4,441 research outputs found

    Hydroxyapatite thick films as pressure sensors

    Get PDF
    Electrical properties of hydroxyapatite (HA) in the form of screen printed thick films that can be used as a biocompatible coating for bone and dental implants are reported. In particular, piezo- and pyroelectric behaviour of these films suggest that they can be used to promote faster healing of bones and prevent rejection of implants. Moreover, the reversible pressure-induced changes in their electrical characteristics can be employed for real-time in vivo pressure sensors implantable simultaneously, for example, with knee or hip prosthesis. The additional advantage of HA in the form of screen-printed thick films is that, due to the technology’s versatility, it can be produced on flexible substrate in any shape and size to suit the needs of various patients

    A hexagon based Mn(ii) rod metal-organic framework - structure, SF6 gas sorption, magnetism and electrochemistry

    Get PDF
    A manganese(ii) metal-organic framework based on the hexatopic hexakis(4-carboxyphenyl)benzene, cpb6−: [Mn3(cpb)(dmf)3], was solvothermally prepared showing a Langmuir area of 438 m2 g−1, rapid uptake of sulfur hexafluoride (SF6) as well as electrochemical and magnetic properties, while single crystal diffraction reveals an unusual rod-MOF topology

    The Large Aperture GRB Observatory

    Full text link
    The Large Aperture GRB Observatory (LAGO) is aiming at the detection of the high energy (around 100 GeV) component of Gamma Ray Bursts, using the single particle technique in arrays of Water Cherenkov Detectors (WCD) in high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). WCD at high altitude offer a unique possibility of detecting low gamma fluxes in the 10 GeV - 1 TeV range. The status of the Observatory and data collected from 2007 to date will be presented.Comment: 4 pages, proceeding of 31st ICRC 200

    Water Cherenkov Detectors response to a Gamma Ray Burst in the Large Aperture GRB Observatory

    Full text link
    In order to characterise the behaviour of Water Cherenkov Detectors (WCD) under a sudden increase of 1 GeV - 1 TeV background photons from a Gamma Ray Burst (GRB), simulations were conducted and compared to data acquired by the WCD of the Large Aperture GRB Observatory (LAGO). The LAGO operates arrays of WCD at high altitude to detect GRBs using the single particle technique. The LAGO sensitivity to GRBs is derived from the reported simulations of the gamma initiated particle showers in the atmosphere and the WCD response to secondaries.Comment: 5 pages, proceeding of the 31st ICRC 200

    Use of water-Cherenkov detectors to detect Gamma-Ray-Bursts at the Large Aperture GRB Observatory (LAGO)

    Get PDF
    The Large Aperture GRB Observatory (LAGO) project aims at the detection of high energy photons from Gamma Ray Bursts (GRB) using the single particle technique in ground-based water-Cherenkov detectors (WCD). To reach a reasonable sensitivity, high altitude mountain sites have been selected in Mexico (Sierra Negra, 4550 m a.s.l.), Bolivia (Chacaltaya, 5300 m a.s.l.) and Venezuela (Me´ rida, 4765 m a.s.l.). We report on detector calibration and operation at high altitude, search for bursts in 4 months of preliminary data, as well as search for signal at ground level when satellites report a burst.Fil: Allard, D.. Université Paris Diderot - Paris 7; FranciaFil: Allekotte, Ingomar. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Alvarez, C.. Facultad de Ciencias Fısico-Matematicas; MéxicoFil: Asorey, Hernán Gonzalo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Barros, H.. Universidad Simon Bolivar; VenezuelaFil: Bertou, Xavier Pierre Louis. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Burgoa, O.. Instituto de Investigaciones Fisicas; BoliviaFil: Gomez Berisso, Mariano. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Martinez, O.. Facultad de Ciencias Fısico-Matematicas; MéxicoFil: Miranda Loza, P.. Instituto de Investigaciones Fısicas; BoliviaFil: Murrieta, T.. Facultad de Ciencias Fısico-Matematicas; MéxicoFil: Perez, G.. Facultad de Ciencias Fısico-Matematicas; MéxicoFil: Rivera, H.. Instituto de Investigaciones Fısicas; BoliviaFil: Rovero, Adrian Carlos. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Saavedra, O.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Salazar, H.. Facultad de Ciencias Fısico-Matematicas ; MéxicoFil: Tello, J. C.. Universidad Simon Bolıvar; VenezuelaFil: Ticona Peralda, R.. Instituto de Investigaciones Fısicas; BoliviaFil: Velarde, A.. Instituto de Investigaciones Fısicas; BoliviaFil: Villaseñor, L.. Universidad de Michoacan; MéxicoFil: Areso, Omar Antonio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Arnaldi, Luis Horacio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Dasso, Sergio Ricardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Gonzalez, M.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Gulisano, Adriana Maria. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Martin, R.. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Masías Meza, Jimmy Joel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Sidelnik, Iván Pedro. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Alvarez, W.. Universidad de San Carlos; GuatemalaFil: The LAGO Collaboration

    The 2HWC HAWC Observatory Gamma Ray Catalog

    Full text link
    We present the first catalog of TeV gamma-ray sources realized with the recently completed High Altitude Water Cherenkov Observatory (HAWC). It is the most sensitive wide field-of-view TeV telescope currently in operation, with a 1-year survey sensitivity of ~5-10% of the flux of the Crab Nebula. With an instantaneous field of view >1.5 sr and >90% duty cycle, it continuously surveys and monitors the sky for gamma ray energies between hundreds GeV and tens of TeV. HAWC is located in Mexico at a latitude of 19 degree North and was completed in March 2015. Here, we present the 2HWC catalog, which is the result of the first source search realized with the complete HAWC detector. Realized with 507 days of data and represents the most sensitive TeV survey to date for such a large fraction of the sky. A total of 39 sources were detected, with an expected contamination of 0.5 due to background fluctuation. Out of these sources, 16 are more than one degree away from any previously reported TeV source. The source list, including the position measurement, spectrum measurement, and uncertainties, is reported. Seven of the detected sources may be associated with pulsar wind nebulae, two with supernova remnants, two with blazars, and the remaining 23 have no firm identification yet.Comment: Submitted 2017/02/09 to the Astrophysical Journa
    • …
    corecore