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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.
201

Podzemní garáže v Brně / The underground garage in Brno-City

Nováková, Zuzana January 2012 (has links)
The thesis focuses on the design of the underground garage in the centre of Brno under the Petrov hill. The main target of the thesis is to design spatial arrangement of the underground space and its feasibility study. In the following parts the design of the structural solution and its check calculation is carried out.
202

Zásady pro provádění řížených protlaků pod komunikacemi / Principles for the implementation of controlled pressures under roads

Komoň, Richard Unknown Date (has links)
Goal of the diploma thesis is to explain what does the term of controlled horizontal drilling mean and where it can be performed. Furthermore, it wants to show what to pay attention to during designing as well as during the actual pilot drill. Additionally, to show that pilot drill cannot be performed based on the project in all scenarios. Theoretical part of the thesis explains how the technology works and which auxiliaries are necessary to successfully perform controlled pressure. This technology is explained step by step in the practical part of the thesis to show how to proceed during the realization of controlled pressure.
203

Påldrivning: Jämförelse mellan luft- och vattendriven borrning : En utredning av jämförelser avseende slitage, logistik och driftkostnader

Bengtsson, Andreas, Bodin, Pierre January 2022 (has links)
Skanska Grundläggning in Region Special wishes to gain an increased understanding of the extent to which it differs in the wear of percussion hammers and pilot drill crowns, depending on which driving medium is used in down-the-hole drilling, as well as logistical and economic aspects depending on the chosen method. Down-the-hole drilling means that the hammer works down in the borehole and forms one of the components at the far end of the drill string together with a drill bit. The blow of the hammer is created by air or water at high pressure. The piling method that is examined is drilled steel pipe piles, which means that a steel pipe pile is driven into the ground in step with the hammer and the drill bit's advancement. Once the desired depth has been reached, the drill string with the drill bit is pulled out of the casing and then the steel pipe pile is filled with concrete. The study aims to examine the products' lifespans and repair intervals from several different perspectives and set them against reality, as well as what the different methods have for differences regarding logistics and establishment. This is to create a basis for future decisions on the most suitable method of down-the-hole drilling. The beginning of the study consisted of qualitative preliminary interviews to identify and create a problem formulation that was dealt with via a literature study, five semi-structured interviews, eleven questionnaires, internal data from drilling protocols and purchasing. The result shows that there is some difference in wear in the hammer depending on whether it is an air or water powered system, the wear appears in different places and can have an impact on the life of the hammer. The wear that occurs most frequently on drill bit is grinding on the buttons. Geotechnical differences for various projects are a significant factor in the service life of the equipment. An air hammer requires that the air constantly being mixed with lubricating oil and that an air compressor consumes more diesel compared to a high-pressure pump for the equivalent water hammer. The handling of water that is flushed out of the borehole is considered a concern. To reduce wear on water hammers and thus fewer replacements and more repairs, a drill bit intended for water powered down-the-hole hammer should be used. DTH-drilling with an air hammer is considered an industry standard and a certain skepticism towards a water powered system may indicate inexperience. / Skanska Grundläggning inom Region Special önskar att få en ökad förståelse hur vida det skiljer sig vid slitage av hammare och pilotborrkrona beroende på vilket drivande medium som nyttjas vid sänkhammarborrning, samt logistiska och ekonomiska aspekter beroende på vald metod. Sänkhammarborrning innebär att hammaren arbetar nere i borrhålet och utgör en av komponenterna längst ut på borrsträngen tillsammans med en borrkrona. Hammarens slag skapas av luft eller vatten i högt tryck. Pålningsmetoden som undersöks är borrade stålrörspålar, det betyder att ett foderrör drivs ned i marken i takt med hammaren och borrkronans framfart. Väl när önskat djup uppnåtts lyfts borrsträngen med hammaren och piloten upp ur foderröret för att sedan fyllas upp med betong. Studien syftar till att undersöka produkternas livslängder och reparationsintervall från flera olika perspektiv och ställa dem emot verkligheten, samt vad dem olika metoderna har för olikheter kring logistik och etablering. Detta är för att skapa underlag för framtida beslut om mest lämplig metod av sänkhammarborrning. Studiens begynnelse bestod av kvalitativa förintervjuer för att identifiera och skapa en problemformulering som avhandlades via en litteraturstudie, fem semistrukturerade intervjuer, elva frågeformulär, interna data från borrningsprotokoll och inköp. Resultatet visar att det förekommer viss skillnad i slitage i hammaren beroende på om det är en luft- eller vattenanläggning, slitaget visar sig på olika ställen och kan ha betydelse för hammarens livslängd. Det slitage som uppträder mest frekvent på piloter är nedslipning av stift. Geotekniska egenskaper för olika projekt utgör en betydande faktor för utrustningens livslängd. En lufthammare är i behov av att luften konstant beblandas smörjolja och att en luftkompressor förbrukar mer diesel jämfört med en högtryckspump för motsvarande vattenhammare. Efterhanteringen av vatten som spolas upp anses vara ett bekymmer. För att minska slitage på vattenhammare och därmed färre byten och mer reparationer bör en pilotborrkrona avsedd för vattendriven sänkhammarborrning nyttjas. Sänkhammarborrning med lufthammare anses som branschstandard och en viss skepticism mot en vattendriven anläggning kan tyda på oerfarenhet.
204

Hyperspectral drill-core scanning in geometallurgy

Tusa, Laura 01 June 2023 (has links)
Driven by the need to use mineral resources more sustainably, and the increasing complexity of ore deposits still available for commercial exploitation, the acquisition of quantitative data on mineralogy and microfabric has become an important need in the execution of exploration and geometallurgical test programmes. Hyperspectral drill-core scanning has the potential to be an excellent tool for providing such data in a fast, non- destructive and reproducible manner. However, there is a distinct lack of integrated methodologies to make use of these data through-out the exploration and mining chain. This thesis presents a first framework for the use of hyperspectral drill-core scanning as a pillar in exploration and geometallurgical programmes. This is achieved through the development of methods for (1) the automated mapping of alteration minerals and assemblages, (2) the extraction of quantitative mineralogical data with high resolution over the drill-cores, (3) the evaluation of the suitability of hyperspectral sensors for the pre-concentration of ores and (4) the use of hyperspectral drill- core imaging as a basis for geometallurgical domain definition and the population of these domains with mineralogical and microfabric information.:Introduction Materials and methods Assessment of alteration mineralogy and vein types using hyperspectral data Hyperspectral imaging for quasi-quantitative mineralogical studies Hyperspectral sensors for ore beneficiation 3D integration of hyperspectral data for deposit modelling Concluding remarks References
205

CORROSION-FATIGUE TESTING ON STEEL GRADES WITH DIFFERENT HEAT AND SURFACE TREATMENTS USED IN ROCK-DRILLING APPLICATIONS

Béjar, Luis Miguel January 2016 (has links)
Corrosion fatigue is a common failure mechanism in rock drilling components and many othermechanical parts subjected to cyclic loads in corrosive environments. A crucial part in the design ofsuch components resides in the selection of the right materials for the application, which ideallyinvolves testing and comparison of their performance under working conditions. The present work was performed with the purpose of designing a corrosion-fatigue testing methodthat would allow the designer to compare the performance of different materials exposed to corrosionfatigue, permitting also the comparison with results from dry fatigue testing. The method was designedfor rotating-bending machines. Two different steel grades were used during the work, one throughhardened and one case hardened. The effect of these heat treatments and of shot peening overcorrosion-fatigue behaviour were studied using the proposed method. It was proven that the testing speed has a strong impact on the fatigue life of steel. It was found that,at a fixed stress level, the case hardened and shot peened steel reached 3X10^6 cycles at 2300 rpm,while it failed at only 5X10^5 cycles with a testing speed of 500 rpm. A large beneficial influence of theshot peening was demonstrated. It was also observed that, at fixed testing speed, the shot peening onthe through hardened steel can increase its fatigue strength from 190 MPa to 600 MPa under corrosionfatigue. Many cracks were found at the surface of the shot peened parts, which are arrested near thesurface by the compressive stress layer from the shot peening. It was also found that, for the non-shotpeened parts, case hardening had a slightly higher corrosion-fatigue strength than the throughhardened. This might be a result of the compressive stresses from carburization, or due to the highercore toughness of this steel grade.
206

Modeling and Simulation for Power Loss Estimation in Electrified Drill Rigs

Chit, Ali January 2024 (has links)
This master's thesis aims to establish a foundation for model-based engineering of drill rigs through the development, evaluation, and utilization of simulation models. Specifically, the project focused on creating a simulation model of the hydraulic tramming system in the SmartRoc D65 surface drill rig. The uncalibrated model was validated against physical tests conducted on the SmartRoc T35 drill rig, and the results provided accurate predictions with some room for improvement. The model sets a basis for identifying power losses and future potential optimization through electrification. A modeling methodology was developed to aid in the development of other simulation models representing a physical system. The thesis highlights the strengths and limitations of a quasi-static model when applied to dynamic systems. The findings suggest areas for future improvement and underscore the importance of continuous model refinement to enhance calculation accuracy.
207

[pt] ANÁLISE DA DINÂMICA NÃO LINEAR DE UMA BANCADA EXPERIMENTAL DE UMA COLUNA DE PERFURAÇÃO COM VIBRAÇÃO TORCIONAL INDUZIDA POR ATRITO / [en] NONLINEAR DYNAMIC ANALYSIS OF DRY FRICTION-INDUCED TORSIONAL VIBRATION IN A DRILL-STRING EXPERIMENTAL SET-UP

BRUNO CESAR CAYRES ANDRADE 01 November 2018 (has links)
[pt] Os últimos leilões do pré-sal para exploração e produção de petróleo e gás no Brasil indicam que as operações de perfuração se tornarão mais intensas nos próximos anos. O processo de perfuração rotativo é amplamente utilizado para alcançar os reservatórios de petróleo e devido à relação diâmetro/comprimento do sistema de perfuração, o modo de vibração torcional está presente em quase todos os processos de perfuração, podendo chegar a um estado crítico indesejável: o fenômeno de stick-slip. Com o intuito de abordar este problema, o modo torcional é isolado e o stick-slip é observado em uma coluna de perfuração em escala reduzida completamente instrumentada. Durante o stick-slip, outro torque pode ser aplicado em uma posição intermediária da bancada de teste. O modelo matemático de parâmetros concentrados é obtido e o modelo é comparado com dados experimentais com o propósito de verificar se o modelo matemático representa o aparato experimental. Uma análise de estabilidade é feita usando o modelo validado com o objetivo de identificar soluções estáveis do sistema. Com isso, observou-se que existe uma faixa do parâmetro de bifurcação na qual soluções de equilíbrio e periódicas estáveis coexistem. Para uma dada situação de stick-slip na faixa de biestabilidade, duas estratégias de mitigação de vibração torcional foram consideradas e consistiram em impor perturbações no sistema por meio do torque na posição intermediária da bancada de teste: (i) torques aplicados apenas contra a direção de movimento do sistema, e (ii) torques aplicados em ambas as direções. As estratégias foram testadas numericamente e apresentaram eficiência de tal modo que o stick-slip foi completamente mitigado: as energias do sistema e o trabalho gerado pelo torque intermediário aplicado foram comparados com o propósito de avaliar a factibilidade e razoabilidade da estratégia. Experimentalmente, o sistema continuou a oscilar, porém apresentou uma significante redução na fase de stick mesmo com limitações de aplicações de torque. / [en] The latter round bids of the pre-salt for exploration and production of oil and natural gas in Brazil indicate the drilling operations will become more intense in coming years. The rotational drilling process is largely used to reach the oil reservoirs and because of diameter-to-length ratio of the drilling system, torsional vibration mode is present in most all drilling processes and may reach an undesired severe stage: the stick-slip phenomenon. In order to address this problem, the torsional vibration mode is isolated and the stick-slip is observed in a fully instrumented drill-string experimental set-up in this work. During this phenomenon, another torque may be applied on an intermediate position of the test bench. The lumped parameter mathematical model is obtained and it is compared to experimental data to validate whether the mathematical model represents the experimental apparatus. A stability analysis is performed using the validated mathematical model in order to identify stable solutions of the system. Therewith, one observed that there is a range of the bifurcation parameter in which stable equilibrium and periodic solutions may coexist. For a given stick-slip situation in bi-stability range, two mitigation strategies of torsional vibration were considered which consisted of imposing perturbations in the system via torques on the intermediate position of the test bench: (i) torques applied only against the direction of motion of the system, and (ii) torques applied in both directions. The strategies were tested numerically and presented eficiency so that the stickslip was completely mitigated: the energies of the system and the work created by the intermediate torque were compared in order evaluate the feasibility and reasonableness of the strategy. Experimentally, the system continued to oscillate, however it presented a significant reduction of stick phase even with limitations of torque applications.
208

Modélisation et optimisation énergétique des organes d'un semoir pneumatique / Modeling and energy optimization of the operative parts of an air assisted drill

Yatskul, Andrii 04 May 2016 (has links)
Dans le contexte du développement d’une agriculture durable, il est nécessaire d’optimiser le coût énergétique des opérations agricoles tout en garantissant des temps de travaux courts ainsi que la qualité des opérations réalisées. Cette question concerne en particulier l’opération du semis qui est déterminante pour la qualité de la future récolte. Les semoirs de grande capacité et à haute productivité conçus aujourd’hui se doivent d’être compatibles avec cet ensemble de contraintes. L’enjeu essentiel de cette thèse est donc d’élaborer une méthodologie innovante et utilisant des outils de modélisation dans le but de réduire la consommation énergétique des matériels de semis. En suivant cette logique, nous avons étudié quatre aspects clef de la conception des semoirs pneumatiques : la manœuvrabilité des semoirs poly-articulés, l’établissement des conditions du transport pneumatique des semences et des engrais, l’optimisation des systèmes de répartition des semences ou des engrais, et enfin les aspects énergétiques du mode d’introduction des semences dans le circuit pneumatique. Chaque modélisation a été précédée par une phase expérimentale de détermination des phénomènes majoritaires influençant le processus étudié. Ensuite une modélisation du processus étudié, basée sur la simulation des effets du phénomène majoritaire identifié a pu être mise en œuvre et des conclusions, appuyées par des essais expérimentaux, proposées quant à la conception des semoirs pneumatiques. L’étude de la manœuvrabilité des ensembles poly articulés a démontré qu’il était possible de proposer et de tester un modèle explicatif de prédiction de trajectoires adapté aux engins agricoles. Cette approche ouvre la voie à l’optimisation et à de nouvelles méthodes d’automatisation de manœuvres complexes, notamment des demi-tours en bout de champ. Il est par ailleurs possible de démontrer qu’une trémie en position arrière permet de réaligner plus rapidement la barre de semis après une manœuvre. L’étude des conditions du transport pneumatique a montré notamment que l’établissement de conditions de transport correctes au niveau des sorties de la tête de distribution conditionne l’ensemble de la conception du circuit de distribution de la matière. L’étude des systèmes de répartition des semences a permis d’expliquer l’origine des principaux défauts de répartition observés et notamment l’importance de l’adéquation entre le coude et la conduite verticale qui précède la tête de répartition des semences. Ces résultats ont ouvert la voie à l’étude de la mise en place de systèmes d’anticipation et de correction de ces défauts. Enfin l’étude comparée de deux systèmes d’introduction de la matière dans un circuit pneumatique a montré que du point de vue énergétique les systèmes pressurisés sont plus intéressants que les systèmes injecteurs. / In the context of sustainable farming, the optimization of the energy costs of agricultural operations allows shorter working times and high quality of the agricultural operations. This question relates particularly to the seeding. This operation one is decisive for the quality of the future harvest. The modern high capacity seed drills must be compatible with all the constraints. The main goal of this PhD thesis is thus to develop an innovative methodology, integrating the modeling tools, in order to reduce the energy consumption of the heavy seeding equipment. Thus, we explored four key aspects concerning air seed drill design: maneuverability of poly-articulated seed drills; establishment of the pneumatic conveying conditions of seeds and fertilizers; seed distribution accuracy optimization, and finally the energy aspects of the air stream loading systems. Each modeling was preceded by a preliminary experimental phase, defying the majority phenomena influencing the studied process. The modeling of the studied process and the conclusions (supported by experimental trials) have been proposed for the design of air seed drills. The study of maneuverability of poly-articulated agricultural machines showed that it was possible to get and test an explanatory model of trajectory prediction adapted for agricultural machines. This approach opens the way for optimization and automation of complex operations, including U-turns on headlands. We showed that a towed behind storage hopper (air-cart) allows faster realignment of the coulter bar after maneuvers. The study of pneumatic conveying conditions showed that the establishment of the correct conveying conditions in the outlets after the dispensing head defines the entire design of the distribution system. The study of seed distribution systems explains that the origin of the low distribution accuracy is caused in particular by the elbow and the vertical pipe before the dispensing head. These results open the way for the development of anticipation systems and correction of these defects. Finally the comparative study of two air-stream loading systems has showed that from the energy point of view the pressurized systems are more interesting than the injectors systems. / В рамках концепции устойчивого развития, необходимо учитывать энергетический аспект, сохраняя при этом эффективность использования рабочего времени и качества выполнения сельскохозяйственных операций. Особенно, это касается операции посева, определяющей в наибольшей степени будущий урожай. Современные широкозахватные зерновые сеялки и посевные комплексы вписываются в рамки устойчивого сельского хозяйства. Главной целью данной диссертации является разработка действенной методики проектирования пневматических сеялок, применяя методы моделирования и оптимизации, с целью уменьшения энергопотребления. Таким образом, мы использовали причинно-следственный подход для энергетической оптимизации четырех определяющих параметров: маневренность многозвеньевых посевных машин, обоснования необходимых условий пневмотранспорта, оптимизация распределения посевного материала, и ввода материала в магистральный трубопровод. В дополнение, снижение энергопотребления не должно сказываться на качестве выполнения технологического процесса посева. Моделирование каждого процесса, является следствием длительной экспериментальной фазы, посвященной определению наиболее значимых факторов, для каждого отдельного явления. В результате моделирований, симуляций и анализа, были составлены практические рекомендации, для конструкторов пневматических сеялок. Изучение маневренных характеристик многозвеньевых агрегатов позволило предложить и испытать физическую модель, позволяющую предопределить траекторию движение каждого звена машинно-тракторного агрегата. Такой подход позволяет автоматизировать выполнение наиболее сложных маневров (например, разворотов в конце гона). Кроме всего было показано, что заднеприцепные бункера позволяют более быстрое выравнивание агрегата после разворота. Изучение условий пневмотранспорта, позволило установить оптимальные, с точки зрения энергосбережения, параметры пневмотранспорта на выходе из распределительной головки, что послужило исходными данными для расчета характеристик пневмотранспорта в целом. Исследование процесса распределения семян в распределительной головке вертикального типа, позволило определить причины неравномерного распределения семян между выходными трубопроводами, в частности влияние отвода и вертикального трубопровода. На основании полученных данных, было предложена система устройств, позволяющих избежать возникновения завалов в системе, при минимальных энергопотерях. Сравнительные исследования двух систем ввода материала в магистральный трубопровод, позволили заключить, что питатели с наддувом являются менее энергоемкими по сравнению с питателями эжекторного типа.
209

Impact assessment of the environmental protection policies in the upstream oil industry in Nigeria / A.M. Bayagbon.

Bayagbon, Anthony Mamurhomu January 2011 (has links)
The need for energy and the associated economic benefits from the oil and gas deposits found mainly in the Niger Delta region of Nigeria necessitated the exploration and exploitation activities being carried out by the oil and gas Companies. However, these exploration and exploitation activities due to their unpredictable nature have a huge potential for environmental pollution as been experienced in the form of oil spills, gas flaring, irresponsible disposal of waste and several other activities that have resulted in the environmental degradation of the Niger Delta region. In the light of these, the Federal Government of Nigeria having experienced the consequences of pollution of the environment during the Koko Toxic Waste Dump incident in the then Bendel State in 1987 established a regulatory body tasked with the responsibility of harmonizing the economic interest from the oil and gas exploration and exploitation activities with the sustainability of the natural environment by developing well structured and articulated policies aimed at guiding the operations of the oil and gas operators, track their compliance and administer appropriate punitive measures for non compliance. However, this research work which is aimed at evaluating the impact of the environmental protection policies in upstream oil and gas activities in the Niger Delta region, involved the use of questionnaires and interviews. These questionnaires were completed by the management and staff of three major oil and gas companies operating within the area, the Department of Petroleum Resources and members of the Host communities. The interview was carried out to provide relevant feedback on their assessment of the impact made by the environmental protection policies on the upstream oil and gas activities in their operational areas/host communities. The study however concluded that “Although there is a regulatory body tasked with the responsibility to develop, implement and track compliance of the environmental protection policies in the upstream oil industry, the body is ineffective and as such the impact of the environmental protection policies is inadequate. Appropriate informed recommendations on the improvement strategies to the identified gaps that resulted in the unfavorable conditions were also provided. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011
210

Impact assessment of the environmental protection policies in the upstream oil industry in Nigeria / A.M. Bayagbon.

Bayagbon, Anthony Mamurhomu January 2011 (has links)
The need for energy and the associated economic benefits from the oil and gas deposits found mainly in the Niger Delta region of Nigeria necessitated the exploration and exploitation activities being carried out by the oil and gas Companies. However, these exploration and exploitation activities due to their unpredictable nature have a huge potential for environmental pollution as been experienced in the form of oil spills, gas flaring, irresponsible disposal of waste and several other activities that have resulted in the environmental degradation of the Niger Delta region. In the light of these, the Federal Government of Nigeria having experienced the consequences of pollution of the environment during the Koko Toxic Waste Dump incident in the then Bendel State in 1987 established a regulatory body tasked with the responsibility of harmonizing the economic interest from the oil and gas exploration and exploitation activities with the sustainability of the natural environment by developing well structured and articulated policies aimed at guiding the operations of the oil and gas operators, track their compliance and administer appropriate punitive measures for non compliance. However, this research work which is aimed at evaluating the impact of the environmental protection policies in upstream oil and gas activities in the Niger Delta region, involved the use of questionnaires and interviews. These questionnaires were completed by the management and staff of three major oil and gas companies operating within the area, the Department of Petroleum Resources and members of the Host communities. The interview was carried out to provide relevant feedback on their assessment of the impact made by the environmental protection policies on the upstream oil and gas activities in their operational areas/host communities. The study however concluded that “Although there is a regulatory body tasked with the responsibility to develop, implement and track compliance of the environmental protection policies in the upstream oil industry, the body is ineffective and as such the impact of the environmental protection policies is inadequate. Appropriate informed recommendations on the improvement strategies to the identified gaps that resulted in the unfavorable conditions were also provided. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011

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