121 research outputs found

    Liming and fertilization on espinheira-santa [Maytenus ilicifolia (Schrad.) Planch.] growth in greenhouse

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    Devido a pouca informação existente sobre adubação para espinheira-santa, e a crescente procura desta espécie, o objetivo deste trabalho foi avaliar o efeito da calagem, adubação orgânica, mineral e omissão de nutrientes sobre o crescimento de Maytenus ilicifolia. As mudas foram produzidas por sementes e, em agosto de 2006, foram transferidas para vasos com 8 dm³ contendo Latossolo Vermelho Distrófico. O experimento foi conduzido em casa de vegetação no delineamento inteiramente casualizado em arranjo bifatorial, totalizando 12 tratamentos com 4 repetições, cujos tratamentos foram: sem adubação com calagem (T1), sem adubação e sem calagem (T7), adubação orgânica (T2 e T8), adubação mineral NPK (T3 e T9), mineral -N (T4 e T10), mineral -P (T5 e T11) e mineral -K (T6 e T12). Os tratamentos T1 ao T6 receberam calcário na dose equivalente a 7,06 t ha-1 de carbonato de cálcio e os tratamentos T7 ao T12 foram testados na ausência de calagem. Após 314 dias da instalação do experimento, foram analisadas as variáveis: massa seca foliar (MSF), massa seca do caule (MSC) e da raiz (MSR), massa seca da parte aérea (MSPA), área foliar (AF), volume radicular (VR), altura (H), diâmetro (D), relação raiz parte aérea (R/PA) e relação altura diâmetro (H/D). A partir dos resultados conclui-se que a calagem, quando utilizada como prática isolada, não resulta em benefícios significativos ao crescimento das plantas. Na presença de calagem, tanto a adubação mineral quanto a orgânica podem ser utilizadas. Na ausência de calagem, a adubação orgânica mostrou-se mais favorável em estimular o crescimento das plantas. Em condições de adubação mineral, independente da presença ou não da calagem, o fósforo mostrou-se importante à nutrição de espinheira-santa.Since there is scarce information about fertilization for espinheira-santa and an increasing search for this species, the present study aimed to evaluate the effect of liming, organic and mineral fertilization, and nutrient omission on Maytenus ilicifolia growth. Seedlings were produced from seeds, and in August 2006 they were transferred to 8 dm³ pots containing Dystrophic Red Latosol. The experiment was carried out in a greenhouse and the design was completely randomized, in bi-factorial arrangement, totaling 12 treatments and four replicates; treatments were: without fertilization and with liming (T1), without fertilization and without liming (T7), organic fertilization (T2 and T8), mineral fertilization NPK (T3 and T9), mineral -N (T4 and T10), mineral -P (T5 and T11) and mineral -K (T6 and T12). T1 to T6 received lime at the dose equivalent to 7.06 t ha-1 calcium carbonate, and T7 to T12 were tested in the absence of liming. After 314 days of the experiment installation, the following variables were analyzed: leaf dry mass (LDM), stem (STDM) and root dry mass (RDM), shoot dry mass (SDM), leaf area (LA), root volume (RV), height (H), diameter (D), root and shoot ratio (R/S), and height and diameter ratio (H/D). Liming alone does not result in significant benefits to plant growth. In the presence of liming, both mineral and organic fertilization can be employed. In the absence of liming, organic fertilization showed to be more favorable in stimulating plant growth. Under mineral fertilization conditions, irrespective of the presence or absence of liming, phosphorus showed to be important for the nutrition of espinheira-santa

    The performance of the jet trigger for the ATLAS detector during 2011 data taking

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    The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction

    Measurement of the branching ratio Γ(Λb⁰ → ψ(2S)Λ0)/Γ(Λb⁰ → J/ψΛ0) with the ATLAS detector

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    An observation of the Λb0ψ(2S)Λ0\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0 decay and a comparison of its branching fraction with that of the Λb0J/ψΛ0\Lambda_b^0 \rightarrow J/\psi \Lambda^0 decay has been made with the ATLAS detector in proton--proton collisions at s=8\sqrt{s}=8\,TeV at the LHC using an integrated luminosity of 20.620.6\,fb1^{-1}. The J/ψJ/\psi and ψ(2S)\psi(2S) mesons are reconstructed in their decays to a muon pair, while the Λ0pπ\Lambda^0\rightarrow p\pi^- decay is exploited for the Λ0\Lambda^0 baryon reconstruction. The Λb0\Lambda_b^0 baryons are reconstructed with transverse momentum pT>10p_{\rm T}>10\,GeV and pseudorapidity η<2.1|\eta|<2.1. The measured branching ratio of the Λb0ψ(2S)Λ0\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0 and Λb0J/ψΛ0\Lambda_b^0 \rightarrow J/\psi \Lambda^0 decays is Γ(Λb0ψ(2S)Λ0)/Γ(Λb0J/ψΛ0)=0.501±0.033(stat)±0.019(syst)\Gamma(\Lambda_b^0 \rightarrow \psi(2S)\Lambda^0)/\Gamma(\Lambda_b^0 \rightarrow J/\psi\Lambda^0) = 0.501\pm 0.033 ({\rm stat})\pm 0.019({\rm syst}), lower than the expectation from the covariant quark model.Comment: 12 pages plus author list (28 pages total), 5 figures, 1 table, published on Physics Letters B 751 (2015) 63-80. All figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2013-08

    Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

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    This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

    Search for TeV-scale gravity signatures in high-mass final states with leptons and jets with the ATLAS detector at sqrt [ s ] = 13TeV

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    A search for physics beyond the Standard Model, in final states with at least one high transverse momentum charged lepton (electron or muon) and two additional high transverse momentum leptons or jets, is performed using 3.2 fb−1 of proton–proton collision data recorded by the ATLAS detector at the Large Hadron Collider in 2015 at √s = 13 TeV. The upper end of the distribution of the scalar sum of the transverse momenta of leptons and jets is sensitive to the production of high-mass objects. No excess of events beyond Standard Model predictions is observed. Exclusion limits are set for models of microscopic black holes with two to six extra dimensions
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