3D printing of solid oxide fuel cell

Nowadays, 3D printing is booming as a processing technique, thanks to its versatility in the manufacture of complex geometries and with a quality finish, which cannot be obtained using traditional techniques and can reduce the costs of table-processing (such as, for example, surface finishing, etc.). With this technology, the aim is to bring science and society closer together, with the ultimate goal of developing new devices that are much more efficient than the current ones in order to produce clean energy. Specifically, in the field of energy and in particular in 3D printing of solid oxide fuel cells, since the fuel used is derived from hydrogen in contact with air to produce energy and water vapour. Therefore, this technology avoids the generation of greenhouse gases, such as CO2. The purpose of this final Bachelor’s project (TFG) is the combination of these two fields, focusing on the electrolyte printing of solid oxide fuel cells, with the main objective of obtaining the final material with microstructural and mechanical properties similar to those obtained by traditional techniques. Nevertheless, through this Bachelor’s project, a new research field will be implemented within the CIEFMA group (Centre for Structural Integrity and Reliability of Materials) of the Department of Materials Science and Metallurgic Engineering UPC's , with the future long term purpose of getting all the parts of the battery printed; electrolyte, cathode and anode. To carry out this study, two geometries have been chosen, tubular and hexagonal, where the proportions of the printing material, processing conditions, etc. have been modified in order to achieve materials with a relative density higher than 99% and mechanical properties similar to the theoretical values of the materials used, by means of technical characterization advances (for example: electron microscopy, nanoindentació, etc.). Subsequently, the cathode was deposited by dip-coating and adhesion was studied by means of nanometric scale scratch-out tests. A density greater than 99% has been obtained with a hardness and modulus of elasticity of the printed material comparable to the theoretical value obtained by conventional forming techniques. The cathode also has good adhesion to the electrolyte, since no cracks or other mechanisms of damage to the interface can be observed through the optical microscop

Relación empírica entre la Terapia Racional Emotivo-Conductual (TREC) de Ellis y la Terapia Cognitiva (TC) de Beck en una muestra costarricense

En este estudio se explora una posible relación empírica entre la terapia racional emotivoconductual (TREC) de Ellis y la terapia cognitiva (TC) de Beck, dos de los modelos más conspicuos en el campo de la psicoterapia cognitiva actual. Si bien este modelo utiliza el término cognitivo en forma tal que se encuentra asociado con el afecto, la fisiología y la conducta (Dobson, 1986), sostiene que las perturbaciones emocionales, en esencia, son causadas por el proceso cognitivo del individuo. En esta investigación, se trabajó con una muestra de 200 estudiantes de la Universidad de Costa Rica de diferentes áreas a quienes se les aplicaron las escalas de: Attitudes and Beliefs Inventory (ABI) [Escala de Actitudes y Creencias], y el Beck Depression Inventory, 2ª edición (BDI-II) [Inventario de Depresión de Beck], escalas que fueron adaptadas al español. El análisis estadístico de los datos confirma empíricamente la relación entre ambos modelos

Rapidly retargetable interactive translingual retrieval

This paper describes a system for rapidly retargetable interactive translingual retrieval. Basic functionality can be achieved for a new document language in a single day, and further improvements require only a relatively modest additional investment. We applied the techniques rst to search Chinese collections using English queries, and have successfully added French, German, and Italian document collections. We achieve this capability through separation of language-dependent and language-independent components and through the application of asymmetric techniques that leverage an extensive English retrieval infrastructure.

D'Ermua a Patxi López (1997-2009) : la complicitat de la premsa amb la política espanyola al País Basc

"D'Ermua a Patxi López (1997-2009): la complicitat de la premsa amb la política espanyola al País Basc" versa sobre la connivència de determinats mitjans de comunicació escrits a Madrid, principalment, amb una estratègia política d'Estat. Una estratègia instigada pels governs del Partit Popular (1996-2004) que perseguia estigmatitzar el conjunt del nacionalisme basc associant-lo al terrorisme de l'organització ETA. Es tractava d'una campanya d'intoxicació de l'opinió pública per desacreditar el govern del PNB a Vitòria i, així, fer possible l'alternança política. Tanmateix, el fracàs del tàndem PP-PSE a les eleccions basques de 2001 dóna pas al perfeccionament de l'alternança, per mitjà de l'aprovació de la Llei de Partits Polítics (2002) que possibilità la posterior il·legalització de l'esquerra abertzale, tot fent-la fora del joc parlamentari

Quality Control in Crowdsourced Object Segmentation

International audienceThis paper explores processing techniques to deal with noisy data in crowdsourced object segmentation tasks. We use the data collected with "Click'n'Cut", an online interactive segmentation tool, and we perform several experiments towards improving the segmentation results. First, we introduce different superpixel-based techniques to filter users' traces, and assess their impact on the segmentation result. Second, we present different criteria to detect and discard the traces from potential bad users, resulting in a remarkable increase in performance. Finally, we show a novel superpixel-based segmentation algorithm which does not require any prior filtering and is based on weighting each user's contribution according to his/her level of expertise

Fracture mechanics analysis of hardmetals by using artificial small-scale flaws machined at the surface through short-pulse laser ablation

Laser ablation has become an innovative treatment for cemented carbides, regarding edge rounding and surface modification, aiming to improve their tribomechanical performance. Meanwhile, the precision offered for this technique has also positioned it as an effective mean to generate micronotches used for evaluation of mechanical properties in structural materials. However, similar approach has not been attempted for hardmetals; thus, it becomes the main objective of this work. Dimple-like and elongated micronotches are introduced in one fine-grained WC-11%wtCo grade. In doing so, laser processing parameters are first optimized to attain micronotches with appropriated geometry and size, i.e. similar to critical flaws identified in broken pristine specimens. Success of the implemented approach is then validated through subsequent flexural testing, fractographic inspection and fracture mechanics analysis of the results attained on samples containing surface micronotches, as far as laser-induced residual stresses are taken into consideration. In this regard, elongated micronotches are found to exhibit lower residual stresses, and postulate themselves as the optimal option of the two micronotch types studied. The suitability of laser ablation for shaping artificial small-scale flaws opens a new route for introducing controlled defects, alike those intrinsic to processing or induced during service, key aspect for further understanding damage tolerance issues in cemented carbides.Peer ReviewedPostprint (published version

Rapid probe of the nicotine spectra by high-resolution rotational spectroscopy

Nicotine has been investigated in the gas phase and two conformational forms were characterized through their rotational spectra. Two spectroscopic techniques have been used to obtain the spectra: a new design of broadband Fourier transform microwave (FTMW) spectroscopy with an in-phase/quadrature- phase-modulation passage-acquired-coherence technique (IMPACT) and narrowband FTMW spectroscopy with coaxially oriented beam-resonator arrangement (COBRA). The rotational, centrifugal distortion and hyperfine quadrupole coupling constants of two conformers of nicotine have been determined and found to be in N-methyl trans configurations with the pyridine and pyrrolidine rings perpendicular to one another. The quadrupole hyperfine structure originated by two 14N nuclei has been completely resolved for both conformers and used for their unambiguous identification. © 2011 the Owner Societies