8,668 research outputs found

    The Discovery of an X-ray/UV Stellar Flare from the Late-K/Early-M Dwarf LMC 335

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    We report the discovery of an X-ray/UV stellar flare from the source LMC 335, captured by XMM-Newton in the field of the Large Magellanic Cloud. The flare event was recorded continuously in X-ray for its first 10 hours from the precursor to the late decay phases. The observed fluxes increased by more than two orders of magnitude at its peak in X-ray and at least one in the UV as compared to quiescence. The peak 0.1-7.0 keV X-ray flux is derived from the two-temperature APEC model to be ~(8.4 +/- 0.6) x 10^-12 erg cm-2 s-1. Combining astrometric information from multiple X-ray observations in the quiescent and flare states, we identify the NIR counterpart of LMC 335 as the 2MASS source J05414534-6921512. The NIR color relations and spectroscopic parallax characterize the source as a Galactic K7-M4 dwarf at a foreground distance of (100 - 264) pc, implying a total energy output of the entire event of ~(0.4 - 2.9) x 10^35 erg. This report comprises detailed analyses of this late-K / early-M dwarf flare event that has the longest time coverage yet reported in the literature. The flare decay can be modeled with two exponential components with timescales of ~28 min and ~4 hours, with a single component decay firmly ruled out. The X-ray spectra during flare can be described by two components, a dominant high temperature component of ~40-60MK and a low temperature component of ~10MK, with a flare loop length of about 1.1-1.3 stellar radius.Comment: 35 pages, 6 figures, 5 tables, accepted for publication in Ap

    Nuclear isotope thermometry

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    We discuss different aspects which could influence temperatures deduced from experimental isotopic yields in the multifragmentation process. It is shown that fluctuations due to the finite size of the system and distortions due to the decay of hot primary fragments conspire to blur the temperature determination in multifragmentation reactions. These facts suggest that caloric curves obtained through isotope thermometers, which were taken as evidence for a first-order phase transition in nuclear matter, should be investigated very carefully.Comment: 9 pages, 7 figure

    Effect of isospin dependent cross-section on fragment production in the collision of charge asymmetric nuclei

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    To understand the role of isospin effects on fragmentation due to the collisions of charge asymmetric nuclei, we have performed a complete systematical study using isospin dependent quantum molecular dynamics model. Here simulations have been carried out for 124Xn+124Xn^{124}X_{n}+ ^{124}X_{n}, where n varies from 47 to 59 and for 40Ym+40Ym^{40}Y_{m}+ ^{40}Y_{m}, where m varies from 14 to 23. Our study shows that isospin dependent cross-section shows its influence on fragmentation in the collision of neutron rich nuclei

    O assistente social como mediador cultural em escolas públicas dos bairros de Guamá e Terra firme

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    I Congresso Internacional América Latina e Interculturalidade: América Latina e Caribe: cenários linguístico-culturais contemporâneos, 07, 08 e 09 de novembro de 2013 - UNILAA intervenção do Assistente Social nas atividades de arte e cultura nas instituições de ensino fundamental e médio nos bairros do Guamá e da Terra Firme. Estudos anteriores constatam que estes não são apenas espaços de violência, como registra a mídia. São espaços multiculturais e agregadores de cultura antiviolência, onde os sujeitos artistas utilizam a arte como meio de transformação social, através do método fenomenológico busco contribuir para a sistematização da intervenção do assistente social na área da educação e cultura, identificando as atividades de arte e cultura nas instituições de ensino fundamental e médio, importância nas instituições em que são desenvolvidas e habilidades requeridas ao profissional de Serviço Social. A metodologia conduziu a investigação nos respectivos bairros com os alunos que estudam nas instituições de ensino fundamental e médio nos bairros, por meio de aplicação de questionários sócio­econômico­cultural que ao definir cultura identificaram as manifestações culturais que estavam ocorrendo no mês (junho/2013) em que o questionário foi aplicado, quanto ao fazer profissional do Serviço Social, a maioria dos alunos da escola pública estadual relacionam o trabalho do assistente social com a prestação de ajuda e auxílio. Os alunos da escola pública federal demonstraram maior efetividade e segurança na resposta, em consonância com o Código de Ética do Assistente Social, também foi realizada entrevista semi­estruturada com a Assistente Social das instituições de ensino. Segundo a pesquisa identifica­se a sobrecarga do profissional do serviço social com as demandas postas pelos alunos no processo de ensino e aprendizagem, de tal modo que não possa acompanhar atividades de arte e cultura desenvolvidas nas instituições de ensino, e por meio de levantamentos bibliográficos e visitas de observação ao local de pesquisa foi possível identificar as atividades, projetos de extensão de arte e cultura nas instituições de ensino

    Space Shuttle/TDRSS communication and tracking systems analysis

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    In order to evaluate the technical and operational problem areas and provide a recommendation, the enhancements to the Tracking and Data Delay Satellite System (TDRSS) and Shuttle must be evaluated through simulation and analysis. These enhancement techniques must first be characterized, then modeled mathematically, and finally updated into LinCsim (analytical simulation package). The LinCsim package can then be used as an evaluation tool. Three areas of potential enhancements were identified: shuttle payload accommodations, TDRSS SSA and KSA services, and shuttle tracking system and navigation sensors. Recommendations for each area were discussed

    Measuring the Temperature of Hot Nuclear Fragments

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    A new thermometer based on fragment momentum fluctuations is presented. This thermometer exhibited residual contamination from the collective motion of the fragments along the beam axis. For this reason, the transverse direction has been explored. Additionally, a mass dependence was observed for this thermometer. This mass dependence may be the result of the Fermi momentum of nucleons or the different properties of the fragments (binding energy, spin etc..) which might be more sensitive to different densities and temperatures of the exploding fragments. We expect some of these aspects to be smaller for protons (and/or neutrons); consequently, the proton transverse momentum fluctuations were used to investigate the temperature dependence of the source

    Eye–hand coordination and its relationship with sensori-motor impairments in stroke survivors

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    Evidence based treatment for unstable slipped upper femoral epiphysis : systematic review and exploratory patient level analysis

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    The management of slipped upper femoral epiphysis is controversial and evolving as insight into the condition develops. Loder introduced the concept of slip stability and demonstrated a strong association between poor outcome and instability. Almost half of patients with unstable slip developed femoral head osteonecrosis. This has been influential in surgeons' choice of treatments. Some surgeons have adopted a minimal intervention approach such as pinning in situ or gentle reduction and pinning whereas others advocated an urgent open reduction and stabilisation of slip using various surgical techniques. In this review we analysed the influence of various interventions, timing of surgery and severity of the slip on the outcome of unstable slip

    How to monitor patient safety in primary care? Healthcare professionals’ views

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    Objective: To identify patient safety monitoring strategies in primary care. Design: Open-ended questionnaire survey. Participants/Setting: 113 healthcare professionals based in North-West London returned the survey from a group of 500 who were invited to participate achieving a response rate of 22.6 per cent. Method: A paper-based and equivalent online survey was developed and subjected to multiple stages of piloting. Respondents were asked to suggest strategies for monitoring patient safety in primary care. These monitoring suggestions were then subjected to a content frequency analysis which was conducted by two researchers. Outcome measures: Respondent-derived monitoring strategies. Results: In total, respondents offered 188 suggestions for monitoring patient safety in primary care. The content analysis revealed that these could be condensed into twenty-four different future monitoring strategies with varying levels of support. Most commonly, respondents supported the suggestion that patient safety can only be monitored effectively in primary care with greater levels of staffing or with additional resources. Discussion: This study identified twenty-four possible ways in which monitoring patient safety in North-West London primary care could be achieved. Future work should explore the feasibility of these monitoring strategies as well as the patients’ perspectives on how the safety of their care should be monitored
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