Fabrication and Characterization of Multiband Solar Cells Based on Highly Mismatched Alloys

Multiband solar cells are one type of third generation photovoltaic devices in which an increase of the power conversion efficiency is achieved through the absorption of low energy photons while preserving a large band gap that determines the open circuit voltage. The ability to absorb photons from different parts of the solar spectrum originates from the presence of an intermediate energy band located within the band gap of the material. This intermediate band, acting as a stepping stone allows the absorption of low energy photons to transfer electrons from the valence band to the conduction band by a sequential two photons absorption process. It has been demonstrated that highly mismatched alloys offer a potential to be used as a model material system for practical realization of multiband solar cells. Dilute nitride GaAs1-xNx highly mismatched alloy with low mole fraction of N is a prototypical multiband semiconductor with a well-defined intermediate band. Currently, we are using chemical beam epitaxy to synthesize dilute nitride highly mismatched alloys. The materials are characterized by a variety of structural and optical methods to optimize their properties for multiband photovoltaic devices

Evaluation of the effect of different insecticides on the survival and capacity of 2 Eretmocerus mundus Mercet to control Bemisia tabaci (Gennadius) populations

Two different experiments were carried out to evaluate three insecticides. In the 24 first one, the effect of two insecticides, methomyl and indoxacarb, on pupae and 25 adults of the whitefly Bemisia tabaci (Gennadius) parasitoid Eretmocerus mundus 26 Mercet was evaluated under laboratory and greenhouse conditions, using sweet 27 pepper (Capsicum annuum L.) plants. In the second experiment, oxamyl was 28 tested to study its effect on the ability of E. mundus to parasitize and control B. 29 tabaci in sweet pepper plants, using a greenhouse cage evaluation. Methomyl and 30 indoxacarb caused low mortality of E. mundus pupae (17.6 and 7.8% 31 respectively), although methomyl mortality was significantly higher. Methomyl 32 produced 100% mortality on E. mundus adults with fresh and 24 hour-old 33 residues on leaves, significantly higher than the mortality produced by indoxacarb 34 (values ranged from 43.9 to 34.4%). The harmful effect of methomyl persisted for 35 a long time (up to 60 days). The results of the experiment with oxamyl showed 36 that E. mundus controlled whitefly population, without significant interaction 37 between the presence of the parasitoid and insecticide on whitefly mortality. 38 Whitefly mortality in the presence of the parasitoid was 87.8%, significantly higher 39 than the mortality in the absence of E. mundus (59.3%). Oxamyl did not produce 40 a significant effect on the emergence of E. mundus adults. Application of the 41 products in IPM programs is discussed

Expanding ocean-monitoring capabilities in the Macaronesia with unmanned mobile platforms

The Macaronesia is a vast area playing a key role in the East boundary of the Central North-Atlantic ocean-circulation system. Despite a significant research activity in ocean monitoring for decades using a wide range of observing systems and methodologies, the area is still under-sampled, mainly due access and coverage constrains, as well as the observation sustainability. Ocean gliders offer a new approach in terms of capacity and sustainability, allowing undertake ocean-monitoring in spatiotemporal scales hitherto unavailable. The present work shows preliminary results from the latest mission with buoyancy-driven and surface ocean gliders in the area, whose main goal focuses on to improve and expand ocean observation capabilities strengthening glider endurance lines between archipelagos, as part of the global ocean-observation strategy conducted by the Marine & Maritime Network (R3M), as regional contribution directly aligned with European and international initiatives and strategies in the North Atlantic basin.Peer Reviewe

Brayton technology for Concentrated Solar Power plants: Comparative analysis of central tower plants and parabolic dish farms

[EN]Concentrated solar power plants intend to be key in the pool of renewable energy production technologies in the next future because of their versatility and high efficiency. In this work a comparative study between two promising technologies is developed. A central tower receiver surrounded by a heliostat field and a farm of parabolic dishes, both coupled to a hybrid Brayton cycle, are considered. Two power scales are surveyed (between 5 and 20 MW) at three different locations with quite different latitudes (between Sahara desert and medium European latitudes) and meteorological conditions. A modelling scheme developed by our group that allows to obtain the expected thermodynamic and thermo-economic plant records is applied. Key indicators like efficiency, net generated energy, levelized cost of electricity, and specific plant investment are calculated and analysed. Variability of natural gas prices and also land cost uncertainty are reflected on levelized cost of electricity range. Among the plants compared, minimum values are found within the interval [135–163] USD/MWh for central towers at the highest power considered and southern latitudes. In addition, the area needed for the installation of the plants and the influence of CO taxes is also analysed. Displayed cashflows show larger investment costs for central tower than for dish farms. Finally, those systems are put into the context of other concentrated solar power, other renewable, like wind or photovoltaic, and other conventional power plants.PC_TCUE18-20P_010. Universidad de Salamanca and Banco de Santande

Community structure of pelagic copepods in the eastern tropical Pacific Ocean during summer and autumn.

The Eastern Tropical Pacific Ocean (ETPO) is a region of interest for commercial fisheries but is subject to high oceanographic variability, which affects primary and secondary production. Because pelagic copepods contribute significantly to secondary productivity, they were investigated to examine community structure variation both temporally and spatially. Zooplankton samples were collected from August to December 2003 using a bongo net (333 µm in mesh size). Ninety-six zooplankton samples were analysed, recording 94 copepod species from orders Calanoida, Cyclopoida, Harpacticoida and Poecilostomatoida. The study area could be divided into six geographical zones based on the numerically dominant species. The oceanographic conditions were relatively stable during summer and autumn. Total copepod abundance was higher (47,096 to 62,681 ind.100 m-3) in stations near the coast, mostly in southern Baja California and the Gulf of Tehuantepec; the lowest densities were recorded towards the study area's oceanic regions. Similarly, ecological diversity was higher in zones influenced by tropical mass waters. The biogeographical affinity of copepod species was dominated by tropical species (75.5%), whereas subtropical and temperate species were far less abundant (15.7 and 8.6%, respectively).Versión del editor0,708

Francisco de Asís Cabrero: Vuelta al mundo en busca de la historia

Francisco de Asís Cabrero Torres-Quevedo (Santander 1912-Madrid 2005) completó su trayectoria profesional con la realización de un gran número de viajes internacionales. Estos itinerarios encerraban el propósito declarado de recopilar datos y experiencias para la realización de “el libro”, como él mismo lo llamaba, de historia de la arquitectura. Cabrero documentó sus andaduras por los cinco continentes mediante un importante número de fotografías. Estas fotografías, o más bien sus negativos, constituyen el grueso de la donación realizada en 2014 por la familia Cabrero al Archivo General de la Universidad de Navarra. En los viajes, que de por sí tienen un gran atractivo, se aprecia una maduración teórico-histórica en la mentalidad del propio Cabrero. En lo que respecta a la fotografía, despunta el hecho de que trascendiera al cuaderno de viaje y superara tradicional boceto arquitectónico como instrumento de representación principal para la toma de apuntes. Francisco Cabrero es modelo de arquitecto moderno que utiliza la imagen fotográfica como herramienta documental del viaje.Francisco de Asís Cabrero Torres-Quevedo (1912-2005) completed his career travelling around the world. These itineraries were proposed to collect data and experiences for the realization of “the book” –as he called it–, a history of architecture. Cabrero documented his adventures across the five continents through a large number of photographs. These pictures, or rather negatives, constitute the donation made in 2014 by the Cabrero family to the General Archive of the University of Navarra. On trips, which themselves are very interesting, we can see a theoretical and historical maturation in Cabrero own mentality. On photography, blunts the fact that overcome traditional architectural sketch as his primary representation and note taking. Francisco Cabrero is a model of modern architect who uses the photographic image as a documentary travelling tool

Amplificación del efecto destructivo de los desprendimientos rocosos por deslizamiento sobre suelos volcánicos (Tenerife y Madeira)

This work provides geomorphological and geotechnical observations on the amplification of the destructive behaviour of rock falls developed in rocky slopes with a soil rich in organic matter, which are both exposed to high rainfall regimes. The determinant factor of this process would be related to the low geotechnical quality that the organic matter gives to the soil, which experience a sudden change in its fabric related to the dynamic load, similar to those observed in the quick clays in the fjords of Norway

Hydrogen-free SiCN films obtained by electron cyclotron resonance plasma: a study of composition, optical and luminescent properties

The Electrochemical Society, Inc. 2007. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in Journal of the Electrochemical Society Vol. 154 Issue 4 (2007): H325-H33

Fitting the data from embryo implantation prediction: Learning from label proportions

Machine learning techniques have been previously used to assist clinicians to select embryos for human-assisted reproduction. This work aims to show how an appropriate modeling of the problem can contribute to improve machine learning techniques for embryo selection. In this study, a dataset of 330 consecutive cycles (and associated embryos) carried out by the Unit of Assisted Reproduction of the Hospital Donostia (Spain) throughout 18 months has been analyzed. The problem of the embryo selection has been modeled by a novel weakly supervised paradigm, learning from label proportions, which considers all the available data, including embryos whose fate cannot be certainly established. Furthermore, all the collected features, describing cycles and embryos, have been considered in a multi-variate data analysis. Our integral solution has been successfully tested. Experimental results show that the proposed technique consistently outperforms an equivalent approach based on standard supervised classification. Embryos in this study were selected for transference according to the criteria of the Spanish Association for Reproduction Biology Studies. Obtained classification models outperform these criteria, specifically reordering medium-quality embryos

BIORREMEDIACIÓN DE SUELOS CONTAMINADOS POR ORGANOCLORADOS MEDIANTE LA ESTIMULACIÓN DE MICROORGANISMOS AUTÓCTONOS, UTILIZANDO BIOSÓLIDOS

The present investigation evaluated the process of bioremediation of organochlorine pesticides in a soil of the agricultural airport "The Picacho" of Chinandega's Department, Nicaragua, in that there are registered big concentrations of toxafeno. The biostimulation technique was used in the bioremediation process, using biosolids as source of essential nutrients for the microorganisms. The experimental design consisted of 2 completely randomized blocks, each one with 3 experimental units, contemplating 6 microcosms of soil. To every treatment one added different proportions of biosolids establishing relations soil:biosolid of 71:29 and 77:23. On having finished the treatments percentages of remediation were obtained between 84 % and 69 % respectively. This demonstrates the efficiency of the biosolids as source of nutrients for the metabolic stimulation of autochthonous microorganisms in the process of bioremediation of soils contaminated with toxafeno.La presente investigación evaluó el proceso de biorremediación de plaguicidas organoclorados en un suelo del aeródromo agrícola “El Picacho” del Departamento de Chinandega, Nicaragua, en el que se registran grandes concentraciones de toxafeno. Se empleó la técnica de bioestimulación en el proceso de biorremediación, utilizando biosólidos como fuente de nutrientes esenciales para los microorganismos. El diseño experimental constó de 2 bloques completamente aleatorizados, cada uno con 3 unidades experimentales, contemplando 6 microcosmos de suelo. A cada tratamiento se agregó diferentes proporciones de biosólido estableciendo relaciones suelo: biosólido de 71:29 y 77:23. Al finalizar los tratamientos se obtuvieron porcentajes de remediación entre 84% y 69% respectivamente. Esto evidencia la efectividad de los biosólidos como fuente de nutrientes para la estimulación metabólica de microorganismos autóctonos en el proceso de biorremediación de suelos contaminados con toxafeno.