B-LEARNING AND MOODLE AS A STRATEGY IN UNIVERSITY EDUCATION: LATIN AMERICA CASE BY 2017-2022

A documentary review was carried out on the production and publication of research papers concerning studying B-learning, Higher Education, and Moodle as a strategy in university education. The purpose of the bibliometric analysis proposed in this paper was to know the main characteristics of the volume of publications registered in the Scopus database during the period 2017-2022 and to identify the current situation in Ecuadorian institutions regarding the study of the variables mentioned above, achieving the identification of 78 publications in total. The information provided by the said platform was organized employing graphs and figures categorizing the information by Year of Publication, Country of Origin, Area of Knowledge and Type of Publication. Once these characteristics were described, a qualitative analysis was used to refer to the position of different authors on the proposed topic. Among the main findings of this research, it is found that Spain, with 28 publications, was the country with the highest scientific production registered in the name of authors affiliated with institutions of that nation. The area of knowledge that made the greatest contribution to the construction of bibliographic material referring to the study of B-learning, Higher Education, Moodle as a strategy in university education was Social Sciences with 41 published documents, and the type of publication that was most used during the period mentioned above was the journal article, representing 56% of the total scientific production

Preliminary temperature accelerated life test (ALT) on lattice mismatched triple-junction concentrator solar cells-on-carriers

A temperature accelerated life test on concentrator lattice mismatched Ga0.37In0.63P/Ga0.83In0.17As/Ge triple-junction solar cells-on-carrier is being carried out. The solar cells have been tested at three different temperatures: 125, 145 and 165°C and the nominal photo-current condition (500X) is emulated by injecting current in darkness. The final objective of these tests is to evaluate the reliability, warranty period, and failure mechanism of these solar cells in a moderate period of time. Up to now only the test at 165°C has finished. Therefore, we cannot provide complete reliability information, but we have carried out preliminary data and failure analysis with the current results

Gamma-ray observations of MAXI J1820+070 during the 2018 outburst

Artículo firmado por 443 autores. MAGIC acknowledgements: MAGIC would like to thank the Instituto de Astrofisica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF, MPG, and HGF; the Italian INFN and INAF; the Swiss National Fund SNF; the grants PID2019-104114RB-C31, PID2019-104114RB-C32, PID2019-104114RB-C33, PID2019-105510GB-C31, PID2019-107847RB-C41, PID2019-107847RB-C42, PID2019-107847RB-C44, PID2019-107988GB-C22 funded by MCIN/AEI/ 10.13039/501100011033; the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-400/18.12.2020 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also been supported by Centros de Excelencia 'Severo Ochoa' y Unidades 'Maria de Maeztu' program of the MCIN/AEI/ 10.13039/501100011033 (SEV-2016-0588, SEV-2017-0709, CEX2019-000920-S, CEX2019-000918-M, MDM-2015-0509-18-2) and by the CERCA institution of the Generalitat de Catalunya; by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project uniri-prirod-18-48; by the DFG Collaborative Research Centers SFB1491 and SFB876/C3; the Polish Ministry Of Education and Science grant No. 2021/WK/08; and by the Brazilian MCTIC, CNPq and FAPERJ. H.E.S.S. acknowledgements: the support of the Namibian authorities and of the University of Namibia in facilitating the construction and operation of H.E.S.S. is gratefully acknowledged, as is the support by the German Ministry for Education and Research (BMBF), the Max Planck Society, the German Research Foundation (DFG), the Helmholtz Association, the Alexander von Humboldt Foundation, the French Ministry of Higher Education, Research and Innovation, the Centre National de la Recherche Scientifique (CNRS/IN2P3 and CNRS/INSU), the Commissariat a l'energie atomique et aux energies alternatives (CEA), the U.K. Science and Technology Facilities Council (STFC), the Irish Research Council (IRC) and the Science Foundation Ireland (SFI), the Knut and Alice Wallenberg Foundation, the Polish Ministry of Education and Science, agreement no. 2021/WK/06, the South African Department of Science and Technology and National Research Foundation, the University of Namibia, the National Commission on Research, Science & Technology of Namibia (NCRST), the Austrian Federal Ministry of Education, Science and Research and the Austrian Science Fund (FWF), the Australian Research Council (ARC), the Japan Society for the Promotion of Science, the University of Amsterdam and the Science Committee of Armenia grant 21AG-1C085. We appreciate the excellent work of the technical support staff in Berlin, Zeuthen, Heidelberg, Palaiseau, Paris, Saclay, Tubingen and in Namibia in the construction and operation of the equipment. This work benefited from services provided by the H.E.S.S. Virtual Organisation, supported by the national resource providers of the EGI Federation. VERITAS acknowledgements: VERITAS is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation and the Smithsonian Institution, by NSERC in Canada, and by the Helmholtz Association in Germany. This research used resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy's Office of Science, and resources of the National Energy Research Scientific Computing Center (NERSC), a U.S.; Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and at the collaborating institutions in the construction and operation of the instrument. We would also like to thank the referee for his/her constructive and useful comments, which were helpful to improve the manuscript. E. Molina acknowledges support from MCIN through grant BES-2016-076342. V. Bosch-Ramon acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science and Innovation under grant PID2019-105510GB-C31 and through the 'Unit of Excellence Maria de Maeztu 2020-2023 award to the Institute of Cosmos Sciences (CEX2019-000918-M). V. Bosch-Ramon is Correspondent Researcher of CONICET, Argentina, at the IAR. M. Linares has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 101002352). G. Sala acknowledges support from the Spanish MINECO grant PID2020-117252GB-I00. We acknowledge the Fermi-LAT collaboration for making available the data and the analysis tools used in this work. This research has made use of MAXI data provided by RIKEN, JAXA, and the MAXI team. This work also made use of data supplied by the UK Swift Science Data Centre at the University of Leicester. We also used data from the The Joan Oro Telescope (TJO) of the Montsec Astronomical Observatory (OAdM), which is owned by the Catalan Government and operated by the Institute for Space Studies of Catalonia (IEEC). We would also like to thank Sera Markoff, Phil Uttley, and our colleagues from the X-ray, optical/infrared, and radio communities, for the very fruitful exchanges we had on MAXI J1820+070 during the observational campaign.MAXIJ1820+070 is a low-mass X-ray binary with a black hole (BH) as a compact object. This binary underwent an exceptionally bright X-ray outburst from 2018 March to October, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 h of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy (HE) gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to similar to 500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential HE and very-HE gamma-ray emitting region should be located at a distance from the BH ranging between 10(11) and 10(13) cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA.Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEGerman BMBFGerman MPGGerman HGFItalian INFNItalian INAFSwiss National Fund SNFMCIN/AEIIndian Department of Atomic EnergyJapanese ICRRUniversity of TokyoJSPSMEXTBulgarian Ministry of Education and ScienceNational RI Roadmap ProjectAcademy of FinlandCentros de Excelencia 'Severo Ochoa' y Unidades 'María de Maeztu' program of the MCIN/AEICERCA institution of the Generalitat de CatalunyaCroatian Science Foundation (HrZZ)University of RijekaDFGPolish Ministry Of Education and ScienceMCTICCNPqFAPERJGerman Ministry for Education and Research (BMBF)Max Planck SocietyGerman Research Foundation (DFG)Helmholtz AssociationAlexander von Humboldt FoundationFrench Ministry of Higher Education, Research and InnovationCentre National de la Recherche Scientifique (CNRS/IN2P3 and CNRS/INSU)Commissariat a l'energie atomique et aux energies alternatives (CEA)U.K. Science and Technology Facilities Council (STFC)Irish Research Council (IRC)Science Foundation Ireland (SFI)Knut and Alice Wallenberg FoundationSouth African Department of Science and TechnologyNational Research FoundationUniversity of NamibiaNational Commission on Research, Science & Technology of Namibia (NCRST)Austrian Federal Ministry of Education, Science and ResearchAustrian Science Fund (FWF)Australian Research Council (ARC)Japan Society for the Promotion of ScienceUniversity of AmsterdamScience Committee of ArmeniaEGI FederationU.S. Department of Energy Office of ScienceU.S. National Science FoundationSmithsonian InstitutionNSERC in CanadaNational Energy Research Scientific Computing Center (NERSC)U.S. Department of Energy Office of Science User FacilityMCINAgencia Estatal de InvestigaciónUnidad de Excelencia María de Maeztu 2020-2023European Research Council (ERC) under the European UnionMinisterio de Asuntos Económicos y Transformación Digitalpu

Influencias del deporte en la densidad mineral ósea en niños y niñas de 8 a 12 años de edad

Tesis (Profesor de Educación Física, Licenciado en Educación)En el área de educación física, resulta muy interesante poder medir y evaluar algunos de los componentes más importantes de los huesos, órgano que juega un rol fundamental para lograr el movimiento del cuerpo. En esta investigación se realizó un estudio descriptivo transversal con el objetivo de medir la densidad mineral ósea (DMO) en niños(as) de 8 a 12 años de edad en las regiones Metropolitana y de Valparaíso. Esto generado a raíz de la problemática existente por el bajo interés que existe en realizar deporte y actividad física desde edades tempranas. Para que la población tenga un incentivo con respecto a esta situación, es necesario mostrar pruebas científicas y datos concretos, con el fin de conocer la influencia del deporte a edades tempranas en la DMO de los sujetos, evaluar los resultados obtenidos y comprobar la hipótesis que dice que “la práctica de deportes colectivos e individuales realizados en superficies sólidas, tienen mayor influencia sobre la densidad mineral ósea en niños(as) de 8 a 12 años de edad en comparación a aquellos sujetos no deportistas del mismo rango etario” Para comprobar la hipótesis se realizaron mediciones en diferentes instituciones, tales como colegios, clubes y talleres deportivos, con previa autorización vía mail o cartas para poder asistir a sus clases. Se realizó una Encuesta, además de incluir Peso, Talla, medición antropométrica y datos que eran necesarios para poder realizar la medición de DMO en hueso calcáneo. En la información recaudada se encontraron estudios anteriores que lograban concluir que los deportes que presentan impacto en los huesos como lo es el fútbol, basquetbol, voleibol, etc.; ayudan al aumento de absorción de nutrientes en los huesos, por ende, teniendo una mayor calidad de este. Luego de las mediciones y la recaudación de información los resultados del presente estudio se analizaron en base a figuras y tablas, los cuales fueron capaces de responder la pregunta de investigación y evidenciar las diferencias de los sujetos a evaluados. La hipótesis fue validada, demostrando que “la práctica de deportes colectivos e individuales realizados en superficies sólidas, tienen mayor influencia sobre la densidad mineral ósea en niños(as) de 8 a 12 años de edad en comparación a aquellos sujetos no deportistas del mismo rango etari

Case study in failure analysis of accelerated life tests (ALT) on III-V commercial triple-junction concentrator solar cells

In this work the failure analysis carried out in III-V concentrator multijunction solar cells after a temperature accelerated life test is presented. All the failures appeared have been catastrophic since all the solar cells turned into low shunt resistances. A case study in failure analysis based on characterization by optical microscope, SEM, EDX, EQE and XPS is presented in this paper, revealing metal deterioration in the bus bar and fingers as well as cracks in the semiconductor structure beneath or next to the bus bar. In fact, in regions far from the bus bar the semiconductor structure seems not to be damaged. SEM images have dismissed the presence of metal spikes inside the solar cell structure. Therefore, we think that for these particular solar cells, failures appear mainly as a consequence of a deficient electrolytic growth of the front metallization which also results in failures in the semiconductor structure close to the bus bars

Detection of the Geminga pulsar with MAGIC hints at a power-law tail emission beyond 15 GeV

We report the detection of pulsed gamma-ray emission from the Geminga pulsar (PSR J0633+1746) between 15 GeV and 75 GeV. This is the first time a middle-aged pulsar has been detected up to these energies. Observations were carried out with the MAGIC telescopes between 2017 and 2019 using the low-energy threshold Sum-Trigger-II system. After quality selection cuts, similar to 80 h of observational data were used for this analysis. To compare with the emission at lower energies below the sensitivity range of MAGIC, 11 years of Fermi-LAT data above 100 MeV were also analysed. From the two pulses per rotation seen by Fermi-LAT, only the second one, P2, is detected in the MAGIC energy range, with a significance of 6.3 sigma. The spectrum measured by MAGIC is well-represented by a simple power law of spectral index Gamma =5.62 +/- 0.54, which smoothly extends the Fermi-LAT spectrum. A joint fit to MAGIC and Fermi-LAT data rules out the existence of a sub-exponential cut-off in the combined energy range at the 3.6 sigma significance level. The power-law tail emission detected by MAGIC is interpreted as the transition from curvature radiation to Inverse Compton Scattering of particles accelerated in the northern outer gap

Search for Very High-energy Emission from the Millisecond Pulsar PSR J0218+4232

PSR J0218+4232 is one of the most energetic millisecond pulsars known and has long been considered as one of the best candidates for very high-energy (VHE; >100 GeV) gamma-ray emission. Using 11.5 yr of Fermi Large Area Telescope (LAT) data between 100 MeV and 870 GeV, and similar to 90 hr of Major Atmospheric Gamma Imaging Cherenkov (MAGIC) observations in the 20 GeV to 20 TeV range, we searched for the highest energy gamma-ray emission from PSR J0218+4232. Based on the analysis of the LAT data, we find evidence for pulsed emission above 25 GeV, but see no evidence for emission above 100 GeV (VHE) with MAGIC. We present the results of searches for gamma-ray emission, along with theoretical modeling, to interpret the lack of VHE emission. We conclude that, based on the experimental observations and theoretical modeling, it will remain extremely challenging to detect VHE emission from PSR J0218+4232 with the current generation of Imaging Atmospheric Cherenkov Telescopes, and maybe even with future ones, such as the Cherenkov Telescope Array

MAGIC Observations of the Nearby Short Gamma-Ray Burst GRB 160821B

The coincident detection of GW170817 in gravitational waves and electromagnetic radiation spanning the radio to MeV gamma-ray bands provided the first direct evidence that short gamma-ray bursts (GRBs) can originate from binary neutron star (BNS) mergers. On the other hand, the properties of short GRBs in high-energy gamma-rays are still poorly constrained, with only similar to 20 events detected in the GeV band, and none in the TeV band. GRB 160821B is one of the nearest short GRBs known at z = 0.162. Recent analyses of the multiwavelength observational data of its afterglow emission revealed an optical-infrared kilonova component, characteristic of heavy-element nucleosynthesis in a BNS merger. Aiming to better clarify the nature of short GRBs, this burst was automatically followed up with the MAGIC telescopes, starting from 24 s after the burst trigger. Evidence of a gamma-ray signal is found above similar to 0.5 TeV at a significance of similar to 3 sigma during observations that lasted until 4 hr after the burst. Assuming that the observed excess events correspond to gamma-ray emission from GRB 160821B, in conjunction with data at other wavelengths, we investigate its origin in the framework of GRB afterglow models. The simplest interpretation with one-zone models of synchrotron-self-Compton emission from the external forward shock has difficulty accounting for the putative TeV flux. Alternative scenarios are discussed where the TeV emission can be relatively enhanced. The role of future GeV-TeV observations of short GRBs in advancing our understanding of BNS mergers and related topics is briefly addressed

Proton acceleration in thermonuclear nova explosions revealed by gamma rays

Classical novae are cataclysmic binary star systems in which the matter of a companion star is accreted on a white dwarf(1,2). Accumulation of hydrogen in a layer eventually causes a thermonuclear explosion on the surface of the white dwarf(3), brightening the white dwarf to similar to 10(5) solar luminosities and triggering ejection of the accumulated matter. Novae provide the extreme conditions required to accelerate particles, electrons or protons, to high energies. Here we present the detection of gamma rays by the MAGIC telescopes from the 2021 outburst of RS Ophiuchi, a recurrent nova with a red giant companion, which allowed us to accurately characterize the emission from a nova in the 60 GeV to 250 GeV energy range. The theoretical interpretation of the combined Fermi LAT and MAGIC data suggests that protons are accelerated to hundreds of gigaelectronvolts in the nova shock. Such protons should create bubbles of enhanced cosmic ray density, of the order of 10 pc, from the recurrent novae

Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre

We provide an updated assessment of the power of the Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at the TeV scale, via the associated gamma-ray signal from pair-annihilating dark matter particles in the region around the Galactic centre. We find that CTA will open a new window of discovery potential, significantly extending the range of robustly testable models given a standard cuspy profile of the dark matter density distribution. Importantly, even for a cored profile, the projected sensitivity of CTA will be sufficient to probe various well-motivated models of thermally produced dark matter at the TeV scale. This is due to CTA's unprecedented sensitivity, angular and energy resolutions, and the planned observational strategy. The survey of the inner Galaxy will cover a much larger region than corresponding previous observational campaigns with imaging atmospheric Cherenkov telescopes. CTA will map with unprecedented precision the large-scale diffuse emission in high-energy gamma rays, constituting a background for dark matter searches for which we adopt state-of-the-art models based on current data. Throughout our analysis, we use up-to-date event reconstruction Monte Carlo tools developed by the CTA consortium, and pay special attention to quantifying the level of instrumental systematic uncertainties, as well as background template systematic errors, required to probe thermally produced dark matter at these energies