Importancia del colegio para la prevención del sobrepeso y la obesidad en minorías étnicas

En el presente Trabajo de Fin de Grado se trata la problemática del sobrepeso y la obesidad centrándose sobre todo en los niños y más concretamente la etnia gitana, por un docente especialista en Educación Física. Además se ha llevado a cabo una investigación en el C.E.I.P Cristóbal Colón de Valladolid. Dicha investigación se centra en averiguar la alimentación de los niños de ocho a trece años gitanos del colegio y algunos de sus hábitos alimenticios, además de compararlo con la población marroquí y contrastar la información con los padres. Estas enfermedades cada vez son más comunes en nuestra sociedad y no son nada buenas por los problemas de salud que acarrean, por ello hay que actuar.Grado en Educación Primari

Shock wave study and theoretical modeling of the thermal decomposition of c-C4F8

The thermal dissociation of octafluorocyclobutane, c-C4F8, was studied in shock waves over the range 1150-2300 K by recording UV absorption signals of CF2. It was found that the primary reaction nearly exclusively produces 2 C2F4 which afterwards decomposes to 4 CF2. A primary reaction leading to CF2 + C3F6 is not detected (an upper limit to the yield of the latter channel was found to be about 10 percent). The temperature range of earlier single pulse shock wave experiments was extended. The reaction was shown to be close to its high pressure limit. Combining high and low temperature results leads to a rate constant for the primary dissociation of k1 = 1015.97 exp(-310.5 kJ mol-1/RT) s-1 in the range 630-1330 K, over which k1 varies over nearly 14 orders of magnitude. Calculations of the energetics of the reaction pathway and the rate constants support the conclusions from the experiments. Also they shed light on the role of the 1,4-biradical CF2CF2CF2CF2 as an intermediate of the reaction.Fil: Cobos, Carlos Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Hintzer, K.. Dyneon Gmbh; AlemaniaFil: Sölter, L.. Universität Göttingen; AlemaniaFil: Tellbach, E.. Universität Göttingen; AlemaniaFil: Thaler, A.. Dyneon Gmbh; AlemaniaFil: Troe, J.. Universität Göttingen; Alemania. Max-Planck-Institut fu¨r biophysikalische Chemie; Alemani

Theoretical determination of the rate constant of the CCl2 + CCl2 → C2Cl4 association reaction

En un estudio previo se determinó la constante de velocidad de la reacción CCl2+CCl2 → C2Cl4 empleando la técnica de fluorescencia inducida por láser. En el presente trabajo determinamos mediante el modelo de los canales estadísticamente adiabáticos la constante de velocidad de este proceso en el régimen de alta presión. Se empleó la teoría del funcional de la densidad para determinar las propiedades moleculares de los reactivos y del complejo activado. Entre 300 K y 2000 K se obtuvo la siguiente expresión k∞ = (1,5 ± 0,4) x 10-12 x (T / 300K) (0.50±0.07) exp[-(260 ± 10) K/T] cm3 molécula-1 s-1. El valor a temperatura ambiente está en muy buen acuerdo con el valor experimental determinado en nuestro laboratorio.In a previous work we used the laser induced fluorescence technique to determine the rate constant of the CCl2 + CCl2 association reaction. In the present work we determined by the statistical adiabatic channel model the temperature dependence of the rate constant in the high pressure regime. The density functional theory was used to characterize the properties of the parent molecules and the activated complex. Within 300 K and 2000 K we obtained the following expression k∞ = (1,5 ± 0,4) x 10-12 x (T / 300K)(0.50±0.07) exp[- (260 ± 10) K/T] cm3 molécula-1 s-1. The value at room temperature is in very good agreement with the experimental value obtained in our laboratory.Fil: Gómez, Nicolás Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Azcárate, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Codnia, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Cobos, Carlos Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

El Opac social Infobook de BBVA: un estudio de caso

A case study is presented, Infobook, a library 2.0 social OPAC, designed within a knowledge management global proyect for the Innovation & Knowledge Management Information Centre at BBVA international bank. The design and development process is described. The software selected was Koha, integrated library system distributed under GPL license, having as a primary objective to give authomatized support to the Information Centre´s tasks, but also offering functionalities and services that needed to go ahead from the limits of the classical ILS. On Infobook, the Social Opac is not only a retrieval information system for the catalog of the library, but boldly goes beyond, having an innovative point of view: user participation to support the evolution of the knowledge management corporative library. This participation involves not only collaboration and development of 2.0 tools, but also the possibility for the patrons to upload and catalogue documents by themselves

Chiral Symmetry transition in the Linear Sigma Model with quarks: Counting effective QCD degrees of freedom from low to high temperature

We use the linear sigma model coupled to quarks, together with a plausible location of the critical end point (CEP), to study the chiral symmetry transition in the QCD phase diagram. We compute the effective potential at finite temperature and density up to the contribution of the ring diagrams, both in the low and high temperature limits, and use it to compute the pressure and the position of the CEP. In the high temperature regime, by comparing to results from extrapolated lattice data, we determine the model coupling constants. Demanding that the CEP remains in the same location when described in the high temperature limit, we determine again the couplings and the pressure for the low temperature regime. We show that this procedure gives an average description of the lattice QCD results for the pressure and that the change from the low to the high temperature domains in this quantity can be attributed to the change in the coupling constants which in turn we link to the change in the effective degrees of freedom.Comment: Title changed, accepted for publication in International Journal of Modern Physics

Design and analysis of ripple-based controls based on the discrete modeling and Floquet theory

Ripple-based controls can strongly reduce the required output capacitance in PowerSoC converter thanks to a very fast dynamic response. Unfortunately, these controls are prone to sub-harmonic oscillations and several parameters affect the stability of these systems. This paper derives and validates a simulation-based modeling and stability analysis of a closed-loop V 2Ic control applied to a 5 MHz Buck converter using discrete modeling and Floquet theory to predict stability. This allows the derivation of sensitivity analysis to design robust systems. The work is extended to different V 2 architectures using the same methodology

Overview, equivalences and design guidelines of v1 concept: A voltage mode control that behaves as a current-mode with near time-optimal response

This paper summarizes the proposed v1 concept, that explains how by only measuring the output voltage, designers have information about almost every signal of the power stage. Following the v1 concept, the implementation of some ripple-based controls as a conventional voltage mode control or current mode control is studied. Based on these, it is explained how to design a traditional type-III voltage mode control to behave like a current mode control with near time-optimal response under load transients. The work is validated in simulations and experimentally on a 300kHz Buck converter

Impact of the control on the size of the output capacitor in the integration of Buck converters

One of the main challenges in PowerSoC converters is the integration of the output capacitor. In some applications, the minimum value of the capacitance is constrained not by the maximum allowed voltage ripple but by dynamic requirements. This paper investigates for a 10 MHz Buck converter if the design of very fast controls can reduce the required output capacitor and which controls are more suitable. It is also analyzed the effect that the moment in which the load transient can occur has on the reduction of the size of the output capacitor

Clinical skills training in the third course of Medicine. Sequential evaluation of five cycles

Introducción: Existen pocos estudios que de forma selectiva valoren la docencia clínica de una determinada asignatura. En este artículo se presenta la experiencia en docencia clínica de la asignatura 'Semiología General y Propedéutica Clínica' en tercer curso del Grado de Medicina en la Facultad de Medicina de la Universitat de Barcelona. Materiales y métodos: Se han analizado los cursos 2011-2012, 2012-2013 y 2013-2014, representando un total de cinco 'cursos', ya que la asignatura es semestral y se imparte dos veces en cada curso académico. El período de docencia clínica de la asignatura es de siete semanas (28 días) y el número de alumnos oscila entre cuatro y ocho por cada una de las siete unidades/centros distintos. A su llegada se les informa de los objetivos de la estancia clínica y al final del período se les invita a cumplimentar una encuesta anónima y voluntaria en la que valoran distintos ítems. Resultados: Se han recogido 477 encuestas (95%). Se constató una muy buena valoración global del período de docencia clínica (mediana: 5; primer cuartil: 4, en escala de 1 a 5), sin variaciones significativas entre los distintos períodos evaluados (p = 0,658). Conclusiones: La docencia clínica en esta asignatura está muy bien valorada de forma global, sin detectar variaciones relevantes en los cinco cursos analizados

Analysis of the effect of modulation delays on the size of the output capacitor

Constant frequency (PWM), constant on-time (COT) and constant off-time modulations exhibit inherent delays where the controller is unable to respond instantaneously. These delays can increase the required size of the output capacitor to meet dynamic requirements in applications with high demanding load such as the supply of microprocessors. This paper analyzes the minimum required output filter (output inductor and output capacitor) to meet a given specification and quantifies the effect that different modulations have in the minimum size of the output capacitor. The paper also shows a novel technique to mitigate the delays of the modulations by means of synchronizing the load step with the clock of the modulation. This technique is applicable to most of controllers as it only acts on the modulator