Browsing by Issue Date, starting with "2022-06"
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- Integrated perspective on microbe-based production of itaconic acid: from metabolic and strain engineering to upstream and downstream strategiesPublication . Nascimento, Miguel Figueiredo; Marques, Nuno; Correia, Joana; Faria, Nuno Torres; Mira, Nuno P.; Ferreira, Frederico CasteloABSTRACT: The discovery of itaconic acid as a product of citric acid pyrolytic distillation in 1837 opened the possibility of using it as a polymer building block. Itaconic acid, featuring two carboxylic acids and an unsaturated group, can potentially be used as a building block in several chemical syntheses, with a particular emphasis on polymer manufacture. The elucidation of biochemical pathways originating from itaconic acid, first in Aspergillus terreus and, recently, in several species of the Ustilago genus, has intensified and diversified research focused on microbe-based itaconic acid production, including at an industrial scale. These efforts include the engineering of naturally producing species/strains along with the exploration of other species that do not naturally produce itaconic acid but may offer potential benefits. The use of renewable wastes or sugar-enriched residues as substrates to produce itaconic acid, from a circular bioeconomy perspective, is another important aspect of the advancements in microbial itaconic acid production. This review provides an overview of the achievements as well as the challenges concerning the engineering of the producing strains/species, substrate selection, optimisation of bioreactor operation, and downstream itaconic acid purification methods.
- Simulated hydropower production under climate change scenarios at Torrão reservoir, in northern PortugalPublication . Diogo, Paulo; Mujtaba, Babar; Beça, Pedro; Simoes, Sofia; Fortes, Patricia; Amorim, FilipaABSTRACT: Climate conditions have a significant impact on energy demand and production. The project CLIM2POWER, completed in 2021, aimed to develop a climate service at European scale for the planning of the power infrastructures operations using seasonal forecasts and long-term climate projections. This work presents part of the project, and focus on assessing the climate change impacts on hydropower production of Torrão Dam. Torrão reservoir is located on the Tâmega river, a tributary of the Douro river in northern Portugal. The long-term (2016-2100) climate data used is obtained from the EURO-CORDEX simulations, on a daily time scale. Two different combinations of regional and global climate models for scenarios RCP 4.5 and 8.5 (four combinations) were used: ICHEC-EC-EARTH-CLMcom-CCLM4 (CCLM4) and ICHEC-EC-EARTH-DMI-HIRHAM5 (HIRMAM5). Long-term precipitation data was bias-corrected using the multiplicative shift method, and for rainfall-runoff simulation, HEC-HMS model was used. The results showed that 30-years total annual precipitation for future periods (i.e, 2016-2040, 2041-2070 and 2071-2100) was 3.4%-28.1% lower than the historical one. 30-years annual total discharges of all future periods decreased for both models and RCPs (1.2%-30.2% less than the historical ones). Regarding future 30-year annual average capacity factors, there was reduction (1.8%-24.8%) with respect to historical one, except in two future periods for CCLM4 model of RCP 4.5 scenario i.e., 1.2% increased in the period 2016-2040 and 1.5% increased in the period 1971-2100. This suggest that hydropower production is not only dependent on future precipitation trends but also on the hydropower production procedures.
- Mamíferos Miocénicos do Museu Décio Thadeu das jazidas de Azambujeira e Quinta do Marmelal na margem direita do rio TejoPublication . Madeira Mateus, Simão Gustavo; Marinheiro, João; López-Rojas, Víctor; Pereira, Manuel F.C.RESUMO: Apresenta-se a revisão do acervo fóssil de mamíferos Miocénicos das jazidas da Azambujeira e da Quinta do Marmelal localizadas na margem direita do rio Tejo, distrito de Santarém, depositados no Museu Décio Thadeu, do Instituto Superior Técnico, da Universidade de Lisboa. Este acervo fóssil foi depositado em 1921, nunca tendo sido propriamente inventariado desde a sua incorporação. Neste estudo, criou-se um registo para todo o acervo aqui apresentado, com termos que foram uniformizados, e da revisão resultou a atualização da lista da fauna já descrita e à guarda do referido museu. Complementou-se o trabalho com um enquadramento histórico do museu e dos intervenientes que levaram à incorporação e estudo original da coleção objeto deste trabalho.
- Moesziomyces spp. cultivation using cheese whey: new yeast extract-free media, beta-galactosidase biosynthesis and mannosylerythritol lipids productionPublication . Nascimento, Miguel Figueiredo; Barreiros, Ricardo; Oliveira, Ana Cristina; Ferreira, Frederico Castelo; Faria, Nuno TorresABSTRACT: Mannosylerythritol lipids (MELs) are biosurfactants with excellent biochemical properties and a wide range of potential applications. However, high production costs, low productivity and unsatisfactory scale-up production have hampered commercial adoption. Herein, we report for the first time the beta-galactosidase production by Moesziomyces spp. from different sugars (D-galactose, D-glucose and D-lactose), with D-galactose being the best beta-galactosidase inducer, with 11.2 and 63.1 IU/mg(biomass), for Moesziomyces aphidis 5535(T) and Moesziomyces antarcticus 5048(T), respectively. The production of this enzyme allows to break down D-lactose and thus to produce MEL directly from D-lactose or cheese whey (a cheese industry by-product). Remarkably, when CW was used as sole media component (carbon and mineral source), in combination with waste frying oil, MEL productivities were very close (1.40 and 1.31 g(MEL)/L/day) to the ones obtained with optimized medium containing yeast extract (1.92 and 1.50 g(MEL)/g(susbtrate)), both for M. antarcticus and M. aphidis. The low-cost, facile and efficient process which generates large amounts of MELs potentiates its industrialization.
- Structural and optical characterization of mechanochemically synthesized CuSbS2 compoundsPublication . Esperto, Luís; Figueira, Isabel; Mascarenhas, João; Silva, Teresa; Correia, J.B.; Neves, FilipeABSTRACT: One of the areas of research on materials for thin-film solar cells focuses on replacing In and Ga with more earth-abundant elements. In that respect, chalcostibite (CuSbS2) is being considered as a promising environmentally friendly and cost-effective photovoltaic absorber material. In the present work, single CuSbS2 phase was synthesized directly by a short-duration (2 h) mechanochemical-synthesis step starting from mixtures of elemental powders. X-ray diffraction analysis of the synthesized CuSbS2 powders revealed a good agreement with the orthorhombic chalcostibite phase, space group Pnma, and a crystallite size of 26 nm. Particle-size characterization revealed a multimodal distribution with a median diameter ranging from of 2.93 mu m to 3.10 mu m. The thermal stability of the synthesized CuSbS2 powders was evaluated by thermogravimetry and differential thermal analysis. No phase change was observed by heat-treating the mechanochemically synthesized powders at 350 degrees C for 24 h. By UV-VIS-NIR spectroscopy the optical band gap was determined to be 1.41 eV, suggesting that the mechanochemically synthesized CuSbS2 can be considered suitable to be used as absorber materials. Overall, the results show that the mechanochemical process is a viable route for the synthesis of materials for photovoltaic applications.
- Palynological Report Alvalade: Sesmarias IIPublication . Pereira, Zélia; Mendes, Márcia
- New evidence of Late Cretaceous magmatism on the offshore central West Iberian Margin (Estremadura Spur) from potential field dataPublication . Escada, Cláudia; Represas, Patricia; Santos, Fernando Monteiro; Pereira, Ricardo; Mata, João; Rosas, Filipe M.ABSTRACT: The West Iberian Margin (WIM) is a key example of a magma-poor passive margin, punctuated by several postrift magmatic manifestations that are part of the Late Cretaceous Atlantic Alkaline Province. In this work, potential field (gravity and magnetics) data, constrained by 3D multichannel seismic reflection data, are used to describe and characterise the geometry and nature of magmatic features located offshore the central segment of the margin, the Estremadura Spur. The estimated geometry and nature of the magmatic features was achieved through the integration of 3D gravity and magnetic inversion and 2D magnetic forward modelling. The results provide an insightful 3D subsurface model revealing that: 1) the Estremadura Spur Intrusion represents a 28 x 15 km wide laccolith with an overall granitic nature and an estimated density of 2490-2640 kg/m3 and 0.01-0.05 SI magnetic susceptibility, 2) the 26 x 17 km Fontanelas buried volcano is dominantly basaltic, with density values of 2500-2821 kg/m3 and magnetic susceptibility of 0.01 to 0.0875 SI, and 3) multiple sill complexes intruded the region, thus producing a higher magnetic background on otherwise inconspicuous anomalies The models allowed achieving a confident fit suggesting that both the ESI and the Fontanelas volcano are coeval with the outcropping magmatic features from this same magmatic event. Additionally, the results support that Late Cretaceous alkaline magmatism on the West Iberian Margin is more significant than anticipated and provide further evidence to clarify unclear geometrical aspects of similar intrusions observed onshore. Acknowledging the geometry and nature of these magmatic entities allows to better understand the role of postrift intra-plate magmatism on continental hyper-extended rifted margins by clarifying how shallow plumbing systems evolve in these settings.
- General review of titanium ores in exploitation: present status and forecastPublication . Subasinghe, Hevapathiranage Chandima Sudantha; Ratnayake, Amila SandaruwanABSTRACT: Titanium ore minerals have a unique spectrum of properties useful for modern-day industrial applications. This study focuses on the global distribution, genesis, processing, and economics of titanium ore minerals. Titanium ore deposits are distributed in 20 countries. Ilmenite (FeOTiO2), leucoxene (Fe2O3.nTiO2), and rutile (TiO2) are the major Ti ores. Titanium ore minerals in rocks (i.e., primary deposits) are products of magmatic, hydrothermal, metasomatic, and metamorphic processes. Titanium ore minerals are also concentrated as unconsolidated/placer deposits (i.e., secondary deposits) due to weathering (chemical, physical and biological), erosion, and transportation of sediments. About 60% of global Ti ore production comes from unconsolidated mineral sand deposits. China is the leading producer of ilmenite accounting for 31% of global production, primarily from hard-rock deposits. Australia and South Africa are also leading producers of ilmenite. In addition, Australia leads rutile production with a global share of 52%. Titanium ore minerals are used to extract TiO2 and Ti metal, using three major processes pyrometallurgy, hydrometallurgy, and electrometallurgy. Therefore, processed TiO2 and Ti metal are used in advanced applications such as the production of paints, aircraft, photovoltaic cells, medicines, and biomedical engineering. Substitutions are virtually impossible in most applications of TiO2 due to its unique physical and chemical properties. Time series analysis and forecast (using the R studio software) of global production and price variations of ilmenite and rutile indicate satisfactory growth rates, based on the United States Geological Survey (USGS) database and mineral yearbooks over 65 years from 1950 to 2015.
- Um esquisso setecentista da área da “Mina de carvão de pedra do Focinho do Monte” (Cabo Mondego, Portugal)Publication . Brandão, José Manuel Moraes ValeRESUMO: O propósito deste artigo é o de contextualizar e apresentar, o que deve ter sido o primeiro esquisso do campo mineiro do Cabo Mondego (Figueira da Foz), então designado por “Focinho do Monte”, onde se representam, de forma muito simplificada os principais traços morfológicos do promontório da Serra da Boa Viagem e a disposição relativa das cinco camadas de carvão então conhecidas, cujas características se sumarizam numa legenda desenvolvida. Não obstante a ausência de quaisquer datas e/ou assinaturas que, em primeira análise, permitam ajuizar com alguma segurança a origem do manuscrito, o seu cruzamento com outros documentos permite admitir que terá sido elaborado na segunda metade do século XVIII, ao tempo do Marquês de Pombal, pelos tenentes do Exército Português Galego Soromenho e Nunes de Figueiredo, ali enviados pelo ministro Martinho de Melo e Castro, pouco antes do surgimento do bem conhecido mapa de Guilherme (William) Elsden, levantado em 1773.
- Assessing the industrial effects of the deployment of renewable energy technologies: when product identity mattersPublication . Barbosa, Juliana; Fontes, Margarida; Bento, NunoABSTRACT: Investment in renewable energy technologies (RET) produces impacts on economic activity and job creation that are fundamental to increase the social acceptability of those technologies. Previous research that attempted to measure the impacts of RET has mainly focused on its effects in energy production and climate mitigation, but surprisingly little is known about the potential of RET to transform the industrial structure of an economy. This paper proposes a methodology to understand and measure the industrial transformative impact of RET. The paper draws on contributions from the sustainability transitions literature and from the economic literature that analyses the socioeconomic impacts of RET, and combine them with the economic complexity literature in order to address two main gaps: the lack of measurement of industrial transformative effects in the first; and the assumption of product homogeneity in the second that precludes an assessment of more structural impacts. We develop a conceptual approach to the way technology deployment can lead to changes in the industrial structure, centered on the notion of product heterogeneity intrinsic to the economic complexity literature. We advance three main dimensions along which to measure the changes in the industrial structure driven by modifications in the basket of products being produced due to the development of the technology value chain: sophistication, connectivity, and competitiveness. We also propose a more precise delineation of the industrial value chain of the technology, by considering the actual weights of each sector to the technology and the technology to each sector. This approach is applied to the case of wind energy in Portugal (a successful fast follower), compared with three other main wind energy producers (Spain, Denmark, Germany). The results show a strong relationship between the deployment of the technology and the sophistication and the competitiveness of the Æcloud of productsÆ composing the industrial value chain. The paper proposes a novel analytical framework and measurement tools that can support a timely assessment of the effects of sustainable energy technologies in the industrial structure, with relevance for policy.
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