918 research outputs found

    Molecular Dynamics Simulations of Lead and Lithium in Liquid Phase

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    Pb17Li is today a reference breeder material in diverse fusion R&D programs worldwide. Extracting dynamic and structural properties of liquid LiPb mixtures via molecular dynamics simulations, represent a crucial step for multiscale modeling efforts in order to understand the suitability of this compound for future Nuclear Fusion technologies. At present a Li-Pb cross potential is not available in the literature. Here we present our first results on the validation of two semi-empirical potentials for Li and Pb in liquid phase. Our results represent the establishment of a solid base as a previous but crucial step to implement a LiPb cross potential. Structural and thermodynamical analyses confirm that the implemented potentials for Li and Pb are realistic to simulate both elements in the liquid phase

    New simulations to qualify eutectic lithium-lead as breeder material

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    Pb17Li is today a reference breeder material in diverse fusion R&D programs worldwide. One of the main issues is the problem of liquid metals breeder blanket behavior. The knowledge of eutectic properties like optimal composition, physical and thermodynamic behavior or diffusion coefficients of Tritium are extremely necessary for current designs. In particular, the knowledge of the function linking the tritium concentration dissolved in liquid materials with the tritium partial pressure at a liquid/gas interface in equilibrium, CT =f(PT ), is of basic importance because it directly impacts all functional properties of a blanket determining: tritium inventory, tritium permeation rate and tritium extraction efficiency. Nowadays, understanding the structure and behavior of this compound is a real goal in fusion engineering and materials science. Atomistic simulations of liquids can provide much information; not only supplementing experimental data, but providing new tests of theories and ideas, making specific predictions that require experimental tests, and ultimately helping to a deeper understandin

    Evolutionary stability and resistance to cheating in an indirect reciprocity model based on reputation

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    Indirect reciprocity is one of the main mechanisms to explain the emergence and sustainment of altruism in societies. The standard approach to indirect reciprocity is reputation models. These are games in which players base their decisions on their opponent's reputation gained in past interactions with other players (moral assessment). The combination of actions and moral assessment leads to a large diversity of strategies; thus determining the stability of any of them against invasions by all the others is a difficult task. We use a variant of a previously introduced reputation-based model that let us systematically analyze all these invasions and determine which ones are successful. Accordingly, we are able to identify the third-order strategies (those which, apart from the action, judge considering both the reputation of the donor and that of the recipient) that are evolutionarily stable. Our results reveal that if a strategy resists the invasion of any other one sharing its same moral assessment, it can resist the invasion of any other strategy. However, if actions are not always witnessed, cheaters (i.e., individuals with a probability of defecting regardless of the opponent's reputation) have a chance to defeat the stable strategies for some choices of the probabilities of cheating and of being witnessed. Remarkably, by analyzing this issue with adaptive dynamics we find that whether an honest population resists the invasion of cheaters is determined by a Hamilton-like rule, with the probability that the cheat is discovered playing the role of the relatedness parameter.This work has been supported by the Ministerio de Ciencia e Innovación (Spain) through grants MOSAICO and PRODIEVO, by the European Research Area Complexity-Net through grant RESINEE, and by Comunidad de Madrid (Spain) through grant MODELICO-CM. L.A.M.-V. was supported by a postdoctoral fellowship from Alianza 4 Universidades

    Microplastics in Aquatic Environments and Their Toxicological Implications for Fish

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    The intensive use of plastics and derivatives during the last century has increased the contamination of animal habitats. The breakdown of these primary plastics in the environment results in microplastics (MP), small fragments of plastic typically <1–5 mm in size. Apart from the potential negative effects of the MPs per se, it is generally assumed that microplastics may increase the exposure of marine aquatic organisms to chemicals associated with the plastics. In addition, to enhance the performance of plastics, additives are added during manufacture. Furthermore, they are active in absorbing other contaminants and be used as vectors of highly and well‐documented persistent contaminants. Finally, these small MPs are easily ingested by animals and affect their physiology and behaviour. Thus, aquatic living organisms are continuously exposed to these MPs, and associated contaminants, and could suffer from its contamination but also introduce them into the food chain

    Gestión online tienda de antigüedades Cambalache

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    El proyecto ha consistido en el desarrollo de una aplicación online y para la gestión de una tienda de antigüedades. Se podrá crear y mantener actualizado el catálogo de productos, las compras a proveedores y las ventas realizadas.Ingeniería Técnica en Informática de Gestió

    Aplicaciones a la investigación de mercados (Estadística y Market Research)

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    Actualmente, en el mercado empresarial existe una gran necesidad de obtener información de valor para la compañía. Las empresas precisan conocer la percepción de sus clientes para poder tomar medidas y mejorar sus servicios prestados. La competencia cada día es más fuerte y los clientes conocen mucho más las posibles alternativas de servicio o producto. La estadística es una herramienta que ofrece la oportunidad de obtener un análisis de la información necesaria para que una empresa conozca sus productos o servicios desde la perspectiva de su cliente para poder tomar decisiones estratégicas acertadas y mejorar su rentabilidad. Para nuestro caso práctico desarrollaremos el proyecto sobre el Servicio de Atención al Cliente (SAC)de una empresa del gas. Evaluaremos la satisfacción del cliente obteniendo datos a través de análisis descriptivos y un modelo de regresión lineal múltiple que nos identifique un ranking de atributos y a su vez nos sirva para las mejoras de la compañía.Grado en Estadístic

    Diseño e implementación de un jammer configurable en FPGA

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    [ES] Este trabajo fin de máster consiste en la realización de un prototipo de un sistema jammer. Estos sistemas tienen como función la transmisión de señales de radiofrecuencia para crear una interferencia intencionada con el objetivo de interrumpir o perturbar una comunicación por radiofrecuencia. Siendo el objetivo principal de este proyecto la interferencia de comunicaciones que empleen una modulación de salto en frecuencia, teniendo la posibilidad de modificar los parámetros del sistema para ajustarse dinámicamente a cada situación. Para esto, el sistema a desarrollar está basado en FPGA, la cual se encargará de la generación de la interferencia adaptada a cada estado. Además, será necesaria la integración de la FPGA junto con el microprocesador, así como el test de las diferentes partes que integran el sistema.Martínez Cuesta, A. (2020). Diseño e implementación de un jammer configurable en FPGA. Universitat Politècnica de València. http://hdl.handle.net/10251/136750TFG
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