New method for analytical photovoltaic parameters identification: meeting manufacturer’s datasheet for different ambient conditions

At present, photovoltaic energy is one of the most important renewable energy sources. The demand for solar panels has been continuously growing, both in the industrial electric sector and in the private sector. In both cases the analysis of the solar panel efficiency is extremely important in order to maximize the energy production. In order to have a more efficient photovoltaic system, the most accurate understanding of this system is required. However, in most of the cases the only information available in this matter is reduced, the experimental testing of the photovoltaic device being out of consideration, normally for budget reasons. Several methods, normally based on an equivalent circuit model, have been developed to extract the I-V curve of a photovoltaic device from the small amount of data provided by the manufacturer. The aim of this paper is to present a fast, easy, and accurate analytical method, developed to calculate the equivalent circuit parameters of a solar panel from the only data that manufacturers usually provide. The calculated circuit accurately reproduces the solar panel behavior, that is, the I-V curve. This fact being extremely important for practical reasons such as selecting the best solar panel in the market for a particular purpose, or maximize the energy extraction with MPPT (Maximum Peak Power Tracking) methods

Development of a calibration satellite for a CMB telescope flying in formation about L2 libration point

Trabajo presentado a la 8th European Conference for aeronautics and aerospace sciences (EUCASS), celebrada en Madrid (España) del 1 al 4 de julio de 2019.The new generation of cosmic microwave background (CMB) telescopes have reached unprecedented levels of sensitivity. These telescopes measure several cosmological parameters with different levels of accuracy. In particular, considerable effort has been made to measure the B-mode polarization, which is related to the inflationary process of the universe. The power spectrum of this signal is about four orders of magnitude fainter than the CMB temperature power spectrum. Due to the signal weakness, the instruments must be subjected to calibration processes before and after launching. Additionally, data from the same sky area is gathered repeatedly to mitigate during data analysis the systematic errors induced by instruments. Celestial sources are often used as an external reference for calibration after launch, but these sources are not perfectly characterized. In this paper we study the concept of using a calibration satellite (CalSat) flying in formation with a CMB telescope in an orbit located at the second Lagrange point (L2). The CalSat is conceived as a micro satellite (10-100 kg) and serves as a perfectly known source of a reference signal to reduce the polarization angle measurement uncertainty. According to the scanning law followed by the telescope, the influence of the relative position between the spacecrafts in the calibration process is studied. The relative motion of the spacecrafts is considered with a simplified dynamic model. Based on the mission requirements, the different subsystems are sized and a preliminary design to evaluate the feasibility is obtained. The design has been carried out under the principle of reducing at minimum the impact on the telescope architecture. It would require to be launched along with the telescope to reach L2 at the same time and being able to communicate with the telescope. This new calibration element could have a huge impact on the performance of this kind of missions, providing a significant improvement in the measurements accuracy without requiring new and costly technological developments.The authors would like to thank Spanish Ministry for Economy and Competitiveness (currently Ministry of Science,innovation and Universities) for the financial support provided under the projects with references ESP2017-92135-EXP all co-financed with EU FEDER funds

A descriptive and quantitative approach regarding erosion and development of landforms on abandoned mine tailings: New insights and environmental implications from SE Spain

The San Cristóbal–Perules mining site in Mazarrón in southeast Spain was subjected to about a hundred years of intense mining activity for lead, silver, and zinc. Metallurgical operations (smelting, calcination, gravity concentration) carried out during the late nineteenth century–early twentieth century induced significant land transformation, and the most conspicuous wastes of this period consist of a chaotic piling of ‘old’ tailing deposits. Later on, during the mid-twentieth century, ‘modern’ tailings resulting from froth flotation were accumulated filling small valleys; these latter valley-fill tailings rose sequentially according to the upstream construction method, progressively raising the level of the dam during the process. Once abandoned, both types of tailing deposits underwent severe erosion, resulting in a mosaic of erosional and sedimentary landforms developed upon (e.g., gully formation) and within them (e.g., piping). We made an inventory and classification of these landforms. Our study shows the geomorphic work to reestablish a new steady state between the tailings deposits and the local erosive conditions. This scenario implies several hazards related to the extremely high heavy metal contents of these tailings and the geomorphic instability of the deposits. We also quantified the tailings tonnage and erosion that occurred at one of the tailings dams (El Roble). As shown by an oblique aerial photograph taken in 1968, this dam had a terraced topography, whereas in 2013 this morphology had evolved into a badland-type relief with deep parallel gullies. By recognizing and surveying specific, remnant points along the benches and outslopes of the older terraced topography, we were able to build up a first digital elevation model (DEM1) reflecting the initial topography. A second DEM, this time showing the present topography, allowed quantification of erosion via Material Loss = DEM1 − DEM2. This yields an erosion rate (1968–2009) of 151.8 Mg (MT) ha− 1 y− 1, which matches well typical values for erosion of mined areas, commonly above 100 Mg (MT) ha− 1 y− 1. Abandoned mine tailing deposits are extremely common in the semiarid scenarios of the SW USA, Australia, Chile, and Peru. Given the similarities of these scenarios with SE Spain, the example from Mazarrón may provide useful new insights regarding the erosion and geomorphic evolution of such tailing deposits. These matters should be addressed in key environmental actions such as mine closure plans and land reclamation projects. A solution may come via restoration of these deposits through landform design involving the building up of stable mature landscapes, which in turn can withstand erosion much more easily.Peer reviewe

Using the new technologies in claudication patients: CReTe: Claudication patients and telematic register

Objetivo: Presentamos una aplicación informática para teléfonos móviles ideada para el control de sesiones de ejercicio domiciliario en claudicantes. Exponemos también nuestros resultados preliminares. Material y métodos: La aplicación está dise˜nada para teléfonos móviles con sistema operativo Android, tecnología de geolocalización y conexión de datos. Está conectada a una base de datos codificada que preserva el secreto médico. Los datos que se recogen de las sesiones de ejercicio son la fecha, la hora de inicio y de fin, el tiempo dedicado, el número de las paradas realizadas y la velocidad máxima, la velocidad media global y la velocidad entre paradas. Durante el mes de enero de 2014 se reclutó a aquellos pacientes que aceptaran el estudio, poseyeran y entendieran un dispositivo móvil Android con geolocalización y conexión de datos. Los criterios de exclusión del estudio una vez comenzado fueron progresión hacia isquemia arterial crítica, enfermedad intercurrente grave, fallecimiento y ausencia de comunicación con el paciente. Se recogieron las principales morbilidades y los resultados de los cuestionarios de calidad de vida SF36 y EuroQol 5D. Se midió el tiempo de primera consulta y el tiempo dedicado por semana y paciente durante un seguimiento de 28 días. Se calculó el cumplimiento de las sesiones con respecto a las sesiones pactadas con cada paciente, con un mínimo de 2 semanales. Resultados: Un total de 5 pacientes fueron incluidos, con edad media de 59,3 a˜nos (mediana 52; rango 40-80). De ellos 2 se excluyeron, uno por progresión a isquemia crítica y otro por ausencia de comunicación. El tiempo medio dedicado por consulta nueva fue de 29,1 min (mediana 27,5; rango 45-20). El cumplimiento de las sesiones fue del 100% en 2 pacientes y del 63% en otro. El tiempo dedicado en el seguimiento semanal por paciente fue de 1,68 min. Conclusiones: CReTe es una herramienta aplicable a nuestro medio que precisa de estudios mayores para demostrar su utilidad.Objective: The preliminary results are presented on the use of a new application for mobile phones designed to control home exercise sessions in claudication.Materials and methods: The application is designed for Android systems with geolocation tech-nology and Internet connection. It is connected to a database encoded to ensure medical confidentiality. The data collected from the exercise sessions were the date, start time and end time, the time spent, the number of stops made, and the maximum speed, average speed and overall speed between stops. During the month of January 2014 patients who accepted and understood the study, and possessed an Android mobile device with geolocation and data connection, were enrolled. The exclusion criteria, 11 the study started, were progression to arterial ischemia, severe intercurrent illness, non-communication with the patient, and death. Major morbidities and results of quality of life questionnaires SF36 and EuroQol 5 D were collec-ted. Time of first consultation and time spent per week per patient during a 28-day follow-up was recorded. Compliance as regards the agreed sessions was calculated for each patient, with a minimum of 2 weeks.Results: The study included 5 patients with a mean age 59.3 years (median 52; range 40-80). Of these, 2 were excluded, one for progression to critical ischemia and another for non-communication. The average time spent in a new consultation was 29.1 minutes (median 27.5, range 45-20). The compliance with the sessions was 100% in 2 patients, and 63% in another. Time spent in the weekly monitoring per patient was 1.68 minutes.Conclusions: CReTe is an applicable tool in our environment that requires further study to demonstrate its usefulness

The Mazarrón basin, SE Spain: a study of mineralization processes, evolving magmatic series, and geothermal activity

The Miocene to Present Mazarrón basin provides a window on the metallogenic role of an evolving magmatic series. High-K calc–alkaline magmas gave rise to an important cluster of Pb–Zn–Ag–Cu vein and stockwork deposits emplaced in dacitic to rhyodacitic domes, part of a complex volcanic–metallogenic province (Au, Hg, Pb–Zn–Cu–Ag, Sn) stretching for ∼150 km along the Mediterranean coast of SE Spain. By Pliocene time the former magmatic series had been replaced by intraplate alkaline basaltic volcanism, thus becoming the southern branch of the Western/Central Europe alkaline province. In terms of base metal sulphide deposits, this European province is barren, although it triggered widespread, CO2-rich geothermal activity. Modern geothermal activity at El Saladillo (Mazarrón) resulted in the deposition of carbonate sinter deposits and formation of microbial mats. Proximal facies consist of millimetric to centimetric multicoloured layers of microbial mats, including yellow-orange thin bands of calcified bacteria and mineral growths of aragonite and calcite; green layers of live thermophilic Lyngbya-type cyanobacteria; black, degraded organic matter; and pyrite as the sole sulphide phase. Except for arsenic (37–63 μg g−1), all of the studied trace elements (Ag, Ba, Bi, Cd, Cu, Pb, Sb, Se, and Sn) appear in remarkably low concentrations in the geothermal sinters. This is consistent with compositional data for the El Saladillo waters, with no significant metal concentrations. We present the first conceptual model (Miocene to Present) for the ore-forming processes, magmatism, CO2 degasification, and geothermal activity for this realm. We argue that the time- and space-limited character of this volcanism (small, scattered outcrops), the deep magma emplacement level, the metal sulphide behaviour in alkaline basaltic magmatic chambers, and the dry character of these magmas prevented any metallogenic interaction between the chambers and the much shallower meteoric waters that drove the El Saladillo geothermal system and others of the same kind in Spain and elsewhere in Europe

Low friction along the high slip patch of the 2011 Mw 9.0 Tohoku-Oki earthquake required from the wedge structure and extensional splay faults

We analyze the mechanical properties needed to account for the large shallow slip during the 2011 Tohoku-Oki earthquake and the activation of landward normal faulting within the forearc. We show that the morphology and internal structure of the forearc follows closely the prediction of the critical Coulomb wedge in horizontal compression, implying a high internal pore pressure ratio (λ = 0.7 + 0.14/ – 0.48) and a low effective basal friction (μ^(eff)_b = 0.14 + 0.18/ – 0.04). We then show that the activation of the normal fault requires a lower effective basal friction beneath the outer wedge than beneath the inner wedge (μ_outer ≤ 0.015), possibly due to transient dynamic weakening associated to the seismic rupture. Forearc normal faults could be considered as evidence for very efficient dynamic weakening along the megathrust and typify megathrust with high tsunamigenic potential

COVID-19 and dengue coinfection in Latin America: A systematic review

"Introduction: Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has spread globally, becoming a long-lasting pandemic. Dengue is the most common arboviral disease in tropical and subtropical regions worldwide. COVID-19 and dengue coinfections have been reported, associated with worse outcomes with significant morbidity and mortality. Therefore, this study aims to determine the epidemiological situation of COVID-19 and dengue coinfection in Latin America. Methods: A systematic literature review was performed using PubMed, Scopus, Embase, Web of Science, LILACS, and BVS databases from January 1, 2020, to September 4, 2021. The key search terms used were ""dengue"" and ""COVID-19"". Results: Nineteen published articles were included. The studies were case reports with a detailed description of the coinfection’s clinical, laboratory, diagnostic, and treatment features. Conclusion: Coinfection with SARS-CoV-2 and dengue virus is associated with worse outcomes with significant morbidity and mortality. The similar clinical and laboratory features of each infection are a challenge in accurately diagnosing and treating cases. Establishing an early diagnosis could be the answer to reducing the estimated significant burden of these conditions.