Some aspects of N=2 superstring

The string model with N=2 world-sheet supersymmetry is approached via ghosts, Becchi-Rouet-Stora-Tyutin cohomology, and bosonization. Some amplitudes involving massless scalars and vectors are computed at the tree level. The constraints of locality on the spectrum are analyzed. An attempt is made to "decompactify" the model into a four-dimensional theory.

Three-dimensional aspects of fluid flows in channels. II. Effects of meniscus and thin film regimes on viscous fingers

We perform a three-dimensional study of steady state viscous fingers that develop in linear channels. By means of a three-dimensional lattice-Boltzmann scheme that mimics the full macroscopic equations of motion of the fluid momentum and order parameter, we study the effect of the thickness of the channel in two cases. First, for total displacement of the fluids in the channel thickness direction, we find that the steady state finger is effectively two-dimensional and that previous two-dimensional results can be recovered by taking into account the effect of a curved meniscus across the channel thickness as a contribution to surface stresses. Second, when a thin film develops in the channel thickness direction, the finger narrows with increasing channel aspect ratio in agreement with experimental results. The effect of the thin film renders the problem three-dimensional and results deviate from the two-dimensional prediction.

Three-dimensional aspects of fluid flows in channels. I. Meniscus and thin film regimes

We study the forced displacement of a fluid-fluid interface in a three-dimensional channel formed by two parallel solid plates. Using a lattice-Boltzmann method, we study situations in which a slip velocity arises from diffusion effects near the contact line. The difference between the slip and channel velocities determines whether the interface advances as a meniscus or a thin film of fluid is left adhered to the plates. We find that this effect is controlled by the capillary and Péclet numbers. We estimate the crossover from a meniscus to a thin film and find good agreement with numerical results. The penetration regime is examined in the steady state. We find that the occupation fraction of the advancing finger relative to the channel thickness is controlled by the capillary number and the viscosity contrast between the fluids. For high viscosity contrast, lattice-Boltzmann results agree with previous results. For zero viscosity contrast, we observe remarkably narrow fingers. The shape of the finger is found to be universal.

Three-dimensional aspects of fluid flows in channels. II. Effects of meniscus and thin film regimes on viscous fingers

We perform a three-dimensional study of steady state viscous fingers that develop in linear channels. By means of a three-dimensional lattice-Boltzmann scheme that mimics the full macroscopic equations of motion of the fluid momentum and order parameter, we study the effect of the thickness of the channel in two cases. First, for total displacement of the fluids in the channel thickness direction, we find that the steady state finger is effectively two-dimensional and that previous two-dimensional results can be recovered by taking into account the effect of a curved meniscus across the channel thickness as a contribution to surface stresses. Second, when a thin film develops in the channel thickness direction, the finger narrows with increasing channel aspect ratio in agreement with experimental results. The effect of the thin film renders the problem three-dimensional and results deviate from the two-dimensional prediction.

Three-dimensional aspects of fluid flows in channels. I. Meniscus and thin film regimes

We study the forced displacement of a fluid-fluid interface in a three-dimensional channel formed by two parallel solid plates. Using a lattice-Boltzmann method, we study situations in which a slip velocity arises from diffusion effects near the contact line. The difference between the slip and channel velocities determines whether the interface advances as a meniscus or a thin film of fluid is left adhered to the plates. We find that this effect is controlled by the capillary and Péclet numbers. We estimate the crossover from a meniscus to a thin film and find good agreement with numerical results. The penetration regime is examined in the steady state. We find that the occupation fraction of the advancing finger relative to the channel thickness is controlled by the capillary number and the viscosity contrast between the fluids. For high viscosity contrast, lattice-Boltzmann results agree with previous results. For zero viscosity contrast, we observe remarkably narrow fingers. The shape of the finger is found to be universal.

Science in Western Islam. The circulation of knowledge in Mediterranean region

La Mediterrània ha estat gresol de la circulació d¿idees i persones des de fa mil·lennis. Durant l¿edat mitjana, però, el moviment més rellevant va ser, tal vegada, el que es va produirentre l¿Orient (Maixriq) i l¿Occident (Magrib) islàmics. Els viatges d¿estudis, íntimament units a les prescripcions religioses,varen convertir els científics musulmans en membres especialment actius en la difusió dels coneixements i dels avenços ques¿anaven adquirint a la capital de l¿imperi, Bagdad. Lluny de ser mers «transportistes» de la ciència, el nivell cultural assolit durantl'edat d'or abbassí els va convertir en un dels clímaxs intel·lectuals de la història. Al principi, tot i restar en un discret segonpla, els científics del nord d¿Àfrica i, especialment, els científicsd'al-Andalus varen tenir un paper essencial en la transmissióde la ciència oriental cap a una Europa que en va recollir el testimoni.Per això l¿aportació de la cultura araboislàmica és un esglaó sense el qual és impossible entendre la ciència posterior.Els camps conreats foren diversos: medicina, agronomia,òptica... però l¿àmbit que presidí la ciència fou, sens dubte,l¿astronomia (relacionada, al seu torn, amb les matemàtiques i la geografia). Els noms dels astrònoms més rellevants (desd¿al-Khwarizmi fins a Azarquiel) i les fites que varen assolir justifiquen que fossin coneguts per un públic ampli. Malgrat tot, continuen essent uns grans desconeguts.

The pivot player in handball and patterns detection - instrument

The theoretical context of this study is related with the observational methodology in the context of group games and sports studies, specifically Handball. Thus, this study intends to analyze the performance of the pivot player in the World Cup 2007 - Germany, European 2008 - Norway 2008 and China OG 2008 in a qualitative dimension. Our purpose was to get as much information as possible about the whole activity of the pivot player, by identifying sequential patterns of behaviour or conduct of the player/game, by using the sequential analysis. The observation instrument used to meet the main purpose of this work consists of a combination of format fields (FF) and systems of categories (SC). The codifications undertaken occurred in several handball games. Using this instrument we have shown that it provides support for the purposes for which it was developed, allowing more research into the offensive process of handball. Besides this, it makes possible the analysis of aspects of the game through perspective and contextual sequences, which we consider to be more accurate, to fit the "reality" of a game such as handball.

Mesura de la força i de la potència en l'esport. Aplicació del chronojump boscosystem

El propòsit del Treball de Fi de Grau és dissenyar un document que serveixi als usuaris del Chronojump Boscosystem per aprendre a utilitzar-lo i treure’n el màxim rendiment. Previ a l’elaboració d’aquest, s’ha requerit un treball de documentació teòrica, fet a través de la revisió bibliogràfica i entrevistes a experts en preparació física dintre del món de l’entrenament esportiu, procés que ha servit per a establir les bases i els fonaments del dossier didàctic. Aquest últim està compost per deu pràctiques on, en cadascuna d’elles, es treballen aspectes concrets del programa Chronojump. Cada una d’aquestes consta d’una primera part més teòrica on es defineixen els aspectes a tractar, seguit de la seqüència de passos a fer per a portar a terme la pràctica i, finalment, deu preguntes tipus test per a saber si s’ha comprès la informació donada i el funcionament del programa. En les pràctiques on s’ha de passar algun test, s’afegeix també un suport audiovisual per tal de deixar clar l’execució i la tècnica correcta de la prova en qüestió.

Food Indicators and Their Relationship with 10 to 12 Year-olds' Subjective Well-Being

This study aimed to test subjective indicators designed to analyze the role food plays in children’s lives, explore children’s personal well-being, and evaluate the relationship between these two phenomena. It was conducted on 371 children aged 10 to 12 by means of a selfadministered questionnaire. Results showed a marked interest in food on the part of children, who consider taste and health the most important indicators when it comes to eating. They demonstrated a high level of personal well-being, measured using Cummins & Lau’s adapted version of the Personal Well- Being Index–School Children (PWI-SC) (2005), overall life satisfaction (OLS) and satisfaction with various life domains (friends, family, sports, food and body). Regression models were conducted to explain satisfaction with food, taking as independent variables the interest children have in food, the importance they give to different reasons for eating, scores from the PWI-SC, OLS and satisfaction with various life domains. In the final model, it was found that OLS, health indicators, satisfaction with health from the PWI-SC and satisfaction with your body contribute to explaining satisfaction with food. The results obtained suggest that satisfaction with food is a relevant indicator in the exploration of children’s subjective well-being, calling into question the widespread belief that these aspects are of exclusive interest to adults. They also seem to reinforce the importance of including food indicators in any study aimed at exploring the well-being of the 10 to 12 year-old population.

Islam i immigració: el cas de les dones musulmanes delbarri de Rocafonda a Mataró

La presència actual de l’Islam a Catalunya és una realitat innegable, així com ho ésl’existència de població estrangera musulmana, que fa del nostre país un territori cadavegada més multicultural. De fet, en els últims anys, l’establiment definitiu de famíliesmusulmanes, que ha substituït a l’arribada intermitent preferentment masculina per atreballar, ha donat lloc a uns canvis en la societat catalana. Uns canvis queprincipalment són causats per l’augment de la visibilitat d’una comunitat que esdistingeix per seguir una religió diferent a la professada tradicionalment a Espanya i aCatalunya. Malgrat el passat islàmic a la Península Ibérica, l’Islam és una religió que esconcep en termes d’alteritat, desconeguda per a molts i sobretot, identificada moltesvegades de manera negativa i estereotipada.

Islam político en Europa: un análisis actual de las teorías de S. P. Huntington : El paradigma español

Análisis actual sobre las teorías de S. P. Huntington aplicadas al contexto de la Unión Europea, respecto al islam político. Comparativa del islam primitivo con otros sistemas totalitarios y argumentación para la convivencia del islam actual en las sociedades modernas del marco europeo.