154 resultados para Joaquim Sapinho
Resumo:
Objectius: Determinar l’epidemiologia de la Sarcoïdosi a Osona. I descriure’n les característiques clíniques. Material i mètodes: Identificació i selecció de casos de Sarcoïdosi al nostre centre, entre 1983-2011. Revisió retrospectiva, recollida i anàlisi. Resultats: Incidència 2.12 casos/105habitants/any. n = 55. Predomini femení (69%), edat mitjana 47.8 anys. Clínica més freqüent: simptomatologia general. Patrons radiològics més freqüents: Estadi I-II. Biòpsia transbronquial: tècnica més utilitzada. Retard diagnòstic 5.9 mesos i mortalitat relacionada 7.6%. Conclusions: Incidència superior a la publicada a Catalunya. Predomini femení, amb diagnòstic més tardà que en homes. Presentació clínica predominant: síndrome Löfgren. Notable retard diagnòstic i baixa mortalitat.
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El projecte té per objecte elaborar i desenvolupar una fulla de càlcul la qual enspermeti estudiar, controlar i fer el seguiment de pressupostos en obres deconstrucció tan a nivell de contractació privada com de contractació pública.La idea d’elaborar aquest projecte va sorgir com a conseqüència de lanecessitat que sovint tenim tant els alumnes com els arquitectes tècnics, a l’horade poder confeccionar pressupostos, descomposats i poder controlar aquestspressupostos un cop sortim de la universitat, sense tenir un gran coneixementdels programes que existeixen en el mercat. Aquesta necessitat sorgeix quanvolem enfocar la nostra tasca professional al món de l’empresa constructora.La necessitat de poder fer descomposats i controlar totes i cadascuna de lesparts de que està composat un preu d’un pressupost, no la trobava en cap delsprogrames existents en el mercat, tipus Presto, TCQ 2000, Arquimedes, ja queaquests programes informàtics, si que realitzen els descomposats i es veuen,però en cap moment, si no es fa de forma manual, es pot arribar a saber elcost només de mà d’obra, o bé el de material, ja que el valor monetari que surtés el total de tots els costos directes
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En l’àmbit de la indústria metal·lúrgica és molt freqüent l’ús de tècniques de conformació per deformació (treball en fred o en calent) per tal de donar forma, a metalls o aliatges metàl·lics. Mecànicament, el treball en fred provoca l’increment de la duresa i de la resistència a la tensió i, per contra, la reducció de la ductilitat, de la conductivitat elèctrica i de la resistència a la corrosió. Per tal de millorar les propietats mecàniques afectades per la reducció és on pren rellevància l’ús de la recuita. La recuita és un tractament tèrmic format per tres etapes: la recuperació, la recristal·lització i el creixement del gra. En el present projecte analitzem en detall la recuperació. El projecte té com a objectiu fer l’estudi experimental de la cinètica, durant la recuita de recuperació, d’un aliatge mecànic. Aquest estudi permetrà determinar els paràmetres més rellevants per tal de descriure com evolucionen l’estructura i les propietats del metall durant un tractament tèrmic, en funció del temps de tractament i la temperatura
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The speed of front propagation in fractals is studied by using (i) the reduction of the reaction-transport equation into a Hamilton-Jacobi equation and (ii) the local-equilibrium approach. Different equations proposed for describing transport in fractal media, together with logistic reaction kinetics, are considered. Finally, we analyze the main features of wave fronts resulting from this dynamic process, i.e., why they are accelerated and what is the exact form of this acceleration
Resumo:
The effect of initial conditions on the speed of propagating fronts in reaction-diffusion equations is examined in the framework of the Hamilton-Jacobi theory. We study the transition between quenched and nonquenched fronts both analytically and numerically for parabolic and hyperbolic reaction diffusion. Nonhomogeneous media are also analyzed and the effect of algebraic initial conditions is also discussed
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Why does not gravity make drops slip down the inclined surfaces, e.g., plant leaves? The current explanation is based on the existence of surface inhomogeneities, which cause a sustaining force that pins the contact line. Following this theory, the drop remains in equilibrium until a critical value of the sustaining force is reached. We propose an alternative analysis, from the point of view of energy balance, for the particular case in which the drop leaves a liquid film behind. The critical angle of the inclined surface at which the drop slips down is predicted. This result does not depend explicitly on surface inhomogeneities, but only on the drop size and surface tensions. There is good agreement with experiments for contact angles below 90° where the formation of the film is expected, whereas for greater contact angles great discrepancies arise
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La fibrosi retroperitoneal peritoneal és una entitat clínica infreqüent,l’etiologia roman desconeguda en 2/3 dels casos. Es una inflamació crònica amb fibrosi del teixit retroperitoneal envoltant grans vasos, urèters i òrgans abdominals. Actualment el pronòstic ha millorat amb el tractament immunosupressor i la cirurgia. Presentem una revisió dels pacients diagnosticats en el nostre centre de FRP idiopàtica amb l’objectiu de revisar les característiques clíniques, l’afectació orgànica, troballes de laboratori i radiològiques, el tractament rebut i el seguiment de l’evolució clínica. El tractament va ser la corticoteràpia acompanyada de cirurgia. En el seguiment posterior, les recidives van ser freqüents.
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The front speed of the Neolithic (farmer) spread in Europe decreased as it reached Northern latitudes, where the Mesolithic (huntergatherer) population density was higher. Here, we describe a reaction diffusion model with (i) an anisotropic dispersion kernel depending on the Mesolithicpopulation density gradient and (ii) a modified population growth equation. Both effects are related to the space available for the Neolithic population. The model is able to explain the slowdown of the Neolithic front as observed from archaeological data
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Most integrodifference models of biological invasions are based on the nonoverlapping-generations approximation. However, the effect of multiple reproduction events overlapping generations on the front speed can be very important especially for species with a long life spam . Only in one-dimensional space has this approximation been relaxed previously, although almost all biological invasions take place in two dimensions. Here we present a model that takes into account the overlapping generations effect or, more generally, the stage structure of the population , and we analyze the main differences with the corresponding nonoverlappinggenerations results
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A kinetic model is derived to study the successive movements of particles, described by a Poisson process, as well as their generation. The irreversible thermodynamics of this system is also studied from the kinetic model. This makes it possible to evaluate the differences between thermodynamical quantities computed exactly and up to second-order. Such differences determine the range of validity of the second-order approximation to extended irreversible thermodynamics
Resumo:
The radiation distribution function used by Domínguez and Jou [Phys. Rev. E 51, 158 (1995)] has been recently modified by Domínguez-Cascante and Faraudo [Phys. Rev. E 54, 6933 (1996)]. However, in these studies neither distribution was written in terms of directly measurable quantities. Here a solution to this problem is presented, and we also propose an experiment that may make it possible to determine the distribution function of nonequilibrium radiation experimentally. The results derived do not depend on a specific distribution function for the matter content of the system
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A generalization of reaction-diffusion models to multigeneration biological species is presented. It is based on more complex random walks than those in previous approaches. The new model is developed analytically up to infinite order. Our predictions for the speed agree to experimental data for several butterfly species better than existing models. The predicted dependence for the speed on the number of generations per year allows us to explain the change in speed observed for a specific invasion
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The front speed problem for nonuniform reaction rate and diffusion coefficient is studied by using singular perturbation analysis, the geometric approach of Hamilton-Jacobi dynamics, and the local speed approach. Exact and perturbed expressions for the front speed are obtained in the limit of large times. For linear and fractal heterogeneities, the analytic results have been compared with numerical results exhibiting a good agreement. Finally we reach a general expression for the speed of the front in the case of smooth and weak heterogeneities
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We present an approach to determining the speed of wave-front solutions to reaction-transport processes. This method is more accurate than previous ones. This is explicitly shown for several cases of practical interest: (i) the anomalous diffusion reaction, (ii) reaction diffusion in an advective field, and (iii) time-delayed reaction diffusion. There is good agreement with the results of numerical simulations
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The asymptotic speed problem of front solutions to hyperbolic reaction-diffusion (HRD) equations is studied in detail. We perform linear and variational analyses to obtain bounds for the speed. In contrast to what has been done in previous work, here we derive upper bounds in addition to lower ones in such a way that we can obtain improved bounds. For some functions it is possible to determine the speed without any uncertainty. This is also achieved for some systems of HRD (i.e., time-delayed Lotka-Volterra) equations that take into account the interaction among different species. An analytical analysis is performed for several systems of biological interest, and we find good agreement with the results of numerical simulations as well as with available observations for a system discussed recently