3,480 research outputs found

    Fission-fragment mass distributions from strongly damped shape evolution

    Full text link
    Random walks on five-dimensional potential-energy surfaces were recently found to yield fission-fragment mass distributions that are in remarkable agreement with experimental data. Within the framework of the Smoluchowski equation of motion, which is appropriate for highly dissipative evolutions, we discuss the physical justification for that treatment and investigate the sensitivity of the resulting mass yields to a variety of model ingredients, including in particular the dimensionality and discretization of the shape space and the structure of the dissipation tensor. The mass yields are found to be relatively robust, suggesting that the simple random walk presents a useful calculational tool. Quantitatively refined results can be obtained by including physically plausible forms of the dissipation, which amounts to simulating the Brownian shape motion in an anisotropic medium.Comment: 14 pages, 11 ps figure

    Modeling and Analysis Generic Interface for eXternal numerical codes (MAGIX)

    Full text link
    The modeling and analysis generic interface for external numerical codes (MAGIX) is a model optimizer developed under the framework of the coherent set of astrophysical tools for spectroscopy (CATS) project. The MAGIX package provides a framework of an easy interface between existing codes and an iterating engine that attempts to minimize deviations of the model results from available observational data, constraining the values of the model parameters and providing corresponding error estimates. Many models (and, in principle, not only astrophysical models) can be plugged into MAGIX to explore their parameter space and find the set of parameter values that best fits observational/experimental data. MAGIX complies with the data structures and reduction tools of ALMA (Atacama Large Millimeter Array), but can be used with other astronomical and with non-astronomical data.Comment: 12 pages, 15 figures, 2 tables, paper is also available at http://www.aanda.org/articles/aa/pdf/forth/aa20063-12.pd

    Constraining the Λ\LambdaCDM and Galileon models with recent cosmological data

    Get PDF
    The Galileon theory belongs to the class of modified gravity models that can explain the late-time accelerated expansion of the Universe. In previous works, cosmological constraints on the Galileon model were derived, both in the uncoupled case and with a disformal coupling of the Galileon field to matter. There, we showed that these models agree with the most recent cosmological data. In this work, we used updated cosmological data sets to derive new constraints on Galileon models, including the case of a constant conformal Galileon coupling to matter. We also explored the tracker solution of the uncoupled Galileon model. After updating our data sets, especially with the latest \textit{Planck} data and BAO measurements, we fitted the cosmological parameters of the Λ\LambdaCDM and Galileon models. The same analysis framework as in our previous papers was used to derive cosmological constraints, using precise measurements of cosmological distances and of the cosmic structure growth rate. We showed that all tested Galileon models are as compatible with cosmological data as the Λ\LambdaCDM model. This means that present cosmological data are not accurate enough to distinguish clearly between both theories. Among the different Galileon models, we found that a conformal coupling is not favoured, contrary to the disformal coupling which is preferred at the 2.3σ2.3\sigma level over the uncoupled case. The tracker solution of the uncoupled Galileon model is also highly disfavoured due to large tensions with supernovae and \textit{Planck}+BAO data. However, outside of the tracker solution, the general uncoupled Galileon model, as well as the general disformally coupled Galileon model, remain the most promising Galileon scenarios to confront with future cosmological data. Finally, we also discuss constraints coming from Lunar Laser Ranging experiment and gravitational wave speed of propagation.Comment: 22 pages, 17 figures, published version in A&

    Wirtschaftlichkeit weidebasierter Öko-Milchviehhaltung: Erste Ergebnisse zu Wirkungszusammenhängen mit ausgewählten Tiergesundheits-Parametern

    Get PDF
    In this analysis correlations between economic data of pasture-based organic dairy livestock and production-related indicators like milk yield, use of concentrated feed and animal health parameters were calculated. The result shows positive relations between the economics and some of the production-related indicators, but not with the grazing intensity. There are positive correlations between animal health parameters and both milk yield and economic data. Hence an economically oriented animal health optimization strategy could improve economic success

    BLOOD BIOCHEMICAL PROFILE IN DOGS AND CATS UNDER DIFFERENT FEEDING DIETS

    Get PDF
    Foram determinados os parâmetros de bioquímica sanguínea em 50 cães e 25 gatos sadios submetidos a três regimes alimentares: ração comercial, comida caseira e alimentação mista (ração e caseira). Os cães e os gatos alimentados com regime misto apresentaram níveis sanguíneos elevados de glicose e de colesterol, sugerindo um consumo de alimentos calóricos acima dos requerimentos e um maior risco de obesidade. A ingestão de proteínas na alimentação caseira parece ser restrita, considerando-se as baixas concentrações de albumina e/ou uréia sanguíneas nos cães e nos gatos. Baixos teores de cálcio foram encontrados nos cães de alimentação não concentrada. Os gatos com alimentação caseira podem estar consumindo quantidades baixas de minerais revelado pelos menores teores sanguíneos de cálcio, fósforo e magnésio. Abstract The aim of the present work was to carry out a study on the variation of the blood chemistry constituents of dogs and cats subjected to different feeding diets. Blood samples from 50 healthy dogs and 25 cats were used to study the effect of feeding diets with commercial ration, homemade or mixed (concentrate and homemade) on their blood biochemical profile. Both, dogs and cats, fed with mixed rations showed higher glucose and cholesterol blood levels, which could be suggestive of a high caloric intake and a risk of obesity. Intake of proteins in animals with homemade feed seems to be low considering concentrations of plasma albumin and/or urea in dogs and cats. Low levels of calcium were found in dogs with non-concentrated feed. Cats with homemade feed could have low intake of minerals considering the lower levels of calcium, phosphorus and magnesium observed
    corecore