Browsing by Issue Date, starting with "2024-04"
Now showing 1 - 10 of 12
Results Per Page
Sort Options
- European patterns of local adaptation planning : a regional analysisPublication . Buzási, Attila; Simoes, Sofia; Salvia, Monica; Eckersley, Peter; Geneletti, Davide; Pietrapertosa, Filomena; Olazabal, Marta; Wejs, Anja; Hurtado, Sonia De Gregorio; Spyridaki, Niki-Artemis; Csete, Mária; Torres, Efrén Feliu; Rižnar, Klavdija; Heidrich, Oliver; Grafakos, Stelios; Reckien, DianaABSTRACT: While European regions face a range of different climate hazards, little is known about how these differences affect local climate adaptation planning. We present an analytical framework for evaluating local climate adaptation plans (LCAPs) and apply it to 327 cities in 28 countries across different European regions. To do this, we use statistical methods to identify regional clusters based on overall plan quality, impacts, vulnerable population groups, and sectors addressed by LCAPs. By comparing both geographic and statistical clusters, we found (1) significant spatial heterogeneity across European cities but (2) higher average plan quality scores and more consistent strategies across cities in Central and Eastern Europe. Notably, we found no regional differences regarding (a) the climate impacts and vulnerable communities identified in plans: (b) the most commonly addressed impacts, which were urban temperature and changing precipitation patterns; and (c) the residents that cities identified as most vulnerable, namely older people, women, infants, and the sick. Our study provides a spatial analysis of European LCAPs to uncover regional policy perspectives on local climate adaptation issues. Such approaches can effectively inform broader EU, national and regional strategies that aim to support local adaptation planning in a context of multi-level governance.
- From source to surface: clues from garnet-bearing Carboniferous silicic volcanic rocks, Iberian Pyrite Belt, PortugalPublication . Cravinho, André; Rosa, Diogo; Relvas, Jorge M.R.S.; Solá, A. Rita; Pereira, Inês; Paquette, J. L.; Borba, M. L.; Tassinari, Colombo C. G.; Chew, David; Drakou, Foteini; Breiter, Karel; Araújo, VítorABSTRACT: This work investigates the relationships between partial melting, melt extraction, pluton growth and silicic volcanism in garnet-bearing felsic volcanic rocks that were extruded in the Iberian Pyrite Belt, at ca. 345 Ma. The garnets are of peritectic origin, displaying textural and chemical features of disequilibrium crystallization during partial melting reactions involving biotite at high temperatures (up to 870 degrees C) in the middle-lower crust. Major element composition suggests compositional equilibrium with the entrained and pinitized peritectic cordierite, but reveals some subsequent homogenization by diffusion. Trace element maps and spot analyses of garnet show, nonetheless, significant trace element variations, reflecting biotite and Y-REE-P-rich accessory phase breakdown during partial melting reactions. Peritectic garnet and cordierite growth resulted in the preservation of Th- and Y-rich prograde suprasolidus monazite, which constrains the timing of partial melting of the metapelitic protolith at ca. 356.8 +/- 2.4 Ma. The zircon cargo further shows that a significant amount of zircon crystals from previously crystallized felsic melts were also remobilized and erupted. These were likely stored in an upper crustal pluton that grew episodically since ca. 390 Ma during voluminous melt generation periods within the middle to lower crust, which also resulted in voluminous volcanism. The geochemical trends of the felsic volcanic rocks reflect the entrainment of xenoliths of peritectic garnet, cordierite and feldspar, and as such, the garnet-bearing felsic volcanic rocks represent an erupted mixture of a lower-temperature (ca. 770 degrees C) silicic melt and autocrysts, and peritectic phases and zircon crystals from previously crystallized and stored felsic melts.
- Levelling geochemical datasets as a tool to overcome boundary features in data applied to mineral explorationPublication . Batista, Maria Joao; de Oliveira, Daniel Pipa Soares; Salgueiro, Rute; Inverno, CarlosABSTRACT: The existence of a large number of chemical analyses resulting from decades of geochemical exploration campaigns, yields huge numbers of analytical results produced with different analytical methods, sampling protocols and sampling means. Therefore, it is necessary to level these analytical results to make them comparable and thus take advantage of the potential of geochemical information from contiguous areas. In this study, a levelling technique was used on geochemical datasets of tested bands between the 1:25 000 scale maps, 293/294 and 305/306 sheets, respectively, from the Beira Baixa region where stream sediments were sampled during a project for rare earth elements exploration. These samples were analysed for lanthanum by the same analytical methods and in the same laboratory, but in different periods and the border effects were observed. These levelling techniques must be adapted to the data to be compared and in the present case the disappearance of the border effect of the analytical results of 293/294 and 305/306 topographic sheets was observed.
- Simulation, Structural, Thermal and Mechanical Properties of the FeTiTaVW High Entropy AlloyPublication . Martins, Ricardo; Gonçalves, António Pereira; Correia, J.B.; Galatanu, Andrei; Alves, E.; Tejado, Elena; Pastor, Jose Ygnacio; Dias, MartaABSTRACT: Developing new materials to be applied in extreme environments is an opportunity and a challenge for the future. High entropy alloys are new materials that seem promising approaches to work in nuclear fusion reactors. In this work, FeTaTiVW high entropy alloys were developed and characterized with Molecular Dynamic and Hybrid Molecular Dynamic Monte Carlo simulations. The simulation results show that phase separation originates a lower potential energy per atom and a high level of segregation compared to those of a uniform solid solution. Moreover, the experimental diffractogram of the milled powder shows the formation of a body-centred cubic-type structure and the presence of TiO2. In addition, the microstructure of the consolidated material evidenced three phases: W-rich, Ti-rich, and a phase with all the elements. This phase separation observed in the microstructure agrees with the Hybrid Molecular Dynamic Monte Carlo simulation. Moreover, the consolidated material's thermal conductivity and specific heat are almost constant from 25 degrees C to 1000 degrees C, and linear expansion increases with increasing temperature. On the other hand, specific heat and thermal expansion values are in between CuCrZr and W values (materials chosen for the reactor walls). The FeTaTiVW high entropy alloy evidences a ductile behaviour at 1000 degrees C. Therefore, the promising thermal properties of this system can be attributed to the multiple phases and systems with different compositions of the same elements, which is exciting for future developments.
- Biomass and microbial lipids production by Yarrowia lipolytica W29 from eucalyptus bark hydrolysatePublication . Dias, Bruna; Lopes, Marlene; Fernandes, Helena; Marques, Susana; Gírio, Francisco; Belo, IsabelABSTRACT: Using lignocellulosic biomass hydrolysate as a renewable and abundant feedstock for microbial lipids production is a sustainable and economic high-potential approach. This study investigated the potential of the oleaginous yeast Yarrowia lipolytica to produce lipids-rich biomass from eucalyptus bark hydrolysate (EBH) obtained by enzymatic hydrolysis of the biomass pretreated by steam explosion. The effect of EBH concentration (undiluted and 1:3 v/v diluted) and medium supplementation (CSL and KH2PO4) was evaluated in Erlenmeyer flasks and lab-scale stirred tank bioreactor, respectively. Additionally, the effect of volumetric oxygen transfer coefficient (kLa) and mode of operation (batch and two-stage repeated batch) was also assessed in the bioreactor. Under the best experimental conditions (undiluted EBH, 2 g center dot L-1 CSL, 1.8 g center dot L-1 (NH4)2SO4, and kLa of 66 h-1), Y. lipolytica W29 grown in batch cultures accumulated 26 % (w/w) of intracellular lipids, corresponding to 5.6 g center dot L-1 of concentration. Lipids of Y. lipolytica were highly unsaturated and mainly composed of oleic acid (48 %), followed by palmitoleic (20 %), linoleic (17 %) and palmitic acids (14 %). This composition of Y. lipolytica lipids suggests their potential use as feedstock for biodiesel (a renewable biofuel). This work demonstrated the robust features of Y. lipolytica W29 as a potential lipids production platform to implement lignocellulose-based biorefineries.
- Strategic Behavior of Competitive Local Citizen Energy Communities in Liberalized Electricity MarketsPublication . Algarvio, Hugo; Couto, António; Lopes, Fernando; Estanqueiro, AnaABSTRACT: The liberalization of energy retail markets empowered consumers with the ability to be part of new emerging entities, such as Citizen Energy Communities. With the increasing penetration of decentralized variable generation, communities have the advantage of incentive local carbon neutrality and sustainability. Local generation reduces transport grid usage and costs to consumers. Furthermore, worldwide legislation incentives energy communities by providing them discounts to other fee parts of the tariff apart from wholesale prices. This paper presents a model of strategic behavior, investment, and trading of energy communities. The model comprises the investment in local renewable generation, the design of competitive tariffs, and strategic bidding on wholesale markets. Consumers have an optimization model that selects the retail tariff that minimizes their costs with energy. These models are tested using data from Portuguese consumers and the Iberian electricity market. Results from the study indicate that inflexible consumers may reduce their costs by 29% by being part of the community. Furthermore, they have the potential to reduce their costs above 50% when using demand-response, adapting themselves to local production and wholesale prices.
- The bimodal Fii-A2-type and calc-alkaline volcanic sequence of the Aljustrel brownfield region, Iberian Pyrite Belt, SW Iberian MassifPublication . Lains Amaral, João; Solá, A. Rita; Santos, Telmo M. Bento Dos; Feitoza, L. M.; Tassinari, Colombo C. G.; Crispim, Lourenço; Chichorro, Martim; Hofmann, Mandy; Gãertner, Jessica; Linnemann, Ulf; Gonçalves, JoãoABSTRACT: The Iberian Pyrite Belt (IPB) is a late Devonian- Early Carboniferous world-class polymetallic VMS province that includes significant Cu-(Sn)-Pb-Zn-(Ag) deposits of massive sulphides and feeder zones. The Aljustrel brownfield region contains one of the highest concentrations of ore in the IPB in 6 known deposits (Gaviao, Sao Joao, Moinho, Algares, Estacao and Feitais). To delve into the petrogenesis of the Aljustrel early Carboniferous (similar to 355 Ma) felsic-dominated bimodal volcanism, new whole-rock trace elements and Sm-Nd isotopes, and U-Pb in zircon were obtained. Based on Ga/Al and Y/Nb ratios, it is shown that Aljustrel felsic magmatism has the geochemical features of A2-type melts, typical of post-collisional and back-arc settings. U-Pb in zircon for a juvenile felsic volcanic rock point to antecrysts ages spanning from 387.9 to 366.6 Ma and a maximum emplacement age of 354.3 +/- 2.6 Ma. These long-lasting melting events, present in both juvenile (epsilon Ndi = +1.79) and evolved felsic rocks (epsilon Ndi =-5.07), imply heterogeneous sources dominated by zircon-bearing igneous rocks. The Sm-Nd model ages are in accordance with previous Lu-Hf model ages in zircon, reinforcing that the isotopic variability is related to the same petrogenetic process. Subordinated Aljustrel mafic rocks, coeval with the abundant felsic volcanism, show orogenic signatures, namely Nb-Ta-Ti negative anomalies and calc-alkaline affinities, whereas Sm-Nd isotopic data (epsilon Ndi = +1.54 to +5.48) points to variable to no contamination with crustal material. These geochemical results suggest derivation from an enriched mantle source modified by subduction metasomatism. In addition, the mafic rocks did not provide zircons for geochronological analysis, with the exception of one sample, in which a Concordia age of 402.1 +/- 15.5 Ma was obtained from a single grain. The combined geochemical signatures of mafic and felsic volcanic rocks suggest asthenospheric rise, but this solely does not explain the abundance of zircon antecrysts in the felsic rocks. Therefore, a geodynamic model that includes a continuous evolution from Devonian to Carboniferous times is inferred. This more complex and broader geodynamic model for the Iberian Pyrite Belt in which successive metal remobilization occurred after successive melting events, fits the present geochemical data and is more likely to explain why the Iberian Pyrite Belt is a unique metallogenetic province.
- Potential for hydrogen production associated to water and food in off-grid communities of Southern AfricaPublication . Rodrigues, Luiz; Araujo, Luis; Gano, António; Pinto, P.J.R.; Simoes, Sofia; Brito, Paulo; Monjane, Armindo; Rangel, C. M.ABSTRACT: Solar energy is called to meet electricity demands for isolated, off-grid communities in Africa. However, solar electric energy is intermittent and can be stored, for a limited amount of time, in batteries, which are expensive and cause serious environmental impacts at the end of their lifetime. Conversion of the surplus electric energy to green hydrogen through water electrolysis and back to electricity, when needed, using electrolyser-fuel cells systems, is examined as a potential solution to meet the water-energy-food nexus in Southern Africa. In the framework of the Agrivoltaics concept, the main constrains, opportunities and parameters to consider its applicability are presented and discussed, in terms of its technical, economic, environmental and social impacts. In the second phase of this work the developing of a PEM electrolyser for connection to a solar PV power source and a fuel cell device, for a stand-alone application, is proposed, ensuring high reliability and energy conversion efficiencies, as well as adequate transient response and a competitive cost. It is intended as a low-carbon energy system, realising the potential for synergy in the Agrivoltaic concept, aligned with global and regional sustainability goals.
- Polyhydroxyalkanoate Production from Eucalyptus Bark's Enzymatic HydrolysatePublication . Rodrigues, Thomas; Torres, Cristiana A. V.; Marques, Susana; Gírio, Francisco; Freitas, Filomena; Reis, Maria A.ABSTRACT: In recent years, polyhydroxyalkanoates (PHAs) have gained notoriety because of their desirable properties that include proven biodegradability, biocompatibility, and thermal stability, which make them suitable alternatives to fossil-based polymers. However, the widespread use of PHAs is still challenging because of their production costs, which are greatly associated with the cultivation medium used for bacterial cultivation. In Portugal, one-quarter of the forest area is covered by Eucalyptus globulus wood, making its residues a cheap, abundant, and sustainable potential carbon source for biotechnological uses. In this work, eucalyptus bark was used as the sole feedstock for PHA production in a circular bioeconomic approach. Eucalyptus bark hydrolysate was obtained after enzymatic saccharification using Cellic (R) CTec3, resulting in a sugar-rich solution containing glucose and xylose. Although with differing performances, several bacteria were able to grow and produce PHA with distinct compositions, using the enzymatic hydrolysate as the sole carbon source. Pseudomonas citronellolis NRRL B-2504 achieved a high cellular growth rate in bioreactor assays (24.4 +/- 0.15 g/L) but presented a low accumulation of a medium-chain-length PHA (mcl-PHA) comprising the monomers hydroxydecanoate (HD, 65%), hydroxydodecanoate (HDd, 25%), and hydroxytetradecanoate (HTd, 14%). Burkholderia thailandensis E264, on the other hand, reached a lower cellular growth rate (8.87 +/- 0.34 g/L) but showed a higher biopolymer accumulation, with a polyhydroxybutyrate (PHB) content in the cells of 12.3 wt.%. The new isolate, Pseudomonas sp., revealed that under nitrogen availability, it was able to reach a higher accumulation of the homopolymer PHB (31 wt.%). These results, although preliminary, demonstrate the suitability of eucalyptus bark's enzymatic hydrolysate as a feedstock for PHA production, thus offering an exciting avenue for achieving sustainable and environmentally responsible plastic products from an undervalued forestry waste.
- A Corrosão em ImagensPublication . Simões, Alda; Sushkova, Alesia; Alves, Alexandra; Franco, Alexandra; Sá, Ana Isabel; Mata, Ana Leonor; Pereira, Ana Marisa; Vieira, Ana Soares; Carreira, André; Fróis, António; Franco, Carlos; Brites, Cármen; Louro, Cristina Santos; Godinho, Delfina; Nascimento, Filipe; Lopes, Helena; Martins, Inês Isabel; Alves, Isabel Nascimento; Silva, Joana Leal da; Santos, José António dos; Martins, José Inácio; Roseiro, J. Carlos; Côrte-Real, Leonor; Andrada, Luís; Pericão, Mafalda Sofia; Lemos, Manuel; Marques, Maria João; Plancha, Maria João; Santos, Maria Teresa; Gonçalves, Rita; Fontinha, Rute; Augusto, Sónia Nascimento; Páscoa, Soraia; Dias, Susana; Cunha Diamantino, Teresa; Paiva Luís, Teresa; Nunes, Vitor Manuel; Morozov, YegorPREFÁCIO: No vasto panorama da ciência dos materiais, Portugal, abriga uma comunidade multidisciplinar dedicada ao estudo da corrosão e da proteção de materiais. Neste contexto, as Jornadas de Corrosão e Proteção de Materiais nascem como um evento crucial, marcado pela sua natureza técnico-científica. Estas jornadas são um fórum de divulgação e de discussão dos resultados da investigação científica e do desenvolvimento tecnológico no domínio da corrosão e proteção de materiais. As jornadas são, assim, um ponto de encontro onde os corrosionistas se unem para discutir os novos desafios da corrosão e propor soluções que impulsionem o avanço nesta área essencial da ciência dos materiais. As Jornadas de Corrosão e Proteção de Materiais tiveram a primeira edição em 1998, organizadas pelo Instituto Nacional de Engenharia e Tecnologia Industrial (INETI). Desde então, oito edições enriqueceram o calendário técnico-científico, com as mais recentes organizadas pelo Laboratório Nacional de Energia e Geologia (LNEG) com o apoio da Sociedade Portuguesa de Materiais (SPM) através da sua Divisão Técnica de Corrosão e Proteção de Materiais (DTCPM). Esta parceria entre o LNEG e a DTCPM emerge pelos seus objetivos comuns, de promover o conhecimento, a divulgação e a colaboração entre as entidades do sistema científico e tecnológico e as empresas, no domínio da corrosão e proteção de materiais. Nas últimas edições das Jornadas introduziu-se um Concurso de Fotografia. Mas, porquê um concurso de fotografia numas Jornadas técnico-científicas? Uma fotografia tem o incrível poder de transcender palavras, transmitindo significados e emoções de maneiras que a linguagem muitas vezes não consegue. É uma combinação complexa de elementos visuais, emoções e significados que a tornam verdadeiramente especial. O concurso de fotografia tornou-se um marco destas Jornadas, impulsionado pelo crescente entusiasmo dos talentosos amadores e pela curiosidade de todos os participantes. Mais do que uma simples competição, este evento transformouse num elo emocional, conectando pessoas e estimulando uma troca de ideias diversificada sobre o modo de ver os fenómenos da corrosão. É uma celebração da criatividade, empatia e da riqueza de perspetivas que cada imagem pode oferecer. Neste contexto, surge este livro como uma narrativa visual que transcende as fronteiras da comunidade técnico-científica. Sentimos que era natural compartilhar com uma audiência mais ampla as fotografias que têm sido apresentadas nos concursos, documentando-as e elevando-as a outro patamar. Mais do que apenas apresentar um conjunto de fotografias, o nosso objetivo é convidá-los a contemplar a corrosão e a proteção de materiais com uma nova perspetiva, a mergulhar nos pormenores muitas vezes negligenciados e a descobrir a beleza oculta dos fenómenos de corrosão e degradação dos materiais.