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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.
511

Effect of Forming Process on the Deformational Behaviour of Steel Pipes

Tanbakuei Kashani, Majid January 2017 (has links)
Buried pipeline networks play a vital role in the transportation of oil and natural gas from centers of production to centers of consumption. A common manufacturing technique for such pipes is the UOE process, where a flat steel plate is first formed into a U shape, then into an O shape, welded at the seam, and mechanically expanded before being shipped on site. The UOE forming process deforms the pipe material plastically and induces residual strains in the pipe. Such pipes are commonly buried on side and then are pressurized under the high head of the fluids they convey which induce hoop stresses as high as 80% of the pipe yield strength. When buried pipelines cross the regions of discontinuous permafrost, they undergo differential frost heaving, inducing significant bending deformations, which potentially induce local buckling in the pipe wall. To control local buckling, design standards impose threshold limits on buckling strains. Such threshold values are primarily based on costly full-scale experimental results. Past nonlinear finite element analysis attempts aiming at determining the threshold buckling strains have neglected the presence of residual stresses induced by the UOE forming and were thus found to grossly overestimate the buckling strains compared to those based experiments. Within the above context, the present study focuses on developing a numerical technique to predict the residual stresses induced during UOE forming, and incorporating the induced residual stresses in 3D nonlinear FEA modeling to more reliably predict buckling strain limits. Comparisons with conventional analysis techniques that omit residual stresses reveal the importance of incorporating residual stresses induced in forming when quantifying buckling strains.
512

Prioritization of Potable Water Infrastructure Investments on the Navajo Nation

Chee, Ronson Riley, Chee, Ronson Riley January 2017 (has links)
Notorious for its high poverty levels and low socio-economic status, the Navajo Nation’s socio-economic well-being is hindered greatly in part by the lack of an adequate potable water infrastructure which has resulted in health disparities and has attributed to stunted economic growth within the Nation. Large candidate regional water transmission pipelines projects aimed to meet these needs have been identified. With capital costs exceeding their fiscal capability, decision-makers must choose projects that generate the most bang for the buck. To address these challenges, three (3) interconnected planning tools have been developed: (1) a water pipe installation construction cost estimation model (WaterCOSTE) to improve the accuracy of capital cost estimates; (2) a hydraulic optimization model (WaterTRANS) that improves design efficiency for branched water transmission systems; and (3) a decision support system (DSS) that allows candidate water transmission projects to be ranked while considering economic development, health improvement and environmental protection objectives. Estimates derived from WaterCOSTE are used as input into WaterTRANS to find least-cost system designs. The system costs along with other project data are then input into the DSS to determine project rankings. To demonstrate how the DSS can be used and applied, two candidate projects on the Navajo Nation are evaluated. The tools developed will enable decision-makers to improve planning processes and make wiser investment decisions that will lead to expanding the water infrastructure coverage and living conditions on the Navajo Nation.
513

Conflitos e contratos: a Petrobras, o nacionalismo boliviano e a interdepedência do gás natural (2002-2010) / Conflicts and contracts: Petrobras, Bolivian nationalism and interdependence of natural gas (2002-2010)

Igor Fuser 20 September 2011 (has links)
A nacionalização dos hidrocarbonetos pelo presidente boliviano Evo Morales, em maio de 2006, provocou a mais séria crise na política externa brasileira durante o primeiro mandato presidencial de Lula. A decisão prejudicou os interesses da Petrobras, na época a maior empresa instalada na Bolívia, com presença em todos os ramos da atividade petroleira. O conflito foi amplificado pela existência de uma relação de interdependência entre os dois países com base no gasoduto de 3.150 quilômetros, que transporta quase a metade do gás natural consumido pela indústria no Brasil. Com a nacionalização sem expropriação, segundo a fórmula adotada por Morales, as empresas estrangeiras foram autorizadas a permanecer na Bolívia, mas tiveram de renegociar seus contratos, aceitando a ampliação da receita fiscal (government take) obtida pelo governo a partir da produção petroleira. Essa decisão do governo boliviano expôs as contradições da política do Brasil para a América do Sul. Lula, pressionado pela oposição conservadora, intercedeu em defesa dos lucros da Petrobras, mas ao mesmo tempo reconheceu a nacionalização como expressão do direito soberano da Bolívia em legislar sobre seus próprios recursos naturais, abstendo-se de represálias. A tese explora a ambigüidade do comportamento regional do Brasil, que tenta conciliar um discurso de solidariedade em relação aos vizinhos menos desenvolvidos com uma política de expansão das empresas brasileiras e de proteção dos investimentos no exterior. O conflito em torno do gás boliviano abalou os planos brasileiros de liderança regional sul-americana e tornou mais difícil a integração energética, uma das prioridades da política externa de Lula. / The nationalization of hidrocarbons by Bolivian president Evo Morales, in May 2006, has provocated the most serious crisis in Brazilian foreign policy during Lulas first presidential term. The decision has damaged the interests of Petrobras, then the biggest corporation in Bolivia, operating in all branches of oil activities. The conflict was amplified by the interdependent relationship between the two countries through a 3.150 kilometers gasoduct, which carries almost half the natural gas consumed by Brazilian industry. By nationalization without expropriation, according to Morales formula, foreign oil corporations were allowed to stay in Bolivia, but were forced to renegociate their contracts, increasing the government take on oil and gas production. Bolivian governments decision has exposed the contradictions of Brazilian foreign policy towards its South American neighbors. Lula, under pressure from conservative opposition, has acted on behalf of Petrobras profits, but at the same time he recognized Bolivian right to set the rules on its own natural resources, and has not taken any reprisal. The thesis explores the ambiguities of Brazilian regional behavior, trying to conciliate a discourse of solidarity to lesser developed neighbors with the international expansion of Brazilian companies and investment protection abroad. The conflict about Bolivian gas has shattered Brazilian plans for regional leadership and turned more difficult energy regional integration, one of the priorities of Lulas foreign policy.
514

Interface gr?fica para redu??o de espectros ?pticos

Silva, Alberlan Lopes 16 March 2016 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-09-15T21:10:44Z No. of bitstreams: 1 dissertacao1 - F.pdf: 19663712 bytes, checksum: b4d07b5a7a0e8418855eb7151fddc47c (MD5) / Made available in DSpace on 2016-09-15T21:10:44Z (GMT). No. of bitstreams: 1 dissertacao1 - F.pdf: 19663712 bytes, checksum: b4d07b5a7a0e8418855eb7151fddc47c (MD5) Previous issue date: 2016-03-16 / This work shows the development of a graphical interface to reduce spectroscopic observations of peculiar galaxies present in the Catalogue of Southern Peculiar Galaxies and Associations (Arp and Madore 1987). The data have been observed with the Cassegrain spectrograph installed at the 1.6-m telescope of the Observat?rio do Pico dos Dias, Brazil/Laborat?rio Nacional de Astrof?sica ? Minist?rio da Ci?ncia Tecnologia e Inova??o (OOD/LNA-MCTI). The interface is called "PyOPD-Cass". In this project, the tasks present in IRAF package are sequenced together in order to produce calibrated data in flux and wavelength. Thus, the methodology used to reduce spectral data allows the user to quickly and easily insert all the necessary parameters for the spectral reduction process. The material developed in this work, within the concept of "pipeline", has the advantage of minimizing the time in the spectral reduction. As application of the computational process, we show only the spectral reduction to a selected set of 73 peculiar galaxies with emission lines observed over the long-term project carried out in OPD/LNA-MCTI ("Spectroscopic Study of Peculiar Galaxies and associations", OP2012A-009). The scientific results of these active galaxies will be discussed later in another study, already under development. All the development program was conducted in Python, further comprising PyRAF language and PyQt adapter as a basis for the final GUI architecture. / Este trabalho, aplicado na sub?rea de Astronomia Extragal?ctica, apresenta o desenvolvimento de uma interface gr?fica de redu??o de dados espectrais no ?ptico para Gal?xias Peculiares e Associa??es do Cat?logo de Arp e Madore (?A Catalogue of Southern Peculiar Galaxies and Associations?, 1987), que vem sendo observadas com o espectr?grafo Cassegrain instalado no foco f/10 do telesc?pio de 1,60m do OPD/LNA-MCTI (Observat?rio do Pico dos Dias/Laborat?rio Nacional de Astrof?sica ? Minist?rio da Ci?ncia Tecnologia e Inova??o). Denominamos a mesma neste trabalho de ?PyOPD-Cass?. Neste projeto de Computa??o Aplicada, as tarefas de redu??o de dados presentes no IRAF ser?o sequenciadas e agrupadas afim de produzir dados finais calibrados em fluxo e comprimento de onda. Dessa forma, constru?mos uma metodologia otimizada para a redu??o dos dados espectrais, a qual permitir? ao usu?rio a inser??o de maneira f?cil e r?pidade todos os par?metros necess?rios para o processo de redu??o espectral. O material desenvolvido neste trabalho, dentro do conceito de "pipeline", possui a grande vantagem de minimizar o tempo de redu??o espectral em rela??o ao processo empregado atualmente. Como aplica??o do processo computacional desenvolvido neste trabalho, ser? mostrada apenas a redu??oespectral para um conjunto selecionado de 73 gal?xias peculiarescom linhas de emiss?o observadas ao longo do projeto de longo prazo realizado no OPD/LNA-MCTI (?Estudo Espectrosc?pico de Gal?xias Peculiares e Associa??es?, OP2012A-009), de autoria do orientador deste trabalho dissertativo. Todo desenvolvimento de programa??o foi realizado no ambiente Python, integrando ainda a linguagem PyRAF e o adaptador de linguagem PyQT, como base para a arquitetura final da interface gr?fica.
515

A Robust Synthetic Basis Feature Descriptor Implementation and Applications Pertaining to Visual Odometry, Object Detection, and Image Stitching

Raven, Lindsey Ann 05 December 2017 (has links)
Feature detection and matching is an important step in many object tracking and detection algorithms. This paper discusses methods to improve upon previous work on the SYnthetic BAsis feature descriptor (SYBA) algorithm, which describes and compares image features in an efficient and discreet manner. SYBA utilizes synthetic basis images overlaid on a feature region of interest (FRI) to generate binary numbers that uniquely describe the feature contained within the FRI. These binary numbers are then used to compare against feature values in subsequent images for matching. However, in a non-ideal environment the accuracy of the feature matching suffers due to variations in image scale, and rotation. This paper introduces a new version of SYBA which processes FRI’s such that the descriptions developed by SYBA are rotation and scale invariant. To demonstrate the improvements of this robust implementation of SYBA called rSYBA, included in this paper are applications that have to cope with high amounts of image variation. The first detects objects along an oil pipeline by transforming and comparing frame-by-frame two surveillance videos recorded at two different times. The second shows camera pose plotting for a ground based vehicle using monocular visual odometry. The third generates panoramic images through image stitching and image transforms. All applications contain large amounts of image variation between image frames and therefore require a significant amount of correct feature matches to generate acceptable results.
516

Studie odkanalizování vybrané obce / The study of sewerage in selected municipalities

Kolář, Tomáš January 2018 (has links)
The subject of this diploma thesis is a study of two variants of sewer network of Cetechovice. Variant solutions include the use of existing segments supplemented by new gravitational or pressure sections. The proposed variant solutions are then economically assessed.
517

Výpočet tlakových ztrát spalinových kanálů s využitím matematického modelování / Calculation of pressure losses of flue gas ducts using mathematical modeling

Suchý, Václav January 2018 (has links)
This diploma thesis deals with the calculation of pressure losses in the flue gas ducts. First part of this work describes properties of flue gas and flow dynamics. Part of the theoretical analysis was detailed study of pipeline elements with emphasis on the reasons for the existence of pressure loss in the flow, calculations of the resistance coefficients and possible methods of reducing the losses. In the practical part, a model of the pressure loss calculation of the existing flue gas line installed in the incineration plant was created. At the end of the thesis a proposal for optimization of this route was made with emphasis on the reduction of the overall pressure loss. By optimization the pressure drop of the specified route was reduced from 3581 Pa to 2647 Pa, i.e by 26% and the required power input of the fan was reduced from 225 kW to 166,5 kW.
518

Studie variant odkanalizování obce Kamenný Malíkov / The study alternatives village sewer system Kamenný Malíkov

Rőssová, Markéta January 2019 (has links)
The diploma thesis is focused on the possibilities of drainage of waste water and its subsequent liquidation in the village of Kamenný Malíkov. The aim of this diploma thesis is the elaboration of variant solutions for drainage of Kamenný Malíkov. Furthermore, the proposal for wastewater treatment, the economic comparison of variants and the recommendation of the unsuitable variant. The diploma thesis deals with the proposal of predominantly gravitational way of drainage of waste water in combination with the pressure, due to incline terrain in the village. Each eventuality has wastewater treatment method designed.
519

Užití moderní softwarové podpory v projekční praxi procesního inženýra / Using of modern software support in the projection practice of process engineer

Zajíc, Jonáš January 2019 (has links)
The presented MSc. thesis is focused on the introduction and application of PDMS software in the process piping designing area. The introduction to the employing of the PDMS software is elaborated in the first part of the thesis as practical user manual of this software followed by the benefits of this software as a recognized supportive design program are consequently illustrated on partial solved cases from common design practice. The particular benefit of deploying PDMS in design practice is demonstrated in the thesis by economic evaluation of two selected solved industrial projection cases where design optimization of process piping system is solved with the support of this software system. Introduction of new ones broadening possibilities and current trends in the supportive design software systems, specifically using the scanner and supporting Everything3D are also presented as part of the thesis on a concrete example of the reconstruction of the boiler room.
520

Nová koncepce velkoplošných závlahových systémů / New concept of large-area irrigation systems

Pírková, Marcela January 2021 (has links)
This diploma thesis is focused on a large-scale irrigation embedded in the urban landscape. The main goal is to find a new concept of the large-scale irrigation system using a minimum of added electrical energy. The system is aimed at rainwater harvesting and distribution in populated areas. Part of the work is the analysis of the zoning plan of the selected locality, the design of the entire system from the accumulation of collected water to the distribution of watering to the root zone of plants. In the practical part, the proposed distribution network is calculated according to the current known equations, and the calculation is finished with the choice of a suitable diameter of the pipeline network. In addition, the work suggests possible sites for new planting of plants.

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