Prospecção de recursos hidrominerais e geotérmicos na Orla Ocidental Portuguesa: os casos das Termas dos Cucos e de Monte Real

A cobertura sedimentar da região Oeste portuguesa é constituída por uma série possante de sedimentos com uma variedade de fácies com idades compreendidas entre o Triásico Superior e o actual. Estes sedimentos foram depositados numa bacia alongada com direcção NNE‐SSW. A tectónica desta cobertura sedimentar é condicionada pelas falhas tardi‐Variscas que afectaram o substrato e pelo complexo evaporítico depositado na base das séries sedimentares. Séries evaporíticas espessas de idade Hetangiana formaram numerosas estruturas diapíricas. Na região Oeste de Portugal existem diversas nascentes minerais e termais usadas para hidroterapia. Esta tese tem por objectivo estudar as concessões hidrominerais das Termas dos Cucos e das Termas de Monte Real (Portugal Central), bem como as suas áreas envolventes. Estas actividades hidroterapêuticas são muito relevantes em termos sócio‐económicos para os concelhos de Torres Vedras e Leiria. Os estudos contemplados nesta tese (que incluíram trabalho de campo no domínio da geotectónica, geomorfologia e hidrogeologia) permitiram delinear modelos hidrogeológicos conceptuais, apoiados, ainda, pela re‐interpretação de estudos geofísicos e hidrogeológicos prévios. A caracterização destas áreas foi suportada por inventários hidrogeológicos, tendo sido determinante para o projecto dos furos de captação, incluindo localização e profundidade. Todos os dados compilados foram representados cartograficamente numa base de Sistemas de Informação Geográfica (SIG).

Conditional probability applied to the definition of limestone geochemical facies: A new Methodological Approach

A new method, based on linear correlation and phase diagrams was successfully developed for processes like the sedimentary process, where the deposition phase can have different time duration - represented by repeated values in a series - and where the erosion can play an important rule deleting values of a series. The sampling process itself can be the cause of repeated values - large strata twice sampled - or deleted values: tiny strata fitted between two consecutive samples. What we developed was a mathematical procedure which, based upon the depth chemical composition evolution, allows the establishment of frontiers as well as the periodicity of different sedimentary environments. The basic tool isn't more than a linear correlation analysis which allow us to detect the existence of eventual evolution rules, connected with cyclical phenomena within time series (considering the space assimilated to time), with the final objective of prevision. A very interesting discovery was the phenomenon of repeated sliding windows that represent quasi-cycles of a series of quasi-periods. An accurate forecast can be obtained if we are inside a quasi-cycle (it is possible to predict the other elements of the cycle with the probability related with the number of repeated and deleted points). We deal with an innovator methodology, reason why it's efficiency is being tested in some case studies, with remarkable results that shows it's efficacy. Keywords: sedimentary environments, sequence stratigraphy, data analysis, time-series, conditional probability.

RuSe Electrocatalysts and Single Wall Carbon Nanohorns Supports for the Oxygen Reduction Reaction

Selenium modified ruthenium electrocatalysts supported on carbon black were synthesized using NaBH4 reduction of the metal precursor. Prepared Ru/C electrocatalysts showed high dispersion and very small averaged particle size. These Ru/C electrocatalysts were subsequently modified with Se following two procedures: (a) preformed Ru/carbon catalyst was mixed with SeO2 in xylene and reduced in H2 and (b) Ru metal precursor was mixed with SeO2 followed by reduction with NaBH4. The XRD patterns indicate that a pyrite-type structure was obtained at higher annealing temperatures, regardless of the Ru:Se molar ratio used in the preparation step. A pyrite-type structure also emerged in samples that were not calcined; however, in this case, the pyrite-type structure was only prominent for samples with higher Ru:Se ratios. The characterization of the RuSe/C electrocatalysts suggested that the Se in noncalcined samples was present mainly as an amorphous skin. Preliminary study of activity toward oxygen reduction reaction (ORR) using electrocatalysts with a Ru:Se ratio of 1:0.7 indicated that annealing after modification with Se had a detrimental effect on their activity. This result could be related to the increased particle size of crystalline RuSe2 in heat-treated samples. Higher activity of not annealed RuSe/C catalysts could also be a result of the structure containing amorphous Se skin on the Ru crystal. The electrode obtained using not calcined RuSe showed a very promising performance with a slightly lower activity and higher overpotential in comparison with a commercial Pt/C electrode. Single wall carbon nanohorns (SWNH) were considered for application as ORR electrocatalysts' supports. The characterization of SWNH was carried out regarding their tolerance toward strong catalyzed corrosion conditions. Tests indicated that SWNH have a three times higher electrochemical surface area (ESA) loss than carbon black or Pt commercial electrodes.

Assessment of groundwater contamination in an agricultural peri-urban area (NW Portugal): an integrated approach

The excessive use of pesticides and fertilisers in agriculture has generated a decrease in groundwater and surface water quality in many regions of the EU, constituting a hazard for human health and the environment. Besides, on-site sewage disposal is an important source of groundwater contamination in urban and peri-urban areas. The assessment of groundwater vulnerability to contamination is an important tool to fulfil the demands of EU Directives. The purpose of this study is to assess the groundwater vulnerability to contamination related mainly to agricultural activities in a peri-urban area (Vila do Conde, NW Portugal). The hydrogeological framework is characterised mainly by fissured granitic basement and sedimentary cover. Water samples were collected and analysed for temperature, pH, electrical conductivity, chloride, phosphate, nitrate and nitrite. An evaluation of groundwater vulnerability to contamination was applied (GOD-S, Pesticide DRASTIC-Fm, SINTACS and SI) and the potential nitrate contamination risk was assessed, both on a hydrogeological GIS-based mapping. A principal component analysis was performed to characterised patterns of relationship among groundwater contamination, vulnerability, and the hydrogeological setting assessed. Levels of nitrate above legislation limits were detected in 75 % of the samples analysed. Alluvia units showed the highest nitrate concentrations and also the highest vulnerability and risk. Nitrate contamination is a serious problem affecting groundwater, particularly shallow aquifers, especially due to agriculture activities, livestock and cesspools. GIS-based cartography provided an accurate way to improve knowledge on water circulation models and global functioning of local aquifer systems. Finally, this study highlights the adequacy of an integrated approach, combining hydrogeochemical data, vulnerability assessments and multivariate analysis, to understand groundwater processes in peri-urban areas.

Using neural networks and support vector regression to relate marchetti dilatometer test parameters and maximum shear modulus

In the last two decades, small strain shear modulus became one of the most important geotechnical parameters to characterize soil stiffness. Finite element analysis have shown that in-situ stiffness of soils and rocks is much higher than what was previously thought and that stress-strain behaviour of these materials is non-linear in most cases with small strain levels, especially in the ground around retaining walls, foundations and tunnels, typically in the order of 10−2 to 10−4 of strain. Although the best approach to estimate shear modulus seems to be based in measuring seismic wave velocities, deriving the parameter through correlations with in-situ tests is usually considered very useful for design practice.The use of Neural Networks for modeling systems has been widespread, in particular within areas where the great amount of available data and the complexity of the systems keeps the problem very unfriendly to treat following traditional data analysis methodologies. In this work, the use of Neural Networks and Support Vector Regression is proposed to estimate small strain shear modulus for sedimentary soils from the basic or intermediate parameters derived from Marchetti Dilatometer Test. The results are discussed and compared with some of the most common available methodologies for this evaluation.

Using neural networks and support vector regression to relate marchetti dilatometer test parameters and maximum shear modulus

In the last two decades, small strain shear modulus became one of the most important geotechnical parameters to characterize soil stiffness. Finite element analysis have shown that in-situ stiffness of soils and rocks is much higher than what was previously thought and that stress-strain behaviour of these materials is non-linear in most cases with small strain levels, especially in the ground around retaining walls, foundations and tunnels, typically in the order of 10−2 to 10−4 of strain. Although the best approach to estimate shear modulus seems to be based in measuring seismic wave velocities, deriving the parameter through correlations with in-situ tests is usually considered very useful for design practice.The use of Neural Networks for modeling systems has been widespread, in particular within areas where the great amount of available data and the complexity of the systems keeps the problem very unfriendly to treat following traditional data analysis methodologies. In this work, the use of Neural Networks and Support Vector Regression is proposed to estimate small strain shear modulus for sedimentary soils from the basic or intermediate parameters derived from Marchetti Dilatometer Test. The results are discussed and compared with some of the most common available methodologies for this evaluation.

Ocupação da orla costeira, sua morfologia e riscos inerentes. Caso de Estudo Caminha-Espinho

Neste relatório é descrito o estágio curricular efetuado na Agência Portuguesa do Ambiente – Administração da Região Hidrográfica do Norte, na Divisão de Recursos Hídricos do Litoral no âmbito da unidade curricular de Dissertação/Projeto/Estágio do Mestrado em Engenharia Civil – ramo de Infraestruturas do Instituto Superior de Engenharia do Porto. Durante o estágio pretendeu-se estudar a ocupação e ordenamento da orla costeira Caminha-Espinho, estudar fenómenos de erosão/acreção de sedimentos, bem como analisar riscos a ela inerentes. Foram desenvolvidos três trabalhos distintos. No primeiro, identificaram-se e caracterizaram-se as ocupações em Domínio Público Marítimo. De seguida, pretendeu-se quantificar balanços sedimentares desta orla, utilizando como referência dados dos anos 2001 e 2011. Por fim, abordaram-se os riscos associados à orla costeira, soluções implementadas e intervenções efetuadas pela APA sobre algumas zonas de risco. Cada trabalho levou à produção de um anexo respetivo que apresenta com maior detalhe os resultados obtidos.

Gestão de Zonas Costeiras: caso de estudo Caminha-Espinho

O presente relatório descreve o Estágio Curricular desenvolvido na instituição pública Agência Portuguesa do Ambiente (APA) I.P./ Administração da Região Hidrográfica do Norte (ARHN), na Divisão dos Recursos Hídricos do Litoral (DRHL) no Porto, no âmbito do Mestrado em Engenharia Civil, ramo de Infraestruturas, do Instituto Superior de Engenharia do Porto (ISEP). Os principais objetivos do Estágio prendem-se com a gestão de zonas costeiras, particularizando-se o caso na orla costeira Caminha-Espinho. Dá-se especial enfoque ao estudo da erosão costeira, suas consequências e soluções que a possam minimizar. Este estudo divide-se em três trabalhos principais. O primeiro identifica e caracteriza as ocupações situadas no Domínio Público Marítimo (DPM), no troço de costa em estudo. No segundo, estima-se o balanço sedimentar ocorrido durante uma década com recurso a informação geográfica (altimétrica) de 2001 e 2011. Por fim, o terceiro trabalho apresenta algumas intervenções de defesa costeira, que foram possíveis de visitar durante a sua fase de execução. As principais ferramentas utilizadas para este estudo foram softwares de Sistemas de Informação Geográfica (SIG), como o ArcGis ou o QGIS. Estes três trabalhos encontram-se em anexo a este relatório.