Estudio de la demanda de energía eléctrica en edificios universitarios para su abastecimiento parcial con generación fotovoltaica

Los edificios educativos del Nordeste Argentino presentan características adecuadas al momento de considerar la implementación de un suministro parcial de electricidad por generación fotovoltaica. Se exponen los primeros resultados del análisis y caracterización de la demanda de energía eléctrica en edificios universitarios de la región para determinar el impacto sobre la misma de un sistema de generación fotovoltaica. Se comenzó realizando un estudio del consumo eléctrico a fin de describir sus características y detectar ineficiencias que puedan subsanarse antes de implementar la generación renovable. Este estudio se extiende a cinco Facultades localizadas en la ciudad de Resistencia. Cuatro de ellas pertenecientes a la Universidad Nacional del Nordeste y la restante perteneciente a la Universidad Tecnológica Nacional. Con esta información se procede a diseñar y dimensionar un sistema de generación fotovoltaica determinándose la porción de la demanda que se podrá satisfacer.Educational buildings in the Northeast of Argentina present adequate characteristics at the moment of considering the implementation of partial electricity supply by photovoltaic generation. First results of the analysis and characterization of the demand of electric energy in university buildings of the region are presented, to determine the impact of a photovoltaic generation system on it. It began by conducting a study of electricity consumption in order to describe its characteristics and to detect inefficiencies that can be remedied before implementing renewable generation. This study extends to five Faculties located in the city of Resistencia. Four of them belonging to the Universidad Nacional del Nordeste and the last one belonging to the Universidad Tecnológica Nacional. With this information it proceeds to design and size a photovoltaic generation system, determining the portion of the demand that can be satisfied.Fil: Zurlo, Hugo D.. Universidad Tecnológica Nacional (Argentina). Facultad Regional ResistenciaFil: Vargas, Orlando C.. Universidad Tecnológica Nacional (Argentina). Facultad Regional Resistenci

Effects of individual differences and job characteristics on the psychological health of Italian nurses

The Demand Resources and Individual Effects Model (DRIVE Model) is a transactional model that integrates Demands- Control-Support and Effort-Reward Imbalance models emphasising the role of individual (Coping Strategies; Overcommitment) and job characteristics (Job Demands, Social Support, Decision Latitude, Skill Discretion, Effort, Rewards) in the work-related stress process. The present study aimed to test the DRIVE Model in a sample of 450 Italian nurses and to compare findings with those of a study conducted in a sample of UK nurses. A questionnaire composed of Ways of Coping Checklist-Revised (WCCL-R); Job Content Questionnaire (JCQ); ERI Test; Hospital Anxiety and Depression Scale (HADS) was used. Data supported the application of the DRIVE Model to the Italian context, showing significant associations of the individual characteristics of Problem-focused, Seek Advice and Wishful Thinking coping strategies and the job characteristics of Job Demands, Skill Discretion, Decision Latitude, and Effort with perceived levels of Anxiety and Depression. Effort represented the best predictor for psychological health conditions among Italian nurses, and Social Support significantly moderated the effects of Job Demands on perceived levels of Anxiety. The comparison study showed significant differences in the risk profiles of Italian and UK nurses. Findings were discussed in order to define focused interventions to promote nurses’ wellbeing

Detection of Sharp Symmetric Features in the Circumbinary Disk Around AK Sco

The Search for Planets Orbiting Two Stars (SPOTS) survey aims to study the formation and distribution of planets in binary systems by detecting and characterizing circumbinary planets and their formation environments through direct imaging. With the SPHERE Extreme Adaptive Optics instrument, a good contrast can be achieved even at small (<300 mas) separations from bright stars, which enables studies of planets and disks in a separation range that was previously inaccessible. Here, we report the discovery of resolved scattered light emission from the circumbinary disk around the well-studied young double star AK Sco, at projected separations in the ~13--40 AU range. The sharp morphology of the imaged feature is surprising, given the smooth appearance of the disk in its spectral energy distribution. We show that the observed morphology can be represented either as a highly eccentric ring around AK Sco, or as two separate spiral arms in the disk, wound in opposite directions. The relative merits of these interpretations are discussed, as well as whether these features may have been caused by one or several circumbinary planets interacting with the disk.Comment: 10 pages, 3 figures, accepted for publication in ApJ Letters. Minor (proof-level) corrections implemented in this versio

The gravitational mass of Proxima Centauri measured with SPHERE from a microlensing event

Proxima Centauri, our closest stellar neighbour, is a low-mass M5 dwarf orbiting in a triple system. An Earth-mass planet with an 11 day period has been discovered around this star. The star's mass has been estimated only indirectly using a mass-luminosity relation, meaning that large uncertainties affect our knowledge of its properties. To refine the mass estimate, an independent method has been proposed: gravitational microlensing. By taking advantage of the close passage of Proxima Cen in front of two background stars, it is possible to measure the astrometric shift caused by the microlensing effect due to these close encounters and estimate the gravitational mass of the lens (Proxima Cen). Microlensing events occurred in 2014 and 2016 with impact parameters, the closest approach of Proxima Cen to the background star, of 1\farcs6 $\pm$ 0\farcs1 and 0\farcs5 $\pm$ 0\farcs1, respectively. Accurate measurements of the positions of the background stars during the last two years have been obtained with HST/WFC3, and with VLT/SPHERE from the ground. The SPHERE campaign started on March 2015, and continued for more than two years, covering 9 epochs. The parameters of Proxima Centauri's motion on the sky, along with the pixel scale, true North, and centering of the instrument detector were readjusted for each epoch using the background stars visible in the IRDIS field of view. The experiment has been successful and the astrometric shift caused by the microlensing effect has been measured for the second event in 2016. We used this measurement to derive a mass of 0.150$^{\textrm{+}0.062}_{-0.051}$ (an error of $\sim$ 40\%) \MSun for Proxima Centauri acting as a lens. This is the first and the only currently possible measurement of the gravitational mass of Proxima Centauri.Comment: 10 pages, 6 figures, accepted by MNRA

Evidence For The Production Of Slow Antiprotonic Hydrogen In Vacuum

We present evidence showing how antiprotonic hydrogen, the quasistable antiproton-proton (pbar-p) bound system, has been synthesized following the interaction of antiprotons with the hydrogen molecular ion (H2+) in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events, evidence is presented for antiprotonic hydrogen production with sub-eV kinetic energies in states around n=70, and with low angular momenta. The slow antiprotonic hydrogen may be studied using laser spectroscopic techniques.Comment: 5 pages with 4 figures. Published as Phys. Rev. Letters 97, 153401 (2006), in slightly different for

Cold-Antimatter Physics

The CPT theorem and the Weak Equivalence Principle are foundational principles on which the standard description of the fundamental interactions is based. The validity of such basic principles should be tested using the largest possible sample of physical systems. Cold neutral antimatter (low-energy antihydrogen atoms) could be a tool for testing the CPT symmetry with high precision and for a direct measurement of the gravitational acceleration of antimatter. After several years of experimental efforts, the production of low-energy antihydrogen through the recombination of antiprotons and positrons is a well-established experimental reality. An overview of the ATHENA experiment at CERN will be given and the main experimental results on antihydrogen formation will be reviewed.Comment: Proceedings of the XLIII International Meeting on Nuclear Physics, Bormio (Italy), March 13-20 (2005). 10 pages, 4 figures, 1 tabl

Detection of antihydrogen annihilations with a Si-micro-strip and pure CsI detector

In 2002, the ATHENA collaboration reported the creation and detection of cold (~15 K) antihydrogen atoms [1]. The observation was based on the complete reconstruction of antihydrogen annihilations, simultaneous and spatially correlated annihilations of an antiproton and a positron. Annihilation byproducts are measured with a cylindrically symmetric detector system consisting of two layers of double sided Si-micro-strip modules that are surrounded by 16 rows of 12 pure CsI crystals (13 x 17.5 x 17 mm^3). This paper gives a brief overview of the experiment, the detector system, and event reconstruction. Reference 1. M. Amoretti et al., Nature 419, 456 (2002).Comment: 7 pages, 5 figures; Proceedings for the 8th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications (Como, Italy October 2003) to be published by World Scientific (style file included

ATHENA -- First Production of Cold Antihydrogen and Beyond

Atomic systems of antiparticles are the laboratories of choice for tests of CPT symmetry with antimatter. The ATHENA experiment was the first to report the production of copious amounts of cold antihydrogen in 2002. This article reviews some of the insights that have since been gained concerning the antihydrogen production process as well as the external and internal properties of the produced anti-atoms. Furthermore, the implications of those results on future prospects of symmetry tests with antimatter are discussed.Comment: Proc. of the Third Meeting on CPT and Lorentz Symmetry, Bloomington (Indiana), USA, August 2004, edited by V. A. Kostelecky (World Scientific, Singapore). 10 pages, 5 figures, 1 table. Author affiliations cor