Uso de conductores iónicos de tipo óxido para aplicaciones energéticas. Introducción a las pilas de combustible y las membranas de separación de gases.

Los conductores iónicos, y los conductores mixtos de iones y electrones tienen el potencial de servir como membranas en procesos relevantes en tecnologías avanzadas de generación de energía limpia y respetuosa con el medio ambiente. Las pilas de combustible conductoras de ión óxido (solid oxide fuel cells, del inglés SOFCs) o conductoras de protones (proton conducting SOFCS, PC-SOFCs) son algunos ejemplos de generación de energía más limpia en comparación con la tecnología actual, basada en la quema de combustibles fósiles. Los conductores mixtos de protones y electrones se pueden utilizar como membranas de separación de gases a elevada temperatura para la purificación de ese gas, y éstas se pueden integrar en reactores de membrana catalítica o bien implementarse en tecnologías de captura y almacenamiento de CO2Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

¿Puede ser conveniente ventilar a todos nuestros pacientes con cánula orofaríngea?

Treball Final de Grau en Medicina. Codi: MD1158. Curs acadèmic: 2020/2021Antecedentes. El manejo de la vía aérea (VA) es una habilidad fundamental en Medicina. La ventilación con mascarilla facial (VMF) es el inicio de toda asistencia respiratoria. En caso de dificultad, se puede recurrir al empleo de dispositivos que facilitan este procedimiento, como la cánula orofaríngea. Nuestro estudio plantea la pregunta ¿por qué no usar este instrumento de manera rutinaria mejorando y facilitando la ventilación de todos los pacientes en general, incluidos los a priori "fáciles" de ventilar? Objetivo. El objetivo principal de nuestro estudio es determinar si el uso de la cánula orofaríngea durante la VMF supone un beneficio para los pacientes sin criterios de ventilación dificultosa, al aumentar el volumen corriente (VC). Como objetivos secundarios, analizamos si existieron o no diferencias en cuanto a la saturación de oxígeno, la facilidad de la ventilación para el anestesista y si hubo alguna complicación. Material y métodos. Se realizó un ensayo clínico aleatorizado controlado que consta de 100 pacientes separados en dos grupos. Las variables recopiladas se dividieron en aquellas previas a la inducción (recogidas en la consulta preanestésica) y las que se valoraron tras la inducción. En ambos grupos, tanto en el de control, como en el de intervención, se evaluó cada parámetro de la misma forma. Todos los datos se analizaron utilizando el programa estadístico IBM SPSS statistics 27. Primero se realizó un estudio descriptivo de las variables y posteriormente un análisis inferencial con el empleo del test t de Student para variables cuantitativas que cumplian la normalidad. En caso de que no la cumplieran, se empleó su alternativa no paramétrica, la prueba de U-Mann Whitney. El test de Chicuadrado se usó para variables categóricas. Resultados. El análisis estadístico mostró que el VC aumentó de 247,5 (141,4) a 428,3 (181,5), lo que corresponde a un incremento del 77,02% de los valores iniciales (p <0,001), en el grupo con cánula de Guedel. En el grupo control también se observó un aumento del VC en un 71,82%. Sin embargo, las diferencias del incremento de VC entre los dos grupos no resultaron significativas. También se observó una discreta mejoría de la saturación de oxígeno (SpO2), pasando de 98,5% a 98,9% tras colocar la cánula. Sin embargo, en el grupo sin cánula mejoró un poco más. No hubo imposibilidad de ventilación y solo hubo un caso de una pequeña lesión labial al colocar la cánula. Como limitación fundamental, destacar la imposibilidad de reunir la muestra de pacientes planificada debido a la situación de pandemia por COVID-19, por lo que se generaron datos de 80 pacientes aleatoriamente, de forma artificial, mediante un programa estadístico. Conclusiones. Nuestros resultados indican que el empleo de cánula orofaríngea puede facilitar la ventilación con mascarilla facial al aumentar el VC. En el resto de las variables no se observaron diferencias estadísticamente significativas.Background: Airway management is a fundamental skill in Medicine. Face mask ventilation is the beginning of all respiratory support. In case of difficulty, you can try to use some devices that facilitate this procedure, such as the oropharyngeal cannula. Our study raises the question, why not use this instrument routinely, improving and facilitating the ventilation of all patients in general, including those a priori "easy" to ventilate? Objectives: The main objective of our study is to determine if the use of the oropharyngeal cannula during ventilation with a face mask, represents a benefit for patients without difficult ventilation criteria, by increasing the tidal volume (TV). As secondary objectives, we analyzed whether differences appeared in terms of oxygen saturation, ease of ventilation for the anesthetist, and whether there were any complications. Design and methods: This is a randomized controlled clinical trial consisting of 100 patients separated into two groups. The variables were divided into two groups: those collected before the induction (in the preanesthetic consultation) and those that were assessed after induction. In both groups, the control group and the intervention one, each parameter will be evaluated in the same way. All data will be analyzed using the statistical program IBM SPSS statistics 27. First, a descriptive study of the variables will be carried out and later an inferential analysis. In this part, the Student's t test will be used to compare quantitative variables with a normal distribution. If the variables do not meet the normality, their non-parametric alternative, the U-Mann Whitney test, will be used. The Chi-square test will be used for categorical variables. Results: The statistical analysis showed that the TV increased from 247.5 (141.4) to 428.3 (181.5), which suppose an increase of 77.02% from the initial values (p <0.001), in the Guedel cannula group. In the control group, this increase in TV was also observed in 71.82%. However, this volume increase was not significant in either group. A slight improvement in oxygen saturation was also observed, going from 98.5% to 98.9% after placing the cannula. However, in the group without cannula it improved a little more. We didn´t find any impossibility of ventilation and only one case of a small lip lesion when placing the cannula was registered. As a main limitation, we want to remark the impossibility of gathering the planned sample of patients due to the COVID-19 pandemic situation. Because of this, data from 80 patients were generated randomly, artificially, using a statistical program. Conclusions. Our results indicate that the use of an oropharyngeal cannula facilitates ventilation with a face mask by increasing the TV. No statistically significant differences were observed in the other variables

Estudio de alternativas de instalación de un parque eólico marino en función de la batimetría y la distancia a la costa en Galícia y Cádiz

[ES] En los últimos años, la industria eólica marina se ha posicionado a la cabeza del desarrollo de las energías renovables. Europa se ha situado a la vanguardia con la conexión de un gran número de instalaciones en el ámbito geográfico de los mares del Norte y de Irlanda. Ello es debido a la existencia de un recurso eólico óptimo en áreas oceánicas con una batimetría excepcionalmente reducida, lo cual minimiza los costes y da lugar a una gran rentabilidad. El presente Trabajo persigue concluir si es viable construir un parque eólico marino en España, comparable a aquellos que están encabezando el desarrollo de la industria en otros países europeos. Para lograrlo, se ha analizado la costa española para estudiar ubicaciones similares al mar del Norte en términos de batimetría y distancia a costa. A continuación, se ha planteado el parque en distintas ubicaciones alternativas en la costa de Galicia y de Cádiz. En ambas ubicaciones se ha realizado un estudio de viabilidad económica.[EN] During latest years, the offshore wind industry has risen to the top of the development of renewable energies. Europe has achieved a leading role with the connexion of a large number of wind farms along the North Sea and the Irish Sea. This is due to the existence of an optimal wind resource in oceanic areas with an extraordinarily reduced bathymetry, which reduces costs and leads to a great cost efectiveness. The following Project pursues the aim of concluding if it is viable to build an offshore wind farm in Spain, comparable to those which are leading the development of the industry in other European countries. Because of that, Spanish shore has been analysed with the objective of studying locations similar to North Sea regarding bathymetry and distance to shore. In addition, the farm has been planned in different alternative places of the shore of Galicia and Cádiz. An economical viability study has been developed for both locations.[CA] EŶ els últiŵs aŶLJs, la iŶdústƌia ežliĐa ŵaƌiŶa s’ha posiĐioŶat al ĐapdavaŶt del deseŶvolupaŵeŶt de les eŶeƌgies ƌeŶovaďles. Euƌopa s’ha situat a l’avaŶtguaƌda aŵď la ĐoŶŶedžiſ d’uŶ gƌaŶ Ŷúŵeƌo d’iŶstal·laĐioŶs eŶ l’ăŵďit geogƌăfiĐ dels ŵaƌs del Noƌd i d’IƌlaŶda. Aidžž es deu a l’edžistğŶĐia d’uŶ ƌeĐuƌs ežliĐ žptiŵ eŶ ăƌees oĐeăŶiƋues aŵď uŶa ďatiŵetƌia edžĐepĐioŶalŵeŶt reduïda, cosa que minimitza la despesa i dóna lloc a una gran rendibilitat. El present Treball busca concloure si és viable construir un parc eòlic marí a Espanya, comparable a aquells que estan encapçalant el desenvolupament de la indústria a altres països europeus. Per a aconseguir-ho, s’ha aŶalitzat la Đosta espaŶLJola peƌ tal d’estudiaƌ uďiĐaĐioŶs siŵilaƌs al mar del Nord en termes de batiŵetƌia i distăŶĐia a Đosta. Tot seguit s’ha plaŶtejat el paƌĐ a difeƌeŶts uďiĐaĐioŶs alteƌŶatives a la Đosta de GalíĐia i Cadis. EŶ aŵďdues uďiĐaĐioŶs s’ha dut a terme un estudi de viabilitat econòmica.Magrasó Santa, C. (2019). Estudio de alternativas de instalación de un parque eólico marino en función de la batimetría y la distancia a la costa en Galícia y Cádiz. http://hdl.handle.net/10251/126482TFG

Optimisation of growth parameters to obtain epitaxial Y-doped BaZrO3 proton conducting thin films

We hereby report developments on the fabrication and characterization of epitaxial thin films of proton conducting Y-doped BaZrO (BZY) by pulsed laser deposition (PLD) on different single crystal substrates (MgO, GdScO, SrTiO, NdGaO, LaAlO and sapphire) using Ni-free and 1% Ni-containing targets. Pure, high crystal quality epitaxial films of BZY are obtained on MgO and on perovskite-type substrates, despite the large lattice mismatch. The deposition conditions influence the morphology, cell parameters and chemical composition of the film, the oxygen partial pressure during film growth being the most determining. Film characterization was carried out using X-ray diffraction, transmission electron and atomic force microscopies, wavelength dispersive X-ray spectroscopy and angle-resolved X-ray photoelectron spectroscopy. All films show a slight tetragonal distortion that is not directly related to the substrate-induced strain. The proton conductivity of the films depends on deposition conditions and film thickness, and for the optimised conditions its total conductivity is slightly higher than the bulk conductivity of the target material (3 mS/cm at 600 °C, in wet 5% H/Ar). The conductivities are, however, more than one order of magnitude lower than the highest reported in literature and possible reasoning is elucidated in terms of local and extended defects in the films

Low-temperature solid-oxide fuel cells based on proton-conducting electrolytes

The need for reducing the operating temperature of solid-oxide fuel cells (SOFCs) imposed by cost reduction has pushed significant progress in fundamental understanding of the individual components, as well as materials innovation and device engineering. Proton-conducting oxides have emerged as potential alternative electrolyte materials to oxygen-ion conducting oxides for operation at low and intermediate temperatures. This article describes major recent developments in electrolytes, electrodes, and complete fuel cell performance for SOFCs based on proton-conducting electrolytes. Although the performance of such fuel cells is still relatively modest, significant improvements in the power density output have been made during the last couple of years, and this trend is expected to continu

Effect of tri- and tetravalent metal doping on the electrochemical properties of lanthanum tungstate proton conductors

Metal doping on lanthanum tungstates at W2 site was confirmed by TOF-NPD. TGA and EIS demonstrated proton conductivity.</p

Lanthanum tungstate membranes for H-2 extraction and CO2 utilization: Fabrication strategies based on sequential tape casting and plasma-spray physical vapor deposition

[EN] In the context of energy conversion efficiency and decreasing greenhouse gas emissions from power generation and energy-intensive industries, membrane technologies for H-2 extraction and CO2 capture and utilization become pronouncedly important. Mixed protonic-electronic conducting ceramic membranes are hence attractive for the pre-combustion integrated gasification combined cycle, specifically in the water gas shift and H-2 separation process, and also for designing catalytic membrane reactors. This work presents the fabrication, microstructure and functional properties of Lanthanum tungstates (La28-xW4+xO54+delta, LaWO) asymmetric membranes supported on porous ceramic and porous metallic substrates fabricated by means of the sequential tape casting route and plasma spray-physical vapor deposition (PS-PVD). Pure LaWO and W site substituted LaWO were employed as membrane materials due to the promising combination of properties: appreciable mixed protonic-electronic conductivity at intermediate temperatures and reducing atmospheres, good sinterability and noticeable chemical stability under harsh operating conditions. As substrate materials porous LaWO (non-substituted), MgO and Crofer22APU stainless steel were used to support various LaWO membrane layers. The effect of fabrication parameters and material combinations on the assemblies' microstructure, LaWO phase formation and gas tightness of the functional layers was explored along with the related fabrication challenges for shaping LaWO layers with sufficient quality for further practical application. The two different fabrication strategies used in the present work allow for preparing all-ceramic and ceramic-metallic assemblies with LaWO membrane layers with thicknesses between 25 and 60 mu m and H-2 flux of ca. 0.4 ml/min cm(2) measured at 825 degrees C in 50 vol% H-2 in He dry feed and humid Ar sweep configuration. Such a performance is an exceptional achievement for the LaWO based H-2 separation membranes and it is well comparable with the H-2 flux reported for other newly developed dual phase cer-cer and cer-met membranes.ProtOMem Project under the BMBF grant 03SF0537 is gratefully acknowledged. Furthermore, the authors thank Ralf Laufs for his assistance in operating the PS-PVD facility. Dr. A. Schwedt from the Central Facility for Electron Microscopy (Gemeinschaftslabor fur Elektronenmikroskopie GFE), RWTH Aachen University is acknowledged for performing the EBSD analysis on the PS-PVD samples.Ivanova, ME.; Deibert, W.; Marcano, D.; Escolástico Rozalén, S.; Mauer, G.; Meulenberg, WA.; Bram, M.... (2019). Lanthanum tungstate membranes for H-2 extraction and CO2 utilization: Fabrication strategies based on sequential tape casting and plasma-spray physical vapor deposition. Separation and Purification Technology. 219:100-112. https://doi.org/10.1016/j.seppur.2019.03.015S100112219A.A. Evers, The hydrogen society, More than just a vision? ISBN 978-3-937863-31-3, Hydrogeit Verlag, 16727 Oberkraemer, Germany, 2010.Deibert, W., Ivanova, M. E., Baumann, S., Guillon, O., & Meulenberg, W. A. (2017). Ion-conducting ceramic membrane reactors for high-temperature applications. Journal of Membrane Science, 543, 79-97. doi:10.1016/j.memsci.2017.08.016Arun C. 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Serra, Hydrogen separation through tailored dual phase membranes with nominal composition BaCe0.8Eu0.2O3−δ:Ce0.8Y0.2O2−δ at intermediate temperatures, Sci. Rep. 6 (2016) 34773–34787.S. Elangovan, B.G. Nair, T.A. Small, Ceramic mixed protonic-electronic conducting membranes for hydrogen separation (2007), US 7,258,820 B2, 1997.Rosensteel, W. A., Ricote, S., & Sullivan, N. P. (2016). Hydrogen permeation through dense BaCe 0.8 Y 0.2 O 3−δ – Ce 0.8 Y 0.2 O 2−δ composite-ceramic hydrogen separation membranes. International Journal of Hydrogen Energy, 41(4), 2598-2606. doi:10.1016/j.ijhydene.2015.11.053Rebollo, E., Mortalò, C., Escolástico, S., Boldrini, S., Barison, S., Serra, J. M., & Fabrizio, M. (2015). Exceptional hydrogen permeation of all-ceramic composite robust membranes based on BaCe0.65Zr0.20Y0.15O3−δ and Y- or Gd-doped ceria. Energy & Environmental Science, 8(12), 3675-3686. doi:10.1039/c5ee01793aMontaleone, D., Mercadelli, E., Escolástico, S., Gondolini, A., Serra, J. M., & Sanson, A. (2018). All-ceramic asymmetric membranes with superior hydrogen permeation. Journal of Materials Chemistry A, 6(32), 15718-15727. doi:10.1039/c8ta04764bKim, H., Kim, B., Lee, J., Ahn, K., Kim, H.-R., Yoon, K. J., … Lee, J.-H. (2014). Microstructural adjustment of Ni–BaCe0.9Y0.1O3−δ cermet membrane for improved hydrogen permeation. Ceramics International, 40(3), 4117-4126. doi:10.1016/j.ceramint.2013.08.066(Balu) Balachandran, U., Lee, T. H., Park, C. Y., Emerson, J. E., Picciolo, J. J., & Dorris, S. E. (2014). Dense cermet membranes for hydrogen separation. Separation and Purification Technology, 121, 54-59. doi:10.1016/j.seppur.2013.10.001Shimura, T. (2001). Proton conduction in non-perovskite-type oxides at elevated temperatures. Solid State Ionics, 143(1), 117-123. doi:10.1016/s0167-2738(01)00839-6HAUGSRUD, R. (2007). Defects and transport properties in Ln6WO12 (Ln=La, Nd, Gd, Er). 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Comparison of the local and the average crystal structure of proton conducting lanthanum tungstate and the influence of molybdenum substitution

We report on the comparison of the local and average structure reported recently for proton conducting lanthanum tungstate, of general formula La28−xW4+xO54+δv2−δ, and the impact of molybdenum-substitution on the crystal structure of the material. Partial replacement of W with 10 and 30 mol% Mo is investigated here, i.e. La27(W1−xMox)5O55.5 for x = 0.1 and 0.3. This study addresses the interpretation and the description of a disordered cation and anion sublattice in this material, which enables the understanding of the fundamental properties related to hydration, transport properties and degradation in lanthanum tungstate. The report shows that Mo-substituted lanthanum tungstate is a promising material as a dense oxide membrane for hydrogen separation at intermediate temperatures.Peer reviewe