Experimental validation of an optical and thermal model of a Linear Fresnel Collector

2nd European Conference on Polygeneration – 30th March 1st April, 2011– Tarragona, SpainThis paper describes the design and validation of a mathematical model for a solar Fresnel collector. The function of the model is to simulate the optical and thermal dynamics of a Fresnel system for heating water. The model is validated using real data gathered from a cooling plant with double effect absorption chiller located in the School of Engineering University of Seville, Spain (Experimental cooling plant is also described in the paper). Comparison of calculated and plant measured data shows that the error is lower than 3% in the optical model and within 7% in the thermal model. The model uses a new approach to include a solar tracking mirror mechanism in one axis. This tracking has been designed to maximise the reception of available solar radiation by the absorption pipe. The thermal model used is based around classical models for solar receivers and it is validated with real operating data gathered from a supervisor system. The Fresnel model has been designed with sufficient flexibility to consider different geometries and thermal parameters, and may be used to simulate the performance of a proposed Fresnel collector system at any location

New simulations to qualify eutectic lithium-lead as breeder material

Pb17Li is today a reference breeder material in diverse fusion R&D programs worldwide. One of the main issues is the problem of liquid metals breeder blanket behavior. The knowledge of eutectic properties like optimal composition, physical and thermodynamic behavior or diffusion coefficients of Tritium are extremely necessary for current designs. In particular, the knowledge of the function linking the tritium concentration dissolved in liquid materials with the tritium partial pressure at a liquid/gas interface in equilibrium, CT =f(PT ), is of basic importance because it directly impacts all functional properties of a blanket determining: tritium inventory, tritium permeation rate and tritium extraction efficiency. Nowadays, understanding the structure and behavior of this compound is a real goal in fusion engineering and materials science. Atomistic simulations of liquids can provide much information; not only supplementing experimental data, but providing new tests of theories and ideas, making specific predictions that require experimental tests, and ultimately helping to a deeper understandin

Monitoring and forecasting usability indicators: a business intelligence approach for leveraging user-centered evaluation data

Monitoring performance indicators has become a main concern for most organizations today. While much attention has been paid to developing economic, bioinformatics, health, and social media dashboards, little or no attention has been devoted to monitoring and forecasting usability indicators. This can be of interest for analyzing the degree of perceived satisfaction and usability of interactive software products designed or just developed, being also useful as general strategic indicators in human-centered organizations. This paper presents an approach including main measures, Key Performance Indicators, trends, and forecasts to deal with usability information over time and produce new knowledge based on historical data. Also, an instance has been implemented, including data obtained from real software evaluations. Target users have evaluated the approach to validate its suitability, obtaining successful usability results that denote the adequacy of the approach presentedThis work was partially supported by the Spanish Research Agency [grant numbers TED2021-129381B-C21 and PID2021- 122270OB-I00

Intensidad tecnológica y características del empleo en el sector servicios

A partir de las peculiaridades que la relación tecnología-productividad-empleo\ud presenta en las actividades terciarias, este documento de trabajo realiza una primera\ud aproximación a la influencia ejercida por la intensidad tecnológica sobre las\ud características y comportamientos laborales de las diferentes ramas de servicios en\ud España. Para ello, y tras calcular un indicador de intensidad tecnológica basado en el\ud contenido tecnológico de los inputs intermedios, se desarrollan tres análisis distintos:\ud características de los puestos de trabajo, rasgos de los trabajadores integrados y\ud participación en los procesos de cambio estructural verificados en los servicios. Las\ud conclusiones alcanzadas apuntan hacia la existencia de una profunda diferenciación\ud laboral entre las ramas de alta y media intensidad, de un lado, y las de baja, por otro.\ud Las actividades pertenecientes a los dos primeros grupos presentan mayores\ud requerimientos de cualificaciones laborales, una mayor tasa de feminización y una\ud distribución por edades acentuada sobre los tramos intermedios. Además, se asocian con\ud procesos de trabajo más flexible y mejores condiciones de trabajo. Por último, las\ud actividades de media y alta intensidad son las que aparecen liderando los procesos de\ud reestructuración sectorial y de cualificaciones

Different papillomaviruses have different repertoires of transcription factor binding sites: convergence and divergence in the upstream regulatory region

BACKGROUND: Papillomaviruses (PVs) infect stratified squamous epithelia in warm-blooded vertebrates and have undergone a complex evolutionary process. The control of the expression of the early ORFs in PVs depends on the binding of cellular and viral transcription factors to the upstream regulatory region (URR) of the virus. It is believed that there is a core of transcription factor binding sites (TFBS) common to all PVs, with additional individual differences, although most of the available information focuses only on a handful of viruses. RESULTS: We have studied the URR of sixty-one PVs, covering twenty different hosts. We have predicted the TFBS present in the URR and analysed these results by principal component analysis and genetic algorithms. The number and nature of TFBS in the URR might be much broader than thus far described, and different PVs have different repertoires of TFBS. CONCLUSION: There are common fingerprints in the URR in PVs that infect primates, although the ancestors of these viruses diverged a long time ago. Additionally, there are obvious differences between the URR of alpha and beta PVs, despite these PVs infect similar histological cell types in the same host, i.e. human. A thorough analysis of the TFBS in the URR might provide crucial information about the differential biology of cancer-associated PVs

Experimental Feeding and Growth of Turbot (Scophthalmus maximus L.) from 0.5 To 2.7 Kg in Galicia (NW Spain)

Two groups of turbot, Scophthalmus maximus L., of 0.5 and 1.2 kg initial mean weight were fed a semimoist diet containing fish, fish meal and vitamin-mineral complex. The trial was carried out in tanks of 16 cubic meters, for aperiod of a year. Resul ts on feed conversion index and growth in weight are give

Assessing the feeding ecology of three sympatric squids Illex argentinus, Doryteuthis gahi and Onykia ingens off the Patagonian by combining stomach content and stable isotopic analysis

The Ommastrephidae Illex argentinus, the Loliginidae Doryteuthis gahi and the Onychoteuthidae Onikya ingens are squid species coexisting in the south part of the Patagonian Shelf, interacting for similar feeding resources. In the present study, we analyzed the feeding ecology, trophic position and trophic relationships of these three species by combining stomach content and stable isotopic approximations. In particular, stomach content and isotopic analysis were carried out on 20 D. gahi, 20 I. argentinus and 21 O. ingens collected from May 6th and 8th 2013 at depths between 147 and 220 m. The results indicated that the feeding habits of small and larger squids were different in the three species. The two main prey species for small D. gahi individuals were the euphausid Euphausia sp. and the amphipod Eutemisto gaudichaudi, and the main prey for larger D. gahi individuals were a fish and the Munididae Munida subrugosa. The main prey group of small I. argentinus individuals was the amphipod E. gaudichaudi and the myctophid fish, and the main prey for larger size I. argentinus individuals were the paralepididae Arctozenus risso and the Notothenidae Patagonotothen ramsayi, secondly by the squid group. Small O. ingens individuals fed on Micromesistius australis and Notophysis marginata while larger O. ingens individuals fed on Lampanyctus australis and Notoscopelus sp. D. gahi showed higher δ15N values than the other two species and small and larger D. gahi individuals showed similar isotopic values. The δ15N values of I. argentinus and O. ingens were higher for larger individuals. Finally, D. gahi differed in its δ13C values from I. argentinus and O. ingens and the less depleted δ13C values were found in the larger in D. gahi individuals. The results indicate that the three squid species preyed on organisms with similar trophic position, but due to their voracity and their active predation on similar trophic resources, small size individuals segregate their trophic niche from the larger ones. It is important to note that the δ13C values revealed that larger D. gahi individuals had a different distribution in the water column, which probably is a response of the reproductive activity of mature squid near to the surface water.Universidad Nacional Autónoma de Méxic

Synthesis and Electrocatalytic Properties of H2SO4-Induced (100) Pt Nanoparticles Prepared in Water-in-Oil Microemulsion

The increasing number of applications for shape-controlled metal nanoparticles (NPs) has led to the need for easy, cheap, and scalable methodologies. We report the synthesis of (100) preferentially oriented Pt NPs, with a particle size of 9 nm, by using a water-in-oil microemulsion method. The specific surface structure of the NPs is induced by the presence of H2SO4 in the water phase of the microemulsion. Interestingly, the results reported herein show how increasing amounts of H2SO4 lead to the formation of Pt NPs containing a larger amount of (100) sites on their surface. This preferential surface orientation is confirmed electrochemically by using the so-called hydrogen adsorption/desorption process. In addition, transmission electron microscopy measurements confirm the presence of cubic-like Pt NPs. Finally, the electrocatalytic properties of the Pt NPs are evaluated towards ammonia and CO electro-oxidations, which are (100) structure-sensitive reactions.This work has been financially supported by the MCINN-FEDER (Spain) (project CTQ 2010-16271), Generalitat Valenciana (project PROMETEO/2009/045) and in part by NASA-URC Grant No. NNX10AQ17A and NSF-NSEC Center for Hierarchical Manufactur-ing Grant No. CHM-CMMI-0531171. R. M-R is grateful to the Becas Iberoamérica, Santander Universidades-España 2012 and PR-LSAMP Bridge to Doctorate Fellowship programs