1,049 research outputs found

    Black hole solutions to the F4F_4-model and their orbits (I)

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    In this paper we continue the program of the classification of nilpotent orbits using the approach developed in arXiv:1107.5986, within the study of black hole solutions in D=4 supergravities. Our goal in this work is to classify static, single center black hole solutions to a specific N=2 four dimensional "magic" model, with special K\"ahler scalar manifold Sp(6,R)/U(3){\rm Sp}(6,\mathbb{R})/{\rm U}(3), as orbits of geodesics on the pseudo-quaternionic manifold F4(4)/[SL(2,R)×Sp(6,R)]{\rm F}_{4(4)}/[{\rm SL}(2,\mathbb{R})\times {\rm Sp}(6,\mathbb{R})] with respect to the action of the isometry group F4(4){\rm F}_{4(4)}. Our analysis amounts to the classification of the orbits of the geodesic "velocity" vector with respect to the isotropy group H=SL(2,R)×Sp(6,R)H^*={\rm SL}(2,\mathbb{R})\times {\rm Sp}(6,\mathbb{R}), which include a thorough classification of the \emph{nilpotent orbits} associated with extremal solutions and reveals a richer structure than the one predicted by the βγ\beta-\gamma labels alone, based on the Kostant Sekiguchi approach. We provide a general proof of the conjecture made in arXiv:0908.1742 which states that regular single center solutions belong to orbits with coinciding βγ\beta-\gamma labels. We also prove that the reverse is not true by finding distinct orbits with the same βγ\beta-\gamma labels, which are distinguished by suitably devised tensor classifiers. Only one of these is generated by regular solutions. Since regular static solutions only occur with nilpotent degree not exceeding 3, we only discuss representatives of these orbits in terms of black hole solutions. We prove that these representatives can be found in the form of a purely dilatonic four-charge solution (the generating solution in D=3) and this allows us to identify the orbit corresponding to the regular four-dimensional metrics.Comment: 81 pages, 24 tables, new section 4.4 about the fake superpotential added, typos corrected, references added, accepted in Nuclear Physics B.

    Use of weaning concentrate in the feeding suckling kids: effects on meat quality

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    The effect of a feeding supplementation with starter concentrate on “Capretto” meat production and its qualitative characteristics was investigated. The results showed that the effect of concentrate supplementation did not influence the slaughter weight, slaughter and dissection data, tissue composition and meat chemical composition of the pelvic limb. No differences were found for rheological characteristics of LD meat, except cohesiveness values, which were higher in the concentrate group kids

    Uncertainty quantification in energy management procedures

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    Complex energy systems are made up of a number of components interacting together via different energy vectors. The assessment of their performance under dynamic working conditions, where user demand and energy prices vary over time, requires a simulation tool. Regardless of the accuracy of this procedure, the uncertainty in data, obtained both by measurements or by forecasting, is usually non-negligible and requires the study of the sensitivity of results versus input data. In this work, polynomial chaos expansion technique is used to evaluate the variation of cogeneration plant performance with respect to the uncertainty of energy prices and user requests. The procedure allows to obtain this information with a much lower computational cost than that of usual Monte-Carlo approaches. Furthermore, all the tools used in this paper, which were developed in Python, are published as free and open source software

    The influence of somatic cell count on sheep milk composition and cheese-making properties

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    Somatic cell count (SCC) is an important tool for monitoring intramammary infections in dairy cows. However, systematic generalization of this decision rule is not easy in small ruminants. Determination of SCC in sheep milk is important for the processors of milk (indicator of quality), for breeders (mastitis indicator) and could be useful for selection as well. SCC value can be affected by some non-infective factors such as breed, stage of lactation, parity, type of lambing, type of milking, etc. (Bergonier et al., 1994), as well the health status of the udder (Fruganti et al., 1985; Ranucci et al., 1988). In addition, EC Directive 92/46, which regulates the production and commercialisation of milk and dairy products, imposes strict limits on SCC from dairy cattle but it does not dispel the uncertainty over recommended SCC levels in small ruminants.With the aim of knowing more about somatic cells count and their effects on milk quality and cheese-making properties an experimental trial was carried out

    factors associated with milk urea concentrations in girgentana goats

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    A total of 1,481 milk samples of 166 Girgentana goats, taken along the entire lactation, were utilised to evaluate the effect of non nutritional factors on milk urea (MU). Parity, stage of lactation and month of sampling significantly influenced MU, while no effect was found for born kids number. The first kidding goats produced lower MU than multiparous goats. Trend of MU was similar to milk production course with a peak found at 60 DIM. The different MU levels between several months of production are often linked to pasture chemical variations

    Mobility-Aware Edge Caching for Connected Cars

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    Content caching on the edge of 5G networks is an emerging and critical feature to support the thirst for content of future connected cars. Yet, the compactization of 5G cells, the finite edge storage capacity and the need for content availability while driving motivate the need to develop smart edge caching strategies adapted to the mobility characteristics of connected cars. In this paper, we propose a Mobility-Aware Probabilistic (MAP) scheme, which optimally caches content at edge nodes where connected vehicles mostly require it. Unlike blind popularity decisions, the probabilistic caching used by MAP considers vehicular trajectory predictions as well as content service time by edge nodes. We evaluate our approach on realistic mobility datasets and against popularity-based edge approaches. Our MAP edge caching scheme provides up to 40% enhanced content availability, 70% increased cache throughput, and 40% reduced backhaul overhead compared to popularity-based strategies

    Phenotypic and genetic analysis of udder health using SCC in Valle del Belice dairy sheep

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    Intramammary infections (IMI) are a complex of inflammatory diseases which are defined as an inflammation of the mammary gland resulting from the introduction and multiplication of pathogenic micro-organisms
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