XLIII Olimpiada matemática española

Depto. de Análisis Matemático y Matemática AplicadaFac. de Ciencias MatemáticasTRUEpu

Diseño, cálculo, fabricación y evaluación de la conformidad de una cisterna destinada al transporte de mercancías peligrosas

El objeto del presente proyecto técnico es el diseño, cálculo, fabricación y evaluación de la conformidad(marcado CE) de una cisterna para su acoplamiento en el bastidor de un camión, destinado al transporte de mercancías peligrosas por el territorio de la unión europea , regulado por el ADR 2013. La cisterna esta destinada concretamente al transporte de acetona, liquido peligroso de clase III.Escuela Técnica Superior de Ingeniería IndustrialUniversidad Politécnica de Cartagen

Concurso de primavera: una idea para todos

Depto. de Análisis Matemático y Matemática AplicadaFac. de Ciencias MatemáticasTRUEpu

Una biografía de Puig Adam

Depto. de Análisis Matemático y Matemática AplicadaFac. de Ciencias MatemáticasTRUEpu

Analysis of heat and smoke propagation and oscillatory flow through ceiling vents in a large-scale compartment fire

One question that often arises is whether a specialized code or a more general code may be equally suitable for fire modeling. This paper investigates the performance and capabilities of a specialized code (FDS) and a general-purpose code (FLUENT) to simulate a fire in the commercial area of an underground intermodal transportation station. In order to facilitate a more precise comparison between the two codes, especially with regard to ventilation issues, the number of factors that may affect the fire evolution is reduced by simplifying the scenario and the fire model. The codes are applied to the same fire scenario using a simplified fire model, which considers a source of mass, heat and species to characterize the fire focus, and whose results are also compared with those obtained using FDS and a combustion model. An oscillating behavior of the fire-induced convective heat and mass fluxes through the natural vents is predicted, whose frequency compares well with experimental results for the ranges of compartment heights and heat release rates considered. The results obtained with the two codes for the smoke and heat propagation patterns and convective fluxes through the forced and natural ventilation systems are discussed and compared to each other. The agreement is very good for the temperature and species concentration distributions and the overall flow pattern, whereas appreciable discrepancies are only found in the oscillatory behavior of the fire-induced convective heat and mass fluxes through the natural vents. The relative performance of the codes in terms of central processing unit (CPU) time consumption is also discussed.This research was funded by Consorcio Regional de Transportes de Madrid, grant number OTRI-FUNED 5510003256. The support of the Consorcio Regional de Transportes de Madrid is gratefully acknowledged

Numerical simulation of free surface flows in die casting injection processes

This paper presents a numerical study of the flow of molten metal in the shot sleeve of horizontal high-pressure die-casting machines during the injection process. The analysis of the wave of molten metal created by plunger motion can be of help in reducing porosity in manufactured parts caused by entrapment in the molten metal of a certain amount of the initial air in the die cavity and in the shot sleeve. The amount of trapped air can be reduced by selecting appropriate operating conditions during the injection process, which are mainly determined by the law of plunger motion, the initial shot sleeve filling fraction, and the geometrical characteristics of the shot sleeve. The proposed model, which considers the problem as two-dimensional, is based on the conservation equations of mass and momentum, and treats the free surface using a capturing method (Scalar Equation Method). Surface tension and solidification effects are neglected. Different approaches are considered to simulate plunger motion, in which either the plunger surface or the end wall of the sleeve moves and contracts a Cartesian grid. In the second case, a horizontal body force per unit mass is introduced and the plunger is assumed to be at rest. When numerical results for the wave profile were compared with those obtained using an analytical model based on the shallow-water approximation, and also with numerical results obtained from a CFD code specifically designed for free-surface flow modeling, a good degree of agreement was found.The authors gratefully acknowledge the support of the Spanish Comisión Interministerial de Ciencia y Tecnología (CICYT) under grants TAP97-0489 and PB98-0007

Los etolios en Numancia

Se describen diez balas de hondas (glandes fundae, molíbdaina) procedentes de Numancia y sus alrededores; algunas aparecieron en las excavaciones realizadas en ese yacimiento a comienzos del siglo XX y el resto, de diversos lugares asociados con las operaciones militares del asedio (134-133 a.C.). El rasgo común de todas esas balas es que portan la leyenda en griego “de los Etolios”, lo que plantea el interesante problema de cuándo y cómo una tropa de honderos de un ethnos griegos pudo acabar combatiendo en la otra punta del Mediterráneo. El artículo examina las circunstancias de la Liga Etolia a mediados del s. II a.C. y concluye que, en base a la mayor evidencia disponible, los honderos posiblemente formaron parte del ejército de P. Cornelio Escipión Emiliano

T-Norm y desajuste léxico y acústico en reconocimiento de locutor dependiente de texto

Actas de las V Jornadas en Tecnología del Habla (JTH 2008)Este trabajo presenta un estudio extenso sobre T-norm aplicado a Reconocimiento de Locutor Dependiente de Texto, analizando también los problemas del desajuste léxico y acústico. Veremos cómo varían los resultados teniendo en cuenta la dependencia de género y realizando T-norm a nivel de frase, fonema y estado con cohortes de impostores de distintos tamaños. El estudio demuestra que implementar T-norm por fonema o estado puede llegar a conseguir mejoras relativas de hasta un 16% y que realizar una selección de cohorte basada en el género puede mejorar más aún los resultados con respecto al caso independiente de género

Bacteraemia due to Escherichia coli producing extended-spectrum beta-lactamases (ESBL): clinical relevance and today’s’ insights

©2011 Sociedad Española de Quimioterapia. This manuscript version is made available under the BY-NC 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/. This document is the Published, version of a Published Work that appeared in final form in Revista Española de Quimioterapia.RESUMEN: La resistencia bacteriana es un problema antiguo pero de gran actualidad, ya que en un marco de “austeridad” en cuanto al número de nuevas moléculas de antibiótico disponibles en el mercado, la presencia de microorganismos multirresistentes es cada vez más frecuente. E. coli es el microorganismo más frecuentemente implicado en bacteriemias nosocomiales y comunitarias, y el aislamiento de cepas productoras de BLEE se sitúa en torno al 10% en nuestro país. Las infecciones por E. coli con BLEE han experimentado importantes cambios epidemiológicos en los últimos tiempos y actualmente la atención se centra en el aumento de infecciones y colonizaciones en pacientes procedentes de la comunidad, sobre todo en relación con instituciones sanitarias, y la mayor incidencia de las CTX-M frente a otros tipos de BLEE. El papel de estas enzimas como factor de virulencia que aumente por sí mismo la mortalidad en los pacientes con bacteriemia por E. coli no queda claro. La principal repercusión clínica de las BLEE parece ser la mayor frecuencia con la que estos pacientes con infecciones graves reciben un tratamiento empírico inadecuado, de ahí la importancia de identificar qué factores predicen la presencia de una cepa con BLEE para poder ofrecer un tratamiento adecuado lo antes posible. En cuanto a las medidas de control de la diseminación de BLEE, la eficacia del aislamiento de contacto y la actuación frente a pacientes colonizados por E. coli con BLEE no están claras, pero es incuestionable la necesidad de implementar un uso correcto y responsable de los antibióticos para evitar la expansión de cepas resistentes.ABSTRACT: Antibiotic resistance is an old problem with new face as the rate of infections due to multidrug resistant bacteria is higher everyday and the number of new antibiotics to overwhelm the problem is becoming smaller. E. coli is the most frequent agent causing nosocomial or community-acquired bacteraemia being in our country 10% of them extended-spectrum betalactamases (ESBL) producing E. coli isolates. Nowadays the number of community-acquired or health-related infections caused by these ES-BL producing E. coli is increasing. CTX-M has also become the most frequent ESBL compared to other enzymes. The role of these enzymes as a virulence factor increasing mortality in patients with bacteraemia due to E. coli is not well defined. The relevance of ES-BL-E. coli seems to be related with the higher frequency of inadequate treatment and therefore the importance of identifying factors or features that might predict that the patient’s infection is due to one of these isolates. In terms of prevention and control of infection measures, the role of patient’s isolation is not clear but a proper prescription of antibiotics and antibiotic control policies are probably important to reduce the problem

A new isosurface extraction method on arbitrary grids

The development of interface-capturing methods (such as level-set, phase-field or volume of fluid (VOF) methods) for arbitrary 3D grids has further highlighted the need for more accurate and efficient interface reconstruction procedures. In this work, we propose a new method for the extraction of isosurfaces on arbitrary polyhedra that can be used with advantage for this purpose. The isosurface is extracted from volume fractions by a general polygon tracing procedure, which is valid for convex or non-convex geometries, even with non-planar faces. The proposed method, which can be considered as an extension of the marching cubes technique, produces consistent results even for ambiguous situations in polyhedra of arbitrary shape. To show the reproducibility of the results presented in this work, we provide the open source library isoap, which has been developed to implement the proposed method and includes test programs to demonstrate the successful extraction of isosurfaces on several grids with polyhedral cells of different types. We present results obtained not only for isosurface extraction from discrete volume fractions resulting from a volume of fluid method, but also from data sets obtained from implicit mathematical functions and signed distances to scanned surfaces. The improvement provided by the proposed method for the extraction of isosurfaces in arbitrary grids will also be very useful in other fields, such as CFD visualization or medical imaging.The authors gratefully acknowledge the support of the Spanish Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación and FEDER through projects DPI2017-87826-C2-1-P and DPI2017-87826-C2-2-P