Browsing by Issue Date, starting with "2023-12"
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- Chemical stability of new nafion membranes doped with bisphosphonic acids under Fenton oxidative conditionsPublication . Teixeira, Fatima; Teixeira, António P. S.; Rangel, C. M.ABSTRACT: The development of new proton exchange membranes for PEM technology in fuel cells and electrolysers with increased durability is paramount to system's lifetime and scalability. In this work, new modified Nafion membranes doped with bisphosphonic acids are proposed with increased resilience to chemical degradation by H2O2/Fe2+, mimicking ex-situ radical attack to membrane structure. Relevant properties were evaluated throughout Fenton's test using fluoride ion release and gravimetry determinations, and by ATR-FTIR spectros-copy and SEM before and after the chemical degradation. The new membranes showed a very good chemical stability after oxidative degradation under Fenton's test conditions at 80 degrees C, with more durability than Nafion 115 commercial membrane. After chemical degradation, the proton conduction of the membranes was assessed through EIS which reveals a decrease in the proton conductivity of all membranes, with the new modified membranes showing a smaller decrease of their proton conduction properties than Nafion 115 membrane. Fluoride ion release, weight loss measurements and ATR-FTIR spectros-copy data analysis suggest degradation of the side chain of the ionomer.
- Oleaginous Yeast Biorefinery: Feedstocks, Processes, Techniques, BioproductsPublication . Silva, Teresa Lopes da; Fontes, Afonso; Reis, Alberto; Silva, Carla; Gírio, FranciscoABSTRACT: The world climate crisis has triggered the search for renewable energy sources. Oleaginous yeasts are a potential renewable source of biofuels. However, the yeast-derived biofuels cost is still non-competitive with the fossil fuel prices. To improve the sustainability of yeast-derived biofuels, it is necessary to valorize all yeast biomass fractions, an approach based on the biorefinery concept. This review describes the present situation of the oleaginous yeast biorefinery research, emphasizing the feedstock, processes and techniques involved in this concept, as well as on potential bioproducts that can be obtained from oleaginous yeast biomass.
- Design for Circular Economy in a Strong Sustainability ParadigmPublication . Sousa Rocha, Cristina; Antunes, Paula; Partidário, Paulo JorgeABSTRACT: Given the strategic role of design when addressing societal changes and its prominence in the circular economy (CE) discourse and practice during the past decade, a plethora of tools and methods is nowadays available to support organizations in the transition from a linear model of production to a circular one. The need for an intersection of CE, corporate sustainability, strategic design and strong sustainability is gaining momentum. Considering (a) the critical voices pointing out several limitations to the CE concept, (b) the call for linking CE to a strong sustainability paradigm and (c) the implementation mechanisms for an effective contribution to sustainable development, the focus of this research is to address the gap in CE and circular design frameworks due to missing elements therein for its successful implementation, using a Delphi method approach. Our results strongly suggest that the current CE and circular design concepts and practices are insufficient to meet the challenge of addressing strong sustainability, and new models are needed. To conclude, a new definition of design for CE in a strong sustainability paradigm and a first approach to the main elements of the new model assisted by guiding principles are proposed.
- EU-SOLARIS: The European Research Infrastructure Consortium for CSP TechnologiesPublication . Martinez, Diego; Blanco Galvez, Julian; Zarza, Eduardo; Sánchez-Moreno, Ricardo; Bataille, Francoise; Flamant, Gilles; Georgiou, Marios; Richter, Christoph; Blanco, Manuel; Cardoso, João P.; Horta, Pedro; Canavarro, DiogoABSTRACT: After many years of fruitful collaboration in the field of research infrastructures (RIs) for concentrated solar power/solar thermal energy applications, several European countries decided to apply to the European Commission to go a step forward and create a European Research Infrastructure Consortium (ERIC), a new legal form of association which poses a number of advantages in the endeavour for a further development of this technology in Europe at all levels. This new consortium, EU-SOLARIS ERIC, is likely to be legally implemented in October 2022, after a long negotiation and evaluation process, where the support of the respective Governmental research agencies of the countries involved has been crucial. EU-SOLARIS ERIC will be a legal entity and its main goal will be the improvement of the interoperability, accessibility and quality of services provided by the existing European research infrastructures to the CSP/STE research communities and industrial stakeholders. Although the current Members of the EU-SOLARIS consortium are Germany, France, Cyprus and Spain (Statutory Seat at Plataforma Solar de Almeria, Spain), plus Portugal as an Observer, it is open to any other country willing to participate as Member or Observer.
- Tales from xenoliths: the link between the Papôa Volcanic Breccia and the Berlengas Archipelago (West Portugal): geodynamic implicationsPublication . Rosa, Ana Rita; Cachapuz, P.; Santos, Telmo M. Bento Dos; Pereira, Inês; Solá, A. Rita; Carvalho, D.; Romão, José; Valverde-Vaquero, PabloABSTRACT: The Papoa Volcanic Breccia (Peniche, West Portugal) is a Mesozoic pyroclastic deposit that includes numerous igneous and metamorphic xenoliths belonging to the Variscan basement of the Lusitanian Basin, in which this unit outcrops. These rocks correspond mostly to syenogranites and diatexites affected by intense pyrometamorphism and, despite their strong secondary alteration by weathering, they still preserve several original petrographic features that are traceable to the lithologies that comprise the Berlengas Archipelago, located 15 km offshore the Peniche coast. New geochemical and mineral chemistry data now indicate a genetic relationship between these basement xenoliths and the Late Devonian migmatites outcropping in the Farilhoes Anatectic Complex. Such evidence strongly suggests the physical continuity of these high-grade metamorphic terrains at least to the Peniche region, thus constraining the nature and composition of the crustal block beneath the sedimentary sequences of the Lusitanian Basin in the studied location. In addition, in situ LA-ICP-MS U-Pb dating of rutile formed during the pyrometamorphic event endured by the xenoliths provided an age of 92.3 +/- 1.4 Ma for the Papoa volcanic eruption, placing this occurrence within the third magmatic cycle related to the opening and spreading of the North Atlantic Ocean in the West Iberian Margin.
- Design for Sustainability Tools: Categories of Classification Towards Practical UsePublication . Vicente, José; Camocho, DavidABSTRACT: Since the emergence of early approaches to design for the environment (such as green design or ecodesign), several tools have been developed to support the design process in the integration of environmental, social and, more recently in a comprehensive way, sustainability and circularity criteria. The vast quantity and diversity of tools have required the creation of ways to organize and classify them to facilitate their identification, selection and use by designers, engineers, and other product development professionals, according to the needs of the design practice objectives, and the specificities of the project. This paper aims to analyze the existing knowledge regarding design for sustainability and circularity tools to identify the main categories used to classify these tools. This was done with the aim of synthesizing the most appropriate classification from the point of view of the product designer who will use the tools. To achieve this, the methodology of literature review was employed, which included scientific papers, theses, and reference books in the field. This analysis gathered a wide diversity of classification forms and organized them into 6 overarching categories. It was also possible to verify that certain forms of classification are not particularly relevant for designers when selecting a tool, as they don’t clarify the feasibility of applying the tool. It is possible to conclude that there is still a need for homogenization and consensus in academia regarding the best way to classify these tools so that the classification is scientifically sound and useful for designers.
- Xylitol Production by Debaryomyces hansenii in Extracted Olive Pomace Dilute-Acid HydrolysatePublication . Morais, Ana Rita C.; Duarte, Luís C.; Lourenço, Pedro; Torrado, Ivone; Brás, Teresa; Neves, Luísa, A.; Carvalheiro, FlorbelaABSTRACT: The extracted olive pomace (EOP) is an industrial lignocellulosic by-product of olive pomace oil extraction, currently mainly used for energy production through combustion. In this work, the hemicellulosic fraction of EOP was selectively hydrolyzed by diluted acid hydrolysis to obtain pentose-rich hydrolysates that can potentially be upgraded by Debaryomyces hansenii, targeting xylitol production. The monosaccharides and degradation by-products released along the pre-treatment were quantified and several detoxification methods for the removal of potentially toxic compounds were evaluated, including pH adjustment to 5.5, the use of anion-exchange resins, adsorption into activated charcoal, concentration by evaporation, and membrane techniques, i.e., nanofiltration. The latter approach was shown to be the best method allowing the full removal of furfural, 41% of 5-hydroxymethylfurfural, 54% of acetic acid, and 67% of the phenolic compounds present in the hydrolysate. The effects of the supplementation of both non-detoxified and detoxified hydrolysates were also assessed. The non-detoxified hydrolysate, under aerobic conditions, supported the yeast growth and xylitol production at low levels. Supplementation with the low-cost corn steep liquor of the nanofiltration detoxified hydrolysate showed a higher xylitol yield (0.57 g/g) compared to the non-detoxified hydrolysate. The highest xylitol productivity was found in hydrolysate detoxified with anionic resins (0.30 g/L-h), which was 80% higher than in the non-detoxified culture medium. Overall, the results showed that EOP dilute acid hydrolysates can efficiently be used for xylitol production by D. hansenii if detoxification, and supplementation, even with low-cost supplements, are performed.