, virtuous, open and majestic, a "rough diamond" whose only conceivable flaw might be that his generous nature prompted him to over-impulsive action. The problem with such a reading of the character, as Harley Granville-Barker found, is that Othello's end must seem meaningless and non-uplifting. At the other extreme, we have T. S. Eliot and, after him, F. R. Leavis offering us an unheroic Moor, a self-dramatizer and unconscious poseur, a life denying romantic who retreats at the last into protective self deception and avoidance of reality

    Fragmentation of a molten metal droplet in an ambient water flow

    Get PDF
    The influence of an ambient fluid flow on the fragmentation of hot molten tin droplets (initially at 800°C) and cold low melting point alloy droplets (initially at 70°C) in water is investigated with high-speed photography and flash radiography. The water is accelerated using a converging nozzle to a constant speed of up to 30 m/s using a double piston arrangement designed to eliminate the formation of a shock wave that is present in most earlier studies. At low flow velocities, the fragmentation of hot droplets is governed by thermal effects and vapour formation, growth, and collapse. At high flow velocities, vapour formation is suppressed and the droplet fragmentation is determined by hydrodynamic effects in which hydrodynamic instabilities (Rayleigh-Taylor and Kelvin-Helmholtz) and wavecrest stripping all play a role in the droplet breakup. At intermediate flow velocities, both thermal and hydrodynamic effects play a role. Quantitative image analysis of the radiographs is used to determine the spatial distribution of the droplet mass during the fragmentation process. Comparison with earlier work in which the ambient flow is preceded by a strong shock wave indicates that the transition from thermal to hydrodynamic breakup is strongly dependent on the pressure field

    Scan time reduction for readout-segmented EPI using simultaneous multislice acceleration: Diffusion-weighted imaging at 3 and 7 Tesla

    Get PDF
    Purpose: Readout‐segmented echo‐planar imaging (rs‐EPI) can provide high quality diffusion data because it is less prone to distortion and blurring artifacts than single‐shot echo‐planar imaging (ss‐EPI), particularly at higher resolution and higher field. Readout segmentation allows shorter echo‐spacing and echo train duration, resulting in reduced image distortion and blurring, respectively, in the phase‐encoding direction. However, these benefits come at the expense of longer scan times because the segments are acquired in multiple repetitions times (TRs). This study shortened rs‐EPI scan times by reducing the TR duration with simultaneous multislice acceleration. Methods: The blipped‐CAIPI method for slice acceleration with reduced g‐factor SNR loss was incorporated into the diffusion‐weighted rs‐EPI sequence. The rs‐ and ss‐EPI sequences were compared at a range of resolutions at both 3 and 7 Tesla in terms of image fidelity and diffusion postprocessing results. Results: Slice‐accelerated clinically useful trace‐weighted images and tractography results are presented. Tractography analysis showed that the reduced artifacts in rs‐EPI allowed better discrimination of tracts than ss‐EPI. Conclusion: Slice acceleration reduces rs‐EPI scan times providing a practical alternative to diffusion‐weighted ss‐EPI with reduced distortion and high resolution. Magn Reson Med 74:136–149, 2015

    Role of peripheral quantitative computed tomography in identifying disuse osteoporosis in paraplegia

    Get PDF
    Objective: Disuse osteoporosis is a major long-term health consequence of spinal cord injury (SCI) that still needs to be addressed. Its management in SCI should begin with accurate diagnosis, followed by targeted treatments in the most vulnerable subgroups. We present data quantifying disuse osteoporosis in a cross-section of the Scottish paraplegic population to identify subgroups with lowest bone mineral density (BMD). Materials and Methods: Forty-seven people with chronic SCI at levels T2-L2 were scanned using peripheral Quantitative Computed Tomography (pQCT) at four tibial sites and two femoral sites, at the Queen Elizabeth National Spinal Injuries Unit, Glasgow (U.K.). At the distal epiphyses, trabecular BMD (BMDtrab), total BMD, total bone cross-sectional area (CSA), and bone mineral content (BMC) were determined. In the diaphyses, cortical BMD, total bone CSA, cortical CSA, and BMC were calculated. Bone, muscle and fat CSAs were estimated in the lower leg and thigh. Results: BMDtrab decreased exponentially with time since injury, at different rates in the tibia and femur. At most sites, female paraplegics had significantly lower BMC, total bone CSA and muscle CSA than male paraplegics. Subjects with lumbar SCI tended to have lower bone values and smaller muscle CSAs than in thoracic SCI. Conclusion: At the distal epiphyses of the tibia and femur, there is generally a rapid and extensive reduction in BMDtrab after SCI. Female subjects, and those with lumbar SCI, tend to have lower bone values than males or those with thoracic SCI, respectively. Keywords: Bone loss, osteoporosis, paraplegia, peripheral Quantitative Computed Tomography, spinal cord injur
    • 

    corecore