3D LES simulations of a static and vertically free-to-oscillate 4:1 rectangular cylinder: Effects of the grid resolution

Vortex induced vibration (VIV) is an important phenomenon which appears in flexible structures immersed in a moving fluid. This oscillation is self-sustained and self-limited, but VIV might cause fatigue damage and affect the structure's serviceability.In the present study, the aerodynamics of the flow fields around a static and vertically free-to-oscillate 4:1 rectangular cylinder are analysed by means of 3D LES simulations, adopting the OneEqEddy viscosity model. Integral parameters, pressure distributions, amplitudes of oscillation, coherences and correlations are obtained and compared with the available experimental data. Aiming to ascertain the impact of the boundary conditions and the grid resolution on the accuracy of results, five cases adopting 3 different meshes including two different spanwise discretisations have been considered. When studying the aerodynamics of the cylinder in static conditions, the influence of the spatial discretisation is very limited, and the agreement with experimental data is fairly good. On the other hand, for the free-to-oscillate cylinder, the structural response is dramatically dependent on the spanwise discretisation. The maximum amplitude of the structural response decreases as the mesh resolution increases, providing a closer fit with the experimental data. Also, the spanwise correlation of pressures is studied, finding remarkable differences depending on the level of spatial discretisation

Strain balanced quantum posts

Quantum posts are assembled by epitaxial growth of closely spaced quantum dot layers, modulating the composition of a semiconductor alloy, typically InGaAs. In contrast with most self-assembled nanostructures, the height of quantum posts can be controlled with nanometer precision, up to a maximum value limited by the accumulated stress due to the lattice mismatch. Here we present a strain compensation technique based on the controlled incorporation of phosphorous, which substantially increases the maximum attainable quantum post height. The luminescence from the resulting nanostructures presents giant linear polarization anisotropy.Comment: Submitted to Applied Physics Letters (7th March 2011). 4 pages, 4 figure

Integración flexible de workflows científicos en entornos de computación dinámicos

La aparición de potentes infraestructuras de computación Grid ha impulsado un creciente interés por parte de la comunidad científica para automatizar la ejecución de sus experimentos. Para ello, la utilización de workflows científicos resulta clave de cara a aprovechar las oportunidades que presentan este tipo de infraestructuras, debido principalmente a las características que presentan: están formados por un elevado número de tareas con un alto coste computacional, que manejan grandes volúmenes de datos complejos y que requieren una gestión adecuada de los recursos tanto software como hardware disponibles. Sin embargo, la complejidad de los propios workflows y de las infraestructuras de computación provoca que el proceso de scheduling resulte complejo y difícil. Las propuestas actuales utilizan un broker de recursos que facilita esta tarea pero provoca que el diseño del workflow esté fuertemente acoplado con el middleware que gestiona la infraestructura. Esto imposibilita la utilización conjunta de diferentes Grids, la compartición y portabilidad de los workflows y la gestión flexible del ciclo de vida de los mismos. Para solucionar estas limitaciones, se plantea una infraestructura flexible a la hora de integrar workflows de diferentes lenguajes, diversas infraestructuras de computación (Grid, Cloud, etc.) y componentes de gestión que permitan enriquecer y mejorar la ejecución de los workflows. La utilización de redes de Petri de alto nivel se plantea como base, dada la amplia experiencia en este campo por parte del Grupo de Integración de Sistemas Distribuidos y Heterogéneos (GIDHE), grupo en el que se enmarca la línea de investigación del autor. Esta propuesta introduce nuevos retos en la decisión de las infraestructuras en las que ejecutar los workflows (meta-scheduling), siendo la simulación una alternativa muy adecuada al ser capaz de prever el comportamiento del workflow en diferentes escenarios

OptEEmAL: Decision-Support Tool for the Design of Energy Retrofitting Projects at District Level

Designing energy retrofitting actions poses an elevated number of problems, as the definition of the baseline, selection of indicators to measure performance, modelling, setting objectives, etc. This is time-consuming and it can result in a number of inaccuracies, leading to inadequate decisions. While these problems are present at building level, they are multiplied at district level, where there are complex interactions to analyse, simulate and improve. OptEEmAL proposes a solution as a decision-support tool for the design of energy retrofitting projects at district level. Based on specific input data (IFC(s), CityGML, etc.), the platform will automatically simulate the baseline scenario and launch an optimisation process where a series of Energy Conservation Measures (ECMs) will be applied to this scenario. Its performance will be evaluated through a holistic set of indicators to obtain the best combination of ECMs that complies with user's objectives. A great reduction in time and higher accuracy in the models are experienced, since they are automatically created and checked. A subjective problem is transformed into a mathematical problem; it simplifies it and ensures a more robust decision-making. This paper will present a case where the platform has been tested.This research work has been partially funded by the European Commission though the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 680676. All related information to the project is available at https://www.opteemal-project.eu

Osteoblastoma del sacro. A propósito de dos casos clínicos.

El osteoblastoma es un tumor óseo primitivo de frecuente localización en los elementos posteriores de la columna vertebral, aunque raro en el sacro. Se presentan dos osteoblastomas del sacro, con un seguimiento medio de ocho años, tratados mediante resección intralesional que, sin morbilidad, deparó un excelente resultado. El curetaje sería un procedimiento de resección válido en osteoblastomas sacros no agresivos, si bien obliga a un seguimiento prolongado del paciente para vigilar la posibilidad de recidivas locales.Osteoblastoma is a primary neoplasm of bone fre- quently located in the posterior elements of the spine, alt- hough rarely affecting the sacrum. Two cases in this location are reported, with a mean follow-up of eight years, treated with an intralesional resection that, without any morbidity, has provided an excellent result. Curettage should be a valid re- section procedure for nonagressive osteoblastomas of the sacrum, although it makes necessary a long follow-up in or- der to watch over the possibility of a local recurrence

Recent Overview of Solar Photocatalysis and Solar Photo-Fenton Processes for Wastewater Treatment

This literature research, although not exhaustive, gives perspective to solar-driven photocatalysis, such as solar photo-Fenton and TiO2 solar photocatalysis, reported in the literature for the degradation of aqueous organic pollutants. Parameters that influence the degradation and mineralization of organics like catalyst preparation, type and load of catalyst, catalyst phase, pH, applied potential, and type of organic pollutant are addressed. Such parameters may also affect the photoactivity of the catalysts used in the studied solar processes. Solar irradiation is a renewable, abundant, and pollution-free energy source for low-cost commercial applications. Therefore, these solar processes represent an environmentally friendly alternative mainly because the use of electricity can be decreased/avoided

Encapsulation of Lactobacillus fermentum K73 by Refractance Window drying

The purpose of this work was to model the survival of the microorganism and the kinetics of drying during the encapsulation of Lactobacillus fermentum K73 by Refractance Window drying. A whey culture medium with and without addition of maltodextrin were used as encapsulation matrices. The microorganism with the encapsulation matrices was dried at three water temperatures (333, 343 and 353 K) until reaching balanced moisture. Microorganism survival and thin layer drying kinetics were studied by using mathematical models. Results showed that modified Gompertz model and Midilli model described the survival of the microorganism and the drying kinetics, respectively. The most favorable process conditions found with the mathematical modelling were a drying time of 2460 s, at a temperature of 353 K. At these conditions, a product with 9.1 Log CFU/g and a final humidity of 10% [wet basis] using the culture medium as encapsulation matrix was obtained. The result shows that Refractance Window can be applied to encapsulate the microorganism probiotic with a proper survival of the microorganism

Forecasting confined spatiotemporal chaos with genetic algorithms

A technique to forecast spatiotemporal time series is presented. it uses a Proper Ortogonal or Karhunen-Lo\`{e}ve Decomposition to encode large spatiotemporal data sets in a few time-series, and Genetic Algorithms to efficiently extract dynamical rules from the data. The method works very well for confined systems displaying spatiotemporal chaos, as exemplified here by forecasting the evolution of the onedimensional complex Ginzburg-Landau equation in a finite domain.Comment: 4 pages, 5 figure

Learning styles and their relationship with the Technologies of Information and Communication (TIC) in the adaptation of pharmacy studies to the ESHE

Introducción: El conocimiento de los estilos de aprendizaje es fundamental para el docente a fin de comprender cómo aprenden sus alumnos y así modificar/reforzar su estilo de enseñanza. La aplicación de las nuevas Tecnologías de la Comunicación y de la Información (TIC) facilita la adaptación de las enseñanzas universitarias al Espacio Europeo de Educación Superior (EEES). Objetivo: Evaluar el estilo de aprendizaje de los alumnos de Farmacia de la Universidad Complutense de Madrid (UCM) y comparar dichos estilos con las TIC. Metodología: Alumnos de 4º curso de licenciatura en Farmacia y de postgrado. Todos respondieron al cuestionario CHAEA de estilos de aprendizaje. Además, se ha planteado un nuevo cuestionario para correlacionar estilos de aprendizaje y TIC. Discusión: Las puntuaciones positivas más elevadas correspondieron al estilo reflexivo seguido del teórico. Más del 80% de los alumnos muestran preferencia muy elevada por las clases magistrales (puntuaciones 4-5, siendo 5 la puntación de máxima preferencia). Este resultado estaría en concordancia con el estilo mayoritario de aprendizaje de los alumnos evaluados. Más del 90% de los alumnos valora de forma altamente positiva (4-5) la impartición de clases mediante la utilización de presentaciones en PowerPoint y, a continuación la utilización de la pizarra y la proyección de videos. Conclusiones: El estilo de aprendizaje de los alumnos de cuarto curso de Farmacia y de postgrado es fundamentalmente reflexivo aunque valoran de forma altamente positiva la utilización de las TIC, lo que confirma la importancia de su uso en la consecución de los objetivos del EEES.Introduction: knowledge of the learning styles of Pharmacy students is an important tool that can be used to improve teaching thereby reinforcing the use of appropriate and transferable teaching strategies. For this, the use of the Technologies of Information and Communication (TIC) may facilitate the implementation of the European Space for Higher Education (ESHE). Objective: To evaluate the learning styles of graduate and postgraduate pharmacy students at the Universidad Complutense of Madrid and, to compare the student´s learning styles with their preferences regarding the use of the TIC. Methods: The study was performed on fourth-year pharmacy students and postgraduate students. The instrument used to analyze the learning styles was the CHAEA questionnaire. Moreover, a new questionnaire was developed and implemented in order to establish a correlation between learning styles and TIC. Results: The preferred learning styles corresponded to reflexive and, in second place, theoretical learning. More than 80% of the students highly graded traditional lectures (4-5, being 5 the grade for maximum preference), with this result in accordance with the main learning style of the population assayed. More than 90% of the students also positively graded (4-5) multimedia presentations using PowerPoint software, followed by the use of blackboard and videos. Conclusions: The main learning style of fourth-year graduate students and postgraduate students at the School of Pharmacy (UCM) is reflexive. The populations assayed highly and positively graded the use of TIC, thereby stating their importance in the implementation of the ESHE