Thesis (Master)--İzmir Institute of Technology, İzmir, 2006. / Includes bibliographical references (leaves. 89-91).

Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Peng Xiong, Florida State University, College of Arts and Sciences, Dept of Physics. Title and description from dissertation home page (viewed Jan. 18, 2005). Includes bibliographical references.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 97-99). Also available via the Internet.

Thesis (Ph.D.)--Drexel University, 2010. / Includes abstract and vita. Includes bibliographical references (leaves 67-80).

Thesis (M.S.)--Texas State University-San Marcos, 2006. / Vita. Appendices: leaves 121-165. Includes bibliographical references (leaves 166-168).

Ph.D. (Physics) / Compounds of rare-earth (RE) elements (Ce, Yb, Eu) as well as actinide element U with partially filled 4f or 5f shells have been receiving considerable attention in the field of low temperature studies. This stems from the diversity of magnetic ground state exhibited by the compounds. These range from non-magnetic, metallic, ferromagnetic or antiferromagnetic ordered state. The nature of the ground state depends on the balance between the on-site Kondo interaction, which mostly favours a local non-magnetic singlet and also the indirect Rudderman-Kittel-Kasuya- Yosida (RKKY) exchange interactions. The interactions of the localized f moments with their environment result in the crystal electric field (CEF) effects at the rare-earth (RE) ion site which splits the free-ion ground-state multiplet. The competing energy scales of CEF splitting, Kondo and RKKY interaction cause the large variety of exceptional phenomena observed in rare earth systems, such as heavy-fermion (HF) behaviour, intermediate valence, unconventional superconductivity, and quantum criticality. Generally, the low-temperature properties of RE systems depend sensitively on the position of the undisturbed 4f state with respect to the Fermi level. Thus, the hybridization between the 4f and conduction-electron states may give rise to either an enhanced density of states (DOS) near the Fermi level in HF metals or to the formation of a gap at Fermi level in Kondo insulators. Recent considerable research interest in strongly correlated electron systems (SCES) studies has been the study of intermetallic compounds close to magnetic instability and the introduction of non-Fermi-liquid (NFL) state. NFL behaviour in f-electron systems is characterized by special power laws and logarithmic divergences in temperature of the physical properties of materials at low temperatures...

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

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Surgically implanted thermoregulating ferromagnetic seeds as a mean of inducing hyperthermia in malignant tumors has been successfully introduced in a clinical environment at the University of Arizona. This work covers topics in quality assurance for the method on two levels. The first level deals with the magnetic induction system where magnetic and electric fields are measured. A discussion on safety levels for patients and treatment personnel is given, and an optically coupled probe for magnetic field measurements is described. The second level treats the electrical characteristics of the ferromagnetic seeds. Systems to measure the permeability and conductivity of the seeds are presented with some typical results. Finally, hysteresis power loss in a seed is measured and compared to losses due to eddy currents.