2,320 research outputs found

    The Front End Electronics of the Scintillator Pad Detector of LHCb Calorimeter

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    In this paper the Front End electronics of the Scintillator Pad Detector (SPD) is outlined. The SPD is a sub-system of the Calorimeter of the LHCb experiment designed to discriminate between charged and neutral particles for the first level trigger. The system design is presented, describing its different functionalities implemented through three different cards and several ASICs. These functionalities are signal processing and digitization, data transmission, interface with control and timing systems of the experiment, low voltage power supply distribution and monitoring. Special emphasis is placed on installation and commissioning subjects such as cabling, grounding, shielding and power distribution

    Health Care Workers Occupational Accidents in a Brazilian Hospital

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    Universidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

    Health Care Worker Immune Status and Risk Perception of Acquisition of Vaccine Preventable Diseases

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    Universidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

    Searches for Λ0b and Ξ0b decays to K0Spπ− and K0SpK− final states with first observation of the Λ0b→K0Spπ− decay

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    A search for previously unobserved decays of beauty baryons to the final states K0 S pπ− and K0 S pK− is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb−1 of pp collisions. The Λ 0 b → K0pπ− decay is observed with a significance of 8.6 σ, with branching fraction B(Λ 0 b → K0 pπ−) = (1.26 ± 0.19 ± 0.09 ± 0.34 ± 0.05) × 10−5 , where the uncertainties are statistical, systematic, from the ratio of fragmentation fractions fΛ0 b /fd, and from the branching fraction of the B0→ K0π +π − normalisation channel, respectively. A first measurement is made of the CP asymmetry, giving ACP (Λ 0 b → K0 pπ−) = 0.22 ± 0.13 (stat) ± 0.03 (syst). No significant signals are seen for Λ 0 b → K0 S pK− decays, Ξ0 b decays to both the K0 S pπ− and K0 S pK− final states, and the Λ 0 b → D− s (→ K0 SK−)p decay, and upper limits on their branching fractions are reported

    Estudio teórico de algunas propiedades termodinámicas de los ácidos grasos obtenidos como destilados en la desodorización de aceites comestibles

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    Nowadays the feasibility of a change of technology in the deodorization stage of edible vegetable oil refining is being investigated. The proposed technology involves a modification in the composition of the distillates coming from the deodorization stage and their further treatment To design the apparatus which are required by the proposed technology it is necessary to study the physical properties of the distillates. The thermodynamic properties of the fatty acids: palmitic, stearic, oleic and linoleic, which are the principal components produced at the deodorization stage have been studied. The properties that have been studied were those corresponding to the critical point (critical temperature, pressure and volume), the vapour pressure-temperature relation and the latent heat of vaporisation. Different methods to estimate the above mentioned properties and some experimental published data have been compared.Estudio teórico de algunas propiedades termodinámicas de los ácidos grasos obtenidos como destilados en la desodorización de aceites comestibles Actualmente se investiga la viabilidad de un cambio en la tecnología de la desodorización de aceites comestibles que afecta a la composición de los destilados que se obtienen en el proceso y al tratamiento de los mismos. El diseño de los equipos que conlleva este cambio de tecnología requiere el estudio de propiedades físicas de los destilados. Se han estudiado algunas propiedades termodinámicas de los ácidos palmítico, esteárico, oleico y linoleico, componentes mayoritarios resultantes del proceso de desodorización. Las propiedades estudiadas han sido las correspondientes al punto crítico (temperatura, presión y volumen críticos), las curvas de presión de vapor en función de la temperatura y el calor latente de vaporización. Se han recogido distintos métodos de estimación de las mencionadas propiedades y algunos datos experimentales, y se han comparado los resultados obtenidos

    Stability and Electronic Properties of TiO2 Nanostructures With and Without B and N Doping

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    We address one of the main challenges to TiO2-photocatalysis, namely band gap narrowing, by combining nanostructural changes with doping. With this aim we compare TiO2's electronic properties for small 0D clusters, 1D nanorods and nanotubes, 2D layers, and 3D surface and bulk phases using different approximations within density functional theory and GW calculations. In particular, we propose very small (R < 0.5 nm) but surprisingly stable nanotubes with promising properties. The nanotubes are initially formed from TiO2 layers with the PtO2 structure, with the smallest (2,2) nanotube relaxing to a rutile nanorod structure. We find that quantum confinement effects - as expected - generally lead to a widening of the energy gap. However, substitutional doping with boron or nitrogen is found to give rise to (meta-)stable structures and the introduction of dopant and mid-gap states which effectively reduce the band gap. Boron is seen to always give rise to n-type doping while depending on the local bonding geometry, nitrogen may give rise to n-type or p-type doping. For under coordinated TiO2 surface structures found in clusters, nanorods, nanotubes, layers and surfaces nitrogen gives rise to acceptor states while for larger clusters and bulk structures donor states are introduced

    Observation of Z production in proton-lead collisions at LHCb

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    The first observation of Z boson production in proton-lead collisions at a centreof-mass energy per proton-nucleon pair of √ sNN = 5 TeV is presented. The data sample corresponds to an integrated luminosity of 1.6 nb−1 collected with the LHCb detector. The Z candidates are reconstructed from pairs of oppositely charged muons with pseudorapidities between 2.0 and 4.5 and transverse momenta above 20 GeV/c. The invariant dimuon mass is restricted to the range 60 − 120 GeV/c2 . The Z production cross-section is measured to be σZ→µ+µ− (fwd) = 13.5 +5.4 −4.0 (stat.) ± 1.2(syst.) nb in the direction of the proton beam and σZ→µ+µ− (bwd) = 10.7 +8.4 −5.1 (stat.) ± 1.0(syst.) nb in the direction of the lead beam, where the first uncertainty is statistical and the second systematic
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