420 research outputs found

    DIAGNÓSTICO DE INDICADORES DE CALIDAD FÍSICO-QUÍMICA DEL AGUA EN AFLUENTES DEL RÍO ATOYAC - DIAGNOSIS OF INDICATORS OF PHYSICAL-CHEMICAL QUALITY OF WATER IN AFFLUENTS OF THE ATOYAC RIVER

    Get PDF
    En la Región de Texmelucan, Pue., las principales fuentes de agua para riego provienen del deshielo de los volcanes y de pozos profundos; estas fuentes satisfacen las necesidades de agua del área agrícola de Texmelucan y sus alrededores. Sin embargo, alrededor de 350 productores también emplean aguas residuales para regar sus cultivos. Se evaluaron algunos parámetros que inciden en la calidad físico-química del agua cuando se utiliza con fines de riego (pH, CE, Ca2+, Mg2+, K+, PO42-, SO42-, CO32-, HCO3-, Na+, B y Cl-). Se realizó un muestreo aleatorio en 28 puntos, en afluentes del cauce del Río Atoyac, donde se tomaron muestras de agua para realizar el análisis físico-químico correspondiente. Los resultados muestran que la CE osciló entre 0 y 0.875 dS m-1; el 64.28% correspondió a aguas de baja salinidad y bajo contenido de sodio (clase C1S1), el 28.57% a aguas con salinidad media y bajo contenido de sodio (clase C2S1) y el 7.15% a aguas de salinidad alta y bajo contenido de sodio (clase C3S1). En promedio, el Ca (0.98 meq L-1) y Mg (1.11 meq L-1) estuvieron presentes en mayor concentración, lo que modificó favorablemente los valores de la relación de adsorción de sodio (RAS). Los iones bicarbonato (HCO3-) en el agua presentaron una media de 1.83 meq L-1. La concentración de Cl-, HCO3-, CO3-2, B y SO4-2 no ha afectado a los cultivos establecidos y la concentración de PO42- es un aporte significativo a los cultivos. Estos resultados indican que la región de Texmelucan, Pue., tiene agua apta para el riego desde el punto de vista físico-químico; sin considerar el contenido de metales pesados ni análisis biológicos de la misma

    Moving towards public policy-ready science: philosophical insights on the social-ecological systems perspective for conservation science

    Get PDF
    The social-ecological systems (SES) perspective stems from the need to rethink the ways humans relate to the environment, given the evidence that conventional conservation and management approaches are often ineffective in dealing with complex socio-environmental problems. The SES approach conceives non-scientific and scientific knowledge as equally necessary in the process of management and public policy formation. Thus, the adoption of the SES approach must also serve to make better decisions about what kind of science and technology would be ‘public policy-ready’ (as well as also ‘policy-relevant’); that is, a science oriented and conceived to provide concrete solutions to societal needs and demands. Here we review and reinterpret the SES perspective as a real paradigm change for conservation science. Under the lenses of philosophy, we try to untangle some weak points of the SES approach in order to advance to a conservation science closer to the process of science-based public policy creation and to enhance the intertwining with other types of knowledge. In this sense, we discuss how co-production of knowledge and decision-making process under the SES perspective are a huge step forward towards fulfilling the need to bring increasingly closer the spheres of science and policy, narrowing its interface.Fil: Sala, Juan Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Torchio, Gabriela María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentin

    Standalone vertex finding in the ATLAS muon spectrometer

    Get PDF
    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

    Get PDF
    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

    Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

    Get PDF
    A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction

    Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

    Get PDF
    A measurement of the production cross-section for top quark pairs(\ttbar) in pppp collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron ee or muon μ\mu) with large missing transverse energy and at least four jets, and dilepton (eeee, μμ\mu\mu or eμe\mu) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be 12.2±3.912.2 \pm 3.9 events and 2.5±0.62.5 \pm 0.6 events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

    Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

    Get PDF
    A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN

    Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of √s=7 TeV proton-proton collisions

    Get PDF
    Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

    Measurement of the production cross section for W-bosons in association with jets in pp collisions at s=7 TeV with the ATLAS detector

    Get PDF

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

    Get PDF
    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal
    corecore