Decorative PVD coatings as an enviromentally clean alternative to chrome plating

The objective of this work is to conduct applied research and development to demonstrate yhat metal or ceramic coatings deposited by Physical Vapor Deposition (PVD)are equivalent or superior in peformance and are a cost-effective alternative to chrome plating in decorative applications. Chromium plating is comercially used to produce wear-resistant and decorative coatings, but the plating bath contains hexavalent chromium, which has adverse health and environmental effects. The present study describes and compares the mechanical and tribological properties of TiN,AlTiN, ZrCN coatings deposited by CAPVD (cathodic arc plasma pgysical vapor deposition), on nickel plated aluminium substrates. The properties of the above mentioned PVD coatings have been compared with the properties of conventional chromium plating.Peer Reviewe

Disentangling epitaxial growth mechanisms of solution derived functional oxide thin films

This study investigates the mechanisms of epitaxial development and functional properties of oxide thin films (Ce0.9Zr0.1O2−y, LaNiO3, and Ba0.8Sr0.2TiO3) grown on single crystal substrates (Y2O3:ZrO2, LaAlO3, and SrTiO3) by the chemical solution deposition approach. Rapid thermal annealing furnaces are very powerful tools in this study providing valuable information of the early stages of nucleation, the kinetics of epitaxial film growth, and the coarsening of nanocrystalline phases. Advanced transmission electron microscopies, X-ray diffraction, and atomic force microscopy are employed to investigate the film microstructure and morphology, microstrain relaxation, and epitaxial crystallization. This study demonstrates that the isothermal evolution toward epitaxial film growth follows a self-limited process driven by atomic diffusion, and surface and interface energy minimization. All investigated oxides experience a transformation from the polycrystalline to the epitaxial phase. This study unequivocally evidences that the film thickness highly influences the epitaxial crystallization rate due to the competition between heterogeneous and homogeneous nucleation barriers and the fast coarsening of polycrystalline grains as compared to epitaxial growth. The investigated films possess good functional properties, and this study successfully confirms an improvement at long annealing times that can be correlated with grain boundary healing processes. Thick epitaxial films can be crystallized by growing sequential individual epitaxial layers.We acknowledge financial support from Spanish Ministry of Economy and Competitiveness through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0496), CONSOLIDER Excellence Network (MAT2015-68994-REDC), COACHSUPENERGY project (MAT2014-56063-C2-1-R, co-financed by the European Regional Development Fund), and the projects MAT2011-28874-C02-01, ENE2014-56109-C3-3-R and Consolider Nanoselect (CSD2007-00041), and from the Catalan Government (2014-SGR-753 and Xarmae). AQ and MdlM are also grateful for JAE-Predoc fellowship from CSIC (E-08-2012-1321248 and E-08-2013-1028356, co-financed by the European Social Fund).Peer Reviewe

Qualidade de vida, felicidade e satisfação com a vida em anciãos com 75 anos ou mais, atendidos num programa de atenção domiciliária

This case study identifies the elements that compose the Quality of Life (QofL) of individuals who were 75 years old or older and receive care at home. The studys sample was composed of individuals 75 years or older cared for by a home health care service in the primary health care unit in Vilafranca del Penedès, Spain (n=26). The variables included: a) socio-demographic data; b) concept of QofL; c) perception of QofL; d) reasons for their perception; d) satisfaction with life and related aspects; and f) feeling of happiness. Face to face interviews were conducted. A total of 76.9% of the individuals reported a good perception of QofL and the main reasons related to it were: health, family and social relationships, and the ability to adapt. Role Theory and Disengagement Theory explain the adaptation process of these individuals at this point in life.Se objetivó detectar los elementos que participan en la Calidad de Vida (CV) de las personas mayores de 75 años que reciben cuidados domiciliarios. El diseño fue de un estudio de caso. La muestra del estudio la configuraron las personas con 75 años o más, atendidos por el servicio de Atención Domiciliaria del Área Básica de Vilafranca del Penedès (n=26). Las variables fueron: a) datos socio demográficos, b) concepto de CV; c) percepción de CV, d) motivos; e) satisfacción con la vida y aspectos relacionados; f) sentimiento de felicidad. Se aplicó la técnica de la entrevista cara a cara. El 76,9% presentó una buena percepción de CV y los principales elementos relacionados fueron la salud, las relaciones familiares y sociales y la adaptación. La teoría de los roles y la teoría de la desvinculación explican el proceso de adaptación de estos individuos en esa etapa de la vida.Objetivou-se detectar os elementos que participam da qualidade de vida (QV) das pessoas com 75 anos, ou mais que recebem cuidados domiciliários. O desenho foi de estudo de caso. A amostra do estudo foi configurada por pessoas com 75 anos, ou mais, atendidas pelo serviço de Atendimento Domiciliário da Área Básica de Vilafranca del Penedès (n=26). As variáveis foram: a) dados sociodemográficos, b) conceito de QV, c) percepção de QV, d) motivos, e) satisfação com a vida e aspectos relacionados e f) sentimento de felicidade. Aplicou-se a técnica da entrevista frente a frente. Do total, 76,9% apresentou boa percepção de QV e os principais elementos relacionados foram: saúde, relações familiares e sociais e adaptação. A teoria dos papéis e a teoria da desvinculação explicam o processo de adaptação desses indivíduos, nessa etapa da vida

Cobalt free metallic binders for HVOF thermal sprayed wear resistant coatings

Thermal sprayed HVOF WC-based cermet coatings containing various metallic binders have been used in several different applications in industries that require abrasive sliding wear resistance, such as hydraulic pistons, shafts or bearings. The potential dangerousness and cost increase off cobalt-based metallic binders, underlining the challenge in reducing reliance on this metal as metallic binder in wear resistant coatings. The present work aims to study the feasibility of WC-NiMoCrFeCo, WC-CrC-Ni and WC-FeCrAl coatings, in contrast to conventional WCCoCr, by evaluating their microstructure, mechanical, tribological and corrosion resistance properties. Commercially feedstock powders were sprayed onto steel plates using a kerosene-fuelled HVOF WokaJet 400 gun. The WC-CoCr coating shows a slightly highest hardness than WC-NiMoCrFeCo and WC-FeCrAl coatings, showing a slight trend towards an increase in the wear rate as the coating hardness decreases. The WC-CrC-Ni coating is significantly the softest and least wear resistant coating, as a consequence of the presence of a high percentage of lower hardness CrC particles. Nevertheless, this coating shows similar corrosion resistance to of conventional WC-CoCr coating, while the WC-NiMoCrFeCo and WC-FeCrAl coatings show a slightly worse corrosion resistancPeer ReviewedPostprint (published version

Model-based fault diagnosis in PEM fuel cell systems

CONAPPICE 2008, Zaragoza, Spain, 24-26 September 2008.In this work, a model-based fault diagnosis methodology for PEM fuel cell systems is presented. The methodology is based on computing residuals, indicators that are obtained comparing measured inputs and outputs with analytical relationships, which are obtained by system modelling. The innovation of this methodology is based on the characterization of the relative residual fault sensitivity. To illustrate the results, a non-linear fuel cell simulator proposed in the literature is used, with modifications, to include a set of fault scenarios proposed in this work. Finally, it is presented the diagnosis results corresponding to these fault scenarios. It is remarkable that with this methodology it is possible to diagnose and isolate all the faults in the proposed set in contrast with other well known methodologies which use the binary signature matrix of analytical residuals and faults.This work was supported by the project 'Avances en el modelo y diseño de controladores para sistemas basados en pila de combustible PEM' (4800). This work has been partially financed by the Research Commission of the Generalitat of Catalunya (Grup SAC ref. 2005SGR00537) and by Spanish Ministry of Education (CICYT projects ref. DPI-2005-05415 and ref. DPI2007-62966) and with the support of the Departamento de Universidades, Investigación y Sociedad de la Información y del Consejo Nacional de Ciencia y Tecnología (CONACYT).Peer Reviewe

La competencia de liderazgo en el grado de enfermería: Un análisis factorial de componentes principales

L'aspecte competencial està cada dia més present en la societat, des dels nivells acadèmics als laborals. D'una bona base en l'adquisició de competències en depèn una bona part l'èxit professional dels graduats, per això l'anàlisi per potenciar la seva adquisició s'ha convertit en un tema d'estudi recurrent, tant en l'aspecte de les competències bàsiques/transversals, com en el de les específiques. Les darreres seran les que tindran una incidència diferent en funció del tipus d'estudi, al mateix temps que experimentaran variacions importants en funció dels reptes i projectes innovadors que les organitzacions hagin d'afrontar. Entre las primeres, una de les competències que exerceix un paper primordial, i en la que s'ha centrat l'estudi, és la capacitat de lideratge. En concret, aquest treball analitza com perceben i adquireixen la capacitat de lideratge els estudiants d'infermeria de la Universitat de Barcelona, ja que els resulta fonamental per exercir la influència en un grup i per aconseguir les metes proposades. Per això es va preparar un qüestionari amb 70 preguntes que recollien les competències transversals i específiques adquirides en el procés d'aprenentatge, així com l'actitud de l'estudiant davant del procés d'aprenentatge. La població subjecte d'estudi van ser els estudiants del grau d'infermeria de la Universitat de Barcelona durant el curs acadèmic 2012-2013; i la tècnica de mostreig seleccionada va ser el mostreig incidental. El treball aplica l'anàlisi multivariant per reduir la dimensionalitat de les variables estudiades. En concret, l'anàlisi factorial mitjançant components principals ha permès identificar els aspectes que resumeixen i agrupen les 20 variables estudiades en 4 factors: capacitació per a la professionalització, treball autònom, capacitat crítica i presa de decisions en equips. Posteriorment, a partir de les puntuacions d'aquests quatre factors i amb la inclusió de les variables edat, sexe i procedència, es va construir un model de regressió logísticomultinomial. Els resultats obtinguts indiquen que els quatre factors influeixen positivament a l'hora d'incrementar la probabilitat de passar d'una capacitat de lideratge d'un nivell nul a un nivell mig, mentre que en l'increment de la probabilitat de pas d'una capacitat de lideratge nul·la a una d'elevada només els tres darrers factors tenen influènci

Thixomixing as novel method for fabrication aluminum composite with carbon and alumina fibers

This study focuses on a novel method for dispersion and distribution of reinforcement under high intensive shear stress to produce metal composites. The polyacrylonitrile (PAN)-based short carbon fiber (Csf) and Nextel 610 alumina fiber were dispersed under high intensive shearing at mushy zone in semi-solid of A356 by a novel method. The bundles and clusters were embedded by infiltration of slurry into the clusters, thus leading to a uniform microstructure. The fibers were embedded homogenously into the aluminum around 576-580°C with around 46% of solid fraction. Other experiments at 615°C and 568°C which are contained 0% and 90% solid respectively were not successful for dispersion and infiltration of aluminum into bundles of Csf. The alumina fiber has been cracked by high shearing load. The morphologies and crystalline phase were evaluated by SEM and XRD. The adopted thixo-process effectively improved the adherence and distribution of Csf into Al that can be developed to produce various composites by thixomixing.This study focuses on a novel method for dispersion and distribution of reinforcement under high intensive shear stress to produce metal composites. The polyacrylonitrile (PAN)-based short carbon fiber (Csf) and Nextel 610 alumina fiber were dispersed under high intensive shearing at mushy zone in semi-solid of A356 by a novel method. The bundles and clusters were embedded by infiltration of slurry into the clusters, thus leading to a uniform microstructure. The fibers were embedded homogenously into the aluminum around 576-580°C with around 46% of solid fraction. Other experiments at 615°C and 568°C which are contained 0% and 90% solid respectively were not successful for dispersion and infiltration of aluminum into bundles of Csf. The alumina fiber has been cracked by high shearing load. The morphologies and crystalline phase were evaluated by SEM and XRD. The adopted thixo-process effectively improved the adherence and distribution of Csf into Al that can be developed to produce various composites by thixomixing.Peer ReviewedPostprint (author's final draft