Environmental impact of bioplastic blends

Since the enormous and growing demand of plastics is a reality, the importance of the sustainability of these products is essential to the environmental conservation, from its very origin to its degradation, going through its manufacturing process. As common plastics (petro-based polymers) are made from fuel fossils, their production actively contributes to the carbon dioxide emissions, aggravating climate change. In this scenario, biobased polymers (bioplastics) seem to be eco-friendlier alternatives that will be consolidating its place in the market. In the recent years, many research and development resources have been invested in this field. But a biobased polymer is instantly better for the environment than its petroleum based alternative? How do we compare the impact of these two? The present project centers on the Life Cycle Assessment (LCA) of the production of REX-PLA (polylactide acid modified by reactive extrusion) done in a pilot plant. Furthermore, it assesses the impact and sustainability of industrial interest blends of REX-PLA with other polymers – in particular with acrylonitrile butadiene styrene (ABS) and two biobased polyamides (bio-PAs): PA 610 and PA 1010. Once described the theoretical foundations to understand the project, the methodology involves selecting and computing different sustainability and environmental impact indicators to assess the environmental effect for the transformation processes done to the different blends. Afterwards, adding up the eco-profiles (cradle-to-gate LCA) of the materials to these results, it is possible to compare the total environmental impact of the different industrial interest blends with its origin polymer (ABS, PA 610 or PA 1010) to determine if, from an environmental point of view, it is worth the production of these blends in larger scales. In the case of REX-PLA/ABS blend, transformation processes done in the pilot plant, turn into a greater impact for the environment than ABS alone, which proves that it is essential to integrate LCA practice throughout the development of environmentally friendlier products. On the contrary, both biobased polyamides blends with REX-PLA are found to be significantly ecologically-friendlier than the respective polyamides alone. In particular, a kilogram (kg) of REX-PLA/PA 610 blend requires 32.7 % less water and 24.5 % less energy to be produced than a kg of PA 610; and a kg of REX-PLA/PA 1010 blend requires 26.9 % less water and 41.4 % less energy to be produced than a kg of PA 1010

Modelling of solid oxide electrolizer and hydrogen leak estimation

Solid Oxide Elecyrolizers (SOEC) are electrochemical devises that produce hydrogen from water using the energy of an electric power source. SOEC operate at high temperatures (around 800ºC) and have efficiencies around 53% [1]. One of the most interesting scenarios of SOEC use is the storage of energy in hydrogen form when renewable power sources do not match the load. Because of this, it is important to study the dynamic behavior of SOEC systems in order to know their ability to adapt to changing power profiles. Different works describe SOEC models in the literature, as reviewed in [2], but time dependent models are scarse [3] and very few of the models are experimentally validated. This work presents a dy-namic model of a SOEC implemented in MATLAB Simulink and its match with experimental data. One important issue in SOEC stacks is hydrogen leak, which aggravates with ageing and is mostly caused by the high operating temperatures. The analysis of the experimental data of this work suggested hydrogen leak. Based on the SOEC thermal model, a methodology to quantify the flow of hydrogen that is leaked out is proposed and applied to the experimental system.Postprint (published version

Electrophoretic deposition of MnCo2O4 coating on solid oxide cell interconnects manufactured through powder metallurgy

Developing cost-effective and durable interconnects for solid oxide cells is crucial to overcome currently existing barriers for the commercialization of this promising energy technology. A systematic microstructural and electrical characterization of MnCo2O4 spinel coatings processed by electrophoretic deposition on SUS 445 ferritic stainless steel, manufactured through powder metallurgy, is here reviewed and discussed for application in high temperature solid oxide cells stacks. The work presents a successful com- bination of the powder metallurgy processing of metallic interconnects with the electrophoretic deposition as a fast and versatile approach to coat complex interconnect shapes. Therefore, this study assesses the effect of the sintering route of coated steel on the final microstructure. Remarkable results in terms of electrical properties are here presented for EPD coated sample reduced at 1000 °C and re-oxidised at 800 °C in static air, obtaining an area specific resistance degradation rate of 1.2 mΩ cm2/kh together with an effective limitation of Cr outward diffusion despite the prolonged exposure in relevant conditions. This novel approach opens the door for a new class of complex-shaped interconnects with enhanced performance and durability and excellent scalability at a low cost

The Catalan Surveillance Network of SARS-CoV-2 in Sewage: design, implementation, and performance

Wastewater-based epidemiology has shown to be an efficient tool to track the circulation of SARS-CoV-2 in communities assisted by wastewater treatment plants (WWTPs). The challenge comes when this approach is employed to help Health authorities in their decision-making. Here, we describe the roadmap for the design and deployment of SARSAIGUA, the Catalan Surveillance Network of SARS-CoV-2 in Sewage. The network monitors, weekly or biweekly, 56 WWTPs evenly distributed across the territory and serving 6 M inhabitants (80% of the Catalan population). Each week, samples from 45 WWTPs are collected, analyzed, results reported to Health authorities, and finally published within less than 72 h in an online dashboard ( https://sarsaigua.icra.cat ). After 20 months of monitoring (July 20-March 22), the standardized viral load (gene copies/day) in all the WWTPs monitored fairly matched the cumulative number of COVID-19 cases along the successive pandemic waves, showing a good fit with the diagnosed cases in the served municipalities (Spearman Rho = 0.69). Here we describe the roadmap of the design and deployment of SARSAIGUA while providing several open-access tools for the management and visualization of the surveillance data.The authors wish to thank the staff from all the WWTPs monitored for their help and technical support during the sampling campaigns. The authors acknowledge the funding received from the ACA and the ASPCAT from the Catalan Government (Generalitat de Catalunya). ICRA authors acknowledge the funding provided by the Generalitat de Catalunya through the Consolidated Research Group grants ICRA-ENV 2017 SGR 1124 and ICRA-TiA 2017 SGR 1318. ICRA researchers also thank the funding from the CERCA program of the Catalan Government.Peer reviewe

Inclusión de los deportes náuticos en el currículo de Educación Física en el desarrollo de una Unidad Didáctica de coordinación

To help students discover new methods of practising and sport modalities is an essential task that as learners we must carry out in order to encourage a habitual sports practice. Water sports provide us with a wide range of opportunities for students to develop their motor, social and cognitive skills. The aim of this project is to achieve a development in the coordinative abilities of the student by linking physical activity in a natural environment with improved motor performance. Therefore this project presents exposes a didactical proposal intervention for Secondary Education students which basic aim consists in coordination improvement through practicing several nautical sports in the marine environment. Besides the betterment coordination, the project is trying to revert the lack of practice in this sport by not only getting to know it but fomenting its practice in a near future.Facilitar al alumno el descubrimiento de nuevos medios de práctica y modalidades deportivas es una tarea fundamental que los discentes debemos llevar a cabo con el fin de fomentar una práctica deportiva habitual. Los deportes náuticos nos brindan una gran cantidad de posibilidades para el desarrollo motor, social y cognitivo del discente. La presente propuesta pretende lograr un desarrollo de las capacidades coordinativas del alumno interrelacionando la actividad física en el medio natural con la mejora del rendimiento motor. Por ello, el presente trabajo expone una propuesta de intervención didáctica para unos alumnos de educación secundaria en el que el objetivo principal consiste en la mejora de la coordinación mediante el trabajo con distintos deportes náuticos en el medio marino. Además de la mejora de la coordinación, la presente propuesta pretende revertir la poca práctica de éste deporte dándolos a conocer y fomentando su práctica en el futuro. Debido a la especial idiosincrasia del medio de práctica, uno de los objetos de análisis del estudio es la motivación generada por el descubrimiento y práctica de las modalidades deportivas seleccionadas

Millora de la resistència a la degradació de bescanviadors de calor en plantes IRSU mitjançant recobriments de projecció térmica HVOF.

[cat] En el document final presentat com a tesi doctoral per a la obtenció del grau de doctor per a la Universitat de Barcelona s'hi inclouen els resultats tant en forma d'articles internacionals, així com en forma de memòria de resultats obtinguts durant l'investigació. El projecte en el que es va incloure aquesta investigació presentava com a objectius l'optimització de recobriments de projecció tèrmica de diferents tipus per tal de protegir les peces dels bescanviadors de calor de les incineradores de residus sòlids urbans (IRSU); així com el disseny i optimització de la seva aplicació a nivell industrial. Així doncs el document presentà una fase més experimental d'optimització i estudi en laboratori, seguida de una segona etapa d'estudis i d'implantació a escala industrial. Es varen depositar de l'ordre de uns 12 materials diferents, obtenint tant recobriments metalics com de tipus cermets (metall + ceràmic). De tots ells s'en varen seleccionar 3 sistemes els quals presentaven les característiques òptimes per a l'aplicació a gran escala. Els resultats que es troben a la tesi s'estructuren doncs amb una primera part de selecció de recobriments i optimització de condicions per a cada un d'ells. Mentre que la segona part mostra un capitol per a cada un d'els tres sistemes seleccionats. Els tres sistemes escollits corresponen a les composicions comercials de materials com són el Inconel-625 (Base Níquel), el Hastelloy C-22 (Base Níquel) y finalment l'acer inoxidable 316L (Base Ferro). Cada un d'aquests va ser depositat a través de la tecnologia de projecció tèrmica HVOF a partir de dues condicions optimitzades amb diferents gasos de combustió. Això va donar lloc a l'estudi detallat de 6 sistemes que s'anomenaren en funció de la seva composició i les seves condicions de Projecció. L'avaluació de la resistencia a la seva aplicació i caracterització estructural d'aquests sistemes a partir de tècniques com són la Microscopia Electronica d'Escombrat, la Difracció de Raig X, Espectroscopia d'energia dispersada o la Microsonda electrónica formen part de la gran quantitat de resultats obtinguts sobre el comportament d'aquests recobriments sota condicions extremes de degradació. També s'hi presenten per cada un d'ells els resultats de resistència a l'erosió, i corrosió obtinguts mitjançant assaigs tant electroquímics com de corrosió dinámica i estàtica. La compilació de tots aquests resultats i la seva relació amb les condicions de projecció així com amb l'estructura obtinguda permeten extreure conclusions sobre l'aplicació del material a escala industrial. Els resultats dels assaigs realitzats a l'interior de la incineradora són concordants amb els obtinguts mitjançant l'assaigs de corrosió i erosiócorrosió dissenyats en el Centre de Projecció Tèrmica. D'aquesta manera es pot realitzar una avaluació d'una forma accelerada de la resistència en servei dels recobriments generats. Per altra banda es comprova que els recobriments base Níquel són aquells que presenten una millora més significativa de la resistència a la degradació del bescanviador, incrementant la seva vida en servei, de mitjana, en més de 100.000 hores. Per altra banda els recobriments d'aliatges cermets presenten problemes mecànics, i els recobriments d'aliatges base Ferro, oxidació activa. Com a conclusió de caire general s'obté que la projecció tèrmica HVOF és una alternativa econòmica que aporta les millors prestacions que altres tecnologies de revestiment en la seva aplicació per plantes IRSU en tubs intercanviadors i parets d'aigua, així com en altres sectors industrials, com són plantes químiques de liquació de gasos o plantes de generació d'energia per combustió de carbó polvoritzat i biomassa.[eng] The work entitled "Optimization of Municipal Solid Waste Incinerator exchanger degradation resistance through thermal spray HVOF coatings" present hopeful results about the resistance of HVOF coatings against the erosion and corrosion degradation mechanisms that occur on the exchangers tubes on MSWI plants. Different material compositions have been studied. Nickel, Iron and Cobalt based alloys, as well as Cermets (metals+ceramics) has been used to attain protective coatings. "In situ" tests on a real MSWI plant and "laboratory" tests have been carried out during 4 years of investigations. The document summarize all the obtained results such as characterization of feedstock materials, coatings, optimization of the HVOF spray parameters, as well as a detailed study of protector corrosion and erosion behavior under different corrosion and erosion tests. Different tests such as Electrochemical corrosion, high temperature corrosion, erosion-corrosion and salt corrosion test have been carried out and studied by SEM, ESEM; EDS, XPS and XRD techniques. Different behaviors of the coatings have been correlated with their structures and the used spray parameters. Nickel based coatings, obtained by using feedstock spray powder with compositions close to Inco-625 alloy, have been shown as the most useful for the final application. The main key parameters shown as corrosion resistance responsible have been high Nickel composition and low porosity content. The best results have been attained by spraying Diam1005 powder with HVOF Hydrogen spray process and Iron alloys as 316L has been sown as a useless materials for this kind of applications. This PhD thesis conclude that the optimized High velocity oxygen fuel thermal spray coatings (HVOF) can increase more than 100000 hours the service life time of MSWI exchanger tubes. This improving has been obtained using an economic technology as Thermal Spray HVOF

Desenvolupament i optimització de nous recobriments decoratius basats en nanopartícules d’ or en matriu dielèctrica de TiO2

Aquest projecte presenta el treball d’investigació que s’ha realitzat amb l’objectiu d’obtenir, mitjançant tecnologies de polvorització catòdica o PVD (Physical Vapor Deposition), revestiments nanocompostos formats per una matriu dielèctrica i un metall noble. Aquesta combinació entre matriu ceràmica dielèctrica i partícules metàl·liques, en mides nanomètriques, pretén aconseguir la formació de revestiments actius al fenomen que s’anomena ressonància de plasmó superficial (SPR). Els revestiments de TiO2 dielèctric es caracteritzen per a ser transparents, donant en certs casos colors d’interferència que depenen fortament del espessor del revestiment i de la morfologia d’aquest. Amb l’inclusió de nanopartícules d’or i l’aparició de la ressonància de plasmó en superfície es poden adquirir colors intrínsecs del material deguts a fenòmens d’absorció en el rang de longituds d’ona del visible. Aquests fenòmens són altament dependents tant de la mida com de la forma d’aquests nanoclústers, això pot porta a controlar el color de les mostres recobertes. Aquestes excepcionals propietats òptiques obren les portes a aplicacions industrials dels revestiments, com a decoratius en joieria o acabats per aparells de tecnologia domèstica. Però aquest no és l’objectiu únic del treball sinó que també es caracteritzen i defineixen els paràmetres que dominen aquests fenòmens per tal de dominar el fenomen i trobar-hi altres aplicacions més complexes com es la possibilitat de introduir aquest tipus de materials en camps com els dels sensors, marcadors o exhaltadors de senyal. Es tracta doncs d’un treball d’enginyeria de materials amb una forta vessant científica, que es basa en la caracterització dels paràmetres claus del procés, en busca de noves aplicacions

Environmental impact of bioplastic blends

Since the enormous and growing demand of plastics is a reality, the importance of the sustainability of these products is essential to the environmental conservation, from its very origin to its degradation, going through its manufacturing process. As common plastics (petro-based polymers) are made from fuel fossils, their production actively contributes to the carbon dioxide emissions, aggravating climate change. In this scenario, biobased polymers (bioplastics) seem to be eco-friendlier alternatives that will be consolidating its place in the market. In the recent years, many research and development resources have been invested in this field. But a biobased polymer is instantly better for the environment than its petroleum based alternative? How do we compare the impact of these two? The present project centers on the Life Cycle Assessment (LCA) of the production of REX-PLA (polylactide acid modified by reactive extrusion) done in a pilot plant. Furthermore, it assesses the impact and sustainability of industrial interest blends of REX-PLA with other polymers – in particular with acrylonitrile butadiene styrene (ABS) and two biobased polyamides (bio-PAs): PA 610 and PA 1010. Once described the theoretical foundations to understand the project, the methodology involves selecting and computing different sustainability and environmental impact indicators to assess the environmental effect for the transformation processes done to the different blends. Afterwards, adding up the eco-profiles (cradle-to-gate LCA) of the materials to these results, it is possible to compare the total environmental impact of the different industrial interest blends with its origin polymer (ABS, PA 610 or PA 1010) to determine if, from an environmental point of view, it is worth the production of these blends in larger scales. In the case of REX-PLA/ABS blend, transformation processes done in the pilot plant, turn into a greater impact for the environment than ABS alone, which proves that it is essential to integrate LCA practice throughout the development of environmentally friendlier products. On the contrary, both biobased polyamides blends with REX-PLA are found to be significantly ecologically-friendlier than the respective polyamides alone. In particular, a kilogram (kg) of REX-PLA/PA 610 blend requires 32.7 % less water and 24.5 % less energy to be produced than a kg of PA 610; and a kg of REX-PLA/PA 1010 blend requires 26.9 % less water and 41.4 % less energy to be produced than a kg of PA 1010

Solid oxide fuel cells produced by atmospheric plasma spray technology: Structural and electrochemical characterization

Trabajo presentado al "International Thermal Spray Conference and Exposition" celebrado en Houston (US) del 21 al 24 de Mayo de 2012.Ceramic materials have been used in a wide range of application. One of the most innovative applications is their use to perform Solid Oxide Fuel Cells. The aim of this work is to elucidate how to obtain a complete self-assembled SOFC (supported by electrolyte) using Atmospheric Plasma Spray (APS) to spray the three different ceramic layers. One of the main problems of SOFC production is the high costs of the process that can be reduced performing the three ceramic of a SOFC by APS technology. Anode (YSZ-NiO), Cathode (LSM) and Electrolyte (YSZ) can be obtained by APS with reasonable good behavior in terms of SOFC efficient. Another problem is the three layers assembling and adhesion, the use of gradual transition layers by APS improve the adhesion and assembling of the layers. Chemical and structural characterization of the feedstock powders and obtained ceramic layers was done by Laser Scattering, XRD, SEM and Confocal microscopy and correlated with the efficiency of attained APS-SOFC components.The authors wish to thank the Generalitat de Catalunya for the financial support for this research project 2009 SGR 00390 and to project VALTEC 09‐1‐0013.Peer Reviewe