31 research outputs found
Influencia de la interacción suelo-estructura en el comportamiento dinámico de puentes sometidos al paso de trenes de alta velocidad
Esta tesis se enmarca dentro del estudio del comportamiento dinámico de puentes de ferrocarril derivado del paso sobre ellos de trenes a grandes velocidades. Tiene una clara vocación práctica ya que, partiendo de la investigación de la influencia de la interacción suelo-estructura en el fenómeno vibratorio involucrado, propone las pautas a seguir en la confección de modelos que permitan caracterizar la respuesta de puentes reales para su diseño o actualización.
En el desarrollo de la misma se determina, mediante los correspondientes estudios paramétricos, la influencia de las principales variables implicadas en el comportamiento dinámico del puente: la modelización estructural, tipo de análisis, tamaño de la zona de terreno a modelizar, tamaño de los elementos, etc.
A partir de modelos confeccionados siguiendo dichas pautas se pone de relieve la importancia que adquiere en el análisis la interacción suelo-estructura.
Se realiza una verificación de la metodología en base a un ensayo experimental a fin de validar la precisión del método.
Con dicha metodología se realiza un estudio pormenorizado del comportamiento de viaductos de luces pequeñas que son especialmente sensibles a los fenómenos resonantes
A Finite Element‑Based Methodology for the Thermo‑mechanical Analysis of Early Age Behavior in Concrete Structures
This paper presents a general procedure based on fracture mechanics models in order to analyze the level of cracking
and structural safety in reinforced concrete elements at early ages, depending on the stripping time. Our procedure
involves the development of a thermo-mechanical numerical model based on the finite element method that
accounts for the change in the mechanical properties of concrete with time. Moreover, fracture mechanisms are
analyzed by means of a material damage model, which is characterized via specific experimental results obtained for
standard specimens and notched beams under three-point bending testing. The loading conditions are both thermal
and mechanical, and are obtained from the hydration process for a given concrete dosage. The presented methodology
allows for the determination of the optimal stripping time, whereas it helps assessing the analysis of the cracking
and the stress states of the elements under consideration. A practical application, namely the analysis of a retaining
wall, is used to validate our methodology, showing its suitability in engineering practice.Ministerio de Economía y Competitividad BIA2016-75431-
Analysis of the Utilization of Air-Cooled Blast Furnace Slag as Industrial Waste Aggregates in Self-Compacting Concrete
In this work, the effects of replacing the aggregates of self-compacting concrete by air-cooled blast furnace slag have been analysed. Different mixes have been manufactured by substituting the fine and coarse natural aggregates by air-cooled blast furnace slag. The fracture energy and the tensile and compressive strength have been determined for each mix. The self-compacting properties of the mixes, or the absence of them, have been observed. The main goals of this research are the decrease of the price of aggregates, reduction of the industrial waste, and attenuation the rate of
consumption of natural resources. The results show that the self-compactability of the concrete is gradually lost as the slag content is increased, thus, when the ratio of replacement is low, the concrete keeps the self-compacting properties. Nevertheless, the loss of self-compaction affects the mechanical properties by increasing its strength. An air-cooled blast furnace slag did not present problems of heavy metals leaching.Ministerio de Economía y Competitividad BIA2016-75431-RUniversidad de Sevilla VI Plan Propio de Investigació
Energy Reconstruction of Electromagnetic Showers from π0 Decays with the ICARUS T600 Liquid Argon TPC
We discuss the ICARUS T600 detector capabilities in electromagnetic shower reconstruction through the analysis of a sample of 212 events, coming from the 2001 Pavia surface test run, of hadronic interactions leading to the production of π0 mesons. Methods of shower energy and shower direction measurements were developed and the invariant mass of the photon pairs was reconstructed. The (γ,γ) invariant mass was found to be consistent with the value of the π0 mass. The resolution of the reconstructed π0 mass was found to be equal to 27.3%. An improved analysis, carried out in order to clean the full event sample from the events measured in the crowded environment, mostly due to the trigger conditions, gave a π0 mass resolution of 16.1%, significantly better than the one evaluated for the full event sample. The trigger requirement of the coincidence of at least four photo-multiplier signals favored the selection of events with a strong pile up of cosmic ray tracks and interactions. Hence a number of candidate π0 events were heavily contaminated by other tracks and had to be rejected. Monte Carlo simulations of events with π0 production in hadronic and neutrino interactions confirmed the validity of the shower energy and shower direction reconstruction methods applied to the real data.We are glad of the financial and technical support of our funding agencies and
in particular of the Istituto Nazionale di Fisica Nucleare (INFN). The Polish
groups acknowledge the support of the Ministry of Science and Higher Education
in Poland, 105,160,620,621/E-344,E-340,E-77,E-78/SPB/ICARUS/
P-03/DZ211-214/2003-2008, 1P03B04130 and N N202 0299 33
Aplicación a la docencia en ingeniería de las estructuras de las nuevas metodologías adaptadas al plan de Bolonia
La adaptación de los nuevos planes de estudio al Plan de Bolonia es hoy día un hecho que se está materializando
en la implantación de los nuevos títulos de Grado y Máster en las distintas universidades españolas. En
particular, en la Escuela Técnica Superior de Ingeniería de la Universidad de Sevilla, dieron comienzo los
nuevos títulos de Grado en el presente curso académico 2010-11. Por otro lado, las asignaturas comúnmente
clasificadas dentro del área de conocimiento de Ingeniería de las Estructuras son asignaturas de carácter
tecnológico impartidas en los últimos años de las distintas titulaciones en las que se imparte docencia. En este
contexto se engloba el presente proyecto. En este trabajo se presentan nuevas metodologías aplicadas y técnicas
docentes, las cuales implican nuevos criterios de evaluación, así como un enfoque eminentemente práctico de
las clases teóricas que incluyen prácticas de campo y visitas a instalaciones reales. Los principales resultados
observados de estas nuevas técnicas docentes son una mayor motivación e interés del alumno en la asignatura,
así como una mayor interacción profesor-alumno. Todo ello son objetivos fundamentales que plantean los
nuevos planes de estudio en el marco actual
Interleukin-10 polymorphisms in Spanish IgA deficiency patients: a case-control and family study
BACKGROUND: IgA deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. Genetic and environmental factors are suspected to be involved in the development of the disease. Interleukin-10 (IL-10) is a cytokine with stimulatory activity on immunoglobulin production and it may be an important regulator in IgAD pathogenesis. The IL-10 gene contains several single nucleotide polymorphisms (SNPs) and two polymorphic microsatellites located in the 5'-flanking region. Our aim was to ascertain if any of these polymorphic markers are associated or linked to IgAD in Spanish patients. METHODS: We genotyped 278 patients with IgAD and 573 ethnically matched controls for the microsatellites IL-10R and IL-10G and for three single nucleotide polymorphisms at positions -1082, -819 and -592 in the proximal promoter of the gene. We also included in this study the parents of 194 patients in order to study the IL-10 haplotypes transmitted and not transmitted to the affected offspring. RESULTS: The only allele where a significant difference was observed in the comparison between IgA deficiency patients and controls was the IL-10G12 allele (OR = 1.58 and p = 0.021). However, this p value could not withstand a Bonferroni correction. None of the IL-10R or promoter SNP alleles was found at a different frequency when patients were compared with controls. CONCLUSION: Our data do not show any significant difference in IL-10 polymorphism frequencies between control and IgAD patient samples. Their haplotype distribution among patients and controls was also equivalent and therefore these microsatellites and SNPs do not seem to influence IgAD susceptibility
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
A Finite Element‑Based Methodology for the Thermo‑mechanical Analysis of Early Age Behavior in Concrete Structures
This paper presents a general procedure based on fracture mechanics models in order to analyze the level of cracking
and structural safety in reinforced concrete elements at early ages, depending on the stripping time. Our procedure
involves the development of a thermo-mechanical numerical model based on the finite element method that
accounts for the change in the mechanical properties of concrete with time. Moreover, fracture mechanisms are
analyzed by means of a material damage model, which is characterized via specific experimental results obtained for
standard specimens and notched beams under three-point bending testing. The loading conditions are both thermal
and mechanical, and are obtained from the hydration process for a given concrete dosage. The presented methodology
allows for the determination of the optimal stripping time, whereas it helps assessing the analysis of the cracking
and the stress states of the elements under consideration. A practical application, namely the analysis of a retaining
wall, is used to validate our methodology, showing its suitability in engineering practice.This work has been developed within the framework of activities of the Research and Development project: "T3CI: Technology for curing control infrastructure construction" funded by the CDTI and sponsored by AZVI Inc., Aertec Ingenieria y Desarrollo Inc. and Geolen Ingenieria Inc. A partial financial support was also provided for this research by the Spanish Ministry of Economy and Competitiveness under Project BIA2016-75431-R
Analysis of the Behavior of Very High Strength Concrete Subjected to Thermal Shock Loading
Creative Commons License (CC BY-NC-ND 3.0)En este trabajo se analiza el comportamiento mecánico de hormigones de muy alta resistencia, reforzados con fibras, tras haber sido expuestos a cargas de choque térmico. Se analizan dos tipos de hormigones, uno sin ningún tipo de fibra (hormigón de control) y otro reforzado con fibras de acero y de polipropileno. Estos hormigones se han sometido a un proceso de calentamiento hasta 300ºC y se han enfriado de distintas formas, desde enfriamiento lento en el interior del horno, a enfriamiento rápido en aire y agua. De esta forma, se analiza la influencia de la velocidad de aplicación de las cargas de enfriamiento sobre sus propiedades mecánicas.This paper analyzes the mechanical behavior of very high strength concrete, reinforced with fibers, after being exposed to thermal shock loads. Two types of concrete are analyzed, one without any fiber (control concrete) and another reinforced with steel and polypropylene fibers. These concretes have undergone a heating process up to 300°C and have cooled in different ways, from slow cooling inside the oven to rapid cooling in air and water. In this way, the influence of the application speed of cooling loads on their mechanical properties is analyzed