Browsing by Issue Date, starting with "2022-12"
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- Production of Mannosylerythritol Lipids Using Oils from Oleaginous Microalgae: Two Sequential Microorganism Culture ApproachPublication . Nascimento, Miguel Figueiredo; Coelho, Tiago; Reis, Alberto; Gouveia, Luisa; Faria, Nuno Torres; Ferreira, Frederico CasteloABSTRACT: Mannosylerythritol lipids (MELs) are biosurfactants with excellent biochemical properties and a wide range of potential applications. However, most of the studies focusing on MELs high titre production have been relying in the use of vegetable oils with impact on the sustainability and process economy. Herein, we report for the first time MELs production using oils produced from microalgae. The bio-oil was extracted from Neochloris oleoabundans and evaluated for their use as sole carbon source or in a co-substrate strategy, using as an additional carbon source D-glucose, on Moesziomyces spp. cultures to support cell growth and induce the production of MELs. Both Moesziomyces antarcticus and M. aphidis were able to grow and produce MELs using algae-derived bio-oils as a carbon source. Using a medium containing as carbon sources 40 g/L of D-glucose and 20 g/L of bio-oils, Moesziomyces antarcticus and M. aphidis produced 12.47 +/- 0.28 and 5.72 +/- 2.32 g/L of MELs, respectively. Interestingly, there are no significant differences in productivity when using oils from microalgae or vegetable oils as carbon sources. The MELs productivities achieved were 1.78 +/- 0.04 and 1.99 +/- 0.12 g/L/h, respectively, for M. antarcticus fed with algae-derived or vegetable oils. These results open new perspectives for the production of MELs in systems combining different microorganisms.
- Greenwashing and sustainable fashion industryPublication . Adamkiewicz, Julia; Kochanska, Ewa; Adamkiewicz, Iwona; Lukasik, Rafal M.ABSTRACT: The fashion industry is now in the eye of the storm for what concerns sustainability because of the enormous impact that such a business area has on the environment. To exploit the full potential for circular economy implementation, the fashion industry requires urgent changes adapting much more con-scientious business practices, driving consumers to change their perceptions and behaviors toward circular products and services. The renunciation of greenwashing practices and the use of strategy focused on regaining consumer's trust will in-crease the positive sentiment toward the fashion brands. This work demonstrates to what extent greenwashing may jeopar-dize the fashion industry in addressing challenges related to the implementation of more sustainable circular economy in the context of designing with intention of recycle, reduction of by-products, lower energy consumption, and wise purchase habits. This study provides guides for fashion brands about the risks and gains related to the greenwashing practices and sustain-able fashion industry.This study sketches also future research opportunities in more sustainable holistic approach of a prod-ucts' life cycle and how this can be translated into clear, transparent, or reliable certification schemes to prevent the misleading and dishonest marketing strategies helping the consumers to make a responsible choice.
- Comparison of descaling methods to study the corrosion kinetics of ferritic steels after dynamic exposure to molten carbonatesPublication . Audigié, Pauline; Rodríguez Catela, Sergio; Agüero, Alina; Pedrosa, Fátima; Paiva Luís, Teresa; Cunha Diamantino, TeresaABSTRACT: T91 ferritic-martensitic steel was exposed to Li, Na and K molten carbonates at 650??C under dynamic conditions up to 1000 h. After testing, three descaling methods, two from the ISO8407 and one from the ISO17245 stan-dards were applied to remove the corrosion products and determine the corrosion rates. The two ISO8407 methods were more appropriate although the procedure required several steps to fully remove the corrosion products. The ISO17245 method led to a higher mass loss affecting probably the base material. Oxides identi-fication was performed by XRD following step by step layers removal. Li-, Na-, K-containing oxides and chro-mates/chromites were detected.
- Efeitos sectoriais e territoriais da experimentação em fases iniciais de inovações energéticas: lições de 20 anos de tecnologias renováveis marinhas em PortugalPublication . Fontes, Margarida; Aguiar, Mariana; Bento, NunoRESUMO: A urgência climática e questões mais conjunturais como pandemias e guerras apontam para a necessidade de acelerar a transição sustentável e, particularmente, o desenvolvimento e implementação de novas tecnologias de energias renováveis. Essa aceleração depende crucialmente da capacidade de mobilizar recursos e competências existentes no território. A passagem a uma fase comercial coloca desafios importantes, que podem ser enfrentados com base nas capacidades adquiridas na fase inicial de experimentação, cujos efeitos permanecem pouco estudados. Portugal tem uma experiência longa no desenvolvimento de tecnologias de energias renováveis marinhas – energia das ondas e energia eólica offshore flutuante. Importa agora compreender, através de uma análise longitudinal suportada na construção de uma base de dados dos atores envolvidos, se as atividades conduzidas ao longo da fase inicial de desenvolvimento permitiram começar a mobilizar a indústria nacional e gerar núcleos sectoriais e regionais de atividade que possam suportar uma evolução futura. As análises apontam para a importância dos projetos de teste e demonstração na mobilização de empresas de sectores relevantes, embora a capacidade para atrair empresas locais seja ainda limitada, e revelam redes de empresas distribuídas pelo território, com predominância das principais áreas metropolitanas. Estes resultados podem informar estratégias para acelerar a difusão destas tecnologias, contribuindo para a transformação industrial.
- Type specimens alone have a strong correlation with taxa record by geological epoch: the case study of the fossil vertebrates named from Portuguese typesPublication . Mateus, Octávio; Estraviz López, Darío; Madeira Mateus, Simão GustavoABSTRACT: Type specimens (holotypes, neotypes, syntypes, etc.) are of crucial importance because they are the only tangible evidence of the nomenclatural act that supports the understanding of paleobiodiversity. The list of the vertebrate species whose type specimen is based on fossils from Portugal is presented here. We counted 206 species, of which there are 45 bony fishes, 39 Late Jurassic Mammaliamorpha, 33 Cenozoic mammals, 28 non-avian dinosaurs, 25 non-dinosaur reptiles, 11 Cenozoic Aves, 22 Chondrichthyes and three other vertebrates. Except for the Quaternary fossil record, the type specimens can be used as a shortcut for measuring the fossil record and paleobiodiversity through geological time and rock units because they correlate in 95% with the fossil record by epoch in the case-study of fossil vertebrates of Portugal.
- Detrital zircon similarities and dissimilarities between the Iberian Pyrite Belt, Ossa-Morena Zone and MegumaPublication . Amaral, Joao Lains; Solá, A. Rita; Santos, Telmo M. Bento Dos; Chichorro, MartimABSTRACT: Despite the so-called exotic nature of the South Portuguese Zone relatively to the other major domains of the Iberian Massif of peri-Gondwanan affinity, Devonian detrital rocks of the oldest strata in the Iberian Pyrite Belt have a remarkable resemblance with the Ossa-Morena Zone’s Neoproterozoic-Cambrian rocks and the West Meguma’s Cambrian-Ordovician rocks, presenting the so-called “West African signature”.Using published U-Pb detrital zircon data, we discuss the similarities and dissimilarities between the Iberian Pyrite Belt, Ossa-Morena Zone and West Meguma Terrane through multidimensional scaling, comparing them with other zones of the Iberian Massif, Saxo-Thuringian Zone, Avalonia-Ganderia, and the North African cratonic regions. Our findings show that multidimensional scaling is not entirely effective in displaying the dissimilarities between the peri-Gondwanan terranes due to the background noise caused by the overwhelming number of Cadomian-Panafrican ages. However, it becomes a powerful tool if these ages are filtered. A dominant Meguma-type provenance (Cambro-Ordovician) for the Middle-Upper Devonian rocks of the Iberian Pyrite Belt is demonstrated, mainly attending to their similar Birimian-Eburnean pattern. The possibility of minor contributions from the lower Cambrian rocks of the Ossa-Morena Zone into the Iberian Pyrite Belt quartzites is unlikely, as the latter lack the 1.9Ga peak that characterises the Ossa-Morena Zone sediments. Additionally, the remarkable similarities between Ossa-Morena Zone’s and West Meguma’s detrital rocks strongly suggest a similar paleogeographic setting (but diachronic) for both terrains from the Ediacaran to Lower Ordovician times relative to the North African blocks.
- Strategic Participation of Active Citizen Energy Communities in Spot Electricity Markets Using Hybrid Forecast MethodologiesPublication . Algarvio, HugoABSTRACT: The increasing penetrations of distributed renewable generation lead to the need for Citizen Energy Communities. Citizen Energy Communities may be able to be active market players and solve local imbalances. The liberalization of the electricity sector brought wholesale and retail competition as a natural evolution of electricity markets. In retail competition, retailers and communities compete to sign bilateral contracts with consumers. In wholesale competition, producers, retailers and communities can submit bids to spot markets, where the prices are volatile or sign bilateral contracts, to hedge against spot price volatility. To participate in those markets, communities have to rely on risky consumption forecasts, hours ahead of real-time operation. So, as Balance Responsible Parties they may pay penalties for their real-time imbalances. This paper proposes and tests a new strategic bidding process in spot markets for communities of consumers. The strategic bidding process is composed of a forced forecast methodology for day-ahead and short-run trends for intraday forecasts of consumption. This paper also presents a case study where energy communities submit bids to spot markets to satisfy their members using the strategic bidding process. The results show that bidding at short-term markets leads to lower forecast errors than to long and medium-term markets. Better forecast accuracy leads to higher fulfillment of the community programmed dispatch, resulting in lower imbalances and control reserve needs for the power system balance. Furthermore, by being active market players, energy communities may save around 35% in their electrical energy costs when comparing with retail tariffs.
- Effective fractionation of microalgae biomass as an initial step for its utilization as a bioenergy feedstockPublication . Martins, Pedro L.; Reis, Alberto; Duarte, Luís C.; Carvalheiro, FlorbelaABSTRACT: Scenedesmus obliquus, a biotechnologically relevant microalgae, was grown in 70 L vertical photobioreactors using non-supplemented secondary brewery wastewater as a culture medium. Upon collection, by mechanical means, the cells were subjected to hydrothermal (autohydrolysis) and dilute acid hydrolysis (0.5 % sulfuric acid) pre-treatments carried out using pressure micro-reactors under isothermal conditions up to 300 min. Both processes enabled a high recovery of soluble sugars (similar to 50 %) that were, in a great majority, present in the added-value oligomeric form (92 % and 90.5 % for autohydrolysis and dilute acid hydrolysis, respectively). Protein solubilization also presented relevant yields (35 % removal), with dilute acid hydrolysis allowing both higher oligosaccharides and protein productivities at a milder temperature. As compared to the current whole microalgae biomass-based upgrade strategies, the use of these mild processes is extremely promising, as they will enable the future co-production of added-value oligosaccharides, and protein, which can be relevant co-products of a biofuels-based biorefinery.
- Direct lipid and carotenoid extraction from Rhodosporidium toruloides broth culture after high pressure homogenization cell disruption: Strategies, methodologies, and yieldsPublication . Dias, Carla; Nobre, B. P.; Santos, J. A. L.; Silva, Teresa Lopes da; Reis, AlbertoABSTRACT: Biodiesel produced from oleaginous microorganisms is considered an appealing option since oleaginous yeasts and microalgae can accumulate between 20 % and 80 % lipids of their dry cell weight. However, it is still not economically sustainable since production costs are still high. This work developed a new mild protocol using hexane or sunflower oil as extraction solvents to simultaneously extract lipids and carotenoids from Rhodosporidium toruloides biomass directly from the broth culture without using any harvesting technique after performing high pressure homogenization to disrupt the yeast cells. The highest results were obtained for the hexane extractions attaining 55.9 % of total lipids (w/w) and 111.5 mu g g-1 (eq. torulene) of carotenoids, which are higher values than the ones obtained using lipid extraction traditional methods. The process here presented is an easy, simple, inexpensive and environmentally friendly methodology which involves the simultaneous extraction of carotenoids and lipids directly from R. toruloides broth culture which has never been reported before and can greatly improve the economics of the biodiesel production process.
- Enhancing wind power forecast accuracy using the weather research and forecasting numerical model-based features and artificial neuronal networksPublication . Couto, António; Estanqueiro, AnaABSTRACT: Forecasting with accuracy the quantity of energy produced by wind power plants is crucial to enabling its optimal integration into power systems and electricity markets. Despite the remarkable improvements in the wind forecasting systems in recent years, large errors can still be observed, especially for longer time horizons. This work focuses on identifying new numerical weather prediction (NWP)-based features aiming to improve the overall quality of wind power forecasts. The methodology also incorporates a sequential forward feature selection algorithm. This algorithm was designed to select iteratively the meteorological features which minimize the wind forecast errors. The methodology was applied separately to seven wind parks in Portugal with different climate characteristics. The proposed approach allowed a reduction between 13% and 37% in the root mean square errors of wind power forecasts, compared with a baseline scenario. While the meteorological features identified for each wind park showed similarities within regions with analogous wind power generation profiles, each wind park required specific meteorological parameters as input data to obtain the best performance. Thus, the results show to be crucial to select the most relevant features of a specific site to maximize the accuracy of a wind power forecast.