9,026 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 Ă©vĂ©nements de prĂ©cipitations qui sont supĂ©rieurs au 97e rang centile des prĂ©cipitations quotidiennes Ă  Iqaluit, Nunavut, durant la saison froide, soit d'octobre Ă  avril. Cela correspond Ă  un seuil de prĂ©cipitation de 9,5 mm. Nous dĂ©crivons les caractĂ©ristiques de 194 Ă©vĂ©nements de prĂ©cipitations majeures qui se sont dĂ©roulĂ©s entre 1955 et 1996. Selon les donnĂ©es traitĂ©es par NCEP-NCAR et NARR , les systĂšmes dĂ©pressionnaires responsables de ces Ă©vĂ©nements ont Ă©tĂ© classĂ©s en quatre catĂ©gories : sud, ouest, Atlantique et autre. Les systĂšmes provenant du sud et de l'Atlantique ont eu tendance Ă  ĂȘtre associĂ©s aux Ă©vĂ©nements les plus sĂ©vĂšres. Plus que la vitesse des systĂšmes dĂ©pressionnaires, la durĂ©e et le niveau des prĂ©cipitations ont Ă©tĂ© des facteurs dĂ©terminants sur les accumulations. La neige a Ă©tĂ© le principal type de prĂ©cipitation. La prĂ©sence de fronts chauds en surface a reprĂ©sentĂ© une caractĂ©ristique troposphĂ©rique commune de ces Ă©vĂ©nements et la topographie a influencĂ© de maniĂšre importante la direction du vent Ă  la surface. Aucune tendance de la frĂ©quence des Ă©vĂ©nements de prĂ©cipitations majeures n'est Ă©vidente

    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

    Study of η − ηâ€Č mixing from measurement of B (s)0 → J/ψη(â€Č) decay rates

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    A study of B and B0 s meson decays into J/ψη and J/ψη0 final states is performed using a data set of proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, collected by the LCHb experiment and corresponding to 3.0 fb−1 of integrated luminosity. The decay B0 → J/ψη0 is observed for the first time. The following ratios of branching fractions are measured: B(B0 → J/ψη0 ) B(B0 s → J/ψη0) = (2.28 ± 0.65 (stat) ± 0.10 (syst) ± 0.13 (fs/fd)) × 10−2 , B(B0 → J/ψη) B(B0 s → J/ψη) = (1.85 ± 0.61 (stat) ± 0.09 (syst) ± 0.11 (fs/fd)) × 10−2 , where the third uncertainty is related to the present knowledge of fs/fd, the ratio between the probabilities for a b quark to form a B0 s or a B0 meson. The branching fraction ratios are used to determine the parameters of η−η 0 meson mixing. In addition, the first evidence for the decay B0 s → ψ(2S)η 0 is reported, and the relative branching fraction is measured, B(B0 s → ψ(2S)η 0 ) B(B0 s → J/ψη0) = (38.7 ± 9.0 (stat) ± 1.3 (syst) ± 0.9(B)) × 10−2 , where the third uncertainty is due to the limited knowledge of the branching fractions of J/ψ and ψ(2S) mesons
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