Thermal-hydraulic and optical modeling of solar Direct Steam Generation systems based on Parabolic-Trough Collectors

Not only the round absorber tube has been studied, but as a matter of example, the potential of the IMCRT method has also been applied to flat absorbers. A thermal model of a linear receiver has also been performed to describe the heat transfer mechanisms between all the elements on it. Heat diffusion in the absorber tube wall as well as the glass cover has been modeled in 3D, whereas the fluid domain (superheated steam) has been simplified according to a 1D approach. Results have been validated with experimental data from the DISS facility located at Plataforma Solar de Almería. Besides, a detailed thermal-hydraulic study has also been carried out by means of the commercial code RELAP5. This code is based on a transient two-fluid model where both, single-phase and two-phase flow regions can be simulated. Thermal behavior of the absorber tube can also be approximated by means of the standard capabilities of RELAP5. A full and detailed model of the DISS facility has been performed where the connection pipes between adjacent collectors have been included. This model has been validated with experimental data obtained from full day tests getting a good agreement. According to the results, the 1D approach followed by RELAP5 is able to reproduce transient phenomena which usually take place in common operation conditions. In addition, heat losses have been experimentally characterized in the same facility. A new correlation, which takes into account heat losses of receivers after two years and a half of operation, is proposed and included in the model. Thermal-hydraulic codes also make it possible to study severe slugging in connection pipes. For that purpose, a particular connection pipe alongside their two adjacent collectors have been simulated to figure out in which range of operation conditions severe slugging occurs at a pressure of 0.5 MPa.CSP systems based on Parabolic-Trough Collectors (PTCs) account for a representative share of the global solar thermal capacity installed. Most of the existing PTC power plants use synthetic oil as heat transfer fluid. However, water can be alternatively used, where both single and two-phase flow occur. This technology is called Direct Steam Generation (DSG) and it presents some advantages in terms of system overall efficiency and plant cost reduction. Nevertheless, some complexities inherent to two-phase flow have to be addressed to succeed in the commercial deployment of DSG. The development of numerical codes to model such systems is of key importance to put new insights into them. Both, the thermal-hydraulic and optical modeling are of relevance. Conventional parabolic-trough reflectors concentrate solar radiation on absorber tubes following a characteristic pattern with a non-homogeneous distribution in the angular direction. It means that the bottom half of the absorber tube receives much more flux than the upper half. Under specific two-phase flow patterns (e.g. stratified flow) the refrigeration of the absorber tube is not homogeneous and thermal bending may take place. This problem can also be reported in single-phase flow conditions (e.g. superheated steam), where a significant thermal gradient at the cross-sectional plane of the absorber tube can be critical. A new technique called Inverse Monte Carlo Ray Tracing (IMCRT) method is proposed in this thesis. It aims to design new reflector geometries so that a more homogeneous distribution of concentrated solar radiation on the absorber tube can be accomplished. In line with this, new reflector geometries have been proposed with the same aperture width as the LS-3 design for the same absorber design, where quasi-constant flux distribution is achieved within a specific angular range

Effect of irrigation on the yield of alfalfa for hay in Valle Central of Catamarca, Argentina

En la provincia de Catamarca existe una gran superficie cultivada con alfalfa bajo riego. La falta de conocimiento de los requerimientos hídricos del cultivo en esta zona es un grave inconveniente. Con el objeto de subsanar este problema, se realizó en el Valle Central un ensayo de riego con un diseño en bloques completamente al azar, con cuatro tratamientos y cuatro repeticiones. Los tratamientos consistieron en la reposición de humedad al suelo a distintos umbrales: 75, 50, 25 y 0% de la capacidad de almacenamiento total de agua del suelo. Se evaluó la producción de materia seca en cada tratamiento durante siete cortes. Los resultados mostraron que al regar con un umbral del 75 o del 50% se obtienen rendimientos promedio similares de materia seca: 25.674,4 kg.ha-1.año-1 y 24.215,4 kg.ha-1.año-1 respectivamente. El trabajo muestra que hay diferencias significativas (p < 0,0001) entre las medias de estos tratamientos con respecto a los otros dos, que tienen rendimientos inferiores: 16.366,7 kg.ha-1.año-1 para el umbral de riego del 25% y de 9.970,9 kg.ha-1.año-1 para un umbral del 0%. Se concluyó que la producción del cultivo disminuye considerablemente con intervalos de riego muy prolongados.In the province of Catamarca there is a large area planted with alfalfa. Lack of knowledge of crop water requirements in this area constitutes a serious problem. An irrigation experiment was conducted in randomized blocks in Valle Central with four treatments and four replications. The treatments consisted in replenishing soil moisture content at different thresholds: 75, 50, 25 and 0% of the total soil water storage capacity. Dry-matter production per treatment was evaluated in seven cuttings. Results showed that when irrigating with a 75 and a 50% threshold, similar dry-matter yields were obtained equivalent to 25,674.4 kg ms.ha-1 and 24,215.4 kg ms.ha-1, respectively. Significant differences were found (p < 0.0001) between the means of these treatments and the other two treatments. An irrigation threshold of 25% yielded less than16,366.7 kg.ha-1 and an irrigation threshold of 0% yielded less than 9,970.9 kg.ha-1. It can be concluded that alfalfa production is significantly reduced when irrigation intervals are very long.Fil: Demin, Pablo Enrique. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Catamarca.Fil: Aguilera, Juan José. Instituto Nacional de Tecnología Agropecuaria (Argentina). Centro Regional Mendoza-San Juan

Acidification of musts in warm regions with tartaric acid and calcium sulfate at industrial scale

Acidification of musts is necessary in warm areas where high temperatures during ripening accelerate breathing combustion of tartaric acid and, in particular, malic acid in the berries. L(+) tartaric acid, L(-) or D,L malic acid and lactic acids are the only chemical acidifiers authorized by the OIV and European Community regulations. The use of calcium sulfate (gypsum: CaSO4·2H2O) is also authorized in the European Community as a complementary acidifier in generous and generous liquor wines from Spain (a practice known as plastering), provided that the residual sulfate content in the wine does not exceed 2.5 g/L expressed as potassium sulfate. However, this practice is not yet approved by OIV. To predict the effect on pH of different acidifiers, several chemical modeling approaches have been described in the literature, in particular a simplified model where the acidity of wine is considered to be due to a monoprotic acid. The aim of this work is to verify this model at pilot and industrial scale in the acidification of musts with tartaric and calcium sulfate, added either individually and in combination, using doses up to 3 g/L and to study the modifications that these practices produce on the compositions of the resulting wines. This work supplies useful information to study this practice in OIV in order to consider its approval

Horizontal Inequity in Access to Healthcare Services and Educational Level in Spain

The aim of this study is to measure horizontal equity in the use of healthcare services in Spain, proposing two methodological innovations. First by defending it as equality of access for equal need, irrespective of educational level, unlike the prevailing methodological approach to horizontal equity which relates it to income. Second, by estimating it by means of the slope index of the inequality of characteristics, analagous to the inequity index proposed by Kakwani, Wagstaff and van Doorslaer (1997; HIWV) but presenting some methodological advantages, the greater robustness of the data available on educational level than of those on income, and the possibility of isolating the net effect of the educational level on the use of healthcare by controlling for other variables. The methodology is designed in three parts: (1) estimation of the relationship between the educational level and the use of healthcare services by means of a model of the likelihood of demand for healthcare services, commonly used in the literature; (2) estimation of the relationship between educational level and health by approximating a production function of individuals' health according to their personal characteristics and other factors conditioning health; and (3) estimation of the slope index of inequality as a measure of horizontal inequity, using educational level instead of income as the criterion for ranking individuals. The data base used was a sample of 55,598 observations from the Survey of disabilities, handicaps and state of health of 1999, carried out in Spain. No significant statistical association was found between educational level and use of healthcare services. On the other hand, the relationship between educational level and health, with the three proxy variables used (perception of health, days of limitation and number of chronic illnesses) shows a positive correlation, i.e. an increase in educational level is associated with a greater probability of enjoying better health. Horizontal inequity, measured by the proposed slope index of inequality, gives a range of statistically significant values between 13.91% and 9.40%, depending on cases, i.e. the significant inverse relationship between state of health and educational level is not reflected proportionally in healthcare use, implying that, with greater need, the access of individuals with a lower educational level to public healthcare services is the same as for the rest. These results suggest that the educational level may be a variable to consider when characterizing the healthcare needs of a population in a defined geographical area, at least from the normative characterization of horizontal equity proposedEducation and health; Healthcare needs; Horizontal Inequity; Logistic regression ; Ordinal regression; Regional funding

Nuevos retos y empleabilidad del profesional de la Pedagogía. Estudio mixto de trayectorias profesionales

La Pedagogía y la figura del profesional en dicha disciplina han evolucionado vertiginosamente en los últimos años. Los planes de estudio universitarios han ido dibujando un perfil profesional cada vez más orientado a considerar la Pedagogía como una disciplina transversal y adaptable a contextos muy variados de intervención, mucho más allá del ámbito escolar: empresas, orientación laboral, TIC, recursos humanos, etc… En esta investigación se ha analizado cómo han evolucionado las trayectorias profesionales de pedagogos y pedagogas; cómo el bagaje de estos profesionales, se ha ido enriqueciendo desarrollando tareas, asumiendo nuevos retos y responsabilidades, que han otorgando unos rasgos distintivos y nuevas competencias a esta profesión. La idea fuerza de esta investigación es que el análisis y la interpretación de trayectorias individuales de profesionales, puede permitir la profundización en el conocimiento de los sectores en los que la Pedagogía está emergiendo, así como su potencial de empleabilidad. Por tanto, se trató de analizar la empleabilidad del pedagogo/a a través de la interpretación de trayectorias profesionales individuales, los puestos de trabajo desempeñados, las funciones y tareas realizadas, así como las percepciones sobre su propia trayectoria profesional. La investigación se ha realizado empleando una metodología mixta basada en encuestas y entrevistas en profundidad. El cuestionario construido, aplicado a profesionales de la Pedagogía en ejercicio (n1 = 142), permitió obtener una perspectiva general de la profesión, lo que ofreció una visión actual del contexto laboral y de los sectores donde el pedagogo/a ejerce su actividad, además de ayudar a seleccionar los perfiles profesionales que más se ajustaban a los objetivos de la investigación. La entrevista en profundidad se aplicó a una selección de informantes (n2 = 4) que habían destacado por su desarrollada carrera laboral en la Pedagogía. A partir de los resultados de la parte cuantitativa, se observó cómo los profesionales encuestados se distribuyen mayoritariamente en empresas de titularidad públicas, aunque cada vez más cerca de las posibilidades de empleabilidad del profesional de la pedagogía en el sector privado (48,9%). En lo relativo a los planes de estudio, se puede afirmar que existe una clara tendencia a la homogeneización de las enseñanzas con la implantación del Espacio Europeo. En lo que concierne a las competencias (se valoraron 31), se observó que, existe un desarrollo importante en aquellas relacionadas con los aspectos legales y más teóricos de la disciplina y que destacan en el diseño de programas socioeducativos. En lo que respecta a los resultados más destacados de la fase cualitativa, se observa cómo se encuentran elementos comunes en las diferentes trayectorias profesionales, en cuanto a carencias y sobretodo necesidades, retos y oportunidades en el quehacer diario del profesional de la pedagogía. Se identificaron 14 categorías ad hoc de las cuales, tras un primer análisis de coocurrencias, se establecieron cuatro de ellas como categorías principales: Vocación, Competencias, Ámbitos de intervención y Nichos de trabajo alternativo. Cada una de ellas permitió construir diversos diagramas comprensivos que permiten analizar en profundidad qué factores se relacionan con las trayectorias profesionales de éxito en la Pedagogía.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Experiencias innovadoras de educación emprendedora con jóvenes participantes en programas de garantía juvenil

Youth Entrepreneurship Sustanaibility de Vélez-Málaga (YES) es un proyecto desarrollo en 2016 que ha sido financiado por el Fondo Social Europeo (FSE) a través de la Fundación INCYDE y el OALDIM, en el contexto del programa de Garantía Juvenil, y que ha tenido como principal objetivo, la puesta en marcha de itinerarios de captación y desarrollo del talento emprendedor que potencien la cultura del autoempleo en jóvenes del municipio de Vélez-Málaga (Málaga). A través de una metodología pedagógica basada en MasterClass, tutorías individuales, asesoramiento intensivo y el uso de las nuevas tecnologías, el participante ha recibido asesoramiento técnico de la mano de expertos-mentores especializados en diferentes disciplinas ligadas a la creación de empresas. Esta experiencia ahonda en las estrategias pedagógicas que sustentan el proyecto, así como los resultados obtenidos, en base a las metodologías utilizadas para llevarlo a cabo.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Yra1-bound RNA–DNA hybrids cause orientation-independent transcription– replication collisions and telomere instability

R loops are an important source of genome instability, largely due to their negative impact on replication progression. Yra1/ALY is an abundant RNA-binding factor conserved from yeast to humans and required for mRNA export, but its excess causes lethality and genome instability. Here, we show that, in addition to ssDNA and ssRNA, Yra1 binds RNA–DNA hybrids in vitro and, when artificially overexpressed, can be recruited to chromatin in an RNA– DNA hybrid-dependent manner, stabilizing R loops and converting them into replication obstacles in vivo. Importantly, an excess of Yra1 increases R-loop-mediated genome instability caused by transcription–replication collisions regardless of whether they are codirectional or head-on. It also induces telomere shortening in telomerase-negative cells and accelerates senescence, consistent with a defect in telomere replication. Our results indicate that RNA–DNA hybrids form transiently in cells regardless of replication and, after stabilization by excess Yra1, compromise genome integrity, in agreement with a two-step model of R-loop-mediated genome instability. This work opens new perspectives to understand transcription-associated genome instability in repair-deficient cells, including tumoral cells.European Research Council ERC2014 AdG669898 TARLOOPMinisterio de Economía y Competitividad BFU2016-75058-PJunta de Andalucía PA12- BIO123

Could combat stress affect journalists' news reporting? A psychophysiological response

Covering war conflicts may compromise the psychological and physical health of journalists because chronic exposure to these environments has been related to depression, memory dissociative processes, and post-traumatic stress disorder; however, acute effects have not been studied yet. Thus, a combat simulation was carried out replicating actual warfare scenarios, including personnel and equipment. Psychophysiological response, memory, and information-processing were analysed of 40 professional soldiers (21 males and 19 females) and 19 journalists (12 males and 7 females) with international experience in current conflict areas such as Afghanistan, Iraq, Bosnia and Herzegovina, and Kosovo, in relation to their experience of a combat intervention. A significant increase (p < 0.05) in metabolic, muscular, cardiovascular, and cortical and psychological anxiety response, as well as a decrease in memory accuracy directly after and 24 h and 72 h post-combat were found; these modifications were modulated by the nature of the stimulus. Journalists presented higher cognitive and memory impairment than soldiers, resulting in a press reporting of real events accuracy of only 27%