Desenvolvimento de um Sistema de Apoio à Decisão para a Manutenção Preditiva dos ativos de uma Subestação Elétrica

Numa empresa como a EDP Distribuição, a ocorrência de falhas nos ativos de um Subestação pode ter consequências graves. Os equipamentos próximos podem também ser afetados e podem até causar cortes de energia afetando os consumidores.A EDP Distribuição desenvolveu algoritmos para cálculo de estimativas: (1) do Índice de Vida, (2) da Probabilidade de Falha e (3) do tempo de vida restante dos principais ativos de uma Subestação. Estas métricas podem dar uma perspetiva clara e facilmente compreensível do estado do ativo e ajudar no processo de manutenção de uma rede de Subestações.O algoritmo tem vários parâmetros provenientes de diferentes fontes de informação como testes de diagnóstico, inspeções de rotina ou monitorização online, o que faz com que seja difícil aplicar este algoritmo a todas as Subestações. No trabalho desenvolvido criou-se uma plataforma protótipo onde, de modo simples e, compilando toda a informação disponível, se cria um Sistema de Apoio à Decisão que calcula os indicadores referidos e apresenta-os de uma forma prática e intuitiva. Através desta aplicação, um operador tem acesso a uma rede de Subestações e pode facilmente verificar a condição dos ativos de cada uma das Subestações.São também estudadas diferentes aplicações potenciais de algoritmos de Data Mining para detetar padrões nos dados existentes e providenciar informação valiosa para o planeamento de manutenção. Para o caso específico da estimação da Probabilidade de Falha foram testados diferentes métodos que permitiram melhorar as previsões dadas pelo algoritmo previamente existente na empresa.O objetivo final é auxiliar a transição de um modelo de manutenção baseado no tempo para um modelo de manutenção preditivo das Subestações, fornecendo a informação necessária para aplicar medidas preventivas antes que uma falha ocorra.In a company like EDP Distribuição, the occurrence of faults in a Substation's assets can have dire consequences. It may cause damages to the surrounding equipment and ultimately cause power outages affecting the consumers.EDP Distribuição has developed algorithms to calculate an estimation of: (1) the Health Index, (2) the Failure Probability and (3) the remaining lifetime of a Substation's assets. These metrics give a clear and understandable picture of the asset's state and help in the management of a Substation network. The algorithm has various parameters from different sources like diagnostic tests, routine inspections or online monitoring, which makes it a difficult task to apply this algorithm to all the Substations. A prototype of a Decision Support System was implemented, it uses the necessary inputs to calculate the referred metrics and present them in an understandable and practical way. Using this application, an operator has access to a subset of the network of Substations and can easily check the condition of each Substation's assets. Different potential applications of Data Mining algorithms are also studied to detect patterns in the existing data and provide valuable inputs to the maintenance planning. To the specific case of estimating the Failure Probability various methods were tested and they were able to improve the predictions made by the algorithm created in the company.The final goal is to allow a move from time-based maintenance to a predictive maintenance of the Substations, giving the information needed to apply preventive measures before a fault occurs

Childhood Obesity and Impact on the Kidney

Obesity is known to be associated with a myriad of cardiovascular and metabolic comorbidities. In children, several longitudinal studies have shown that obesity consequences start early in life and accompany the obese child into adulthood, implying a higher risk of adverse cardiovascular events. More recently, data related to the possible role of obesity in the risk of kidney disease in adults, independently of diabetes, has started to become more available. In children, the evidence is scarcer, but it has also been acknowledged that obesity acts as a risk factor for disease progression when kidney impairment already exists, thereby increasing the risk of death among children with end-stage renal disease (ESRD). Besides this, there is also evidence that otherwise healthy overweight and obese children have a significant increase in the risk of all-cause ESRD later in life. The potential mechanisms underlying this association need to be further discussed in order to allow the setting in motion of preventive strategies to halt chronic kidney disease development and progression

Orohanditest: A new method for orofacial damage assessment

Background: Currently, orofacial sequelae are recognized as very influential on the quality-of-life for a victim of orofacial damage. Therefore, correct forensic assessment for indenisation purposes is mandatory. However, orofacial damage is frequently reduced to organic components, which results in a forensic assessment process, which are inadequate. This study aims to improve the orofacial damage assessment through the development of an auxiliary tool, the orohanditest. Materials and Methods: A preliminary inventory was constructed, using relevant bibliographic elements and retrospective study of forensic examinations reports concerning orofacial trauma. This inventory was then utilized in the assessment of 265 orofacial trauma victims for validation. Validity was studied by analyzing the internal construct validity (exploring factorial validity and assessing internal consistency) and the external construct validity (assessing convergent validity and discriminant validity). The level of significance was defined as P < 0.05. Results: The final inventory (orohanditest) was comprised of the three components of body (8 items), functions (10 items) and situations (24 items), which were found to be statistically reliable and valid for assessment. The final score (orofacial damage coefficient) reflects the orofacial damage severity. Conclusion: Orohanditest provides a reliable, precise, and complete orofacial damage description and quantification. Therefore, this method can be useful as an auxiliary tool in the orofacial damage assessment process

Incentivos financeiros no apoio a PMEs : uma análise aos processos de candidatura e execução de investimentos

O sistema de incentivos financeiros, doravante designado por SIF, desempenha um papel de suporte ao investimento das PMEs, complementando as fontes de financiamento externo convencionais (financiamento bancário, capital próprio). Desta forma, torna-se importante garantir a máxima eficiência deste programa de apoio do estado, de forma a responder às necessidades apresentadas pelos empresários. O objetivo deste relatório passa por responder às seguintes questões: 1. Existem constrangimentos enfrentados pelas PMEs no acesso ao SIF? Se sim, quais? 2. A avaliação dos processos de candidatura no âmbito do SIF segue uma lógica financeira? A abordagem utilizada incide num conjunto de quatro procedimentos, todos eles interligados. Primeiramente, realizou-se um conjunto de reuniões internas com os colaboradores da FI Group, de forma a perspetivar as potenciais fragilidades que advêm da execução dos processos de candidatura e de acompanhamento dos projetos. Em segundo lugar, procedeu-se a uma análise empírica das condições de acesso e dos referenciais de nível de mérito, de três tipologias do sistema de incentivos financeiros. Em terceiro lugar, foi formulado um conjunto de hipóteses de pesquisa, que enaltecem potenciais fragilidades associadas à atual implementação do sistema de incentivos financeiros. Por último, realizou-se um questionário que foi enviado para os clientes da empresa, de forma a testar as hipóteses delineadas. Os resultados permitiram concluir que: 1. Existem constrangimentos enfrentados pelas PMEs no acesso aos SIF, nomeadamente no que concerne à tempestividade do reembolso das despesas, e à dificuldade e falta de atratividade na obtenção de financiamento bancário. 2. A avaliação dos processos de candidatura no âmbito do SIF apresentam uma lógica financeira pobre, sendo que existe falta de instrumentos de avaliação financeira, não sendo a avaliação atual devidamente fundamentada, podendo não refletir o devido valor dos projetos de investimento.The financial incentives system, hereafter referred to as FIS, plays a supporting role in SME investment, complementing the main sources of external financing (bank financing and equity). Thus, it is important to ensure the maximum efficiency of this support programme, to respond to the needs presented by entrepreneurs. The aim of this report is to respond to the following questions: 1. Are there constraints faced by SMEs in accessing the FIS? If so, which ones? 2. Does the valuation of the application processes under the FIS follow a financial logic? The approach used focuses on a set of four procedures, all of which are interlinked. Firstly, a series of internal meetings were held with FI Group staff to gain an insight into potential weaknesses in the implementation of the application and project monitoring processes. Next, an empirical analysis of the access conditions and merit level benchmarks of three typologies of the financial incentives system was carried out. Third, the formulation of a set of research hypotheses was performed, that highlight potential weaknesses associated with the current implementation of the financial incentives system. Finally, a questionnaire was drawn up and sent to the company's clients to test the outlined hypotheses. Once the results were analysed, it was concluded that: 1. There are constraints faced by SMEs that arise from the formulation of the FIS, namely when it comes to the timing of the reimbursement of the expenses, and due to the difficulty and lack of attractiveness in obtaining bank financing. 2. The valuation of the application processes under the FIS presents a poor financial logic, due to the lack of financial valuation tools, and the current evaluation is not properly grounded and may not reflect the true value of the investment projects

Acidose metabólica crónica de causa renal e crescimento

Dissertação de Doutoramento em Medicina, área de especialização em Pediatria, apresentada à Faculdade de Medicina da Universidade do Port

Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population

Objectives: The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Study Design: Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. Results: The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. Conclusions: This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique

Impact of physical activity on redox status and nitric oxide bioavailability in nonoverweight and overweight/obese prepubertal children

Nutritional status might contribute to variations induced by physical activity (PA) in redox status biomarkers. We investigated the influence of PA on redox status and nitric oxide (NO) production/metabolism biomarkers in nonoverweight and overweight/obese prepubertal children. We performed a cross-sectional evaluation of 313 children aged 8-9 years (163 nonoverweight, 150 overweight/obese) followed since birth in a cohort study (Generation XXI, Porto, Portugal). Plasma total antioxidant status (P-TAS), plasma and urinary isoprostanes (P-Isop, U-Isop), urinary hydrogen peroxide (U-H2O2), myeloperoxidase (MPO) and plasma and urinary nitrates and nitrites (P-NOx, U-NOx) were assessed, as well as their association with variables of reported PA quantification (categories of PA frequency (>1x/week and ≤1x/week)and continuous PA index (obtained by the sum of points)) in a questionnaire with increasing ranks from sedentary to vigorous activity levels. U-NOx was significantly higher in children who presented higher PA index scores and higher PA frequency. Separately by BMI classes, U-NOx was significantly higher only in nonoverweight children who practiced PA more frequently (p = 0.037). In overweight/obese children, but not in nonoverweight, P-TAS was higher among children with higher PA frequency (p = 0.007). Homeostasis model assessment index (HOMA-IR) was significantly lower in more active overweight/obese children, but no differences were observed in nonoverweight children. In the fully adjusted multivariate linear regression models for P-TAS, in the overweight/obese group, children with higher PA frequency presented higher P-TAS. In the U-NOx models, U-NOx significantly increased with PA index, only in nonoverweight children. Our results provide additional evidence in support of a protective effect of physical activity, in nonoverweight by increasing NO bioavailability and in overweight/obese children by enhancing systemic antioxidant capacity and insulin sensitivity. These results highlight the importance of engaging in regular physical exercise, particularly among overweight/obese children, in which a positive association between oxidant status and cardiometabolic risk markers has been described.This project was supported by FEDER funds from Programa Operacional Factores de Competitividade – COMPETE [FCOMP-01-0124-FEDER-028751], by national funds from the Portuguese Foundation for Science and Technology (FCT), Lisbon, Portugal [PTDC/DTP-PIC/0239/2012] and by Calouste Gulbenkian Foundation. Liane Correia-Costa was supported by FCT [SFRH/SINTD/95898/2013] and Teresa Sousa was supported by FCT and POPH/FSE (EC) [Ciência 2008 and SFRH/BPD/112005]

ENTRE A AUTONOMIA E A HETERONOMIA DA VONTADE NAS RELAÇÕES CONTRATUAIS

O presente artigo analisa o instituto da autonomia da vontade como referencial para o negócio jurídico. Isso se dá, na perspectiva da pesquisa, quanto àquilo quanto possível para aproximar o Direito do Trabalho e o Direito Civil no que tange a matéria de contratos que é posterior à autonomia da vontade de contratar

Chronology of mineralization of the permanent mandibular second molar teeth and forensic age estimation

Forensic age estimation frequently relies upon the chronology of mineralization of the third molar teeth. However, even when present, third molar teeth cannot always be used for estimating age in people who are classified as minors. Seconds molars develop earlier and in a more predictable way, and therefore are often more reliable for age estimation in this age group. This study aims to contribute to forensic age estimation using an age threshold of 14-years, studying the stages of development of permanent mandibular second molar teeth mineralization. 367 orthopantograms of a Portuguese population group, aged between 3 and 19 years, were studied. The stages of mineralization of mandibular permanent second molar teeth were studied following the classification stages proposed by Demirjian et al. Stage descriptive analysis was performed, and associations between age and stage were studied.A logistic regression to determine age over 14 years, using maturation stages and sex as a predictive variables, was made. A second sample was used for testing the model. The significance level was set at 5%. The model correctly classified 92.0% of cases overall. The equation was tested in the second sample, and the results showed that there were no statistical significant differences between the binary real age (i.e. age < 14 and age ≥ 14 years) and the estimated age (p = 0.109). The developed model is useful for age estimation using 14-years as a threshold. However, stage maturation analyses showed that stage F, in males, and stages G and H, in both sexes, lead to an estimated age with significant statistical differences from chronological age