Multi-level optimisation models for transmission expansion planning under uncertainty

The significant integration of renewable energy sources to electricity grids poses unprecedented challenges to power systems planning. Each of these challenges is implied by a particular circumstance faced by the system planner when devising the expansion plan, which should be tailored to address the needs and objectives of the system under consideration. Within this context, this thesis is dedicated to propose methodologies to address three timely situations that may arise when planning the expansion of the grid. In the first situation, we consider the case in which the system planner must meet established renewable penetration targets while complying with multiple deterministic security criteria. Renewable targets have been largely adopted as an important mechanism to foster the decarbonization of power systems. Hence, we propose a methodology that simultaneously identifies the optimal subset of candidate assets as well as renewable sites to be developed, while introducing the concept of compound GT n-K security criteria. In the second situation, we aim to minimize the regret of the system planner under generation expansion uncertainty. In many cases, e.g. the United Kingdom, the decision on the transmission expansion plan is taken by a market player that does not determine the future generation expansion. Within this context, we propose a 5-level MILP formulation to represent the minimization of the regret of the system planner in light of a set of credible scenarios of generation expansion while enforcing n-1 security criterion. Finally, in the third situation, the objective is to inform the optimal transmission expansion plan under ambiguity in the probability distribution of RES generation output. To do so, we present a methodology capable of determining the transmission plan under deterministic security criterion while accommodating a set of different probability distributions for RES output in order to integrate ambiguity aversion.Open Acces

Assessing the balance between biodiversity conservation and coastal and estuarine management of the Sado Estuary Natural Reserve, Portugal, using BIO-SAFE

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, perfil de Engenharia EcológicaCoastal and Estuarine management is one emergent topic nowadays. Physical reconstruction and management plans are currently being executed where the major goals are flood risk reduction,ecological rehabilitation and economic development. The ecological consequences of these measures must be evaluated in a way that ensures attuning of policy goals concerning conservation of biodiversity. The estuarine systems are important for the conservation and restoration of biodiversity, since they are one of the most productive ecosystems on the planet. Recently, a novel Spreadsheet Application For Evaluation of impacts of physical reconstruction measures on BIOdiversity (i.e. BIO-SAFE) in riverine habitats has been developed (Lenders et al., 2001, De Nooij et al., 2004, De Nooij, 2006). In this study, BIO-SAFE has been adapted to the Portuguese Sado River Estuary, with the direct application on the Natural Reserve of the cited estuarine area. BIO-SAFE is a policy and legislation based assessment model that quantifies biodiversity values in riverine areas for several taxonomic groups and landscape ecological units (ecotopes) on the basis of the policy status and habitat demands of riverine characteristic species. The model uses data on presence of species and riverine landscape ecological units for different levels of spatial scale. In this study, a new version of the model was developed for the Sado Estuary Natural Reserve (RNES), called BIO-SAFE Sado. To develop the Sado version, it was necessary to adapt the three main components of the conceptual framework of BIO-SAFE. These comprise (1) a database with the relevant policy and/or legislation RNES indigenous species, (2) a specific ecotope typology for the RNES area and (3) a weighted set of policy and legislation based valuation criteria for biodiversity. In addition to these research activities, the model has been implemented in the MS Excel spreadsheet. After implementation of these three components and the programming of the different types of indices and algorithms in MS Excel, the program calculated all relevant indexes and scores. The BIOSAFE Sado model was used for two types of analysis: (a) valuations of ecotopes (potential situation)and transitions between ecotopes and (b) valuation of the actual situation. Both approaches were made on the level of species individually and taxonomic groups at two scale levels (ecotopes and levels). The taxonomic groups higher plants, birds, fish and mammals are amongst the most important taxa regarding endangered and protected biodiversity in the study area. The ecotope valuation show that the most important ecotope types regarding protected and endangered biodiversity in the RNES are the Waterlines for the aquatic ecotope types and the Dune bushes and the indigenous forestry ecotope types Pinewood and Cork oak system for the terrestrial systems. The valuation of the actual situation shows the same results for the most important taxa and ecotopes present in the RNES, which was expected since the saturation indices showed high values, indicating that most of the potential species are actually present on the area

What is the best way to invest in public FinTech companies?

The FinTech industry is becoming more attractive and is seen as a rising sector. Data shows that, in 2021, private investment vehicles, such as private equity firms, are investing more than ever in FinTech companies. The objective of this research is to determine if it is profitable to invest in FinTech stocks, and what the best strategy. Research demonstrates the profitability of different investment strategies across different markets and sectors, and yet there is no evidence and no studies applied to publicly traded FinTech companies. Based on the review of the literature on portfolio theory and market anomalies, the investment strategies chosen were value, momentum, and Combo. A small number of companies were studied and a small time period was analysed, which was due to data unviability. The investment strategies were applied, and the results were separated into two different time frames to isolate the impact of pandemic. A transaction cost analysis was done to access the portfolios’ persistence and the bootstrap method was applied to the mean excess return with the purpose of having more robust conclusions. The results indicate that, for the pre-pandemic period, investing in FinTech stocks using the momentum strategy is profitable. This strategy is even able to beat the market, producing a Sharpe ratio of 1.69. For the post-pandemic period, all the strategies employed turned out to be unprofitable and their results were quite inferior to the market.A indústria FinTech está em crescimento e é cada vez mais atrativa. Dados comprovam que, em 2021, veículos de investimento privado, como empresas de “private equity” , estão a investir mais que nunca em empresas desta indústria. Esta tese tem como objetivo determinar se é rentável investir em ações de empresas FinTech e qual é a melhor estratégia para o fazer. Existem vários estudos sobre a rentabilidade de diferentes estratégias de investimento aplicadas a inúmeros setores e mercados financeiros, contudo não há qualquer análise nem resultados sobre estas estratégias aplicadas a ações de empresas FinTech. Tendo como base a revisão de literatura sobre portefólios e anomalias de mercado, as estratégias de investimento escolhidas foram “value”, “momentum” e Combo. Devido à falta de dados, foi analisado um número reduzido de empresas e durante um curto espaço temporal. As estratégias de investimento foram aplicadas e os resultados foram analisados em dois períodos diferentes, com o propósito de isolar o impacto da pandemia. Para examinar a persistência dos portefólios, uma análise de custos de transação foi elaborada. De forma a ter resultados mais robustos, o método “Bootstrap” foi usado para o retorno médio em excesso. Os resultados indicam que, no período pré-pandémico, o investimento em ações FinTech usando a estratégia de “momentum” é rentável e acima do mercado, tendo esta estratégia um índice de Sharpe de 1.69. Para o período que inclui a pandemia, nenhuma das estratégias usadas é rentável e todas têm uma performance bastante abaixo do mercado

Biocover performance of landfill methane oxidation: Experimental results

Abstract: An experimental passive methane oxidation biocover (PMOB) was constructed within the existing final cover of the St-Nicéphore landfill. Its substrate consisted of a 0.80-m-thick mixture of sand and compost. The goal of this experiment was to evaluate the performance of the PMOB in reducing CH 4 CH4 emissions when submitted to an increasing methane load. The CH 4 CH4 load applied started with 9.3 g CH 4  m −2  d −1 9.3 g CH4 m−2 d−1 . When the site had to be closed for the winter, the CH 4 CH4 input was 820 g CH 4  m −2  d −1 820 g CH4 m−2 d−1 . Throughout the study, practically all the CH 4 CH4 input was oxidized; absolute removal rates were linearly correlated to methane loading; and the oxidation zone was established between 0.6–0.8 m. These results seem to indicate that the upper limit potential of this PMOB to oxidize CH 4 CH4 was not necessarily reached during the study period. Surface CH 4 CH4 concentration scans showed no signs of leaks. The substrate offered excellent conditions for the growth of methanotrophs, whose count averaged 3.91×10 8  CFU g dw −1 3.91×108 CFU g dw−1 soil

Stalz : remotely supporting the diagnosis, tracking and rehabilitation of patients with Alzheimer's

Tese de Mestrado Integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 201

Causal model to describe the variation of faecal coliform concentrations in a pilot-scale test consisting of ponds aligned in series

Abstract: In this study, the application of path analysis was tested to validate a causal model developed to verify the influence on several factors of the variation of faecal coliform concentration in pilot-scale ponds that treat domestic wastewater under distinct physical and operational characteristics. The ponds, aligned in series, are located in the city of Campina Grande, Northeastern Brazil. The model proved to be efficient for describing the variation in both secondary facultative and maturation ponds. The coefficient of determination (R2) varied between 0.66 and 0.84 for the facultative ponds and between 0.54 and 0.95 for the maturation ponds. Effluent faecal coliform concentration was negatively affected by solar radiation in shallow ponds and positively affected by influent faecal coliform concentration in deep ponds. Typically the effects related to phytoplankton photosynthetic activity were well characterized in all shallow maturation ponds. Faecal coliform concentration was negatively affected by pH in almost all the cases. This model is not suitable for anaerobic ponds.La méthodologie du Path analysis a été employé afin de tester un modèle causal qui a été développé pour vérifier l’influence de plusieurs facteurs sur la variation de la concentration en coliformes fécaux dans des étangs de traitement des eaux usées pilotes. Ces dernières sont opérées selon des caractéristiques physiques et fonctionnelles distinctes. Les étangs, alignés en série, se trouvent dans la ville de Campina Grande, dans le Nordeste brésilien. Le modèle s’est révélé efficace pour décrire la variation de la concentration de coliformes fécaux dans les étangs secondaires facultatifs, de même que dans les étangs de maturation. Le coefficient de détermination (R2) a varié de 0,66 à 0,84 dans étangs facultatifs et de 0,54 à 0,95 dans les étangs de maturation. La concentration en coliformes fécaux de l’effluent a été négativement affectée par les radiations solaires dans les étangs peu profonds et positivement affectée par la concentration en coliformes fécaux de l’influent dans les étangs profonds. Habituellement, les effets associés à l’activité de photosynthèse du phytoplancton étaient bien caractérisés dans les étangs de maturation peu profonds. La concentration en coliformes fécaux a été négativement affectée par le pH dans presque tous les cas. Ce modèle ne s’applique aux étangs anaérobies

Estudo do impacto na viabilidade celular de neuroblastomas dos produtos de pirólise de misturas herbais contendo canabinóides sintéticos

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas MonizOs primeiros registos da comercialização de misturas herbais contendo canabinóides sintéticos para fins recreativos datam do início da década passada. Desde então tem-se verificado um aumento quer no consumo destas substâncias quer na emergência de novas substâncias. De facto, o número de casos de hospitalização pelo consumo de canabinóides reportados indica um problema sério de saúde pública, agravado pela ausência de conhecimento sobre os efeitos tóxicos destas substâncias assim como dos seus efeitos farmacológicos. Com o objetivo de contribuir para o conhecimento do impacto toxicológico das misturas herbais e considerando que o consumo é feito pela inalação do fumo referidas misturas, foi utilizado um sistema de fumo para a obtenção dos produtos de pirólise dos canabinóides sintéticos. A identificação dos produtos de pirólise foi realizada por GC-MS, e a respetiva quantificação por HPLC-UV. Após a pirólise de 160 mg de “Spice”, contendo 24 mg de JWH-018, no sistema de queima recuperou-se 3,8mg deste composto e quantidades minoritárias de produtos de pirólise, não identificados pela base de dados de Massas. O impacto celular do JWH-018 e dos produtos de pirólise hidrófilos e hidrófobos da “Spice” foi avaliado na linha celular SH-SY5Y, recorrendo ao teste do MTT. O ensaio com MTT na presença das substâncias referidas na concentração de 0.0026 a 20μg/mL, não aponta uma correlação entre a concentração do pirolisado e a morte celular. No entanto, a repetição deste estudo para outras gamas de concentração de pirolisados é necessária para que se possa compreender o impacto dos produtos de pirólise e dos canabinóides sintéticos na viabilidade celular. O presente estudo é um contributo para o desenvolvimento de uma metodologia que permita medir o impacto de Novas Substâncias Psicoactivas na saúde