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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.
1

Maglev high speed ground transportation for the Texas Triangle : a technology assessment

Rojas, Gabriel, active 2007 20 November 2013 (has links)
A maglev rail network connecting the Texas Triangle has the ability to unite this emerging mega-region with a highly efficient alternative to auto and air transport. This would serve to increase the economic sharing of resources and will improve the quality of life for residents with enhanced accessibility to jobs and services in all triangle cities. Many unforeseen benefits materialize from such a highly connected regional transportation infrastructure including cost reductions in highway maintenance and construction and reduced air traffic in congested skies and airports. This study examines the reasons for choosing a maglev system, regulatory barriers to implementing such a system, and the costs associated with a Maglev system built in the Texas Triangle. / text
2

Freight rail public-private partnerships : how Texas may accommodate the future surge in growth

Demars, Chelsea Elizabeth 14 November 2013 (has links)
This report assesses the current and future freight conditions in Texas, and how more freight will need to be transported by rail to keep up with the population and economic trends. Public-private partnerships are necessary to accommodate this surge in growth in order to make it financially feasible for both the public and private sectors. The intent of this report is to introduce the concept of freight rail public-private partnerships in order to relate it to the State of Texas to help accommodate growth. Two case studies will be discussed as examples of successful public-private partnerships where freight rail expansion was feasible. At the end of each case study, there is a section for implications in Texas’ rail system. A series of interviews with public and private stakeholders will portray the sides of both sectors as to why freight rail publicprivate partnerships are difficult to achieve in Texas. Finally, some recommendations will be made for Texas based on the case studies and interviews. / text
3

Agent based micro-simulation of a passenger rail system using customer survey data and an activity based approach

Makinde, O., Neagu, Daniel, Gheorghe, Marian 11 August 2018 (has links)
No / Passenger rail overcrowding is fast becoming a problem in major cities worldwide. This problem therefore calls for efficient, cheap and prompt solutions and policies, which would in turn require accurate modelling tools to effectively forecast the impact of transit demand management policies. To do this, we developed an agent-based model of a particular passenger rail system using an activity based simulation approach to predict the impact of public transport demand management pricing strategies. Our agent population was created using a customer/passenger mobility survey dataset. We modelled the temporal flexibility of passengers, based on patterns observed in the departure and arrival behavior of real travelers. Our model was validated using real life passenger count data from the passenger rail transit company, after which we evaluated the use of peak demand management instruments such as ticketing fares strategies, to influence peak demand of a passenger rail transport system. Our results suggest that agent-based simulation is effective in predicting passenger behavior for a transportation system, and can be used in predicting the impact of demand management policies.
4

Estimativa de emissão de gases de efeito estufa na operação do sistema ferroviário da região metropolitana de João Pessoa – Paraíba, Brasil.

SOARES, Diogo da Fonseca. 12 September 2018 (has links)
Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-09-12T18:29:18Z No. of bitstreams: 1 DIOGO DA FONSECA SOARES – DISSERTAÇÃO (PPGRN) 2018.pdf: 725145 bytes, checksum: 093573006141a5435aa2269250c27783 (MD5) / Made available in DSpace on 2018-09-12T18:29:18Z (GMT). No. of bitstreams: 1 DIOGO DA FONSECA SOARES – DISSERTAÇÃO (PPGRN) 2018.pdf: 725145 bytes, checksum: 093573006141a5435aa2269250c27783 (MD5) Previous issue date: 2017-12-13 / O presente estudo objetivou inventariar as emissões de Gases de Efeito Estufa (GEE) do sistema ferroviário da região metropolitana de João Pessoa no ano base de 2016. Seguiuse a metodologia do Programa Brasileiro GHG Protocol versão 2016 para quantificar as emissões. As fontes emissoras foram organizadas de acordo com os limites operacionais classificados nos escopos 1, 2 e 3. A emissão total no ano inventariado foi de 1.035,76 tCO2e e 73,26 tCO2 biogênico. A fonte que mais contribuiu nas emissões foi a combustão ferroviária com 981,05 tCO2e, seguida da geração de energia elétrica 22,67 tCO2e. Considerando a interdisciplinaridade desta pesquisa, compreende que o estudo dos impactos atmosféricos do sistema de trem de João Pessoa serviu como parâmetro para o delineamento de estratégias e técnicas de mitigação da poluição do ar no Estado da Paraíba, tal como a melhoria de qualidade de vida para gerações vindouras. / The present study aimed to inventory Greenhouse Gas (GHG) emissions from the rail system of the metropolitan region of João Pessoa in the base year of 2016. The methodology of the Brazilian GHG Protocol version 2016 was followed to quantify emissions. The issuing sources were organized according to the operational limits classified in scopes 1, 2 and 3. The total emission in the inventoried year was 1,035.76 tCO2e and 73.26 tCO2 biogenic. The source that most contributed to the emissions was the railway combustion with 981.05 tCO2e, followed by the generation of electric energy 22.67 tCO2e. Considering the interdisciplinary nature of this research, it is understood that the study of the atmospheric impacts of the João Pessoa train system served as a parameter for the design of strategies and techniques to mitigate air pollution in the State of Paraíba, such as improving the quality of life for generations to come.
5

The New Harmony: An Adaptive Reuse Transit Hub

Blake, Michael Joseph 09 October 2008 (has links)
The development of jazz during the American industrial revolution represents a broader shift in the zeitgeist of the New World. With a rich heritage of rhythmic emphasis in both art and life, African American jazz musicians were able to internalize the increasingly polyrhythmic nature of the metropolis, and groove with the potentially oppressive presence of the machine. Their brazen embrace of the temporal encouraged artists of all media, replacing the burden of permanence and exactitude with the fearlessness of an improvising jazz soloist. The jazz-inspired works of Le Corbusier and Piet Mondrian, for example, explored a synesthetic relationship between the visual and the audible has captured the imagination of the great artists, musicians, architects, and philosophers throughout the history of culture. My thesis exploration attempts to continue this tradition in the context of an increasingly accelerating speed of life, and the new, environmentally sensitive role of the machine. Just as Jazz poeticized the hectic rhythms of the industrial age, I believe that architecture should be conceived of as a synchronizing element within the contemporary urban landscape. Through my design of an adaptive reuse transit hub, my intent was to embrace the temporal in a manner that not only reflects the spirit of the age, but also creates musical architecture. / Master of Architecture
6

Regula????o e desempenho de servi??os p??blicos em regime de concess??o: an??lise do transporte ferrovi??rio de cargas no Brasil p??s-privatiza????es

Souza J??nior, Marcos Sim??o de January 2013 (has links)
Submitted by Gustavo Gomes (gustavolascasas@gmail.com) on 2013-11-12T12:16:33Z No. of bitstreams: 1 Regula????o e desempenho de servi??os p??blicos em regime de concess??o.pdf: 12414617 bytes, checksum: baeb55ebaa9a6b037cc50d7240b32e4a (MD5) / Approved for entry into archive by Roger Guedes (roger.guedes@fjp.mg.gov.br) on 2013-11-13T18:20:45Z (GMT) No. of bitstreams: 1 Regula????o e desempenho de servi??os p??blicos em regime de concess??o.pdf: 12414617 bytes, checksum: baeb55ebaa9a6b037cc50d7240b32e4a (MD5) / Made available in DSpace on 2013-11-13T18:20:45Z (GMT). No. of bitstreams: 1 Regula????o e desempenho de servi??os p??blicos em regime de concess??o.pdf: 12414617 bytes, checksum: baeb55ebaa9a6b037cc50d7240b32e4a (MD5) Previous issue date: 2013 / - / O desenvolvimento do transporte ferrovi??rio no Brasil teve diferentes fases, que foram marcadas por distintas formas de participa????o do Estado na provis??o e regula????o desse servi??o p??blico (incluindo o per??odo em que o mesmo acumulou as duas fun????es, entre as d??cadas de 1950 e 1990). Os graves problemas estruturais e financeiros que atingiram o sistema ferrovi??rio brasileiro a partir da d??cada de 1980 levaram o setor a ser privatizado na d??cada seguinte. Nesse ??nterim, a desestatiza????o do sistema ferrovi??rio brasileiro acompanhou uma tend??ncia internacional de privatiza????o e desregulamenta????o de setores de infraestrutura, o que ocorreu no rastro das reformas de orienta????o neoliberal promovidas ap??s a deflagra????o da crise do Estado na d??cada de1970. Nesse novo contexto, a regula????o deve, fundamentalmente, ter a miss??o de incentivar e garantir os investimentos necess??rios, proteger os usu??rios, promover o bem-estar da sociedade e aumentar a efici??ncia da presta????o desse servi??o p??blico. Nesse sentido, a reestrutura????o do sistema ferrovi??rio brasileiro implicou no estabelecimento de um marco regulat??rio, que, atualmente, vem sendo revisado e aperfei??oado. O presente trabalho tem como objetivo mais geral analisar a rela????o entre a regula????o (especialmente o marco regulat??rio) do transporte ferrovi??rio de cargas brasileiro e o desenvolvimento do setor no per??odo p??s-privatiza????es. Nesse sentido, s??o examinados os alcances e limites do marco regulat??rio, institu??do no bojo das privatiza????es, no que tange ?? promo????o dos objetivos e fins pretendidos com a regula????o do servi??o p??blico de transporte ferrovi??rio de cargas, quais sejam garantir a viabilidade econ??mica da atividade, criar condi????es para investimentos em melhoria e expans??o de sua presta????o e, notadamente, assegurar a observ??ncia do interesse p??blico no que diz respeito ao padr??o de oferta (em termos de regularidade, efici??ncia e de aumento da produ????o e da qualidade da oferta). Constatou-se que a regula????o p??sprivatiza????o foi capaz de viabilizar a consecu????o de alguns avan??os importantes em termos de aumento global da produ????o ferrovi??ria e da seguran??a do transporte ferrovi??rio de cargas (aspectos parametrizados do marco regulat??rio), mas fracassou ao n??o evitar a ocorr??ncia de distor????es como a baixa competitividade, a pouca integra????o da malha e a forte concentra????o de investimentos, de tipos de cargas transportadas e da utiliza????o efetiva da malha em poucos trechos de maior rentabilidade comercial para as empresas. A an??lise empreendida no trabalho sugere que o padr??o de oferta do transporte ferrovi??rio de cargas se aproximou muito mais dos objetivos empresariais das concession??rias, que, de acordo com a sua l??gica comercial, tendem a explorar a malha ferrovi??ria apenas nos trechos (e para o transporte das mercadorias) que lhes sejam mais rent??veis, do que do interesse p??blico, que envolve, conforme cunhado na abordagem te??rica da regula????o, a presta????o do servi??o de forma eficiente (cujos custos e benef??cios garantam o bem-estar da sociedade), em condi????es adequadas de disponibilidade e qualidade e, n??o menos importante, com vistas ?? sua expans??o e ?? modicidade das tarifas cobradas pela sua presta????o. / The development of rail transport in Brazil had different phases, which were marked by various forms of state participation in the provision and regulation of this utility (including the period in which it accumulated the two functions, between the 1950s and 1990). The severe financial and structural problems that hit Brazil's railway system from the 1980s led the industry to be privatized in the next decade. Meanwhile, the privatization of the Brazilian railway system followed an international trend of deregulation and privatization of infrastructure sectors, which occurred in the wake of neoliberal reforms promoted after the outbreak of the crisis in the state de1970 decade. In this new context, the regulation should basically have the mission to encourage and ensure the necessary investments, protect users, promote the welfare of society and increase efficiency in the delivery of public services. In this sense, the restructuring of the Brazilian railway system resulted in the establishment of a regulatory framework, which currently is being revised and improved. The present study aims to examine the relationship between regulation (especially the regulatory framework) of the Brazilian rail freight and the development of this sector in the post-privatization. Accordingly, we examine the reaches and limitations of the regulatory framework established in the wake of privatization, when it comes to promoting the goals and purpose with the regulation of public rail cargo, namely ensuring the economic viability of the activity, create conditions for investment in improving and expanding its provision and, in particular, ensure compliance with public interest as regards the standard offer (in terms of regularity, efficiency and increased production and quality of its supply). It was found that the post-privatization regulation was able to facilitate the achievement of some important advances in terms of global increased of the production and the safety of rail freight (parameterized aspects of the regulatory framework), but failed to prevent the occurrence of some distortions such as low competitiveness, poor integration of the railway network and the strong concentration of investments, types of cargo carried and the effective use of the railway network in a few rail stretch largest commercial profitability for companies. The analysis in this paper suggests that the pattern of provision of rail freight approached more of the business objectives of the concessionary companies, which, according to your business logic, tend to explore the railway only in rails stretch (and for transportation of the goods) which are more profitable, than the public interest, which involves, as coined in the theoretical approach of regulation, the provision of the utility efficiently (whose costs and benefits ensure the well-being of society), under appropriate conditions availability and quality and, not least, with a view to its expansion and the reasonableness of the fees charged for its provision. / Economia e Finan??as
7

Konstrukční úprava upínaní tlakových zásobníků vstřikovacího systému Common Rail při výrobě / Rail Production Machine Clamping Device Design Modification

Sedláček, Tomáš January 2014 (has links)
The present master’s thesis deals with the appropriate measuring methods to determine the technical state of the machine tool for production of pressure tanks of Common Rail injection system. The main topic of this thesis is also a constructional adjustment of problem clamping components whose function affects the quality of the pressure tank.
8

Analýza vlivu funkčních parametrů na těsnost nízkotlakého konektoru Common Railu / Analysis of the influence of the Common Rail low-pressure connector parametres on its leak tightness

Ščerban, Bedřich January 2020 (has links)
The aim of this theses is a sensitivity analysis of the tightness properties of the press-fit joined of the fuel pressure vessel Common Rail and the low pressure connector. Possible solutions were analyzed, where the fractional factorial design of a numerical experiment resolution four was chosen. Results of the thesis are statistically significant factors used in formulating the construction change recommendations.
9

Analýza vzniku sloučenin fosforu při procesech tepelného zpracování / Analysis of Iron-Phosphorus Reaction Products Formation During Heat Treatment Processes

Skoumalová, Zuzana Unknown Date (has links)
During high pressure pulsation tests repeated cracks of CP3. housings occur. High pressure pump CP3 is part of injection system Common Rail. Cracks can be caused by segregation of phosphorous from a washing medium on grain boundaries during subsequent heat treatment process. The present master´s thesis focuses on analysis of phosphorous compounds on specimen surface made from steel 20MnCr5, which were soaked in solutions with different concentration of phosphorous. Master’s thesis is also focused on potencial influence of phosphorous on structure and properties of this material. The first part of the thesis provides a summary of current knowledge in the studied field, experimental results can be found in the second part. The surface analysis XPS, the light microscopy, the scanning electron microscopy equipped by energy dispersive chemical analysis, the glow discharge optical emission spectroscopy, the methods of the phase analysis by means of the X-ray diffraction and impact test were used.
10

<b>Design and Control of a Multi-Pressure Rail System for Agricultural Vehicles</b>

Xiaofan Guo (18404121) 18 April 2024 (has links)
<p dir="ltr">Hydraulic actuation technology is one of the most common ways of transferring power in agricultural and construction machinery. As the system efficiency and fuel consumption of these machines gains more attention due to climate change, a new generation of high-efficient hydraulic architecture is in need. This dissertation presents a study for reducing energy loss in the hydraulic control system of agricultural tractors and their implements. The solution is referred to as a multi-pressure rail (MPR) system and provides power to the hydraulic functions following a pressure control logic, as opposed to the traditional flow control logic typical of hydraulic systems used in off-road vehicles.</p><p dir="ltr">The proposed hydraulic architecture and controller allows for elimination of redundant flow control valves in the state-of-the-art system, which cause excessive throttling losses leading to poor overall energy efficiency. Related work on MPR technology targets construction vehicles, where the MPR solution can allow energy recovery during overrunning loads and better engine management. This study alternatively addresses the case of agricultural applications where functions mostly operate under resistive load conditions with slow dynamics, which offers an opportunity to target throttle losses. The hydraulic architecture design starts with the choice of number of rails, then supply system and pressure selection and control valve set. Next, the controller is proposed. The controller contains two layers. The lower layer directly controls the command tracking, rotational speed, or pressure, for each subsystem. The higher layer, namely the supervisory controller, optimizes the rail pressure levels in real time to guarantee minimum overall throttling loss.</p><p dir="ltr">To prove the effectiveness of the hydraulic system architecture and controller design, a standalone test rig was conceived and used to validate a numerical simulation model of the MPR system and its control strategy. Particular focus is given to the dynamic behavior of the system during the switches of a function between different pressure rails, which needs to ensure reduced oscillations of the flow provided to each hydraulic function. Then, to demonstrate the ability on power saving in real working conditions, reference machines were chosen: a 435 hp hydraulic tractor powering a 16-row planter, for which operating features during typical drive cycles were available to the authors. Simulation models of the two reference machines were built and validated with in field experiments. A full MPR system model on the reference machines was constructed using the validated models. This full model was used to predict the reference tractor and planter hydraulic system performance and power consumption during typical drive cycles. The results show up to 52.4% total power reduction at the pump shaft, corresponding to 113.8% system efficiency gain.</p><p dir="ltr">The dissertation also laid out the planned activities to complete the study. The system controller will be generalized that could suit more equipment in addition to the reference machine in this study. In the meantime, the reference tractor and planter will be modified into the proposed MPR system for field testing. That includes new sensors, controllers, valves, etc. The field test is the final experimental validation for the proposed MPR system on the front of effectiveness and power saving in real working condition.</p>

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