874 resultados para Machine-tools -- Maintenance and repair
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The aims of this paper are to first seek an understanding of consumer decision-making when purchasing pension and investment products, and second to ascertain how this decision-making affects the consumer's choice of distribution route. The study employed both focus groups and postal questionnaire survey methods based on the framework of a classical decision-making model that investigated problem recognition, information search, evaluation tools used and post-purchase. The findings show that the decision-making process experience differed to a lesser or greater degree depending on the distribution route. The majority of respondents had recognised the need to make a purchase decision long before seeking information. Younger respondents on all incomes believed that they must make some pension provision for themselves as opposed to relying on the government's retirement provision. Many changed channels for information searches, but tended to settle with the Independent Financial Adviser (IFA). The two main evaluation tools for pension and investment were found to be the ‘charges’ and ‘historic fund performance’. The vast majority of respondents reiterated their worry that the outcomes would not be known until retirement. In terms of analysis by the level of ‘financial literacy’, respondents who scored in the upper quartile were more inclined to be on a higher income, less inclined to evaluate on charges and more proactive in discussing the investment strategy of their pension fund. Respondents who scored in the lower quartile had opposite results. One of the implications of these findings is that the younger respondents’ recognition of pension savings favours the government's intention to reverse the existing balance of pension distribution. The other main implication is that the findings will be of help to managers in appreciating the dominance of the IFA channel by providing an explanation of why consumers choose this route, and, additionally, can assist direct marketing managers in identifying customers who will be more likely to use multichannel or single-channel shoppers. It can also help the marketing manager increase the usage of different channels by addressing the factors driving the purchase decision and distribution choice.
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Since creation of the European Communities the number of Member States has gradually increased from the original six to current twenty-eight. Enlargement has become an EU’s flagship external policy, demonstrating the EU’s ability to shape its neighbourhood and to serve as a catalyst of deep and multilayered reforms. The consecutive seven enlargement rounds went in parallel with widespread internal developments, culminating with the creation of the European Union and, most recently, entry into force of the Treaty of Lisbon. As this volume demonstrates, EU criminal law has evolved considerably from its early days under the legal framework laid down by the Treaty of Maastricht to its current post-Lisbon shape. On 1 December 2014, that is with expiry of a five year transitional regime for the jurisdiction of the Court of Justice, Police and Judicial Co-operation in Criminal Matters became a fully fledged EU policy, governed largely by the same modus operandi as other areas of EU competence and with compulsory jurisdiction of the Court of Justice. As EU criminal law developed internally, so did its external dimension, including the role it plays in the enlargement policy. In case of the latter the expiry of the same transitional period has brought to an end a rather anomalous situation whereby the European Union had more enforcement tools before and after accession vis-à-vis its future/new Member States than it could employ against the old ones. This bifurcation, quite rightly, triggered a lot of discussions about double standards used by the European Union in its pre-accession policy. This is exacerbated by the fact that some of those standards are neither defined in EU law, nor pursued vis-à-vis the existing EU’s Member States. The aim of this chapter is to demonstrate that evolution with particular emphasis on the role of EU Criminal Law in the policy currently employed by the European Union vis-à-vis candidate and potential candidate countries of the Western Balkans and to Turkey. Arguably, together with political conditionality, it has become one of the pillars of the enlargement process and, as the examples of accession negotiations with Montenegro and Serbia prove, its role is likely to increase as rapprochement of other candidates and potential candidates progresses to the next stages.
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This paper present a methodology to choose the distribution networks reconfiguration that presents the lower power losses. The proposed methodology is based on statistical failure and repair data of the distribution power system components and uses fuzzy-probabilistic modeling for system component outage parameters. The proposed hybrid method using fuzzy sets and Monte Carlo simulation based on the fuzzyprobabilistic models allows catching both randomness and fuzziness of component outage parameters. A logic programming algorithm is applied, once obtained the system states by Monte Carlo Simulation, to get all possible reconfigurations for each system state. To evaluate the line flows and bus voltages and to identify if there is any overloading, and/or voltage violation an AC load flow has been applied to select the feasible reconfiguration with lower power losses. To illustrate the application of the proposed methodology, the paper includes a case study that considers a 115 buses distribution network.
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Trabalho Final para a obtenção do grau de Mestre em Engenharia Civil
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica
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Master Thesis in Mechanical Engineering field of Maintenance and Production
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica
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Dissertação para obtenção do grau de Mestre em Engenharia Civil - Área de Especialização de Edificações
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No presente trabalho apresenta-se um levantamento com base na literatura especializada, das diversas soluções estruturais em betão pré-fabricado existentes, aplicadas em edifícios correntes, mais especificamente as soluções ao nível dos elementos que as constituem, nomeadamente no que respeita a ligações estruturais dos elementos, com combinações in situ, das estruturas préfabricadas e as moldadas em obra, aproveitando o que de melhor se pode obter de ambas as técnicas, com vista a obter um melhor resultado final. Apesar do setor da construção civil estar em crise, tal como vários outros setores, as empresas de pré-fabricação apresentam soluções que poderão contrariar esta tendência, nomeadamente através da diversificação e flexibilização da sua produção, com inovação, criatividade e elevada qualidade. Num mercado em que a construção de edifícios de raiz sofreu um grande abrandamento, começa a surgir no mercado a necessidade de se reabilitar as construções existentes, nomeadamente nos grandes centros das cidades que foram perdendo população ao longo dos tempos. Esta requalificação do espaço urbano permite o desenvolvimento de soluções estruturais pré-fabricadas, no que respeita à reabilitação dos elementos existentes, quer por justaposição para reforço das estruturas, quer por inserção de elementos novos para efetuar correções. Os baixos custos de mão de obra, equipamentos e estaleiro, assim como a redução dos prazos de construção e entrega ao cliente final, dado que a produção não está dependente das condições existentes in situ para se desenvolver, destacam-se da construção civil tradicional. A produção integral dos elementos pré-fabricados de betão em fábrica tem outras vantagens, entre as quais, um melhor planeamento e controle da segurança, um controle rigoroso de qualidade, a redução dos custos de reparação e manutenção, melhor sustentabilidade com redução da quantidade de resíduos produzidos.
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As empresas nacionais deparam-se com a necessidade de responder ao mercado com uma grande variedade de produtos, pequenas séries e prazos de entrega reduzidos. A competitividade das empresas num mercado global depende assim da sua eficiência, da sua flexibilidade, da qualidade dos seus produtos e de custos reduzidos. Para se atingirem estes objetivos é necessário desenvolverem-se estratégias e planos de ação que envolvem os equipamentos produtivos, incluindo: a criação de novos equipamentos complexos e mais fiáveis, alteração dos equipamentos existentes modernizando-os de forma a responderem às necessidades atuais e a aumentar a sua disponibilidade e produtividade; e implementação de políticas de manutenção mais assertiva e focada no objetivo de “zero avarias”, como é o caso da manutenção preditiva. Neste contexto, o objetivo principal deste trabalho consiste na previsão do instante temporal ótimo da manutenção de um equipamento industrial – um refinador da fábrica de Mangualde da empresa Sonae Industria, que se encontra em funcionamento contínuo 24 horas por dia, 365 dias por ano. Para o efeito são utilizadas medidas de sensores que monitorizam continuamente o estado do refinador. A principal operação de manutenção deste equipamento é a substituição de dois discos metálicos do seu principal componente – o desfibrador. Consequentemente, o sensor do refinador analisado com maior detalhe é o sensor que mede a distância entre os dois discos do desfibrador. Os modelos ARIMA consistem numa abordagem estatística avançada para previsão de séries temporais. Baseados na descrição da autocorrelação dos dados, estes modelos descrevem uma série temporal como função dos seus valores passados. Neste trabalho, a metodologia ARIMA é utilizada para determinar um modelo que efetua uma previsão dos valores futuros do sensor que mede a distância entre os dois discos do desfibrador, determinando-se assim o momento ótimo da sua substituição e evitando paragens forçadas de produção por ocorrência de uma falha por desgaste dos discos. Os resultados obtidos neste trabalho constituem uma contribuição científica importante para a área da manutenção preditiva e deteção de falhas em equipamentos industriais.
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This paper presents the TEC4SEA research infrastructure created in Portugal to support research, development, and validation of marine technologies. It is a multidisciplinary open platform, capable of supporting research, development, and test of marine robotics, telecommunications, and sensing technologies for monitoring and operating in the ocean environment. Due to the installed research facilities and its privileged geographic location, it allows fast access to deep sea, and can support multidisciplinary research, enabling full validation and evaluation of technological solutions designed for the ocean environment. It is a vertically integrated infrastructure, in the sense that it possesses a set of skills and resources which range from pure conceptual research to field deployment missions, with strong industrial and logistic capacities in the middle tier of prototype production. TEC4SEA is open to the entire scientific and enterprise community, with a free access policy for researchers affiliated with the research units that ensure its maintenance and sustainability. The paper describes the infrastructure in detail, and discusses associated research programs, providing a strategic vision for deep sea research initiatives, within the context of both the Portuguese National Ocean Strategy and European Strategy frameworks.
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O setor da reabilitação em Portugal tem vindo a crescer consideravelmente ao longo dos últimos anos, demonstrando uma consciencialização da sociedade e das entidades competentes para definição de estratégias e planeamento, para uma manutenção das estruturas atempada de modo a prevenir patologias que provocam a sua degradação. O presente trabalho pretende fazer uma síntese das técnicas de proteção e reparação das estruturas de betão armado, efetuando também ensaios para determinação das causas das anomalias que levaram à sua reparação. O projeto de reabilitação deve seguir as recomendações indicadas nos Eurocódigos e norma EN1504 sobre produtos e sistemas para a proteção e reparação das estruturas de betão. Segundo esta norma explicam – se as principais causas de deterioração das estruturas de betão armado e os sintomas que estão na base dessa deterioração. Desta forma são descritos os métodos de intervenção, explicando o seu funcionamento e modo mais adequado de utilização com indicação dos produtos adequados para cada intervenção. Para aplicação do referido nos parágrafos anteriores desenvolveu-se uma proposta de fichas de inspeção, através de levantamento fotográfico e registo das anomalias e suas causas e ensaios não destrutivos de modo a perceber o estado atual da estrutura para uma melhor compreensão da metodologia de reparação a seguir
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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
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The analysis of molecular regulators involved in controlling the maintenance and function of plant meristems has been the subject of many studies. Some master regulators of these processes have been identified in Arabidopsis benefiting from the array of tools available for genetic and molecular analysis in this model plant. However, aspects such as secondary growth that are more extensively observed in woody plants, have been less studied. Secondary growth is responsible for the enlargement of the plant stems and roots and results from the activity of the lateral (secondary) meristems, vascular cambium and cork cambium (phellogen), which produce two important renewable natural resources, wood and cork, respectively.(...)
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The reduction of greenhouse gas emissions is one of the big global challenges for the next decades due to its severe impact on the atmosphere that leads to a change in the climate and other environmental factors. One of the main sources of greenhouse gas is energy consumption, therefore a number of initiatives and calls for awareness and sustainability in energy use are issued among different types of institutional and organizations. The European Council adopted in 2007 energy and climate change objectives for 20% improvement until 2020. All European countries are required to use energy with more efficiency. Several steps could be conducted for energy reduction: understanding the buildings behavior through time, revealing the factors that influence the consumption, applying the right measurement for reduction and sustainability, visualizing the hidden connection between our daily habits impacts on the natural world and promoting to more sustainable life. Researchers have suggested that feedback visualization can effectively encourage conservation with energy reduction rate of 18%. Furthermore, researchers have contributed to the identification process of a set of factors which are very likely to influence consumption. Such as occupancy level, occupants behavior, environmental conditions, building thermal envelope, climate zones, etc. Nowadays, the amount of energy consumption at the university campuses are huge and it needs great effort to meet the reduction requested by European Council as well as the cost reduction. Thus, the present study was performed on the university buildings as a use case to: a. Investigate the most dynamic influence factors on energy consumption in campus; b. Implement prediction model for electricity consumption using different techniques, such as the traditional regression way and the alternative machine learning techniques; and c. Assist energy management by providing a real time energy feedback and visualization in campus for more awareness and better decision making. This methodology is implemented to the use case of University Jaume I (UJI), located in Castellon, Spain.