http://hdl.handle.net/2117/3208 2013-05-21T16:56:57Z http://hdl.handle.net/2117/18881 Title: Effect of humidity in charge formation and transport in LDPE Authors: Aragoneses Aguado, Andrés; Tamayo, Ildaberto; Lebrato, Alexander; Cañadas Lorenzo, Juan Carlos; Diego Vives, José Antonio; Arencón Osuna, David; Belana Punseti, Juan 2013-04-18T16:39:21Z http://hdl.handle.net/2117/18165 Title: Aprendizaje colaborativo en base a problemas mediante el uso del foro electrónico Authors: Buenestado Caballero, Pablo; Minelli de Oliveira, Janaina; Moragas Gascons, Lluís; Rodríguez Pérez, Ana Carmen; Cañadas Lorenzo, Juan Carlos; Pelayo Melero, Ignacio Manuel Abstract: La incorporación de las plataformas digitales en la educación impulsa nuevas maneras de aprender. La universidad promueve la participación sincrónica y asincrónica entre sujetos que no están en el mismo lugar, ni al mismo tiempo. Una de las herramientas tecnológicas que favorece la interacción a distancia y asincrónica es el Foro Virtual, herramienta que ayuda a compartir reflexiones y búsquedas favoreciendo, al mismo tiempo, el desarrollo de habilidades sociales y la mejora de la comunicación escrita. La relación en el Foro refuerza el aprendizaje de los individuos. El objetivo de esta comunicación es presentar un método eficiente para que un estudiante aprenda en colaboración con el grupo de compañeros mediante la resolución de problemas, el análisis y la crítica interactiva usando el foro electrónico de la plataforma digital. 2013-03-11T10:26:43Z http://hdl.handle.net/2117/17685 Title: Extracurricular learning program for professional skills development in engineering schools Authors: González Díez, David; Griful Ponsati, Eulàlia; Mudarra López, Miguel; Serrano Maestre, Maria del Pilar Abstract: This paper presents an extracurricular program called INSPIRE3 that has been implemented by the ETSEIAT (Escola Tècnica Superior d'Enginyeries Industrial i Aeronàutica de Terrassa), a center belonging to the UPC-BarcelonaTech (Universitat Politècnica de Catalunya). This program is mainly addressed to facilitate cross-curricular skills and abilities development among students through collaborative-project based learning. The projection of an attractive external image of engineering degrees offered by ETSEIAT in order to increase the enrollment in such degrees is a secondary goal of this program. Under INSPIRE3, several real, challenging and multidisciplinary engineering projects are currently under development. In this paper, INSPIRE3 motivation, program management and implementation process are described and a short description of projects under development is given as well 2013-02-12T17:45:16Z http://hdl.handle.net/2117/15287 Title: Successes and challenges of a Collaborative-PBL Program in Engineering Degrees Authors: González Díez, David; Font Andreu, Jorge; Salán Ballesteros, Maria Núria; García-Almiñana, Daniel; Ortiz Marzo, José Antonio; Mudarra López, Miguel; Griful Ponsati, Eulàlia Abstract: This paper presents an extracurricular program called INSPIRE3 that has been implemented by the ETSEIAT (Escola Tècnica Superior d’Enginyeries Industrial i Aeronàutica de Terrassa), a center belonging to the UPC-BarcelonaTech (Universitat Politècnica de Catalunya). This program is mainly aimed at facilitating cross-curricular skills and developing abilities among students through collaborative-project based learning. The projection of an attractive external image of engineering degrees offered by ETSEIAT in order to increase the enrollment in such degrees is a secondary goal of this program. Under INSPIRE3, several real, challenging and multidisciplinary engineering projects are currently under development. The main feature of this program is that the subjects of the projects are proposed by the students themselves. In this paper, INSPIRE3 motivation, program management and implementation process are described and a short description of projects under development is also given. 2012-02-21T14:51:25Z http://hdl.handle.net/2117/13485 Title: Assessment of freshwater scarcity using a model based on supply and demand law Authors: Escribano Rodríguez de Robles, Beatriz; Sellarès González, Jordi; Xercavins, Josep Abstract: The main goal of this work is to provide an analysis methodology for assessment of water scarcity problems based on supply and demand. To this end, we must first determine what can be considered as supply and demand in the water scarcity problem. Although some variables involved are physical, economical or demographical, in our approach social factors are also included. This leads us to objectify water demand standards in relation to acceptable welfare levels. Within this approach, water scarcity will appear when demand reaches a higher value than supply. Two supply levels are defined based on other works. Demand is calculated within several scenarios. These scenarios represent the outcome of political or management decisions taken to reach a welfare standard. A special scenario will represent, simply, the continuation of the current state of affairs. The variables needed to calculate demand are obtained through a multilevel model where the lowest level is formed by disciplinary models and the highest level takes into account social and political factors. The methodology is applied to the countries of the gulf of Guinea. Its application to Côte d’Ivoire is described in detail and results are given for the other eight countries of the area. To summarize the results, two indexes are suggested. With this methodology, it is possible to divide the region of the gulf of Guinea in three areas of different freshwater capacity, giving new insight with regards previous studies that did not state differences between the countries of the region. 2011-10-11T13:43:39Z http://hdl.handle.net/2117/13163 Title: Study on dielectric, thermal, and mechanical properties of the ethylene vinyl acetate reinforced with ground tire rubber Authors: Mujal Rosas, Ramón María; Orrit Prat, Jordi; Ramis Juan, Xavier; Marín Genescá, Marcos; Rahhali, A. Abstract: Mass production of tires, as well as the difficult storage or elimination is a real environmental problem. Various methods for recycling tires are currently used, such as mechanical grinding, which puts vulcanized rubber, steel, and fibers apart. The rubber may be used in several industrial applications such as flooring, insulations, footwear, etc. The aim of this article focuses on finding a new application for the old used tires (GTR). Tire dust and recycled EVA thermoplastic have been mixed, and we have checked the maximum accepted values of GTR concentration that can be admitted while keeping dielectric, mechanical, and thermal properties within acceptable values, as well as initial polymer microstructure. This would allow including GTR in industrial applications of recycled EVA. The recycled tire dust which result from the industrial milling processes has been divided by sieve in three different categories according to the size of the particles (<200, 200—500, and >" xbd="654" xhg="622" ybd="1596" yhg="1560"/>500 µm). This has then been mixed with EVA in different GTR concentrations (0%, 5%, 10%, 20%, 40%, and 70%) in order to establish its conduct through electrical, mechanical, thermal, and microstructure tests, which will be held in a range of temperatures between 30°C and 120°C, and with a range of frequency between 1 × 10-2 and 3 × 106 Hz. 2011-09-06T10:29:26Z http://hdl.handle.net/2117/13153 Title: Dielectric, mechanical, and thermal characterization of high-density polyethylene composites with ground tire rubber Authors: Mujal Rosas, Ramón María; Marín Genescá, Marcos; Orrit Prat, Jordi; Rahhali, A.; Colom Fajula, Xavier Abstract: The mass manufacture of tires and the difficulty in storing or disposing them constitute a serious environmental problem. At present, various recycling methods for tires are used, such as grinding, which separates the steel and fibers from the vulcanized rubber, then using the rubber in numerous industrial applications such as pavements, insulators, footwear, etc. The aim of this article focuses on finding a new application for the ground tire rubber (GTR). This would allow including GTR in industrial applications of recycled high-density polythene (HDPE). Tire dust and HDPE thermoplastic have been mixed, and the maximum accepted values of GTR concentration that can be admitted while keeping dielectric, mechanical, and thermal properties within acceptable values, as well as initial polymer microstructure, have been checked. In addition, the suitability of the compounds for antistatic applications is studied. The recycled tire dust which results from the industrial milling processes has been divided by sieve in three different categories according to the size of the particles (<200, 200–500, and >500 mm). This has then been mixed with HDPE in different GTR concentrations (0%, 5%, 10%, 20%, 40%, 50%, and 70%) in order to establish its conduct through electrical, mechanical, thermal, and microstructure tests, which will be held in a temperature range 30–120 C, and with a frequency range 1 10 2 and 3 106 Hz. The thermal tests determined the enthalpies and fusion temperatures which allow for the observation of changes in crystalline and microstructure of the matrix, and finally, the fracture surfaces of the compound samples have been evaluated using scanning electron microscopy. 2011-09-01T11:31:55Z http://hdl.handle.net/2117/12038 Title: INDISIM-SOM, an individual-based simulator on a website for experimenting and investigating diverse dynamics of Carbon and Nitrogen in mineral soils Authors: Gras Moreu, Anna Maria; Cañadas Lorenzo, Juan Carlos; Ginovart Gisbert, Marta Abstract: INDISIM-SOM models the dynamics and evolution of C and N related to organic matter in soils by using individual-based simulations. It is an Individual-based Model that controls a group of microbial cells at each time step, using a set of time-dependent variables for each microorganism. The space is divided into square cells. In each spatial cell, the amounts of different types of organic compounds are controlled. These are identified as polymerized organic C and N, labile organic C and N, and mineral compounds such us NNH4, NNO3, CO2 and O2. The model takes into account the activity of two types of microorganisms: decomposers (heterotrophic) and nitrifiers. Metabolic pathways and sources of C and N that they can use are identified. Some state variables and parameters related to soil organic matter and microbial activity are studied. This study presents a website at which the simulator INDISIM-SOM is accessible, and explains how to carry out some virtual experiments, in order to further advance the skills associated with this individual simulation model. 2011-03-23T15:54:26Z http://hdl.handle.net/2117/11180 Title: General analysis of the three-phase asynchronous motor with spiral sheet rotor: operation, parameters and characteristic values Authors: Mujal Rosas, Ramón María; Orrit Prat, Jordi Abstract: The objectives of this article arise through the investigation of a motor with a high starting torque although with limited intensities, weak intensity variations depending on the load, controlled losses in no-load tests, and an acceptable performance in steady state and with a good response in transient periods. All these requirements would have to be obtained without the help of power electronics, in this way the motor would be more robust, longer lasting and without the need for auxiliary equipment. In this article, the operation principle, the characteristic parameters and the obtained results for the spiral sheet motor are analyzed for three speed regimes 1000, 1500 and 3000 rpm. Also, at the end of the paper the spiral sheet motor is compared with the squirrel cage rotor, the solid rotor with rings, the wound rotor with additional resistances in the rotor circuit, and the hollow diamagnetic rotor. 2011-01-24T15:22:14Z http://hdl.handle.net/2117/11148 Title: Dielectric and mechanical characterization of PVC composites with ground tire rubber Authors: Orrit Prat, Jordi; Mujal Rosas, Ramón María; Rahhali, A.; Marín Genescá, Marcos; Colom Fajula, Xavier; Belana Punseti, Juan Abstract: The mass manufacture of tires and the difficulty for their elimination or storage constitutes a serious environmental problem. At present, several methods for the recycling of tires are used, such as mechanical crushing, in which the steel vulcanized rubber and the fibers are separated; this rubber is being used in numerous applications like pavements, insulators, footwear, etc. This study proposes a second option for obsolete tires, demonstrating their utility as dielectrics. In order to do so, ground tire rubber (GTR) has been combined with polyvinyl chloride (PVC), to obtain a composite of a polymeric matrix reinforced with GTR. In order to determine the behavior of this composite material, the electrical and mechanical tests are presented as well as, more briefly, microstructure and thermal analyses, undertaken for the various mixtures of PVC with GTR (concentrations of 0%, 5%, 10%, 20%, 40%, 50%, and 70% GTR), and three GTR particle size categories (<200 mm, 200–500 mm, and >500 mm), in a range of temperatures that varied from 30 C to 130 C, and with frequencies from between 1 10 2 Hz and 3 106 Hz. The dielectric tests have allowed for an analysis of dielectric constant, dielectric loss factor, dielectric modulus, etc. On the other hand, the mechanical analysis has involved the Young’s modulus, tensile strength, elongation at break, and toughness. Mechanical and dielectric results point out that below 20% of GTR the material features for mechanical or electrical applications are not significantly altered. 2011-01-21T12:38:15Z http://hdl.handle.net/2117/10492 Title: Broad-band electrical conductivity of carbon nanofibre-reinforced polypropylene foams Authors: Sousa Pais Antunes, Marcelo de; Mudarra López, Miguel; Velasco Perero, José Ignacio Abstract: The influence of foaming a semi-crystalline polymer reinforced with different concentrations of carbon nanofibres (0–20 wt.%) on the formation of an electrically conductive network was studied at room temperature using an impedance analyzer over a wide interval of frequencies (from 10−2 to 106 Hz). Composites were prepared by melt-compounding using a twin-screw extruder, and later chemically foamed. Although composite materials displayed lower conductivities than expected, assuming a percolative behavior, foaming promoted a tunnel-like conduction at lower CNF concentrations than in the solids. At higher CNF concentrations, no great improvements were achieved as tunneling conduction decreased with increasing local crystallinity. Foams showed electrical conduction characteristics typical of a conductive random-distributed fibre-like system, while the behavior of the solids was closer to a system of spherical particles, related to CNF aggregation. The anisotropic cellular structure of the 20 wt.% CNF composite foamed by a physical foaming process disrupted the preferential in-plane CNF orientation attained during solid preparation, with these foams showing higher through-plane conductivity and more isotropic electrical properties than the chemically-foamed ones. It has been demonstrated that foaming PP–CNF composites resulted in the formation of a conductive network at lower CNF concentrations than in the solids, with foams showing the potential for use in conductive high-performance lightweight composite systems. 2010-12-02T15:32:28Z http://hdl.handle.net/2117/9866 Title: El programa INSPIRE3: la promoción del talento en ingeniería Authors: González Díez, David; Griful Ponsati, Eulàlia; Mudarra López, Miguel; Ortiz Marzo, José Antonio; Font Andreu, Jorge; Angulo Navarro, Emilio; Salán Ballesteros, Maria Núria; Díaz González, Carlos Gustavo Abstract: El programa INSPIRE3 es una iniciativa de la Escuela Técnica Superior de Ingenierías Industrial y Aeronáutica de Terrassa (ETSEIAT, http://www.etseiat.upc.edu) dirigida al estudiantado para el desarrollo de proyectos innovadores reales, dando respuesta a cuestiones como la motivación y/o la promoción del talento y del carácter emprendedor entre el estudiantado, así como al desarrollo de competencias transversales (gestión de proyectos y presupuestos, trabajo en equipo, etc.). Su implantación y aceptación en la comunidad académica supone nueva experiencia educativa de la ingeniería y ha favorecido cambios positivos tanto en la visibilidad de la ETSEIAT en particular como en la percepción de los estudios de Ingeniería en general. El programa se basa en el desarrollo de proyectos reales y de contenido transversal por parte de grupos de estudiantado que, durante la etapa de realización, tienen oportunidad de aplicar conocimientos y habilidades adquiridas a lo largo de la carrera, a la vez que desarrollan diversas habilidades y capacidades extra curriculares. En este trabajo se presentan los orígenes de este programa, el proceso de implementación, los procedimientos de retención del conocimiento empleados y su interrelación con las titulaciones de Ingeniería Industrial e Ingeniería Aeronáutica. También se presentan los resultados del programa, así como una relación de los proyectos desarrollados hasta el momento y las líneas de actuación contempladas para el futuro. 2010-10-20T15:00:35Z http://hdl.handle.net/2117/9768 Title: Method to distinguish between space-charge and dipolar relaxation in the TSDC spectra of polyethylene electrical insulation Authors: Orrit Prat, Jordi; Cañadas Lorenzo, Juan Carlos; Sellarès González, Jordi; Belana Punseti, Juan Abstract: Medium-voltage cross-linked polyethylene (MV-XLPE) cables have an important role in the electrical power distribution system. For this reason, the study of XLPE insulation may lead to improve cable features and lifetime. Although relaxational analysis yield a lot of information about XLPE properties, sometimes their results are difficult to interpret. To overcome this handicap, we have used a combination of thermally stimulated depolarization currents (TSDC) and isothermal depolarization currents (IDC) techniques. In order to discard spurious effects from the semiconductor interfaces, preliminary measurements have been done on specially prepared cables. TSDC have been performed using conventional poling between 140°C and 40°C. IDC measurements also have been carried out at temperatures between 90°C and 110°C in 2°C steps. The TSDC spectra are dominated by a broad peak of uncertain origin. On the other hand, IDC show a combination of power and exponential currents. Exponential currents are fitted to a KWW model. The relaxation times obtained from the model present an Arrhenius behavior with Ea = 1.32 eV and τ0 = 3.29×10-16 s. The KWW parameter obtained is β = 0.8. The calculated depolarization current given by the exponential relaxation matches the predominant peak of TSDC spectra. Therefore, we conclude that in the MV cables studied the most visible peak of the TSDC spectrum has a dipolar origin. 2010-10-18T14:15:33Z http://hdl.handle.net/2117/9459 Title: La transició del batxillerat a la universitat: reflexions des de l'ETSEIAT Authors: García-Almiñana, Daniel; Griful Ponsati, Eulàlia; Mudarra López, Miguel Abstract: En aquesta presentació es volen dur a terme un conjunt de reflexions obertes en relació a aquella transició Batxillerat-Universitat, a la vista del que l’oportunitat de l’EEES pot significar, tenint present la experiència acumulada a l’Escola Tècnica Superior d’Enginyeries Industrial i Aeronàutica de Terrassa (ETSEIAT) quant a les diferents accions preses a la seva Fase Selectiva (FS). 2010-10-06T13:29:31Z http://hdl.handle.net/2117/9063 Title: Plan de Desarrollo de las Competencias Genéricas (PDCG) para los nuevos grados de ingeniería en la ETSEIAT Authors: Fernández Alarcón, Vicenç; Rodríguez Donaire, Silvia; García-Almiñana, Daniel; Suñé Torrents, Albert; Amante García, Beatriz; Griful Ponsati, Eulàlia; Marcé Nogué, Jordi; Mudarra López, Miguel; Salán Ballesteros, Maria Núria; Simó Guzmán, Pep Abstract: Esta comunicación recoge el Plan de Coordinación de las Competencias Genéricas (PCCG) para las nuevas titulaciones de Grado que se impartirán en la Escuela Técnica Superior de Ingenierías Industrial y Aeronáutica de Terrassa de la Universitat Politècnica de Catalunya, a partir del curso 2010-2011. Este PCCG se generó inicialmente como una actividad específica del taller “Cómo diseñar actividades para el desarrollo de competencias genéricas” impartido desde el Institut de Ciències de l’Educació (ICE-UPC) en Mayo de 2009, y ha constado de cuatro fases. 2010-09-23T10:32:57Z