8,203 research outputs found

    Electroweak Tests at Beta-beams

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    We explore the possibility of measuring the Weinberg angle from (anti)neutrino-electron scattering using low energy beta beams, a method that produces single flavour neutrino beams from the beta-decay of boosted radioactive ions. We study how the sensitivity of a possible measurement depends on the intensity of the ion beam and on a combination of different Lorentz boosts of the ions.Comment: 10 pages, 6 figure

    Dark matter cores in the Fornax and Sculptor dwarf galaxies: joining halo assembly and detailed star formation histories

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    We combine the detailed Star Formation Histories of the Fornax and Sculptor dwarf Spheroidals with the Mass Assembly History of their dark matter (DM) halo progenitors to estimate if the energy deposited by Supernova type II (SNeII) is sufficient to create a substantial DM core. Assuming the efficiency of energy injection of the SNeII into DM particles is ϵgc=0.05\epsilon_{\rm gc}=0.05, we find that a single early episode, zzinfallz \gtrsim z_{\rm infall}, that combines the energy of all SNeII due to explode over 0.5 Gyr, is sufficient to create a core of several hundred parsecs in both Sculptor and Fornax. Therefore, our results suggest that it is energetically plausible to form cores in Cold Dark Matter (CDM) halos via early episodic gas outflows triggered by SNeII. Furthermore, based on CDM merger rates and phase-space density considerations, we argue that the probability of a subsequent complete regeneration of the cusp is small for a substantial fraction of dwarf-size haloes.Comment: ApJL accepted versio

    Influence of the external pressure on the quantum correlations of molecular magnets

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    The study of quantum correlations in solid state systems is a large avenue for research and their detection and manipulation are an actual challenge to overcome. In this context, we show by using first-principles calculations on the prototype material KNaCuSi4_{4}O10_{10} that the degree of quantum correlations in this spin cluster system can be managed by external hydrostatic pressure. Our results open the doors for research in detection and manipulation of quantum correlations in magnetic systems with promising applications in quantum information science

    Caracterização de acessos silvestres de maracujazeiro com base em descritores morfoagronômicos.

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    Existem espécies silvestres de maracujazeiros que possuem potencial agronômico para a utilização no melhoramento genético e no desenvolvimento de variedades e híbridos, porém a escassez de informações morfoagronômicas dessas espécies silvestres indica a necessidade de estudos básicos relacionados à caracterização e à avaliação do germoplasma. Este trabalho teve como objetivo caracterizar acessos silvestres de maracujazeiro, com base em descritores qualitativos e quantitativos

    Correlação entre heterose e divergência genética em genótipos de maracujá amarelo.

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    Este trabalho avaliou a heterose de híbridos de maracujá amarelo, obtidos por cruzamentos dialélicos entre genótipos divergentes e a sua correlação com a distância genética obtida por meio de marcadores ISSR (Inter Simple Sequence Repeats). Os trinta híbridos resultantes do dialelo parcial apresentaram diferenças significativas para as variáveis: número de frutos (NF), peso do fruto (PF), produtividade (PROD), rendimento (REND) e sólidos solúveis totais (SST). Apenas a variável número de frutos apresentou efeitos aditivos no controle genético. Não foi observada correlação significativa pela estatística de Mantel entre distância genética vs heterose, capacidade específica de combinação e a média para as características analisadas, o que não permite predizer o comportamento dos híbridos de maracujazeiro

    A Conserved Vector Current test using low energy beta-beams

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    We discuss the possibility of testing the weak currents and, in particular, the weak magnetism term through the measurement of the electron anti-neutrinos capture by protons at a low energy beta-beam facility. We analyze the sensitivity using both the total number of events and the angular distribution of the positrons emitted in a water Cerenkov detector. We show that the weak magnetism form factor might be determined with better than several percent accuracy using the angular distribution. This offers a new way of testing the Conserved Vector Current hypothesis.Comment: 8 pages, 5 figure

    Inseticidas e intervalos de pulverizacao para o controle lagarta rosada (Pectinophora gossypiela (Saund) (Lepidoptera, gelechiidae) no algodoeiro herbaceo.

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    Ultra-low-cycle fatigue of pipeline steels

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    PING 2019 is organized with the support of funds for specific university research project SVK1-2019-002.Pipelines and piping components when subjected to extreme loading conditions (e.g. earthquakes, hurricanes, support settlements, industrial plant shutdown) undergo large plastic deformations, associated with widespread yielding, leading to fracture, either due to monotonic loading or ultra-low-cycle fatigue (ULCF). ULCF is neither satisfactorily understood nor conveniently investigated compared to the monotonic ductile or low-cycle fatigue damage mechanisms. Having in mind the existing gaps in the knowledge about the ULCF, the ULCF European project, coordinated by FEUP, aimed at developing innovative computational methodologies for the simulation of steel material fracture under both monotonic and ultra-low-cycle fatigue, based on a significant experimental program including small and large-scale tests. This presentation makes an overview of the main results of the project, which includes: i) Database of small-scale testing data covering the X52, X60, X65, X70 and X80 piping steel grades. Smooth and special notched specimens were tested under both monotonic and cyclic (LCF & ULCF) loading. Dedicated monotonic tests were performed to assess the anisotropic behaviour of some materials (X70/X80). Combined multiaxial loading conditions were also investigated. ii) Database of full-scale testing results covering same materials also tested under small-scale conditions was generated. Monotonic and ULCF tests of pipe components were performed. ULCF tests included buckled and dented pipes, elbows and straight pipes. iii) New constitutive models for both monotonic and ULCF loading were proposed. Besides the Barcelona model, alternative approaches were investigated. Further constitutive refinements of nonlinear monotonic damage and enhanced anisotropic models, were also studied. iv) Developed constitutive models were calibrated and validated using experimentally derived testing data
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