http://hdl.handle.net/10366/4645 Sun, 19 Apr 2026 22:52:48 GMT 2026-04-19T22:52:48Z http://hdl.handle.net/10366/163831 An urban scale Eulerian non-reactive multilayer air pollution model is proposed describing convection, turbulent diffusion and emission. A mass-consistent wind field model developed by authors is included in the air pollution model. An Adaptive Finite Element Method with characteristics in the horizontal directions and Finite Differences in the vertical direction using splitting techniques is proposed to numerically solve the corresponding PDE problem. A parallel version of the algorithm improves the precision of the solution keeping computation time below real time of simulation. A numerical example illustrates the whole problem. Wed, 24 Jul 2013 00:00:00 GMT http://hdl.handle.net/10366/163831 2013-07-24T00:00:00Z http://hdl.handle.net/10366/163830 In this article, we focus on a simplified two-dimensional fire model with some three-dimensional effects. The model takes into account the moisture content and the energy lost in the vertical direction and to radiation from the flames. We couple this model with a local wind model, well adapted to fire modelling. The topography, fuel type, mass fraction of the fuel and the meteorological data required by the model (temperature, humidity and wind) are provided by geographic information systems. We incorporate data assimilation techniques to our fire model in order to improve the approximations obtained with the model. The data assimilated are the temperature of the solid fuel (which is related to the position of the fire front) and the mass fraction of fuel at certain points in the domain. The numerical examples show that this procedure is able to correct the approximations obtained by the model simulations, providing more realistic predictions. The process is implemented using parallel computing. Tue, 22 Jul 2014 00:00:00 GMT http://hdl.handle.net/10366/163830 2014-07-22T00:00:00Z http://hdl.handle.net/10366/163829 A global sensitivity analysis and parameter adjustment of a simplified physical fire model applied to a well measured experimental example is developed in order to validate the model. The fire model is a simplified physical 2D wildland fire model with some 3D effects that takes into account the wind, the slope of the orography, the fuel load and type, the moisture content, the energy lost in the vertical direction and the radiation from the flames. The simplicity of the model and the numerical techniques proposed allow very competitive computational times. Tue, 25 Aug 2015 00:00:00 GMT http://hdl.handle.net/10366/163829 2015-08-25T00:00:00Z http://hdl.handle.net/10366/149833 [EN] We use a constituent model to analyze the stability of pentaquark Q qqqq ̄ configurations with a heavy antiquark c ̄ or ̄ b, and four light quarks uuds, ddsu or ssud. The interplay between chromoelectric and chromomagnetic effects is not favorable, and, as a consequence, no bound state is found below the lowest dissociation threshold. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10366/149833 2019-01-01T00:00:00Z http://hdl.handle.net/10366/149831 [EN] Wind speed forecasts obtained by Numerical Weather Prediction models are limited for fine interpretation in heterogeneous terrain, in which different roughnesses and orographies occur. This limitation is derived from the use of low-resolution and grid-box averaged data. In this paper a dynamical downscaling method is presented to increase the local accuracy of wind speed forecasts. The proposed method divides the wind speed forecasting into two steps. In the first one, the mesoscale model WRF (Weather Research and Forecasting) is used for getting wind speed forecasts at specific points of the study domain. On a second stage, these values are used for feeding the HDWind microscale model. HDWind is a local model that provides both a high-resolution wind field that covers the entire study domain and values of wind speed and direction at very located points. As an example of use of the proposed method, we calculate a high-resolution wind field in an urban-interface area from Badajoz, a South-West Spanish city located near the Portugal border. The results obtained are compared with the values read by a weathervane tower of the Spanish State Meteorological Agency (AEMET) in order to prove that the microscale model improves the forecasts obtained by the mesoscale model. Fri, 01 Jan 2021 00:00:00 GMT http://hdl.handle.net/10366/149831 2021-01-01T00:00:00Z http://hdl.handle.net/10366/22464 The aim of the paper is twofold. First, some results of Shiota and Plaza-Martín on Prym varieties of curves with an involution are generalized to the general case of an arbitrary automorphism of prime order. Second, the equations defining the moduli space of curves with an automorphism of prime order as a subscheme of the Sato Grassmannian are given. Wed, 01 Jan 2003 00:00:00 GMT http://hdl.handle.net/10366/22464 2003-01-01T00:00:00Z http://hdl.handle.net/10366/56038 Se presenta una estimación a posteriori del error para el problema parabólico lineal, y se diseña el correspondiente algoritmo de adaptación de malla y paso de tiempo. Para la discretización espacial se utiliza el elemento de Raviart-Thomas de menor orden y para la integración temporal la aproximación de Galerkin discontinua con paso variable. Se aplican los métodos numéricos desarrollados a variosproblemas significativos que muestran la eficiencia del algoritmodesarrollado.; In this paper we present an a-posteriori error estimator for the mixed formulation of a linear parabolic problem, used for designing an efficient adaptive algorithm. Our space-time discretization consists of lowest order Raviart-Thomas finite element over graded meshes and discontinuous Galerkin method with variable time step. Finally, several examples show that the proposed method is efficient and reliable. Wed, 26 Apr 2006 00:00:00 GMT http://hdl.handle.net/10366/56038 2006-04-26T00:00:00Z