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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Crônica de uma integração imperfeita. O caso da privatização dos portos e caminhos de ferro em Moçambique (2000-2005) / Crônica de uma Integração Imperfeita O caso da privatização da gestão dos Portos e Caminhos de Ferro em Moçambique (2000-2005)

Saúte, Nelson João Pedro 14 May 2010 (has links)
Constitui o escopo deste trabalho o estudo da privatização, em regime de concessão, dos Portos e Caminhos de Ferro de Moçambique (CFM), no quadro do ajustamento da economia moçambicana, recorrentemente dependente, imposto pelo Banco Mundial e pelo FMI, como forma de a integrar no mundo globalizado dominado pelo neo-liberalismo, no período pós-guerra civil. O caso do CFM permite-nos iluminar uma realidade mais ampla e complexa, que é a dinâmica histórica, económica e social de Moçambique, realidade marcada por fortes tensões sociais num contexto de permanente e inquietante mudança. / The scope of the present work comprises the study on privatization under the concessioning regime of the Ports and Railways of Mozambique within the context of economic structural adjustment recurrently dependent, imposed by the World Bank and IMF as a way to integrate it in a globalized world dominated by neo-liberal policies. The CFM case study allows us to scrutinize a wide and complex reality that is the historic, economic and social changes, a reality highlighted by social tensions in the context of permanent and changes.
42

Análise do comportamento de via permanente lastrada com emprego de sublastro betuminoso. / Analysis of the engineering behaviour of railway containing a bituminous subballast.

Alves, Talita de Freitas 27 February 2018 (has links)
Ao longo de sua vida útil, com o acúmulo de tráfego e de solicitações ambientais, infraestruturas de transportes degradam-se em termos de desgaste dos seus componentes e deformações permanentes de suas camadas, acarretando na perda gradual da qualidade estrutural e funcional da via. A camada de sublastro, parte integrante da subestrutura ferroviária, possui contribuição significativa no comportamento mecânico global de uma via permanente. Suas principais funções estão relacionadas à drenagem, atenuação e distribuição de tensões, e separação e transição entre as camadas de lastro e subleito. O objetivo principal deste estudo foi comparar duas diferentes configurações de sublastro implementadas em uma ferrovia de carga brasileira através da medição de respostas mecânicas e parâmetros geométricos \"in situ\". O emprego de sublastro betuminoso constituiu-se como a primeira aplicação de campo deste tipo no País e ambas as seções foram monitoradas também por intermédio de sensores de temperatura e de tensão. Procedeu-se a caracterização física e mecânica dos materiais que compõem os trechos analisados em laboratório. Ademais, tensões de sucção foram medidas em diferentes locais e profundidades da camada de subleito, a fim de verificar a eficácia da camada betuminosa em impermeabilizar as camadas subjacentes. Os resultados mostraram uma eficiência global superior do trecho contendo sublastro betuminoso comparativamente à seção de referência (sublastro granular). Variações das tensões de sucção ao longo de duas estações climáticas mostraram que a mistura asfáltica protegeu satisfatoriamente o subleito quanto à infiltração de água oriunda das precipitações. Medidas de temperatura tomadas em diferentes pontos das camadas de sublastro mostraram que a mistura asfáltica se encontra protegida das variações térmicas e da incidência de radiação solar, uma vez que está isolada pela camada de lastro. Em termos de deslocamentos medidos com o equipamento DMD (Dispositivo para Medição de Deslocamentos), mostrou-se uma redução crescente no deslocamento vertical médio da seção com sublastro betuminoso em comparação com a seção com sublastro granular. Por consequência, o módulo de via, u, calculado para ambas as seções, revelou que o perfil contendo mistura asfáltica tende a defletir menos quando solicitado pela passagem de trens. Medidas de parâmetros geométricos utilizando o equipamento Trolley AMBER apontaram uma relação bidirecional entre o comportamento mecânico e a qualidade da geometria da via, observada antes e após intervenção mecanizada de socaria. / In the course of its service life, with traffic loading accumulation in addition to environmental effects, transportation infrastructures tend to degrade in terms of wear of their components and permanent deformation of their layers, resulting in the gradual loss of structural and functional quality of the railway. The subballast plays an important role as part of the railway substructure and it has a significant contribution to the overall mechanical behavior of the track. Its main functions are related to drainage, to load attenuation and distribution, and to the separation and transition between the ballast and the subgrade. The main objective of this study was to compare two different subballast configurations implemented in a freight railway profile in Brazil through measurements of mechanical and geometric parameters in field. The use of bituminous subballast was the first application of this type in the country and both sections were also monitored by means of temperature and pressure sensors. Laboratory tests for physical and mechanical characterization for all materials composing both experimental sections were performed. In addition, the water pressure in terms of suction were measured at different places and depths of the subgrade, in order to verify the effectiveness of the bituminous subballast in waterproofing the underlying layers. The results showed a superior overall efficiency of the section containing bituminous subballast compared to the reference section (granular subballast). The suction tension variation measured along two climatic seasons showed that the asphalt mixture satisfactorily protects the subgrade from the infiltration of water due precipitations. Temperature measurements taken at different points of the subballast layers showed that the asphalt mixture is protected from thermal and solar radiation peaks, since it is isolated by the ballast layer from atmospheric environmental effects. In terms of displacements acquired using the DMD (Displacement Measurement Device) it was observed an increasing reduction in the mean vertical displacement of the section with bituminous subballast compared to the section with granular subballast. Consequently, the track modulus, u, calculated for both sections revealed that the profile containing asphalt mixture tends to deflect less when requested by the train passage. Measurements of geometric parameters made with the Trolley AMBER device highlighted the bidirectional relationship between the mechanical behavior and the quality of the track geometry, observed before and after tamping procedure.
43

"Os trilhos nas áreas urbanas: conflitos, desafios e oportunidades em dez cidades paulistas" / Railways in urbanized areas: challenging conflicts and opportunities for ten cities in São Paulo state.

Luz, Luciano Ferreira da 24 July 2006 (has links)
O destaque alcançado por um grupo significativo de cidades do interior do estado de São Paulo, que nas últimas décadas só foi mais reforçado pelo dinamismo econômico, evidenciou os aspectos que as projetam como pólos regionais. Nesse grupo de cidades ressalta-se a extrema urbanização, em muitas delas uma avançada conurbação com as vizinhas. Surgem aglomerações, que vão de 500 mil a mais de dois milhões de habitantes, formando uma rede de cidades que lideram o segundo maior mercado consumidor brasileiro. A atividade industrial crescente, a geração de empregos, o conseqüente crescimento demográfico e o espraiamento urbano, deram a essas cidades características de organização espacial muito própria e um sistema viário que não acompanhou esse crescimento, mais expressivo do que os das grandes capitais. Contudo, um elemento está presente em todas essas cidades e constitui um rico patrimônio histórico e, talvez, estratégico em seus futuros: a ferrovia. Nas dez maiores cidades do interior paulista, a presença marcante da velha estação e da linha férrea, que as cruzam e as dividem, são as heranças do processo de desmantelamento e total abandono da função ferroviária de transporte de passageiros de longo percurso. Quase sempre relegadas a funções acessórias no planejamento urbano, a ferrovia também esteve distante, encerrada entre seus muros, mantendo o diálogo com as cidades embaraçado ao longo do tempo. Essa pesquisa se propôs a fazer um levantamento geral desses patrimônios ferroviários, identificar suas interfaces atuais com o meio urbano, os novos agentes envolvidos na sua exploração e, principalmente, a visão e os usos pretendidos pelos municípios para as faixas ferroviárias e suas áreas lindeiras. Buscando amparo nas evoluções históricas, na análise de influências recíprocas e nas relações entre transporte e urbanismo, questiona-se a presença dos trilhos nessas áreas intensamente urbanizadas e são expostas as relações institucionais que devem ser consideradas para planejar e viabilizar o seu aproveitamento, seja pela implantação de novos equipamentos urbanos, pelo uso compartilhado de transportes ou mesmo pela sua erradicação. / A large number of relevant cities in the countryside of São Paulo state has recently faced a remarkable distinction brought by a high economical dinamism in these regional poles during the last decades. These cities already have extreme urbanization rates and they are getting aglomerated, creating new metropolitan areas, with a huge population that is responsible for Brazil´s second largest consuming market. The increasing industrial activity and the offers of new jobs have both stimulated the spreading of its urbanized areas that are not always followed by enough new transportation infra structures. However, one element is very present in any of these cities and it stands for rich historical assets: the old railway. Inside any medium size São Paulo´s city in, the prominent station and the rail tracks still divide the urban center, instersecting its streets and being source of many conflicts and accidents. Nowadays, those abandoned structures are the inheritahe of passenger rail transportation, which was completely dismantled after freight rail transports privatizations. Specially inside the cities, not only the railways were continualy limited to secondary functions in all urban planning process, but the urban transportation was never taken as a priority for rail administration either. This research aimed to build a general view of railway equipments and structures of ten cities, identify possible interfaces with their urban areas, identify the agents envolved in its exploitation and mainly identify what the local expectations to the railways are. The analysis was done based on historical evolution of railways and cities, by the influence of transportation infra structure on territories. Urbanism and public transport organization notions were considered as well, in order to identify the needs and ways on what kind of railway would contribute or would be more profitable in new urban functions.
44

Crônica de uma integração imperfeita. O caso da privatização dos portos e caminhos de ferro em Moçambique (2000-2005) / Crônica de uma Integração Imperfeita O caso da privatização da gestão dos Portos e Caminhos de Ferro em Moçambique (2000-2005)

Nelson João Pedro Saúte 14 May 2010 (has links)
Constitui o escopo deste trabalho o estudo da privatização, em regime de concessão, dos Portos e Caminhos de Ferro de Moçambique (CFM), no quadro do ajustamento da economia moçambicana, recorrentemente dependente, imposto pelo Banco Mundial e pelo FMI, como forma de a integrar no mundo globalizado dominado pelo neo-liberalismo, no período pós-guerra civil. O caso do CFM permite-nos iluminar uma realidade mais ampla e complexa, que é a dinâmica histórica, económica e social de Moçambique, realidade marcada por fortes tensões sociais num contexto de permanente e inquietante mudança. / The scope of the present work comprises the study on privatization under the concessioning regime of the Ports and Railways of Mozambique within the context of economic structural adjustment recurrently dependent, imposed by the World Bank and IMF as a way to integrate it in a globalized world dominated by neo-liberal policies. The CFM case study allows us to scrutinize a wide and complex reality that is the historic, economic and social changes, a reality highlighted by social tensions in the context of permanent and changes.
45

On-line control of a simplified simulated route of the Hong Kong Mass Transit Railway.

Yip, Kar-mao. January 1976 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1977. / Photocopy of typecript.
46

Road Ecology for Environmental Assessment

Karlson, Mårten January 2015 (has links)
Transport infrastructure is closely linked to several politically relevant sustainability issues, and since 1985 a formalized environmental assessment process is linked to planning and construction of new roads and railways in the EU (EU directives 85/337/EEC and 2001/42). The aim of the environmental assessment process is to think in advance; to identify, predict and evaluate significant environmental changes resulting from a proposed activity, in order to adjust the proposed activity accordingly and to avoid unnecessary and unexpected consequences. Biodiversity is a component of sustainable development that is in many ways affected by road and railway construction, but which has been challenging to fully account for within the environmental assessment process. This thesis presents four studies on the role of biodiversity in environmental assessment of road and railway plans and projects. Paper I presents the state of the art of road and railway impacts on ecological patterns and processes sustaining biodiversity, and reviews the treatment of biodiversity in a selection of environmental assessment reports from Sweden and the UK. Paper II presents a quantitative assessment of the impact of the Swedish road network on birds and mammals, and how fragmentation and road disturbance might affect a selection of ecological profiles. Paper III demonstrates how scientific models, data and knowledge can be mobilized for the design and evaluation of railway corridors, and Paper IV analyses how habitat connectivity, as a prerequisite of genetic exchange, relates to landscape composition and size and number of fauna passages. The results from Paper I show that road and railway impacts on biodiversity need to be addressed at every level of planning; from corridor alignment in the landscape to utilization and maintenance. The review of environmental assessment reports shows that the treatment of biodiversity in environmental assessment has improved over the years, but that problems with habitat fragmentation, connectivity and the spatial delimitation of the impact assessment study area remain. The results from Paper II identify natural grasslands and southern broadleaved forest, prioritized habitat types important for biodiversity, to most likely be highly affected by road impacts, and suggest road disturbance to have a high impact on overall habitat availability. The results from Paper III demonstrate how the landscape specific distribution of ecological and geological resources can be accounted for in railway corridor design, and potentially lead to more resource efficient outcomes with less impact on ecological processes. The results from Paper IV indicate that the several small fauna passages would increase connectivity more across a barrier than the construction of a single large. Effective barrier mitigation will also depend on the selection of focal species and the understanding of how the focal species perceive the landscape in terms of resistance to movement. This thesis demonstrates how quantitative assessment can benefit biodiversity impact analysis and address issues such as habitat connectivity and fragmentation, which have been difficult to account for in environmental assessment. It is recommended that biodiversity impact analysis moves towards an increasing use of quantitative methods and tools for prediction, evaluation and sensitivity analysis. Future challenges include verification and calibration of relevant spatial ecological models, and further integration of road ecology knowledge into road and railway planning. / <p>QC 20151103</p> / GESP
47

Development of a limit state design methodology for railway track

Leong, Jeffrey January 2007 (has links)
The research presented in this thesis is aimed at developing a limit state design methodology for railway track for recommendation to Standards Australia's next revision of the 'Permanent way materials: prestressed concrete sleepers' code (AS1085.14, 2003). There is widespread suspicion that the railway track, particularly concrete sleepers, have untapped reserves of strength that has potential engineering and economic advantages for track owners. Through quantifying the effects of train speed, wheel impact loadings and distribution of vehicle loads, track engineers would be able to design railway track more accurately and hence uncover the reserves of strengths in railway track. To achieve this improvement a comprehensive set of wheel/rail impact measurements has been collected over a one year period to establish a distribution of track loadings. The wheel/rail impact data collected showed a logarithmically linear distribution which shows that impact forces are randomly occurring events. The linearity of the data also allows for wheel/rail impact forces to be forecasted allowing for a more rational risk based design of the railway track. To help with an investigation of the influence of changes to train operation on the wheel/rail impact force distributions, development of a new dynamic track computer model capable of simulating the complex interaction between the train and track was completed within this research. The model known as DTRACK (Dynamic analysis of rail TRACK) was benchmarked against other dynamic models and field data to validate its outputs. The field measurements and DTRACK simulations became the basis for development of a limit state design methodology for railway track (risk based approach) for railway track in place of an allowable limit state (compliance based) approach. This new approach will allow track owners to assess the track capacity based on more realistic loads and is expected to allow an increase in the capacity of existing track infrastructure which will allow railways to be more commercially competitive and viable.
48

Metoder för vegetationsbekämpning på banvallar : en summering av resultat från UICs Vegetation Control Project och erfarenheter från Institutionen för landskaps- och trädgårdsteknik = Vegetation control methods on railway embarkment and track area/

Eriksson, Anna-Mia. Hansson, David. Huisman, Mark. Lundh, Jan-Erik. January 2004 (has links) (PDF)
Examensarbete. / Delrapport i FoU-projekt S 01-3284/08 "Skötsel av vegetation inom banområde"
49

The microbiology of railway tracks : towards a rational use of herbicides on Swedish railways /

Cederlund, Harald, January 2006 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.
50

Cost function regularity and economies of scale, scope, and total factor productivity: an application to class I Canadian railways, 1956-81.

Lall, Ashish, Carleton University. Dissertation. Economics. January 1992 (has links)
Thesis (Ph. D.)--Carleton University, 1992. / Also available in electronic format on the Internet.

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