Estudio numérico de la generación de vórtices de punta de álabe en una placa plana

Los vórtices de punta de ala que se generan en las superficies sustentadoras son los causantes de la resistencia inducida, la cual es una parte importante de la resistencia aerodinámica de estas superficies. No obstante, este fenómeno no es únicamente perjudicial, es posible aprovechar el carácter rotatorio y mezclador de este tipo de flujo. Concretamente, estos torbellinos pueden utilizarse en dispositivos mezcladores para optimizar dichos dispositivos. Este documento trata de analizar, haciendo uso de simulaciones numéricas, cuál es la configuración óptima de una placa plana con el fin de obtener la mayor eficiencia en los vórtices generados. Es decir, la mayor intensidad con la menor resistencia aerodinámica generada. Los parámetros que se estudian en cuanto a la configuración de la placa son el ángulo de ataque y su forma en planta. Aunque el objetivo fundamental de este estudio es determinar el punto óptimo, también se analiza el comportamiento de estos vórtices. Por esta razón se estudian las tendencias que siguen la intensidad de los torbellinos, la resistencia y la eficiencia con los parámetros contemplados.The wingtip vortices generated in wing surfaces are the cause of induced resistance which is an important part of the aerodynamic resistance of these surfaces. However, this phenomenon is not only harmful, but also it is possible to use the rotary and mixer nature of this kind of flow. Specifically, these vortices can be used in mixing devices to optimize the mixer efficiency. This document attempts to analyze, using numerical simulations, the optimal configuration of a flat plate in order to obtain greater efficiency in the vortices generated. In other words, the highest intensity with the least generated aerodynamic resistance. The parameters studied in terms of the configuration of the plate are the angle of attack and its planform. Although the main objective of this study is to determine the optimum point, the behavior of these vortices is also analyzed. For this reason the trends that follow the intensity of the vortices, resistance and efficiency with the examined parameters are studied.Universidad de Sevilla. Grado en Ingeniería Aeroespacia

La categoría de Lusternik-Schnirelmann de los espacios finitos. Enunciado y discusión de un problema

El trabajo presenta el invariante homotópico conocido como categoría de Lusternik-Schnirelmann (categoría LS, para simplificar) para espacios finitos. La topología y homotopía de estos espacios se resumen en un capítulo inicial y se continúa con los elementos de la categoría LS clásica. El capítulo final está abierto, ya que plantea problemas sobre la categoría LS de espacios finitos de los que desconocemos la solución. Una serie de ejemplos, comentarios y resultados conocidos sirven para presentar los problemas.This work focuses on the homotopical invariant termed Lusternik-Schnirelmann category (LS category, for short) of finite spaces. A brief account of the topology and homotopy of this class of spaces is followed by an introduction of the basics of classical LS category. The last chapter contains several open questions together with a series of related examples, observations and known results.Universidad de Sevilla. Grado en Matemática

Remodelado de los conos de Dirac en aislantes topológicos y grafeno

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Física de Materiales, leída el 04-10-2019Quantum mechanics was in all its splendour at the beginning of the twentieth century with the great minds of Schrödinger, Heisenberg, Dirac, Pauli and many others. The concepts introduced by then were truly revolutionary, even more than Einstein’s relativity, one would dare say. One may have a feeling that nowadays we only exploit the consequences of quantum mechanics to build devices such as transistors or light-emitting diodes, which on the other hand have changed the world we live in beyond imagination. With regard to the theoretical front, it may seem that one only has to turn the mathematical handle to work out consequences of quantum mechanics, although no new concepts are in sight. However, nothing could be farther from the truth. We are priviledged to live in what has been dubbed as a second quantum revolution...La mecánica cuántica alcanzó su máximo esplendor a principios del siglo XX de la mano de grandes científicos como Schrödinger, Heisenberg, Dirac, Pauli y muchos otros. Los conceptos que estos físicos introdujeron fueron increíblemente revolucionarios, incluso uno podría aventurar a decir que superaron a la relatividad de Einstein. Hoy en día pudiera parecer que únicamente explotamos las consecuencias de la mecánica cuántica para construir transistores o diodos emisores de luz, dispositivos que, por otra parte, han cambiado por completo el mundo en el que vivimos. En lo que respecta a la física teórica, uno podría pensar que lo único que queda por hacer es encender la maquinaria matemática y esperar a obtener resultados, sin nuevos conceptos que descubrir. Sin embargo, nada más lejos de la realidad. Tenemos la suerte de vivir en lo que los expertos denominan la segunda revolución cuántica...Fac. de Ciencias FísicasTRUEunpu

Methods for Characterizing Multiphase Magnetocaloric Materials

This thesis is aimed to study the characteristics of thermomagnetic phase transitions and the resulting magnetocaloric effect in multiphase magnetocaloric materials, which is a very common scenario in the research of the magnetocaloric effect and can lead to complex situations that need to be properly approached. On the one hand, composites that combine various phases with Curie transitions close to each other are interesting and highly studied as they can lead to an enhanced refrigerant capacity with respect to the pure phases while keeping a large enough response. In this thesis, newly developed Gd + Gd7Pd3 composites are presented as a case in which the mentioned improvement of the refrigerant capacity is achieved. This intentional situation of overlapping Curie transitions has been used for the development of a method for the deconvolution of the magnetocaloric responses by means of the scaling laws of the magnetocaloric effect. On the other hand, materials exhibiting magnetostructural transformation (first-order phase transition) can also show the Curie transitions of the phases (second-order phase transition), where the phase transitions of different type can be concurrent. This situation is approached using Heusler alloys undergoing magnetostructural transformation located close to the Curie transitions of the martensitic and austenitic phases. The competing effect of both types of phase transitions in this case is investigated by experimental and analytical methods. The deconvolution method used for the composites is successfully applied here, enabling the subtraction of the Curie transition to the total response. It has to be noted that these situations of overlapping phase transitions can also occur unintentionally (i.e., due to the presence of impurities during synthesis). Therefore, the developed methods can also be used in these situations to know the effect of additional phase transitions and to gauge the actual response of the desired phase. Additionally, it has also been shown how the overlapping Curie transitions of the phases affect the hysteretic signature of the alloys undergoing magnetostructural transformation. This study is addressed through the emerging Temperature first-order reversal curves (TFORC) method for the study of magnetocaloric materials, using again Heusler alloys as a model case. This part combines experimental results with results from the modelling of the thermomagnetic behavior of the material. This has enabled a direct correlation between the characteristics of the thermomagnetic behavior of the alloys and the features of the TFORC distributions. Finally, the emerging topic of using polymer-based composites for the 3D printing of functional parts is addressed. Here, the main existing problem lies in the fabrication of uniform composite materials that allow the 3D printing of parts with predictable and repeatable functionality without relying on industrial techniques. A novel manufacturing method of polymer-based filaments containing functional fillers is proposed. Soft-magnetic steel particles have been used to manufacture polymer-based magnetic composites as proof of concept of the validity of the method. Once validated, the method is used to manufacture polymer-based magnetocaloric composites for additive manufacturing. The relatively simple method provides highly homogeneous filaments that preserve the magnetic functionality of the fillers. However, the property of the polymeric matrix is significantly affected by the addition of the metallic fillers, which has an important influence on the processability parameters both for the extrusion and printing

Design, creation and implementation of characters for video games Final Degree Work report

Treball final de Grau en Disseny i Desenvolupament de Videojocs. Codi: VJ1241. Curs acadèmic: 2018/2019This document has been created in order to explain the process of character modeling for video games and its implementation in a game engine. Its main objective is that the reader can understand, without going into technical details, the general process followed to develop a character of these characteristics. It is interesting because many people do not know the effort and work it takes to make the video games they consume

Reducing Self-Stigma in People with Severe Mental Illness Participating in a Regular Football League: An Exploratory Study

For the past 15 years, a regular indoor football competition has been taking place in Madrid (Spain) with 15 teams from different mental health services in the city, in which teams face off weekly as part of a competition lasting nine months of the year. We are not aware of whether a similar competition experience is offered in other cities. The purpose of the present study was to evaluate whether participating in this league, called Ligasame, has an influence on participants’ self-stigma. To do so, the Internalized Stigma of Mental Illness scale (ISMI) was adapted into Spanish and applied to 108 mental health patients, 40% of which participated in Ligasame, and the remainder of which did not. The results obtained reflect significant differences between those participating in Ligasame and those that did not in terms of two specific dimensions related to self-stigma (stereotype endorsement and stigma resistance) and total score. On the other hand, no significant differences were found in terms of other variables, such as patients’ prior diagnosis, age or belonging to different resources/associations. In this article, we discuss the importance of these results in relation to reducing self-stigma through participation in a regular yearly mental health football league

Hacia una perspectiva constructivista en el análisis del tiempo libre como ocio deportivo

Buena parte de los análisis sociológicos contemporáneos sobre el ocio, el tiempo libre y deporte siguen alimentando la clásica dicotomía que distingue a la Sociedad del Individuo, aplicando así distintos sustantivos para designar a una misma e inseparable sustancia. La sociología aplicada más común suele inclinarse por describir a la estructura social en menoscabo del análisis individual-emocional del sujeto. En esta comunicación propongo, a partir de las aportaciones de Elias, Bourdieu y Foucault, una nueva mirada epistemológica para interpretar el deporte como modo histórico de ocupación del tiempo libre, disolviendo la polarización entre la perspectivas Sociedad-Individuo o sus variantes semánticas: micro-macro, estructura-agencia, materia-idea, objeto- sujeto, observado-observado