Seismic vulnerability analysis of steel buildings in Bogotá, Colombia

A number of mid-height steel buildings have been erected recently in Bogotá. Their seismic risk might be high, given the new microzonation of Bogotá and the lack of previous studies; remarkably, the response reduction factors were commonly obtained from general recommendations. The objective of this work is to investigate the seismic performance of these buildings. This study is carried out on eighteen representative buildings. All these edifices have plan symmetry and are uniform along their height. Span-length: 6 ¿ 8 m; number of floors: 5, 10, 15. Earthquake-resistant systems: moment-resistant frames, concentrically-braced frames and eccentricallybraced frames (using chevron braces). For each building, eight seismic zones have been considered. The vulnerability has been evaluated by “push-over” analyses. In the moment-resistant frames and in the eccentrically-braced frames the nonlinearities are concentrated in the plastic hinges near the connections; in the concentrically-braced frames the nonlinearities are allocated in the braces.Postprint (published version

A structural approach including the behavior of collagen cross-links to model patient-specific human carotid arteries

The final publication is available at Springer via http://dx.doi.org/10.1007/s10439-014-0995-7The objective of this work is to develop a remodeling model for biological matter coupling two different processes in a 3D framework: reorientation of the preferential direction of a given fibered structure and reorientation of the fibrils or filaments that make up such a structure. This work uses the microsphere-based approach to take into account the micro mechanics involved in biological fibered structures regarding both their passive behavior and the reorientation of their micro constituents. Moreover, the macro behavior of the material as a whole is obtained by means of homogenizing the underlying micro response. We associate the orientation space of the integration directions to the physical space of micro-fibrils. To approximate the directional distribution of the fibrils within each fiber bundle, a Bingham probability orientation density function is introduced into the Helmholtz energy function. With all these assumptions, the problem is studied from an energetic point of view, describing the dissipation inherent to remodeling processes, and the evolution equations for both reorientations (change in preferential direction of the network and change in shape of the fibril distribution) re obtained. The model is included in a finite element code which allows computing different geometries and boundary value problems. This results in a complete methodology for characterizing the reorientation evolution of different fibered biological structures, such as cells. Our results show remodeling of fibered structures in two different scales, presenting a qualitatively good agreement with experimental findings in cell mechanics. Hierarchical structures align in the direction of the maximum principal direction of the considered stimulus and narrow in the perpendicular direction. The dissipation rates follows predictable trends although there are no experimental findings to date for comparison. The incorporation of metabolic processes and an insight into cell-oriented mechano-sensing processes can help to overcome the limitations involved.Peer ReviewedPostprint (author's final draft

Graphical identification of TAR models

This paper proposes an automatic procedure to identify Threshold Autoregressive models and specify the threshold values. The proposed procedure is based on recursive estimation of arranged autoregression. The main advantage of the proposed procedure over its competitors is that the threshold values are automatically detected. The performance of the proposed procedure is evaluated using simulations and real data.Nonlinear time series, Recursive estimation, Arranged autoregression, TAR models, Nonlinearity test

Model Predictive Controller for piecewise affine system

2005 IFAC 16th Triennial World Congress, Prague, Czech RepublicThis paper presents a hybrid procedure to solve Model Predictive Controller (MPC) for Piecewise Affine System (PWA) The approach presented here belong to the class of Branch and Bound (B&B) methods. The procedure uses the concepts of reachable set combined to the specific B&B methods, in order to reduce the number of Quadratic Problems (QP) needed to be solved by the optimization algorithm

Tecnologías del Hidrógeno y Pilas de combustible

Conferencias Departamento Ingeniería QuímicaRevisión del desarrollo y aplicación de las tecnologías del hidrógeno como vector energético y su utilización en aplicaciones industriales y comerciales. Las Tecnologías del Hidrógeno y de Pila de Combustible tienen el potencial de contribuir a la reducción de emisiones de gases de efecto invernadero y a la descarbonización de los sectores de energía y transporte en la Unión Europea. Estas tecnologías son parte del Plan Energético Estratégico adoptado por el Consejo Europeo y están en línea con la Comunicación de la Comisión Europea “Energía para una transformación global - Una política energética para Europa”, y el de Iniciativa Tecnológica Conjunta en Pilas de Combustible e Hidrógeno para el periodo 2014 – 2020. Mediante su generación, el hidrógeno permite una mayor introducción de energías renovables en el mix energético dado que este combustible tiene una alta densidad de energía y puede almacenarse sin apenas pérdidas para su uso en gran variedad de aplicaciones entre las cuales destacan: i) combustible para vehículos eléctricos de pila de combustible de hidrógeno; ii) Inyección en la red de gas natural y reinyección en la red eléctrica y aplicaciones en la industria química.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Traducción científico-técnica y traducción audiovisual: análisis de la serie The Big Bang Theory

La traducción científico-técnica constituye un gran porcentaje de la traducción especializada que se lleva a cabo hoy en día en nuestro país. Con el presente trabajo, hemos querido estudiar la traducción de textos científico-técnicos y, a su vez, audiovisuales. De esta manera, hemos definido el texto audiovisual y presentado sus características, una de las cuales es la gran variedad de géneros textuales existentes. Por ello, hemos escogido la comedia de situación The Big Bang Theory (Lorre, 2007), en la que confluyen rasgos característicos del texto audiovisual y del texto científico-técnico. Asimismo, hemos analizado la terminología en ella existente, teniendo en cuenta la categoría gramatical, el campo temático y la estrategia de traducción llevada a cabo, concluyendo que la terminología científico-técnica se caracteriza por estar formada en su mayoría por sustantivos pertenecientes a diferentes campos temáticos de las ciencias y las técnicas, siendo la traducción literal la estrategia más frecuente.Grado en Traducción e Interpretació

Drug resistance in parasitic helminths of veterinary importance in Chile: status review and research needs

The increasing development of anthelmintic resistance (AR) in parasites of livestock is threatening animal health and production worldwide. In Chile, studies evaluating the field efficacy of anthelmintics and the detection of AR have been performed since the 2000s, but until now, no previous attempt has tried to systematise the available information. This article reviews general concepts about AR in helminths of veterinary importance, methods for diagnosis of AR and summarises the published reports of AR in Chile. Anthelmintic resistance in Chile has been reported in gastrointestinal nematodes of horses (benzimidazole resistance) and ruminants (sheep and cattle, macrocyclic lactone and benzimidazole resistance). However, these cases involved a limited number of selected farms and no further conclusions can be made of the status of parasite drug resistance at a regional or national level. No published cases of AR in Fasciola hepatica have been reported in Chilean livestock, but human infections with triclabendazole-resistant F. hepatica have been described in patients with previous consumption of watercress or untreated water from marshes grazed by livestock. Given the zoonotic potential and endemic nature of F. hepatica in Chile, it is urgent to determine the extent of liver fluke resistance. Current research gaps of the situation of AR in Chile and suggestions for the performance of laboratory and field studies are further discussed

Computational modeling of hypertensive growth in the human carotid artery

The final publication is available at Springer via http://dx.doi.org/10.1007/s00466-013-0959-zArterial hypertension is a chronic medical condition associated with an elevated blood pressure. Chronic arterial hypertension initiates a series of events, which are known to collectively initiate arterial wall thickening. However, the correlation between macrostructural mechanical loading, microstructural cellular changes, and macrostructural adaptation remains unclear. Here, we present a microstructurally motivated computational model for chronic arterial hypertension through smooth muscle cell growth. To model growth, we adopt a classical concept based on the multiplicative decomposition of the deformation gradient into an elastic part and a growth part. Motivated by clinical observations, we assume that the driving force for growth is the stretch sensed by the smooth muscle cells. We embed our model into a finite element framework, where growth is stored locally as an internal variable. First, to demonstrate the features of our model, we investigate the effects of hypertensive growth in a real human carotid artery. Our results agree nicely with experimental data reported in the literature both qualitatively and quantitatively.Peer ReviewedPostprint (author's final draft