997 resultados para cover-zone


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Dissertação de Mestrado, Gestão da Água e da Costa, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2009

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Dissertação de Mestrado, Gestão da Água e da Costa, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2010

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Dissertação de Mestrado, Oceanografia, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2007

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This special issue of Estuarine, Coastal and Shelf Science synthesizes and updates the developments in science related to Land Ocean Interactions in the Coastal Zone (LOICZ). Frequent updates about the dynamic coastal zone are useful and necessary as global change accelerates. There is an urgent need to improve the knowledge and understanding of the vulnerability of society and ecosystems to global change hazards in the coastal zone (Vermaat et al., 2005). The collection of papers in this special issue places new developments, findings, techniques and insights within the context of LOICZ science. For the convenience of the reader, the references to papers included in this special issue are printed in italic, whereas other references to LOICZ science are in normal print.

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Serpa and Moura region, in the South of Portugal, have important agricultural potential as well as important agricultural resources that can and should be used and developed, in spite of economic and social depression signs reinforced by demographic difficulties that can lead to desertification in some areas. The main farms' Technical-Economic Orientation (TEO) is olives production, to produce olive oil, since this region has excellent conditions for the activity development. Some mobilizations traditionally made in olive groves lead to soil erosion and make the farm vehicles mobility much more difficult, namely those used in cultural operations. The maintenance of a soil cover in the olive grove space between lines is good, both because it favours the vehicles mobility, it promotes the rain water infiltration and, last but not the least, the soil airing. The objective of this work has been to make a socio-economic characterization of a zone of Serpa and Moura Councils in which a project of soil covers under olive trees is being developed. At the same time cultural accounts were made for the different situations under the study - irrigated olive grove with spontaneous vegetation in the space between lines, irrigated olive grove with seeded vegetation in the space between lines, irrigated olive grove with herbicide application in the space between lines, dry olive grove with spontaneous vegetation in the space between lines, dry olive grove with seeded vegetation in the space between lines and dry olive grove with herbicide application in the space between lines. The survey shows farmers in this area are younger then usual, although they don't have a high level of formal education, general or specific in agriculture. Farm areas are usually high, which can be determinant for the proposed technology adoption. Installation and operation costs for the olive grove are higher on the irrigated olive grove, but of course expected productions are also higher. For this production technology profits coming from olives production are higher then the operation costs. However, in the dry olive grove technology costs are always higher then the profits, being profitability only due to subsidies. The importance of soil cover maintenance, in this region, beside the benefits in what concerns erosion, infiltration and soil airing, is also due to its capacity to minimize the risk farmer's face.

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Tese de mestrado, Neurociências, Faculdade de Medicina, Universidade de Lisboa, 2015

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This paper assesses whether two sustainability policies currently in effect in London, a congestion charge zone and a low emission zone, have affected freight operations and reduced vehicle kilometers travelled. It investigates responses by freight operators, including re-timing, re-routing, or reducing the number of trips, or replacing vehicles. Freight traffic trends from 1994 to 2012 were identified using road traffic estimates, cordon counts, and vehicle speed data and supplemented by interviews with freight industry experts and operators. Findings indicate that freight traffic increased throughout London during this timeframe, but declined in the central boroughs partly within the congestion charge zone. The congestion charge may have time-shifted some light goods trips, but most freight trips face a variety of constraints on operators’ delivery window. No evidence was found of re-routing of freight traffic or avoidance traffic around the charged zone. The low emission zone spurred higher levels of operational change than the congestion charge zone, and it was effective at spurring freight vehicle replacement. The paper also discusses freight operators’ perceptions of these policies and how they could be improved.

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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Vias de Comunicação e Transportes

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Adhesively-bonded joints are extensively used in several fields of engineering. Cohesive Zone Models (CZM) have been used for the strength prediction of adhesive joints, as an add-in to Finite Element (FE) analyses that allows simulation of damage growth, by consideration of energetic principles. A useful feature of CZM is that different shapes can be developed for the cohesive laws, depending on the nature of the material or interface to be simulated, allowing an accurate strength prediction. This work studies the influence of the CZM shape (triangular, exponential or trapezoidal) used to model a thin adhesive layer in single-lap adhesive joints, for an estimation of its influence on the strength prediction under different material conditions. By performing this study, guidelines are provided on the possibility to use a CZM shape that may not be the most suited for a particular adhesive, but that may be more straightforward to use/implement and have less convergence problems (e.g. triangular shaped CZM), thus attaining the solution faster. The overall results showed that joints bonded with ductile adhesives are highly influenced by the CZM shape, and that the trapezoidal shape fits best the experimental data. Moreover, the smaller is the overlap length (LO), the greater is the influence of the CZM shape. On the other hand, the influence of the CZM shape can be neglected when using brittle adhesives, without compromising too much the accuracy of the strength predictions.

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Fundação para a Ciência e a Tecnologia - SFRH/BD/42848/2008, através do Programa MIT_Portugal em Sistemas de Bioengenharia; projectos PTDC/SAUNEU/104415/2008 e Projecto ref. 96542 da Fundação Caloust Gulbenkian

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The rapid growth of big cities has been noticed since 1950s when the majority of world population turned to live in urban areas rather than villages, seeking better job opportunities and higher quality of services and lifestyle circumstances. This demographic transition from rural to urban is expected to have a continuous increase. Governments, especially in less developed countries, are going to face more challenges in different sectors, raising the essence of understanding the spatial pattern of the growth for an effective urban planning. The study aimed to detect, analyse and model the urban growth in Greater Cairo Region (GCR) as one of the fast growing mega cities in the world using remote sensing data. Knowing the current and estimated urbanization situation in GCR will help decision makers in Egypt to adjust their plans and develop new ones. These plans should focus on resources reallocation to overcome the problems arising in the future and to achieve a sustainable development of urban areas, especially after the high percentage of illegal settlements which took place in the last decades. The study focused on a period of 30 years; from 1984 to 2014, and the major transitions to urban were modelled to predict the future scenarios in 2025. Three satellite images of different time stamps (1984, 2003 and 2014) were classified using Support Vector Machines (SVM) classifier, then the land cover changes were detected by applying a high level mapping technique. Later the results were analyzed for higher accurate estimations of the urban growth in the future in 2025 using Land Change Modeler (LCM) embedded in IDRISI software. Moreover, the spatial and temporal urban growth patterns were analyzed using statistical metrics developed in FRAGSTATS software. The study resulted in an overall classification accuracy of 96%, 97.3% and 96.3% for 1984, 2003 and 2014’s map, respectively. Between 1984 and 2003, 19 179 hectares of vegetation and 21 417 hectares of desert changed to urban, while from 2003 to 2014, the transitions to urban from both land cover classes were found to be 16 486 and 31 045 hectares, respectively. The model results indicated that 14% of the vegetation and 4% of the desert in 2014 will turn into urban in 2025, representing 16 512 and 24 687 hectares, respectively.