16 research outputs found

    Hydraulic modeling during filling and emptying processes in pressurized pipelines: a literature review

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    [EN] Filling and emptying processes are common maneuvers while operating, controlling and managing water pipeline systems. Currently, these operations are executed following recommendations from technical manuals and pipe manufacturers; however, these recommendations have a lack of understanding about the behavior of these processes. The application of mathematical models considering transient flows with entrapped air pockets is necessary because a rapid filling operation can cause pressure surges due to air pocket compressions, while an uncontrolled emptying operation can generate troughs of sub-atmospheric pressure caused by air pocket expansion. Depending on pipe and installation conditions, either situation can produce a rupture of pipe systems. Recently, reliable mathematical models have been developed by different researchers. This paper reviews and compares various mathematical models to simulate these processes. Water columns can be analyzed using a rigid water column model, an elastic water model, or 2D/3D CFD models; air-water interfaces using a piston-flow model or more complex models; air pockets through a polytropic model; and air valves using an isentropic nozzle flow or similar approaches. This work can be used as a starting point for planning filling and emptying operations in pressurized pipelines. Uncertainties of mathematical models of two-phases flow concerning to a non-variable friction factor, a polytropic coefficient, an air pocket sizes and an air valve behavior are identified.This work was supported by the Program Fondecyt Regular (Chile) [Project 1180660]; Fundacion Centro de Estudios Intedisciplinarios Basicos y Aplicados, CEIBA (Colombia).Fuertes-Miquel, VS.; Coronado-Hernández, OE.; Mora-Melia, D.; Iglesias Rey, PL. (2019). Hydraulic modeling during filling and emptying processes in pressurized pipelines: a literature review. Urban Water Journal. 16(4):299-311. https://doi.org/10.1080/1573062X.2019.1669188S29931116

    Desafíos y estrategias para la traducción del texto de Matemática Álgebra y Teoría de Números de L. Koulikov y sus posibles soluciones

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    La Matemática es una de las ciencias más antiguas que el ser humano ha estudiado e investigado y está presente en todos los ámbitos de nuestra vida cotidiana. Los traductores además de enfrentarse a las dificultades que presenta la traducción, sus marcas (lexicales, gramaticales y fonológicas) así como el estilo del texto, deben tener en cuenta que las marcas estilísticas en una lengua, pueden no serlo en otra, y mucho más en el campo de la Matemática ya que ésta debe ser completamente clara, puesto que es un tema complejo , y el no interpretar de manera correcta el sentido del texto puede distorsionar el sentido original del autor, una mala explicación puede variar el sentido de todo, por lo que debe cuidar que la calidad de la traducción sea equivalente a las del texto original, sin desatender por ello la integridad de su contenido. Así que uno de los desafíos al traducir este texto de Álgebra es encontrar en nuestra propia lengua términos que expresen con mayor grado de fidelidad posible el sentido de éste, lo cual es muy difícil sino se tiene un dominio correcto de los términos que se utilizan en el campo de la Matemátic

    Study of the spin and parity of the Higgs boson in diboson decays with the ATLAS detector

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    Studies of the spin, parity and tensor couplings of the Higgs boson in the H→ZZ∗→4ℓ, H→WW∗→eνμν and H→γγ decay processes at the LHC are presented. The investigations are based on 25fb−1 of pp collision data collected by the ATLAS experiment at √s=7 TeV and √s=8 TeV. The Standard Model (SM) Higgs boson hypothesis, corresponding to the quantum numbers JP=0+, is tested against several alternative spin scenarios, including non-SM spin-0 and spin-2 models with universal and non-universal couplings to fermions and vector bosons. All tested alternative models are excluded in favour of the SM Higgs boson hypothesis at more than 99.9 % confidence level. Using the H → ZZ∗ → 4ℓ and H → WW∗ → eνμν decays, the tensor structure of the interaction between the spin-0 boson and the SM vector bosons is also investigated. The observed distributions of variables sensitive to the non-SM tensor couplings are compatible with the SM predictions and constraints on the non-SM couplings are derived

    Search for the Standard Model Higgs boson decay to μ+μ− with the ATLAS detector

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    A search is reported for Higgs boson decay to μ+μ−μ+μ− using data with an integrated luminosity of 24.8 fb−124.8 fb−¹ collected with the ATLAS detector in pp collisions at √s=7 and 8 TeV at the CERN Large Hadron Collider. The observed dimuon invariant mass distribution is consistent with the Standard Model background-only hypothesis in the 120–150 GeV search range. For a Higgs boson with a mass of 125.5 GeV, the observed (expected) upper limit at the 95% confidence level is 7.0 (7.2) times the Standard Model expectation. This corresponds to an upper limit on the branching ratio BR(H→μ+μ−)of 1.5×10−31.5×10−3

    ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider

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    This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton-proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 fb1^{-1} of collisions at a centre-of-mass energy of s\sqrt{s} = 8 TeV, although in some case an additional 4.7 fb1^{-1} of collision data at s\sqrt{s} = 7 TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space. Since no evidence of third-generation squarks is found, exclusion limits are derived by combining several analyses and are presented in both a simplified model framework, assuming simple decay chains, as well as within the context of more elaborate phenomenological supersymmetric models.Comment: 53 pages plus author list + cover page (70 pages total), 24 figures, 10 tables, submitted to Eur. Phys. J., All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2014-07

    Search for direct top squark pair production in final states with two leptons in √s=13 TeV pp collisions with the ATLAS detector

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    The results of a search for direct pair production of top squarks in events with two opposite-charge leptons (electrons or muons) are reported, using 36.1 fb−1 of integrated luminosity from proton–proton collisions at √s=13 TeV collected by the ATLAS detector at the Large Hadron Collider. To cover a range of mass differences between the top squark t~ and lighter supersymmetric particles, four possible decay modes of the top squark are targeted with dedicated selections: the decay t~→bχ~1± into a b-quark and the lightest chargino with χ~1±→Wχ~10 , t~→tχ~10 into an on-shell top quark and the lightest neutralino, the three-body decay t~→bWχ~10 and the four-body decay t~→bℓνχ~10. No significant excess of events is observed above the Standard Model background for any selection, and limits on top squarks are set as a function of the t~ and χ~01 masses. The results exclude at 95% confidence level t~ masses up to about 720 GeV, extending the exclusion region of supersymmetric parameter space covered by previous searches

    Search for new phenomena in events with three or more charged leptons in pppp collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    A generic search for anomalous production of events with at least three charged leptons is presented. The data sample consists of pppp collisions at s=8\sqrt{s}=8 TeV collected in 2012 by the ATLAS experiment at the CERN Large Hadron Collider, and corresponds to an integrated luminosity of 20.3 fb1^{-1}. Events are required to have at least three selected lepton candidates, at least two of which must be electrons or muons, while the third may be a hadronically decaying tau. Selected events are categorized based on their lepton flavour content and signal regions are constructed using several kinematic variables of interest. No significant deviations from Standard Model predictions are observed. Model-independent upper limits on contributions from beyond the Standard Model phenomena are provided for each signal region, along with prescription to re-interpret the limits for any model. Constraints are also placed on models predicting doubly charged Higgs bosons and excited leptons. For doubly charged Higgs bosons decaying to eτe\tau or μτ\mu\tau, lower limits on the mass are set at 400 GeV at 95% confidence level. For excited leptons, constraints are provided as functions of both the mass of the excited state and the compositeness scale Λ\Lambda, with the strongest mass constraints arising in regions where the mass equals Λ\Lambda. In such scenarios, lower mass limits are set at 3.0 TeV for excited electrons and muons, 2.5 TeV for excited taus, and 1.6 TeV for every excited-neutrino flavour.Comment: 442 pages plus author list + cover pages (60 pages total), 6 figures, 25 tables, submitted to JHEP, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2012-20

    Plan integral de salud para alumnos con necesidades educativas especiales

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    Incluye materiales elaborados.Se trata de desarrollar la educación para la salud con programas específicos adaptados a las posibilidades de los alumnos. Los objetivos son conocer el estado de salud de los alumnos; proporcionar información y formación sanitaria a profesores y padres; ayudar al desarrollo curricular de la educación para la salud; lograr colaboración, comunicación e intercambio entre los distintos profesionales del centro y las entidades sanitarias; y fomentar la adquisición de actitudes, conocimientos y hábitos saludables. Se evalúan las actividades y materiales; la participación de profesionales y alumnos; la asimilación, satisfacción y mejora en la autonomía del alumno; y la incidencia en el centro y en las familias..Madrid (Comunidad Autónoma). Consejería de SanidadMadridNo disponibleES

    Aprendiendo clic a clic : educación especial

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    Con el proyecto se quiere elaborar materiales de apoyo, en soporte informático, adaptados a las características del alumnado de educación especial. Los objetivos son crear rincones informáticos; aportar unos instrumentos que posibiliten al profesorado ampliar su formación en las nuevas tecnologías; y ofrecer a los alumnos nuevas vías para la estimulación y el desarrollo cognitivo. Primero el profesorado se familiariza con el uso de Windows para después diseñar actividades como rompecabezas gráficos y de texto, crucigramas, sopas de letras y asociaciones sobre temas comunes de Lengua y Matemáticas. Por último se presentan y aplican las actividades a un grupo de alumnos manteniendo otro de control para medir la eficacia de los materiales: Nuestros amigos los animales y, Verano. Se evalúa el desarrollo personal del alumno, los materiales elaborados y su adecuación, la metodología, su repercusión en el aula y la consecución de los objetivos. Cabe destacar que el proyecto permitió al profesorado adquirir conocimientos básicos de informática, la utilización de un instrumento motivador y útil para preparar actividades y potenció el trabajo en equipo.Madrid (Comunidad Autónoma). Consejería de EducaciónMadridMadrid (Comunidad Autónoma). Subdirección General de Formación del Profesorado. CRIF Las Acacias; General Ricardos 179 - 28025 Madrid; Tel. + 34915250893ES
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