6,694 research outputs found

    Search for new physics with neutrinos at Radioactive Ion Beam facilities

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    We propose applications of Radioactive Ion Beam facilities to investigate physics beyond the Standard Model. In particular, we focus on the possible measurement of coherent neutrino-nucleus scattering and on a search for sterile neutrinos, by means of a low energy beta-beam with a Lorentz boost factor γ1\gamma \approx 1. In the considered setup the collected radioactive ions are sent inside a 4π\pi detector. For the first application we provide the number of events associated with neutrino-nucleus coherent scattering, when the detector is filled in with a noble liquid. For the sterile search we consider that the spherical detector is filled in with a liquid scintillator, and that the neutrino detection channel is inverse-beta decay. We provide the exclusion curves for the sterile neutrino mixing parameters, based upon the 3+1 formalism, depending upon the achievable ion intensity. Our results are obtained both from total rates, and including spectral information with binning in energy and in distance. The proposed experiment represents a possible alternative to clarify the current anomalies observed in neutrino experiments.Comment: 9 pages, 6 figures. v2 - added 2 figure

    Ermakov Systems with Multiplicative Noise

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    Using the Euler-Maruyama numerical method, we present calculations of the Ermakov-Lewis invariant and the dynamic, geometric, and total phases for several cases of stochastic parametric oscillators, including the simplest case of the stochastic harmonic oscillator. The results are compared with the corresponding numerical noiseless cases to evaluate the effect of the noise. Besides, the noiseless cases are analytic and their analytic solutions are briefly presented. The Ermakov-Lewis invariant is not affected by the multiplicative noise in the three particular examples presented in this work, whereas there is a shift effect in the case of the phasesComment: 12 pages, 4 figures, 22 reference

    LabelTranslator: A Tool to Automatically Localize an Ontology

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    This demo proposal briefly presents LabelTranslator, a system that suggests translations of ontology labels, with the purpose of localizing ontologies. LabelTranslator takes as input an ontology whose labels are described in a source natural language and obtains the most probable translation of each ontology label into a target natural language.Our main contribution is the automatization of this process, which reduces human efforts to localize manually the ontology

    New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools: II. SDSS DR7 vs UKIDSS LAS DR6, SDSS DR7 vs UKIDSS LAS DR8, SDSS DR9 vs UKIDSS LAS DR10, and SDSS DR7 vs 2MASS

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    We aim at developing an efficient method to search for late-type subdwarfs (metal-depleted dwarfs with spectral types >M5) to improve the current statistics. Our objectives are: improve our knowledge of metal-poor low-mass dwarfs, bridge the gap between the late-M and L types, determine their surface density, and understand the impact of metallicity on the stellar and substellar mass function. We carried out a search cross-matching the SDSS, 2MASS, and UKIDSS using STILTS, Aladin, and Topcat. We considered different photometric and proper motion criteria for our selection. We identified 29 and 71 late-type subdwarf candidates in each cross-correlation over 8826 and 3679 square degrees, respectively. We obtained low-resolution optical spectra for 71 of our candidates with GTC, NOT, and VLT and retrieved spectra for 30 candidates from the SDSS spectroscopic database. We classified 92 candidates based on 101 optical spectra using two methods: spectral indices and comparison with templates of known subdwarfs. We confirmed 86% and 94% of the candidates as late-type subdwarfs from the SDSS vs 2MASS and SDSS vs UKIDSS cross-matches, respectively. These subdwarfs have spectral types ranging between M5 and L0.5 and SDSS magnitudes in the r=19.4-23.3 mag range. Our new late-type M discoveries include 49 subdwarfs, 25 extreme subdwarfs, six ultrasubdwarfs, one subdwarf/extreme subdwarf, and two dwarfs/subdwarfs. We derived a surface density of late-type subdwarfs of 0.0400.007+0.012^{+0.012}_{-0.007} per square degree in the SDSS DR7 vs UKIDSS LAS DR10 cross-match. We also checked the AllWISE photometry of known and new subdwarfs and found that mid-infrared colours of M subdwarfs do not appear to differ from their solar-metallicity counterparts of similar spectral types. However, the J-W2 and J-W1 colours are bluer for lower metallicity dwarfs. (abstract strongly abridged)Comment: 28 pages, 4 Tables, 10 figures, 1 appendix. Accepted to A&A. Photometry and spectra available in a dedicated archive on late-type subdwarfs at http://svo2.cab.inta-csic.es/vocats/ltsa

    Detection of magnetic moment in thin films with a home-made vibrating sample magnetometer

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    This paper explores the optimization of an array of pick-up coils in a home-made vibrating sample magnetometer for the detection of magnetic moment in thin films. Sensitivity function of a 4-coils Mallinson configuration was numerically studied for the determination of the physical dimensions that enhance the sensitivity of the magnetometer. By performing numerical simulations using the Biot-Savart law combined with the principle of reciprocity we were able to determine the maximum values of sensitivity and the influence of the separation of the coils on the sensitivity function. After the optimization of the pick-up coils, the vibrating sample magnetometer was able to detect the magnetic moment of a 100 nm-thickness Fe19Ni81 magnetic thin film along and perpendicular to the in-plane anisotropy easy axis. The implemented vibrating sample magnetometer is able to detect changes in the magnetic moment of ∼2 × 10-4 emu.Fil: Jordán, D.. Universidad Nacional de Ingeniería. Facultad de Ciencias; PerúFil: González Chávez, D.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Laura, D.. Universidad Nacional de Ingeniería. Facultad de Ciencias; PerúFil: Leon Hilario, Ludwin Misael. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Ingeniería. Facultad de Ciencias; PerúFil: Monteblanco, E.. Universite de Lorraine; FranciaFil: Gutarra Espinoza, Abel. Universidad Nacional de Ingeniería. Facultad de Ciencias; PerúFil: Aviles Felix, Luis Steven. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Aplicación web con énfasis multimedia para divulgar los principales sitios turísticos, promovidos por INTUR en el municipio de Matagalpa, año 2013

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    El Instituto Nicaragüense de Turismo INTUR-Matagalpa, se enfoca en la divulgación y promoción de los sitios turísticos más importantes del municipio, actualmente la información recolectada y los destinos turísticos inscritos se manejan de forma escrita, presentando problemas al momento de brindar información; en cuanto a la divulgación se ha hecho de manera tradicional. Por lo tanto surgió la necesidad de evaluar el proceso de divulgación de los principales sitios turísticos de este municipio, con el fin de detectar las dificultades y así brindar alternativas de solución que puedan ser accesibles y las puedan implementar, para que el instituto nicaragüense de turismo en Matagalpa lleve un control más óptimo de dichos procesos. Además la importancia de proponer una aplicación web con énfasis multimedia, radica que a través de ella se podrá presentar o comunicar información de una forma original y llamativa, añadiendo gráficos, textos, imágenes, animaciones, sonido, tours virtuales, visitas previas a los sitios, videos, entre otros, permitiendo que los turistas tanto nacionales como extranjeros puedan elegir entre las vistas propuestas presentadas a través de la aplicación web. En el proceso de divulgación de los principales sitios turísticos se utilizan los medios electrónicos, audiovisuales e impresos, las dificultades encontradas en este proceso de divulgación son: Ausencia de presupuesto, Falta de capacitación del personal, Ausencia de una página web y además ineficiencia de la comunicación de información al momento de promover dichos sitios turísticos y se logró desarrollar una aplicación web con énfasis multimedia, que dará solución a dichas dificultades encontrada

    A two-temperature open-source CFD model for hypersonic reacting flows, part two : multi-dimensional analysis

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    hy2Foam is a newly-coded open-source two-temperature computational fluid dynamics (CFD) solver that has previously been validated for zero-dimensional test cases. It aims at (1) giving open-source access to a state-of-the-art hypersonic CFD solver to students and researchers; and (2) providing a foundation for a future hybrid CFD-DSMC (direct simulation Monte Carlo) code within the OpenFOAM framework. This paper focuses on the multi-dimensional verification of hy2Foam and firstly describes the different models implemented. In conjunction with employing the coupled vibration-dissociation-vibration (CVDV) chemistry–vibration model, novel use is made of the quantum-kinetic (QK) rates in a CFD solver. hy2Foam has been shown to produce results in good agreement with previously published data for a Mach 11 nitrogen flow over a blunted cone and with the dsmcFoam code for a Mach 20 cylinder flow for a binary reacting mixture. This latter case scenario provides a useful basis for other codes to compare against
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