Modelado de diferentes tipos de cinturones de seguridad y estudio de su efecto en caso de colisión frontal mediante LS-DYNA

El objetivo principal de este proyecto es desarrollar, a partir de un modelo de simulación de choque frontal formado por un conductor y un asiento, varios casos con diferentes tipos de cinturones de seguridad, mediante el procesador de elementos finitos LS-DYNA. También es objetivo de este proyecto demostrar la diferencia de efectividad de diferentes tipos de cinturones de seguridad, dependiendo de su anclaje en dos, tres o cuatro puntos. Por último, se evalúa el aumento de efectividad combinando el cinturón de seguridad de tres puntos con el airbag. Todos los resultados se obtienen con la aplicación de LS-DYNA, LS-PrePost. Debido a la complejidad de LS-DYNA y LS-PrePost el modelo de simulación que se desarrolla en este proyecto es sencillo, en el cuál se pretende representar las características más generales del suceso. LS-DYNA tiene en cuenta una gran cantidad de fenómenos para las simulaciones: comportamiento no lineal, algoritmos de contacto, fricción, transferencia de calor entre partes, y un largo etc.… No es objeto de este proyecto entrar en detalle de ninguno de los procesos que participan en la simulación, como por ejemplo, el llenado del airbag. Los valores asignados a los distintos parámetros que participan en los distintos procesos son valores típicos que se han encontrado en la literatura consultada. Sí es objeto de este proyecto modificar arbitrariamente alguno de estos parámetros para ver su repercusión en los resultados, por lo que se estudian tres casos distintos a partir del mismo modelo de simulación, y un modelo de simulación más complejo para la combinación del cinturón de seguridad más el airbag.Ingeniería Técnica en Mecánic

The relationship between EFQM levels of excellence and CSR development

Purpose The purpose of this paper is to analyse the level of corporate social responsibility (CSR) development, in accordance with the dimensions of Maon et al.’s (2010) model, which could be achieved when organisations adopt the EFQM model, as well as how the EFQM model can foster this CSR development. Design/methodology/approach The research method chosen was a qualitative methodology involving multiple case studies. The empirical research relies on an in-depth study of four cases of organisations recognised by the EFQM model in Spain. Findings The findings show that, although a higher commitment to the EFQM model implies a greater level of CSR development, with the knowledge and attitudinal dimensions more developed than others, organisations still have to make CSR an internalised management ideology. Research limitations/implications The very nature of the process of EFQM assessment does not ensure uniformity in all aspects of management. Limitations that are inherent to case studies: factors that can be chosen by the researcher, such as geographical location, size, sector and ownership, can have an influence on the characteristics of the CSR practices that are found. Practical implications This study contributes to the literature on excellence by approaching the EFQM model as a tool to integrate CSR issues into management. Social implications A relationship between commitment to excellence and CSR development does exist. Originality/value To the best of the authors’ knowledge, no previous analysis has been performed to address the potential relationship between CSR development in accordance with Maon et al.’s (2010) model and commitment to excellence

Thermal conductivity reduction in thermoelectric nanowires

Comunicación presentada en la 12th European Conference on Thermoelectricity (ECT2014), celebrada en Madrid del 24 al 26 de septiembre de 2014.Peer Reviewe

Ordered three-dimensional interconnected nanoarchitectures in anodic porous ​alumina

Three-dimensional (3D) nanostructures combine properties of nanoscale materials with the advantages of being macro-sized pieces when the time comes to manipulate, measure their properties or make a device. However, the amount of compounds with the ability to self-organize in ordered 3D nanostructures is limited. Therefore, template-based fabrication strategies become the key approach towards 3D nanostructures. Here we report the simple fabrication of a template based on anodic ¿aluminium oxide, having a well-defined, ordered, tunable, homogeneous 3D nanotubular network in the sub 100-nm range. The 3D templates are then employed to achieve 3D, ordered nanowire networks in ¿Bi2Te3 and polystyrene. Finally, we demonstrate the photonic crystal behaviour of both the template and the polystyrene 3D nanostructure. Our approach may establish the foundations for future high-throughput, cheap, photonic materials and devices made of simple commodity plastics, metals and semiconductors.We would like to acknowledge financial support from ERC 2008 Starting Grant ‘Nano-TEC’ number 240497.Peer Reviewe

Aerodynamic shape optimization of a 3D wing via volumetric B-Splines

This paper shows a gradient-based aerodynamic shape optimization of a threedimensional wing using volumetric B-Splines. The wing is enclosed in a volumetric parallelepiped, commonly referred as control box, which can be seen as a rubber box that deforms the enclosed space. The deformation of the wing is provided by the manipulation of the control points, where the gradients are calculated using the continuous adjoint solution. This technique can be applied to arbitrary three dimensional complex designs and provides some advantages over other traditional geometry parameterization methods, such as deformation locality and the ability to handle some geometric constraints

Cayley digraphs of finite abelian groups and monomial ideals

In the study of double-loop computer networks, the diagrams known as L-shapes arise as a graphical representation of an optimal routing for every graph’s node. The description of these diagrams provides an efficient method for computing the diameter and the average minimum distance of the corresponding graphs. We extend these diagrams to multiloop computer networks. For each Cayley digraph with a finite abelian group as vertex set, we define a monomial ideal and consider its representations via its minimal system of generators or its irredundant irreducible decomposition. From this last piece of information, we can compute the graph’s diameter and average minimum distance. That monomial ideal is the initial ideal of a certain lattice with respect to a graded monomial ordering. This result permits the use of Gr¨obner bases for computing the ideal and finding an optimal routing. Finally, we present a family of Cayley digraphs parametrized by their diameter d, all of them associated to irreducible monomial ideals

Silicon‐Germanium (SiGe) Nanostructures for Thermoelectric Devices: Recent Advances and New Approaches to High Thermoelectric Efficiency

Silicon and germanium present distinct and interesting transport properties. However, composites made of silicon‐germanium (SiGe) have resulted in a breakthrough in terms of their transport properties. Currently, these alloys are used in different applications, such as microelectronic devices and integrated circuits, photovoltaic cells, and thermoelectric applications. With respect to thermoelectricity, in the last decades, Si0.8Ge0.2 has attracted significant attention as an energy harvesting material, for powering space applications and other industrial applications. This chapter focuses on the recent advances and new approaches in silicon‐germanium (Si1−xGex) nanostructures for thermoelectric devices with high thermoelectric efficiency obtained through magnetron sputtering

Seleniuro de Plata: un candidato a la alta eficiencia termoeléctrica

Ponencia presentada en las IV Jornadas de Jóvenes Investigadores, celebradas en Madrid el 9 de julio de 2015.El actual interés en los materiales termoeléctricos se centra en su capacidad de transformar una diferencia de temperatura en una diferencia de Voltaje (efecto Seebeck). Igualmente a la creación de una diferencia de temperatura debida a un voltaje eléctrico (efecto Peltier), siendo posible utilizarlos como fuentes y sumideros de calor en aplicaciones industriales como un medio alternativo de refrigeración y enfriamiento. Entre las principales ventajas de los dispositivos termoeléctricos sobre los demás sistemas de refrigeración ¿ sistemas de compresión ¿ se encuentra una mayor fiabilidad en el tiempo de uso al no contar con partes móviles, la no utilización de gases de efecto invernadero y la ausencia de vibración debido a que son dispositivos de estado sólido con un tamaño reducido llegando a ser muy eficientes en aplicaciones locales.Peer Reviewe

Advances in Scanning Thermal Microscopy Measurements for Thin Films

One of the main challenges nowadays concerning nanostructured materials is the understanding of the heat transfer mechanisms, which are of the utmost relevance for many specific applications. There are different methods to characterize thermal conductivity at the nanoscale and in films, but in most cases, metrology, good resolution, fast time acquisition, and sample preparation are the issues. In this chapter, we will discuss one of the most fascinating techniques used for thermal characterization, the scanning thermal microscopy (SThM), which can provide simultaneously topographic and thermal information of the samples under study with nanometer resolution and with virtually no sample preparation needed. This method is based on using a nanothermometer, which can also be used as heater element, integrated into an atomic force microscope (AFM) cantilever. The chapter will start with a historical introduction of the technique, followed by the different kinds of probes and operation modes that can be used. Then, some of the equations and heating models used to extract the thermal conductivity from these measurements will be briefly discussed. Finally, different examples of actual measurements performed on films will be shown. Most of these results deal with thermoelectric thin films, where the thermal conductivity characterization is one of the most important parameters to optimize their performance for real applications