2,934 research outputs found

    Effect of Different Urine Cow Nitrogen Rates and Different Moisture Conditions on Nitrogen Mineralization in an Andisol from Southern Chile

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    Urea present in cattle urine contributes large amounts of nitrogen (N) to grazed pastures, which can be an equivalent to approximately 1000 kg N ha−1. However, there are no studies in volcanic soils of southern Chile on the effect of different concentrations of urinary N deposited in the soil, nor of different wetting and drying conditions mimicking the variation of weather conditions on the nitrification process, from urea to NH4+ and total oxidized nitrogen (TON), throughout time. In addition, the inhibition on nitrification driven by the accumulation of NH3 at high rates of N applied to an Andisol have not been evaluated. Fresh cattle urine was applied at three different rates of N equivalent to 247 kg N ha−1 (Low N), 461 kg N ha−1 (Medium N), 921 kg N ha−1 (High N), and de-ionized water as Control. Further, three moisture conditions were imposed: constant moisture (CM), drying-rewetting (DRW) cycles at 7 days interval, and soil drying (SD). Destructive soil cores samples were evaluated for top and bottom halves individually every 7 days over a 36-d period to measure changes on inorganic N and pH. There were no interaction effects for N rates and soil moisture. The main effect of the different rates of N on mineralization was significant throughout the incubation period, while the effect of the different moisture conditions was var-iable over time. The High N was associated with elevated NH3 concentrations and could explain that total N mineralization was partially inhibited. These results suggest that the presence of different nitrifying microorganisms in the soil under different chemical and physical conditions determines nitrification, thus, the oxidation of ammonia should be studied in more detail as the first step of nitrification, specifically in volcanic soils

    Physicochemical Characterization of Mesquite Flour (<em>Prosopis laevigata</em>), Particle Size Distribution, Morphology, Isosteric Heat, and Rheology

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    Mesquite pods were dried and milled. The physicochemical properties of mesquite flour were characterized. The pods were dried at 60°C, 15% RH, and 2 m/s airflow. After drying, two types of milling were applied: (1) industrial blade mill and (2) Blender, and the nutritional composition was determined. The sorption isotherms were obtained at 30, 35, 40, and 45°C for a range of water activity of 0.07–0.9. The particle size distribution and the average particle size of the flours were characterized by means of diffraction of blue laser light; furthermore, the morphology was analyzed by (SEM). The powders were also analyzed by DSC. Alveography was applied to study the rheology of the flour. Mesquite powders are highly hygroscopic, and the (GAB) model displays a good description of the experimental data. Flours expose different morphologies depending on the milling technique; a more homogeneous powder was obtained from the industrial blade mill. Rheological characterization indicates that mesquite flour decreases the tenacity and extensibility of the flour mixture. According to DSC, the flours are very stable over a wide temperature range from 0 to 120°C, and the thermograms indicate a transition of proteins affected by high-molecular-weight carbohydrates and moisture content

    Inteligencia intercultural para los negocios

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    El PAP de “Inteligencia cultural y comercial para los negocios internacionales” del periodo otoño 2022 (del 15 de agosto al 5 de diciembre) tiene como propĂłsito general, lograr la participaciĂłn exitosa de una empresa (en este caso artistas) en una misiĂłn internacional, feria o exposiciĂłn, dotĂĄndola de todos los elementos necesarios para lograrlo. Entre los principales objetivos y alcances del PAP estĂĄn: ayudar a dos artistas a poder participar en una feria internacional, fortalecer su posicionamiento en mercados internacionales y desarrollar capacidades empresariales incorporando el anĂĄlisis cultural como parte del valor agregado. La metodologĂ­a con la que se realizĂł este proyecto consistiĂł en que al tener a dos artistas con el interĂ©s de participar en una feria internacional (cada artista tenĂ­a una feria diferente) se dividiĂł al grupo en dos equipos con el propĂłsito de que cada equipo elaborarĂĄ un documento o guĂ­a estructurada mediante una rĂșbrica sobre los aspectos importantes de cubrir y que cuyo contenido brindara las herramientas y la informaciĂłn necesaria a los artistas para que pudieran participar en las ferias de su interĂ©s. Los resultados o productos mĂĄs relevantes de la elaboraciĂłn de este proyecto son dos guĂ­as con informaciĂłn mportante sobre la logĂ­stica, operativa, financiera, cultural, de ocio, apoyos a los artistas e informaciĂłn de las ferias en las que los artistas desean participar. A partir de este anĂĄlisis los artistas podrĂĄn evaluar y tomar mejores decisiones con respecto a su participaciĂłn en la feria internacional.ITESO, A.C

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+→Ό+ÎœW^+ \rightarrow \mu^+\nu and W−→Ό−ΜW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

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    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <pT,assoc<pT,trig< < p_{\rm{T}, assoc} < p_{\rm{T}, trig} < 5.0 GeV/cc is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range ∣η∣<0.9|\eta|<0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161

    Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

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    A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino

    Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

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    Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a âˆŁÎ”Î·âˆŁ|\Delta \eta| gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of v2{4}v_{2}\{4\} to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find v2{4}≃v2{6}≠0v_{2}\{4\} \simeq v_{2}\{6\}\neq 0 which is indicative of a Bessel-Gaussian function for the v2v_{2} distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a âˆŁÎ”Î·âˆŁ>1.4|\Delta\eta| > 1.4 gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
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