Avaliação experimental do comportamento dinâmico de um edifício do século XIX: aplicação à calibração de modelos numéricos

Trabalho de Dissertação de natureza científica para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Estruturas

Estudo numérico e experimental sobre o comportamento dinâmico de um edifício

Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Estruturas

Dimensionamento de estacas baseado nos princípios da dinâmica de cravação do SPT

Este trabalho insere-se no domínio da calibração energética dos equipamentos SPT, dando seguimento ao disposto na norma EN ISO 22476-3, de aplicação obrigatória em Portugal. Para tal foi utilizada uma vara instrumentada, cuja instrumentação consiste em strain-gauges e acelerómetros piezoeléctricos. Esta instrumentação encontra-se fixa a um trecho de vara com comprimento de 60 cm e para a aquisição dos dados foi utilizado o sistema SPT Analyzer® comercializado pela firma PDI. O sistema permite registar os dados provenientes da instrumentação: sinais de um par de strain-gauges, transformados em registos de força (F1 e F2) e sinais de um par de acelerómetros, convertidos em registos de velocidade (V1 e V2) ao longo do tempo. O equipamento permite a avaliação, em tempo real, da qualidade dos registos e da energia máxima transmitida à vara em cada golpe e o conhecimento do deslocamento vertical do trem de varas ocorrido em cada golpe do martelo. Por outro lado, baseando-se no tema acima referido, pretende-se ainda desenvolver esforços no sentido de melhorar o novo método interpretativo dos resultados dos ensaios SPT e sua aplicação ao dimensionamento de estacas, dado que a previsão da capacidade de carga de estacas constitui um dos desafios da engenharia de fundações por requerer a estimativa de propriedades do solo, alterações pela execução da fundação e conhecimento do mecanismo de interacção solo-estaca. Este novo procedimento baseia-se nos princípios da dinâmica, rompendo com as metodologias até aqui consagradas, de natureza essencialmente empírica. A nova forma de interpretar os ensaios SPT, consubstanciada nos princípios de conservação de energia na cravação do amostrador SPT, irá permitir converter analiticamente o valor Nspt numa força dinâmica de reacção à penetração. A decomposição desta força dinâmica permite efectuar análises comparativas entre as resistências unitárias mobilizadas no amostrador SPT (modelo) e as mobilizadas na estaca (protótipo).

Performance of a Brazilian population on the test of functional health literacy in adults

OBJECTIVE: To analyze the scoring obtained by an instrument, which evaluates the ability to read and understand items in the health care setting, according to education and age. METHODS: The short version of the Test of Functional Health Literacy in Adults was administered to 312 healthy participants of different ages and years of schooling. The study was conducted between 2006 and 2007, in the city of São Paulo, Southeastern Brazil. The test includes actual materials such as pill bottles and appointment slips and measures reading comprehension, assessing the ability to read and correctly pronounce a list of words and understand both prose passages and numerical information. Pearson partial correlations and a multiple regression model were used to verify the association between its scores and education and age. RESULTS: The mean age of the sample was 47.3 years(sd=16.8) and the mean education was 9.7 years(sd=5; range: 1 - 17). A total of 32.4% of the sample showed literacy/numeracy deficits, scoring in the inadequate and marginal functional health literacy ranges. Among the elderly (65 years or older) this rate increased to 51.6%. There was a positive correlation between schooling and scores (r=0.74; p<0.01) and a negative correlation between age and the scores (r=-0.259; p<0.01). The correlation between the scores and age was not significant when the effects of education were held constant (rp=-0.031, p=0.584). A significant association (B=3.877, Beta =0.733; p<0.001) was found between schooling and scores. Age was not a significant predictor in this model (B=-0.035, Beta=-0.22; p=0.584). CONCLUSIONS: The short version of the Test of Functional Health Literacy in Adults was a suitable tool to assess health literacy in the study population. The high number of individuals classified as functional illiterates in this test highlights the importance of special assistance to help them properly understand directions for healthcare.

Development of triplet repeat primed PCR (TP-PCR) technique as a support of molecular test in Machado-Joseph disease

Dissertação de Mestrado, Ciências Biomédicas, 3 de Fevereiro de 2016, Universidade dos Açores.

Development of TNBS-induced colitis: animal model to test new pharmacological approaches

IBD is a gastro-intestinal disorder marked with chronic inflammation of intestinal epithelium, damaging mucosal tissue and manifests into several intestinal and extra-intestinal symptoms. Currently used medical therapy is able to induce and maintain the patient in remission, however no modifies or reverses the underlying pathogenic mechanism. The research of other medical approaches is crucial to the treatment of IBD and, for this, it´s important to use animal models to mimic the characteristics of disease in real life. The aim of the study is to develop an animal model of TNBS-induced colitis to test new pharmacological approaches. TNBS was instilled intracolonic single dose as described by Morris et al. It was administered 2,5% TNBS in 50% ethanol through a catheter carefully inserted into the colon. Mice were kept in a Tredelenburg position to avoid reflux. On day 4 and 7, the animals were sacrificed by cervical dislocation. The induction was confirmed based on clinical symptoms/signs, ALP determination and histopathological analysis. At day 4, TNBS group presented a decreased body weight and an alteration of intestinal motility characterized by diarrhea, severe edema of the anus and moderate morbidity, while in the two control groups weren’t identified any alteration on the clinical symptoms/signs with an increase of the body weight. TNBS group presented the highest concentrations of ALP comparing with control groups. The histopathology analysis revealed severe necrosis of the mucosa with widespread necrosis of the intestinal glands. Severe hemorrhagic and purulent exsudates were observed in the submucosa, muscular and serosa. TNBS group presented clinical symptoms/signs and histopathological features compatible with a correct induction of UC. The peak of manifestations became maximal at day 4 after induction. This study allows concluding that it’s possible to develop a TNBS induced colitis 4 days after instillation.

Linking entrepreneural orientation to export performance: the role of intangible resources and dynamic capabilities

Understanding the determinants of international performance, and in particular, export performance is key for the success of international companies. Research in this area focuses mainly on how resources and capabilities allow companies to gain competitive advantage and superior performance in external markets. Building on the Resource-Based View (RBV) and the Dynamic Capabilities Approach (DCA), this study aims at analysing the effect of intangible resources and capabilities on export performance. Specifically, this study focuses on the proposition that entrepreneurial orientation potentiates the attraction of intangible resources, namely relational and informational resources. Moreover, we propose that these resources impact export performance both directly and indirectly through dynamic capabilities.

Do the most productive firms become exporters? Application of a test for the case of Portugal

Using a longitudinal database (1996-2003) at the plant level, this article aims to shed light on the proposition that most productive domestic firms self-select to export markets. Self-selection and learning by exporting are two non-mutually-exclusive theses that attempt to explain the high correlation between firms’ international trade involvement and their superior performance relative to domestic firms. In general, we find evidence of a self-selection to exports. However, there is significant heterogeneity of sales destinations, firm import status before exporting,and the specificities of the sectors firms belong to.

Psychiatric patients' return for HIV/STI test results in mental health centers

OBJECTIVE: To assess individual and/or health service factors associated with patients returning for results of HIV or sexually transmitted infection (STI) tests in mental health centers. METHODS: Cross-sectional national multicenter study among 2,080 patients randomly selected from 26 Brazilian mental health centers in 2007. Multilevel logistic regression was used to assess the effect of individual (level 1) and mental health service characteristics (level 2) on receipt of test results. RESULTS: The rate of returning HIV/STI test results was 79.6%. Among health service characteristics examined, only condom distribution was associated with receiving HIV/STI test results, whereas several individual characteristics were independently associated including living in the same city where treatment centers are; being single; not having heard of AIDS; and not having been previously HIV tested. CONCLUSIONS: It is urgent to expand HIV/STI testing in health services which provide care for patients with potentially increased vulnerability to these conditions, and to promote better integration between mental health and health services.

Avaliação da influência dos estímulos alimentares na actividade extracardíaca

Mestrado em Medicina Nuclear - Ramo de especialização: Radiofarmácia

Evaluation of dynamic pass-through of carbon prices into electricity prices – a cointegrated VECM analysis

This paper addresses the impact of the CO2 opportunity cost on the wholesale electricity price in the context of the Iberian electricity market (MIBEL), namely on the Portuguese system, for the period corresponding to the Phase II of the European Union Emission Trading Scheme (EU ETS). In the econometric analysis a vector error correction model (VECM) is specified to estimate both long–run equilibrium relations and short–run interactions between the electricity price and the fuel (natural gas and coal) and carbon prices. The model is estimated using daily spot market prices and the four commodities prices are jointly modelled as endogenous variables. Moreover, a set of exogenous variables is incorporated in order to account for the electricity demand conditions (temperature) and the electricity generation mix (quantity of electricity traded according the technology used). The outcomes for the Portuguese electricity system suggest that the dynamic pass–through of carbon prices into electricity prices is strongly significant and a long–run elasticity was estimated (equilibrium relation) that is aligned with studies that have been conducted for other markets.

Dynamic QoS-Aware coalition formation

Users of wireless devices increasingly demand access to multimedia content with speci c quality of service requirements. Users might tolerate di erent levels of service, or could be satis ed with di erent quality combinations choices. However, multimedia processing introduces heavy resource requirements on the client side. Our work tries to address the growing demand on resources and performance requirements, by allowing wireless nodes to cooperate with each other to meet resource allocation requests and handle stringent constraints, opportunistically taking advantage of the local ad-hoc network that is created spontaneously, as nodes move in range of each other, forming a temporary coalition for service execution. Coalition formation is necessary when a single node cannot execute a speci c service, but it may also be bene cial when groups perform more e ciently when compared to a single s node performance.

Laxity dynamics and LLF schedulability analysis on multiprocessor platforms

LLF (Least Laxity First) scheduling, which assigns a higher priority to a task with a smaller laxity, has been known as an optimal preemptive scheduling algorithm on a single processor platform. However, little work has been made to illuminate its characteristics upon multiprocessor platforms. In this paper, we identify the dynamics of laxity from the system’s viewpoint and translate the dynamics into LLF multiprocessor schedulability analysis. More specifically, we first characterize laxity properties under LLF scheduling, focusing on laxity dynamics associated with a deadline miss. These laxity dynamics describe a lower bound, which leads to the deadline miss, on the number of tasks of certain laxity values at certain time instants. This lower bound is significant because it represents invariants for highly dynamic system parameters (laxity values). Since the laxity of a task is dependent of the amount of interference of higher-priority tasks, we can then derive a set of conditions to check whether a given task system can go into the laxity dynamics towards a deadline miss. This way, to the author’s best knowledge, we propose the first LLF multiprocessor schedulability test based on its own laxity properties. We also develop an improved schedulability test that exploits slack values. We mathematically prove that the proposed LLF tests dominate the state-of-the-art EDZL tests. We also present simulation results to evaluate schedulability performance of both the original and improved LLF tests in a quantitative manner.

Dynamic global scheduling of parallel real-time tasks

High-level parallel languages offer a simple way for application programmers to specify parallelism in a form that easily scales with problem size, leaving the scheduling of the tasks onto processors to be performed at runtime. Therefore, if the underlying system cannot efficiently execute those applications on the available cores, the benefits will be lost. In this paper, we consider how to schedule highly heterogenous parallel applications that require real-time performance guarantees on multicore processors. The paper proposes a novel scheduling approach that combines the global Earliest Deadline First (EDF) scheduler with a priority-aware work-stealing load balancing scheme, which enables parallel realtime tasks to be executed on more than one processor at a given time instant. Experimental results demonstrate the better scalability and lower scheduling overhead of the proposed approach comparatively to an existing real-time deadline-oriented scheduling class for the Linux kernel.

PV system modeling by five parameters and in situ test

This paper focuses on a novel formalization for assessing the five parameter modeling of a photovoltaic cell. An optimization procedure is used as a feasibility problem to find the parameters tuned at the open circuit, maximum power, and short circuit points in order to assess the data needed for plotting the I-V curve. A comparison with experimental results is presented for two monocrystalline PV modules.