64 research outputs found

    Estimulação Térmica Dos EmbriÔes Da Linhagem RossŸ Em Escala Comercial

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    Artificial incubation is an essential process to obtain healthy birds with good performance; nevertheless, it requires sustained improvement. During this process, incubation temperature is considered a critical factor, which has been studied. The objective of this study was to evaluate the development of RossÂź embryos after hot and cold thermal stimulation. To this end, temperatures 1.39ÂșC above the standard temperature and a temperature fixed at 36.00ÂșC that varied 1.00 to 0.30ÂșC below the standard temperature were applied during the final embryonic development period (days 14 to 18) for three hours, on a commercial scale. Results revealed that hot and cold thermal stimulations did not cause embryo mortality; the hatching and chick quality index were maintained and even increased. Therefore, we believe that thermal stimulation has the potential to improve hatchery index, and thus grange performance; however, adjustments are needed, varying according to each individual hatchery, before it can used as a protocol. © 2016, Universidade Federal de Santa Maria. All rights reserved.4691668167

    Guided vortex motion in superconductors with a square antidot lattice

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    We have measured the in-plane anisotropy of the vortex mobility in a thin Pb film with a square array of antidots. The Lorentz force, acting on the vortices, was rotated by adding two perpendicular currents and keeping the amplitude of the net current constant. One set of voltage probes was used to detect the vortex motion. We show that the pinning landscape provided by the square antidot lattice influences the vortex motion in two different ways. First, the modulus of the vortex velocity becomes angular dependent with a lower mobility along the diagonals of the pinning array. Second, the vortex displacement is preferentially parallel to the principal axes of the underlying pinning lattice, giving rise to a misalignment between the vortex velocity and the applied Lorentz force. We show that this anisotropic vortex motion is temperature dependent and progressively fades out when approaching the normal state.Comment: 5 pages, 4 figure

    Parùmetros de cultivo e a enfermidade da mancha-branca em fazendas de camarÔes de Santa Catarina

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    O objetivo deste trabalho foi avaliar a relação entre parĂąmetros fĂ­sico-quĂ­micos e biolĂłgicos do cultivo de camarĂŁo com a enfermidade causada pelo vĂ­rus da sĂ­ndrome da mancha-branca (WSSV). Foram avaliadas a mortalidade, as caracterĂ­sticas fĂ­sicas e quĂ­micas da ĂĄgua e do solo, e foram realizados os exames e as anĂĄlises microscĂłpicas a fresco, presença de vĂ­brios na hemolinfa, alĂ©m do diagnĂłstico histopatolĂłgico e molecular (PCR) do WSSV, em viveiros de oito fazendas de Santa Catarina, entre 2008 e 2009. O vĂ­rus foi detectado em cinco fazendas com registros da enfermidade em ciclos anteriores. A temperatura da ĂĄgua foi semelhante entre as fazendas com e sem WSSV, e a mortalidade ocorreu a intervalos ascendentes entre 24,6 e 29,3ÂșC. NĂŁo foram encontradas diferenças significativas nos parĂąmetros de anĂĄlises microscĂłpicas a fresco, tempo de coagulação e presença de vĂ­brios na hemolinfa e sinais clĂ­nicos, entre viveiros com e sem WSSV. As concentraçÔes de nitrito, sĂ­lica, fenol e alcalinidade na ĂĄgua e pH do solo apresentaram diferenças significativas entre os viveiros afetados ou nĂŁo por WSSV. Os valores de nitrito, sĂ­lica e pH do solo estavam dentro dos limites recomendados para o cultivo de camarĂ”es, no entanto, isto nĂŁo ocorreu com a alcalinidade e a concentração de fenol, o que sugere uma relação dos Ășltimos com a manifestação da enfermidade da mancha-branca

    Performance of the CMS Level-1 trigger in proton-proton collisions at √s = 13 TeV

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    At the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13\TeV. During Run 2 (years 2015–2018) the LHC eventually reached a luminosity of 2.1× 1034^{34} cm−2^{-2}s−1^{-1}, almost three times that reached during Run 1 (2009–2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). The CMS Level-1 trigger was upgraded prior to 2016 to improve the selection of physics events in the challenging conditions posed by the second run of the LHC. This paper describes the performance of the CMS Level-1 trigger upgrade during the data taking period of 2016–2018. The upgraded trigger implements pattern recognition and boosted decision tree regression techniques for muon reconstruction, includes pileup subtraction for jets and energy sums, and incorporates pileup-dependent isolation requirements for electrons and tau leptons. In addition, the new trigger calculates high-level quantities such as the invariant mass of pairs of reconstructed particles. The upgrade reduces the trigger rate from background processes and improves the trigger efficiency for a wide variety of physics signals

    Measurement of prompt D0^{0} and D‟\overline{D}0^{0} meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at root SNN\sqrt{S_{NN}} = 5.02 TeV

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    The strong Coulomb field created in ultrarelativistic heavy ion collisions is expected to produce a rapiditydependent difference (Av2) in the second Fourier coefficient of the azimuthal distribution (elliptic flow, v2) between D0 (uc) and D0 (uc) mesons. Motivated by the search for evidence of this field, the CMS detector at the LHC is used to perform the first measurement of Av2. The rapidity-averaged value is found to be (Av2) = 0.001 ? 0.001 (stat)? 0.003 (syst) in PbPb collisions at ?sNN = 5.02 TeV. In addition, the influence of the collision geometry is explored by measuring the D0 and D0mesons v2 and triangular flow coefficient (v3) as functions of rapidity, transverse momentum (pT), and event centrality (a measure of the overlap of the two Pb nuclei). A clear centrality dependence of prompt D0 meson v2 values is observed, while the v3 is largely independent of centrality. These trends are consistent with expectations of flow driven by the initial-state geometry. ? 2021 The Author. Published by Elsevier B.V. This is an open access article under the CC BY licens

    Studies of charm and beauty hadron long-range correlations in pp and pPb collisions at LHC energies

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    Measurement of the CP-violating phase ϕs_{s} in the B0^{0}s_{s}→J/ψ φ(1020) →ΌâșΌ⁻KâșK⁻ channel in proton-proton collisions at √s = 13 TeV

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