On track for solar grade silicon through a Siemens process-type laboratory reactor: operating conditions and energy savings

Polysilicon cost impacts significantly on the photovoltaics (PV) cost and on the energy payback time. Nowadays, the besetting production process is the so called Siemens process, polysilicon deposition by chemical vapor deposition (CVD) from Trichlorosilane. Polysilicon purification level for PV is to a certain extent less demanding that for microelectronics. At the Instituto de Energía Solar (IES) research on this subject is performed through a Siemens process-type laboratory reactor. Through the laboratory CVD prototype at the IES laboratories, valuable information about the phenomena involved in the polysilicon deposition process and the operating conditions is obtained. Polysilicon deposition by CVD is a complex process due to the big number of parameters involved. A study on the influence of temperature and inlet gas mixture composition on the polysilicon deposition growth rate, based on experimental experience, is shown. Moreover, CVD process accounts for the largest contribution to the energy consumption of the polysilicon production. In addition, radiation phenomenon is the major responsible for low energetic efficiency of the whole process. This work presents a model of radiation heat loss, and the theoretical calculations are confirmed experimentally through a prototype reactor at our disposal, yielding a valuable know-how for energy consumption reduction at industrial Siemens reactorsPostprint (published version

Teacher Emotion Inventory: validation in a sample of Spanish teachers

Background: Teacher Emotion Inventory (TEI) scale is an instrument that evaluates discrete emotions experienced by teachers in the teaching-learning process. The aim of this study was to examine the psychometric properties of the brief Spanish version of the Teacher Emotion Inventory scale (TEI-BSV) using a sample of 567 teachers (65.5% women), aged between 25 and 65 years (M= 46.04; SD= 9.09). Methods: After adaptation through back-translation, the teachers completed a battery of tests included in the TEI-BSV: an emotional intelligence questionnaire, two subjective well-being scales, a burnout scale and a scale on engagement. Results: The data revealed adequate internal consistency of the TEI-BSV subscales, and exploratory and confirmatory factor analyses provided evidence that the TEI-BSV has a four-factor structure with good adjustment, as opposed to the original five-factor structure proposed. There was evidence of convergent validity of the TEI-BSV, as well as criterion and incremental validity. Conclusions: The TEI-BSV could be a useful instrument for the ecological assessment of teachers' discrete emotions in the context of their workplacAntecedentes: La escala Teacher Emotion Inventory (TEI) es un instrumento que evalúa emociones discretas experimentadas por el profesorado en el proceso de enseñanza-aprendizaje. El objetivo de este estudio es examinar las propiedades psicométricas de la versión breve española de la escala Teacher Emotion Inventory (TEI-BSV) en una muestra de 567 profesores (65.5% son mujeres), con edades comprendidas entre 25 y 65 años (M= 46.04; DT= 9.09). Método: Tras su adaptación mediante traducción inversa, el profesorado completó una batería que incluía el TEI-BSV, un cuestionario de inteligencia emocional, dos escalas de bienestar subjetivo, una escala sobre burnouty una escala sobre engagement. Resultados: Los resultados mostraron una consistencia interna adecuada de las subescalas del TEI-BSV. Los análisis factoriales (exploratorio y confirmatorio) proporcionaron pruebas de que el TEI-BSV tiene una estructura de cuatro factores con un buen ajuste, frente a la estructura de cinco factores original. Se han hallado evidencias de validez convergente, así como de validez criterial e incremental del TEI-BSV. Conclusiones: el TEI-BSV podría ser una herramienta útil para la evaluación ecológica de las emociones discretas del profesorado en su contexto laboral

On track for solar grade silicon through a siemens process-type laboratory reactor: operating conditions and energy savings

Polysilicon cost impacts significantly on the photovoltaics (PV) cost and on the energy payback time. Nowadays, the besetting production process is the so called Siemens process, polysilicon deposition by chemical vapor deposition (CVD) from Trichlorosilane. Polysilicon purification level for PV is to a certain extent less demanding that for microelectronics. At the Instituto de Energía Solar (IES) research on this subject is performed through a Siemens process-type laboratory reactor. Through the laboratory CVD prototype at the IES laboratories, valuable information about the phenomena involved in the polysilicon deposition process and the operating conditions is obtained. Polysilicon deposition by CVD is a complex process due to the big number of parameters involved. A study on the influence of temperature and inlet gas mixture composition on the polysilicon deposition growth rate, based on experimental experience, is shown. Moreover, CVD process accounts for the largest contribution to the energy consumption of the polysilicon production. In addition, radiation phenomenon is the major responsible for low energetic efficiency of the whole process. This work presents a model of radiation heat loss, and the theoretical calculations are confirmed experimentally through a prototype reactor at our disposal, yielding a valuable know-how for energy consumption reduction at industrial Siemens reactors

Heat losses in a CVD reactor for polysilicon: comprehensive model and experimental validation

This work addresses heat losses in a CVD reactor for polysilicon production. Contributions to the energy consumption of the so-called Siemens process are evaluated, and a comprehensive model for heat loss is presented. A previously-developed model for radiative heat loss is combined with conductive heat loss theory and a new model for convective heat loss. Theoretical calculations are developed and theoretical energy consumption of the polysilicon deposition process is obtained. The model is validated by comparison with experimental results obtained using a laboratory-scale CVD reactor. Finally, the model is used to calculate heat consumption in a 36-rod industrial reactor; the energy consumption due to convective heat loss per kilogram of polysilicon produced is calculated to be 22-30 kWh/kg along a deposition process

An electroacoustic method for measuring airflow resistivity of porous sound-absorbing materials

[EN] In this paper, a method for measuring the airflow resistivity of air-saturated porous sound-absorbing materials is presented. The method is based on a modification of the previous device developed by Dragonetti et al. The approach used in the present work involves a cavity and a Helmholtz resonator that are coupled through a loudspeaker so that the complete system behaves as a fourth-order symmetrical band-pass loudspeaker system. After a straightforward calibration, the airflow resistivity of a material sample is indirectly estimated from the direct measurement of the total electric impedance at the loudspeaker connection terminals. In this way, the use of microphones is not necessary, which makes its implementation very simple and inexpensive. Experimental results obtained with the present method agree well with those obtained through a standardized method as long as the values of the material's airflow resistance are not too high. (C) 2019 Elsevier Ltd. All rights reserved.The authors would like to gratefully acknowledge the support of CONICYT-FONDECYT under Grant 1171110 and to the Vicerectorate of R+i+t at Univ. Politecnica of Valencia, Grant PAID0017.Alba, J.; Arenas, JP.; Rey Tormos, RMD.; Rodríguez-Vercher, J. (2019). An electroacoustic method for measuring airflow resistivity of porous sound-absorbing materials. Applied Acoustics. 150:132-137. https://doi.org/10.1016/j.apacoust.2019.02.009S13213715

Validación al castellano de la Body Responsiveness Connection Scale (Escala de Respuesta Corporal (ERC) en médicos internos del hospital San Rafael de Tunja en Colombia

The connection between mind and body refers to the process of self-regulation therapies designed to increase both physical and mental well-being. Objective: To determine the psychometric properties of the Body Responsiveness Connection Scale  in a population of medical interns and residents  at the San Rafael Hospital in the city of Tunja (Colombia). Material and methods: A translation and back translation of the Body Responseveness Connection Scale was performed. The instrument was applied to 112 resident physicians of the San Rafael de Tunja Hospital, between the ages of 18 and 35. The internal consistency of the instrument was analyzed using Cronbach’s α, and the test-retest reliability with intraclass correlation coefficient. Results: The average age of the participants was 23.5  years (SD ± 2.06 years), the majority were women. 38.4% came from public universities and 62.4% reported no additional activities in their free time. The internal consistency of the scale was 0.87. The correlation coefficient was greater than 0.6 in most of the items. Conclusions: The studied body response scale in health personnel presents psychometric properties similar to the original version, with adequate reliability and validity, which allow the evaluation of relevant aspects of body awareness and dissociation.La conexión entre mente y cuerpo hace referencia al proceso de terapias de autorregulación diseñadas para aumentar tanto el bienestar físico como el mental. Objetivo: Determinar las propiedades psicométricas de la Escala de Respuesta Corporal (ERC) en una población de médicos internos y residentes del hospital San Rafael, en la ciudad de Tunja (Colombia). Material y métodos: Se realizó una traducción y retro-traducción de la Body Responseveness Connection Scale. El instrumento fue aplicado a 112 médicos internos del Hospital San Rafael de Tunja, entre18 y 35 años. Se analizó la consistencia interna del instrumento mediante el test α Cronbach, y la fiabilidad test- retest con el coeficiente de correlación intraclase. Resultados: La edad promedio de los participantes fue de 23,5 años (DE ± 2,06 años), la mayoría fueron mujeres. El 38.4% provenían de universidades públicas y el 62,4% no realizaban actividades adicionales en su tiempo libre. La consistencia interna de la escala fue de 0,87. El coeficiente de correlación fue mayor de 0,6 en la mayoría de los ítems. Conclusiones: La Escala de Respuesta Corporal en personal de la salud presenta propiedades psicométricas similares a la versión original, con adecuada confiabilidad y validez, factores que permiten evaluar aspectos relevantes de conciencia y disociación corpora

Agrumes entiers dans les rations totales mélangeés pour brebis laitières méditerranéennes. Production et composition du lait

[Otros] Dans cette étude, 48 brebis en lactation, appartenant à 2 races méditerranéennes, la race Guirra (race autochtone rustique) ou la race Manchega (race mixte) ont été utilisées pour évaluer l¿effet de l¿inclu- sion de fruits d¿agrumes entiers (WCF) dans leurs rations. Quatre rations complètes ont été formulées pour être iso-énergétiques et iso-azotées. Elles se différenciaient par le taux d¿incorporation de WCF (0, 10, 20 et 30%) qui était substitué, sur une base matière sèche, à de l¿orge concassée ou à de la pulpe de betterave en pellets. La production et la composition du lait ont été mesurées une fois par semaine sur deux traites successives (matin et soir). La production de lait obtenue avec le group recevant 30% WCF a été supérieure de 12% à celle des autres groupes. De plus, on a observé une réduction du taux butyrique avec l¿inclusion de WCF. Elle était de 8,2; 7,95; 7,69 and 7,1 pour les groups recevant respectivement 0, 10, 20 et 30% de WCF (P<0,05). La teneur en protéines du lait a été maximale avec le group recevant 10% WCF (6,4%) et minimale avec celui ayant 30%WCF (6,0% ; P<0,05), car la teneur en caséine du lait a été la plus faible avec le groupe recevant 30%WCF (-0,3% par rapport aux groupes avec 0 et 10% de WCF; P< 0,05), tandis que la teneur en protéines solubles a été similaire pour tous les groupes (moyenne: 1,17%). Tout au long de la période expérimentale, on a observé une diminution de la production de lait standard (6%FCM) avec toutes les rations (-35% par semaine), mais il a été plus prononcé pour les groupes recevant 20% et 30% WCF que pour les autres. En conclusion, l¿incorporation de WCF pourrait contribuer à diminuer la dépendance vis à vis des céréales pour les brebis à haute production sans affecter les paramètres de production laitière ; mais d¿autres études relatives aux effets de WCF sur la condition corporelle et sur la capacité des animaux en lac- tation à mobiliser leurs réserves doivent être faites.[EN] A total of 48 lactating ewes, belonging to 2 different Mediterranean breeds Guirra (rustic native breed) and Manchega (mixed aptitude breed) were used to evaluate the effect of the inclusion of whole citrus fruits (WCF) in their rations. Four iso-energetic and iso-protein total mixed rations were formulated containing fresh WCF at 0, 10, 20 and 30% replacing dry-rolled barley and pelleted beet pulp on a DM basis. The milk yield and composition were obtained once a week at morning and afternoon milking. Total milk yield values observed for 30% WCF group were 12% higher than for the others. Also, a reduction of the milk fat content with the inclusion of WCF was observed, being 8.2, 7.95, 7.69 and 7.1% for 0, 10, 20 and 30% WCF groups (P<0.05). Milk protein content was maximum for ewes on 10% WFC ration (6.4%) and minimum for 30% WCF group (6.0%; P<0.05), due to the lower milk casein content of 30% WCF group (-0.3% respect to 0 and 10% WCF groups; P<0.05), while soluble protein content was similar for all the groups (mean: 1.17%). Throughout the experimental period, a reduction of 6% fat corrected milk (6%FCM) production was observed with all the rations (-35 ml per week), but it was steeper for 20 and 30% WCF groups than for the other 2 groups. In conclusion, WCF could contribute to diminishing dependence of high-milking ewes on grains without affecting the milk output, however further studies related to WCF effect on body condition and on the capacity of lactating animals to mobilize body reserves should be made.This study was subsidized by the Consejeria de Agricultura, Pesca y Alimentación of the Regional Government of Valencia, and by the project INIA CAL03-089. 6.Piquer Querol, O.; Rodríguez Garcia, M.; Blas Ferrer, E.; Cerisuelo, A.; Fernández Martínez, CJ.; Pascual Amorós, JJ. (2011). Whole citrus fruits in total mixed rations for Mediterranean milking ewes. Milk production and composition. Options Mediterraneennes. Serie A: Seminaires Mediterraneens. 99:251-258. http://hdl.handle.net/10251/147521S2512589

Characterization of New Sustainable Acoustic Solutions in a Reduced Sized Transmission Chamber

[EN] In order to assess the airborne sound insulation of a new material or building solution, access to standardized laboratories, large and expensive facilities, and a sample area of at least 10 m(2) are required. At the research and development stages of new sustainable acoustic materials for construction, it is not easy to make large sample areas available. Moreover, the financial investment in acoustic testing of materials during the research stage in standardized laboratories is excessive. In this work, the assessment of the airborne sound insulation of multi-layer partitions designed with new sustainable materials is presented. The assessed solutions are formed by green composite fiber boards as lightweight elements and a new material designed from sheep wool as absorbent material. The results of these 100% recyclable solutions are compared with lightweight element based solutions, which are commonly used for acoustic insulation. Characterization of those new sustainable solutions for building is leveraged in a reduced sized transmission chamber. The design, construction, and validation of this kind of laboratory are provided. This laboratory enables the assessment of the airborne sound insulation of a material in its research stage.This work was financially supported by the project BIA2013-41537-R (BIAEFIREMAT "Development of new eco-materials and sustainable constructive solutions based on the use of waste and renewable raw materials"), funded by the Spanish Ministry of Economy and Competitiveness and co-financed with funds from the European Regional Development Fund (ERDF), within the 2013 National RDI Programme Aimed at Society's Challenges.Rey Tormos, RMD.; Alba, J.; Rodríguez-Vercher, J.; Bertó Carbó, L. (2019). Characterization of New Sustainable Acoustic Solutions in a Reduced Sized Transmission Chamber. Buildings. 9(3). https://doi.org/10.3390/buildings9030060S9

Atroposelective synthesis of axially chiral naphthylpyrroles by a catalytic asymmetric 1,3-dipolar cycloaddition/aromatization sequence

A straightforward methodology for the enantioselective preparation of axially chiral 2-naphthylpyrroles has been developed. This protocol is based on a CuI/Fesulphos-catalyzed highly enantioselective 1,3-dipolar cycloaddition of an azomethine ylide followed by pyrrolidine alkylation and pyrrolidine to pyrrole oxidation. The mild conditions employed in the DDQ/blue light-mediated aromatization process facilitate an effective central-to-axial chirality transfer affording the corresponding pyrroles with high atroposelectivit