This thesis deals with the conversion stories of five female converts to Islam; considering the expectations my interlocutors have faced, the pressures to tell a certain type of narrative, the formation of their practice and the stories they choose to narrate. The concept of an ‘epiphany’ narrative, a story of inspiration and divine intervention, will be discussed and placed into tension with ‘rupture’ narratives; the stories my interlocutors tell in order to ‘make sense’ of their conversions.

This thesis deals with the conversion stories of five female converts to Islam; considering the expectations my interlocutors have faced, the pressures to tell a certain type of narrative, the formation of their practice and the stories they choose to narrate. The concept of an ‘epiphany’ narrative, a story of inspiration and divine intervention, will be discussed and placed into tension with ‘rupture’ narratives; the stories my interlocutors tell in order to ‘make sense’ of their conversions.

The quest for energy is leading the industry into drilling deeper wells. Typically, a temperature gradient of 1°C/150 ft can be expected, with bottom hole temperatures reaching beyond 200°C in many areas of the world. Moreover, the increased recovery benefits and cost reductions possible with the use of horizontal and multilateral wells has triggered a need for higher power energy conversion systems in bottom hole assemblies, such as rotary steerable tools and downhole tractors. The concepts developed throughout this work address some of these new needs. This research investigated improvements, novel solutions and considerations that will lead to significant advantages in terms of reliability, extended temperature operation, increased power capability and reduced size and cost of compact harsh environment energy conversion systems. Improvements to both the electromechanical subsystem and the power electronic subsystem are introduced. Air gap viscous losses were shown to a have a significant effect on the optimal design of submersible PM (permanent magnet) machines, and a design procedure to account for this loss component in the design was developed. The application of a dual winding exterior rotor PM machine in a downhole environment enabled a significant increase in the application’s torque capability, provided protection against generator winding over voltage, and reduced parts count. Comprehensive switching device qualification, testing, and simulation lead to a simple failure mitigation technique for the operation of the most suitable devices at elevated temperature. A flying capacitor multilevel inverter was then successfully constructed and temperature tested. A novel motor drive concept suited for elevated temperature oil filled environment applications concluded the research.

This thesis is study about the capability of guided waves in the inspection of cracks in pipelines, and studying about the guided waves of mode conversion phenomenon caused by cracks. The generally used inspection methods in industry are all localized area inspection. It will cost expensively and spend lots of human resource and time consuming, if we want to inspect the whole area in pipelines in factory. Thus, guided waves are used to improve these shortcomings of traditional inspection methods. Guided Waves can propagate fast and long range along the pipelines without decay. With the ability that guided waves can incident at a single location then inspect the whole region of pipelines under efficiently propagating distance. In this thesis, with using laboratory equipment, 3 Toneburst Cycles, 400¡B500¡B600 kHz, and L(0,1)¡BL(0,2) incident mode set up for crack detective sensitivity experiment. By calculating the group velocity of the signals of crack, it is known that there are three separated modes L(0,1)¡BL(0,2) and F(1,2) from reflected waves by cracks. These modes are exactly mode converted by cracks. The results show that in the same crack circumferential length or crack depth, the longer length or the deeper depth cause the higher reflection coefficient. It means they are more sensitive on the inspection of cracks. Also the reflection coefficient increases with the raising cross section area loss of cracks. In two dimensional fast Fourier transform experiment (2-D FFT), with 3 Toneburst Cycles, 400¡B500¡B600 kHz, L(0,1)¡BL(0,2) incident mode, and 0.5 cm interval set up to gather 40-point signals for proceeding the experiment. It can separate signals with different group velocity which are mixing together in time domain. From results, there are three different modes L(0,1)¡BL(0,2) and F(1,2) mode separated at three-dimensional picture. Finally, using the guided waves inspection system with 3 toneburst, 90 kHz and T(0,1) incident mode set up to proceed the experiment as before. In inspecting crack sensitive experiment, the use of this system has the similar result with the use of laboratory equipment. It proves that the excellent capability of guided waves in inspection of cracks in pipelines. While in mode identification, this system can identify there is only T(0,1) and F(1,2) mode with the same group velocity exist. Then the same result is verified by 2-D FFT experiment. It shows that this system generate or receive the specific mode in detection cracks by phase construction or phase destruction of phase interference.

In this thesis, we present the phase-intensity conversion transmission method for the first time. We analyze phase-intensity conversion theory, laser diode noise, and EDFA noise. By experiment, we investigate the impact of the parameters in phase-intensity conversion such as light source linewidth, phase modulation index, dispersion magnitude, and EDFA on the system performance. We successfully demonstrated simultaneous transmission of one AM-VSB channel through intensity modulation and one QAM channel through phase modulation over 10 km single mode fiber using LiNbO3 external modulator. The system performance with CNR of 57~61 dB for the AM-VSB channel and BER of 6.8´10-9 for the QAM channel can be achieved. The demonstration and the experimental results confirm the feasibility of phase-intensity conversion techniques. Potentially, the phase-intensity conversion transmission method could be applied on optical encryption and decryption systems.

All-optical wavelength conversion is necessary for efficient managing and routing optical signals in a complex all-optical network model. With the bit-rate increases as time evolves, all-optical conversion will become more promising due to its high transparency for data rate and format and the low cost penalty compared with O/E/O method. Periodically poled LiNbO3 crystal fiber (PPLNCF) for wavelength conversion is successfully grown by LHPG method with in situ electric field bias. The pitch depends on the frequency of applied external electric field. Domain period of 9.76 microms and crystal length over 160 mm are demonstrated in this thesis. Electrically induced micro-swing during growth is managed to assist poling process. After the optical test, 0.27% peak offset shows the accuracy of our fabrication. The wavelength and temperature bandwidths were measured to be 17.2 nm and 42.8oC. With the improvement of uniformity, broadband design, and the implementation of guiding structure, high quality PPLNCF will be widely promoted for its superior performance.

Th.--Katholieke universiteit van Nijmegen, 2001. / Contient un résumé en néerlandais. Bibliogr. p. 219-237.

Dissertation--Mainz--Universität, 2005. / Bibliogr. p. 401-417.

Texte remanié de: Dissertation--Theologische Fakultät--Berlin--Humboldt-Universität, 2003. / Bibliogr. p. 519-549.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009. / Title from title screen (site viewed October 13, 2009). PDF text: xiv, 183 p. : ill. (some col.) ; 1 Mb. UMI publication number: AAT 3358961. Includes bibliographical references. Also available in microfilm and microfiche formats.