Thesis (Ph. D.)--Michigan State University. Electrical Engineering, 2008. / Title from PDF t.p. (Proquest, viewed on Aug. 17, 2009) Includes bibliographical references (p. 120-135). Also issued in print.

Thesis (M. Eng.), Memorial University of Newfoundland, 1998. / Restricted until November 1999. Bibliography: leaves 22-25.

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2006. / Levent Degertekin, Committee Member ; William P. King, Committee Member ; Boris Mizaikoff, Committee Member ; Mark G. Allen, Committee Member ; Peter J. Hesketh, Committee Chair.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: orbital trajectory, ion collection, turning point method, spherical probes, turning angle, ion scattering, cylindrical probes. Includes bibliographical references (p.60-63).

Made available in DSpace on 2014-06-11T19:22:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-10-04Bitstream added on 2014-06-13T19:48:53Z : No. of bitstreams: 1 junqueira_mvn_me_ilha.pdf: 2490518 bytes, checksum: 7e14b1f52c086453d1a4b7b8750cb97e (MD5) / Foi desenvolvido um Eletroestimulador Funcional Microcontrolado para geração de movimentos nos membros inferiores de paraplégicos, visando acelerar o processo de reabilitação. O estimulador neuromuscular é constituído por oito canais microcontrolados, com formas de onda de corrente bifásica, retangular e carga balanceada, com capacidade para fornecer correntes com amplitude de até 140 mA, utilizando modulação por largura de pulso (PWM). Foi implementado um controlador Proporcional Integral Derivativo (PID) embarcado para uso com o eletroestimulador, sendo possível determinar a energia a ser aplicada ao membro estimulado, de forma a mantê-lo em uma posição pré-estabelecida. O projeto desse controlador se baseou em um modelo matemático linear de segunda ordem, que representa o comportamento da força muscular devido a um estímulo elétrico. Para validação e teste do funcionamento do sistema, funções matemáticas que descrevem o comportamento fisiológico do membro inferior foram representadas por circuitos eletrônicos. Desta forma, neste projeto foi possível integrar o controlador, o estimulador e o modelo fisiológico do músculo, observando-se a resposta temporal durante a eletroestimulação, descartando, inicialmente, a realização de testes com pessoas, visando preservar a integridade física dos voluntários. Após a verificação do bom funcionamento do equipamento, realizou-se testes com voluntários aplicando o controle em malha fechada / A Microcontrolled Functional Electrical Stimulation (FES) system was developed for generating movements in the lower limbs of paraplegics in order to accelerate their rehabilitation process. The neuromuscular stimulator consists of eight channels, microcontrolled, rectangular, biphasic current waveform, balanced load, with the ability to deliver current with amplitude of 140 mA using pulse width modulation (PWM). A PID controller was implemented for using with the microcontrolled stimulator, and the energy to be applied to the stimulated member can be determined in order to keep the leg in a pre-determined position. The design of this controller was based on a linear second order mathematical model, which describes the behavior of a muscle strength due to an electrical stimulus. For validation and testing the microcontrolled electrical stimulator system, mathematical functions that represent the physiological behavior of the lower limbs were represented by electronic circuits. Thus, this project integrates the controller, the stimulator and the muscle model, observing the time response during electrical stimulation, avoiding testing it with patients and preserving the physical integrity of the volunteers. After verifying the proper operation of the equipment, tests with volunteers were carried out applying closed loop control

Thesis (Masters Diploma (Electrical Engineering)--Cape Technikon, Cape Town, 1993 / In the last decade the advertising industry has developed into an advanced science which increasingly relies on the use of electronic utilities and modern technology. The advent of the microcontroller has made it possible to incorporate electronic intelligence into advertising utilities. This thesis describes the design, development and functioning of a stand alone programmable electronic message display as required by the Electrical Engineering Department of the Cape Technikon.

Orientador: Aparecido Augusto de Carvalho / Banca: Carlos Antonio Alves / Banca: Uender da Costa Faria / Resumo: Foi desenvolvido um Eletroestimulador Funcional Microcontrolado para geração de movimentos nos membros inferiores de paraplégicos, visando acelerar o processo de reabilitação. O estimulador neuromuscular é constituído por oito canais microcontrolados, com formas de onda de corrente bifásica, retangular e carga balanceada, com capacidade para fornecer correntes com amplitude de até 140 mA, utilizando modulação por largura de pulso (PWM). Foi implementado um controlador Proporcional Integral Derivativo (PID) embarcado para uso com o eletroestimulador, sendo possível determinar a energia a ser aplicada ao membro estimulado, de forma a mantê-lo em uma posição pré-estabelecida. O projeto desse controlador se baseou em um modelo matemático linear de segunda ordem, que representa o comportamento da força muscular devido a um estímulo elétrico. Para validação e teste do funcionamento do sistema, funções matemáticas que descrevem o comportamento fisiológico do membro inferior foram representadas por circuitos eletrônicos. Desta forma, neste projeto foi possível integrar o controlador, o estimulador e o modelo fisiológico do músculo, observando-se a resposta temporal durante a eletroestimulação, descartando, inicialmente, a realização de testes com pessoas, visando preservar a integridade física dos voluntários. Após a verificação do bom funcionamento do equipamento, realizou-se testes com voluntários aplicando o controle em malha fechada / Abstract: A Microcontrolled Functional Electrical Stimulation (FES) system was developed for generating movements in the lower limbs of paraplegics in order to accelerate their rehabilitation process. The neuromuscular stimulator consists of eight channels, microcontrolled, rectangular, biphasic current waveform, balanced load, with the ability to deliver current with amplitude of 140 mA using pulse width modulation (PWM). A PID controller was implemented for using with the microcontrolled stimulator, and the energy to be applied to the stimulated member can be determined in order to keep the leg in a pre-determined position. The design of this controller was based on a linear second order mathematical model, which describes the behavior of a muscle strength due to an electrical stimulus. For validation and testing the microcontrolled electrical stimulator system, mathematical functions that represent the physiological behavior of the lower limbs were represented by electronic circuits. Thus, this project integrates the controller, the stimulator and the muscle model, observing the time response during electrical stimulation, avoiding testing it with patients and preserving the physical integrity of the volunteers. After verifying the proper operation of the equipment, tests with volunteers were carried out applying closed loop control / Mestre

A "gradient probe" consisting of two search coils has been developed to measure the current density in a pulsed plasma. This probe measures both the magnitude and the gradient of the magentic field simultaneously enabling more accurate measurements than the conventional magnetic probe which has only one coil. It has been used to measure the current densities and the magnetic fields in z-pinch discharges in helium at pressures between 500μ and 4 mmHg. The collapse curves obtained agreed with the predictions of a modified snow-plow equation which allowed for the loss of particles from the collapsing current shell. The flow of current in the plasma is distorted by the presence of a probe. Such an effect spoils the spatial resolution so that the measured values of the current density Jp are averages of the true current density J₀ over a finite region. To investigate this, a correction formula which relates Jp to J₀ has been developed. Our error analyses showed that any scatter in Jp due to experimental errors was magnified twenty times in J₀. For a pulsed plasma, therefore, one should try to reduce the perturbation of the probe instead of relying on the correction procedure. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Recent theoretical and numerical investigations revealed the prospect that the instantaneous total temperature is nonuniform around vortices. For low Mach number flows, the instantaneous total pressure was also shown to become nonuniform in such a similar manner that the near-wake patterns of instantaneous total pressure exhibit almost exact facsimiles of these of total temperature. Here, the time-accurate measurements of the fluctuating total temperature and pressure are presented by placing an aspirating probe in the vortex street behind a cylinder. The data, obtained at a uniform upstream Mach number of 0.4 and with the vortex street in its natural (unexcited) state, show a significant fluctuation of total temperature and pressure. In addition, their time-traces taken in the near-wake are qualitatively similar. / M.S.

The problem with which this investigation was concerned was that of determining the use of modern automotive tune-up equipment as used by the automotive garages in the Fort Worth area. The data for this study were provided by fifteen garages of the Fort Worth area. Of the Fort Worth garages using electronic equipment to perform a tune-up, few appear to have the adequate equipment and few appear to make more use of the equipment. In addition, a deficiency seems evident in the use of the electronic computer in performing tune-ups.