A tributação das sociedades gestoras de participações sociais em Portugal (regime comparativo com o RETGS)

Mestrado em Fiscalidade

Moisture recycling in the Iberian Peninsula from a regional climate simulation: spatiotemporal analysis and impact on the precipitation regime

The contribution of the evapotranspiration from a certain region to the precipitation over the same area is referred to as water recycling. In this paper, we explore the spatiotemporal links between the recycling mechanism and the Iberian rainfall regime. We use a 9 km resolution Weather Research and Forecasting simulation of 18 years (1990-2007) to compute local and regional recycling ratios over Iberia, at the monthly scale, through both an analytical and a numerical recycling model. In contrast to coastal areas, the interior of Iberia experiences a relative maximum of precipitation in spring, suggesting a prominent role of land-atmosphere interactions on the inland precipitation regime during this period of the year. Local recycling ratios are the highest in spring and early summer, coinciding with those areas where this spring peak of rainfall represents the absolute maximum in the annual cycle. This confirms that recycling processes are crucial to explain the Iberian spring precipitation, particularly over the eastern and northeastern sectors. Average monthly recycling values range from 0.04 in December to 0.14 in June according to the numerical model and from 0.03 in December to 0.07 in May according to the analytical procedure. Our analysis shows that the highest values of recycling are limited by the coexistence of two necessary mechanisms: (1) the availability of sufficient soil moisture and (2) the occurrence of appropriate synoptic configurations favoring the development of convective regimes. The analyzed surplus of rainfall in spring has a critical impact on agriculture over large semiarid regions of the interior of Iberia.

Renewable power forecast to scheduling of thermal units

In this work is discussed the importance of the renewable production forecast in an island environment. A probabilistic forecast based on kernel density estimators is proposed. The aggregation of these forecasts, allows the determination of thermal generation amount needed to schedule and operating a power grid of an island with high penetration of renewable generation. A case study based on electric system of S. Miguel Island is presented. The results show that the forecast techniques are an imperative tool help the grid management.

Plantas do Neogénico e paleoclimas. Evidências em Portugal

Ciências Geológicas: Ensino e Investigação. Vol. I: 357-363

IVA : o regime de contabilidade de caixa e o ciclo de caixa das empresas

Mestrado em Fiscalidade

Contributo das tecnologias de informação na gestão do regime terapêutico no diabético

A diabetes é a doença do seculo XXI, atinge mais de um milhão de portugueses cada vez mais jovens em idades trabalhadoras, e já custa mais de 1% do PIB, além dos enormes danos que pode causar às pessoas e à sociedade. Segundo o Relatório Anual do Observatório Nacional da Diabetes, em 2011, cerca de um quarto da população portuguesa integrada no escalão etário dos 60 aos 79 tem Diabetes. Um estudo realizado pelo Lisbon Internet and Networks Institute (LINI), em 2010, diz-nos que “a internet é um recurso para a informação e educação para a saúde”. Em 2010 49% dos lares portugueses possuem acesso à internet e 44% da população é utilizadora (acréscimo significativo relativamente aos 29% em 2003). Destes, dois terços têm entre os 15 e os 24 anos. Os idosos representam 1,6%, dos quais os reformados e pensionistas representam 5%, as domésticas representam 11% e os trabalhadores manuais 22%, sendo estes os menos utilizadores. Um terço da restante população procura informação sobre saúde semanalmente, cerca de 16%. Face à atual conjuntura económica, com restrições orçamentais, nomeadamente na área da saúde, devem-se encontrar meios para prevenir e lidar com a Diabetes numa perspetiva de custo-benefício, isto porque a Diabetes pode reduzir as oportunidades de emprego e de aprendizagem. O atual diretor da Organização para a Cooperação e Desenvolvimento Económico (OCDE) Yyes Leterme diz que “Prevenir e tratar a Diabetes e as suas complicações custa cerca de 90 mil milhões de euros anualmente na Europa”. Atualmente, não é muito utilizado nem explorado o potencial das tecnologias de informação e as ferramentas web ao serviço da saúde, quer por profissionais de saúde, quer por utentes na gestão ao regime terapêutico na doença crónica, mais precisamente na gestão adequada da Diabetes. Potenciar uma visão integrada dos diferentes recursos de comunicação e a sua utilização conjugada com a promoção da saúde e prevenção da doença poderá enfatizar em termos de eficácia e eficiência a minimização de recursos das organizações de saúde e promover a gestão adequada da Diabetes. Tendo por base esta problemática, este estudo pretende abordar e refletir o possível contributo das tecnologias de informação e das ferramentas web na gestão adequada ao regime terapêutico da Diabetes.

New simple digital self-calibration technique for pipeline ADCs using the internal thermal noise

IEEE International Symposium on Circuits and Systems, pp. 232 – 235, Seattle, EUA

Simulação laboratorial e numérica da remoção, em regime transiente, de tolueno da água através de arrastamento por ar

O tolueno tem uma vasta aplicação industrial e apresenta alguns riscos para a saúde humana. A existência de deficientes redes de infra-estruturas de saneamento básico e de protecções ambientais adequadas promovem, com relativa facilidade, a poluição de recursos hídricos subterrâneos com este tipo de composto orgânico volátil (COV). Legislação comunitária, recentemente publicada, exige que se cumpra a médio prazo padrões mínimos de qualidade apontando como limite máximo de concentração de tolueno na água destinada a consumo humano o valor de 1 miligrama por litro. O processo de arrastamento por ar em colunas com enchimento desordenado é uma das técnicas de remoção disponíveis, embora ainda pouco implementada no nosso país. Neste trabalho simulouse, laboratorial e numericamente, a remoção do tolueno da água, em regime transiente, através desta tecnologia sob condições operatórias pré-estabelecidas.

(Des)vantagens do regime especial de tributação dos grupos de sociedades

Dissertação para obtenção do Grau de Mestre em Contabilidade e Finanças Orientador: Mestre, Gabriela Pinheiro

Self-scheduling and bidding strategies of thermal units with stochastic emission constraints

This paper is on the self-scheduling problem for a thermal power producer taking part in a pool-based electricity market as a price-taker, having bilateral contracts and emission-constrained. An approach based on stochastic mixed-integer linear programming approach is proposed for solving the self-scheduling problem. Uncertainty regarding electricity price is considered through a set of scenarios computed by simulation and scenario-reduction. Thermal units are modelled by variable costs, start-up costs and technical operating constraints, such as: forbidden operating zones, ramp up/down limits and minimum up/down time limits. A requirement on emission allowances to mitigate carbon footprint is modelled by a stochastic constraint. Supply functions for different emission allowance levels are accessed in order to establish the optimal bidding strategy. A case study is presented to illustrate the usefulness and the proficiency of the proposed approach in supporting biding strategies. (C) 2014 Elsevier Ltd. All rights reserved.

Os Dízimos no Final do Antigo Regime: aspectos económicos e sociais (Minho, 1820-1834)

Dissertação de Mestrado em História dos Séculos XIX-XX (secção do século XIX)

Characterisation and electrochemical behaviour of electrodeposited Cu-Fe foams applied as pseudocapacitor electrodes

Copper iron (Cu-Fe) 3D porous foams for supercapacitor electrodes were electrodeposited in the cathodic regime, on stainless steel current collectors, using hydrogen bubbling dynamic template. The foams were prepared at different current densities and deposition times. The foams were submitted to thermal conditioning at temperatures of 150 and 250 degrees C. The morphology, composition and structure of the formed films were studied by SEM, EDS and XRD, respectively. The electrochemical behaviour was studied by cyclic voltammetry, electrochemical impedance spectroscopy and chronopotentiometry. The morphology of the 3D Cu-Fe foams is sensitive to the electrodeposition current and time. The increase of the current density produces a denser, larger and more ramified dendritic structure. Thermal conditioning at high temperature induces a coarser grain structure and the formation of copper oxides, which affect the electrochemical behaviour. The electrochemical response reveals the presence of various redox peaks assigned to the oxidation and reduction of Cu and Fe oxides and hydroxides in the foams. The specific capacitance of the 3D Cu Fe foams was significantly enhanced by thermal conditioning at 150 degrees C. The highest specific capacitance values attained 297 Fg(-1) which are much above the ones typically observed for single Cu or Fe Oxides and hydroxides. These values highlight a synergistic behaviour resulting from the combination of Cu and Fe in the form of nanostructured metallic foams. Moreover, the capacitance retention observed in an 8000 charge/discharge cycling test was above 66%, stating the good performance of these materials and its enhanced electrochemical response as supercapacitor negative electrodes. (C) 2014 Elsevier B.V. All rights reserved.

Mechanical and thermal characterization of a structural polyurethane adhesive modified with thermally expandable particles

Thermally expandable particles (TEPs) are used in a wide variety of applications by industry mainly for weight reduction and appearance improvement for thermoplastics, inks, and coatings. In adhesive bonding, TEPs have been used for recycling purposes. However, TEPs might be used to modify structural adhesives for other new purposes, such as: to increase the joint strength by creating an adhesive functionally modified along the overlap of the joint by gradual heating and/or to heal the adhesive in case of damage. In this study, the behaviour of a structural polyurethane adhesive modified with TEPs was investigated as a preliminary study for further investigations on the potential of TEPs in adhesive joints. Tensile bulk tests were performed to get the tensile properties of the unmodified and TEPs-modified adhesive, while Double Cantilever Beam (DCB) test was performed in order to evaluate the resistance to mode I crack propagation of unmodified and TEPs-modified adhesive. In addition, in order to investigate the behaviour of the particles while encapsulated in adhesives, a thermal analysis was done. Scanning electron microscopy (SEM) was used to examine the fracture surface morphology of the specimens. The fracture toughness of the TEPs-modified adhesive was found to increase by addition of TEPs, while the adhesive tensile strength at yield decreased. The temperature where the particles show the maximum expansion varied with TEPs concentration, decreasing with increasing the TEPs content.

A MOSFET-only wideband LNA exploiting thermal noise canceling and gain optimization

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Electrotécnica e de Computadores