Browsing by Issue Date, starting with "2024-01"
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- The role of research-based spin-offs in innovation ecosystemsPublication . Conceição, Oscarina; Sousa, Cristina; Fontes, MargaridaABSTRACT: The objective of the paper is to contribute to a better understanding of the various roles played by research-based spin-offs (RBSOs) in knowledge dissemination. It investigates if RBSOs act as connectors and knowledge translators, both between different types of organisations within an innovation ecosystem and across different geographical scales and knowledge environments. This latter role has been relatively less investigated but is important to open local innovation ecosystems. The paper analyses the networks formed by Portuguese RBSOs in the context of research, technology and product development projects. The results suggest that RBSOs play an intermediary role in the country's innovation ecosystem, which can assume different forms. In the national networks, they frequently bridge research and downstream organisations, contributing to the dissemination of knowledge within the ecosystem. In the international networks, their most important role may be as connectors and conveyors of advanced knowledge produced in external knowledge environments
- Geophysical characterization of the Cercal Paleozoic structure, Iberian Pyrite Belt, from a mineral exploration perspectivePublication . Feitoza, L. M.; Carvalho, João; Represas, Patricia; Ramalho, Elsa; Sousa, Pedro; Matos, João Xavier; Albardeiro, Luís; Morais, Igor; Santos, Telmo M. Bento DosABSTRACT: The Cercal Volcano-Sedimentary Complex (Cercal VSC) structure is the westernmost sector of the Iberian Pyrite Belt (IPB) giant metallogenic province and was explored since Roman times for volcanogenic massive sulphides (VMS) and Fe–Mn (Ba) deposits. However, presently only a single deposit is known, the Salgadinho Cu-Ag-Au stockwork/disseminated deposit. Nevertheless, according to several mining companies that operated in the area during the last two decades, the Cercal area keeps a high potential for the discovery of new massive and stockwork mineralization deposits hosted in VSC felsic volcanic rocks. The lack of seismic data and deep drill holes (> 800 m), has been limiting the discovery of possible deep seated massive/stockwork deposits. The goal of this work is to provide new insights into the Cercal deep and near surface structure through the integrated interpretation of geophysical and geological data and contribute to the discovery of new stockwork or massive sulphide deposits. For this purpose, we reprocessed ground gravity, airborne magnetic/radiometric and electrical resistivity/induced polarization data which was interpreted and integrated with geological data. Data interpretation included 2.5D forward gravimetric modeling constrained by i) a new rock density database (from outcrops and drill-holes) built under the scope of this work, ii) the scarce available drill-holes and iii) geological information. A small magnetic susceptibility/conductivity database based on drill-hole core samples was also built to assist the magnetic and electrical/chargeability data interpretation. The integrated interpretation agrees with some of the expected geological scenarios predicted by surface mapping and exploration drill-hole logs in the IPB and provides further details on the deep structure of the Cercal Anticline, a NNW-SSE oriented VSC unrooted structure, controlled by variscan SW verging thrust faults and discordant strike-slip Late-Variscan faults. This geological scenario favors the possibility of new findings at relatively shallow depths (200–900 m), and a few sites for further exploration are indicated based on the integrated interpretation. Therefore, this work contributes to the understanding of the Cercal deep structure from a mineral exploration perspective and confirms the proposed structural models for the IPB’s westernmost region.
- Critical raw materials in the global high-throughput ceramic industryPublication . Garcia-Ten, Javier; Dondi, Michele; Lisboa, Jose; Cabedo, Monica Vicent; Perez-Villarejo, Luis; Rambaldi, Elisa; Zanelli, ChiaraABSTRACT: The high-throughput ceramic industry is exposed, at the global level, to the risk of shortage and/or sudden price growth of raw materials, particularly Critical Raw Materials (CRMs). The goal of the present study is to overview the dependence on CRMs of a sector transforming a large amount of mineral resources, i.e. the ceramic manufacturing and its supply chain (wall and floor tiles, sanitaryware and tableware, frits and glazes, pigments and inks, and so on). For this purpose, a critical assessment with expert consultation was carried out to quantify demand, uses, recycling and possible substitutes of CRMs. Such data allowed assessing the risk exposure for the ceramic industry at the global level, at the light of expected trends in production and demand for every CRM. The various subsectors into which the high-throughput ceramic industry is divided are exposed differently to supply risk. The production of inks, pigments, dyes and effects for ceramic decoration is mainly exposed to supply risk, and similarly that of frits, glazes and grinding media. End-users of these materials (in particular tile manufacturers) are equally exposed to risk, albeit indirectly. However, the direct use of CRMs in ceramic bodies occurs massively only for feldspar (in different percentages in wall and floor tiles, sanitaryware, and tableware). Other subsectors (silicate refractories and insulators, clay bricks and roof tiles, machinery components, etc.) do not make use of or only make occasional use of certain CRMs. The ceramic industry must implement actions to mitigate the different degrees of supply risk to which the CRM is exposed. The extreme risk (Cobalt and Praseodymium) makes it necessary to search for substitutes and technological solutions to reduce CRM consumption. These actions are also recommended in the case of high risk (Antimony and Lithium). The recommended actions to mitigate moderate risk (Barium, Bismuth, Borates, Feldspar, Tungsten, Vanadium and Yttrium) consist mainly of strengthening the supply chain and improving resource efficiency. No action appears to be necessary for low risk (Cerium, Manganese, Phosphate and Platinum Group), while no risk has been found for Fluorine and Niobium. To ensure the access to CRMs without disruptions, it is appropriate to envisage a medium-long term strategy, involving the various players in the ceramic supply chain.
- Evaluation of different fractionation methods for the simultaneous protein and carbohydrate extraction from microalgaePublication . Martins, Pedro L.; Duarte, Luís C.; Pereira, Helena; Reis, Alberto; Carvalheiro, FlorbelaABSTRACT: The production of high-value products from microalgae, one of the preferred emerging biorefineries' feedstocks, relies on the crucial step of biomass fractionation. In this work, the fractionation of Chlorella vulgaris and Scenedesmus obliquus biomass was tested for protein extraction using a wide range of physical, chemical, and enzymatic treatment combinations, including ultrasound, cell homogenizer, cellulase, and alcalase combinations in aqueous and alkali extraction conditions. The impact of these processes on biomass carbohydrates was also evaluated. Alkaline-assisted ultrasound treatments using alcalase presented the highest protein extraction yield, reaching 90 g/100 g protein on C. vulgaris, closely followed by the same treatment in aqueous conditions (85 g/100 g protein). The same aqueous treatment achieved the best performance on S. obliquus, reaching 82 g/100 g protein. All treatments on both microalgae partially solubilized the polysaccharide fraction with all alkaline treatments solubilizing over 50 g/100 g sugars for all conditions. Overall, all the treatments applied were effective methods for biomass fractionation, although they showed low selectivity regarding the individual extraction of protein or carbohydrates.
- Microwave-assisted hydrothermal processing of pine nut shells for oligosaccharide productionPublication . Torrado, Ivone; Neves, Beatriz Guapo; Fernandes, M. C.; Carvalheiro, Florbela; Pereira, Helena; Duarte, Luís C.ABSTRACT: Pine nut shells, a biomass residue from the Mediterranean Pinus pinea pine nut industrial processing, were treated by microwave-assisted autohydrolysis to produce xylo-oligosaccharides. Microwave-assisted processes provide alternative heating that may reduce energy input and increase overall process efficiency. The autohydrolysis treatments were performed under isothermal and non-isothermal operations within a wide range of operational conditions (temperature/reaction times) covering several severity regimes (as measured by the log R-0 severity factor). The composition of the autohydrolysis liquors was determined in terms of oligo- and monosaccharides, aliphatic acids and degradation compounds. The process was highly selective towards hemicelluloses hydrolysis and liquid streams containing a mixture of oligomeric compounds (mainly xylo-oligosaccharides) could be obtained under relatively mild operation conditions (190 degrees C, 30 min) with a maximal oligosaccharides' concentration of 18.48 g/L. The average polymerization degree of the obtained oligosaccharides was characterised by HPLC, showing that for the optimal conditions a mixture of oligomers with DPs from 2 to 6.
- The role of research-based spin-offs in innovation ecosystemsPublication . Conceição, Oscarina; Sousa, Cristina; Fontes, MargaridaABSTRACT: The objective of the paper is to contribute to a better understanding of the various roles played by research-based spin-offs (RBSOs) in knowledge dissemination. It investigates if RBSOs act as connectors and knowledge translators, both between different types of organisations within an innovation ecosystem and across different geographical scales and knowledge environments. This latter role has been relatively less investigated but is important to open local innovation ecosystems. The paper analyses the networks formed by Portuguese RBSOs in the context of research, technology and product development projects. The results suggest that RBSOs play an intermediary role in the country’s innovation ecosystem, which can assume different forms. In the national networks, they frequently bridge between research and downstream organisations, contributing to the dissemination of knowledge within the ecosystem. In the international networks, their most important role may be as connectors to and conveyors of advanced knowledge produced in external knowledge environments.
- Streamlining the biodesulfurization process: development of an integrated continuous system prototype using Gordonia alkanivorans strain 1B†Publication . Silva, Tiago; Paixão, Susana M.; Tavares, João; Paradela, Filipe; Crujeira, Teresa; Roseiro, J. Carlos; Alves, LuísABSTRACT: Biodesulfurization is a biotechnological process that uses microorganisms as biocatalysts to actively remove sulfur from fuels. It has the potential to be cleaner and more efficient than the current industrial process, however several bottlenecks have prevented its implementation. Additionally, most works propose models based on direct cultivation on fuel, or batch production of biocatalysts followed by a processing step before application to batch biodesulfurization, which are difficult to replicate at a larger scale. Thus, there is a need for a model that can be adapted to a refining process, where fuel is being continuously produced to meet consumer needs. The main goal of this work was to develop the first bench-scale continuous biodesulfurization system that integrates biocatalyst production, biodesulfurization and fuel separation, into a single continuous process, taking advantage of the method for the continuous production of the biodesulfurization biocatalysts previously established. This system eliminates the need to process the biocatalysts and facilitates fuel separation, while mitigating some of the process bottlenecks. First, using the bacterium Gordonia alkanivorans strain 1B, continuous culture conditions were optimized to double biocatalyst production, and the produced biocatalysts were applied in batch biphasic biodesulfurization assays for a better understanding of the influence of different factors. Then, the novel integrated system was developed and evaluated using a model fuel (n-heptane + dibenzothiophene) in continuous biodesulfurization assays. With this system strain 1B surpassed its highest biodesulfurization rate, reaching 21 μmol h−1 g−1. Furthermore, by testing a recalcitrant model fuel, composed of n-heptane with dibenzothiophene and three alkylated derivatives (with 109 ppm of sulfur), 72% biodesulfurization was achieved by repeatedly passing the same fuel through the system, maintaining a constant response throughout sequential biodesulfurization cycles. Lastly, the system was also tested with real fuels (used tire/plastic pyrolysis oil; sweet and sour crude oils), revealing increased desulfurization activity. These results highlight the potential of the continuous biodesulfurization system to accelerate the transition from bench to commercial scale, contributing to the development of biodesulfurization biorefineries, centered on the valorization of sulfur-rich residues/biomasses for energy production.