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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

An Improved Model for Prediction of PM10 from Surface Mining Operations

Reed, William Randolph 23 April 2003 (has links)
Air quality permits are required for the construction of all new surface mining operations. An air quality permit requires a surface mining operation to estimate the type and amount of pollutants the facility will produce. During surface mining the most common pollutant is particulate matter having an aerodynamic diameter less than 10 microns (PM10). The Industrial Source Complex (ISC3) model, created by the United States Environmental Protection Agency (U.S. EPA), is a model used for predicting dispersion of pollutants from industrial facilities, including surface mines and quarries. The use of this model is required when applying for a surface mining permit. However, the U.S. EPA and mining companies have repeatedly demonstrated that this model over-predicts the amount of PM10 dispersed by surface mining facilities, resulting in denied air quality permits. Past research has shown that haul trucks create the majority (80-90%) of PM10 emissions from surface mining operations. Therefore, this research concentrated on improving the ISC3 model by focusing on modeling PM10 emissions from mobile sources, specifically haul trucks at surface mining operations. Research into the ISC3 model showed that its original intended use was for facilities that emit pollutants via smoke stacks. The method used to improve the ISC3 model consisted of applying the dispersion equation used by the ISC3 model in a manner more representative of a moving haul truck. A new model called the Dynamic Component Program was developed to allow modeling of dust dispersion from haul trucks. To validate the Dynamic Component Program, field experiments were designed and conducted. These experiments measured PM10 from haul trucks at two different surface mining operations. The resulting analysis of the Dynamic Component Program, ISC3 model, and the actual field study results showed that the Dynamic Component Program was a 77% improvement over the ISC3 model overall. / Ph. D.
2

Collision Avoidance Systems for Mine Haul Trucks and Unambiguous Dynamic Real Time Single Object Detection

Glynn, Patrick Joseph, n/a January 2005 (has links)
A suite of new collision avoidance systems (CAS) is presented for use in heavy vehicles whose structure and size necessarily impede driver visibility is introduced. The main goal of the project is to determine the appropriate use of each of the commercially available technologies and, where possible, produce a low cost variant suitable for use in proximity detection on large mining industry haul trucks. CAS variants produced were subjected to a field demonstration and, linked to the output from the earlier CAS 1 project, (a production high-definition in-cabin video monitor and r/f tagging system). The CAS 2 system used low cost Doppler continuous wave radar antennae coupled to the CAS 1 monitor to indicate the presence of an object moving at any speed above 3 Km/h relative to the antennae. The novelty of the CAS 3 system lies in the design of 3 interconnected, modules. The modules are 8 radar antennae (as used in CAS 2) modules located on the truck, software to interface with the end user (i.e. the drivers of the trucks) and a display unit. Modularisation enables the components to be independently tested, evaluated and replaced when in use. The radar antennae modules and the system as a whole are described together with the empirical tests conducted and results obtained. The tests, drawing on Monte-Carlo simulation techniques, demonstrate both the 'correctness' of the implementations and the effectiveness of the system. The results of the testing of the final prototype unit were highly successful both as a computer simulation level and in practical tests on light vehicles. A number of points, (as a consequence of the field test), are reviewed and their application to future projects discussed.
3

Estudo da sobrecarga dinamica em caminões por meio de medições diretamente no veiculo / Study of the dynamic overload on trucks by direct measurements in the vehicle

Antonio, Sergio Francisco Dela 12 August 2018 (has links)
Orientador: Auteliano Antunes dos Santos Jr / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T19:38:01Z (GMT). No. of bitstreams: 1 Antonio_SergioFranciscoDela_M.pdf: 2654431 bytes, checksum: a9d019fe7f3a17bc52fb361d8113f727 (MD5) Previous issue date: 2005 / Resumo: As cargas dinâmicas que ocorrem em veículos de carga quando estes estão em movimento, são fortemente responsáveis pela deterioração precoce do piso asfáltico das rodovias e logradouros no Brasil. Também são umas das principais responsáveis pelo desgaste excessivo e prematuro dos componentes do veículo. Estes dois fatores fazem com que os custos de transporte rodoviário no Brasil, de mercadorias e bens, fiquem mais elevados. O objetivo deste trabalho é avaliar uma metodologia para medir as cargas dinâmicas que ocorrem em veículos de carga. Na metodologia proposta, utilizou-se a própria suspensão do veículo como parte do sistema de medição, no caso, veículos com suspensão com feixes de molas. O sistema de medida das cargas dinâmicas é composto pelos feixes de molas e um transdutor de deslocamento. Gerou-se a curva de resposta do feixe de molas com relação aos deslocamentos ocorridos através da aplicação das cargas. Após os estudos preliminares, implantou-se este sistema na suspensão dianteira de um veículo de carga de porte médio. Estimaram-se as cargas dinâmicas em várias condições de piso com o veículo carregado, a partir dos deslocamentos medidos. Os resultados mostram que o sistema funcionou satisfatoriamente, e foi possível quantificar os níveis de cargas dinâmicas ocorridas em casos mais críticos. O maior nível encontrado foi de 33,9% acima da carga estática no lado esquerdo da suspensão dianteira, no trecho com lombadas. / Abstract: The dynamical loads and forces occurring in cargo vehicles under movement are among the major causes of the early deterioration on highway and road pavement in Brazil. These dynamical loads are also responsible for the premature and excessive wear on several vehicle components. These two factors combined are among the main reasons why road transportation costs are so expensive in Brazil. The objective of this work is to suggest and evaluate a methodology for measuring the dynamical loads and forces on moving cargo vehicles. This methodology utilizes the suspension system of the vehicle itself as part of the measurement system. In the experimental part of this study a force measuring system was conceived using the leaf spring assembly of the vehicle suspension combined with a simple displacement transducer strategically installed in the vehicle suspension. This force measuring system was installed in a mid-range cargo truck. The characteristic curve of the suspension leaf spring set was determined by the application of static loads onto the vehicle. After calibration and fine adjustments of the system, several experimental runs were performed in the loaded vehicle, measuring the dynamic loads in several pavement types and traffic conditions. The results showed that the system worked satisfactorily, and it was possible to determine the dynamic loads occurred on all experimental runs. The greatest dynamic load found in the field was 33,9 % above the static load on the left front suspension. / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica
4

Haul road defect identification and condition assessment using measured truck response

Hugo, Daniel 16 July 2008 (has links)
Mine haul road maintenance is traditionally done at scheduled intervals or after regular inspection. Both these methods can lead to unwarranted expenditure, either through over-maintaining the road, or failure to recognise significant deterioration, resulting in an increase in vehicle operating costs. Predictive maintenance management models for unpaved roads have been developed in recent years. These methods work well in a trivial environment where variables such as traffic volume can be predicted. However, many mining systems are too complex for such models to be effective. This work investigates the possibility of using haul truck response to aid haul road maintenance management. The approach adopted for the study was twofold: Firstly, can truck response data be used to recognise specific road defects, in terms of location, type and size? This is important since different defect types require different road maintenance strategies. Secondly, can road roughness be measured on a qualitative basis? With the emphasis on road defect reconstruction, a mathematical modelling approach was adopted. The truck was characterised in terms of its suspension and tyre properties. Dynamic truck response data was acquired during field measurements in which the vehicle was driven over defects of known dimensions. With these data sets available, mathematical modelling and simulation was possible. Quarter vehicle and seven degree of freedom vehicle models played a vital role in this work by laying a foundation in the use of haul truck response for the purpose of road defect reconstruction. A modelling methodology that is based on dynamic equilibrium of an independent front unsprung mass of the truck is proposed in which the vertical dynamic tyre force and eventually the road geometry is calculated. It is shown that defects can be reconstructed from measured truck response data with an accuracy sufficient to fulfil the requirements of defect recognition for road maintenance management purposes. Secondly, a preliminary investigation into the qualitative assessment of road condition via truck response measurements was conducted. The inherent response properties of the truck pertaining to road roughness measurement were studied and some correlation between measured suspension motion and road roughness measured with a high speed profilometer was found. / Dissertation (MEng (Mechanical))--University of Pretoria, 2005. / Mechanical and Aeronautical Engineering / MEng / Unrestricted

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