10 resultados para Riparian areas -- Soria (Spain)
em Instituto Politécnico do Porto, Portugal
Resumo:
Electric vehicles introduction will affect cities environment and urban mobility policies. Network system operators will have to consider the electric vehicles in planning and operation activities due to electric vehicles’ dependency on the electricity grid. The present paper presents test cases using an Electric Vehicle Scenario Simulator (EVeSSi) being developed by the authors. The test cases include two scenarios considering a 33 bus network with up to 2000 electric vehicles in the urban area. The scenarios consider a penetration of 10% of electric vehicles (200 of 2000), 30% (600) and 100% (2000). The first scenario will evaluate network impacts and the second scenario will evaluate CO2 emissions and fuel consumption.
Resumo:
During the past 15 years, emergence and dissemination of third-generation cephalosporins resistance in nosocomial Enterobacteriaceae became a serious problem worldwide, due to the production of extended-spectrum-β-lactamases (ESBLs). The aim of this study was to investigate among the presence of ESBL-producing enterobacteria among Portuguese clinical isolates nearby Spain, to investigate the antimicrobial susceptibility patterns and to compare the two countries. The β-lactamases genes, blaTEM, blaSHV and blaCTX-M were detected by molecular methods. Among the ESBL-producing isolates it was found extraordinary levels (98.9%) of resistance to the fourth-generation cephalosporin Cefepime. These findings point to the need of reevaluate the definition of ESBL.
Resumo:
Pesticide exposure during brain development could represent an important risk factor for the onset of neurodegenerative diseases. Previous studies investigated the effect of permethrin (PERM) administered at 34 mg/kg, a dose close to the no observable adverse effect level (NOAEL) from post natal day (PND) 6 to PND 21 in rats. Despite the PERM dose did not elicited overt signs of toxicity (i.e. normal body weight gain curve), it was able to induce striatal neurodegeneration (dopamine and Nurr1 reduction, and lipid peroxidation increase). The present study was designed to characterize the cognitive deficits in the current animal model. When during late adulthood PERM treated rats were tested for spatial working memory performances in a T-maze-rewarded alternation task they took longer to choose for the correct arm in comparison to age matched controls. No differences between groups were found in anxiety-like state, locomotor activity, feeding behavior and spatial orientation task. Our findings showing a selective effect of PERM treatment on the T-maze task point to an involvement of frontal cortico-striatal circuitry rather than to a role for the hippocampus. The predominant disturbances concern the dopamine (DA) depletion in the striatum and, the serotonin (5-HT) and noradrenaline (NE) unbalance together with a hypometabolic state in the medial prefrontal cortex area. In the hippocampus, an increase of NE and a decrease of DA were observed in PERM treated rats as compared to controls. The concentration of the most representative marker for pyrethroid exposure (3-phenoxybenzoic acid) measured in the urine of rodents 12 h after the last treatment was 41.50 µ/L and it was completely eliminated after 96 h.
Resumo:
The aim of this work was to assess the influence of meteorological conditions on the dispersion of particulate matter from an industrial zone into urban and suburban areas. The particulate matter concentration was related to the most important meteorological variables such as wind direction, velocity and frequency. A coal-fired power plant was considered to be the main emission source with two stacks of 225 m height. A middle point between the two stacks was taken as the centre of two concentric circles with 6 and 20 km radius delimiting the sampling area. About 40 sampling collectors were placed within this area. Meteorological data was obtained from a portable meteorological station placed at approximately 1.7 km to SE from the stacks. Additional data was obtained from the electrical company that runs the coal power plant. These data covers the years from 2006 to the present. A detailed statistical analysis was performed to identify the most frequent meteorological conditions concerning mainly wind speed and direction. This analysis revealed that the most frequent wind blows from Northwest and North and the strongest winds blow from Northwest. Particulate matter deposition was obtained in two sampling campaigns carried out in summer and in spring. For the first campaign the monthly average flux deposition was 1.90 g/m2 and for the second campaign this value was 0.79 g/m2. Wind dispersion occurred predominantly from North to South, away from the nearest residential area, located at about 6 km to Northwest from the stacks. Nevertheless, the higher deposition fluxes occurred in the NW/N and NE/E quadrants. This study was conducted considering only the contribution of particulate matter from coal combustion, however, others sources may be present as well, such as road traffic. Additional chemical analyses and microanalysis are needed to identify the source linkage to flux deposition levels.
Resumo:
Despite the abundant literature in knowledge management, few empirical studies have explored knowledge management in connection with international assignees. This phenomenon has a special relevance in the Portuguese context, since (a) there are no empirical studies concerning this issue that involves international Portuguese companies; (b) the national business reality is incipient as far as internationalisation is concerned, and; (c) the organisational and national culture presents characteristics that are distinctive from the most highly studied contexts (e.g., Asia, USA, Scandinavian countries, Spain, France, The Netherlands, Germany, England and Russia). We examine the role of expatriates in transfer and knowledge sharing within the Portuguese companies with operations abroad. We focus specifically on expatriates’ role on knowledge sharing connected to international Portuguese companies and our findings take into account organizational representatives’ and expatriates’ perspectives. Using a comparative case study approach, we examine how three main dimensions influence the role of expatriates in knowledge sharing among headquarters and their subsidiaries (types of international assignment, reasons for using expatriation and international assignment characteristics). Data were collected using semi‐structured interviews to 30 Portuguese repatriates and 14 organizational representatives from seven Portuguese companies. The findings suggest that the reasons that lead Portuguese companies to expatriating employees are connected to: (1) business expansion needs; (2) control of international operations and; (3) transfer and knowledge sharing. Our study also shows that Portuguese companies use international assignments in order to positively respond to the increasingly decaying domestic market in the economic areas in which they operate. Evidence also reveals that expatriation is seen as a strategy to fulfill main organizational objectives through their expatriates (e.g., business internationalization, improvement of the coordination and control level of the units/subsidiaries abroad, replication of aspects of the home base, development and incorporation of new organizational techniques and processes). We also conclude that Portuguese companies have developed an International Human Resources Management strategy, based on an ethnocentric approach, typically associated with companies in early stages of internationalization, i.e., the authority and decision making are centered in the home base. Expatriates have a central role in transmitting culture and technical knowledge from company’s headquarters to the company’s branches. Based on the findings, the article will discuss in detail the main theoretical and managerial implications. Suggestions for further research will also be presented.
Resumo:
Los procesos de acogimiento familiar que se producen en cada país dependen de factores históricos y culturales que dan lugar a grandes diferencias internacionales. A pesar de que las comparativas internacionales ofrecen un medio de intercambio de experiencias, lo que permite el aprendizaje mutuo y la transferencia de buenas prácticas, a menudo encontramos enormes barreras para su realización debido, entre otros factores, al limitado acceso a los datos sobre la práctica de la protección infantil. Frente a estas limitaciones, este artículo ofrece una investigación comparativa realizada en España y Portugal, cuyo objetivo ha sido la evaluación del acogimiento familiar en dos países donde la investigación en el ámbito de la protección infantil há sido tradicionalmente desatendida. Sobre una muestra de 357 casos en España y 289 en Portugal, se realizó un estudio del perfil de características de los niños acogidos, las familias de origen y los acogedores, así como de los procesos de acogida en ambos países. La comparativa reveló importantes diferencias relacionadas con la mayor edad al inicio del acogimiento de los niños en España; el perfil de los acogedores, con edades más avanzadas, un bajo nivel educativo y llevando a cabo acogidas de más de un niño simultaneamente en Portugal. El estudio comparado nos ha permitido identificar áreas que requieren mayor atención en ambos países, como la renovación generacional del banco de acogedores en Portugal o la necesidad de acelerar los procesos de toma de decisiones para la entrada en acogimiento familiar en España. Se pretende que este artículo sirva de aliento para la recogida de datos y comparación con otros países iberoamericanos.
Resumo:
TICAI 2008 é o terceiro volume de uma série que recolhe as contribuições mais significativas dos melhores congressos de língua espanhola e Portuguesa no âmbito da Sociedade de Educação do IEEE. Este volume corresponde aos eventos realizados no ano de 2008, é promovido pelos Capítulos Português e Espanhol desta Sociedade. Como os volumes anteriores, o âmbito centra-se na investigação e aplicações da tecnologia na educação e engloba o desenho e investigação de novas ferramentas, materiais e técnicas que facilitem o ensino/ aprendizagem e aplicações, métodos pedagógicos e experiências concretas de uso destas novas técnicas e ferramentas. Tudo com um enfoque particular no ensino/ aprendizagem das disciplinas próprias do IEEE, fundamentalmente nas áreas da Engenharia Electrotécnica, Tecnologia Electrónica, Engenharia de Telecomunicações e Engenharia Informática. Assim, os capítulos deste livro passaram pelo crivo apertado de duas revisões: primeiro do próprio congresso e depois uma segunda selecção de entre os artigos aceites para o congresso. Para esse processo, contamos com membros destacados de cada um dos Comités de Organização ou de programa dos respectivos congressos.
Resumo:
Every year forest fires consume large areas, being a major concern in many countries like Australia, United States and Mediterranean Basin European Countries (e.g., Portugal, Spain, Italy and Greece). Understanding patterns of such events, in terms of size and spatiotemporal distributions, may help to take measures beforehand in view of possible hazards and decide strategies of fire prevention, detection and suppression. Traditional statistical tools have been used to study forest fires. Nevertheless, those tools might not be able to capture the main features of fires complex dynamics and to model fire behaviour [1]. Forest fires size-frequency distributions unveil long range correlations and long memory characteristics, which are typical of fractional order systems [2]. Those complex correlations are characterized by self-similarity and absence of characteristic length-scale, meaning that forest fires exhibit power-law (PL) behaviour. Forest fires have also been proved to exhibit time-clustering phenomena, with timescales of the order of few days [3]. In this paper, we study forest fires in the perspective of dynamical systems and fractional calculus (FC). Public domain forest fires catalogues, containing data of events occurred in Portugal, in the period 1980 up to 2011, are considered. The data is analysed in an annual basis, modelling the occurrences as sequences of Dirac impulses. The frequency spectra of such signals are determined using Fourier transforms, and approximated through PL trendlines. The PL parameters are then used to unveil the fractional-order dynamics characteristics of the data. To complement the analysis, correlation indices are used to compare and find possible relationships among the data. It is shown that the used approach can be useful to expose hidden patterns not captured by traditional tools.
Resumo:
A presente dissertação teve como objetivo fazer uma análise da viabilidade técnica da utilização dos condutores de alta temperatura nas linhas aéreas de MT, identificar vantagens, analisar inconvenientes, e estabelecer um comparativo a custos médios com as soluções convencionais. Foi efetuado o estudo de um caso real da EDP Distribuição que consistia na necessidade do aumento da capacidade de transporte de energia da linha aérea a 15 kV Espinho-Sanguedo. Neste foi ponderada a solução onde se poderia efetuar passagem de linha simples para linha dupla em alumínio-aço (AA) 160 mm2 ou a solução alternativa e inovadora de substituição dos condutores existentes por condutores de alta temperatura ACCC 182 mm2. Para isso foram efetuados cálculos e também criada uma ferramenta de apoio à decisão, para validação dos mesmos, com o intuito de mais tarde poder ser aplicada nas linhas aéreas em Média Tensão em todo o país e, sempre que necessário, se possa fazer um estudo de ponderação técnica de forma sistemática e estruturada. Neste trabalho estão identificadas as vantagens, foram relatados os inconvenientes, e estabeleceu-se um comparativo a custos médios da utilização de condutores de alta temperatura com as soluções convencionais. Antes de poder ser realizado um estudo do caso concreto da Linha aérea Espinho-Sanguedo foi necessário um aprofundamento do estado da arte no que diz respeito à comparação entre o cabo de alta temperatura ACCC e o cabo convencional ACSR, sendo este o mais utilizado nas linhas aéreas em MT. Os cabos de alta temperatura trouxeram inovações neste tema de transporte de energia, e como tal surgiu a necessidade de um estudo mais aprofundado da sua constituição, destacando o seu núcleo formado pelo compósito de fibra de carbono e fibra de vidro. Foi também analisado vantagens e desvantagens do cabo de alta temperatura e até mesmo situações onde a sua aplicação poderá ser vantajosa, de modo a tirar proveito das suas caraterísticas em que se destacam altas temperaturas de funcionamento e flechas reduzidas. Para elaborar um projeto de uma linha aérea em média tensão é necessário considerar a legislação em vigor, os aspetos ambientais e económicos, respeitando e garantindo as premissas do cálculo elétrico e mecânico. Economicamente este tipo de cabo (ACCC) é mais dispendioso do que os convencionais, no entanto o estudo realizado permitiu perceber que a sua implementação técnica é vantajosa em linhas aéreas de elevada capacidade de transporte de energia, sobretudo nos casos onde serão necessárias instalar linhas duplas ou linhas simples de seções elevadas. Devido às suas caraterísticas mecânicas, estes cabos permitem melhorar as linhas na sua dimensão, podendo diminuir o número de apoios a instalar, podendo diminuir a robustez dos apoios e permitir maior facilidade na montagem. Estas vantagens traduzem-se em menores impactos ambientais e permitem sobretudo reduzir os constrangimentos com os proprietários dos terrenos onde os apoios são implantados.
Resumo:
The aim of this study was to undertake a comparative analysis of the practices and information behaviour of European information users who visit information units specialising in European information in Portugal and Spain. The study used a quantitative methodology based on a questionnaire containing closed questions and one open question. The questions covered the general sociological profile of the respondents and their use of European Document Centres, in addition to analysing aspects associated with information behaviour relating to European themes. The study therefore examined data on the preferred means and sources for accessing European information, types of documents and the subjects investigated most. The use of European databases and the Internet to access material on Europe was also studied, together with the reasons which users considered made it easy or difficult to access European information, and the aspects they valued most in accessing this information. The questionnaire was administered in European Document Centres in 2008 and 2010.