Browsing by Issue Date, starting with "2022-03"
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- Dados Copernicus na caracterização e monitorização de recursos geológicos em Portugal [Resumo]Publication . Quental, Lídia; Gonçalves, Pedro; de Oliveira, Daniel Pipa Soares; Patinha, Pedro; Dias, Ruben Pereira
- Usos de água concorrentes para a agricultura e geração de eletricidade: quantificação dos impactos das alterações climáticas no setor eletroprodutor Português [Comunicação oral]Publication . Simoes, Sofia; Brás, Teresa; Amorim, Filipa; Fortes, PatriciaRESUMO: Neste webinar apresentamos os resultados de um estudo do LNEG e do CENSE – NOVA para 2050 focando o impacto combinado das alterações climáticas segundo o Representative Concentration Pathway 8.5 e a variação expectável na utilização de água para agricultura tanto em Portugal como em Espanha. A análise estuda as bacias do Douro e Tejo e o impacto que se poderá sentir no sistema eletroprodutor nacional como um todo.
- Relatório palinológico - Corte Via Vai (Formação Almoster) : Rio Maior, PortugalPublication . Mendes, Márcia; Pereira, Zélia
- Dados Copernicus na caracterização e monitorização de recursos geológicos em Portugal [Poster]Publication . Quental, Lídia; Gonçalves, Pedro; de Oliveira, Daniel Pipa Soares; Patinha, Pedro; Dias, Ruben Pereira
- The age of the first pulse of continental rifting associated with the breakup of Pangea in Southwest Iberia: new palynological evidencePublication . Vilas Boas, Margarida; Paterson, Niall W.; Pereira, Zélia; Fernandes, Paulo; Cirilli, SimonettaABSTRACT: In this work, we report the first palynological age for the base strata of the Silves Sandstones of the Silves Group in the Algarve Basin, located in Southern Portugal. The group is the oldest sedimentary unit of the Algarve Basin and was deposited unconformably over late Pennsylvanian turbidites of the Mira Formation, which were folded and faulted during the Variscan Orogeny. The Silves Group comprises a detrital red bed succession, representing the earliest phase of sedimentation associated with the initial rifting of Pangaea. Macrofossils are rare, occurring predominantly in the top layers of this group, and do not accurately constrain the age of the entire group's deposition. From an outcrop exposed in the central Algarve, a grey mudstone bed positioned 2.5 m above the Variscan unconformity plane yielded palynomorphs that date the beginning of sedimentation in this basin to the early Carnian age (Late Triassic). The moderately well preserved and low-diversity palynological association comprises Aulisporites astigmosus, Enzonalasporites densus, Ovalipollis pseudoalatus, Samaropollenites speciosus, Tulesporites briscoensis and Vallasporites ignacii, among others, and is indicative of an early Carnian age.
- D-Lactic acid production from Cistus ladanifer residues: Co-fermentation of pentoses and hexoses by Escherichia coli JU15Publication . Alves Ferreira Caturra, Júnia Aparecida; Carvalheiro, Florbela; Duarte, Luís C.; Ferreira, Ana R. P.; Martinez, Alfredo; Pereira, Helena; Fernandes, M. C.ABSTRACT: n this study, glucan-rich solids, and xylose-rich hydrolysates obtained from Cistus ladanifer distillery residues (CLR) were used for D-lactic acid (D-LA) production by the D-lactogenic Escherichia coli strain JU15. Firstly, hemicellulosic hydrolysates obtained by the autohydrolysis process were submitted to dilute sulfuric acid catalysed post-hydrolysis. The influence of operational conditions on oligosaccharides hydrolysis was assessed by the combined severity parameter (CS) in the range of 1.1-2.3. The optimum post-hydrolysis conditions were found for CS of 1.6 (300 mM H2SO4, 15 min, 121 degrees C). Subsequent detoxification procedures on post hydrolysed liquors were carried out, where 9.1% (w/v) powdered activated charcoal enabled a full removal of furfural, 5-hydroxymethylfurfural (HMF), and phenolic compounds together with a reduction of acetic acid (37%), and formic acid (27%). Diverse fermentation modes using detoxified and non-detoxified hydrolysates, as well using previously NaOH delignified glucan-rich solids alone (SHF or SSF) or together with pentoses liquors (SSCF) (5% loading) were performed. For all the tested conditions, both hemicellulose-and cellulose-derived sugars can be efficiently used as the carbon source to produce D-lactic acid by E. coli JU15 with a D-LA yield always surpassing 92 g(D-LA)/100 g sugars.
- EMAPRICE: Estudo de matérias-primas críticas e economia circular em Portugal: resultados preliminares com enfoque no setor da cerâmicaPublication . Sousa Rocha, Cristina; Alexandre, JorgeRESUMO: A Agência Portuguesa do Ambiente (APA), com o apoio do Fundo Ambiental, convidou o LNEG a desenvolver um estudo sobre matérias-primas críticas (MPC) e economia circular (EC) em Portugal (eMaPriCe, 2021-2022), o qual se encontra em desenvolvimento ao abrigo de um contrato de cooperação entre as três entidades.
- A systematic review of sustainable gold extraction from raw ores using alternative leaching reagentsPublication . Sousa, Rui; Regufe, Maria João; Fiúza, António; Machado Leite, Mário; Futuro, AuroraABSTRACT: Drawing on recent experimental and commercial developments, this review reappraises potential substitute leach reagents for cyanide in the gold mining sector. In addition to extraction, the application of these reagents in the gold processing, pre-treatment and gold purification stages is explored. The main objective here is to discuss how the gold extraction process can be more sustainable, with a view to developing more greener leaching reagents.
- Hydrolates: a review on their volatiles composition, biological properties and potential usesPublication . Tavares, Cláudia; Gameiro, José A.; Roseiro, Luisa B.; Figueiredo, Ana Cristina S.ABSTRACT: An hydrolate (also known as hydrosol, floral water, aromatic water, or herbal water) is a distillate which is a product of condensation obtained after an essential oil distillation isolation procedure. Hydrolates are colloidal suspensions composed of a continuous phase, the distilled water, and a dispersed phase, the emulsion of essential oil droplets and water-soluble components, namely oxygen-containing compounds. The movement towards a circular economy, has increased the interest in the essential oil industry co-products, such as hydrolates. Hydrolates composition were mostly studied based on their volatile constituents. Moreover, they showed a diverse range of biological properties, with potential application in food, beverages, cosmetic and pharmaceutical industries, as well as in the agroforest sector. Nevertheless, the information is fragmented and dispersed under the different hydrolates designations. In the present review, the main volatile components of 362 hydrolates obtained from 194 species from 50 families is described, and the information on the corresponding essential oil main components is detailed. Additionally, the methodologies of extraction and analysis are surveyed, as well as hydrolates characteristics and traditional uses. This review also describes the different biological properties attributed to hydrolates and, according with these properties, their potential uses.
- Slow pyrolysis of cork granules under nitrogen atmosphere: by-products characterization and their potential valorizationPublication . Costa, Paula; Barreiros, M. Alexandra; Mouquinho, Ana; Silva, P. Oliveira e; Paradela, Filipe; Oliveira, Fernando Almeida CostaABSTRACT: Cork granules (Quercus suber L.) were slowly pyrolyzed at temperatures between 400-700 degrees C and under N-2 flow. While preserving its structure, some cells of the cork biochar became interconnected, allowing such carbon residue to be used as templates for manufacturing ceria redox materials. The pyrolytic char morphology was similar to that of the natural precursor. The produced cork biochar belonged to Class 1 (C > 60%) and possessed a high heating value of 32 MJ kg(-1). Other pyrolysis-derived compounds were identified and quantified through GC-FID and GC-MS analyses. The yield of gases released during cork pyrolysis was strongly dependent on the temperature used due to the thermal decomposition reactions involved in the degradation of cork. In particular, rising pyrolysis temperature from 500 to 700 T resulted in reducing the total hydrocarbon gases from 74 to 24 vol%. On the other hand, the yield of H-2 increased from 0 to 58% by increasing the pyrolysis temperature from 400 to 700 T. Due to the presence of suberin in cork, the composition and yield of bio-oil could be regulated by the pyrolysis temperature. Cork bio-oil was found to consist of long-chain hydrocarbons (from C11 to C24). The bio-oil resulting from the slow pyrolysis of cork residues is suitable as an appropriate feedstock for producing aliphatic-rich pyrolytic biofuels or as a source of olefms. Overall, the findings of this study suggest that Quercus suber L. could be a promising feedstock for biochar and biofuel production through the pyrolytic route and could contribute to the environmental and economic sustainability of the cork production industry.