1,003 research outputs found

    In-situ Micro-Raman spectroscopic analysis of Handprints in Maltravieso Cave (Cáceres), Spain

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    TECHNART 2015 − Catania, April 27 - 30, 2015; http://technart2015.lns.infn.it/Peer Reviewe

    Cientópolis: motorizando la ciencia ciudadana

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    En ciertas situaciones como la toma, clasificación y etiquetado de muestras, el científico realiza un gran número de tareas simples, repetitivas, que no pueden ser automatizadas y que podrían ser ejecutadas por personas sin formación en la materia si se las entrena y asiste con herramientas. En el pasado, en proyectos de conservación, astronomía y biología, entre otros, este tipo de tareas se ha delegado de manera efectiva a voluntarios. Cuando se convoca a ciudadanos voluntarios para colaborar con los científicos, se habla de ciencia ciudadana. Encontrar e involucrar a esos voluntarios, sumado a coordinar y reconocer su trabajo, es una tarea compleja. Definir y conducir proyectos de ciencia ciudadana presenta desafíos en tres áreas críticas: metodologías, tecnologías y construcción de comunidades de voluntarios. El proyecto Cientópolis (http://cientopolis.org) tiene como objetivo producir avances en estas tres áreas y socializarlos con la comunidad. En la actualidad, Cientópolis brinda espacios para compartir conocimiento y experiencias, ofrece herramientas para la construcción de proyectos de toma de muestras con dispositivos móviles y construcción colaborativa de conocimiento, da acceso a una comunidad creciente de ciudadanos científicos y explora estrategias de ludificación para consolidar y sostener dicha comunidad.Trabajo presentado por el Laboratorio de Investigación y Formación en Informática Avanzada (LIFIA

    The Solar Twin Planet Search: The age-chromospheric activity relation

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    Context. It is well known that the magnetic activity of solar-type stars decreases with age, but it is widely debated in the literature whether there is a smooth decline or if there is an early sharp drop until 1-2 Gyr that is followed by a relatively inactive constant phase. Aims. We revisited the activity-age relation using time-series observations of a large sample of solar twins whose precise isochronal ages and other important physical parameters have been determined. Methods. We measured the Ca II H and K activity indices using ≈ 9000 HARPS spectra of 82 solar twins. In addition, the average solar activity was calculated through asteroids and Moon reflection spectra using the same instrumentation. Thus, we transformed our activity indices into the S Mount Wilson scale (SMW), recalibrated the Mount Wilson absolute flux and photospheric correction equations as a function of Teff, and then computed an improved bolometric flux normalized activity index log R′HK (Teff) for the entire sample. Results. New relations between activity and the age of solar twins were derived by assessing the chromospheric age-dating limits using log R′HK (Teff). We measured an average solar activity of SMW = 0.1712 ± 0.0017 during solar magnetic cycles 23-24 covered by HARPS observations, and we also inferred an average of SMW = 0.1694 ± 0.0025 for cycles 10-24, anchored on a sunspot number correlation of S index versus. We also found a simple relation between the average and the dispersion of the activity levels of solar twins. This enabled us to predict the stellar variability effects on the age-activity diagram, and consequently, to estimate the chromospheric age uncertainties that are due to the same phenomena. The age-activity relation is still statistically significant up to ages around 6-7 Gyr, in agreement with previous works using open clusters and field stars with precise ages. Conclusions. Our research confirms that Ca II H & K lines remain a useful chromospheric evolution tracer until stars reach ages of at least 6-7 Gyr. We found evidence that for the most homogenous set of old stars, the chromospheric activity indices seem to continue to decrease after the solar age toward the end of the main sequence. Our results indicate that a significant part of the scatter observed in the age-activity relation of solar twins can be attributed to stellar cycle modulations effects. The Sun seems to have a normal activity level and variability for its age.DLO acknowledges the support from FAPESP (2016/20667-8). JM acknowledges support from FAPESP (2012/24392-2) and CNPq (Productivity Fellowship)

    Edad y provenincia de las rocas volcánico sedimentarias de la formación combia en el suroccidente antioqueño colombia

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    Los estudios petrográficos y de paleocorrientes realizados en la Formación Combia (Mioceno), departamentos de Antioquia y Caldas en Colombia sugieren que ésta se formó a partir flujos volcánicos y volcanicoclásticos que se originaron hacia el oeste y este del actual Valle del Río Cauca.Los estudios de trazas de fisión en circones colectados de diferentes horizontes de la Formación Combia arrojan edades Cretácicas, Paleoceno Tardío EocenoTemprano y Mioceno Tardío, las cuales han sido interpretadas como el resultadode eventos sintectónicos generados a lo largo del Sistema de Fallas Romeral, en los que se dio el retrabajamiento del basamento cretácico y del Miembro inferior de la Formación Amagá, coetáneamente con los eventos volcánicos, entre 10 y 6 Ma, que dieron origen a la Formación Combia.Dentro de las edades obtenidas se destaca la de 53,4 ± 1,4 Ma en una muestra de ceniza de caída que no presenta retrabajamiento alguno. Este resultado sugiere que los sedimentos subyacentes serían aún más antiguos y en consecuencia, que el volcanismo tipo Combia pudo haber comenzado en el Paleoceno y no en el Mioceno como ha sido hasta el momento aceptado

    Determining the neutrino mass ordering and oscillation parameters with KM3NeT/ORCA

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    [EN] The next generation of water Cherenkov neu-trino telescopes in the Mediterranean Sea are under con- struction offshore France (KM3NeT/ORCA) and Sicily (KM3NeT/ARCA). The KM3NeT/ORCA detector features an energy detection threshold which allows to collect atmo- spheric neutrinos to study flavour oscillation. This paper reports the KM3NeT/ORCA sensitivity to this phenomenon. The event reconstruction, selection and classification are described. The sensitivity to determine the neutrino mass ordering was evaluated and found to be 4.4¿ if the true order- ing is normal and 2.3¿ if inverted, after 3 years of data taking. The precision to measure ¿m² and ¿¿¿ were also estimated and found to be 85.10¿¿ eV² and (¿¹.¿ -3.1)¿ for normal neu- trino mass ordering and, 75.10¿¿ eV² and (¿².¿ -7.0)¿ for inverted ordering. Finally, a unitarity test of the leptonic mixing matrix by measuring the rate of tau neutrinos is described. Three years of data taking were found to be sufficient to exclude ¿The authors acknowledge the financial support of the funding agencies: Agence Nationale de la Recherche (contract ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Paris Ile-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Universita e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education Scientific Research and Professional Training, ICTP through Grant AF-13, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Junta de Andalucia (ref. SOMM17/6104/UGR), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119) and GenT (ref. CIDEGENT/2018/034 and CIDEGENT/2019/043) programs, La Caixa Foundation (ref. LCF/BQ/IN17/11620019), EU: MSC program (ref. 713673), Spain.Aiello, S.; Albert, A.; Alves Garre, S.; Aly, Z.; Ambrosone, A.; Ameli, F.; Andre, M.... (2022). Determining the neutrino mass ordering and oscillation parameters with KM3NeT/ORCA. The European Physical Journal C. 82(1):1-16. https://doi.org/10.1140/epjc/s10052-021-09893-011682

    Sensitivity to light sterile neutrino mixing parameters with KM3NeT/ORCA

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    [EN] KM3NeT/ORCA is a next-generation neutrino telescope optimised for atmospheric neutrino oscillations studies. In this paper, the sensitivity of ORCA to the presence of a light sterile neutrino in a 3+1 model is presented. After three years of data taking, ORCA will be able to probe the active-sterile mixing angles ¿¿¿, ¿¿¿, ¿¿¿ and the effective angle ¿µ¿, over a broad range of mass squared difference ¿m² ~ [10¿5, 10] eV2, allowing to test the eV-mass sterile neutrino hypothesis as the origin of short baseline anomalies, as well as probing the hypothesis of a very light sterile neutrino, not yet constrained by cosmology. ORCA will be able to explore a relevant fraction of the parameter space not yet reached by present measurements.The authors acknowledge the financial support of the funding agencies: Agence Nationale de la Recherche (contract ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Paris Ile-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Universita e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education Scientific Research and Professional Training, ICTP through Grant AF-13, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Generalitat Valenciana: Prometeo (PROMETEO/2020/019), Grisolia (ref. GRISOLIA/2018/119) and GenT (refs. CIDEGENT/2018/034,/2019/043,/2020/049) programs, Junta de Andalucia (ref. A-FQM-053-UGR18), La Caixa Foundation (ref. LCF/BQ/IN17/11620019), EU: MSC program (ref. 101025085), Spain.Aiello, S.; Albert, A.; Alshamsi, M.; Alves Garre, S.; Aly, Z.; Ambrosone, A.; Ameli, F.... (2021). Sensitivity to light sterile neutrino mixing parameters with KM3NeT/ORCA. Journal of High Energy Physics (Online). 10:1-22. https://doi.org/10.1007/JHEP10(2021)1801221

    Implementation and first results of the KM3NeT real-time core-collapse supernova neutrino search

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    [EN] The KM3NeT research infrastructure is uncon- struction in the Mediterranean Sea. KM3NeT will study atmospheric and astrophysical neutrinos with two multi- purpose neutrino detectors, ARCA and ORCA, primar-ily aimed at GeV¿PeV neutrinos. Thanks to the multi-photomultiplier tube design of the digital optical modules, KM3NeT is capable of detecting the neutrino burst from a Galactic or near-Galactic core-collapse supernova. This potential is already exploitable with the first detection units deployed in the sea. This paper describes the real-time imple- mentation of the supernova neutrino search, operating on the two KM3NeT detectors since the first months of 2019. A quasi-online astronomy analysis is introduced to study the time profile of the detected neutrinos for especially signifi- cant events. The mechanism of generation and distribution of alerts, as well as the integration into the SNEWS and SNEWS 2.0 global alert systems, are described. The approach for the follow-up of external alerts with a search for a neutrino excess in the archival data is defined. Finally, an overview of the cur-rent detector capabilities and a report after the first two years of operation are given.The authors acknowledge the financial support of the funding agencies: Agence Nationale de la Recherche (contract ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Paris ile-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Universita e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education Scientific Research and Professional Training, ICTP through Grant AF-13, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Generalitat Valenciana: Prometeo (PROMETEO/2020/019), Grisolia (ref. GRISOLIA/2018/119) and GenT (refs. CIDEGENT/2018/034, /2019/043, /2020/049) programs, Junta de Andalucia (ref. A-FQM-053-UGR18), La Caixa Foundation (ref. LCF/BQ/IN17/11620019), EU: MSC program (ref. 101025085), Spain.Aiello, S.; Albert, A.; Alshamsi, M.; Alves Garre, S.; Aly, Z.; Ambrosone, A.; Ameli, F.... (2022). Implementation and first results of the KM3NeT real-time core-collapse supernova neutrino search. The European Physical Journal C. 82(4):1-16. https://doi.org/10.1140/epjc/s10052-022-10137-y11682

    Nanobeacon: A time calibration device for the KM3NeT neutrino telescope

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    [EN] The KM3NeT Collaboration is currently constructing a multi-site high-energy neutrino telescope in the Mediterranean Sea consisting of matrices of pressure-resistant glass spheres, each holding a set of 31 small-area photomultipliers. The main goals of the telescope are the observation of neutrino sources in the Universe and the measurement of the neutrino oscillation parameters with atmospheric neutrinos. A relative time synchronisation between photomultipliers of the nanosecond arder needed to guarantee the required angular resolution of the detector. Due to the large detector volumes to be instrumented by KM3NeT, a cost reduction of the different systems is a priority. To this end, the inexpensive Nanobeacon has been designed and developed by the KM3NeT Collaboration to be used for detector time-calibration studies. At present, more than 600 Nanobeacons have been already produced. The characterisation of the optical pulse and the wavelength emission profile of the devices is critica! for the time calibration. The optical pulse rise time has been quantified as less than 3 ns, while the Full Width Half Maximum is less than 6 ns. The wavelength drift, due to a variation of the supply voltage, has also been qualified as lower than 10 nm for the full range of the Nanobeacon. In this paper, more details about the main features of the Nanobeacon design, production and operation, together with the main properties of the light pulse generated are described.The authors acknowledge the financial support of the funding agencies: Agence Nationale de la Recherche (contract ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Paris Ile-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Universita e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education Scientific Research and Professional Training, ICTP through Grant AF-13, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia, Innovacion, Investigacion.. Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Generalitat Valenciana: Prometeo (PROMETEO/2020/019), Grisolia (ref. GRISOLIA/2018/119) and GenT (refs. CIDEGENT/2018/034,/2019/043,/2020/049) programs, Junta de Andalucia (ref. A-FQM-053-UGR18), La Caixa Foundation (ref. LCF/BQ/IN17/11620019), EU: MSC program (ref. 101025085), Spain.Aiello, S.; Albert, A.; Alshamsi, M.; Alves Garre, S.; Aly, Z.; Ambrosone, A.; Ameli, F.... (2022). Nanobeacon: A time calibration device for the KM3NeT neutrino telescope. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 1040:1-13. https://doi.org/10.1016/j.nima.2022.167132113104

    The KM3NeT multi-PMT optical module

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    [EN] The optical module of the KM3NeT neutrino telescope is an innovative multi-faceted large area photodetection module. It contains 31 three-inch photomultiplier tubes in a single 0.44 m diameter pressure-resistant glass sphere. The module is a sensory device also comprising calibration instruments and electronics for power, readout and data acquisition. It is capped with a breakout-box with electronics for connection to an electro-optical cable for power and long-distance communication to the onshore control station. The design of the module was qualified for the first time in the deep sea in 2013. Since then, the technology has been further improved to meet requirements of scalability, cost-effectiveness and high reliability. The module features a sub-nanosecond timing accuracy and a dynamic range allowing the measurement of a single photon up to a cascade of thousands of photons, suited for the measurement of the Cherenkov radiation induced in water by secondary particles from interactions of neutrinos with energies in the range of GeV to PeV. A distributed production model has been implemented for the delivery of more than 6000 modules in the coming few years with an average production rate of more than 100 modules per month. In this paper a review is presented of the design of the multi-PMT KM3NeT optical module with a proven effective background suppression and signal recognition and sensitivity to the incoming direction of photons.The authors acknowledge the financial support of the funding agencies: Agence Nationale de la Recherche (contract ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Européenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Paris Île-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, FR-18- 1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell¿Università e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education, Scientific Research and Innovation, Morocco, and the Arab Fund for Economic and Social Development, Kuwait; Nederlandse organisatie voor Wetenschappel¿k Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia, Innovación, Investigación y Universidades (MCIU): Programa Estatal de Generación de Conocimiento (refs. PGC2018-096663- B-C41,-A C42,-B-C43,-B-C44) (MCIU/FEDER), Generalitat Valenciana: Prometeo (PROMETEO/2020/019), Grisolía (refs. GRISOLIA/2018/119,/2021/192) and GenT (refs. CIDEGENT/2018/034, /2019/043,/2020/049,/2021/023) programs, Junta de Andalucía (ref. AFQM-053-UGR18), La Caixa Foundation (ref. LCF/BQ/IN17/11620019), EU: MSC program (ref. 101025085), Spain.Aiello, S.; Albert, A.; Alshamsi, M.; Alves Garre, S.; Aly, Z.; Ambrosone, A.; Ameli, F.... (2022). The KM3NeT multi-PMT optical module. Journal of Instrumentation. 17:1-23. https://doi.org/10.1088/1748-0221/17/07/P070381231
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