Building public policy on shifting sands: the case of the National Asset Management Agency

Over the last thirty years, there has been an increased demand for better management of public sector organisations (PSOs). This requires that they are answerable for the inputs that they are given but also for what they achieve with these inputs (Hood 1991; Hood 1995). It is suggested that this will improve the management of the organisation through better planning and control, and the achievement of greater accountability (Smith 1995). However, such a rational approach with clear goals and the means to measure achievement can cause difficulties for many PSOs. These difficulties include the distinctive nature of the public sector due to the political environment within which the public sector manager operates (Stewart and Walsh 1992) and the fact that PSOs will have many stakeholders, each of whom will have their own specific objectives based on their own perspective (Boyle 1995). This can
result in goal ambiguity which means that there is leeway in interpreting the results of the PSO. The National Asset Management Agency (NAMA) was set up to bring stability to the financial system by buying loans from the banks (which were in most cases, non-performing loans). The intention was to cleanse the banks of these loans so that they could return to their normal business of taking deposits and making loans. However, the legislation, also gave NAMA a wide range of other responsibilities including responsibility for facilitating credit in the economy and protecting the interests of taxpayers. In more recent times, NAMA has been given responsibility for building social housing. This wide-range of activities is a clear example of a PSO being given multiple goals which may conflict and is therefore likely to lead to goal ambiguity. This makes it very difficult to evaluate NAMA’s performance as they are attempting to meet numerous goals at the same time and also highlights the complexity of policy making in the public sector. The purpose of this paper is to examine how NAMA dealt with goal ambiguity. This will be done through a thematic analysis of its annual reports over the last five years. The paper’s will contribute to the ongoing debate about the evaluation of PSOs and the complex environment within which they operate which makes evaluation difficult as they are
answerable to multiple stakeholders who have different objectives and different criteria for measuring success.

Fiducial Marker Guided Prostate Radiotherapy: A Review

Image guided radiotherapy (IGRT) is an essential tool in the accurate delivery of modern radiotherapy techniques. Prostate radiotherapy positioned using skin marks or bony anatomy may be adequate for delivering a relatively homogenous whole pelvic radiotherapy dose but these are not reliable when using reduced margins, dose escalation or hypo-fractionated stereotactic radiotherapy. Fiducial markers (FMs) for prostate IGRT have been in use since the 1990's. They require surgical implantation and provide a surrogate for the position of the prostate gland. A variety of FMs are available and they can be used in a number of ways. This review aims to establish the evidence for using prostate FMs in terms of feasibility, implantation procedures, types of FMs used, FM migration, imaging modalities used and the clinical impact of FMs. A search strategy was defined and a literature search was carried out in Medline. Inclusion and exclusion criteria were applied which resulted in 50 papers being included in this review. The evidence demonstrates that FMs provide a more accurate surrogate for the position of the prostate than either external skin marks or bony anatomy. A combination of FM alignment and soft tissue analysis is currently the most effective and widely available approach to ensuring accuracy in prostate IGRT. FM implantation is safe and well tolerated. FM migration is possible but minimal. Standardisation of all techniques and procedures in relation to the use of prostate FMs is required. Finally a clinical trial investigating a non-surgical alternative to prostate FMS is introduced.

Antimicrobial susceptibility of Pseudomonas aeruginosa isolated from cystic fibrosis patients through Northern Europe

Pseudomonas aeruginosa is a major cause of morbidity and mortality in cystic fibrosis patients. This study compares the antimicrobial susceptibility of 153 P. aeruginosa isolates from the United Kingdom (UK) (n=58), Belgium (n=44), and Germany (n=51) collected from 120 patients during routine visits over the 2006-2012 period. MICs were measured by broth microdilution. Genes encoding extended spectrum β-lactamases (ESBL), metallo-β-lactamases and carbapenemases were detected by PCR. Pulsed Field Gel Electrophoresis and Multi-Locus Sequence Typing were performed on isolates resistant to ≥ 3 antibiotic classes among penicillins/cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, polymyxins. Based on EUCAST/CLSI breakpoints, susceptibility was ≤ 30%/≤ 40% (penicillins, ceftazidime, amikacin, ciprofloxacin), 44-48%/48-63% (carbapenems), 72%/72% (tobramycin), and 92%/78% (colistin) independently of patient's age. Sixty percent of strains were multidrug resistant (MDR; European Centre for Disease prevention and Control criteria). Genes encoding ESBL (most prevalent BEL, PER, GES, VEB, CTX-M, TEM, SHV, and OXA), metallo β-lactamases (VIM, IMP, NDM), or carbapenemases (OXA-48, KPC) were not detected. The Liverpool Epidemic Strain (LES) was prevalent in UK isolates only (75% of MDR isolates). Four MDR ST958 isolates were found spread over the three countries. The other MDR clones were evidenced in ≤ 3 isolates and localized in a single country. A new sequence type (ST2254) was discovered in one MDR isolate in Germany. Clonal and non-clonal isolates with different susceptibility profiles were found in 21 patients. Thus, resistance and MDR are highly prevalent in routine isolates from 3 countries, with carbapenem (meropenem), tobramycin and colistin remaining the most active drugs.

Förekomst av sekundär traumatisk stress hos sjuksköterskor och dess påverkan på personcentrerad vård : - En litteraturstudie

Bakgrund: Sjuksköterskan har stor del i den nära patientvården och förväntas vara en god lyssnare genom sitt personcentrerade vårdgivande. Händelser som är traumatiska drabbar förutom den direkt berörda patienten även sjuksköterskan genom sekundär exponering. Syfte: Syftet med studien var att belysa förekomst av STS hos sjuksköterskor samt beskriva hur det påverkar vårdkvalitet och personcentrerad vård. Metod: Litteraturstudie med en översikt av relevanta artiklar i databaserna PubMed och CINAHL. Resultatet baseras på 14 artiklar som uppfyllde inklusionsoch kvalitetskrav. Resultat: Sjuksköterskan påverkas av STS på flera plan, både professionellt och personligt. Vårdkvaliteten blir lidande om STS påvisas. Den personcentrerade vården utgör grunden i sjuksköterskans yrkesutövande men om medvetenhet saknas för STS finns risken att sjuksköterskan påverkas så till den grad att hen väljer att sjukskriva sig och/eller byta arbetsplats. Slutsats: STS är ett relativt okänt begrepp och det kan vara svårt att se tecken på begynnande symtom. Sjuksköterskan kan utsättas för STS oberoende arbetsplats. Detta kan sänka effekten i yrkesutövandet genom personliga symtom som; irritabilitet, trötthet, minskad empati, depression, återupplevelser av tidigare upplevda traumatiska händelser med flera. Arbetsplatsens ledarskap inverkar på identifieringen av sjuksköterskans utveckling/hanterande av STS.

Influence des traits et troubles de personnalité sur l’intégration au travail de personnes aux prises avec un trouble mental grave

Bien que le travail soit bénéfique et souhaité par une majorité de personnes aux prises avec un trouble mental grave (TMG), les études réalisées auprès de cette clientèle montrent des taux d’emploi d’environ 10 à 20%. Parmi les services visant le retour au travail, les programmes de soutien à l’emploi (PSE) se sont montrés les plus efficaces avec des taux de placement en emploi standard oscillant entre 50 et 60%, sans toutefois garantir le maintien en emploi. Plusieurs études ont tenté de cerner les déterminants de l’obtention et du maintien en emploi chez cette population sans toutefois s’intéresser à la personnalité, et ce, bien qu’elle soit reconnue depuis toujours comme un déterminant important du fonctionnement des individus. De plus, peu de questionnaires d’évaluation de la personnalité selon le modèle de la personnalité en cinq facteurs (FFM) ont été utilisés auprès d’une clientèle avec un TMG et ceux-ci ont montré des propriétés psychométriques ne respectant pas des normes reconnues et acceptées. Cette thèse porte sur les liens entre la personnalité et l’intégration au travail chez les personnes avec un TMG. La première partie vise la validation d’un outil de mesure de la personnalité selon le FFM afin de répondre aux objectifs de la deuxième partie de la thèse. À cet effet, deux échantillons ont été recrutés, soit 259 étudiants universitaires et 141 personnes avec un TMG. Des analyses factorielles confirmatoires ont mené au développement d’un nouveau questionnaire à 15 items (NEO-15) dont les indices d’ajustement, de cohérence interne et de validité convergente respectent les normes établies, ce qui en fait un questionnaire bien adapté à la mesure de la personnalité normale dans des contextes où le temps d’évaluation est limité. La deuxième partie présente les résultats d’une étude réalisée auprès de 82 personnes aux prises avec un TMG inscrites dans un PSE et visant à identifier les facteurs d’obtention et de maintien en emploi chez cette clientèle, particulièrement en ce qui concerne la contribution des éléments normaux et pathologiques de la personnalité. Les résultats de régressions logistiques et de régressions de Cox (analyses de survie) ont démontré que l’historique d’emploi, les symptômes négatifs et le niveau de pathologie de la personnalité étaient prédictifs de l’obtention d’un emploi standard et du délai avant l’obtention d’un tel emploi. Une autre série de régressions de Cox a pour sa part démontré que l’esprit consciencieux était le seul prédicteur significatif du maintien en emploi. Malgré certaines limites, particulièrement des tailles d’échantillons restreintes, ces résultats démontrent la pertinence et l’importance de tenir compte des éléments normaux et pathologiques de la personnalité dans le cadre d’études portant sur l’intégration au travail de personnes avec un TMG. De plus, cette thèse a permis de démontrer l’adéquation d’un nouvel instrument de mesure de la personnalité auprès de cette clientèle. Des avenues futures concernant la réintégration professionnelle et le traitement des personnes avec un TMG sont discutées à la lumière de ces résultats.

Fingolimod real world experience

Fingolimod is a Multiple Sclerosis treatment licensed in Europe since 2011. Its efficacy has been demonstrated in three large phase III trials, used in the regulatory submissions throughout the world. As usual, in these trials the inclusion and exclusion criteria were designed to obtain a homogeneous population, with interchangeable characteristics in the different treatment arms. Although this is the best strategy to achieve a robust answer to the investigation question, it does not guaranty the treatment efficacy in the clinical practice, since in the real world there are concomitant treatments, comorbidities, adherence and persistence challenges. But, to make informed treatment decision for a real life patient, we need to have evidence of the treatment efficacy, what has been called treatment effectiveness. This work aims to review fingolimod effectiveness, using as source of information abstracts, posters and manuscripts. This unorthodox strategy was developed because more than half of the published experience with fingolimod is still on abstracts and posters. Only a small part of the studies reviewed are already published in peer reviewed journals. Fingolimod seems to be, at least, as effective and safe as it was on clinical trials, and with its long term experience no new safety signals were observed. In the Portuguese hospital perspective, early treatment with fingolimod is expected to result in better clinical outcomes associated with a more efficient healthcare resources allocation.

Parente sensitive support by paediatric nurses

Introdução The hospitalization of a child is an experience that causes big changes in child and his family life. The parents often suffer from stress and anxiety. This can affect their relationship with the child. Because of the closeness to the parents, nurses have an important role in giving parents support so they can reduce their stress and have more energy to support and take care of their children and in the inclusion of the family in the process of care Objectivos The aim of this study was to define what family-centered care is, to define the needs of hospitalized children's parents and to identify the strategies and methods that the nurses use to give parental support adapted to the parent's needs. It was also a goal to identify and understand the main differences between parental support given by nurses in Belgium and Portugal. Metodologia The study exists out of two parts. First is an integrative review of literature. The search was performed using the databases MEDLINE, CINAHL , PubMed and Science Direct. 18 Articles were selected based on inclusion and exclusion criteria. They had to involve nurses, hospitalized children between 0 and 18 years and their parents. Second part was a focus group. The participants were pediatric nurses from Portugal and Belgium. The goal was to understand different perspectives related to the parental needs of hospitalized children and nursing interventions to answer that needs. Resultados family-centered care can be considered as a partnership between family and nurses. It has some general principles: information sharing, respect differences, negotiation and care in the context of the family. Parent's participation is important to reduce the parental stress and it is essential for meeting the needs of the children. Parents have different needs: knowledge and communication, support, comfort, proximity and assurance. Parents cope with stress in different ways and nurses can support them while they are in the hospital. It is a nurse task to identify the stressors and know methods of emotional support, so she can protect the family structure. Nurses should always see the family as a path to the child, with whom the nurses should worry about taking care and meeting their needs. This is crucial to ensure the family's well-being, adaption to hospitalization and the child's recovery. Conclusões Nurses should collect information about the family which includes family relationships, cultural and religious habits and familiar dynamic. Parents need interpersonal emotional support. It is important for parents to be close to their children but they also need to take care of themselves. When nurses have enough information they can use it to the identification of parental needs and the planning of nursing interventions. It is important that nurses create an environment where parents feel safe and that they have privacy. To create a therapeutic and professional relationship efficient communication is needed. Parents will experience less stress and anxiety.

Cooperativa habitacional autofinanciável :uma alternativa de mercado à escassez de financiamento

As an example of what happened in Brazil in the 90s, it s noticed in Natal a new system of cooperative housing production which is done by advancing the users resources selffinancing. This system comes as an alternative for the real state market performance since the end of the National Housing Bank (BNH), in 1986. Self-financed housing cooperatives play an important social role by contributing to own housing acquisition by low-income population, without, however, becoming a mechanism of social interest housing production. It is important to consider that Brazil registers a housing deficit of 6.6 million housing units (IBGE 2000/Census), which, compared to 1991, shows an increment of 21.7% to a growth rate of 2.2% a year. This deficit figure has been deepening, mainly with the end of the National Housing Bank (BNH). The self-financed cooperative housing production broadens around the Metropolitan Region of Natal (RMN) and remains as an alternative to the lack of financing in the housing / real state market. In general, the aim of this work is to analyze the role of self-financing housing cooperatives on the housing production in the RMN, in order to identify their role in the real state market, in the own housing promotion and in the housing policy. The Universe of this study is performance of four housing cooperatives - CHAF-RN, COOPHAB-RN, MULTHCOOP e CNH - that work through self-financing. It is considered here an amount of 38 undertakings launched between 1993 and 2002, including 8143 housing units. The methodology adopted consists of bibliographic, documental and field research. As a result, actions like brokerage, marketing, speculation, and the criteria to define places for undertakings and final products, show how close they are to the housing market production. As a matter of fact, this short distance explains why the self-financed cooperative production for social interest housing is still limited. This reinforces the theory that it is necessary to define and implement a subsidized housing policy to serve the low-income Brazilian population

Parente sensitive support by paediatric nurses

Introdução The hospitalization of a child is an experience that causes big changes in child and his family life. The parents often suffer from stress and anxiety. This can affect their relationship with the child. Because of the closeness to the parents, nurses have an important role in giving parents support so they can reduce their stress and have more energy to support and take care of their children and in the inclusion of the family in the process of care Objectivos The aim of this study was to define what family-centered care is, to define the needs of hospitalized children's parents and to identify the strategies and methods that the nurses use to give parental support adapted to the parent's needs. It was also a goal to identify and understand the main differences between parental support given by nurses in Belgium and Portugal. Metodologia The study exists out of two parts. First is an integrative review of literature. The search was performed using the databases MEDLINE, CINAHL , PubMed and Science Direct. 18 Articles were selected based on inclusion and exclusion criteria. They had to involve nurses, hospitalized children between 0 and 18 years and their parents. Second part was a focus group. The participants were pediatric nurses from Portugal and Belgium. The goal was to understand different perspectives related to the parental needs of hospitalized children and nursing interventions to answer that needs. Resultados family-centered care can be considered as a partnership between family and nurses. It has some general principles: information sharing, respect differences, negotiation and care in the context of the family. Parent's participation is important to reduce the parental stress and it is essential for meeting the needs of the children. Parents have different needs: knowledge and communication, support, comfort, proximity and assurance. Parents cope with stress in different ways and nurses can support them while they are in the hospital. It is a nurse task to identify the stressors and know methods of emotional support, so she can protect the family structure. Nurses should always see the family as a path to the child, with whom the nurses should worry about taking care and meeting their needs. This is crucial to ensure the family's well-being, adaption to hospitalization and the child's recovery. Conclusões Nurses should collect information about the family which includes family relationships, cultural and religious habits and familiar dynamic. Parents need interpersonal emotional support. It is important for parents to be close to their children but they also need to take care of themselves. When nurses have enough information they can use it to the identification of parental needs and the planning of nursing interventions. It is important that nurses create an environment where parents feel safe and that they have privacy. To create a therapeutic and professional relationship efficient communication is needed. Parents will experience less stress and anxiety.

O uso da imagiologia por termografia na medicina dentária

Introdução: No domínio científico da medicina dentária, a termografia é um dos temas mais recentes e que tem levado á publicação de alguns estudos. A combinação da avaliação funcional, características de fluxo sanguíneo e localização anatómica levou a um aumento de aplicações da termografia no diagnóstico clínico. Objetivo: Este trabalho teve como objetivo uma analise bibliografia existente sobre a termografia e as suas aplicações em medicina e medicina dentária, avaliar a sua utilidade no diagnóstico de patologias da área de atuação médico-dentária. Metodologia: Procedeu-se a uma pesquisa bibliográfica através da identificação de artigos publicados em bases de dados eletrónicas internacionais, PubMed, B-on e Science Direct utilizando palavras-chave e critérios de exclusão e inclusão, que permitiram fazer uma seleção prévia dos artigos a incluir ao longo deste trabalho. Resultados: Após a realização da pesquisa bibliográfica obtiveram-se 30 artigos. A partir da amostra encontrada foram excluídos 93 artigos devido à falta de correspondência do seu conteúdo ao tema proposto. Conclusão: Os resultados sugerem que a termografia é uma técnica de imagem que deteta a distribuição do calor da superfície corporal. A termografia Capta e transforma a radiação infravermelha emitida pela pele humana em imagens que refletem a dinâmica da microcirculação cutânea. A termografia é considerada como um técnica não invasiva, indolor, não ionizante, fornecendo informações quantitativas que permitem que seja uma técnica válida para o diagnóstico clinico complementar.

Implantes colocados justa cristal versus implantes sub-cristal

Introdução: A posição da colocação do implante relativamente à crista óssea tem sido discutida na comunidade científica como fator influenciador de sucesso ou insucesso. Por outro lado a perda ou preservação óssea está intrinsecamente relacionado com fatores como a seleção do sistema de implante, o tipo de implante e a sua conexão. Objetivo: Este trabalho teve como objetivo a análise da bibliografia existente que compara a colocação de implantes a nível da crista óssea (justa cristal) com a colocação de implantes abaixo da crista óssea (sub-cristal) em sinergismo com outros fatores, de forma que seja percecionada a eficácia e sucesso na seleção efetuada. Metodologia: Procedeu-se a uma pesquisa bibliográfica através da identificação de artigos publicados em bases de dados eletrónicas internacionais, PubMed, B-on e Science Direct utilizando palavras-chave e critérios de exclusão e inclusão, que permitiram fazer uma seleção prévia dos artigos a incluir ao longo deste trabalho. Resultados: Após a realização da pesquisa bibliográfica obtiveram-se 63 artigos. A partir da amostra encontrada foram excluídos 26 artigos devido à falta de correspondência do seu conteúdo ao tema proposto e 14 por se encontrarem repetidos ou sem dados comparativos. Nos 23 artigos aceites encontram-se incluídos estudos animais, elementos finitos, revisões e estudos clínicos. Conclusão: Os resultados sugerem que a colocação de implantes em sub-cristal apresenta-se como uma melhor solução na preservação da crista óssea, no entanto há que levar em conta outros fatores associados diretamente ao implante, nomeadamente, a geometria, superfície não polida do colo assim como o tipo de conexão do pilar ao implante, onde foi encontrada uma relativa evidência de melhor eficácia no que respeita à conexão do tipo “cone Morse”.

Nonlinear distortion generation mechanisms in Doherty amplifiers

Nowadays, wireless communications systems demand for greater mobility and higher data rates. Moreover, the need for spectral efficiency requires the use of non-constant envelope modulation schemes. Hence, power amplifier designers have to build highly efficient, broadband and linear amplifiers. In order to fulfil these strict requirements, the practical Doherty amplifier seems to be the most promising technique. However, due to its complex operation, its nonlinear distortion generation mechanisms are not yet fully understood. Currently, only heuristic interpretations are being used to justify the observed phenomena. Therefore, the main objective of this work is to provide a model capable of describing the Doherty power amplifier nonlinear distortion generation mechanisms, allowing the optimization of its design according to linearity and efficiency criteria. Besides that, this approach will allow a bridge between two different worlds: power amplifier design and digital pre-distortion since the knowledge gathered from the Doherty operation will serve to select the most suitable pre-distortion models.

Online MBPeT dashboard : enabling performance testing as a service in the cloud

In this thesis, tool support is addressed for the combined disciplines of Model-based testing and performance testing. Model-based testing (MBT) utilizes abstract behavioral models to automate test generation, thus decreasing time and cost of test creation. MBT is a functional testing technique, thereby focusing on output, behavior, and functionality. Performance testing, however, is non-functional and is concerned with responsiveness and stability under various load conditions. MBPeT (Model-Based Performance evaluation Tool) is one such tool which utilizes probabilistic models, representing dynamic real-world user behavior patterns, to generate synthetic workload against a System Under Test and in turn carry out performance analysis based on key performance indicators (KPI). Developed at Åbo Akademi University, the MBPeT tool is currently comprised of a downloadable command-line based tool as well as a graphical user interface. The goal of this thesis project is two-fold: 1) to extend the existing MBPeT tool by deploying it as a web-based application, thereby removing the requirement of local installation, and 2) to design a user interface for this web application which will add new user interaction paradigms to the existing feature set of the tool. All phases of the MBPeT process will be realized via this single web deployment location including probabilistic model creation, test configurations, test session execution against a SUT with real-time monitoring of user configurable metric, and final test report generation and display. This web application (MBPeT Dashboard) is implemented with the Java programming language on top of the Vaadin framework for rich internet application development. The Vaadin framework handles the complicated web communications processes and front-end technologies, freeing developers to implement the business logic as well as the user interface in pure Java. A number of experiments are run in a case study environment to validate the functionality of the newly developed Dashboard application as well as the scalability of the solution implemented in handling multiple concurrent users. The results support a successful solution with regards to the functional and performance criteria defined, while improvements and optimizations are suggested to increase both of these factors.

Contribuição para o conhecimento da geologia do Grupo das Beiras (CXG) na região do Caramulo-Buçaco, Portugal Central

O presente trabalho ocupa-se do estudo do Complexo Xisto-Grauváquico ante-ordovícico (Grupo das Beiras) na região do Caramulo-Buçaco (centro de Portugal). Em termos geológicos, a área estudada pertence à Zona Centro Ibérica e encontra-se limitada a N pelo granito do Caramulo, a S pela bacia meso-cenozóica de Arganil, a W pelo sinclinal paleozóico do Buçaco e pela bacia meso-cenozóica ocidental portuguesa e a E pelo sinclinal paleozóico de Arganil e pelo plutonito granítico de Tábua-Santa Comba Dão; no seio da área estudada encontra-se a bacia meso-cenozóica de Mortágua. Com base nas características litológicas e estruturais distinguem-se no Complexo Xisto Grauváquico 4 grandes conjuntos litológicos concordantes entre si, designados de Unidades I, II, III e IV, que se desenvolvem da base para o topo de N para S. A Unidade I situa-se a N da região. O seu limite inferior é desconhecido, e o superior posiciona-se no último conjunto arenoso com potência decamétrica. É constituída por xistos cinzentos e negros com intercalações de arenitos de espessura não superior a 100 metros e de extensão lateral quilométrica. Apresenta uma espessura mínima de 1000 m. A Unidade II apresenta consideravelmente menor proporção de material arenoso intercalado entre os pelitos comparativamente à unidade inferior. É caracterizada por apresentar um predomínio de material silto-argiloso e escassos níveis arenosos com potência não superior à dezena de metros e escassa continuidade lateral. Cartograficamente esta unidade constitui uma franja alargada de orientação próxima a E-W. Apresenta uma espessura aproximada de 1500 m. A Unidade III é caracterizada pela presença de conjuntos arenosos com extensão lateral quilométrica e espessura de várias dezenas de metros, separados por material silto-argiloso. Os limites inferior e superior estão situados respectivamente abaixo e acima dos principais conjuntos arenosos. Esta unidade apresenta uma espessura máxima estimada na ordem dos 2000 m. A Unidade IV, que é a unidade superior, apresenta um predomínio pelítico, com escassas intercalações de conjuntos arenosos. O seu limite inferior encontra-se no topo do último conjunto arenoso da Unidade III. Apresenta uma espessura mínima de 500 m. As características sedimentológicas das 4 unidades indicam uma sedimentação num ambiente de plataforma externa siliciclástica aberta, com a construção de barras e por vezes sujeita à acção de tempestades, com sucessivos períodos de superficialização e profundização numa bacia de sedimentação bastante subsidente. Em termos estruturais, para além duma deformação pré-ordovícica, que é comprovada pelo forte mergulho e dispersão da orientação dos eixos da 1ª fase varisca e da lineação de intersecção L1, a área estudada foi principalmente afectada pela Orogenia Varisca. A 1ª fase de deformação varisca (F1) gerou dobras com superfícies axiais e xistosidade associada (S1) de direcção WNW-ESE, e forte pendor para NNE. Estas dobras D1 apresentam comprimentos de onda que nunca chegam a ser quilométricos, desenvolvendo-se um grande flanco inverso denunciando a presença de uma antiforma para NNE e uma sinforma para SSW. A 2ª fase de deformação varisca (F2) actuou na parte nordeste da área estudada e é caracterizada por ter gerado dobras de comprimento de onda quilométrico, com planos axiais e xistosidade associada S2 de direcção NW-SE, subverticais ou a pender fortemente para NE. Embora com alguma dispersão, as lineações de intersecção L2 e os eixos das dobras D2 apresentam maioritariamente forte pendor para E. A direcção e tipos de estruturas da F2 sugerem uma correlação com a terceira fase definida em vários pontos da Zona Centro Ibérica e estreitamente relacionada com as intrusões graníticas. Do ponto de vista petrológico, distinguem-se várias rochas sedimentares (pelitos e arenitos) todas elas sujeitas a metamorfismo que não ultrapassa a fácies dos xistos verdes. Dentro das rochas sedimentares mais grosseiras, há a destacar a presença de arenitos vulcânicos cuja composição denuncia, não muito afastados da bacia sedimentar, a presença de aparelhos vulcânicos que estariam em actividade durante a sedimentação. Foram analisadas isotopicamente 27 amostras de metapelitos colhidas em 5 locais diferentes de forma a abranger quase toda a área estudada. Os dados isotópicos de quatro destes locais de amostragem forneceram isócronas Rb-Sr, em rocha total, com valores da ordem dos 400-440 Ma. O granito do Caramulo, datado pela isócrona Rb-Sr em amostras de rocha total, forneceu uma idade de 326±12Ma. As idades modelo Sm-Nd (manto empobrecido) de 5 amostras de metapelitos estão compreendidas entre 1.35 e 1.25 Ga. Este período de tempo pode ser considerado como correspondendo à época de diferenciação mantélica da crusta que deu lugar à maioria das áreas fonte dos metapelitos.

Ground fault protectionmethods for distribution systems

The system grounding method option has a direct influence on the overall performance of the entire medium voltage network as well as on the ground fault current magnitude. For any kind of grounding systems: ungrounded system, solidly and low impedance grounded and resonant grounded, we can find advantages and disadvantages. A thorough study is necessary to choose the most appropriate grounding protection system. The power distribution utilities justify their choices based on economic and technical criteria, according to the specific characteristics of each distribution network. In this paper we present a medium voltage Portuguese substation case study and a study of neutral system with Petersen coil, isolated neutral and impedance grounded.