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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

Evaluation of an Aerobic Composting Process for the Management of Specified Risk Materials (SRM)

Zeng, Jian 24 January 2011 (has links)
In Atlantic Canada, approximately 8000 tonnes of Specific Risk Materials (SRM) is produced annually. Composting offers a means to partially treat and stabilize SRM. In this project, different types of agricultural residuals and wastes were used to compost with SRM in a pilot scale. The results were discussed based on the change in total carbon and nitrogen, pH, temperature, moisture content and electrical conductivity, which were measured at regular intervals over the study. The temperature for all treatments met the CCME pathogen control guideline. The maturity test showed that the CO2-C in all the compost was less than 1 mg/g organic matter/day. Straw and other agricultural wastes performed well in the composting SRM, other advantages includes greater availability, lower cost and more easily decomposed carbon compounds.
2

Implementation of a Novel Soft-Switching Topology for Switched Reluctance Motor Drives

Yadlapalli, Naveen 17 July 1999 (has links)
The purpose of this thesis is to design, develop, implement and test a novel soft-switching inverter topology suitable for switched reluctance motor drives. Present research being done in the field of switched reluctance motor drive inverters, including soft-switching inverters, is discussed. The novel topology is presented and the principle of operation is described in detail. The validity of the topology is verified through simulation. The various components of the system are designed and the hardware implementation is presented. Experiments carried out to verify the operation of this inverter are explained. Results are presented and comparison is made between hard switching and soft switching inverter topologies. Conclusions are drawn regarding the effectiveness of the proposed topology. / Master of Science
3

A Position Sensorless Control of Switched Reluctance Motors

Wang, Xiao Jr January 2016 (has links)
Switched reluctance motor (SRM) is an attractive candidate for many industrial and domestic applications such as electric vehicles and home appliances. Rotor position detection is of significant importance for SRM control. However, external position sensors like absolute encoders and magnetic sensors reduce the reliability of SRM drive system in hash environments and increase the cost. Therefore, position sensorless control becomes a promising technique for SRM. In this thesis, a new position sensorless control method for SRM is proposed to estimate rotor position and speed. Sliding mode observer is adopted at high speed and pulse injection method is adopted at low speed. Both of the two methods are adopted with a motion model based on the third order phase locked loop to improve the dynamic tracking performance. The analysis method of the proposed position sensorless method is also presented. Both simulation and experiment results are presented to verify the proposed sensorless control method. The simulation results show that the proposed method can precisely estimate rotor position and speed with short response time. Experimental results further demonstrate the reliability and effectiveness of the proposed positon sensorless control method. / Thesis / Master of Applied Science (MASc)
4

A dynamic circuit-based model for ferromagnetic materials

Wicks, Kenneth 05 1900 (has links)
In recent years there has been increased interest in the development of sensorless switched reluctance machine drives. The proper operation of a switched reluctance machine (SRM) requires knowledge of the position of the rotor of the machine. The inclusion of a physical position sensor compromises the inherent robustness of this type of machine. Thus, there has been a need to develop techniques to estimate the position of the rotor in SRM drives. Switched reluctance machines are able to operate over a large range in speed. A fully loaded SRM is typically designed to saturate the ferromagnetic material that comprises the stator and rotor of the machine whereas a lightly loaded machine does not. Therefore, the model of the machine should be able to handle both a large range in frequency and input excitation levels of the magnetic material in the machine. The development of a new dynamic circuit-based ferromagnetic model is described in this thesis. The investigation of the behaviour of 24 gauge M19 silicon steel led to the conclusion that, for this material, a circuit model that has static parameters is unable to accurately reproduce the behaviour of the actual material over a large range of input frequencies and excitation levels without resorting to retuning the parameters of the model. This thesis provides two new mechanisms that dynamically adjust the resistance values of the flux tubes of the model. Comparisons using a normalized vertical least-squares metric between the newly proposed dynamic model and a model that has static resistance values clearly show the improvement that is gained by using these mechanisms. A practical implementation of the new model is also given. Timing using a general purpose CPU shows that this implementation of the model will most likely be able to be used as part of a multi-phase lumped parameter model for a SRM in realtime.
5

ACTIVE FILTER FOR IMPROVING A SWITCHED RELUCTANCE MOTOR DRIVE's INPUT POWER QUALITY

Feng, Xiaohu 01 January 2005 (has links)
This thesis develops a hardware circuit implementation of an active filter for reducing a SRM drives input current ripple or equivalently to improve the SRM drives input power quality. Its an alternative to the simple inductor and capacitor in a conventional passive filter. For the same filtering capability the size of the two physical capacitors in the active filter will be much less than the size of the capacitor in a conventional filter. Also the size of the two inductors in the active filter will be much less than the size of the inductor in a conventional filter. Some of this size reduction will be consumed by the power semiconductors but their size is much smaller than the filter components being replaced. This thesis describes the design of the active filter circuit which can replace the conventional passive filter. In this thesis, feedback control is also used with the active filter to force the filter voltage to be the desired value to minimize the effects of the circuits resonances. The active filter circuit is tested experimentally with a test circuit that mimics the current ripple generated by an SRM drive system. The experimentally generated output is verified by comparing it with simulation results from a detailed SIMULINK model and a B2 spice model of the experimental system.
6

A dynamic circuit-based model for ferromagnetic materials

Wicks, Kenneth 05 1900 (has links)
In recent years there has been increased interest in the development of sensorless switched reluctance machine drives. The proper operation of a switched reluctance machine (SRM) requires knowledge of the position of the rotor of the machine. The inclusion of a physical position sensor compromises the inherent robustness of this type of machine. Thus, there has been a need to develop techniques to estimate the position of the rotor in SRM drives. Switched reluctance machines are able to operate over a large range in speed. A fully loaded SRM is typically designed to saturate the ferromagnetic material that comprises the stator and rotor of the machine whereas a lightly loaded machine does not. Therefore, the model of the machine should be able to handle both a large range in frequency and input excitation levels of the magnetic material in the machine. The development of a new dynamic circuit-based ferromagnetic model is described in this thesis. The investigation of the behaviour of 24 gauge M19 silicon steel led to the conclusion that, for this material, a circuit model that has static parameters is unable to accurately reproduce the behaviour of the actual material over a large range of input frequencies and excitation levels without resorting to retuning the parameters of the model. This thesis provides two new mechanisms that dynamically adjust the resistance values of the flux tubes of the model. Comparisons using a normalized vertical least-squares metric between the newly proposed dynamic model and a model that has static resistance values clearly show the improvement that is gained by using these mechanisms. A practical implementation of the new model is also given. Timing using a general purpose CPU shows that this implementation of the model will most likely be able to be used as part of a multi-phase lumped parameter model for a SRM in realtime.
7

Currículo e atendimento educacional especializado na Educação Infantil: possibilidades e desafios à inclusão escolar.

COTONHOTO, L. A. 27 February 2014 (has links)
Made available in DSpace on 2016-08-29T11:03:56Z (GMT). No. of bitstreams: 1 tese_7559_CURRÍCULO E ATENDIMENTO EDUCACIONAL ESPECIALIZADO NA EDUCAÇÃO INFANTIL.pdf: 1703377 bytes, checksum: 88282ad133c1c24b41bbe0704fb8a320 (MD5) Previous issue date: 2014-02-27 / Esta pesquisa teve como objetivo geral compreender a proposta/ prática curricular do Atendimento Educacional Especializado (AEE) na Sala de Recursos Multifuncionais (SRM) enquanto função complementar na educação da criança pequena com deficiência e Transtornos Globais do Desenvolvimento (TGD). Partimos das constatações de que, nas duas últimas décadas, documentos oficiais, assim como pesquisas na área, apontam a necessidade de um trabalho pedagógico inclusivo, que atenda às demandas e características dos diferentes sujeitos matriculados. Questionamos se a proposta e prática curricular complementar do AEE, por meio da SRM, têm contribuído para a inclusão da criança pequena, público alvo da educação especial, nas práticas pedagógicas da sala de aula comum? Teoricamente buscamos as contribuições da Abordagem Histórico-Cultural para compreender o desenvolvimento e aprendizagem da criança com deficiência, assim como procuramos a interlocução com os teóricos do currículo, entre os quais Sacristán. Como metodologia, utilizamos a pesquisa-ação colaborativo-crítico. O lócus da pesquisa foi um Centro de Educação Infantil, situado em Vitória/ES, com uma sala de recurso multifuncional, modelo proposto pelo Ministério da Educação (MEC). Os sujeitos participantes foram crianças de 3 a 7 anos matriculadas no Centro Municipal de Educação Infantil (CMEI) e encaminhadas para o AEE, na SRM (seis crianças surdas, sete crianças com manifestações de TGD e uma criança com Síndrome de Down); dois professores de educação especial da SRM (uma professora da área da área de Deficiência Intelectual (DI), uma professora bilíngue e um instrutor surdo); professores regentes do turno da manhã CMEI e dois pedagogos. Como perspectiva teórico-metodológica, optamos pela rede significações (Rossetti-Ferreira, 2004) que tem seus pressupostos fundamentados na teoria histórico-cultural, que compreende os processos de desenvolvimento humano como atos de significação constituídos por múltiplas interações estabelecidas social e culturalmente pelos sujeitos durante toda a vida. A organização e análise dos dados ocorreram por meio dos movimentos, cenários e atores; as práticas curriculares inclusivas na/da escola: a SRM e a sala de aula comum em seus encontros e desencontros; a preocupação com o desenvolvimento psicomotor da criança; o brincar versus a aquisição da leitura e escrita; o diálogo entre o currículo da SRM e a sala de aula comum e os encontros colaborativos com os professores de educação especial, com as pedagogas e com as professoras regentes do CMEI. Algumas considerações importantes se destacam, entre as quais: a falta de formação e desconhecimento por parte dos professores de educação especial sobre a proposta curricular da educação infantil e práticas pedagógicas descontextualizadas e fragmentadas desenvolvidas na SRM, que dificultam a ação complementar ao trabalho da classe comum. Para as professoras das salas de atividades o AEE é viável na escola de educação infantil, mas não somente na SRM, concordam que deve haver o atendimento educacional especializado no turno em que a criança esteja matriculada; que ele pode ajudar na inclusão da criança público alvo da educação especial, por meio de práticas sociais e culturais lúdicas, linguísticas e intelectuais. Concluímos que as professoras desejam um AEE dinâmico, interlocutor, que se movimente na escola como um todo.
8

A dynamic circuit-based model for ferromagnetic materials

Wicks, Kenneth 05 1900 (has links)
In recent years there has been increased interest in the development of sensorless switched reluctance machine drives. The proper operation of a switched reluctance machine (SRM) requires knowledge of the position of the rotor of the machine. The inclusion of a physical position sensor compromises the inherent robustness of this type of machine. Thus, there has been a need to develop techniques to estimate the position of the rotor in SRM drives. Switched reluctance machines are able to operate over a large range in speed. A fully loaded SRM is typically designed to saturate the ferromagnetic material that comprises the stator and rotor of the machine whereas a lightly loaded machine does not. Therefore, the model of the machine should be able to handle both a large range in frequency and input excitation levels of the magnetic material in the machine. The development of a new dynamic circuit-based ferromagnetic model is described in this thesis. The investigation of the behaviour of 24 gauge M19 silicon steel led to the conclusion that, for this material, a circuit model that has static parameters is unable to accurately reproduce the behaviour of the actual material over a large range of input frequencies and excitation levels without resorting to retuning the parameters of the model. This thesis provides two new mechanisms that dynamically adjust the resistance values of the flux tubes of the model. Comparisons using a normalized vertical least-squares metric between the newly proposed dynamic model and a model that has static resistance values clearly show the improvement that is gained by using these mechanisms. A practical implementation of the new model is also given. Timing using a general purpose CPU shows that this implementation of the model will most likely be able to be used as part of a multi-phase lumped parameter model for a SRM in realtime. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate
9

Utveckling och validering av en LC-MS/MS metod för kvantifiering av clopidogrel och dess metabolit i plasma

Shamon, Doreen-Marie January 2010 (has links)
<p>Clopidogrel is an antiplatelet substance that prevents blood coagulation in the arteries. It is an inactive pro drug that becomes activated after first-pass metabolism by the liver. The active metabolite of clopidogrel is 2-oxoclopidogrel, which is unstable therefore pharmacokinetic data is obtained by measuring the inactive metabolite clopidogrel acid in plasma. Clopidogrel is taken orally in tablet form. The aim of this project was to develop a LC-MS/MS method for quantification of clopidogrel and its metabolite in plasma.</p><p> </p><p>The method has been developed by optimizing the sample preparation. Different extraction procedures and extraction columns were tested, for example, by changing the extraction column from a C8 silica sorbent to Oasis HLB (a polymer sorbent). Different internal standards were evaluated as a result of discovering the signal suppression of the previous internal standard clopidogrel acid.  Flupentixol was found to be the best candidate.</p>
10

FPGA BASED CONTROL OF HIGH TEMPERATURE SWITCHED RELUCTANCE MOTOR FOR IMPROVING THE INPUT POWER QUALITY

Krishnamurthy, Anush Viswanath 01 January 2004 (has links)
This thesis develops a hardware circuit implementation of a novel algorithm for reducing a SRM drives input current ripple or equivalently to improve the SRM drives input power quality. The algorithm requires the SRMs phase current to follow a trapezoidal trajectory relative to the rotors position with the magnitude of the current dependent on the desired average torque. This thesis deals with the generation of the required current command that is the input to a separate analog current regulator that forces the SRMs current to follow the generated current command. The final circuit design must be capable of operating at 200C to be part of a high temperature aircraft actuator. In this thesis, room temperature hardware is used to emulate and verify the high temperature design. Both a high temperature microcontroller based design and a high temperature gate array based design are considered with the high temperature gate array based design being chosen. Ultimately, a standard room temperature Xilinx FPGA is chosen to emulate the high temperature gate array. The FPGA is programmed using Verilog HDL and the code is downloaded into the chip using Xilinx ISE software. The experimentally generated output is validated by comparing it with simulation results from a detailed Simulink model of the complete drive system.

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