9,223 research outputs found

    Performance and intestinal responses to dehulling and inclusion level of Australian sweet lupins (Lupinus angustifolius L.) in diets for weaner pigs

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    A total of 180 entire male weaner pigs weighing 6.4 ± 0.1. kg (mean ± SEM) and housed in pairs was used in a completely randomised block design with 9 dietary treatments (n= 10 pens). Pigs were blocked based on weaning weight. The diets were (i) a wheat-based control diet containing 240. g/kg of milk products (whey and skim milk powder), and (ii) 8 diets containing whole or dehulled lupins (cv. Coromup) that substituted the milk products at 60, 120, 180 and 240. g/kg of diet (replace 25%, 50%, 75%, or 100% of the milk products in the control diets). The diets were isoenergetic [15. MJ digestible energy (DE)/kg], and were formulated to contain the same ileal standardised digestible lysine content (0.85. g/MJ DE) and ideal patterns of other essential amino acids. Pigs receiving 240. g/kg of dehulled lupins grew slower (P<0.05) than pigs fed the other diets mainly due to decreased feed intake. Pigs fed diets containing more than 180. g/kg of dehulled lupins had a higher faecal β-haemolytic Escherichia coli score on day 3 after weaning (P<0.05). Moreover, inclusion of 240. g/kg of whole lupin or more than 180. g/kg of dehulled lupins increased (P<0.001) plasma urea nitrogen (PUN) levels. Total tract apparent digestibility (TTAD) of dry matter decreased (P<0.001) in all lupin diets compared with the control diet. These data indicate that inclusion of dehulled lupin immediately after weaning should be limited to less than 180. g/kg whilst whole lupins can be included up to 240. g/kg without deleterious effects on production and intestinal health

    Delivering building simulation information via new communication media

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    Often, the goal of understanding how the building works and the impact of design decisions is hampered by limitations in the presentation of performance data. Contemporary results display is often constrained to what was considered good practice some decades ago rather than in ways that preserve the richness of the underlying data. This paper reviews a framework for building simulation support that addresses these presentation limitations as well as making a start on issues related to distributed team working. The framework uses tools and communication protocols that enable concurrent information sharing and provide a richer set of options for understanding complex performance relationships

    Efficacy of a reduced protein diet on clinical expression of post-weaning diarrhoea and life-time performance after experimental challenge with an enterotoxigenic strain of Escherichia coli

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    Previous experiments have shown that feeding a reduced protein diet within the first 2 weeks post-weaning reduces gastrointestinal protein fermentation and clinical expression of post-weaning diarrhoea (PWD). However, growth of young pigs receiving a reduced protein diet without crystalline essential amino acids (CEAA) supplementation is depressed after weaning. It has been argued that the short-term performance reduction caused by feeding a reduced protein diet would be compensated and the lifetime performance of pigs would not be affected. An experiment was therefore conducted to examine PWD and lifetime growth of pigs after feeding a reduced protein diet without and with CEAA supplementation for 2 weeks after weaning. Two hundred individually housed pigs weaned at 21 d of age (Large White×Landrace, castrate:female ratio of 1:1, mean±SEM body weight of 5.5±0.05kg) were stratified to one of four dietary treatments (n=50): High protein+antimicrobial compound diet (HP+AMC, 230g crude protein (CP) with 2.5g lincospectin and 3g zinc oxide per kg feed), High protein diet (HP, 230gCP/kg), Reduced protein+amino acid supplemented diet (RP+AA, 185gCP/kg with added CEAA up to HP level), and Reduced protein diet (RP, 185g CP/kg without CEAA supplementation). Pigs were fed the experimental diet for 2 weeks and then all pigs were fed the same series of commercial diets until slaughter. All pigs were experimentally infected with an enterotoxigenic strain of E. coli (6 and 10mL of 1.9×109cfu/mL, serotype O149:K91:K88) at 72, and 96h after weaning. Infection increased plasma haptoglobin levels (P0.05). Carcass characteristics were not affected (P>0.05) by the treatments. The results indicate that although feeding a RP diet without CEAA supplementation decreased performance after weaning, it did not influence lifetime performance or carcass characteristics and reduced the clinical expression of PWD

    Energy, carbon and cost performance of building stocks : upgrade analysis, energy labelling and national policy development

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    The area of policy formulation for the energy and carbon performance of buildings is coming under increasing focus. A major challenge is to account for the large variation within building stocks relative to factors such as location, climate, age, construction, previous upgrades, appliance usage, and type of heating/cooling/lighting system. Existing policy-related tools that rely on simple calculation methods have limited ability to represent the dynamic interconnectedness of technology options and the impact of possible future changes in climate and occupant behaviour. The use of detailed simulation tools to address these limitations in the context of policy development has hitherto been focussed on the modelling of a number of representative designs rather than dealing with the spread inherent in large building stocks. Further, these tools have been research-oriented and largely unsuitable for direct use by policy-makers, practitioners and, ultimately, building owners/occupiers. This paper summarises recent initiatives that have applied advanced modelling and simulation in the context of policy formulation for large building stocks. To exemplify the stages of the process, aspects of the ESRU Domestic Energy Model (EDEM) are described. EDEM is a policy support tool built on detailed simulation models aligned with the outcomes of national surveys and future projections for the housing stock. On the basis of pragmatic inputs, the tool is able to determine energy use, carbon emissions and upgrade/running cost for any national building stock or sub-set. The tool has been used at the behest of the Scottish Building Standards Agency and South Ayrshire Council to determine the impact of housing upgrades, including the deployment of new and renewable energy systems, and to rate the energy/carbon performance of individual dwellings as required by the European Commission's Directive on the Energy Performance of Buildings (EC 2002)

    Performance of RF MEMS switches at low temperatures

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    The actuation voltage of microelectromechanical system (MEMS) \ud metal switches was investigated at temperatures ranging from 10 to 290 K. The investigation shows a 50% increase in the actuation voltage at low temperature. A comparison has been made using a published model and showed similar increment of actuation voltage at low temperature

    Spectroscopic characterization of 1.3µm GaInNAs quantum-well structures grown by metal-organic vapor phase epitaxy

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    We report optical studies of high-quality 1.3 μm strain-compensated GaInNAs/GaAs single-quantum-well structures grown by metalorganic vapor phase epitaxy. Photoluminescence excitation (PLE) spectroscopy shows clearly the electronic structure of the two-dimensional quantum well. The transition energies between quantized states of the electrons and holes are in agreement with theoretical calculations based on the band anti-crossing model in which the localized N states interact with the extended states in the conduction band. We also investigated the polarization properties of the luminescence by polarized edge-emission measurements. Luminescence bands with different polarization characters arising from the electron to heavy-hole and light-hole transitions, respectively, have been identified and verify the transition assignment observed in the PLE spectrum

    Aeroacoustic source mechanisms of a wavy leading edge undergoing vortical disturbances

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    High-accuracy numerical simulations are performed to study aeroacoustic source mechanisms of wavy leading edges (WLEs) on a thin aerofoil undergoing vortical disturbances. This canonical study is based on a prescribed spanwise vortex travelling downstream and creating secondary vortices as it passes through the aerofoil’s leading edge. The primary aim of the study is to precisely understand the relationships between the vortex-induced velocity perturbation and the wall pressure fluctuation on the WLE geometry. It is observed that by increasing the size (amplitude) of the WLE the source strength at the peak region is reduced rapidly to a certain point, followed by a saturation stage, while at the root (trough) it remains fairly consistent regardless of the WLE size. This observation is demonstrated to be the consequence of three-dimensional vortex dynamics taking place along the WLE. One of the most profound features is that a system of horseshoe-like secondary vortices are created from the WLE peak region upon the impingement of the prescribed vortex. It is found that the horseshoe vortices produce a significantly non-uniform velocity perturbation in front of the WLE leading to the disparity in the source characteristics between the peak and root. The alterations to the impinging velocity perturbation are carefully analysed and related to the wall pressure fluctuation in this study. In addition, a semi-analytic model based on Biot–Savart’s law is developed to better understand and explain the role of the horseshoe vortex systems and the source mechanisms

    Mesons and nucleons from holographic QCD in a unified approach

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    We investigate masses and coupling constants of mesons and nucleons within a hard wall model of holographic QCD in a unified approach. We first examine an appropriate form of fermionic solutions by restricting the mass coupling for the five dimensional bulk fermions and bosons. We then derive approximated analytic solutions for the nucleons and the corresponding masses in a small mass coupling region. In order to treat meson and nucleon properties on the same footing, we introduce the same infrared (IR) cut in such a way that the meson-nucleon coupling constants, i.e., g_{pi NN} and g_{rho NN} are uniquely determined. The first order approximation with respect to a dimensionless expansion parameter, which is valid in the small mass coupling region, explicitly shows difficulties to avoid the IR scale problem of the hard wall model. We discuss possible ways of circumventing these problems.Comment: 15 pages, No figure. Several typos have been remove

    Screening of Irish Fruit and Vegetable Germplasm for Novel Anti-tumour and Pesticidal Compounds

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    Conference paperPhytochemicals are a rich source of novel therapeutic and insecticidal agents (McLaughlin and Chang, 1999). Considerable research effort has been directed at screening exotic and medicinal plants in the search for novel products. However, plants which have traditional food uses have been little explored. In addition the range, type and level of individual bioactive compounds can vary significantly between different species, different cultivars of the same species and different tissue types of the plant (Reilly, in press) Therefore, the objective of this study was to screen a range of fruits and vegetables which can be grown in Ireland for novel bioactive compounds for use in food production and as bio-pesticides.The author wishes to acknowledge the financial support from the Dublin Institute of Technology through an ABBEST fellowshi

    Density profiles of a colloidal liquid at a wall under shear flow

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    Using a dynamical density functional theory we analyze the density profile of a colloidal liquid near a wall under shear flow. Due to the symmetries of the system considered, the naive application of dynamical density functional theory does not lead to a shear induced modification of the equilibrium density profile, which would be expected on physical grounds. By introducing a physically motivated dynamic mean field correction we incorporate the missing shear induced interparticle forces into the theory. We find that the shear flow tends to enhance the oscillations in the density profile of hard-spheres at a hard-wall and, at sufficiently high shear rates, induces a nonequilibrium transition to a steady state characterized by planes of particles parallel to the wall. Under gravity, we find that the center-of-mass of the density distribution increases with shear rate, i.e., shear increases the potential energy of the particles
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