Desmonte de Maciços Rochosos: optimização da perfuração

Este trabalho pretende avaliar e melhorar o modo de execução da aplicação da técnica de perfuração, não comprometendo a jusante, no ciclo de operações, a qualidade do desmonte, visando assim, uma optimização técnico-económica. Este manuscrito irá centrar-se na optimização da etapa da perfuração, visando assim a optimização do ciclo total da perfuração. As tarefas realizadas numa pedreira constituem um ciclo de operações. Uma das operações envolvidas no desmonte de maciços rochosos é a perfuração. A forma como esta é executada é determinante para o sucesso do desmonte. O correcto dimensionamento dos acessórios de perfuração, afiação de bits, manutenção preventiva dos equipamentos de perfuração e a constante formação dos operadores fazem parte de um conjunto de acções que irão determinar o sucesso da operação de perfuração, tendo sempre em vista, uma optimização técnico-económica, ou seja, produzir mais a um custo mais baixo. O estudo dos parâmetros do maciço rochoso aliado a uma perfuração cuidadosa e alinhada é evidenciado com o intuito de uma abordagem de geoengenharia integrada dos maciços rochosos. O estudo foi realizado na pedreira da APS, S.A. (Pedreira de Monte Chãos), tendo como análise os dados desde o início do projecto até à data. Para fundamentar este estudo, aborda-se os parâmetros geológico-geotécnicos e geomecânicos do maciço remanescente, verificando assim as ferramentas de corte mais adequadas ao caso e averiguar a influência da afiação de bits, quer seja manual ou semiautomática, e de que forma a mesma irá influenciar nos rendimentos e vidas úteis obtidas, tendo como objectivo, melhorar o custo por metro de furação realizado.

Electricity markets modeling considering complex contracts and aggregators

All over the world, the liberalization of electricity markets, which follows different paradigms, has created new challenges for those involved in this sector. In order to respond to these challenges, electric power systems suffered a significant restructuring in its mode of operation and planning. This restructuring resulted in a considerable increase of the electric sector competitiveness. Particularly, the Ancillary Services (AS) market has been target of constant renovations in its operation mode as it is a targeted market for the trading of services, which have as main objective to ensure the operation of electric power systems with appropriate levels of stability, safety, quality, equity and competitiveness. In this way, with the increasing penetration of distributed energy resources including distributed generation, demand response, storage units and electric vehicles, it is essential to develop new smarter and hierarchical methods of operation of electric power systems. As these resources are mostly connected to the distribution network, it is important to consider the introduction of this kind of resources in AS delivery in order to achieve greater reliability and cost efficiency of electrical power systems operation. The main contribution of this work is the design and development of mechanisms and methodologies of AS market and for energy and AS joint market, considering different management entities of transmission and distribution networks. Several models developed in this work consider the most common AS in the liberalized market environment: Regulation Down; Regulation Up; Spinning Reserve and Non-Spinning Reserve. The presented models consider different rules and ways of operation, such as the division of market by network areas, which allows the congestion management of interconnections between areas; or the ancillary service cascading process, which allows the replacement of AS of superior quality by lower quality of AS, ensuring a better economic performance of the market. A major contribution of this work is the development an innovative methodology of market clearing process to be used in the energy and AS joint market, able to ensure viable and feasible solutions in markets, where there are technical constraints in the transmission network involving its division into areas or regions. The proposed method is based on the determination of Bialek topological factors and considers the contribution of the dispatch for all services of increase of generation (energy, Regulation Up, Spinning and Non-Spinning reserves) in network congestion. The use of Bialek factors in each iteration of the proposed methodology allows limiting the bids in the market while ensuring that the solution is feasible in any context of system operation. Another important contribution of this work is the model of the contribution of distributed energy resources in the ancillary services. In this way, a Virtual Power Player (VPP) is considered in order to aggregate, manage and interact with distributed energy resources. The VPP manages all the agents aggregated, being able to supply AS to the system operator, with the main purpose of participation in electricity market. In order to ensure their participation in the AS, the VPP should have a set of contracts with the agents that include a set of diversified and adapted rules to each kind of distributed resource. All methodologies developed and implemented in this work have been integrated into the MASCEM simulator, which is a simulator based on a multi-agent system that allows to study complex operation of electricity markets. In this way, the developed methodologies allow the simulator to cover more operation contexts of the present and future of the electricity market. In this way, this dissertation offers a huge contribution to the AS market simulation, based on models and mechanisms currently used in several real markets, as well as the introduction of innovative methodologies of market clearing process on the energy and AS joint market. This dissertation presents five case studies; each one consists of multiple scenarios. The first case study illustrates the application of AS market simulation considering several bids of market players. The energy and ancillary services joint market simulation is exposed in the second case study. In the third case study it is developed a comparison between the simulation of the joint market methodology, in which the player bids to the ancillary services is considered by network areas and a reference methodology. The fourth case study presents the simulation of joint market methodology based on Bialek topological distribution factors applied to transmission network with 7 buses managed by a TSO. The last case study presents a joint market model simulation which considers the aggregation of small players to a VPP, as well as complex contracts related to these entities. The case study comprises a distribution network with 33 buses managed by VPP, which comprises several kinds of distributed resources, such as photovoltaic, CHP, fuel cells, wind turbines, biomass, small hydro, municipal solid waste, demand response, and storage units.

Juvenile Parkinson disease caused by parkin mutations: large deletions and pathogenic mechanisms

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Performance of state space and ARIMA models for consumer retail sales forecasting

Forecasting future sales is one of the most important issues that is beyond all strategic and planning decisions in effective operations of retail businesses. For profitable retail businesses, accurate demand forecasting is crucial in organizing and planning production, purchasing, transportation and labor force. Retail sales series belong to a special type of time series that typically contain trend and seasonal patterns, presenting challenges in developing effective forecasting models. This work compares the forecasting performance of state space models and ARIMA models. The forecasting performance is demonstrated through a case study of retail sales of five different categories of women footwear: Boots, Booties, Flats, Sandals and Shoes. On both methodologies the model with the minimum value of Akaike's Information Criteria for the in-sample period was selected from all admissible models for further evaluation in the out-of-sample. Both one-step and multiple-step forecasts were produced. The results show that when an automatic algorithm the overall out-of-sample forecasting performance of state space and ARIMA models evaluated via RMSE, MAE and MAPE is quite similar on both one-step and multi-step forecasts. We also conclude that state space and ARIMA produce coverage probabilities that are close to the nominal rates for both one-step and multi-step forecasts.

Metodologias no Controlo de Compactação em Aterros

O presente trabalho pretende abordar aspectos relacionados com o controlo de compactação em aterros, com base na avaliação de parâmetros “in situ”, tais como: pesos volúmicos, teores em água, graus de compactação e módulos de deformabilidade. Recorrendo aos métodos correntes no controlo de compactação, como o ensaio de carga em placa, gamadensímetro, garrafa e ao ensaio de deflectómetro de impacto portátil. Visa-se comparar os resultados obtidos, nas diferentes condições, de modo a possibilitar alcançar correlações entre os ensaios, bem como determinar aqueles que apresentam maior grau de confiança técnico e vantagens operacionais e económicas. De modo a garantir os índices de qualidade da obra é necessário fazer cumprir os critérios exigidos pelo caderno de encargos, nomeadamente nos parâmetros de avaliação do controlo de compactação, para que estas satisfaçam o seu estado funcional e estrutural. Neste tipo de obras os cadernos de encargos de referência em Portugal são os das Estradas de Portigal (EP) e da Brisa, Auto-estradas de Portugal (Brisa), os quais se baseiam em recomendações de classificações de solos. No contexto experimental, foram efectuados dois estudos com condições e materiais diferentes, em obras pertencentes à empresa Mota-Engil Engenharia e Construções, S.A. Nas campanhas de ensaios foram realizados ensaios “in situ” na obra da Subconcessão do Douro Interior – Lote 6 – IC5 – Troço Murça/ Nó de Pombal nas camadas de sub-base e base num agregado de granulometria extensa, e na obra de modernização do troço ferroviário Bombel e Vidigal a Évora, em solos.

A qualitive reasoning approach for improving query results for sketch based queries by topological analysis of spatial aggregation

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Reabilitação de um Edifício de Serviços no Porto para função de Hotel

Este relatório de estágio aborda o tema da reabilitação, referindo-se a uma intervenção da especialidade e também construção de raíz, de um Hotel situado na rua do Heroísmo no Porto. Portugal possui um edificado que tem vindo a degradar-se ao longo dos últimos anos, devido essencialmente à falta de operações periódicas de manutenção, conservação e reabilitação. Esta degradação resulta não só do mau estado de conservação generalizado dos edifícios, mas também da inexistência de infra-estruturas urbanísticas em devido funcionamento. Tal conjunto de situações, leva a um movimento migratório dos habitantes das cidades para as respetivas periferias. A cidade do Porto não é uma exceção, estando a necessitar de um forte esforço de reabilitação para inverter esta situação. Ao longo dos últimos anos têm vindo a ser criados diversos apoios financeiros, nacionais e europeus, com o objetivo de ajudar as operações de reabilitação. Mais recentemente foi possibilitada a criação de Sociedades de Reabilitação Urbana (SRU), cujo objetivo é o de promover e orientar todo o processo de reabilitação, de forma a regula-lo nos centros das cidades. No entanto a intervenção de reabilitação de um edifício é uma operação complexa, com diversas especificidades e com inúmeras condicionantes devido às pré-existências próprias de cada edifício.

Development of novel human cellular models for neurotoxicity studies

Dissertation to obtain master degree in Genética Molecular e Biomedicina

Impact of Syncope on Quality of Life: Validation of a Measure in Patients Undergoing Tilt Testing

INTRODUCTION AND OBJECTIVES: Recurrent syncope has a significant impact on quality of life. The development of measurement scales to assess this impact that are easy to use in clinical settings is crucial. The objective of the present study is a preliminary validation of the Impact of Syncope on Quality of Life questionnaire for the Portuguese population. METHODS: The instrument underwent a process of translation, validation, analysis of cultural appropriateness and cognitive debriefing. A population of 39 patients with a history of recurrent syncope (>1 year) who underwent tilt testing, aged 52.1 ± 16.4 years (21-83), 43.5% male, most in active employment (n=18) or retired (n=13), constituted a convenience sample. The resulting Portuguese version is similar to the original, with 12 items in a single aggregate score, and underwent statistical validation, with assessment of reliability, validity and stability over time. RESULTS: With regard to reliability, the internal consistency of the scale is 0.9. Assessment of convergent and discriminant validity showed statistically significant results (p<0.01). Regarding stability over time, a test-retest of this instrument at six months after tilt testing with 22 patients of the sample who had not undergone any clinical intervention found no statistically significant changes in quality of life. CONCLUSIONS: The results indicate that this instrument is of value for assessing quality of life in patients with recurrent syncope in Portugal.

Politics, Commerce, and Colonization in Angola at the Turn of the Eighteenth Century

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em História Moderna e dos Descobrimentos

Lime based mortars for ceramic tile application: the influence of the lime, the use of a metakaolin and the curing

Intern.Conference AZULEJAR, Univ. Aveiro, 10-12 October 2012

Facing unemployment after being at the top: impact, job search strategies and crucial competences

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

A clinico-pathological study of 163 untreated cases of chronic hepatitis C

We performed a clinico-pathological study of 163 untreated cases of chronic hepatitis C. Eighty five percent of the patients were clinically asymptomatic and their physical examinations sbowed unremarkable or minimal changes at the time of the liver biopsy Liver function tests tended to present slight abnormalities, involving mild elevations of the activity of the aminotransferases and gamma-glutamil transferase levels. In spite of these mild abnormalities advanced chronic liver disease ivas histologically detected in eighty nine percent of the patients, mainly showing chronic active hepatitis. The most characteristic histological finding ivas an interlobular bile duct damage which correlated with the presence of tymphoid aggregates in the portal tracts and with the development of fibrosis.

Chromatic reintegration of historical mortars with lime-based pozzolanic consolidant products

3rd Historic Mortars Conference, 11-14 September 2013, Glasgow, Scotland

Influence of curing conditions in lime-metakaolin blended mortars – A mineralogical and mechanical study

3rd Historic Mortars Conference, 11-14 September 2013, Glasgow, Scotland