199 research outputs found

    Presentación [Ciclo de conferencias Cátedra Jorge Juan, Curso 2007-2008]

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    Presentación [Ciclo de conferencias Cátedra Jorge Juan, Curso 2003-2004]

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    Desarrollo de un portal web para la recuperación de librerías DLL

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    Una biblioteca o librería es un compendio de subprogramas utilizado para facilitar el desarrollo del software. Las bibliotecas contienen código y datos que proporcionan servicios a programas independientes, es decir, pasan a formar parte de estos. Esto permite que el código y los datos se compartan y puedan modificarse de forma modular. Una biblioteca o librería de enlace dinámico (DLL) es un archivo propio de Windows que podrá ser llamado desde cualquier aplicación Windows. De hecho, se puede considerar que Windows está construido sobre una gran cantidad de DLL’s. La utilidad de un repositorio de DLL’s radica en que en programación la optimización del tiempo es fundamental, y el primer paso antes de desarrollar cualquier aplicación es investigar si existe un precedente, es decir si ya hay algo hecho en el mismo campo, y si es así aprovecharlo. La segunda utilidad surge porque es relativamente frecuente en Windows que surjan problemas con archivos DLL por razones que veremos, y debido a ello nos veamos en la necesidad de tener que conseguir cierta DLL concreta en un determinado momento porque ha dejado de funcionar una aplicación, o el sistema operativo en el peor de los casos. Este trabajo surge porque aunque actualmente existen algunos repositorios, ninguno facilita una búsqueda completa por todas las propiedades de una DLL, con lo cual actualmente estos archivos no son fácilmente localizables. El objetivo por tanto es la realización de una herramienta que supere a las que actualmente existen en este campo recogiendo lo mejor de cada una, además de ofrecer en lo posible alguna funcionalidad adicional que ninguna ofrezca. Pensamos que el trabajo presentado en efecto cumple con lo expuesto en esta introducción, es decir, por un lado supera funcionalmente a todos los repositorios investigados en el estado del arte, como veremos, y en segundo lugar consideramos que es una herramienta útil tanto para programadores como para usuarios de Windows.Ingeniería Técnica en Informática de Gestió

    Transient thermal response with nonlocal radiation of a blast furnace main trough

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    A mathematical model for the transient thermal behaviour of the main trough of a blast furnace (BF) is presented. The proposed model consists of the transient heat equation with mixed radiation-convection boundary conditions to model the cooling process. The heat equation is coupled with an integral equation posed on the inner boundary, which models the radiative heat exchange on the internal cavity formed by the trough and the refractory cover placed over the trough. The main scope of this work is to address the evolution of the temperature field during a full BF tapping. A reliable algorithm, capable of simulating entire trough campaigns, is presented. The open-source computing platform FEniCS is used to numerically solve the model using a finite element method. A manufactured solution test for the heat diffusion coupled with 2D nonlocal radiation is defined with the purpose of verifying the implementation, comparing the performance of different time discretization schemes and the adaptive time stepping algorithm. Concerning the BF tapping problem, the results show that during the time interval corresponding to a single tapping, the temperature in the radiation enclosure swiftly reaches the steady state value. Nevertheless, to obtain a steady state in the bulk of the solids, much longer time scales are needed due to the large thermal inertia of the structureThis work was partially supported by ERDF and Xunta de Galicia funds under the ED431C 2017/60 and the ED431C 2021/15 grants, by the Ministerio de Ciencia, Innovación y Universidades through the Plan Nacional de I+D+i (MTM2015-68275-R) and the grant BES-2016-077228, and by the Agencia Estatal de Investigación through project [PID2019-105615RB-I00 / AEI / 10.13039/501100011033]S

    Green bionanocomposites based on polyhydroxybutyrate and filled with cellulose nanocrystals: melting processing and characterization

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    Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract]: This article contributes to the understanding of biobased and biodegradable polyhydroxybutyrate (PHB) bionanocomposites melt processed by pre-industrial methods such as extrusion and injection molding and reinforced by weight contents of 1 and 3 wt% of cellulose nanocrystals (CNC) derived from waste streams of the paper industry. Ultrasonic treatment was used for dispersion of the CNC, which was followed by transmission electron microscopy. The thermal properties and the crystallization behavior of bionanocomposites were studied by thermogravimetric analysis, differential scanning analysis, X-ray diffraction and polarized optical microscopy. Investigations on the bending properties were carried out in conjunction with the analysis of their dynamic mechanical behavior. Scanning electron microscopy was used to characterize the fracture surface. All these analyses give a deep insight into their structure-property relationship. The moisture absorption measurements and gas barrier properties analysis made to the processed bionanocomposites have provided an insight into their behavior under environmental conditions. The PHB bionanocomposites with a low content of 1 wt% CNC were found to have the best dispersion quality, which had a positive effect on almost all mechanical and thermal properties. The increase in crystallinity with the incorporation of CNC also contributed to an improvement in mechanical properties. In ddition, the bionanocomposites show a slightly lower tendency to absorb moisture and better barrier properties to oxygen and water vapor. These findings showed that these bionanocomposites are suitable for use in the packaging industry.Xunta de Galicia. Consellería de Cultura, Educación, Formación Profesional e Universidades; : ED-431 C 2019/

    Severe Plasmodium vivax malaria exhibits marked inflammatory imbalance

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    <p>Abstract</p> <p>Background</p> <p>Despite clinical descriptions of severe vivax malaria cases having been reported, data regarding immunological and inflammatory patterns are scarce. In this report, the inflammatory and immunological status of both mild and severe vivax malaria cases are compared in order to explore immunopathological events in this disease.</p> <p>Methods and Results</p> <p>Active and passive malaria case detections were performed during 2007 in Buritis, Rondônia, in the Brazilian Amazon. A total of 219 participants enrolled the study. Study individuals were classified according to the presence of <it>Plasmodium vivax </it>infection within four groups: non-infected (n = 90), asymptomatic (n = 60), mild (n = 50) and severe vivax infection (n = 19). A diagnosis of malaria was made by microscopy and molecular assays. Since at present no clear criteria define severe vivax malaria, this study adapted the consensual criteria from falciparum malaria. Patients with severe <it>P. vivax </it>infection were younger, had lived for shorter time in the endemic area, and recalled having experienced less previous malaria episodes than individuals with no malaria infection and with mild or asymptomatic infection. Strong linear trends were identified regarding increasing plasma levels of C reactive protein (CRP), serum creatinine, bilirubins and the graduation of disease severity. Plasma levels of tumour necrosis factor (TNF), interferon-gamma(IFN-gamma) and also IFN-gamma/interleukin-10 ratios were increased and exhibited a linear trend with gradual augmentation of disease severity. Both laboratory parameters of organ dysfunction and inflammatory cytokines were reduced during anti-parasite therapy in those patients with severe disease.</p> <p>Conclusion</p> <p>Different clinical presentations of vivax malaria infection present strong association with activation of pro-inflammatory responses and cytokine imbalance. These findings are of utmost importance to improve current knowledge about physiopathological concepts of this serious widespread disease.</p

    Influence of the Hydrophilicity of Montmorillonite on Structure and Properties of Thermoplastic Wheat Starch/Montmorillonite Bionanocomposites

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    Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] The increasing environmental pollution with petroleum-based plastics has advanced research on biodegradable polymers. Thermoplastic starch (TPS) is one promising candidate due to wide availability from various renewable sources, low cost and biodegradability. However, TPS has significant shortcomings, as high water sensitivity and low mechanical properties. An approach to overcome these drawbacks is adding nanofillers as reinforcement of the starch matrix. Among the nanofillers, montmorillonite clays have the advantages of a wide availability, low cost, versatility and environmental friendliness. Bionanocomposites based on wheat starch plasticized with glycerol and reinforced with three types of montmorillonite nanoclays, one natural (Cloisite Na+) and two organomodified (Cloisite 30B and Cloisite 10A), were prepared by melt processing. The effect of nanoclay type and amount on processing properties, thermal stability, dynamic mechanical properties and water absorption was widely investigated. The properties strongly depended on the dispersion state of the nanoclay in the TPS matrix. The dispersion improved with the hydrophilicity of the nanoclay. Cloisite Na+, the most hydrophilic nanoclay, was the most effective in reinforcing TPS, improving the thermal stability and the dynamic mechanical properties, and showing a greater resistance to water absorption in normal humidity environments. Bionanocomposites of TPS andCloisite Na+ can be a good alternative for use in packaging applications.Xunta de Galicia; ED431C 2019/1

    Comportamiento de cristalización y fusión en compuestos de polipropileno y derivados de madera

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    [Resumen] Se ha analizado el comportamiento de cristalización bajo condiciones dinámicas e isotermas, y de fusión, del polipropileno isotáctico, iPP, como matriz semicristalina en compuestos binarios con polvo de madera, WF, a composiciones del 20% en peso de refuerzo vegetal, iPP/WF 80/20, y ternarios, iPP/WF/I, mediante la incorporación de un agente de interfase basado en un copolímero de etileno/ácido metacrílico, preparados mediante mezclado en fundido en extrusora de doble husillo. Tanto en el compuesto binario como en los compatibilizados o ternarios, el iPP presenta el polimorfo cristalino monoclínico α, independientemente de si la cristalización se realiza en condiciones dinámicas desde el fundido a velocidades de enfriamiento entre 1 y 20 grado.min-1, o en condiciones isotermas. La presencia del componente vegetal induce un ligero efecto nucleante sobre la cristalización isoterma del iPP, que se manifiesta en una disminución de las energías libres interfaciales basales y de la energía libre de nucleación y, por lo tanto, en un aumento de la velocidad global de cristalización. Por el contrario, la incorporación del agente de interfase, genera un fenómeno de compatibilización que se traduce en una disminución de la temperatura de cristalización del iPP, en un aumento de las energías libres interfaciales basales respecto del compuesto binario y, por lo tanto, en una reducción de la velocidad global de cristalización. Tanto en el caso del compuesto binario como en los ternarios, el comportamiento de fusión del iPP es función del subenfriamiento del sistema y no se ve prácticamente alterado por la presencia de la carga vegetal y del agente de interfase
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