Optimization of the catalytic layer for alkaline fuel cells based on fumatech membranes and ionomer

Polymer electrolyte fuel cells with alkaline anion exchange membranes (AAEMs) have gained increasing attention because of the faster reaction kinetics associated with the alkaline environment compared to acidic media. While the development of anion exchange polymer membranes is increasing, the catalytic layer structure and composition of electrodes is of paramount importance to maximize fuel cell performance. In this work, we examine the preparation procedures for electrodes by catalyst-coated substrate to be used with a well-known commercial AAEM, Fumasep® FAA-3, and a commercial ionomer of the same nature (Fumion), both from Fumatech GmbH. The anion exchange procedure, the ionomer concentration in the catalytic layer and also the effect of membrane thickness, are investigated as they are very relevant parameters conditioning the cell behavior. The best power density was achieved upon ion exchange of the ionomer by submerging the electrodes in KCl (isopropyl alcohol/water solution) for at least one hour, two exchange steps, followed by treatment in KOH for 30 min. The optimum ionomer (Fumion) concentration was found to be close to 50 wt%, with a relatively narrow interval of functioning ionomer percentages. These results provide a practical guide for electrode preparation in AAEM-based fuel cell research

Oral lichen planus. An evolutive clinical and histological study of 45 patients followed up on for five years

A study is made of 45 patients clinically and histologically diagnosed of oral lichen planus, and followed up on for 5 years. The course of the disease was monitored after three months and one, two and five years. The patients were classified in terms of lesion evolution (healed, improved, stationary or worse). Two evolutive groups were established for statistical purposes: (a) favorable (healed or improved lesions) and unfavorable cases (stationary or worsened oral lesions); and (b) healed and non-healed cases. Statistical correlations were established between these evolutive groups and different clinical and histological parameters, in an attempt to identify parameters of predictive value in the course of the disease. No statistically significant results were obtained, with the exception of inflammatory infiltrate. Thus, the depth of this infiltrate was found to be greater in patients with an unfavorable evolution (p = 0.02) than in those with a favorable course. Likewise, the inflammatory infiltrate was greater in non-healed than in healed cases.Dans ce travail, nous présentons une série de 45 patients, suivis pendant 5 ans, diagnostiqués cliniquement et histologiquement de lichen plan oral. Des contrôles évolutifs réalisés au bout de 3 mois, un an, deux ans et au bout de cinq ans ont classé les patients en fonction de l’évolution qu’ils présentaient en cas qui avaient guéri de leurs lésions, qui s’étaient améliorés, qui continuaient pareil et finalement ceux qui avaient empiré. Vis-à-vis des statistiques 2 groupes évolutifs se sont faits: 1) cas favorables (les guéris et ceux qui s’étaient améliorés), cas défavorables (ceux qui ne présentaient aucun changement ou ceux qui avaient empiré de leurs lésions intraorales) et 2) cas guéris, cas non-guéris. Diverses corrélations statistiques se sont établies entre ces groupes évolutifs et une série de variables cliniques et histologiques pour trouver un paramètre ayant une valeur de prédiction dans l’évolution de la maladie. Nous n’avons trouvé aucune donnée significativement statistique si l’on excepte une infiltration inflammatoire. Ainsi, nous démontrons une plus grande profondité moyenne de celle-ci dans les cas qui présentent une évolution défavorable (p = 0.02) que dans les cas favorables. De la même façon, nous trouvons une plus grande infiltration dans les cas non-guéris que dans les guéris

«Regreso al futuro»: tras la pandemia debemos intensificar la recuperación

El 31 de diciembre de 2019, la sede de la Organización Mundial de la Salud (OMS) en China fue informada de la aparición de casos de neumonía de etiología desconocida en la ciudad de Wuhan, y el tres de enero se notificaban 44 pacientes con esta patología1. Desde entonces, el brote de la enfermedad habría afectado a nivel mundial a más de 12 millones de personas y causado cerca de 600.000 muertes. Este vertiginoso paso de brote localizado a pandemia ha obligado a los sistemas sanitarios a una rápida adaptación de sus recursos materiales y humanos, interrumpiendo la rutina de los servicios hospitalarios a nivel mundial. Los casos relacionados con COVID-19 han saturado los centros obligando a convertir las áreas quirúrgicas en una prolongación de las salas de hospitalización y atención a pacientes críticos. Los equipos quirúrgicos han sido testigos de cambios dramáticos en sus prácticas con una disminución de cirugías, siguiendo el consejo dado en marzo por las sociedades científicas de cancelar la cirugía electiva no oncológica3. Los planes de contingencia de la atención hospitalaria incluían el cese de la actividad quirúrgica inicialmente programada y, según el grado de ocupación por pacientes COVID del centro, toda la cirugía, excepto la indispensable (urgente). Una reciente publicación estimaba que el número de intervenciones canceladas debidas al COVID-19 sería de 28 millones..

Obstrucción por cuerpos extraños localizados en esófago : terapéutica endoscópica. Tres casos clínicos

Se presentan tres casos clínicos de obstrucción esofágica por cuerpos extraños en posición precardial que son extraídos por técnica endoscópica con fibroencloscopio flexible.Three clinical cases of oesophagus obstruction due to foreign bodies in precardial position are described. These-foreign bodies have been removed by endoscopical technic with flexible fiberscope

Projecte CLEAR: Collaborative Learning on ECTS Array Resolution

El Projecte CLEAR s’emmarca en el procés de desenvolupament del mòdul d’aprenentatge interactiu “Array Antennas” en el context de l’assignatura d’Antenes de l’Escola Tècnica Superior Enginyeria de Telecomunicació de Barcelona. Aquest bloc del temari suposa un crèdit ECTS sent els principals objectius en aquest procés d’adaptació: fomentar el treball progressiu de l’estudiant, el seu esperit innovador i creatiu alhora que adquireixi major capacitat de relació entre els models conceptuals explicats i les estructures reals. Per assolir aquestes fites s’ha dut a terme una experiència pilot d’aprenentatge col·laboratiu de forma que es cobreixen els punts esmentats i s’aconsegueixi que l’estudiant tingui un rol més actiu en el seu propi aprenentatge fent que aquest li resulti més atractiu. A més d’aquest pilot realitzat durant el quadrimestre de tardor 2004, s’han introduït presentacions en power point del tema d’arrays i s’ha posat a disposició de tots els alumnes video-based lectures, i una eina de simulació que els permet fer tan síntesi com anàlisi per l’estudi del comportament d’antenes i les seves agrupacions

Tool wear in the dry drilling of TÍ-6AI-4V: a SEM/EDS study

En este artículo se estudia el proceso de taladrado sin fluido de corte, de la aleación Ti6A14V, comparando dos condiciones de mecanizado, con y sin enfriamiento de herramienta y material entre taladros. El objetivo de este trabajo es analizar la influencia en el desgaste de la herramienta y en la calidad del agujero, del diferente incremento de temperatura originado por trabajar en una u otra condición. Para ello, se realizará análisis SEM/EDS y microscopía óptica de la broca e inspección visual del material.This paper is focused on dry drilling of Ti6Al4V. In absence of cutting fluid, high temperatures are reached. Two different cutting conditions are studied in order to analyse the influence of temperature. In first condition, tests with no pause between drilled holes were carried out. In second condition, tests were performed cooling the tool with air between consecutively holes. Tool wear was studied with optical microscope and SEM-EDS techniques. The quality of machined holes was estimated in terms of optical inspection. Significantly differences in tool wear evolution were observed between both cutting conditions analysed.Este trabajo ha sido financiado por la Comisión Interministerial de Ciencia y Tecnología (CICYT) proyecto DPI2001-3747, por AIRBUS España, S.L. y por la Junta de Andalucía. Los autores agrádecen al Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica de la Universidad Carlos III de Madrid su ayuda y la disponibilidad de sus equipos para la realización de los estudios de microscopía óptica y SEM/EDS.Publicad

Functional traits driving species role in the structure of terrestrial vertebrate scavenger networks

Species assemblages often have a non-random nested organization, which in vertebrate scavenger (carrion-consuming) assemblages is thought to be driven by facilitation in competitive environments. However, not all scavenger species play the same role in maintaining assemblage structure, as some species are obligate scavengers (i.e., vultures) and others are facultative, scavenging opportunistically. We used a database with 177 vertebrate scavenger species from 53 assemblages in 22 countries across five continents to identify which functional traits of scavenger species are key to maintaining the scavenging network structure. We used network analyses to relate ten traits hypothesized to affect assemblage structure with the “role” of each species in the scavenging assemblage in which it appeared. We characterized the role of a species in terms of both the proportion of monitored carcasses on which that species scavenged, or scavenging breadth (i.e., the species “normalized degree”), and the role of that species in the nested structure of the assemblage (i.e., the species “paired nested degree”), therefore identifying possible facilitative interactions among species. We found that species with high olfactory acuity, social foragers, and obligate scavengers had the widest scavenging breadth. We also found that social foragers had a large paired nested degree in scavenger assemblages, probably because their presence is easier to detect by other species to signal carcass occurrence. Our study highlights differences in the functional roles of scavenger species and can be used to identify key species for targeted conservation to maintain the ecological function of scavenger assemblages.Generalitat Valenciana SEJI/2018/024, APOSTD/2019/016, CIDEGENT/ 2020/030, ACIF/2019/056Ministerio de Educación y Cultura CI-2017-32149, FJCI-2015-25632, IJC2018-036642-I, YC-2019-027216-I, RYC-2015-19231, RYC-2017-2273, GL2012-40013-C02-01/02, CGL2015- 66966-C2-1-R, CGL2015-66966-C2-1-R2, CGL2017-89905-R, RTI2018-099609-B-C21, RTI2018-099609-B-C22Govern de les Illes Balears PD/039/201National Science Centre in Poland 2013/08/M/ NZ9/00469, 2016/22/Z/NZ8/00Slovenian Research Agency P4-0059US Department of Energy DE- EM000439USA National Science Foundation #1255913California Department of Fish & Wildlife P0880013Junta de Andalucía RNM-192

Improving detection of surface discontinuities in visual-force control systms

In this paper, a new approach to detect surface discontinuities in a visual–force control task is described. A task which consists in tracking a surface using visual–force information is shown. In this task, in order to reposition the robot tool with respect to the surface it is necessary to determine the surface discontinuities. This paper describes a new method to detect surface discontinuities employing sensorial information obtained from a force sensor, a camera and structured light. This method has proved to be more robust than previous systems even in situations where high frictions occur

RIP-MD: a tool to study residue interaction networks in protein molecular dynamics

Protein structure is not static; residues undergo conformational rearrangements and, in doing so, create, stabilize or break non-covalent interactions. Molecular dynamics (MD) is a technique used to simulate these movements with atomic resolution. However, given the data-intensive nature of the technique, gathering relevant information from MD simulations is a complex and time consuming process requiring several computational tools to perform these analyses. Among different approaches, the study of residue interaction networks (RINs) has proven to facilitate the study of protein structures. In a RIN, nodes represent amino-acid residues and the connections between them depict non-covalent interactions. Here, we describe residue interaction networks in protein molecular dynamics (RIP-MD), a visual molecular dynamics (VMD) plugin to facilitate the study of RINs using trajectories obtained from MD simulations of proteins. Our software generates RINs from MD trajectory files. The non-covalent interactions defined by RIP-MD include H-bonds, salt bridges, VdWs, cation-π, π–π, Arginine–Arginine, and Coulomb interactions. In addition, RIP-MD also computes interactions based on distances between Cαs and disulfide bridges. The results of the analysis are shown in an user friendly interface. Moreover, the user can take advantage of the VMD visualization capacities, whereby through some effortless steps, it is possible to select and visualize interactions described for a single, several or all residues in a MD trajectory. Network and descriptive table files are also generated, allowing their further study in other specialized platforms. Our method was written in python in a parallelized fashion. This characteristic allows the analysis of large systems impossible to handle otherwise. RIP-MD is available at http://www.dlab.cl/ripmd

Caracterización y principales patologías de la arenisca “Piedra Dorada” empleada en los edificios históricos de las ciudades de Úbeda y Baeza (Jaén, Sur de España)

La arenisca conocida como “Piedra Dorada” es uno de los materiales más empleados en la construcción de gran parte de los edificios históricos de la provincia de Jaén. Un ejemplo de ello se encuentra en las ciudades de Úbeda y Baeza, declaradas Patrimonio Cultural de la Humanidad por la Unesco. Se ha realizado una caracterización detallada de la roca, en sus principales variedades: “Viva”, “Franca” y “Jabaluna”. Ha sido analizado tanto material de las canteras originales como muestras de monumentos. En el presente trabajo se determinan las principales características mineralógicas, texturales y geoquímicas así como las propiedades físicas de las variedades de “Piedra Dorada”. Además se profundiza en el estudio de las principales patologías encontradas en los edificios históricos de las ciudades anteriormente citadas. A partir de los diferentes parámetros determinados se ha establecido un orden de calidad de las variedades de “Piedra Dorada”. También se han caracterizado los mecanismos de deterioro entre los que se encuentran: colonización biológica (líquenes, algas, musgos y plantas superiores), ascenso capilar, depósitos superficiales (sales y costras negras) y deterioros debidos a factores antrópicos como fugas en la red de alcantarillado, ausencia de cubiertas y bajantes, etc. Este estudio ha permitido conocer en detalle una de las piedras de construcción más importantes de Andalucía con el fin de garantizar su perdurabilidad a través de los años. The sandstone known as “Piedra Dorada”, or golden stone, is one of the most commonly used materials in the construction of many of the main historic buildings in the province of Jaén. Many examples can be found in the cities of Úbeda and Baeza, declared World Heritage Cities by UNESCO. A thorough characterization of their main varieties: “Viva”, “Franca” and “Jabaluna” has been done. Original quarry materials as well as samples of monuments have been analyzed. In this study we present a characterization of the mineralogical, textural and geochemistry features as well as the main physical properties of the varieties of “Piedra Dorada”. Furthermore, this research investigates in depth the main pathologies found in historic buildings in the cities mentioned above. We have established an order of quality of the varieties mentioned from the different parameters determined. We have also characterized the deterioration mechanisms amongst which are: biological colonization (lichens, algae, moss and higher plants), an increase in capillary action, surface deposits (salts and black crust) and anthropic factors such as leaks into the sewer network, absence of covers and downspouts, etc. This study has allowed us to know in detail one of the most important construction stones of Andalusia in order to ensure its durability for future years