Browsing by Issue Date, starting with "2022-05"
Now showing 1 - 10 of 17
Results Per Page
Sort Options
- The facial reconstruction of a Mesolithic Dog, Muge, PortugalPublication . Moraes, Cicero; Pereira, Hugo Matos; Requicha, Joao Filipe; Alves, Lara; Alexandre-Pires, Graça; Jesus, Sandra de; Guimarães, Silvia; Ginja, Catarina; Detry, Cleia; Ramalho, Miguel Magalhães; Pires, Ana ElisabeteABSTRACT: This paper presents the facial reconstruction of a Mesolithic dog whose skeleton was recovered from the Muge shell middens (Portugal) in the 19th century. We used the anatomical deformation approach based on a collection of computer tomography images as an attempt to reconstruct the Muge dog's head appearance. We faced a few challenges due to the level of bone displacement and the absence of some cranium anatomical parts, as well as accurate information on soft tissue thickness for modern dogs. This multidisciplinary study combined anatomical, veterinary, zooarchaeological, artistic and graphic aspects to allow for the facial reconstruction of the Muge dog. Albeit an approximation, it confers a recognition to this prehistoric finding.
- A new biosurfactant/bioemulsifier from Gordonia alkanivorans Strain 1B: production and characterizationPublication . Silva, Tiago; Paixão, Susana M.; Tavares, João; Gil, Catia V.; Torres, Cristiana A. V.; Freitas, Filomena; Alves, LuísABSTRACT: Biosurfactants and bioemulsifiers (BS/BE) are naturally synthesized molecules, which can be used as alternatives to traditional detergents. These molecules are commonly produced by microorganisms isolated from hydrocarbon-rich environments. Gordonia alkanivorans strain 1B was originally found in such an environment, however little was known about its abilities as a BS/BE producer. The goal of this work was to access the potential of strain 1B as a BS/BE producer and perform the initial characterization of the produced compounds. It was demonstrated that strain 1B was able to synthesize lipoglycoprotein compounds with BS/BE properties, both extracellularly and adhered to the cells, without the need for a hydrophobic inducer, producing emulsion in several different hydrophobic phases. Using a crude BS/BE powder, the critical micelle concentration was determined (CMC = 16.94 mg/L), and its capacity to reduce the surface tension to a minimum of 35.63 mN/m was demonstrated, surpassing many commercial surfactants. Moreover, after dialysis, emulsification assays revealed an activity similar to that of Triton X-100 in almond and sunflower oils. In benzene, the E-24 value attained was 83.45%, which is 30% greater than that of the commercial alternative. The results obtained highlight for the presence of promising novel BS/BE produced by strain 1B.
- Atlas Nacional do H2 Verde SustentávelPublication . Ponce Leao, Maria Teresa; Simoes, Sofia; Simões, Teresa; Quental, Lídia; Catarino, Justina; Amorim, Filipa; Brás, Teresa; Patinha, Pedro; Lopes, Tiago; Rodrigues, Carlos; Machado, Susana; Rangel, C. M.; Gírio, Francisco; Picado, AnaRESUMO: O "Atlas Nacional do H2 Verde Sustentável" tem como objetivo apoiar o processo de decisão quanto à localização de projetos de produção de hidrogénio verde no território de Portugal continental. O Atlas foi desenvolvido pelo LNEG em colaboração com várias entidades públicas e privadas nacionais. De uma forma mais geral, apoia à a transição para um país neutro em carbono, desenvolvendo uma economia de baixo carbono, liderando em inovação e desenvolvimento tecnológico.
- Agent-based retail competition and portfolio optimization in liberalized electricity markets: A study involving real-world consumersPublication . Algarvio, Hugo; Lopes, FernandoABSTRACT: The liberalization of energy markets brought full competition to the electric power industry. In the wholesale sector, producers and retailers submit bids to day-ahead markets, where prices are uncertain, or alternatively, they sign bilateral contracts to hedge against pool price volatility. In the retail sector, retailers compete to sign bilateral contracts with end-use customers. Typically, such contracts are subject to a high-risk premium—that is, retailers request a high premium to consumers to cover their potential risk of trading energy in wholesale markets. Accordingly, consumers pay a price for energy typically higher than the wholesale market price. This article addresses the optimization of the portfolios of retailers, which are composed of end-use customers. To this end, it makes use of a risk-return optimization model based on the Markowitz theory. The article presents a simulation-based study conducted with the help of the MATREM system, involving 6 retailer agents, with different risk preferences, and 312 real-world consumers. The retailers select a pricing strategy and compute a tariff to offer to target consumers, optimize their portfolio of consumers using data from the Iberian market, sign bilateral contracts with consumers, and compute their target return during contract duration. The results support the conclusion that retail markets are more favourable to risk-seeking retailers, since substantial variations in return lead to small variations in risk. However, for a given target return, risk-averse retailers consider lower risk portfolios, meaning that they may obtain higher returns in both favourable and unfavourable situations.
- C-E (curtailment - Energy share) map: An objective and quantitative measure to evaluate wind and solar curtailmentPublication . Yasuda, Yoh; Bird, Lori; Carlini, Enrico Maria; Eriksen, Peter Børre; Estanqueiro, Ana; Flynn, Damian; Fraile, Daniel; Lázaro, Emilio Gómez; Martín-Martínez, Sergio; Hayashi, Daisuke; Holttinen, Hannele; Lew, Debra; McCann, John; Menemenlis, Nickie; Miranda, Raul; Orths, Antje; Smith, J. Charles; Taibi, Emanuele; Vrana, Til KristianABSTRACT: s the share of VRE (variable renewable energy) has grown rapidly, curtailment issues have arisen worldwide. This paper evaluates and compares curtailment situations in selected countries using an objective and quantitative evaluation tool named the "C-E map " (curtailment-energy share map). The C-E map is a correlation map between curtailment ratios that mean curtailed wind (or solar) energy per available energy and energy shares of wind (or solar). The C-E map can draw a historical trend curve in a given country/area, as an at-a-glance tool to enable historical and/or international comparison. The C-E map also can classify the given countries/areas into several categories, according to the current levels of curtailment ratio and historical trends. The C-E map helps institutional and objective understanding of curtailment for non-experts including policy makers.
- A associação fossilífera do Devónico da localidade de Serra (Rates, Noroeste de Portugal) revisitada: contributo para a valorização geopatrimonial de uma área clássica do Paleozoico IbéricoPublication . Domingos, Rúben; Correia, Pedro; Legoinha, Paulo; M. Callapez, PedroRESUMO: Neste trabalho efetuou-se o estudo de um sítio paleontológico no Devónico de Rates (Noroeste de Portugal), contendo uma fauna marinha composta por invertebrados típicos deste sistema. O afloramento encontra se 35 km a norte do Porto, inserido no prolongamento de unidades paleozoicas do Anticlinal de Valongo. Os níveis fossilíferos correspondem a xistos argilosos amarelos do “Membro Superior” da “Formação Telheiras” e apresentam uma associação paleontológica rica e diversificada, formada por corais, briozoários, braquiópodes, tentaculites, crinoides e trilobites, correlativa do Pragiano–Emsiano (Devónico inferior). Destaca-se o género Pleurodictyum, aqui representado por espécimes morfologicamente distintos da espécie-tipo P. problematicum, a qual tem vindo a ser identificada frequentemente em estudos anteriores. Com a inacessibilidade da maioria das jazidas clássicas do Devónico Inferior desta região, esta descoberta e revisão do conhecimento pretende valorizar o património geológico de uma das áreas clássicas do Paleozoico Ibérico, complementando o do Parque das Serras do Porto.
- Evaluation of the biocontrol potential of a commercial yeast starter against fuel-ethanol fermentation contaminantsPublication . Branco, Patricia; Diniz, Mário; Albergaria, HelenaABSTRACT: Lactic acid bacteria (LAB) and Brettanomyces bruxellensis are the main contaminants of bioethanol fermentations. Those contaminations affect Saccharomyces cerevisiae performance and reduce ethanol yields and productivity, leading to important economic losses. Currently, chemical treatments such as acid washing and/or antibiotics are used to control those contaminants. However, these control measures carry environmental risks, and more environmentally friendly methods are required. Several S. cerevisiae wine strains were found to secrete antimicrobial peptides (AMPs) during alcoholic fermentation that are active against LAB and B. bruxellensis strains. Thus, in the present study, we investigated if the fuel-ethanol commercial starter S. cerevisiae Ethanol Red (ER) also secretes those AMPs and evaluated its biocontrol potential by performing alcoholic fermentations with mixed-cultures of ER and B. bruxellensis strains and growth assays of LAB in ER pre-fermented supernatants. Results showed that all B. bruxellensis strains were significantly inhibited by the presence of ER, although LAB strains were less sensitive to ER fermentation metabolites. Peptides secreted by ER during alcoholic fermentation were purified by gel-filtration chromatography, and a bioactive fraction was analyzed by ELISA and mass spectrometry. Results confirmed that ER secretes the AMPs previously identified. That bioactive fraction was used to determine minimal inhibitory concentrations (MICs) against several LAB and B. bruxellensis strains. MICs of 1-2 mg/mL were found for B. bruxellensis strains and above 2 mg/mL for LAB. Our study demonstrates that the AMPs secreted by ER can be used as a natural preservative in fuel-ethanol fermentations.
- Opções de armazenamento [Comunicação oral]Publication . Simoes, SofiaRESUMO: A ALER e a AMER , em parceria com a EDM - Electricidade de Moçambique e com o apoio do GET.invest Mozambique - financiado pela União Europeia e Alemanha, e integrado no programa europeu GET.invest organizaram o evento híbrido "Armazenamento e Integração de Renováveis na Rede em Moçambique" que decorreu no dia 25 de Maio, no Indy Congress Hotel em Maputo, com transmissão online. Neste evento foi apresentado o estado atual e os desenvolvimentos futuros dos projetos de energias renováveis e da rede elétrica em Moçambique, foram debatidas as soluções de armazenamento e integração da produção de origem renovável na rede e foi discutido o quadro técnico e regulamentar existente.
- New data on the palynostratigraphy and paleoenvironments of the late Miocene (Tortonian) Quifangondo Formation in the Cabo Ledo section, Kwanza Basin, AngolaPublication . Mendes, Márcia; Lopes, Gilda; Pereira, Zélia; Rodrigues, C.; Nsungani, P.C.; Wandofusu, Heritier; Sousa, M.J. Lemos deABSTRACT: A detailed palynostratigraphic and palynofacies analysis, associated with a lithological control, was carried out on eleven outcrop samples from the Quifangondo Formation in the Cabo Ledo (Petrofina) section, Kwanza Basin, Angola. The samples yield relatively diverse and well-preserved terrestrial and marine palynomorphs. A systematic analysis of the samples enables the identification of nine spore genera and 3 species, 20 pollen genera and 13 species, and 32 dinoflagellate cyst genera and 34 species. In addition, 10 genera of other aquatic palynomorphs, such as Chlorophyceae green algae, are identified. Dinoflagellate cysts and other aquatic palynomorphs typically dominate throughout the assemblages. In this section, a combined pollen - dinoflagellate cyst zonation is used to define two palynoassociations. The first palynoassociation is middle Tortonian in age and is characterized by the presence of the pollen grain Fenestrites spinosus and the first occurrence of the dinoflagellate cyst species Selenopemphix armageddonensis. Additionally, diverse Chlorophyceae green algae dominate most of this interval samples. The second palynoassociation is assigned to the late Tortonian and is characterized by a drastic decrease in Chlorophyceae green algae, as opposed to the gonyaulacales dinoflagellate cysts. The first occurrence of the pollen grain Fenestrites longispinosus marks the transition between the palynoassociations. Lithologically, the Cabo Ledo (Petrofina) section is dominated by a claystone with an increase in the silt and carbonate components towards the upper section. The lithological data, integrated with palynostratigraphy and palynofacies, suggests that the upper part of the Quifangondo Formation was mainly deposited in an inner to middle neritic environment characterized by dysoxic conditions punctuated by periods of terrestrial inflows. Such conditions typically result from seasonal fluctuations. The age and depositional environment of the upper Quifangondo Formation inferred from this new data allows a correlation with the other Quifangondo sequences previously studied by the authors. This multi-proxy approach is important for further stratigraphic analysis with other age-controlled lithostratigraphic units in the basin. Furthermore, the improvement of paleoenvironmental and depositional models for this unit is of great importance for cross-basin correlation and future petroleum exploration plays.