35 research outputs found

    Depósitos cenozóicos de Trás-os-Montes Oriental : Caracterização tecnológica de resíduos de exploração de areeiros : Contribuição para o uso sustentável dos recursos

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    Dissertação de Mestrado em Prospecção e Avaliação de Recursos Geológicos apresentada à Faculdade de Ciências da Universidade do Port

    Estudo geoarqueológico com Georadar : aplicação aos contextos arqueológicos da Pré-História recente à Proto-História do NW de Portugal

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    Tese de doutoramento em Ciências (área de especialização de Geologia)A necessidade de caracterização das estações arqueológicas com recurso a métodos não destrutivos e não intrusivos, dá uma importância de relevo às técnicas de prospecção geofísica e em particular ao Georadar. A prospecção geofísica com Georadar é, na actualidade, uma das metodologias mais utilizadas a nível mundial para o estudo de sítios arqueológicos, possibilitando a definição da estratigrafia do subsolo e a detecção, identificação e mapeamento de estruturas arqueológicas soterradas. O presente trabalho descreve a aplicação do Georadar ao estudo de estações arqueológicas da Pré-História recente e da Proto-História do NW de Portugal, tendo por objectivos: a definição de uma metodologia prospectiva que se adeqúe aos contextos arqueológicos em questão; a definição de metodologias de aquisição de dados mais adequadas a sítios arqueológicos de ampla diacronia e de estratigrafia complexa; a definição de metodologias prospectivas que se adequam a sítios arqueológicos com estruturas pétreas e com estruturas perecíveis ou escavadas no subsolo. No âmbito desta tese foram escolhidos seis casos de estudo entre o Neolítico e o período romano, nomeadamente: dólmen da Tojeira (Póvoa de Lanhoso); área contígua aos monumentos sob tumuli de Vale de Chãos 1 e 2 (Braga); povoado/necrópole do Pego (Braga); área envolvente às gravuras rupestres de Campelo (Mondim de Basto); povoado do Crastoeiro (Mondim de Basto) e castro do Monte do Padrão (Santo Tirso). A prospecção geofísica realizada nestes sítios arqueológicos foi efectuada com o equipamento de Georadar SIR3000 da GSSI, e antena de 400 MHz. Foram aplicadas e testadas diferentes metodologias de prospecção, nomeadamente: prospecção com perfis individuais; prospecção em área pseudo 3D, com perfis adquiridos numa direcção e em direcções ortogonais, com espaçamentos de 20 cm e 50 cm entre perfis, e prospecção em área de alta resolução ou verdadeiro 3D, com 5 cm e 10 cm de espaçamento entre perfis. Após processamento, foram utilizadas e testadas várias metodologias de visualização dos dados, nomeadamente: radargramas individuais; mapas de amplitudes e imagens tridimensionais (volumes de isosuperfícies, blocos diagrama). Concluiu-se que a metodologia mais adequada à prospecção dos contextos dos sítios arqueológicos das cronologias em questão é a prospecção em área com grelhas ultra densas e/ou com perfis paralelos adquiridos em duas direcções (grelhas XY), tendo sido particularmente apropriada aos sítios arqueológicos com estruturas pétreas e/ou de elevado diacronismo. Nos sítios com estruturas subtis e/ou matérias perecíveis foi especialmente favorável a prospecção com grelhas XY. Para sítios com condições desfavoráveis (topografia irregular, presença de obstáculos, solos condutivos, etc.) o método deverá adequar-se às condições do terreno, podendo em algumas situações optar-se pelo método de perfis individuais ou pela prospecção em área com grelhas pseudo 3D. Para a visualização, a abordagem mais indicada consistiu na criação de radargramas, mapas de amplitude e imagens tridimensionais (volumes de isosuperfícies, blocos diagrama). Recomendase, em situações arqueológicas semelhantes, a análise dos radargramas, como primeiro passo na interpretação, seguida da análise de mapas de amplitudes e de imagens tridimensionais, caso se tenha realizado uma prospecção em área. A correlação dos vários tipos de imagens auxiliará uma melhor interpretação das estruturas e da estratigrafia das estações arqueológicas.The need for characterization of archaeological sites using non-destructive and non-intrusive methods, gives emphasis to the importance of geophysical techniques and in particular from Ground Penetrating Radar (GPR). This geophysical methodology is one of the most used for the study of archaeological sites, enabling the definition of subsurface site stratigraphy and the detection, identification and mapping of buried archaeological features. This thesis describes the use of GPR in the study of archaeological sites from Neolithic to Iron Age of NW Portugal, and aimed the following objectives: the definition of a prospective methodology that fits the archaeological contexts in question; the definition of data acquisition methodologies best suited to wide diachronic and stratigraphically complex archaeological sites; the definition of methodologies suited to the prospection of archaeological sites with stone structures and/or with perishable and subtle archaeological features . For this work six archaeological sites, from the Neolithic to the Roman period, were chosen as case studies, naming: the megalithic monument of Tojeira (Póvoa de Lanhoso); surrounding area from the funerary monuments under tumuli from Vale de Chãos 1 and 2 (Braga); settlement/necropolis of Pego (Braga); area surrounding the rock engraving site of Campelo (Mondim de Basto); Castro of Crastoeiro (Mondim de Basto) and Castro of Monte do Padrão (Santo Tirso). The geophysical survey was performed with GSSI SIR3000 GPR equipment, and the 400 MHz antenna. In these studies we applied and tested different prospecting methodologies, including: prospecting with individual recorded profiles; pseudo 3D detailed area survey, with profiles acquired in one direction and orthogonal directions, with spacing of 20 cm and 50 cm between profiles; high resolution detailed area survey or true 3D, with 5 cm and 10 cm spacing between profiles. After data processing several methods of data visualization were created and interpreted, including: individual radargrams; amplitudes slice maps and three-dimensional images (isosurfaces volumes, block diagrams). It was concluded that the most appropriate survey methodology to the study of these archaeological contexts is the high-resolution detailed area survey and/or detailed area survey with parallel profiles acquired in two directions (XY grids). The high-resolution survey was particularly appropriate to study of archaeological sites with stone structures and/or with high diachronism. At sites with subtle and/or perishable structures it was the detailed area survey with XY grids that presented the best results. For sites with unfavourable conditions (irregular topography, presence of obstacles, conductive soils, etc.) the survey method should adapt to the ground conditions. For data visualization, the most appropriate approach involved the generation of radargrams, amplitude slice maps and three-dimensional images (isosurfaces volumes, block diagrams). It is recommended similar archaeological contexts, the radargram analysis as interpretation first step followed by the analysis of amplitude slice maps and of three-dimensional images. The correlation of the various types of images will insure a better interpretation of the features and stratigraphy from archaeological sites

    Estimating volumes and tonnage using GPR data

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    2017 9th International Workshop on Advanced Ground Penetrating Radar, IWAGPR 2017 - ProceedingsThis work presents the use of ground-penetrating radar (GPR) data in the determination of overburden volumes and tonnage in mining context. The geophysical method of GPR was used in three distinct areas, located, inside the old Bejanca Mining Complex (parish of Queirã, Viseu District, Portugal), to determine and delineated the soil and sediment/bedrock interface. The interpretation of GPR data, and its correlation with borehole data, allowed the successful detection of this interface and the estimate of the volume and tonnage of the overburden sediments and soils. For this characterization, three-dimensional imaging methodologies were applied to create a volumetric reconstruction. The GPR system was found to be an effective tool for delineating the bedrock interface as did three-dimensional imaging methodologies in calculating the volume and tonnage for each study area. It provides not only a detailed view of the subsurface but allows the information to be gathered quickly and easily. It can also help companies revise volume and tonnage calculations and help them estimate the volume of potential new deposits as well as providing a greater financial control. Furthermore, it can be used to plan and develop prospective areas with little environmental impact.(undefined)info:eu-repo/semantics/publishedVersio

    Hydrogeochemistry of an ancient groundwater system (Sete Fontes, Braga, Northern Portugal).

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    [Excerpt] Water supply systems and morphology of ancient cities suggest a strongly constrain between urban development and water sources. The availability and location of water resources are mainly associated to a possible transport to the populations. The ancient drinking water supply system from Sete Fontes (Braga, northern Portugal) was built in the middle-eighteen century, overlaying a much older system with probable Roman origin (Martins et al., 2011), and was used as the main supply system of the city until 1913 (Vieira et al., 2016).Although with some uncertainty, the Sete Fontes area is considered by some authors (e.g., Martins et al., 2011; Martins and Ribeiro, 2012) as part of the main source area of water for the Roman city of Bracara Augusta.[...]info:eu-repo/semantics/publishedVersio

    Geothermal resources research in a granitic basement - the Braga area case study (NW Portugal)

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    Geothermal resources are increasingly being considered as a strategic alternative in energy production, especially with the latest geopolitical developments. The densely populated Braga region, in NW Portugal, is endowed with a geostructural setting that enables the existence of several thermal water occurrences, spatially associated with a deep-rooted structure – the Vigo-Régua shear zone, set in a granite context. Given the latest advances in geothermal energy production, it is possible to predict a mid- to long-term implementation of geothermal energy production in the vicinity of that deep rooted structure. Although strongly encouraging, the exploratory geophysical, geochemical and geological data are still insufficient to deliver a definitive frame of the potential energy associated with the estimated reservoirs. Ongoing work combining gravimetric, radiometric and geochemical data will provide a better understanding of the deeply concealed structures.Les ressources géothermiques sont de plus en plus considérées comme une alternative stratégique dans la production d'énergie, en particulier compte tenu du contexte géopolitique récent. La région densément peuplée de Braga, au nord-ouest du Portugal, est située dans un contexte granitique spatialement associé à une structure enracinée - la zone de cisaillement Vigo-Régua. Ce contexte géologique et structural a permis le développement de plusieurs occurrences d'eau thermale. Compte tenu des dernières avancées en matière de production d'énergie géothermique, il est possible de prévoir une mise en œuvre à moyen et long terme de la production d'énergie géothermique à proximité de cette structure profonde. Bien que fortement encourageantes, les données géophysiques, géochimiques et géologiques exploratoires sont encore insuffisantes pour fournir un cadre définitif de l'énergie potentielle associée aux réservoirs estimés. Des travaux en cours combinant des données gravimétriques, radiométriques et géochimiques permettront de mieux comprendre les structures profondément enfouies.Los recursos geotérmicos se consideran cada vez más como una alternativa estratégica en la producción de energía, especialmente con los últimos desarrollos geopolíticos. La región densamente poblada de Braga, en el noroeste de Portugal, está dotada de un entorno estructural que permite la presencia de aguas termales, asociadas espacialmente con una estructura profunda en un contexto granítico: la zona de falla Vigo-Régua. Dados los últimos avances en la producción de energía geotérmica, es posible predecir una implementación a mediano y largo plazo de la producción de energía geotérmica en las cercanías de esa estructura de raíces profundas. Aún cuando los datos geofísicos, geoquímicos y geológicos exploratorios son muy alentadores, son insuficientes para brindar un marco definitivo del potencial geotérmico asociada con los yacimientos. El trabajo en curso que integra datos gravimétricos, radiométricos y geoquímicos proporcionará una mejor comprensión de las estructuras profundas por explorar

    Let there be light...

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    “Let there be light...” is a project in the scope of the International Year of Light 2015 (IYL 2015) targeted at children of the first school grade. Basically, it comprises nine recreational - scientific workshops that last for approximately 90 minutes. Each workshop is dedicated to a different topic, namely: bioluminescence, mineral observation, the rainbow, light-shadow contrast, battery production, just to name a few, and is designed, in differ- ent approaches, by a distinct team of scientists familiar to the scientific area focused. The activity starts with the dramatized storytelling of a children’s story related to the scientific subject and performed by the team of the public library expert in this area. This moment takes place in an almost magical environment opening the door to the science topic light-related that would be focused later on. In the third part of the workshop, the children are invited to produce plastic works (e.g. drawings, constructions and models) inspired in what they have learned, and that are to be collected in a public exhibition held at the same institution at the end of the project. In the present work, besides the description of the experience, you can find the critical analysis of the activity and the evaluation of the action by all the actors involved (project team and children/teachers that attended the workshops).info:eu-repo/semantics/publishedVersio

    A Multi-Analytical study of Rock Paintings from Leandro 5 Megalithic Barrow, North-Weastern Portugal

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    The colourant composition of a northern Portugal megalithic barrow decorated with ‘solar’ motifs was studied using a multi-analytical approach, allowing the characterisa- tion of the painting techniques, pigments and binders. The red pigment was prepared with iron oxide minerals, using vegetal oils as organic additives, while the black pigment was char- coal without any organic additives or binders. The solar motif was first drawn with charcoal and subsequently painted with a red pigment.The work was supported by UID/QUI/50006/2019 with funding from FCT/MCTES through national funds. César Oliveira acknowledges Instituto de Ciências e Tecnologias Agrárias e Agro-Alimentares, Porto (ICETA), for his contract under project NORTE-01-0145-FEDER-000011. This work was also developed under the project ‘Funerary and ceremonial practices between the Neolithic and the Bronze Age approached by archaeometry’ (ARQUEOM/Project-Sept2014)

    Toxicological and anti-tumor effects of a linden extract (Tilia platyphyllos Scop.) in a HPV16-transgenic mouse model

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    Tilia platyphyllos Scop. is a popular broad-leaved tree, native to Central and Southern Europe. Hydroethanolic extracts rich in phenolic compounds obtained from T. platyphyllos Scop. have shown in vitro antioxidant, anti-inflammatory and antitumor properties. The aim of this work was to evaluate the therapeutic properties of a hydroethanolic extract obtained from T. platyphyllos in HPV16-transgenic mice. The animals were divided into eight groups according to their sex and phenotype. Four groups of female: HPV+ exposed to linden (HPV linden; n = 6), HPV+ (HPV water; n = 4), HPV- exposed to linden (WT linden; n = 5) and HPV- (WT water; n = 4) and four groups of male: HPV+ exposed to linden (HPV linden; n = 5), HPV+ (HPV water; n = 5), HPV- exposed to linden (WT linden; n = 5) and HPV- (WT water; n = 7). The linden (Tilia platyphyllos Scop.) extract was orally administered at a dose of 4.5 mg/10 mL per animal (dissolved in water) and changed daily for 33 days. The hydroethanolic extract of T. platyphyllos consisted of protocatechuic acid and (-)-epicatechin as the most abundant phenolic acid and flavonoid, respectively, and was found to be stable during the studied period. In two male groups a significant positive weight gain was observed but without association with the linden extract. Histological, biochemical, and oxidative stress analyses for the evaluation of kidney and liver damage support the hypothesis that the linden extract is safe and well-tolerated under the present experimental conditions. Skin histopathology does not demonstrate the chemopreventive effect of the linden extract against HPV16-induced lesions. The linden extract has revealed a favourable toxicological profile; however, additional studies are required to determine the chemopreventive potential of the linden extract. This journal isThis work was supported by the project IBERPHENOL, project number 0377_IBERPHENOL_6_E; Interact R&D project, operation number NORTE-01-0145-FEDER-000017, National Funds by FCT – Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020 (CITAB), and project UIDB/ CVT/00772/2020 (CECAV) and the post-graduation grant SFRH/ BD/136747/2018 and 2020.04789.BD; the authors are also grateful to FCT, Portugal and FEDER under programme PT2020 for financial support to CIMO (UIDB/00690/2020) and L. Barros acknowledges the national funding by FCT, P. I., through the institutional scientific employment program-contract. The authors would like to thank Cantinho das Aromáticas organic farmers from Vila Nova de Gaia (Portugal) for providing the samples. This work was financially supported by: Base Funding - UIDB/00511/2020 of the Laboratory for Process Engineering, Environment, Biotechnology and Energy – LEPABE - funded by national funds through the FCT/MCTES (PIDDAC).info:eu-repo/semantics/publishedVersio

    MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal

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    Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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