104 research outputs found

    Stress-strain response and microstructural evolution of a FeMnCAl TWIP steel during tension-compression tests

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    © 2016. The stress-strain response of a Fe-17.5Mn-0.7C-2Al TWIP steel during cyclic loading has been investigated by means of tension-compression tests within the strain limits of ±2%, ±5% and ±10%. In addition, the microstructural evolution during the ±5% cyclic test has also been studied. The difference between the forward and reverse stress for each pre-strain has been analyzed at 0.2% offset strain and at the strains in which forward and reverse curves were parallel in order to study the Bauschinger effect (BE) and permanent softening, respectively. The evolution of the BE with pre-strain for this steel is similar to other FeMnC TWIP steels, that is, increasing values of BE are obtained as the pre-strain increases. However, its absolute values are half those reported in the literature on other FeMnC steels. This diminution of the BE is related to the lower activity of mechanical twinning in FeMnCAl TWIP steels at the pre-strains herein investigated, which promotes less polarized stresses in the matrix due to the lower dislocation storage capacity.Regarding permanent softening, the evolution is similar to that of the BE and the same analysis can be applied. During reverse compression, a slight increase of twin thickness and twin spacing with respect to the first tensile stage took place. This fact might be linked to the lower flow stress observed in the permanent softening period during reverse straining.Peer ReviewedPostprint (author's final draft

    Análisis y desarrollo de competencias de empleabilidad percibidas como no necesarias por usuarios/as de orientación laboral

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    Treball Final de Màster Universitari en Psicologia del Treball, de les Organitzacions i en Recursos Humans. Codi: SBE513. Curs acadèmic: 2019/2020.The gap between the skills developed in educational settings and those required by the labour market increases as jobs change, and it is increasingly difficult to recognize certain competences that are demanded by employers, such as necessary to remain employable and or fill a vacancy in the different work areas. This makes the work of job counsellors become a continuous search for tactics/ techniques to increase the employability of the users participating in the personalized insertion routes(IPI), modulating the itinerary as you get to know the user and difficulties appear in the strategies used to increase the possibilities of job placement, difficulties that sometimes arise due to the perception that certain competences are not necessary for the position to which they apply, conditioning the behaviour of the person towards the acquisition or improvement of these. This work presents a tool and a process inserted in a personalized itinerary of insertion that tries to promote the acquisition of those competences that companies demand, creating a perception of need that encourages the user to carry out behaviours for the acquisition of these, throwing light on those skills that by their nature or lack of knowledge of their usability in the different positions in a work area are perceived as not necessary to get a job in the sector that the user wants.La brecha entre las competencias desarrolladas en los entornos educativos y las exigidas por el mercado laboral aumenta a medida que van cambiando los puestos de trabajo, y cada vez es más difícil reconocer ciertas competencias que, son reclamadas por los/as empleadores/as, son necesarias para mantenerse empleable y/o cubrir una vacante en las diferentes áreas laborales. Esto hace que el trabajo de los/as orientadores/as laborales se convierta en una búsqueda continua de tácticas para aumentar la empleabilidad de los/as usuarios/as que participan en los itinerarios personalizados de inserción (IPI), modulando el itinerario a medida que se va conociendo el/la usuario/a y van apareciendo dificultades en las estrategias empleadas para aumentar las posibilidades de inserción laboral, dificultades que en ocasiones se produce por la percepción de que ciertas competencias no son necesarias para el puesto al que postulan, condicionando el comportamiento de la persona hacia la adquisición o mejora de estas. Este trabajo presenta una herramienta y un proceso insertado en un itinerario personalizado de inserción que trata de fomentar la adquisición de aquellas competencias que reclaman las empresas, creando una percepción de necesidad que anime al/a usuario/a a realizar conductas para la adquisición de estas, arrojando luz a aquellas competencias que por su naturaleza o desconocimiento de su usabilidad en los diferentes puesto de un área laboral, se perciben como no necesarias para conseguir un empleo en el sector que desea el/la usuario/a

    Disseny d'una instal·lació d'autoconsum solar amb aerotèrmia

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    L'objectiu principal d'aquest estudi és realitzar una instal·lació fotovoltaica en un edifici al nord de Terrassa. S'estudiaran i es compliran les diferents normatives aplicables al nostre projecte, i s'analitzaran també les seves característiques pròpies com els consums i l'entorn de treball. Com a complement a la instal·lació fotovoltaica també s'ha planejat la instal·lació d'una bomba de calor aerotèrmica que redueixi les despeses en gas i aprofiti els excedents elèctrics del mòdul

    Hidrógeno verde y biogás como alternativas energéticas en España

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    En la actualidad, el problema energético es uno de los desafíos más importantes que enfrenta España. La dependencia de fuentes de energía no renovables, como el petróleo y el gas natural, ha generado una serie de consecuencias negativas que derivan tanto a nivel económico como ambiental. Esta situación se agrava debido a la vulnerabilidad de España a los precios internacionales de la energía, lo que ha llevado a oportunidades perdidas y a una creciente preocupación por la seguridad energética. En cuanto al desarrollo de las energías renovables, se han identificado distintos tipos de fuentes de energía verde, como la solar, eólica, hidroeléctrica, biomasa, geotérmica, hidrógeno y biogás. Estas fuentes renovables ofrecen una alternativa viable y sostenible a los combustibles fósiles, contribuyendo a la reducción de emisiones de gases de efecto invernadero ya la mitigación del cambio climático.Grado en Comerci

    El populismo como fuerza política en el desarrollo del Estado ecuatoriano

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    De los fenómenos socio-políticos más estudiados y discutidos entre los científicos sociales se encuentra, sin lugar a duda, el populismo, al que se ha etiquetado de muchas y muy variadas maneras, que van desde el análisis meramente descriptivo hasta la más elaborada conceptuación teórica que crea categorías e intenta universales. Será tal vez por las diferencias, abismales muchas veces, que se presentan en cada uno de los casos, que la teoría social no ha podido, hasta hoy, ponerse de acuerdo sobre los elementos, referencias y características sustanciales que conforman el fenómeno populista. Lo que sí es seguro es que antes de poder decir con fundamento cómo es el populismo debemos saber qué y cómo es posible. ¿Es un trágico y absurdo fenómeno social?; ¿se realiza mediante plan providencial o está sujeto a leyes inmanentes?; ¿es necesario de la arbitrariedad, o campo del determinismo?; A cada una de estas preguntas, y a todas ellas en conjunto, sólo podemos responder satisfactoriamente si sabemos qué es el populismo. A ello han de cooperar conjuntamente, en un esfuerzo común, historiadores y sociólogos. La presente Tesis trata de explicar al populismo como concepto general, teorías del mismo, características, el discurso, el clientelismo y la cultura política, además las características del líder carismático

    Analysis of the decrease of the apparent young's modulus of advanced high strength steels and its effect in bending simulations

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    In this paper the evolution of the Young’s Modulus (E) during unloading with plastic deformation has been studied for different Dual-Phase AHSS from DP780 to DP1400. During unloading, all the DP steels studied showed the presence of microplasticity so an Apparent Young’s Modulus (EA) has been defined. Although that in all cases EA decreased with a non-linear behavior as the plastic strain was increased, it has been observed that the final percentage of decrease seems to be related to the microstructure of DP steels. As the ferrite content increased as in the lower strength DP steels, the reduction of EA is larger, reaching a 21%. The introduction of the variation of the elastic response during unloading in the simulation of a bending operation has allowed obtaining an improvement of the accuracy in springback prediction in all the DP steels studied. For the low strength DP steels the final shape obtained by simulation is in fact the same than the real one. As the strength of steel is increased, the accuracy is less, especially in the DP 1400 steel, in which differences in bending angle higher than a 15% are still found.Postprint (published version

    Modeling and performance estimation of robotic systems using ROS: application to drone-based services

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    Smart Robots are an integral part of the 4th Industrial Revolution. Its integration as essential components in robot-based services is not straightforward. Each robot is a cyber-physical system (CPS) where a mechanical part operates under the control of a digital board(s). Modeling and simulation of such devices has specificities to be taken into account. Model-Driven Design (MDD) has proven to be a powerful System Engineering methodology able to cope with the complexity of services built as a system of CPSs (CPSoS). In this paper, a methodology is proposed to seamlessly integrate robots into a MDD framework so that the whole service can be simulated and its performance, analyzed. Although the methodology is valid for robots in general, it has been assessed on a drone-based service.This work has been partially funded by the EU and the Spanish MICINN through the ECSEL Comp4Drones project and the TEC2017-86722-C4-3-R PLATINO project respectively

    Xenopus Oocytes as a Powerful Cellular Model to Study Foreign Fully-Processed Membrane Proteins

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    The use of Xenopus oocytes in electrophysiological and biophysical research constitutes a long and successful story, providing major advances to the knowledge of the function and modulation of membrane proteins, mostly receptors, ion channels, and transporters. Earlier reports showed that these cells are capable of correctly expressing heterologous proteins after injecting the corresponding mRNA or cDNA. More recently, the Xenopus oocyte has become an outstanding host–cell model to carry out detailed studies on the function of fully-processed foreign membrane proteins after their microtransplantation to the oocyte. This review focused on the latter overall process of transplanting foreign membrane proteins to the oocyte after injecting plasma membranes or purified and reconstituted proteins. This experimental approach allows for the study of both the function of mature proteins, with their native stoichiometry and post-translational modifications, and their putative modulation by surrounding lipids, mostly when the protein is purified and reconstituted in lipid matrices of defined composition. Remarkably, this methodology enables functional microtransplantation to the oocyte of membrane receptors, ion channels, and transporters from different sources including human post-mortem tissue banks. Despite the large progress achieved over the last decades on the structure, function, and modulation of neuroreceptors and ion channels in healthy and pathological tissues, many unanswered questions remain and, most likely, Xenopus oocytes will continue to help provide valuable responses.The work in the authors’ laboratories has been supported by grants SAF2017-82977-P (AEI/FEDER, UE) and PGC2018-093505-B-I00 from MINECO and GRE17-01 from Universidad de Alicante (Spain)

    Escape Room as a Didactic Tool in Histology Teaching

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    En el marco de un proceso de aprendizaje activo, se investigó el rendimiento académico a corto y a largo plazo de los estudiantes en dos sesiones prácticas de la asignatura de Histología a las que se incorporó un escape room. También se evaluó su impacto en la motivación y la retención del conocimiento. Los estudiantes fueron clasificados en un grupo control, que siguió una metodología de enseñanza tradicional, y un grupo experimental, que participó en la actividad del escape room. Los resultados revelaron mejoras significativas en las calificaciones posteriores a la intervención en el grupo experimental. El estudio también evaluó la percepción estudiantil de la experiencia del escape room que demostró valoraciones muy satisfactorias.In the context of an active learning process, this study investigated the short-term and long-term academic performance of students in two practical sessions of the Histology course, which included an escape room activity. The impact of this approach on motivation and knowledge retention was also assessed. Students were divided into a control group, which followed a traditional teaching methodology, and an experimental group, which participated in the escape room activity. The results revealed significant improvements in post-intervention grades in the experimental group. Additionally, the study assessed students' perceptions of the escape room experience, which showed highly satisfactory evaluations.Esta investigación ha sido financiada por el Programa Redes-I3CE de Calidad, Innovación e Investigación en Docencia Universitaria de la Universidad de Alicante, de la convocatoria 2022/24 (Referencia 5850)

    La impedancia de secuencia negativa como indicador de falla en motores de inducción

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    RESUMEN: En este trabajo se presenta un algoritmo basado en la impedancia de secuencia negativa para detectar fallas entre espiras de los motores de inducción, se explica su implementación en un prototipo electrónico de diagnóstico y sus resultados se verifican experimentalmente en un motor de 3 Hp, el cual se acondicionó para realizar fallas entre espiras. Se concluye que es útil como parámetro de diagnóstico al poder detectar fallas incipientes a partir de cinco espiras en cortocircuito, mostrando ser una buena herramienta para el mantenimiento predictivo de los motores eléctricos de inducción.ABSTRACT: An algorithm to detect inter-turn faults in induction motors based on the negative sequence impedance is presented in this paper. The implementation through a digital prototype is also explained and its results are tested using a 3 Hp induction motor designed to induce inter-turn faults. It is concluded that the robustness of the algorithm can detect incipient faults from five turns, and it is a good tool for predictive maintenance of induction motors
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