627 research outputs found

    Vision Sidéreo system.

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    Este proyecto tiene la finalidad de generar energía limpia mediante el sol, lo innovador de este proyecto es que el panel no estará estático, sino que el panel solar girara conforme gire el sol, esto para aprovechar a un 100% la energía solar y no solo a medias como sucede con los paneles tradicionales. Dicho giro se realizara mediante la hora del día la cual será la encargada de buscar el ángulo en que está posicionado el sol con la tierra y estas mandaran la información al Arduino que a su vez se la mandara al servomotor (previamente programado) el cual está encargado de realizar los giros por ángulos. Ya encontrado el ángulo del sol y que el panel este en posición este empezara a generar la energía la cual entra a un controlador de carga el cual mantendrá la energía en 12V DC, la cual ira a un acumulador, que en este caso será una batería de carro, que está conectado a un inversor de voltaje para que la salida nos la arroje a 110V AC y se pueda utilizar en casa sin ningún problema

    Adaptación de líneas experimentales de frijol tipo negro y pinto en el altiplano semiárido de México

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    En el altiplano semiárido de México el temporal lluvias normalmente se inicia durante los primeros dias de julio y termina en septiembre. La precipitación durante el ciclo de cultivo es escasa y su distribución es errática, lo que provoca la ocurrencia de períodos de estrés hidrico que reducen el rendimiento de grano hasta en 60%. Para incrementar y estabilizar los rendimientos de frijol en la zona, se requieren variedades de frijol resistentes a estrés hidrico y a enfermedades como antracnosis, bacteriosis y roya, así como a un complejo de pudriciones de la raíz compuesto por Rhizoctonia, Fusarium y Pythium. Con el objeto de identificar variedades de frijol con adaptación y estabilidad de rendimiento para las condiciones del altiplano semiárido de México se evaluaron en 15 ambientes, durante 1993 y 1994, dos grupos de líneas avanzadas de frijol, uno de tipo negro y otro de tipo pinto. Se llevaron a cabo los análisis de varianza individuales y en conjunto (localidades y años) con los datos de rendimiento de grano, fenológicos, la reacción a enfermedades y capacidad de imbibición del grano. Así mismo, se utilizaron dos métodos para estimar la estabilidad de las líneas de frijol evaluadas. Dentro del material tipo negro las líneas NG 91205, NG 91207 y NG 91153 mostraron amplia adaptación, potencial de rendimiento, resistencia a enfermedades y alta permeabilidad de la testa. Entre los pintos, ocho líneas resultaron sobresalientes ya que mostraron menor interacción genotipo x ambiente, de ellas PT 91080, PT 91081, PT 91325 y MX 8385-14M mostraron menor susceptibilidad a sequía. El grupo de líneas de frijol evaluadas permitió cuantificar la adaptación del fríjol a las diferentes condiciones agroclimáticas del altiplano semiárido de México. Este estudio indicó que las variedades de frijol por desarrollar para la región tienen que tener resistencia a múltiples factores bióticos y abióticos, que permitan aumentar y estabilizar los rendimientos de grano

    COVIDiSTRESS diverse dataset on psychological and behavioural outcomes one year into the COVID-19 pandemic

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    During the onset of the COVID-19 pandemic, the COVIDiSTRESS Consortium launched an open-access global survey to understand and improve individuals’ experiences related to the crisis. A year later, we extended this line of research by launching a new survey to address the dynamic landscape of the pandemic. This survey was released with the goal of addressing diversity, equity, and inclusion by working with over 150 researchers across the globe who collected data in 48 languages and dialects across 137 countries. The resulting cleaned dataset described here includes 15,740 of over 20,000 responses. The dataset allows cross-cultural study of psychological wellbeing and behaviours a year into the pandemic. It includes measures of stress, resilience, vaccine attitudes, trust in government and scientists, compliance, and information acquisition and misperceptions regarding COVID-19. Open-access raw and cleaned datasets with computed scores are available. Just as our initial COVIDiSTRESS dataset has facilitated government policy decisions regarding health crises, this dataset can be used by researchers and policy makers to inform research, decisions, and policy.</jats:p

    Combined dark matter searches towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS

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    Cosmological and astrophysical observations suggest that 85\% of the total matter of the Universe is made of Dark Matter (DM). However, its nature remains one of the most challenging and fundamental open questions of particle physics. Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the nature of DM such as Weakly Interacting Massive Particles (WIMPs), the most favored particle candidates. WIMP annihilations and decay could produce SM particles which in turn hadronize and decay to give SM secondaries such as high energy γ\gamma rays. In the framework of indirect DM search, observations of promising targets are used to search for signatures of DM annihilation. Among these, the dwarf spheroidal galaxies (dSphs) are commonly favored owing to their expected high DM content and negligible astrophysical background. In this work, we present the very first combination of 20 dSph observations, performed by the Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS collaborations in order to maximize the sensitivity of DM searches and improve the current results. We use a joint maximum likelihood approach combining each experiment's individual analysis to derive more constraining upper limits on the WIMP DM self-annihilation cross-section as a function of DM particle mass. We present new DM constraints over the widest mass range ever reported, extending from 5 GeV to 100 TeV thanks to the combination of these five different γ\gamma-ray instruments

    Search for a new resonance decaying into two spin-0 bosons in a final state with two photons and two bottom quarks in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceA search for a new boson X is presented using CERN LHC proton-proton collision data collected by the CMS experiment at s\sqrt{s} = 13 TeV in 2016-2018, and corresponding to an integrated luminosity of 138 fb1^{-1}. The resonance X decays into either a pair of Higgs bosons HH of mass 125 GeV or an H and a new spin-0 boson Y. One H subsequently decays to a pair of photons, and the second H or Y, to a pair of bottom quarks. The explored mass ranges of X are 260-1000 GeV and 300-1000 GeV, for decays to HH and to HY, respectively, with the Y mass range being 90-800 GeV. For a spin-0 X hypothesis, the 95% confidence level upper limit on the product of its production cross section and decay branching fraction is observed to be within 0.90-0.04 fb, depending on the masses of X and Y. The largest deviation from the background-only hypothesis with a local (global) significance of 3.8 (2.8) standard deviations is observed for X and Y masses of 650 and 90 GeV, respectively. The limits are interpreted using several models of new physics

    Multiplicity and transverse momentum dependence of charge-balance functions in pPb and PbPb collisions at LHC energies

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    International audienceMeasurements of the charge-dependent two-particle angular correlation function in proton-lead (pPb) collisions at a nucleon-nucleon center-of-mass energy of sNN\sqrt{s_\mathrm{NN}} = 8.16 TeV and lead-lead (PbPb) collisions atsNN\sqrt{s_\mathrm{NN}} = 5.02 TeV are reported. The pPb and PbPb datasets correspond to integrated luminosities of 186\nbinv and 0.607 nb1^{-1}, respectively, and were collected using the CMS detector at the CERN LHC. The charge-dependent correlations are characterized by balance functions of same- and opposite-sign particle pairs. The balance functions, which contain information about the creation time of charged particle pairs and the development of collectivity, are studied as functions of relative pseudorapidity (Δη\Delta \eta) and relative azimuthal angle (Δϕ\Delta \phi), for various multiplicity and transverse momentum (pTp_\mathrm{T}) intervals. A multiplicity dependence of the balance function is observed in Δη\Delta \eta and Δϕ\Delta \phi for both systems. The width of the balance functions decreases towards high-multiplicity collisions in the momentum region <\lt2 GeV, for pPb and PbPb results. No multiplicity dependence is observed at higher transverse momentum. The data are compared with HYDJET, HIJING and AMPT generator predictions, none of which capture completely the multiplicity dependence seen in the data

    Search for resonances in events with photon and jet final states in proton-proton collisions at s\sqrt{s}= 13 TeV

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    International audienceA search for resonances in events with the γ\gamma+jet final state has been performed using proton-proton collision data collected at s\sqrt{s}= 13 TeV by the CMS experiment at the LHC. The total data analyzed correspond to an integrated luminosity of 138 fb1^{-1}. Models of excited quarks and quantum black holes are considered. The invariant mass spectrum of the γ\gamma+jet system is examined for the presence of resonances over the standard model continuum background. The data exhibit no statistically significant deviations from the expected standard model background. Exclusion limits at 95% confidence level on the resonance mass and other parameters are set. Excited light-flavor quarks (excited bottom quarks) are excluded up to a mass of 6.0 (3.8) TeV. Quantum black hole production is excluded for masses up to 7.5 (5.2) TeV in the Arkani-Hamed-Dimopoulos-Dvali (Randall-Sundrum) model. These lower mass bounds are the most stringent to date among those obtained in the γ\gamma+jet final state

    Search for top squark pair production in a final state with at least one hadronically decaying tau lepton in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A search for pair production of the supersymmetric partner of the top quark, the top squark, in proton-proton collisions at s \sqrt{s} = 13 TeV is presented in final states containing at least one hadronically decaying tau lepton and large missing transverse momentum. This final state is highly sensitive to scenarios of supersymmetry in which the decay of the top squark to tau leptons is enhanced. The search uses a data sample corresponding to an integrated luminosity of 138 fb1^{−1}, which was recorded with the CMS detector during 2016–2018. No significant excess is observed with respect to the standard model predictions. Exclusion limits at 95% confidence level on the masses of the top squark and the lightest neutralino are presented under the assumptions of simplified models. The results probe top squark masses up to 1150 GeV for a nearly massless neutralino. This search covers a relatively less explored parameter space in the context of supersymmetry, and the exclusion limit is the most stringent to date for the model considered here.[graphic not available: see fulltext

    Performance of the local reconstruction algorithms for the CMS hadron calorimeter with Run 2 data

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    International audienceA description is presented of the algorithms used to reconstruct energy deposited in the CMS hadron calorimeter during Run 2 (2015-2018) of the LHC. During Run 2, the characteristic bunch-crossing spacing for proton-proton collisions was 25 ns, which resulted in overlapping signals from adjacent crossings. The energy corresponding to a particular bunch crossing of interest is estimated using the known pulse shapes of energy depositions in the calorimeter, which are measured as functions of both energy and time. A variety of algorithms were developed to mitigate the effects of adjacent bunch crossings on local energy reconstruction in the hadron calorimeter in Run 2, and their performance is compared
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