Browsing by Issue Date, starting with "2021-07"
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- Nuevos datos litoestratigráficos y tectónicos en el borde sur de la Zona Centro Ibérica (Serra de S. Mamede Portugal)Publication . Ferreira, Paulo; Romão, José; Dias, R.; Ribeiro, A.RESUMEN: La revisión de la cartografía geológica en la región de Portalegre-Serra de S. Mamede reconoció una sucesión litoestratigráfica desde el Neoproterozoico hasta el Carbonífero inferior con características muy similares a aquellas ya iden tificadas en la sinforme Amêndoa-Carvoeiro. Las diferencias entre las dos sucesiones ocurren en las partes superior e inferior; se identificaron unidades del carbonífero inferior (Viseense) y la ausencia del Grupo Vale do Grou (Cámbrico superior?) en el sinforme de S. Mamede. El trabajo realizado mostró una transición tectónica de régimen de aplastamiento por cizalla pura, en la zona axial de la ZOM y en el límite de la ZOM/ZCI, pasando a cizallamiento oblicuo, marcado por cabalgamiento con techo hacia NE y cizalla miento izquierdo, en la ZCI (Portalegre). En el interior de la ZCI el régimen se caracteriza por aplastamiento puro (v.g. de S. Mamede). En la parte central del sinforme de S. Mamede se identificaron cabalgamientos, denominados Soverete y Monta recos, ambos caracterizados por el transporte de metasedimentos hacia NE y generados en los primeros episodios de la fase varisca D1. El primero coloca metasedimentos, localmente con fósiles, del Ordovícico superior sobre estratos de cuarcita del devónico inferior, mientras que el otro es responsable del transporte de litologías silúricas esquistosas, a veces carbonosas, sobre las mismas cuarcitas. Los datos estructurales obtenidos son parte de eventos de deformación durante la orogenia varisca, teniendo en cuenta el modelo de estructura en flor ya descrita en esta región.
- Biostimulant and biopesticide potential of microalgae growing in piggery wastewaterPublication . Ferreira, Alice; Melkonyan, Lusine; Carapinha, Sofia; Ribeiro, Belina; Figueiredo, Daniel; Avetisova, Gayane; Gouveia, LuisaABSTRACT: Pig farming generates highly polluting wastewaters which entail serious environmental issues when not adequately managed. Microalgae systems can be promising for cost, energy and environment-efficient treatment of piggery wastewater (PWW). Aside from clean water, the produced biomass can be used as biostimulants and biopesticides contributing to a more sustainable agriculture. Three microalgae (Tetradesmus obliquus, Chlorella protothecoides, Chlorella vulgaris) and one cyanobacterium (Synechocystis sp.) were selected after a preliminary screening in diluted wastewater (1:20) to treat PWW. The nutrient removals were 62-79% for COD (chemical oxygen demand), 84-92% for TKN (total Kjeldahl nitrogen), 79-92% for NH4+ and over 96% for PO43−. T. obliquus and C. protothecoides were the most efficient ones. After treating PWW, the produced biomass, at 0.5 g L−1, was assessed as a biostimulant for seed germination, root/shoot growth, and pigment content for tomato, watercress, cucumber, soybean, wheat, and barley seeds. We observed an overall increase on germination index (GI) of microalgae-treated seeds, owing to the development of longer roots, especially in T. obliquus and C. vulgaris treatments. The microalgae treatments were especially effective in cucumber seeds (75-138% GI increase). The biopesticide activity against Fusarium oxysporum was also evaluated at 1, 2.5 and 5 g L−1 of microalgae culture. Except for Synechocystis sp., all the microalgae tested inhibited the fungus growth, with T. obliquus and C. vulgaris achieving inhibitions above 40% for all concentrations.
- The role of heterotrophic microalgae in waste conversion to biofuels and bioproductsPublication . Silva, Teresa Lopes da; Moniz, Patricia; Silva, Carla; Reis, AlbertoABSTRACT: In the last few decades, microalgae have attracted attention from the scientific community worldwide, being considered a promising feedstock for renewable energy production, as well as for a wide range of high value-added products such as pigments and poly-unsaturated fatty acids for pharmaceutical, nutraceutical, food, and cosmetic markets. Despite the investments in microalgae biotechnology to date, the major obstacle to its wide commercialization is the high cost of microalgal biomass production and expensive product extraction steps. One way to reduce the microalgae production costs is the use of low-cost feedstock for microalgae production. Some wastes contain organic and inorganic components that may serve as nutrients for algal growth, decreasing the culture media cost and, thus, the overall process costs. Most of the research studies on microalgae waste treatment use autotrophic and mixotrophic microalgae growth. Research on heterotrophic microalgae to treat wastes is still scarce, although this cultivation mode shows several benefits over the others, such as higher organic carbon load tolerance, intracellular products production, and stability in production all year round, regardless of the location and climate. In this review article, the use of heterotrophic microalgae to simultaneously treat wastes and produce high value-added bioproducts and biofuels will be discussed, critically analyzing the most recent research done in this area so far and envisioning the use of this approach to a commercial scale in the near future.
- Study of potentially toxic elements uptake into organs of Quercus spp. from copper deposits in Slovakia, Italy and PortugalPublication . Andráš, Peter; Midula, Pavol; Milovská, Stanislava; Matos, João Xavier; Kupka, Jiří; Buccheri, Giuseppe; Turisová, IngridABSTRACT: The article is focused on the application of Energy dispersive micro X-ray fuorescence spectroscopy as a specifc method to determine the contents of potentially toxic elements and its spread in plant tissues. As a model species, Quercus spp. were selected. In order to compare the obtained results with previous research, four well-described abandoned Cu-deposits were selected for sampling: Ľubietová (Slovakia), Libiola and Caporciano (Italy), and São Domingos (Portugal). The results of micro X-ray fuorescence spectrometry confrm the irregular contamination of Quercus spp. by potentially toxic elements. The level of contamination is the highest predominantly in the root cortex, where is also the highest Ca contents (with exception of São Domingos). At Ľubietová and Caporciano, high Ni content was described in branches cortex, in branches mesoderm also Fe, Cu and Zn. At the same time, the inhibition infuence of Ca was also confrmed regarding the input of these elements into plants.
- Proyecto GEO_FPI, cartografía de la Zona Surportuguesa (ZSP). Datos preliminares de un estudio geocronológico U-PbPublication . Díez-Montes, Alejandro; Matos, João Xavier; Valverde-Vaquero, Pablo; Solá, A. Rita; Beranoaguirre, Aratz; Albardeiro, Luis; Salgueiro, Rute; Morais, Igor; Montero, P.; López, M. T.RESUMEN: La ZSP es la unidad geotectónica más al suroeste del Orógeno Varisco y se consideran los siguientes dominios: Pulo do Lobo (Frasniense inferior y Fameniense superior), Faja Pirítica Ibérica (Givetiense-Viseense superior), Grupo Flysch Baixo Alen tejo (Viseense superior-Moscoviense superior) y Grupo Suroeste (Estruniense-Bashkiriense medio). En el proyecto GEO_FPI se ha prestado especial atención a la Faja Pirítica Ibérica, ya que es una de las provincias metalogenéticas más importantes del mundo, con depósitos de sulfuros masivos (VHMS) e importantes recursos de Cu, Zn, Pb, Ag, Au, Sn, In, Se, Ge. Se ha realizado un trabajo de campo en común en la región fronteriza de España y Portugal para permitir una mejor inte gración y correlación de los datos geológicos y cartográficos. Además, se han seleccionado 31 afloramientos donde se han recogido muestras para realizar un estudio de geocronología de U-Pb en circón. Los datos de edad obtenidos son importantes para restringir las estructuras geológicas de la Faja Pirítica Ibérica que albergan la mineralización masiva de sulfuros y, por otra parte, mejoran la visión geotectónica de toda la ZSP
- Development of DLR analysis and power system models: Deliverable D3.1Publication . Algarvio, Hugo; Duque, Joaquim; Couto, AntónioABSTRACT: This deliverable presents the work developed by LNEG as part of the R&D activities of the project OPTIGRID - Methodology for the dynamic line rating analysis and optimal management of power networks. According to the plan activities of Tasks 3.1 and 3.2, the main objective of this deliverable is to integrate the mathematical model for the Dynamic Line Rating (DLR) analysis in the optimal power flow model for a generic AC power system, previously developed in LNEG. The main limiting factor for the transmission capacity of overhead lines (OHLs) is usually defined by a thermal constraint. For OHLs several effects are present, some with a positive contribution while others can lead to the potential congestion of the electrical networks. The seasonal line rating (SLR) methodology, traditionally used by the system operators to ensure that the grid does not operate over the maximum pre defined conductor temperature, determines the line’s ampacity from constant weather conditions using: 1) seasonal basis information or 2) conservative weather conditions. These conditions usually underestimate the real transmission capacity of OHLs. Thus DLR analysis allows assessing more realistic current limits for the power lines could present a method to deal with potentially congested electrical networks enabling the optimal integration of distributed renewable power generation.
- Presencia y tratamiento de la Paleontología en los contenidos curriculares de la Educación Secundaria en las leyes implementadas desde 1970 en EspañaPublication . Acedo, Abel; Fesharaki, Omid; García-Frank, AlejandraRESUMEN: El análisis de terminología explícita relacionada con la paleontología y la evolución en los currículos educativos estatales desde 1970 a 2020 refleja la escasez o incluso la ausencia de referencias, caracterizadas por un tratamiento poco homogéneo, siendo la LOMCE el marco que recoge mayor variedad de términos. Destaca la omisión de la palabra “paleontología” en todas las leyes posteriores a la Ley General de Educación (1970). Se observa un aumento de la importancia en términos relacionados con los paleoambientes o los paleoclimas, en parte acorde con la propia evolución social y legislativa que da mayor importancia a la sostenibilidad y la protección del medio natural. Finalmente, se incide en la necesidad de incluir nociones sobre la importancia de esta ciencia y dar una visión sistémica de la evolución en las asignaturas relacionadas con la Biología y la Geología en Educación Secundaria.
- U-Pb zircon SHRIMP dating of a protracted magmatic setting and its volcanic emplacementPublication . Lains Amaral, João; Solá, A. Rita; Santos, Telmo M. Bento Dos; Tassinari, Colombo C. G.; Gonçalves, JoãoA geochronological study using SHRIMP U-Pb analysis of zircon grains has been conducted to date felsic volcanic rocks hosting the six massive sulphide deposits of the giant Aljustrel mining district in the Iberian Pyrite Belt. A multiple method age calculation approach was used to validate and ponder calculated Concordia ages (emplacement and inherited), which included weighted average, probability density peak(s), Tuff Zirc and Unmix functions. This approach was particularly useful to interpret the wide continuous single U-Pb ages (320–405 Ma) recorded in the Aljustrel volcanic rocks. The volcanic pile (>250 m) that hosts the Aljustrel deposits was emplaced between 359 and 353 Ma. Upper Devonian inheritance, representing subvolcanic activity, is well-represented in the volcanic rocks of Aljustrel (373–365 Ma). Older Devonian inherited zircon ages at 405 Ma, 388 Ma and 380 Ma were retrieved, hypothetically representing deep plutonism or other melting episodes, which suggests a long-lasting (~50 Ma) magmatic activity in the Aljustrel district. Older pre-Devonian inherited ages, uppermost Silurian and early to late Cambrian, and post-emplacement ages (~330–345 Ma) were also detected, with the latter reflecting Pb loss most likely driven by the main Variscan orogenic event. Maximum ages obtained for the volcanic rocks in the different deposits open the possibility that the last pulses of volcanic activity and subsequent deposition of the massive sulphides were diachronic in the different Aljustrel sub-basins. Additionally, results imply that, contrary to previously assumed, Gavião and São João-Moinho deposits are probably not the same ore lens disrupted by tardi-Variscan faults. This opens new opportunities for mining exploration and targeting in the Aljustrel district and points out the importance of high-resolution geochronological studies in mining and brownfield areas.
- Metal-Oxide-Semiconductor devices for interface studies for perovskite technology [Resumo]Publication . Cunha, J.M.V.; Barreiros, M. Alexandra; Teixeira, J.P.; Curado, M.A.; Lopes, T.S.; Oliveira, K.; Oliveira, A.J.N.; Barbosa, J.R.S.; Vilanova, António; Brites, Maria João; Mascarenhas, João; Flandre, Denis; Silva, Ana G.; Fernandes, P.A.; Salomé, P.M.P.
- In vitro toxicity of arsenic rich waters from an abandoned gold mine in northeast PortugalPublication . Costa, Maria; Gošar, Doroteja; Pinti, Marika; Ferreira, Adelaide; Marušič, Martina BergantABSTRACT: This is a follow-up study of physicochemical water monitoring data from the abandoned Freixeda gold mine in Portugal, where arsenic (As) has remained above drinking water and irrigation limits over the years. The main objective of the current work was to investigate the toxicological potential of As-containing water on human cell line as an indicator of a potential health risk to humans. Six water samples collected in February 2018 were analysed for arsenic, major anions, cations and trace elements. Toxicity experiments were carried out on the human gastrointestinal cell line Caco-2 with five water samples containing As above 10 μg L−1. The results show that groundwater contains higher amounts of dissolved minerals than surface water, particularly with higher concentrations of SO42−, Fe and HCO3− and also higher As(III), reaching 336 μg L−1 (As(T) = 607 μg L−1). In surface waters As concentration decreased and reached 150 μg L−1, mainly as As(V). Metabolic activity was generally lower in Caco-2 cells exposed to As-containing water samples compared to pure As(III) solution, adapted to As concentrations, while production of reactive oxygen species (ROS) was higher. Short-term exposure to As-contaminated water samples also resulted in increased genotoxicity. This study suggests that mixture of As with various chemical elements in water may have a synergistic effect in promoting cytotoxicity. It is likely that prolonged exposure, as is common in areas with contaminated water, would have even more harmful effects.