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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

Impactos na produção de energia nas usinas hidroelétricas do rio Tietê em decorrência do transporte hodroviário / Impacts on energy production in hydroelectric plants of the Tiete river as a result of water transport

Lopes, Wagner Pernias 17 August 2018 (has links)
Orientador: Alberto Luiz Francato / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-17T19:07:21Z (GMT). No. of bitstreams: 1 Lopes_WagnerPernias_M.pdf: 6621269 bytes, checksum: 0b0897224320a8583df095412b26f107 (MD5) Previous issue date: 2011 / Resumo: A dissertação propõe a utilização de metodologias de otimização e simulação para avaliação de impactos energéticos para uma cascata de aproveitamento múltiplo (navegação e geração hidrelétrica), considerando-se diversos cenários de crescimento setoriais e incertezas hidrológicas. A eficiência dos segmentos de transporte e energia é fundamental para o desempenho competitivo em um ambiente de economia globalizada. Países em desenvolvimento de dimensões continentais como a República Popular da China, Índia e Federação Russa têm apresentado elevadas taxas de crescimento econômico, subsidiadas por intensos investimentos nos setores de transporte e energia. O Brasil utiliza pouco o seu potencial natural para a navegação de interior. As poucas instalações existentes, com o propósito de uso múltiplo estão subutilizadas para navegação. Neste cenário, o Brasil, através de políticas setoriais de investimentos tem fomentado o desenvolvimento dos setores de infra-estrutura, principalmente o de transporte e energia. Neste contexto, a dissertação apresenta os resultados obtidos com aplicação da metodologia de otimização e simulação em um estudo de caso para a cascata do rio Tietê. A metodologia para avaliação de impactos proposta nesta dissertação apresenta grande relevância para os setores de energia e transportes, além de trazer contribuição científica para análise integrada de problemas em modelos de simulação e otimização / Abstract: The paper proposed the use of optimization and simulation methodologies for assessing impacts on energy production in a cascade of multiple use (navigation and hydropower generation) for various scenarios of sectoral growth and hydrological uncertainties. The efficiency of transport and energy sectors is important to the competitive performance of a country in an environment of a global economy. Developing countries with large continental dimensions, such as Popular Republic of China, India and Russia, have presented high rates of economic growth, which is subsidized by heavy investments in transport and energy. Brazil makes little use of its great natural potential for inland navigation. The few facilities established with the purpose of multiple use are underutilized for navigation. In this scenario, Brazil, through local policies and investment programs, has encouraged the development of the sectors of infrastructure, particularly for transportation and energy. In this context, this dissertation presents the methodology and the results obtained from a case study of a stretch of the Tietê river. The methodology for impact assessment proposed in this thesis is highly relevant to the sectors of energy and transport, besides bringing scientific contribution to the integrated analysis of problems related to simulation models and optimization / Mestrado / Recursos Hidricos, Energeticos e Ambientais / Mestre em Engenharia Civil
42

Cidade-Canal de Ibiúna e Hidrovia do Alto Sorocaba: interligação hidroanel metropolitano-hidrovia Tietê - Paraná / City-Channel of Ibiúna and waterway of the Alto Sorocaba: metropolitan hydroelectric interconnection - Tietê-Paraná waterway

André Villas Boas 18 May 2017 (has links)
O presente trabalho se enquadra na visão de projeto como pesquisa e desenvolve a arquitetura do programa de uma cidade fluvial a ser implantada no leito maior do ribeirão da Vargem Grande e do Sorocamirim, rios que fazem a divisa entre os municípios de Ibiúna, São Roque e Vargem Grande Paulista e estão situados na subbacia hidrográfica do Alto Sorocaba, gerenciada pelo Comitê de Bacia Hidrográfica do rio Sorocaba e Médio Tietê. A partir da tríade programa, lugar e construção, é feito um ensaio projetual que serve à abordagem de conceitos como urbanismo lento e rua viva. A Cidade-Canal de Ibiúna é uma cidade linear de 25km construída ao longo de um sistema de lagos-canais que, em grande parte do percurso, preserva o curso do leito menor do rio Sorocamirim e do ribeirão da Vargem Grande. A Cidade-Canal faz contraponto à cidade rodoviarista e propõe uma nova temporalidade ao estruturar-se em torno da presença material da água na vida cotidiana de seus habitantes e do espaço da várzea como paisagem urbana. Um sistema de parques fluviais é criado com o objetivo de recuperar a mata ciliar nativa e garantir a oferta hídrica para funcionamento das infraestruturas hidráulicas dentro da lógica do uso múltiplo das águas. O canal artificial de navegação é uma hidrovia urbana. Potencialmente, a Hidrovia do Alto Sorocaba, como parte da Hidrovia do Alto-Médio Tietê, poderia fazer a interligação entre a rede hidroviária do Alto Tietê (Hidroanel Metropolitano) e a Hidrovia Tietê-Paraná ao vencer um divisor de águas e um desnível líquido total de 183m entre os munícipios de Santana do Parnaíba e Salto. Porém, diante das dificuldades físico-territoriais e operacionais de um sistema tão complexo, o potencial mais promissor da Hidrovia do Sorocaba é o de conectar, ao longo de seus cerca de 200km, uma série de outras estruturas urbanas de modo a conformar uma rede de cidades-fluviais modelo. Esta pesquisa se alinha aos interesses do Grupo Metrópole Fluvial (GMF), pertencente ao Laboratório de Projeto do Departamento de Projeto (LabProj) da Faculdade de Arquitetura e Urbanismo da Universidade de São Paulo (FAU USP) e visa difundir a cultura de projeto de arquitetura de infraestruturas urbanas fluviais. / This work pertains to the vision of project as research and elaborates the architecture of the program of a fluvial city to be set up in the larger riverbed of Vargem Grande creek and Sorocamirim river, that divide the municipalities of Ibiúna, São Roque, and Vargem Grande Paulista and are situated in the Alto Sorocaba hydrographic subbasin, managed by the Hydrographic Basin Committee of the Sorocaba and Médio Tietê rivers. Based on the triad \"program, place, and construction\", a project essay is made to approach concepts such as slow urbanism and living street. Ibiúna Canal-City is a linear city of 25km built alongside a system of canal lakes that, in a long stretch of its trajectory, preserves the course of the smaller riverbeds of the Sorocamirim river and the Vargem Grande creek. The canal-city is a counterpoint to the motorway city and proposes a new temporality structured around the material presence of water in the daily life of the inhabitants and of the space of the marshes as an urban landscape. A system of fluvial parks is created with the goal of restoring the native ciliary woods and guaranteeing the hydric offer for the operation of the hydraulic infrastructures within the logic of the multiple usages of the waters. The artificial navigation canal is an urban waterway. The Alto Sorocaba Waterway, as part of the Alto-Médio Tietê Waterway, could potentially make the connection between the Alto Tietê waterway network (Metropolitan Waterway Ring) and the Tietê-Paraná Waterway, bridging a watershed and a total liquid elevation of 183m between the municipalities of Santana de Parnaíba and Salto. However, given the physical, territorial, and operational difficulties of such a complex system, the most promising potential of the Sorocaba Waterway is to connect, along its approximately 200km, a series of other urban structures so as to form a network of model fluvial cities. This research is aligned with the interests of the Fluvial Metropolis Group (GMF), that belongs to the Project Laboratory of the Project Department (LabProj) of the Architecture and Urbanism School of the University of São Paulo (FAU USP), and it aims at disseminating the culture of the architecture project of urban fluvial infrastructures.
43

Effects Of Seepage On Incipient Motion, Resistance, Stability And Mobility Of Sand Bed Channels

Sitaram, Nagaraj 08 1900 (has links) (PDF)
No description available.
44

Impacts of Deforestation on Water Quality and Quantity in a Canadian Agricultural Watershed

Noteboom, Matthew 10 September 2020 (has links)
Around the world, many forested areas have been and continue to be cleared for expanding agriculture. Canada’s remaining forested lands account for around 9% of the world’s forest cover. Although only a fraction is lost to deforestation annually (0.02%, 2013), Statistics Canada reports that conversion to agriculture is the most significant driver of forest loss. As climate changes and agricultural demand expands, this trend is expected to continue, and ecosystems will continue to be impacted by resulting habitat loss and hydrological changes that can impact infrastructure and communities. Additionally, changes to sediment and nutrient loadings can harm ecosystems and affect the downstream usability of freshwater supplies. The impact of increased sediment and nutrient concentrations in freshwater systems has been extensively documented in the literature. In some extreme cases, it can lead to anoxic ‘dead zones’ in riverine, lacustrine, and marine habitats. Many river systems in Canada have shown elevated nutrient levels in recent years, often tied to the expansion of agricultural land use and destruction of natural forests to increasing nutrient levels in downstream rivers, lakes, and oceans. This study applies numerical modelling to quantify the influence of forest loss, agricultural expansion and the application of best management practices (BMPs) on water quality and quantity in the South Nation Watershed in eastern Ontario, Canada. The land use in the watershed is mainly agricultural (over 60%) with forest (27%) that is unevenly distributed in the basin. Aerial photography surveys from 2008 and 2014 show a steady decline in forest cover. Recent water quality monitoring has shown nutrient concentrations at or above Canadian water quality standards in many parts of the basin. The Soil and Water Assessment Tool (SWAT) was used to model the watershed because of its capacity to simulate comprehensive land management scenarios and assess their impact on a variety of water quantity and parameters quickly and effectively. The work was performed in four steps: 1. Recent land use configurations (2008-2014) in the watershed were acquired, and simplified land use projections based on the direct substitution of cropland for forest land were developed. 2. A numerical model was calibrated and validated for the initial land use scenario. 3. These land use scenarios, as well as more hypothetical scenarios representing more extensive deforestation and reforestation, were used as the basis for hydrological modelling using 31 years of real-world meteorological observations. 4. Idealized vegetated filter strips (VFSs) and grassed waterways (GWWs) were added to the cropped land packages to study the potential of these practices to contribute to the management of water quality. Analysis of the 33 output datasets derived from simulations of the suite of land use scenarios with and without VFSs and GWWs leads to several conclusions, while also raising some questions. Generally, forests significantly reduce sediment, nitrate and phosphorus outputs to streams as well as slightly reducing water yield compared to cropped areas due to an increase in surface runoff, groundwater and lateral flow combined with the absence of tile drainage. Across subbasins, this translates to significant reductions in sediment, nitrate and total phosphorus loadings entering the river reaches and a slight increase in water yield. At the basin outlet near Plantagenet, Ontario, streamflow and sediment loading show to have little sensitivity to changes in forest and crop cover, while increased forest cover leads to significantly reduced nutrient loadings, particularly in late spring and early winter. It is clear from this work that continued deforestation will continue to drive further nutrient enrichment in the South Nation River, while VFSs seems to have a significant potential for offsetting some of this enrichment. Streamflow and sediment loadings, however, are not significantly impacted by foreseeable deforestation. The influence of land use change and BMPs was much more significant in the runoff than in exports from the basin, suggesting there would be value in further examination of water quality and quantity at a higher spatial density to expand on assumptions of in-stream processes made here.
45

Identifikace a stabilizace drah soustředěného povrchového odtoku v povodí Prušánky a Mutěnického potoka / Identification and stabilization of concentrated runoff waterways in the watershed of Prusanka and Mutěnický creek

Horký, Štěpán January 2016 (has links)
The subject matter of the thesis is the identification of concentrated runoff waterways in the landscape and their consequent stabilization. The municipalities of Čejkovice and Mutěnice in the South Moravian region were analysed in order to reach this purpose. The thesis introduces theoretical bases for the definition of concentrated runoff waterways and their application in the calculation. The area was analysed on the basis of the digital elevation model in ArcGIS software environment. The CN curves method by means of the hydrological model DesQ – MAX Q was used for the calculation of concentrated runoff waterways.
46

Streambank stability in open channel drainage in the Ottawa-St. Lawrence lowlands

Mackie, Rob January 1988 (has links)
No description available.
47

[pt] OS RECENTES AVANÇOS DA MULTIMODALIDADE NO BRASIL / [en] THE RECENT ADVANCES IN BRAZILIAN MULTIMODALITY

ADRIANA FERREIRA PEDREIRA 02 August 2006 (has links)
[pt] O transporte é geralmente o elemento mais importante nos custos logísticos, para a maioria das empresas. A movimentação de fretes absorve, segundo Ballou (1993), entre um e dois terços do total de custos logísticos. Dentro desse panorama desenvolveu-se este estudo sobre multimodalidade. O foco está nas instalações e serviços que compõem o sistema de transporte multimodal, com especial destaque para a infra-estrutura portuária, nas taxas (custos) e no desempenho dos vários serviços envolvidos. O principal objetivo do trabalho é compreender como o processo de privatização das estruturas de transporte, portos, ferrovias e rodovias, viabilizou a evolução da Multimodalidade como alternativa ao transporte nacional. Um assunto relativamente novo, ainda pouco explorado academicamente e com escassas referencias bibliográficas. Para que se tenha um entendimento de como o processo de privatização transformou as estruturas de transporte, especialmente a atividade portuária brasileira, viabilizando o transporte multimodal e obviamente as vantagens dele decorrentes, fez- se necessária a abordagem de temas congruentes, como a logística e também os cenários dos modos de transporte rodoviário, ferroviário e o marítimo (cabotagem). Nesta fase também se analisam os modos de transporte e os respectivos processos de privatização e cenário atual, de suas estruturas e os operadores logísticos, assuntos que contribuem para um melhor entendimento das questões relativas ao Operador de Transporte Multimodal. / [en] Inside of this panorama this study was developed on multimodality. The focus is in the installations and services that compose the system of multimodal transport, with special prominence for the port infrastructure, in the taxes (costs) and the performance of the some involved services. The main objective of the work is to understand as the process of privatization of the transport structures, ports, railroads and highways, it made possible the evolution of Multimodalidade as alternative to the national transport. A relatively new subject, still little explored academically and with scarce bibliographical references. For a well understanding as the privatization process transformed the transport structures, especially the Brazilian port activity, making possible the multimodal transport and obviously the decurrently advantages of the boarding of congruence´s subjects became necessary, as logistic and also the scenes in the ways of road transport, railroad worker and the marine (cabotage). In this phase also the ways of transport and the respective processes of privatization and current scene are analyzed, of its structures and the logistic operators, subjects that contribute for one better agreement of the relative questions the Operator of Multimodal Transport.
48

Zpoplatnění vodní dopravní infrastruktury v EU / Charging of inland waterways in the European Union

Horynová, Dana January 2017 (has links)
Continuous growth in transport performance leads to deterioration of the transport infrastructure and there is also a need for states to raise funds to cover the costs of repairs, maintenance and modernization of this infrastructure. One option is to charge users of such infrastructure. In the Czech Republic there is a system of charges only for the use of road and rail transport routes. There is no charging of waterways in the Czech Republic, but it exists in some european countries. This diploma thesis deals with the issue of the charging of waterways in the European Union and thus points out the existence of an alternative possibility of financing expenditures for repairs, maintenance or modernization of the transport infrastructure serving the Czech water transport. The first three chapters contain the theoretical background, focusing in particular on the importance of freight water transport and European policy. The other chapters include an analysis of the established charging system for waterways in Germany. Subsequently, the total revenue from the charging of users of waterways for freight transport is calculated. From this analysis, the thesis is also based on the creation of a model for charging the Elbe waterway in the Czech Republic. After creating the preconditions for charging the Elbe waterway, the potential revenue obtained by this charging was also calculated and compared with the average annual cost of repairs and maintenance of watercourses in the Czech Republic.
49

Hydrodynamic analysis of inland vessel self-propulsion for cargo transport for navigability in the Magdalena River. / Análise hidrodinâmico da barcaça auto propelida para o transporte de carga para a navegabilidade no Rio Magdalena.

Acosta Lopera, Oscar David Acosta 27 May 2019 (has links)
The subject of this study is the determination of the resistance of an inland vessel engaged in cargo transport in the lower course of the Magdalena River, considering that the hydrodynamic effects in shallow water navigation are very different compared to the effects in deep water navigation. The hydrodynamic analysis is realized numerically using Computational Fluid Dynamics (CFD). The Reynolds-Averaging Navier-Stokes equation (RANS) solver is applied to simulate viscous and pressure effects around a tank and a hull in confined tank considering the wall bottom and side effects in shallow water navigation. For turbulence effects, realizable k-? model is used. The motion of the vessel causes elevations of the free surface, in which, is captured using the Volume of Fluid method (VOF). For discretization of flow domain, the Finite Volume Method (FVM) is applied. The motion of the fluids is updated for each time step that allows the calculation of the resistance acting on the hull. The numerical simulation results are compared with experimental data obtained by the Technological Research Institute of the State of São Paulo (IPT, acronym in Portuguese) together with the existing empirical methods for this type of cases. / É apresentado um estudo para determinar a resistência de uma barcaça empregada no transporte de carga que poderia operar no setor baixo do rio Magdalena. Os efeitos hidrodinâmicos de um navio em águas rasas são muito diferentes, comparados a esses efeitos em águas com profundidade infinita. A análise hidrodinâmica é realizada numericamente usando a Dinâmica dos Fluidos Computacional (CFD, acrônimo em inglês). A solução das equações de Navier-Stokes (NS) junto com a decomposição do Reynolds (RANS, acrônimo em inglês) é aplicada para simular os efeitos viscosos e de pressão em torno de um tanque e de uma embarcação em um tanque confinado que é caracterizado pelos efeitos do fundo e das paredes. Para efeitos de turbulência, o modelo realizado k-? é usado. O movimento da embarcação do rio provoca elevações da superfície livre que são capturadas usando o método do Volume de Fluido (VOF, acrônimo em inglês). Para a discretização do domínio de fluxo, o Método dos Volumes Finitos (FVM, acrônimo em inglês) é utilizado. O movimento dos fluidos é atualizado para cada intervalo de tempo o que permite o cálculo da resistência atuando no casco. Os resultados da simulação numérica são comparados com dados experimentais obtidos pelo Instituto de Pesquisas Tecnológicas do Estado de São Paulo (IPT), juntamente com os métodos empíricos existentes para esse tipo de casos.
50

A Modeling Study on The Effects of Seagrass Beds on the Hydrodynamics in the Indian River Lagoon

Unknown Date (has links)
Seagrass is a key stone component for the Indian River Lagoon (IRL) ecosystem, and therefore it is an important topic for many studies in the lagoon. This study focuses on the effects of seagrass beds on the hydrodynamics in the IRL. A hydrodynamic model based on the Delft3D modeling system has been developed for the southern IRL including the St. Lucie estuary, Ft. Pierce and St. Lucie Inlets, and adjacent coastal waters. The model is driven by freshwater inputs from the watershed, tides, meteorological forcing, and oceanic boundary forcing. The model has been systematically calibrated through a series of numerical experiments for key parameters, particularly the bottom roughness, and configuration including heat flux formulation and bottom bathymetry. The model skills were evaluated with quantitative metrics (point-to-point correlation, root-mean-square difference, and mean bias) to gauge the agreements between model and data for key variables including temperature, salinity, and currents. A three-year (2013-2015) simulation has been performed, and the results have been validated with available data including observations at HBOI Land-Ocean Biogeochemistry Observatory (LOBO) stations and in situ measurements from various sources. The validated model is then used to investigate the effects of 1) model vertical resolution (total number of model vertical layers), 2) spatial variability of surface winds, and 3) seagrass beds on the simulated hydrodynamics. The study focuses on the vicinity of Ft. Pierce Inlet, where significant seagrass coverage can be found. A series of numerical experiments were performed with a combination of different configurations. Overall, the experiment with 2-dimensional (2-D) winds, ten vertical layers and incorporating seagrass provided the most satisfactory outcomes. Overall, both vertical resolution and spatial variability of surface winds affect significantly the model results. In particular, increasing vertical resolution improves model prediction of temperature, salinity and currents. Similarly, the model with 2-D winds yields more realistic results than the model forced by 0-D winds. The seagrass beds have significant effects on the model results, particularly the tidal and sub-tidal currents. In general, model results show that both tidal and sub-tidal currents are much weaker due to increase bottom friction from seagrass. For tidal currents, the strongest impacts lie in the main channel (inter-coastal waterway) and western part of the lagoon, where strong tidal currents can be found. Inclusion of seagrass in the model also improves the simulation of sub-tidal currents. Seagrass beds also affect model temperature and salinity including strengthening vertical stratification. In general, seagrass effects vary over time, particularly tidal cycle with stronger effects seen in flood and ebb tides, and seasonal cycle with stronger effects in the summer than in winter. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

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