30,695 research outputs found

    Interpolation and scattered data fitting on manifolds using projected Powell–Sabin splines

    Get PDF
    We present methods for either interpolating data or for fitting scattered data on a two-dimensional smooth manifold. The methods are based on a local bivariate Powell-Sabin interpolation scheme, and make use of a family of charts {(Uξ , ξ)}ξ∈ satisfying certain conditions of smooth dependence on ξ. If is a C2-manifold embedded into R3, then projections into tangent planes can be employed. The data fitting method is a two-stage method. We prove that the resulting function on the manifold is continuously differentiable, and establish error bounds for both methods for the case when the data are generated by a smooth function

    Feeding with chicory roots reduces the amount of odorous compounds in colon and rectal contents of pigs

    Get PDF
    Sixteen pigs (eight entire males and eight females) were given individually two diets, control and control added 25% chopped chicory roots for 2 months before slaughter. Samples were taken from the contents in colon and rectum and subjected to GC-MS analysis for amount of odour impact compounds. The compounds 2-pentanone, ethylbutyrate, propylpropionate, butyric acid, ethyl-2-methylbutyrate, p-cresol, indole and skatole showed a significant difference between the two treatments. The esters, which have relatively pleasant, often fruity odours, increased in the chicory treatment, whereas the malodorous compounds, p-cresol, indole and skatole decreased in the chicory treatment. The measured amounts of compounds were corrected for their odour thresholds as different compounds can have widely different odour thresholds. Principal components analysis was then used to analyse the raw and corrected data results. p-Cresol was the most malodorous compound and together with skatole and indole count as the most malodorous compounds in the colon and rectum cotents. However, butyric acid also had some minor influence. Feeding chicory roots decreased significantly the concentrations of these malodorous compounds, especially if the lowest odour threshold values are used as correction factors

    Towards a process simulation tool for the laseer assisted tape placement process

    Get PDF
    A combined optical and thermal model for the laser assisted tape placement process is presented. The optical model adopts a ray tracing procedure, based on the Fresnel equations, to predict the incident heat flux on the tape and substrate near the nip-point. The heat flux distribution is subsequently used in a one-dimensional thermal model to predict the temperature distribution in the tape and substrate. The results demonstrate that for small incident laser angles a part of the laser light is reflected at the surface, which significantly influences the temperature distribution in the nip-point. The presented model allows, with a weld strength and consolidation model, optimization of the processing parameters

    Perceptual simulation in conceptual tasks

    Get PDF
    No abstract available

    Color Transparency Effects in Electron Deuteron Interactions at Intermediate Q^2

    Full text link
    High momentum transfer electrodisintegration of polarized and unpolarized deuterium targets, d(e,ep)nd(e,e'p)n is studied. We show that the importance of final state interactions-FSI, occuring when a knocked out nucleon interacts with the other nucleon, depends strongly on the momentum of the spectator nucleon. In particular, these FSI occur when the essential contributions to the scattering amplitude arise from internucleon distances 1.5 fm\sim 1.5~fm. But the absorption of the high momentum γ\gamma^* may produce a point like configuration, which evolves with time. In this case, the final state interactions probe the point like configuration at the early stage of its evolution. The result is that significant color transparency effects, which can either enhance or suppress computed cross sections, are predicted to occur for 4GeV2Q2 10 (GeV/c)2\sim 4 GeV^2 \ge Q^2\leq~10~(GeV/c)^2.Comment: 37 pages LaTex, 12 uuencoded PostScript Figures as separate file, to be published in Z.Phys.

    HIV and orientation of subsistence and commercial home gardens in rural Ghana: Crop composition, crop diversity and food security

    Get PDF
    An empirical study was conducted to explore differences and similarities in biodiversity in subsistence and commercial home gardens of HIV-positive and HIV-negative rural households in the Eastern Region of Ghana and their significance in household food security. Data were obtained through a household and home garden survey of a purposive sample of 32 HIV-positive and a random sample of 48 HIV-negative rural households and through in-depth interviews. A higher proportion of species common to all four home garden types consisted of food crops: vegetables, staples and fruits. In HIV-positive households, commercial home gardens were significantly larger, had significantly more species and individual plants, more perennial food crops and more species that were harvested all year round and evenness was lower, but there was no significant difference in species diversity compared with subsistence home gardens. Significantly, more HIV-positive and HIV-negative households with a commercial home garden consumed a staple crop cultivated in the home garden in the 24-h period prior to the survey than HIV-positive households with subsistence home gardens. Rural households with HIV that manage commercial home gardens cultivate a dual purpose home garden which supplies subsistence food and also provides cash income; such households may have better food security than households that cultivate subsistence home garden

    Reducing the risk of food borne pathogens (Campylobacter) in pre-slaughter pigs via short-time feeding with prebiotics

    Get PDF
    Reducing the presence of human pathogens like Campylobacter and Salmonella (zoonoses) in their animal hosts is important to enhance food safety of products of animal origin. Campylobacter is considered to be a commensal in the gastrointestinal tract of pigs due to its typically high prevalence. Consequently, it is difficult to control Campylobacter in pigs at farm level by usual hygienic measures, especially in open systems of organic pig production (Jensen et al 2006). However, another potential means to control pathogens is inclusion of non-digestible oligosaccharides (prebiotics) in the diet. For example, prebiotics proofed successful in control of the intestinal disease swine dysentery caused by the spirochaete Brachyspira hyodysenteriae (Molbak et al. 2007
    corecore