Browsing by Issue Date, starting with "2024-09"
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- Optimizing deep eutectic solvent pretreatment for enhanced glucan recovery from miscanthusPublication . Piedade, Patrícia J.; Nowotarski, Michal M.; Dudek, Gabriela; Lukasik, Rafal M.ABSTRACT: This work focuses on the use of the deep eutectic solvent composed of choline chloride and acetic acid (1 : 2) in the pretreatment of the perennial energy crop Miscanthus, commonly called silvergrass. The pretreatment time and temperature were optimized to achieve a maximum of the glucan and minimum of the lignin contents in the pretreated biomass. In the optimization approach, the maximal glucan recovery in the pretreated solid was also considered. The performed optimization resulted in conditions (2 h 52 min and 150 degrees C), at which a pretreated biomass contained 74.1 wt% and 9.5 wt% of glucan and lignin respectively, and a glucan recovery was as high as 87.0 wt%. Furthermore, the biocompatibility of deep eutectic solvent was evaluated by using enzymatic hydrolysis washed and unwashed pretreated biomass produced at optimal conditions. The enzymatic hydrolysis of washed biomass resulted in higher glucan and xylan conversion than those achieved from unwashed biomass, deeming the step of biomass washing necessary. This was confirmed by the fractal kinetics modelling that confirmed higher accessibility of glucan for washed biomass than for unwashed Miscanthus sample.
- Uma abordagem de sensores multi-escala para áreas mineiras no sul de Portugal: do satélite ao sUASA [Resumo]Publication . Gonçalves, Pedro; Quental, Lídia; Patinha, Pedro; de Oliveira, Daniel Pipa SoaresRESUMO: A deteção remota com recurso a satélites e sUAS fornecem informações cruciais, particularmente em geologia, permitindo a discriminação de unidades litológicas, características estruturais e ocorrências minerais. As imagens de alta resolução espectral, espacial e temporal permitem uma análise mais detalhada e apoiam na identificação de zonas de alteração que podem indicar ocorrências minerais e gerar dados valiosos nas várias fases do ciclo de vida da mina.
- Enhancing Resilience of Hot Spring Ecosystems Towards a Model of Sustainable Management of SPA Territories, Driving Innovation and Energy transition [Poster]Publication . Bertin, C.; Iasio, C.; Herms, Ignasi; Arnó, Georgina; Carvalho, João; Ramalho, Elsa; Becerra, S.; Roussel, M.; Brut, E.ABSTRACT: The climate observation systems have classified 2020, 2022, 2019, 2015, and 2014 as the five hottest years in Europe over the past four decades. In the SUDOE region, 2022 was the warmest year since 1950. The projected long-term decline in precipitation in the SUDOE region may alter the natural properties of thermal springs, by changes in of shallow and deep groundwater mixing, impacting their anthropogenic ecosystem. Currently, there is no data assessing the impact of climate change, nor is there any adaptation strategy in place to anticipate its socio-economic consequences. Data on groundwater quality, climate change vulnerability, and territorial adaptive capacity are heterogeneous, exacerbating the economic divide. Migration movements and indirect impacts of climate change, as such as pandemic crises, may further intensify stress on water resources and the economy.
- Screening and Engineering Yeast Transporters to Improve Cellobiose Fermentation by Recombinant Saccharomyces cerevisiaePublication . Kretzer, Leonardo; Knychala, Marília; Silva, Lucca C.; Fontoura, Isadora C.C.; Leandro, Maria José; Fonseca, César; Verstrepen, Kevin J.; Stambuk, BorisABSTRACT: Developing recombinant Saccharomyces cerevisiae strains capable of transporting and fermenting cellobiose directly is a promising strategy for second-generation ethanol production from lignocellulosic biomass. In this study, we cloned and expressed in the S. cerevisiae CEN.PK2-1C strain an intracellular beta-glucosidase (SpBGL7) from Spathaspora passalidarum and co-expressed the cellobiose transporter SiHXT2.4 from Scheffersomyces illinoinensis, and two putative transporters, one from Candida tropicalis (CtCBT1 gene), and one from Meyerozyma guilliermondii (MgCBT2 gene). While all three transporters allowed cell growth on cellobiose, only the MgCBT2 permease allowed cellobiose fermentation, although cellobiose consumption was incomplete. The analysis of the beta-glucosidase and transport activities revealed that the cells stopped consuming cellobiose due to a drop in the transport activity. Since ubiquitinylation of lysine residues at the N- or C-terminal domains of the permease are involved in the endocytosis and degradation of sugar transporters, we constructed truncated versions of the permease lacking lysine residues at the C-terminal domain (MgCBT2 Delta C), and at both the C- and N-terminal domain (MgCBT2 Delta N Delta C) and co-expressed these permeases with the SpBGL7 beta-glucosidase in an industrial strain. While the strain harboring the MgCBT2 Delta C transporter continued to produce incomplete cellobiose fermentations as the wild-type MgCBT2 permease, the strain with the MgCBT2 Delta N Delta C permease was able to consume and ferment all the cellobiose present in the medium. Thus, our results highlight the importance of expressing cellobiose transporters lacking lysine at the N- and C-terminal domains for efficient cellobiose fermentation by recombinant S. cerevisiae.
- Método de produção em contínuo de biocatalizadores com atividade de biodessulfurização utilizando fontes de enxofre inibitórias - Patente nacional: PT 118539 (A)Publication . Alves, Luís; Paixão, Susana M.; Silva, TiagoRESUMO: A presente invenção traduz-se num método para a produção em cultura contínua de células microbianas e/ou biocatalizadores, com atividade de biodessulfurização, utilizando fontes de enxofre inibitórias, como as fontes de enxofre facilmente metabolizáveis, através do controlo da concentração relativa do enxofre, para que este seja sempre o nutriente limitante.
- Thermal Shock Resistance of Commercial Oxide-Bonded Silicon Carbide Reticulated Foams under Concentrated Solar Radiation at PSA: A Feasibility StudyPublication . Oliveira, Fernando Almeida Costa; Galindo, José; Rodriguez, Jose; Cañadas, Inmaculada; Fernandes, Jorge CruzABSTRACT: Volumetric ceramic receivers can be regarded as a promising technology to heat air above 1000 ◦C for solar thermal electricity production. In this study, the thermal shock behavior of commercial 10 ppi (A) and 20 ppi (B) oxide-bonded silicon carbide (ob-SiC) reticulated porous ceramic (RPC) foams was evaluated using the SF60 solar furnace at Plataforma Solar de Almería. The foams were subjected to well-controlled temperature cycles ranging from 800 to 1000, 1200, 1300 or 1400 ◦C, for 25, 100, and 150 cycles. The extent of the damage after thermal shock was determined by crushing tests. The damage was found to be critically dependent on both the bulk density and cell size. Decreasing both the bulk density and cell size resulted in better thermal shock resistance. The B foam exhibited approximately half the stress degradation compared to the A foam when exposed to a temperature difference of 600 K (in the range of 800 to 1400 ◦C) and subjected to 150 cycles.
- New Greenhouse Gas simulation and mapping tools to support local carbon neutrality agendas: application to the city of AlmadaPublication . Amorim, Filipa; Simoes, Sofia; Barbosa, Juliana; Oliveira, Paula; Trindade, Paula; Aelenei, Laura Elena; Catarino, Justina; Viana, Susana; Figueiredo, LeonorABSTRACT: The aim of this work is to develop three innovative decision support tools: (1) a scenario tool that enables users to interactively design scenarios of activity variables that support decarbonisation trajectories on a local scale; (2) a mitigation tool that translates scenarios into greenhouse gas (GHG) emissions, taking into account the identification and prioritisation of the most innovative, cost-effective mitigation options (technological and behavioural) for Portuguese municipalities; and (3) a mapping tool to identify GHG emissions ‘hot spots’ on a local scale. In the first phase, these tools are applied and tested for the case study of the city of Almada in support of the ‘Agenda for a Carbon Neutral Almada by 2050’. These tools will also contribute to the training and involvement of local stakeholders, to improve the design of local GHG emissions mitigation strategies and roadmap. In the second phase, these tools will be further developed so they can be used in other Portuguese municipalities.
- Contribution of the time domain electromagnetic method to the study of the Kalahari transboundary multilayered aquifer systems in Southern AngolaPublication . Francés, Alain Pascal; Ramalho, Elsa; Santos, Fernando Monteiro; Llorente, J.; Mateus, T.; Martín-Banda, Raquel; Cuervo, I.; Lobón, Jose Luis Garcia; Dala, V.; Ditutala, M.; Famorosa, A.; Victorino, Américo da MataABSTRACT: The Cunene Province (Southern Angola) is facing recurrent and pluriannual droughts. Surface water supply could be reinforced using the groundwater resources of the multilayered aquifer systems (MAS) hosted in the siliciclastic sediments of the Kalahari Group. The MAS were first identified in the early 2000s in Northern Namibia and recently in the Cunene Province, by studies of the PLANAGEO project based on modern processing and reinterpretation of legacy data from the 1960s and 1970s (electrical resistivity data and deep boreholes). This article presents the results of a time domain electromagnetic (TDEM) survey conducted in the Cunene Province to: (i) contribute to the design of the hydrogeological conceptual model of the transboundary MAS, namely their geometry and extension; (ii) validate the reprocessing of the legacy data; and (iii) guide the future location of boreholes. Results depict the geometry of the sedimentary basin and the characterization of the MAS, with particular emphasis on the intermediate and deep aquifers. The borehole siting, based on the interpretation of the new TDEM data and the legacy data (clay markers in borehole logs), was successful, with a good agreement between estimated and observed horizons of the deep aquifers. However, the presence of clayey layers, a clay-rich matrix in the detrital deposits and saline/brackish groundwater led to uncertainties in the interpretation of the electrical transects. As such, recommendations are made to improve future data collection and mapping of the MAS.
- Uma abordagem de sensores multi-escala para áreas mineiras no sul de Portugal: do satélite ao sUASA [Poster]Publication . Gonçalves, Pedro; Quental, Lídia; Patinha, Pedro; de Oliveira, Daniel Pipa Soares
- Multi-Scenario-Based Strategic Deployment of Electric Vehicle Ultra-Fast Charging Stations in a Radial Distribution NetworkPublication . Nandi, Sharmistha; Ghatak, Sriparna Roy; Acharjee, Parimal; Lopes, FernandoABSTRACT: In the present work, a strategic multi-scenario EV ultra-fast charging station (CS) planning framework is designed to provide advantages to charging station owners, Distribution Network Operators, and EV owners. Locations of CSs are identified using zonal division and the Voltage Stability Index strategy. The number of chargers is determined using the Harris Hawk Optimization (HHO) technique while minimizing the installation, operational costs of CS, and energy loss costs considering all the power system security constraints. To ensure a realistic planning model, uncertainties in EV charging behavior and electricity prices are managed through the 2m-Point Estimate Method. This method produces multiple scenarios of uncertain parameters, which effectively represent the actual dataset, thereby facilitating comprehensive multi-scenario planning. This study incorporates annual EV and system load growth in a long-term planning model of ten years, ensuring the distribution network meets future demand for sustainable transportation infrastructure. The proposed research work is tested on a 33-bus distribution network and a 51-bus real Indian distribution network. To evaluate the financial and environmental benefits of the planning, a cost-benefit analysis in terms of the Return-on-Investment index and a carbon emission analysis are performed, respectively. Furthermore, to prove the efficacy of the HHO technique, the results are compared with several existing algorithms.