CFD model-based analysis and experimental assessment of key design parameters for an integrated unglazed metallic thermal collector façade

Active façade systems incorporating solar thermal collectors currently offer very promising energetic solutions. From among the available systems, a simple solution is the unglazed heat collector for potential integration in low-temperature applications. However, when adopting system definitions, the modification of some design parameters and their impact has to be fully understood. In this study, the case of an unglazed collector integrated into a sandwich panel is assessed and a specific analysis is performed for a proper assessment of the influence of key design parameters. Based on that case study of the real built system, a CFD model is developed and validated and a parametric assessment is then performed, by altering the configurations of both the panel and the hydraulic circuit. In this way, the potential of each measure to harness solar energy can be evaluated and each parameter with its different level of impact can be highlighted, to identify those of higher relevance. A characterization of the real solution completes the study, by providing the efficiency curves and the total energy collected during the experimental campaign. The maximum estimate of the efficiency of a 6 m2 façade was within a range between 0.47 and 0.34 and the heat loss factor was between 4.8 and 7.5. The case study exercises reveal the real energy efficiency and solar production patterns. There was also an opportunity to consider significant improvements to increase the output of the active façade. The main conclusions concerned the different criteria that improved the definition of the system and greater comprehension of alternative designs that may be integrated in the underlying concept.The authors are grateful to the Basque Government for fundingthis research through projects IT781-13 and IT1314-19 and to allthose involved in the different stages for their guidance andinvaluable help.The authors would also like to thank all those companies andresearchers participating in the BASSE project for their stronginvolvement during that research. Results from BASSE project haveinspired present research. The BASSE project received funding fromthe European Union, RFCS Program, Research Fund for Coal and Steel project Building Active Steel Skin (BASSE, Grant Agreement noRFSR-CT-2013-00026

Main Variables Affecting a Chemical-Enzymatic Method to Obtain Protein and Amino Acids from Resistant Microalgae

he development of microalgae uses requires further investigation in cell disruption alternatives to reduce the costs associated to this processing stage. This study aimed to evaluate the main variables affecting an extraction method to obtain protein and amino acids from microalgae. The method was based on a sequential alkaline-enzymatic process, with separate extractions and noncontrolled pH, and was applied to fresh biomass of a resistant species. The processed microalgae were composed of a consortium with Nannochloropsis sp. as predominant species. After the optimization of the pH of the alkaline reaction, the effect of the time of the alkaline reaction (30-120min), the time (30-120min) and temperature (40-60 degrees C) of the enzymatic reaction, and the biomass concentration (50-150mgml(-1)), on the extraction yields of protein and free amino nitrogen (FAN) and on the final concentration of protein in the extract, was studied using a response surface methodology. Even though all the variables and some interactions among them had a significant effect, the biomass concentration was the most important factor affecting the overall process. The results showed relevant information about the different options in order to maximize not only the response variables individually but also different combinations of them. Assays with optimized values reached maximum yields of 80.3% and 1.07% of protein (% of total protein) and FAN (% of total biomass), respectively, and a protein concentration in the extract of 15.2mgml(-1). The study provided the essential information of an alternative approach to obtain protein and amino acids from fresh biomass of resistant microalgae with a high yield, also opening perspectives for further research in particular aspects

Paleoecología de medios húmedos: el aporte de los microfósiles no polínicos

International audienceLos medios húmedos se comportan como auténticos ecosistemas, existiendo en ellos una componente abiótica y una componente biótica, que interrelacionan entre ellas interna y externamente, para definir diferentes tipos de nichos ecológicos que vienen fundamentalmente determinados por las características del agua. De manera genérica, éstos pueden subdividirse en dos tipos: medios oligotróficos y eutróficos , existiendo alternativas intermedias de tipo mesotrófico. Los estudios paleoecológicos permiten conocer la evolución temporal de los medios húmedos a través de los llamados microfósiles no polínico

Patrón temporal de movimientos del mero Epinephelus morio en la plataforma continental norte de la Península de Yucatán, México

Los movimientos estacionales del mero Epinephelus morio en la plataforma continental de Yucatán, son un elemento muy sensible en el manejo de la pesquería de este recurso que actualmente se encuentra sobreexplotado. En este trabajo se estima el patrón de movimientos de la población utilizando un modelo dinámico espacial. Se estimaron tasas de flujo de individuos entre áreas adyacentes considerando explícitamente la estructura de la población (juveniles, preadultos y adultos). El modelo fue aplicado utilizando información de captura por unidad de esfuerzo y distribuciones de frecuencias de longitud de la flota mediana mexicana que operó en la zona durante 1973, correspondiente a la época de las más altas capturas históricas. Se consideró capturabilidad variable con la talla, tiempo y zona así como mortalidad natural variable con la edad. Los resultados muestran patrones temporales de movimientos diferenciados por sector de población. Movimientos asociados a concentraciones de adultos fueron encontrados entre invierno y primavera en el centro y oriente de la plataforma continental, en profundidades de 35 a 60 m, mientras que el movimiento de los preadultos y juveniles fue en sentido contrario dirigiéndose hacia zonas más someras. En primavera-verano la población se desplaza hacia la zona occidental de la plataforma continental. Se detectó una mayor dinámica en adultos que en juveniles, sin embargo, se encontraron movimientos importantes de juveniles hacia el norte de la plataforma continental y frente a las zonas de Dzilam de Bravo-Río Lagartos. Los resultados muestran la importancia de esta información en la orientación de medidas de manejo como la exploración de áreas marinas protegidas o zonas de exclusión a la pesca que permitan la recuperación de la población

Paleoambiente y antropizacion en los Pirineos de Navarra durante el Holoceno medio (VI-IV milenios cal. BC) : una perspectiva palinologica

International audienceEl estudio palinológico de los yacimientos arqueológicos de Abauntz, Aizpea y Zatoya junto con el de las turberas de Atxuri, Belate, Quinto Real y Artxilondo, aporta información sobre los primeros indicios del impacto humano en el paisaje de los Pirineos navarros. Durante el Neolítico antiguo, los procesos de deforestación fueron poco signifi cativos, aumentando sus repercusiones durante el V milenio cal BC. Desde este período, los procesos de antropización son mucho más marcados, posiblemente como consecuencia de diferentes formas de explotación del medio (ganadería y agricultura)

Nutrición en el enfermo con fibrosis quística

La fibrosis quística es una enfermedad que se asocia a una mutación de un gen localizado en el brazo largo del cromosoma 7. Esta enfermedad multisistémica afecta especialmente a los pulmones y al páncreas exocrino, lo cual supone el trastorno más influyente en la nutrición de estos pacientes. Generalmente, la suplementación con enzimas pancreáticas es necesaria como elemento terapéutico. La prevalencia de diabetes en esta enfermedad aumenta con la edad, mientras que la afectación hepática clínica es menos frecuente y otras complicaciones intestinales como el ileomeconial, el reflujo gastroesofágico o la obstrucción del intestino distal pueden condicionar también la malnutrición. La prevalencia de la desnutrición en los pacientes con fibrosis quística es elevada, aunque variable, y se asocia directamente con el estado pulmonar y la supervivencia. La terapia nutricional ha adquirido gran importancia ya que se asocia con un mejor crecimiento y mejora o estabilización de la función pulmonar, por lo que debe ser una parte integral del tratamiento de estos pacientes

Endothelial cell and hemostatic activation in relation to cytokines in patients with sepsis

Sepsis is commonly associated with disturbances of the hemostatic balance. Most of the pathophysiological changes in sepsis are caused by endotoxin acting directly through endothelial injury or indirectly through release of cytokines with procoagulant effects. The relation between cytokines and hemostatic parameters was assessed in 32 patients with sepsis. Prothrombin fragment 1+2 (F1+2), thrombin-antithrombin III complexes (TAT), tissue type plasminogen activator (t-PA) functional and antigen, plasminogen activator inhibitor-1 (PAI-1), plasminalpha2-antiplasmin complexes (PAP), D-Dimer, thrombomodulin (TM) and von Willebrand factor (vWF) were measured in patients and in 30 healthy subjects. The levels of cytokines TNF-alpha and interleukin-6 (IL-6) also were determined. A significant increase of F1+2, TAT, PAI-1, PAP, and D-Dimer was observed in septic patients as compared with controls (p<0.0001), whereas t-PA activity was significantly reduced (p<0.01). The markers of endothelial cell activation TM, vWF, and t-PA antigen also were elevated significantly as compared with the control group (p<0.01). Finally, we found a marked increase of TNF-alpha and IL-6 (p<0.0001). Whereas the increase of cytokine levels could be partially responsible for the hemostatic activation, it did not correlate with markers of endothelial activation in patients with sepsis

The loyalty of young residents in an island destination: An integrated model.

This paper investigates the factors that influence the loyalty of young residents as tourists in their home destination in the context of domestic tourism. The interest in studying the loyalty of this particular population segment stems from their consumption potential, their influence, and for the triple role they can play as tourists in the destination, as residents in the destination and as collaborators with local tourism companies. The setting for this study is one of growing domestic tourism in a destination made up of islands, the Canary Islands (Spain). The importance of this kind of research for island destinations arises from the negative impacts of tourism that island destinations suffer more than others, often with negative repercussions on loyalty. This paper studies the role of tourism companies, the product, the place and the young residents themselves in the formation of loyalty. A sample of 678 young residents from the Canary Islands responded to an ad hoc questionnaire of 22 items. The descriptive analysis highlights that young residents value to varying degrees all the variables included in the model (tourism companies, place, product and tourist variables). The discriminant analysis shows that there are no significant differences in the perceptions of young residents according to gender, island of residence or the number of trips made within the destination, which confirms the generational nature of the study and the possibility of extrapolating the results. Using the causal model proposed, the formation of loyalty among young residents is explained. In this model, the variables related to the company and the product hardly influence loyalty formation among young residents when these variables are integrated into the same model with place variables (identity, attachment and familiarity). These variables initiate the chain of cause and effect that culminates in the formation of satisfaction and loyalty among tourists, relegating company and product variables to the background

Effects of introgressed 4Nv Aegilops ventricosa chromosome on yield and yield components in bread wheat.

Effects of introgressed 4Nv Aegilops ventricosa chromosome on yield and yield components in bread whea

Palynologie et histoire des activités humaines en milieu montagnard. Bilan provisoire des recherches et nouvelles orientations méthodologiques sur le versant nord des Pyrénées

International audienceDans l'étude des relations environnement / sociétés en milieu montagnard, la palynologie se positionne aujourd'hui comme une discipline incontournable offrant la possibilité d'aborder la longue durée des processus d'anthropisation. Un examen critique de l'évolution de cette discipline par rapport à la problématique de l'anthropisation peut être mené à partir de l'exemple pyrénéen. S'il ressort que les acquis sont nombreux, ils ne s'accordent pas toutefois systématiquement aux nouvelles demandes formulées par un contexte scientifique résolument orienté vers l'interdisciplinarité. La variabilité des échelles d'analyses temporelles et spatiales constitue un écueil important, mais celui-ci semble pouvoir être contourné par le développement de nouvelles approches paléoécologiques reposant sur des analyses intégrées ainsi que sur la mise en place de référentiels fonctionnels. Nous présentons ici brièvement les résultats de quelques tentatives menées sur le territoire pyrénéen dans le cadre de différents programmes de recherches