published_or_final_version / Chemistry / Master / Master of Philosophy

published_or_final_version / Chemistry / Master / Master of Philosophy

published_or_final_version / Chemistry / Master / Master of Philosophy

published_or_final_version / Chemistry / Master / Master of Philosophy

The thesis describes development and optimization process of an inductively coupled coil corrosion potential sensor for long-term civil structure health monitoring remotely. This is of growing interest for decreasing the maintenance cost, reducing the deterioration significantly and increasing the safety. The thesis is organized accordingly introduction, circuit modeling of the sensor, optimization and fabrication of the sensors and the simulated and experimental results from new and existing civil structure. The two geometrical design, cylindrical shape and Printed Circuit Board (PCB) based sensor parts of this research and their encapsulation technique for long-term enduring in harsh and corrosive environment of the civil infrastructure is described in the thesis. Results of an accelerated corrosion test on an embedded cylindrical shaped sensor indicates that the corrosion potential can be monitored with less than 10 mV resolution with a sensor sensitivity of ~0.73 kHz/mV. The last part describes a novel technique for a PCB sensor to simulate the existing structure already contaminated with corrosive substances such as chlorides. Two encapsulation techniques, non-conductive epoxy sealed and PLEXIGLAS with air gap sealed embedded PCB sensors response are compared from the accelerated corrosion test on new and built-in civil structure. Finally, results from the accelerated corrosion tests using the two encapsulation techniques mentioned above demonstrate that the embedded sensor in an existing structure may take up to 60 days to see the significant corrosion with a sensor sensitivity of ~ 1.53 kHz/mV or ~ 1.63 kHz/mV respectively. Since chlorides take many years to diffuse into concrete used for civil structures these sensors will respond fast enough to be used in existing structures as well as in new structures.

Amazonitic K-feldspar is characteristic of evolved granitic pegmatites of NYF (niobium-yttrium-fluorine) type, associated with A-type granite emplacement. In this work, I focus on four notable examples of such an association: (1) West Keivy, Kola Peninsula, Russia, (2) Saint-Ludger-de-Milot, Quebec, (3) Lac Sairs, Quebec, and (4) Morefield, Virginia. A fifth locality, the Broken Hill metamorphosed exhalative-type volcanogenic deposits in Australia, is an unusual type of amazonitic K-feldspar formed in an ore environment. A total of nineteen samples of amazonitic K-feldspar were characterized geochemically and mineralogically on the basis of X-ray diffraction, electron-microprobe and laser-ablation ICP-MS analyses. Lead, as an essential requirement for formation of the blue-green amazonitic color, has received particular attention. In every case, the analytical data show elevated amounts of Pb and rare alkalis, which strongly partition into the K-rich phase of the perthite intergrowth. Unusual micrometric grains, highly enriched in Pb, are found in cracks in the material from West Keivy. Some of the grains represent a new mineral species, a Pb-dominant feldspar. The presence of amazonitic K-feldspar in a granitic pegmatite is more than a curiosity. It can shed light on important petrogenetic issues such as metasomatic rejuvenation of crustal rocks prior to regional melting in a period of extension.

Thesis (Master)--İzmir Institute of Technology, İzmir, 2005 / Keywords: ICP-OES, Chemometrics methods, internal standardization, matrix effects. Includes bibliographical references (leaves. 111-120).

Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaf 153).

Thesis (M. Phil.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 154).

Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 147).