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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.
461

Estudo de via férrea lastreada sobre placa de concreto de cimento Portland / Study of ballasted track over concrete slab of Portland cement

Watanabe, Juliana Silva, 1978- 24 August 2018 (has links)
Orientador: Cassio Eduardo Lima de Paiva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-24T08:58:58Z (GMT). No. of bitstreams: 1 Watanabe_JulianaSilva_M.pdf: 2195811 bytes, checksum: 47a972a34bbdd51a602e9d71d473ff40 (MD5) Previous issue date: 2013 / Resumo: As ferrovias de carga pesada (heavy haul) têm como objetivo, trabalhar com grandes volumes de carga, mantendo uma velocidade que possibilite um tempo de percurso cada vez menor, mas esse deslocamento deve ser feito com segurança e para isso é necessário que a via permanente esteja sempre em condições aceitáveis de circulação. No Brasil, a estrutura atual desse tipo de via férrea atualmente está dimensionada para suportar aproximadamente até 32 toneladas por eixo, mas para favorecer o maior escoamento e tornar a ferrovia mais eficiente intenciona-se chegar a 40 toneladas por eixo. Baseado nessas informações, o objetivo deste trabalho foi analisar uma solução técnica de via férrea adequada para uma carga de 40 toneladas por eixo. Foram avaliadas duas situações: na primeira utilizou-se uma camada de lastro apoiada diretamente sobre a plataforma; e na segunda foi adotada uma placa de concreto de cimento Portland entre a camada de lastro e a plataforma da via. Para a primeira situação foram calculadas as tensões no trilho e na plataforma através dos modelos numéricos propostos por Eisenmann e Zimmermann, e na situação da placa de concreto, dimensionou-se uma estrutura baseada no método de dimensionamento de pisos industriais da Associação Brasileira de Cimento Portland. Para os dois casos, as tensões atuantes na via permanente foram verificadas através do programa computacional FERROVIA. As conclusões foram obtidas através de comparações entre os valores das tensões calculados pelos métodos teóricos e pelo método computacional / Abstract: The heavy haul lines objective is to carry elevated freight, maintaining speeds that assure a shorter travel time. It must be done safely and, for this, it is required good conditions for the track. This Brazilian railway structure is designed to support 32 tonnes per axle, however to promote a better flow and to become more efficient there is an intention of change this freight to 40 tonnes per axle. Based on that, the aim of this study was to analyze a suitable technical solution t for 40 t/ axle load. Two situations have been evaluated: in one of them it was used a ballast layer over the formation; and in the other one it was adopted a concrete slab between the ballast layer and the formation. For the first situation stresses on rail and formation were calculated based on the theoretical models (Zimmermann and Eisenmann methods), and for the second one, a structure similar to a concrete pavement has been designed (ABCP industrial floor method). For both cases, the tresses on the track have been verified by the computational program FERROVIA. The conclusions were based on comparisons between the stresses values calculated by the theoretical and computational methods / Mestrado / Transportes / Mestra em Engenharia Civil
462

The underground railroad

Gleason, Johanna 01 January 1993 (has links)
No description available.
463

[en] DECISION SUPPORT SYSTEM FOR THE OPERATIONAL CONTROL CENTER IN THE RAILROAD TRAFFIC MANAGEMENT / [pt] SISTEMA DE APOIO À DECISÃO AO CENTRO DE CONTROLE OPERACIONAL NO GERENCIAMENTO DO TRÁFEGO FERROVIÁRIO

LUCIANA SILVEIRA NETTO NUNES 26 May 2004 (has links)
[pt] Esta pesquisa tem por objetivo conceber um sistema de apoio à decisão ao centro de controle operacional no gerenciamento do tráfego ferroviário. O sistema consiste na resolução de conflitos entre trens. Esta pesquisa justifica- se devido à deficiência encontrada pelos controladores de tráfego na tomada de decisões. Atualmente, as prioridades dos trens são pré-estabelecidas e, a partir da análise de um gráfico feito à medida que os eventos ocorrem, o planejamento do despacho de trens é realizado. As prioridades podem ser modificadas ao longo do dia, a partir de alguma ordem superior. Assim, existe a necessidade do desenvolvimento de um novo sistema que auxilie os controladores de tráfego na determinação da melhor solução para os conflitos entre trens. Inicialmente, foram realizados os levantamentos bibliográficos e de dados. Na revisão bibliográfica, foram analisados o sequenciamento de trens, condições de ultrapassagem e de cruzamentos e modelos de programação de trens. Em seguida, foi aplicada uma heurística proposta por Leal (2003) desenvolvida a partir da formulação de Szpigel (1972) e implementada em um programa de computador, na linguagem delphi. Esta heurística apresenta uma solução para os conflitos entre trens. A aplicação foi baseada nos dados fornecidos pela empresa MRS logística, situada em Juiz de Fora (MG). A partir da solução gerada por Leal (2003), foi desenvolvido um gráfico no Excel, utilizando a linguagem visual basic, onde são analisadas as programações dos trens com a solução dos conflitos. O objetivo final desta pesquisa é sugerir uma ferramenta de auxílio para o gerenciamento do tráfego ferroviário, contribuindo para a evolução e eficiência das ferrovias no Brasil. / [en] The objective of this research is to conceive a decision support system for the operational control center in the railroad traffic management. The system consists of the resolution of conflict between trains. The justification of this research is due to the deficiency founded by controllers of traffic in the decisions making. Currently, the trains priorities are previously established and, through the analysis of a done graph to the measure that the events go happening, these priorities can be modified. Thus, there is the necessity of the development of a new system which helps the controllers in the determination of the best alternative. Initially, the bibliographical surveys and the data-collectings had been made. In the bibliographic revision, the sequenciament of trains, ultraticket and crossing conditions, and trains programming models had been analyzed. The next step was the application of an heuristic developed by Leal (2003), based in the formularization of Szpigel (1972), and implemented in a computer program, in the Delphi language, showing the solution of conflicts between trains. The application was based in the data of MRS logistic company, situated in Juiz De Fora (MG). From the solution generated for Leal (2003), a graph in the excel was developed, using visual basic language, and shows the programmings of the trains with conflits solution. The final objective is to suggest a tool for helping the railroad traffic management, contributing for the evolution and efficiency of the railroads in Brazil.
464

The Economic Development of the Rio Grande Plain

Masters, Noble M. 08 1900 (has links)
The study of the economic development of the Rio Grande Plain has been divided into the following seven chapters: (1) Physical Aspects of the Rio Grande Plain, (2) Grazing, (3) Development of Farming, (4) Development of Transportation, (5) Growth of Major Urban Centers, (6) Development of Natural Resources, and (7) Present Trends. In each chapter except Chapters I and VII, effort has been made to locate the origin of that particular industry and trace its development. In order to understand the development in the raising of livestock, farming, transportation, natural resources, and the growth of major cities of the region, it would be well to understand the physical aspects of the region.
465

Creating a Maine railroad landscape, 1890-1897: architecture of the Portland & Rumford Falls Railway and the Rumford Falls & Rangeley Lakes Railroad

Stevenson, Charles Ian 22 January 2016 (has links)
In 1890, paper magnate Hugh Chisholm chartered the Portland & Rumford Falls Railway to provide service between Maine's largest city and the nascent industrial community of Rumford Falls. From 1890 to 1897, directors of that railroad embarked upon a cohesive building program to distinguish its stations from competitors and to attract traffic to Rumford Falls. This railroad's program represents a seminal moment in small town railroad station architecture because it was an early manifestation of a planned, replicated design. Civil engineer Frederic Danforth implemented the comprehensive landscape developed by architect Edwin Lewis. This pattern of architect-driven designs would be developed in the early twentieth century by railroad companies nationwide as they more aggressively created corporate branding, while also balancing community relations. In 1894, Chisholm and associates chartered a second rail line, the Rumford Falls & Rangeley Lakes Railroad, to service nearby timberlands and outdoor sporting locales. This line would further increase the prowess of Rumford Falls and the profitability of the Portland & Rumford Falls Railway. Lewis was not associated with this project, but its directors maintained a complementary architectural program almost indistinguishable from the earlier campaign. This thesis examines the initial development of the two rail lines based on photographs, architectural drawings, and documentary research. It explores how these building programs fit into the greater schema of corporate railroad architectural development. It elucidates the national trends toward an interconnected industrial landscape and early attempts at corporate branding through vernacular architecture.
466

Groundwater Vulnerability Assessment for Railroad Construction in Stockholm, Sweden, using Spatial Multi Criteria Analysis.

Tsoy, Irina January 2015 (has links)
The environmental impact of transportation construction, operation and maintenance is of critical importance. Therefore it is vital to carry out a groundwater vulnerability assessment for transportation projects at an early stage. The objective of the study was to apply a methodology for groundwater vulnerability assessment for transportation planning in order to identify and avoid areas susceptible to contamination. In this study a spatial multi criteria analysis (SMCA) was conducted where the impacts of railroads on groundwater were examined. Physical factors that influence the groundwater vulnerability such as infiltration capacity, hydraulic conductivity, effective porosity, slope, land cover, depth to groundwater and topographic wetness index (TWI) were considered in this study. Results from the study show that about 30% of the total area was prone to high and very high groundwater vulnerability. The final vulnerability map illustrated the highly vulnerable areas in the sand deposits and till and less vulnerable areas of rock outcrops and clay deposits. According to the outcome of the sensitivity analysis the methodology used in this study shows promising results and can be employed further with some improvements. / På grund av ökad efterfråga på transport planerar Stockholms Lokaltrafik (SL) en ny järnväg i norra Stockholm mellan Vallentuna kommun och Arlanda flygplats (Sveriges största internationella flygplats). Väg- och järnvägskonstruktion och underhåll förorenar inte bara luft, mark och närliggande vattendrag utan även den mättade zonen genom infiltrerande vatten. Denna studie fokuserar på effekterna av järnvägen på grundvattnet, eftersom grundvatten är en viktig resurs för vattenförsörjning (hushåll, industri etc.) Syftet med denna studie var att utveckla en modell för sårbarhetsanalys av grundvatten för transportplanering genom Multi Criteria Analysis (MCA) och geografiska informationssystem (GIS). För att hantera detta komplexa problem har sju kriterier kritiska för grundvattnets sårbarhet identifierats (t.ex. hydraulisk konduktivitet, infiltration och effektiv porositet, djup till grundvatten, marktäcke, topografisk wetness index (TWI) och lutning); viktats med tanke på dess påverkan på grundvattnet och dess noggrannhet i data; och till sist kombinerats för att framställa en grundvattensårbarhetkarta. GIS (ArcGIS) verktyg användes i studien för att hantera rumslig heterogenitet inom det studerade området samt komplexiteten av MCA. För att utvärdera påverkan av varje kriterium på resulterad sårbarhetskarta tillämpades enda variabel metoden. Genom att jämföra värdena från den teoretiska viktningen (tilldelade värden) och den effektiva viktningen (beräknade värden) för varje kriterium kunde det mest inflytelserika kriteriet identifieras. Som ett resultat av studien, producerades en grundvattensårbarhetskarta över det studerade området vilket indikerade att sand och moränavlagringar är mycket känsliga för föroreningar på grund av hög infiltrationskapacitet i grovkornig jord, högt värde av hydraulisk konduktivitet och effektiv porositet. Men på grund av låg infiltration och hydraulisk konduktivitet tillsammans med låg effektiv porositet, erhöll lera som ligger på låga upphöjda områden det lägsta värdet av sårbarhet.
467

Defect Detection on Rail Base Area Using Infrared Thermography

Shrestha, Survesh Bahadur 01 September 2020 (has links)
This research aims to investigate the application of infrared thermography (IRT) as a method of nondestructive evaluation (NDE) for the detection of defects in the rail base area. Rails have to withstand harsh conditions during their application. Therefore, defects can develop in the base area of rails due to stresses such as bending, shear, contact, and thermal stresses, fatigue, and corrosion. Such defects can cause catastrophic failures in the rails, ultimately leading to train derailments. Rail base defects due to fatigue and corrosion are difficult to detect and currently there are no reliable or practical non-destructive evaluation (NDE) methods for finding these types of defects in the revenue service. Transportation Technology Center, Inc. (TTCI) had previously conducted a research on the capability of flash IRT to detect defects in rail base area based on simulation approach. The research covered in this thesis is the continuation of the same project.In this research, three rail samples were prepared with each containing a notched-edge, side-drilled holes (SDHs), and bottom-drilled holes (BDHs). Two steel sample blocks containing BDHs and SDHs of different sizes and depths were also prepared. Preliminary IRT trials were conducted on the steel samples to obtain an optimal IRT setup configuration. The initial inspections for one of the steel samples were outsourced to Thermal Wave Imaging (TWI) where they employed Thermographic Signal Reconstruction (TSR) technique to enhance the resulting images. Additional inspections of the steel samples were performed in the Southern Illinois University-Carbondale (SIUC) facility. In case of the rail samples, the SDHs and the notched-edge reflectors could not be detected in any of the experimental trials performed in this research. In addition, two more rail samples containing BDHs were prepared to investigate the detection capabilities for three different surface conditions: painted, unpainted, and rusted. The painted surface provided a best-case scenario for inspections while the other conditions offered further insight on correlating the application to industry-like cases.A 1300 W halogen lamp was employed as the heat source for providing continuous thermal excitation for various durations. Post-processing and analysis of the resulting thermal images was performed within the acquisition software using built-in analysis tools such as temperature probes, Region of Interest (ROI) based intensity profiles, and smoothing filters. The minimum defect diameter to depth (aspect) ratio detected in preliminary trials for the steel sample blocks were 1.0 at a diameter of 4.7625 mm (0.1875 in) and 1.5 at a diameter of 3.175 mm (0.125 in). For the inspection of painted rail sample, the longest exposure times (10 sec) provided the best detection capabilities in all sets of trials. The three holes having aspect ratio greater or equal to 1.0 were indicated in the thermal response of the painted and rusted samples while only the two holes having aspect ratio greater or equal to 1.5 were indicated in the unaltered sample. Indications of reflectors were identified through qualitative graphical analysis of pixel intensity distributions obtained along a bending line profile. The results obtained from the painted sample provided a baseline for analyzing the results from the unpainted and rusted rail samples. This provided an insight on the limitations and requirements for future development. The primary takeaway is the need for an optimized heat source. Poor contrast in the resulting image for the unpainted and rusted rail samples is experienced due to both noise and lack of penetration of the heat energy. This could have been due to decreased emissivity values. Moreover, the excitation method employed in this research does not comply with current industry standards for track clearances. Therefore, exploration of alternative excitation methods is recommended.
468

The Political Economy of Value Capture: How the Financialization of Hudson Yards Created a Private Rail Line for the Rich

Petretta, Danielle Lucia January 2020 (has links)
Abstract: The theory of value capture is simple to understand and easy to sell, promising self-fulfilling virtuous cycles of value generation, capture, and redistribution. Countless studies document value creation attributable to public interventions, providing guidance on the type and extent of potential benefits. Scholars too have set forth parameters for optimal value capture conditions and caution against common pitfalls to keep in mind when designing value capture plans. But even when utilizing the best advice, equitable redistribution of benefits rarely occurs in neoliberal economies, leaving municipalities struggling to meet the myriad of social needs and provide basic services for all their inhabitants. Invariably, capitalistic real estate states seek to financialize public assets for private gain. Nowhere is this more apparent in New York City today than in the outcomes thus far of one of the largest public-private developments in New York history at Hudson Yards. This dissertation documents the failure of the value capture scheme put in place at Hudson Yards which neither captured fair market value for the public, nor extracted much public benefit. The scheme aimed to leverage vast tracts of publicly-owned land above operational rail yards at the Far West Side of Manhattan. Instead, public action under the guise of public purpose catalyzed the private financialization of a finite public asset, through the seemingly benign but inherently complex public policy tool of value capture finance. In particular, this dissertation tells the detailed development story of Hudson Yards, where developers reap huge rewards for their risks while the public still waits for what was promised — an all too familiar story.
469

A History of John W. Young's Utah Railroads, 1884-1894

Adkins, Marlowe C., Jr. 01 May 1978 (has links)
The purpose of this paper is to recount how, under the entrepreneural guidance of John Willard Young, three narrow gauge, shortline railroads were established in and near Salt Lake City, Utah between 1884 and 1894. Once justification for these projects was ascertained, the problems created by local and national politics, construction, and financing were met in a satisfactory manner. The results were two operating railroads and roadbed established for a third line. Operations continued under the control of John W. Young until the depression of 1893 when these railroads went into receivership.
470

Petrology of Mineralized and Non-Mineralized Samples from the Railroad District within the Carlin Trend, Elko, NV

Dvorak, Katherine A. 21 May 2013 (has links)
No description available.

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