Measuring the transition to homogeneity with photometric redshift surveys

We study the possibility of detecting the transition to homogeneity using photometric redshift catalogs. Our method is based on measuring the fractality of the projected galaxy distribution, using angular distances, and relies only on observable quantites. It thus provides a way to test the Cosmological Principle in a model-independent unbiased way. We have tested our method on different synthetic inhomogeneous catalogs, and shown that it is capable of discriminating some fractal models with relatively large fractal dimensions, in spite of the loss of information due to the radial projection. We have also studied the influence of the redshift bin width, photometric redshift errors, bias, non-linear clustering, and surveyed area, on the angular homogeneity index H2 ({\theta}) in a {\Lambda}CDM cosmology. The level to which an upcoming galaxy survey will be able to constrain the transition to homogeneity will depend mainly on the total surveyed area and the compactness of the surveyed region. In particular, a Dark Energy Survey (DES)-like survey should be able to easily discriminate certain fractal models with fractal dimensions as large as D2 = 2.95. We believe that this method will have relevant applications for upcoming large photometric redshift surveys, such as DES or the Large Synoptic Survey Telescope (LSST).Comment: 14 pages, 14 figure

Manage entropy in Architectural Projects: assuming commitments and ordering diversity

It was primary to transfer to the student the importance of his own responsibility on the project, transcending the usual condition of mere academic practice in the school. Their projects are already real actions to transform the reality from the moment in which are the product of a responsible and critical thinking. To the regular development of the Subject of Architectural Projects with theoretical classes and collective corrections in Workshop of Projects, it was incorporated a series of methodologies to activate the individual and collective learning. The project critically acts on city model, proposes an architectural intervention with transformative will and the classroom becomes a social space where individual engagements and collective engagements are added. This dialectic with reality was concluded with the exhibition of projects, which the students explained to the neighbours as the end of the course, first in school and finally in their civic center.Fue primordial transferir al estudiante la importancia de su propia responsabilidad sobre el proyecto, trascendiendo la habitual condición de mera práctica escolar en la Escuela. Sus proyectos son ya verdaderas acciones para transformar la realidad desde el momento mismo en que son el producto de un pensamiento crítico y responsable. Al desarrollo habitual de la Asignatura de Proyectos Arquitectónicos con clases teóricas y correcciones colectivas en Taller de Proyectos se incorporan una serie de metodologías para activar individual y colectivamente el aprendizaje. El proyecto actúa críticamente sobre el modelo de ciudad, propone una intervención arquitectónica con voluntad transformadora y el aula se convierte en un espacio social donde se suman compromisos individuales y compromisos colectivos. Esta dialéctica con la realidad se concluyó con la exposición de los proyectos realizados, que los estudiantes explicaron ante los vecinos del barrio como final de curso, en la Escuela y en su Centro Cívico

Reinforcing the link between the double red clump and the X-shaped bulge of the Milky Way

The finding of a double red clump in the luminosity function of the Milky Way bulge has been interpreted as evidence for an X-shaped structure. Recently, an alternative explanation has been suggested, where the double red clump is an effect of multiple stellar populations in a classical spheroid. In this Letter we provide an observational assessment of this scenario and show that it is not consistent with the behaviour of the red clump across different lines of sight, particularly at high distances from the Galactic plane. Instead, we confirm that the shape of the red clump magnitude distribution closely follows the distance distribution expected for an X-shaped bulge at critical Galactic latitudes. We also emphasize some key observational properties of the bulge red clump that should not be neglected in the search for alternative scenarios

Comportamiento en fluencia de un material compuesto de matriz metálica Al6061-15 vol % SiCw pulvimetalúrgico

Se ha realizado un estudio de las propiedades en fluencia del material compuesto pulvimetalúrgico Al6061-15 vol % SiCw. Su comportamiento se ha comparado con el de la aleación Al6061 pulvimetalúrgica y la aleación Al6061 de colada. El comportamiento del material pulvimetalúrgico sin reforzar mejora respecto al del material de colada. Al mismo tiempo, el del material compuesto mejora respecto al comportamiento del material pulvimetalúrgico sin reforzar. Se consideran dos factores microestructurales como los principales responsables de la mejora de las propiedades en fluencia de este material compuesto. Por un lado, las partículas de Al2O3 de tamaño nanométrico y, por otro, las partículas de fibra corta cerámicas de SiC de tamaño micrométrico. Aunque ambos tipos de partículas dan lugar a un efecto de refuerzo similar, los mecanismos intrínsecos asociados a la presencia de estas partículas tienen una naturaleza diferente debido a la diferencia en la escala microestructural.Peer reviewe

Multi-technology battery storage system for optimal demand-side management

Demand-side management (DSM) provides additional system flexibility for the electric energy environment. To enable the spread of DSM policies the use of automatic systems combined with a local battery energy storage system (BESS) is proposed. Following this statement, it has been developed and tested a 50 kVA low-cost multi-technology energy storage system, with a novel converter topology that permits the integration of multiple battery types or aging. It consists of a 50 kVA bidirectional three-level AC/DC converter for grid connection which feeds five 10 kW isolated bi-directional DC/DC battery converters, based on SiC and Si MOSFETs. The development leads in a pick-and-place system, adding interoperability, ease of connection and modularity

The short term influence of aboveground biomass cover crops on C sequestration and β-glucosidase in a vineyard ground under semiarid conditions

© 2014 Ministerio de Agricultura Pesca y Alimentacion. All Rights Reserved. Tillage and semiarid Mediterranean climatic conditions accelerate soil organic matter losses in Spanish vineyards. Previous studies showed that cover crops can increase soil organic carbon (SOC) in Mediterranean vineyards. The objectives of this study were to evaluate the influence of two different cover crops in the short term on soil C sequestration in a semiarid vineyard and to study the potential use of both β-glucosidase enzimatic activity (GLU) and the GLU/SOC ratio in order to assess the SOC increase. The experiment was carried out in a cv. Tempranillo (Vitis vinifera L.) vineyard on a Oxyaquic Xerorthent soil in Rioja winegrowing region (NE, Spain). The experimental design was established in 2009 with three treatments: conventional tillage; sown barley cover crop (Hordeum vulgare, L.); sown Persian clover cover crop (Trifolium resupinatum L.). Carbon in the aboveground biomass with each cover crop was monitored. Soil was sampled in June 2011 and June 2012, and SOC, GLU and the GLU/SOC ratio were determined. After 3 years both cover crops increased SOC at soil surface with C sequestration rates of 0.47 and 1.19 t C ha–1 yr–1 for BV and CV respectively. GLU and GLU/SOC ratio increased in both cover crops at 0-5 cm soil depth. The C sequestration rates and GLU were related to the cover crops aboveground biomass. In consequence, in semiarid vineyards under cover crops GLU could be an appropriate indicator to asses the increase of SOC and the soil quality improvement in the short-term (2-3 years).This study was supported by the Spanish Ministry of Science, INIA and European Social Fund through project INIA-RTA 2009-00101-00-00. F. Peregrina thanks the INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria) and European Social Fund for its post-doctoral grants and E. Pérez-Álvarez thanks the INIA for her pre-doctoral grant.Peer Reviewe

Geoquímica del W en el área circundante al yacimiento de cheelita de Barruecopardo (Salamanca)

La microclinización, proceso ácido débil, implica una corrosión de plagioclasas y una transformación biotita-clorita, con paso del W de dicha biotita a la fase volátil, bajo forma compleja. El descenso de presión en las fisuras (filones) hace precipitar a los wolframatos. Este mecanismo explica el empobrecimiento en W en las inmediaciones del yacimiento, y justifica una explicación geoquímica y mineralógica expuesta precedentemente