8,535 research outputs found

    Major Cold-Season Precipitation Events at Iqaluit, Nunavut

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    This study focuses on cold-season (October-April) precipitation events at Iqaluit, Nunavut, that exceed the 97th percentile of daily corrected precipitation accumulation. This corresponds to a threshold of 9.5 mm. The characteristics of 194 major precipitation events are described for the 1955 - 96 period. On the basis of NCEP-NCAR and NARR reanalysis data, these events were classified into four storm tracks: south, west, Atlantic, and other. South- and Atlantic-originating systems tended to be associated with the most severe events. The duration and precipitation rate of the events, rather than the speed of motion, were critical factors influencing precipitation accumulation. Snow was the dominant precipitation type. Surface warm frontal passage was a common tropospheric feature, and the topography was important in terms of altering surface wind direction during the events. No significant trend in the occurrence of major precipitation is evident.Ce travail traite des événements de précipitations qui sont supérieurs au 97e rang centile des précipitations quotidiennes à Iqaluit, Nunavut, durant la saison froide, soit d'octobre à avril. Cela correspond à un seuil de précipitation de 9,5 mm. Nous décrivons les caractéristiques de 194 événements de précipitations majeures qui se sont déroulés entre 1955 et 1996. Selon les données traitées par NCEP-NCAR et NARR , les systèmes dépressionnaires responsables de ces événements ont été classés en quatre catégories : sud, ouest, Atlantique et autre. Les systèmes provenant du sud et de l'Atlantique ont eu tendance à être associés aux événements les plus sévères. Plus que la vitesse des systèmes dépressionnaires, la durée et le niveau des précipitations ont été des facteurs déterminants sur les accumulations. La neige a été le principal type de précipitation. La présence de fronts chauds en surface a représenté une caractéristique troposphérique commune de ces événements et la topographie a influencé de manière importante la direction du vent à la surface. Aucune tendance de la fréquence des événements de précipitations majeures n'est évidente

    Application of large area SiPMs for the readout of a plastic scintillator based timing detector

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    In this study an array of eight 6 mm x 6 mm area SiPMs was coupled to the end of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm x 6 cm x 1 cm and 120 cm x 11 cm x 2.5 cm have been studied. An 8-channel SiPM anode readout ASIC (MUSIC R1) based on a novel low input impedance current conveyor has been used to read out and amplify SiPMs independently and sum the signals at the end. Prospects for applications in large-scale particle physics detectors with timing resolution below 100 ps are provided in light of the results

    Application of large area SiPMs for the readout of a plastic scintillator based timing detector

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    In this study an array of eight 6 mm x 6 mm area SiPMs was coupled to the end of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm x 6 cm x 1 cm and 120 cm x 11 cm x 2.5 cm have been studied. An 8-channel SiPM anode readout ASIC (MUSIC R1) based on a novel low input impedance current conveyor has been used to read out and amplify SiPMs independently and sum the signals at the end. Prospects for applications in large-scale particle physics detectors with timing resolution below 100 ps are provided in light of the results

    Effects of Residue Background Events in Direct Dark Matter Detection Experiments on the Determination of the WIMP Mass

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    In the earlier work on the development of a model-independent data analysis method for determining the mass of Weakly Interacting Massive Particles (WIMPs) by using measured recoil energies from direct Dark Matter detection experiments directly, it was assumed that the analyzed data sets are background-free, i.e., all events are WIMP signals. In this article, as a more realistic study, we take into account a fraction of possible residue background events, which pass all discrimination criteria and then mix with other real WIMP-induced events in our data sets. Our simulations show that, for the determination of the WIMP mass, the maximal acceptable fraction of residue background events in the analyzed data sets of O(50) total events is ~20%, for background windows of the entire experimental possible energy ranges, or in low energy ranges; while, for background windows in relatively higher energy ranges, this maximal acceptable fraction of residue background events can not be larger than ~10%. For a WIMP mass of 100 GeV with 20% background events in the windows of the entire experimental possible energy ranges, the reconstructed WIMP mass and the 1-sigma statistical uncertainty are ~97 GeV^{+61%}_{-35%} (~94 GeV^{+55%}_{-33%} for background-free data sets).Comment: 27 pages, 22 eps figures; v2: revised version for publication, references added and update

    Study of a Solution with COTS for the LHCb Calorimeter Upgrade

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    AbstractWe present a solution made out of Components Out of Shelf (COTS) for the analog processing of the signal of the LHCb calorimeters in the framework of the foreseen upgrade of the detector. The present proposal is based on the current functional solution, yet, to meet the stringent noise requirements, a number of modifications are proposed. Preliminary results on the prototype boards show promising results

    Health benefits of physical activity related to an urban riverside regeneration

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    The promotion of physical activity through better urban design is one pathway by which health and well-being improvements can be achieved. This study aimed to quantify health and health-related economic impacts associated with physical activity in an urban riverside park regeneration project in Barcelona, Spain. We used data from Barcelona local authorities and meta-analysis assessing physical activity and health outcomes to develop and apply the “Blue Active Tool”. We estimated park user health impacts in terms of all-cause mortality, morbidity (ischemic heart disease; ischemic stroke; type 2 diabetes; cancers of the colon and breast; and dementia), disability-adjusted life years (DALYs) and health-related economic impacts. We estimated that 5753 adult users visited the riverside park daily and performed different types of physical activity (walking for leisure or to/from work, cycling, and running). Related to the physical activity conducted on the riverside park, we estimated an annual reduction of 7.3 deaths (95% CI: 5.4; 10.2), and 6.2 cases of diseases (95% CI: 2.0; 11.6). This corresponds to 11.9 DALYs (95% CI: 3.4; 20.5) and an annual health-economic impact of 23.4 million euros (95% CI: 17.2 million; 32.8 million). The urban regeneration intervention of this riverside park provides health and health-related economic benefits to the population using the infrastructure

    A Case of Urogenital Human Schistosomiasis from a Non-endemic Area

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    © 2015 Calvo-Cano et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article

    Topological and geometrical restrictions, free-boundary problems and self-gravitating fluids

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    Let (P1) be certain elliptic free-boundary problem on a Riemannian manifold (M,g). In this paper we study the restrictions on the topology and geometry of the fibres (the level sets) of the solutions f to (P1). We give a technique based on certain remarkable property of the fibres (the analytic representation property) for going from the initial PDE to a global analytical characterization of the fibres (the equilibrium partition condition). We study this analytical characterization and obtain several topological and geometrical properties that the fibres of the solutions must possess, depending on the topology of M and the metric tensor g. We apply these results to the classical problem in physics of classifying the equilibrium shapes of both Newtonian and relativistic static self-gravitating fluids. We also suggest a relationship with the isometries of a Riemannian manifold.Comment: 36 pages. In this new version the analytic representation hypothesis is proved. Please address all correspondence to D. Peralta-Sala
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