Controlo inteligente de um Sistema de Levitação Magnética

A levitação magnética tem sido um tema bastante investigado sobretudo devido à sua utilização em sistemas ferroviários de transportes. É o método ideal quando existe a necessidade em aplicações de restringir do contacto físico, ou a conveniência, em termos energéticos, de eliminar o atrito. O princípio de funcionamento é simples, um eletroíman cria uma força sobre um objeto ferromagnético que contraria a gravidade. Contudo um sistema de levitação por atração é instável e não linear, o que significa a necessidade de implementar um controlador para satisfazer as características de estabilidade desejadas. Ao longo deste projeto serão descritos os procedimentos teóricos e práticos que foram tomados na criação de um sistema de levitação eletromagnética. Desde a conceção física do sistema, como escolha do sensor, condicionamento de sinal ou construção do eletroíman, até aos procedimentos matemáticos que permitiram a modelação do sistema e criação de controladores. Os controladores clássicos, como o PID ou em avanço de fase, foram projetados através da técnica do Lugar Geométrico de Raízes. No projeto do controlador difuso, pelo contrário não se fez uso da modelação do sistema ou de qualquer relação matemática entre as variáveis. A utilização desta técnica de controlo destacou-se pela usa simplicidade e rapidez de implementação, fornecendo um bom desempenho ao sistema. Na parte final do relatório os resultados obtidos pelos diferentes métodos de controlo são analisados e apresentadas as respetivas conclusões. Estes resultados revelam que para este sistema, relativamente aos outros métodos, o controlador difuso apresenta o melhor desempenho tanto ao nível da resposta transitória, como em regime permanente.

Projeto de estruturas do edifício administrativo de um polo logístico em Viana-Angola

O objetivo deste trabalho consiste em efetuar o dimensionamento estrutural de um edifício em betão armado, contemplando as diferentes fases, desde a conceção inicial, com a definição do modelo estrutural e escolha criteriosa dos elementos e soluções constituintes, até à fase final de dimensionamento, considerando para além das cargas gravíticas, a ação do vento e a ação sísmica. No âmbito deste trabalho considerou-se o dimensionamento de elementos estruturais nomeadamente, sapatas, paredes, pilares, vigas e lajes, com a verificação de segurança à flexão simples, flexão composta, esforço transverso e punçoamento, consoante a necessidade de cada elemento. Para tal, foi desenvolvido uma folha de cálculo automático (Macro) que permite a verificação da capacidade resistente de secções, à flexão simples e ao esforço transverso, quer em elementos com ou sem armadura de esforço transverso. Os esforços atuantes que estiveram na origem das verificações estruturais foram calculados com base na aplicação de um programa tridimensional de elementos finitos, nomeadamente o programa de cálculo ROBOT STRUCTURAL ANALYSIS. Os Critérios Gerais de Dimensionamento considerados, com base na regulamentação em vigor em Portugal – RSA, REBAP e Eurocódigos, bem como as Hipóteses de Cálculo consideradas na verificação aos estados limites últimos dos elementos estruturais são detalhadamente enunciados ao longo do trabalho. Os desenhos de elementos estruturais dimensionados, bem como os desenhos de dimensionamento do edifício encontram-se em Anexo.

Towards cryogenic liquid –vapor energy storage units for space applications

Dissertation to obtain the Doctoral degree in Physics Engineering

Avaliação epidemiológica dos internamentos através de um serviço de urgência de segunda linha (SII)

RESUMO: Introdução: A Comissão Nacional para a reestruturação dos Serviços de Saúde Mental em 2004, fez uma proposta de âmbito regional, ao nível da região de Saúde do Norte, levando a uma alteração da rede de referenciação hospitalar dos internamentos em psiquiatria. Métodos: Realizou-se um estudo epidemiológico longitudinal para avaliar factores preditivos de internamento através de um serviço de Urgência de Segunda Linha (SII), que de algum modo reflectisse o funcionamento dos serviços de internamento na região de Saúde do Norte, ao longo de 12 anos, nomeadamente relacionando com factores organizacionais contemplados no Plano Nacional de Saúde Mental e na reorganização da rede de referenciação hospitalar. Resultados: Durante os 12 anos do estudo, verificou-se um aumento estatisticamente significativo do número e duração de internamentos através do SII, com ponto de partida no ano 2008-2009, e de novo a partir do ano 2010-2011 (nº de internamentos), para o qual contribuiu a alteração da rede hospitalar na região de saúde do Norte, nomeadamente pelo facto do HMLemos, assumir a responsabilidade de novo, dos internamentos das áreas de Famalicão, Gondomar e Santa Maria da Feira. Em relação ao número de internamentos, e na análise exploratória, encontramos nas áreas hospitalares fora da área de influência do HMLemos, uma contribuição positiva significativa para o aumento do nº de internamentos ao longo dos anos com os Dx (290, 296, 297, 291, 309). Em relação à área do HMLemos restrita (PVC, STT, Matosinhos, Porto Ocidental), de referir a contribuição positiva significativa dos Dx 309 e 301, para o aumento do número de internamentos ao longo do tempo, sendo que a prevalência maior se mantém relacionada às Psicoses (Dx 295, 296 e 297). Não se concluiu por uma contribuição estatisticamente significativa ( positiva ou negativa), das variáveis independentes idade, sexo ou natureza do internamento em relação à variável dependente ( duração de internamentos/ano). Em relação á variável dependente (nº de internamentos/ano), relativamente aos doentes fora de área de influência do HMLemos, concluiu-se uma contribuição positiva estatisticamente significativa da variável independente idade. Conclusões: Através da análise exploratória foi possível perceber o esforço realizado pelos hospitais no sentido de melhorar a equidade e acessibilidade dos doentes à Saúde Mental, a par da reorganização da rede hospitalar. De destacar a necessidade de encontrar alternativas às situações de internamento, com menos critérios de gravidade diagnóstica, nomeadamente reforçar a importância da criação de consultas de crises nos respectivos Hospitais de Dia dos DPSM.----------------ABSTRACT:Introduction : The National Commission for the restructuring of mental health services in 2004 , has proposed at a regional level ( North Health Region), a change in the network of hospital referrals of admissions in psychiatry. Methods: We conducted a longitudinal epidemiological study to assess predictors of hospitalization through a Second Line Emergency Service ( SII) , that somehow reflect the operation of inpatient services in North Health Region, over 12 years, particularly relating to organizational factors included in the National Mental Health Plan and reorganization of the hospital referral network. Results: During the period of the study, there was a statistically significant increase in the number and duration of hospitalizations through the SII, with starting point in the year 2008-2009 and again from 2010-2011 (number of admissions) , for which counted the change of the hospital network referral in Northern health region , in particular because Hospital Magalhães Lemos (HMLemos) , took the new responsibility of admissions from areas of Famalicão, Gondomar and Santa Maria da Feira . Regarding the number of hospitalizations, in the exploratory analysis , we found in hospital areas outside the area of influence of HMLemos , a significant positive contribution to the increase in number of admissions over the years with Diagnosis of 290, 296, 297, 291 , 309 in the ICD-9. With respect to the restricted area of HMLemos (PVC, STT , Porto Ocidental and Matosinhos) , we found a significant positive contribution of Diagnosis 309 and 301, to increase the number of hospitalizations over time, with higher prevalence rates remaining the psychoses ( Dx 295, 296 and 297 ) . Did not conclude for any statistically significant contribution (positive or negative) of the independent variables age, sex and nature of admission to the dependent variable (duration of hospitalization / year). In relation to the dependent variable (number of admissions / year) relative to patients outside the area of influence of HMLemos, it was found a statistically significant positive contribution of the independent variable age . Conclusions: Through the exploratory analysis, it was possible to see the efforts made by hospitals to improve the accessibility of patients to Mental Health, throughout the hospital network reorganization. Its important to highlight the need to find alternatives to inpatient admissions in those with less gravity diagnostic criteria, reinforcing the importance of creating specific crisis consultations in Day Hospital regime.

40 K Neon liquid energy storage unit

Cryocoolers have been progressively replacing the use of the stored cryogens in cryogenic chains used for detector cooling, thanks to their higher and higher reliability. However, the mechanical vibrations, the electromagnetic interferences and the temperature fluctuations inherent to their functioning could reduce the sensor’s sensitivity. In order to minimize this problem, compact thermal energy storage units (ESU) are studied, devices able to store thermal energy without significant temperature increase. These devices can be used as a temporary cold source making it possible to turn the cryocooler OFF providing a proper environment for the sensor. A heat switch is responsible for the thermal decoupling of the ESU from the cryocooler’s temperature that increases when turned OFF. In this work, several prototypes working around 40 K were designed, built and characterized. They consist in a low temperature cell that contains the liquid neon connected to an expansion volume at room temperature for gas storage during the liquid evaporation phase. To turn this system insensitive to the gravity direction, the liquid is retained in the low temperature cell by capillary effect in a porous material. Thanks to pressure regulation of the liquid neon bath, 900 J were stored at 40K. The higher latent heat of the liquid and the inexistence of triple point transitions at 40 K turn the pressure control during the evaporation a versatile and compact alternative to an ESU working at the triple point transitions. A quite compact second prototype ESU directly connected to the cryocooler cold finger was tested as a temperature stabilizer. This device was able to stabilize the cryocooler temperature ((≈ 40K ±1 K) despite sudden heat bursts corresponding to twice the cooling power of the cryocooler. This thesis describes the construction of these devices as well as the tests performed. It is also shown that the thermal model developed to predict the thermal behaviour of these devices, implemented as a software,describes quite well the experimental results. Solutions to improve these devices are also proposed.

40 K neon liquid energy storage unit

Cryocoolers have been progressively replacing the use of the stored cryogens in cryogenic chains used for detector cooling, thanks to their higher and higher reliability. However, the mechanical vibrations, the electromagnetic interferences and the temperature fluctuations inherent to their functioning could reduce the sensor’s sensitivity. In order to minimize this problem, compact thermal energy storage units (ESU) are studied, devices able to store thermal energy without significant temperature increase. These devices can be used as a temporary cold source making it possible to turn the cryocooler OFF providing a proper environment for the sensor. A heat switch is responsible for the thermal decoupling of the ESU from the cryocooler’s temperature that increases when turned OFF. In this work, several prototypes working around 40 K were designed, built and characterized. They consist in a low temperature cell that contains the liquid neon connected to an expansion volume at room temperature for gas storage during the liquid evaporation phase. To turn this system insensitive to the gravity direction, the liquid is retained in the low temperature cell by capillary effect in a porous material. Thanks to pressure regulation of the liquid neon bath, 900 J were stored at 40K. The higher latent heat of the liquid and the inexistence of triple point transitions at 40 K turn the pressure control during the evaporation a versatile and compact alternative to an ESU working at the triple point transitions. A quite compact second prototype ESU directly connected to the cryocooler cold finger was tested as a temperature stabilizer. This device was able to stabilize the cryocooler temperature ((≈ 40K ±1 K) despite sudden heat bursts corresponding to twice the cooling power of the cryocooler. This thesis describes the construction of these devices as well as the tests performed. It is also shown that the thermal model developed to predict the thermal behaviour of these devices,implemented as a software, describes quite well the experimental results. Solutions to improve these devices are also proposed.

Plasmodium falciparum infection in pregnant women attending antenatal care in Luanda, Angola

INTRODUCTION: Malaria during pregnancy remains a serious public health problem. The aim of this study was to establish the prevalence and possible risk factors for malaria in pregnant women attending antenatal care at Augusto Ngangula Specialized General Hospital in Luanda, Angola. METHODS: Pregnant women (679 total) who attended antenatal care from April to September 2008 were included in the study after signing informed consent. For each participant, the social-demographic profile and malaria and obstetric histories were investigated via a questionnaire. Diagnosis was made by optic microscopy, and hemoglobin concentration measured. The associations between age, parity, gestational age, residence, schooling, malaria during gravity, anemia and treatment with incidence of Plasmodium falciparum infection were analyzed through logistic regression. RESULTS: During the period of study, 74 (10.9%) out of 679 women were infected by P. falciparum. The average concentration of hemoglobin was 11.1 ± 0.07g/dL, and there were significant associations between the history of malaria during pregnancy, P. falciparum infection (p<0.01) and anemia at the time of observation (p<0.001). CONCLUSIONS: Previous history of malaria during pregnancy represents a risk factor for current infection and anemia was an important complication associated with malaria, even in women who were treated with sulfadoxine-pyrimethamine during pregnancy.

Indicadores de qualidade na emergência médica pré-hospitalar : painel operacional para o INEM, I.P.

RESUMO - A Emergência Médica Pré-Hospitalar é uma parte importante na cadeia de cuidados de saúde, quer pela gravidade das situações a que atende, quer por funcionar como gatekeeper. O estudo é dedicado a instrumentos de medição e em simultâneo a medições de qualidade como processo de melhoria contínua da qualidade na EMPH. Existem projetos a nível internacional para implementação de painéis de indicadores, alguns atribuem significativa relevância aos processos assistenciais. O European Emergency Data Project (EDD) foi selecionado para servir como painel de indicadores a explorar neste trabalho. Porque a nível científico está bem desenhado, as definições e variáveis estão bem explicitadas e interessa ao INEM, I.P. utilizar um painel que lhe permita um benchmarking. Criou-se um dashboard para os indicadores selecionados e com ele analisaram-se os dados para aferir a qualidade do SEM. Não foi possível, pela sua inexistência, coletar dados para dois dos indicadores propostos. Foram apresentadas propostas de melhoria no sistema de captação de dados do INEM, I.P. para que a instituição possa monitorizar periodicamente os indicadores selecionados. A existência de dados e a sua fiabilidade para utilizar na medição por indicadores é algo que se explorou neste trabalho de campo, e as fraquezas encontradas foram matéria para oportunidades, recomendações, e caminho para discussão e o fortalecimento da instituição.

Drilling deeper: Understanding trade in Angola

The present study analyzes Angola’s trading partners from 2005 to 2015 in order to understand the main drivers of Exports and Imports growth. Departing from a gravity model, foreign GDP growth and real exchange rate fluctuations were interpreted as demand and supply disturbances on Exports. While nominal and real exports both increase with demand expansions, they react differently to supply shocks. Imports are growing at the same rate as Angola’s economy while exchange rate fluctuations capture the wealth effect of Oil price in the economy.

Relatório de estágio no departamento central de investigação e acção penal

The means of obtaining evidence, the amount of evidence obtained, the number of defendants related to each criminal case and the gravity of the crimes for which the magistrates of the Department are holders of penal action, define its real importance to the Rule of Law. I have deeply studied the subject of the institution of hierarchical intervention required by the assistant and the application of an opening statement by the defendant, starting from a hypothetical case, provided when the query of an investigation with the subject of the crime of active corruption, where this institution was called as a reaction to the archiving dispatch delivered by the Public Ministry. I have study about the implementation of the institution of provisional suspension of the process, specifically in the scope of fiscal criminality, analyzing the effective satisfaction of the purposes of the sentences in two slopes: general prevention and special prevention. I went for my first time to a Central Court of Criminal Instruction, where I attended the measures of inquiry and instructive debate of a process that culminated with the prosecution and pronunciation of the defendants. In addition to this criminal experience, I have deepened and consolidated the academic knowledge with the study of various criminal cases from various fields in the scope of criminality investigated by the Department. I could therefore check the basis of procedural delays, regarding to our legal system, especially in this type of crime, raising issues that I analyzed and discussed, always in a critical and academic way. I had the opportunity to attend and witness a seminar in the Lisbon Directorate of Finance as well of entering the Centre for Judicial Studies to attend a conference on the International Anti-Corruption Day. Focus on the investigatory importance of the international judicial cooperation, through the various organs, with special interest to EUROJUST. I comprehended the organization and functioning of these communitarian organs and means of communication of procedural acts, in particular, the rogatory letters and european arrest warrants. This involvement is motivated by the moratorium factor of the investigations where rogatory letters are necessary for the acquisition of evidence or information relevant to the good continuation of the process. For this reason the judicial cooperation through the relevant communitarian organs, translates a streamlined response between the competent judicial authorities of the Member States, through the National Member that integrates EUROJUST. This report aims to highlight some of the difficulties and procedural issues that Public Prosecutors of DCIAP and criminal police bodies that assist them, face in combating violent and organized crime, of national and transnational nature, of particular complexity, according to the specifics of criminal types.

Gestão de crises de âmbito policial

The issues concerning Crisis Situations under the scope of police activity, raised after incidents considered critical, has emerged with greater intensity during the most recent decades, posing a major challenge for police forces around the world. These are situations or events of crucial importance, involving hostage taken or barricaded individuals, in which inevitably human lives are at risk, requiring from law enforcement agencies a specific response capability, i.e., a type of intervention not framed under the parameters considered as routine, in order to obtain solutions to minimize the possibility of casualties. Because this is about impacting situations of extreme gravity, where the preservation of human lives is concerned and, in many cases, the very Rule of Law as well, we understand the need for police forces to adapt to new procedures and working methods. Such procedures are an enormously complex task that requires the coordination and articulation of several components, including not infrequently the performance of different police forces, as well as organizations and entities with varied powers and duties, which implies the need for effective management. This explains the emergence of Crisis Management Structures, imposing to determine which are their fundamental components, their importance, how they interconnect, and their major goal. The intrinsic features will also be analyzed in the aspect that we consider to be the fundamental groundwork of a Crisis Management Structure, i.e., Negotiation itself, considering it as a kind of police intervention, where a wide range of procedures feeds a channel of dialogue, aiming at minimizing the damage resultant from an extreme action, in particular, to prevent the death of any of those involved. This is in essence the path we have chosen to develop this study, trying to find out an answer to the fundamental question: What model of Crisis Management Structure should be adopted to manage a critical event involving hostage negotiation?

Wood density of trees in black water floodplains of Rio Jaú National Park, Amazonia, Brazil

The Jaú National Park is the largest protected forested area in the world. The Vitória Amazônica Foundation is working towards understanding its ecosystem, to which this paper contributes. Wood density was analysed in 27 common tree species growing in the blackwater flood-plains of the Rio Jaú, an affluent of the Rio Negro (Amazonia, Brazil). Wood was sampled with an increment borer. Mean wood density of the analysed species ranged from 0.35 to 0.87 g cm-3. The mean of all sampled species was 0.67 g cm-3 (st. dev. 0.13). Lowest density was found for Hevea spruceana with 0.32 g cm-3 and highest for Crudia amazonica with 0.9 g cm-3.

O Esclavagismo dos Tempos Modernos e a Tutela Jurídica das suas Vítimas: os meios jurídicos ao serviço da recuperação psicológica das vítimas de tráfico de seres humanos

Dissertação de mestrado em Direitos Humanos

Time-variations of equivalent water heights'from Grace Mission and in-situ river stages in the Amazon basin

Gravity Recovery and Climate Experiment (GRACE) mission is dedicated to measuring temporal variations of the Earth's gravity field. In this study, the Stokes coefficients made available by Groupe de Recherche en Géodésie Spatiale (GRGS) at a 10-day interval were converted into equivalent water height (EWH) for a ~4-year period in the Amazon basin (from July-2002 to May-2006). The seasonal amplitudes of EWH signal are the largest on the surface of Earth and reach ~ 1250mm at that basin's center. Error budget represents ~130 mm of EWH, including formal errors on Stokes coefficient, leakage errors (12 ~ 21 mm) and spectrum truncation (10 ~ 15 mm). Comparison between in situ river level time series measured at 233 ground-based hydrometric stations (HS) in the Amazon basin and vertically-integrated EWH derived from GRACE is carried out in this paper. Although EWH and HS measure different water bodies, in most of the cases a high correlation (up to ~80%) is detected between the HS series and EWH series at the same site. This correlation allows adjusting linear relationships between in situ and GRACE-based series for the major tributaries of the Amazon river. The regression coefficients decrease from up to down stream along the rivers reaching the theoretical value 1 at the Amazon's mouth in the Atlantic Ocean. The variation of the regression coefficients versus the distance from estuary is analysed for the largest rivers in the basin. In a second step, a classification of the proportionality between in situ and GRACE time-series is proposed.

Numerical simulation of the reflow soldering process

Dissertação de mestrado integrado em Mechanical Engineering