A fiber optic fluorometer utilizing a double-fiber optic probe was constructed. The absolute fluorescence signal and effective collection efficiency are approximately one fifth those of typical cuvette fluorometers and agree with those predicted by theory. A quinine sulfate calibration curve shows linearity from a detection limit of 10 pg/mL to 10 μg/mL. Single- and double-fiber probe configurations were also compared. The double-fiber configuration provided better detection limits due to its superior signal-to-background ratio. A discussion of sensor methodology for the monitoring of reaction intermediates is presented and a simple kinetic model for predicting the time dependent response of such sensors is developed. Two possible mechanisms for the Fujiwara reaction with chloroform are discussed. The effect of pyridine, water, and base concentrations on reaction kinetics was evaluated to develop single-phase Fujiwara reagent mixtures for both fluorometric and spectrophotometric determinations of chloroform. A unique "continuous-exposure" apparatus allowing vapor phase transport of chloroform from an aqueous sample to a conventional cuvette was constructed. The spectrophotometric detection limit for chloroform is 11 ng/mL and the method was shown to be suitable for the analysis of tap water. Two fiber optic chemical sensors (FOCS) for the detection of chloroform were developed. An aliquot of the optimized fluorometric reagent solution is held in contact with the fiber optic probe within a light-tight enclosure and is isolated from a bulk sample by a trapped headspace. One FOCS utilizes 1.3 mL of reagent held in a reservoir and the other utilizes a 10-μL drop of reagent suspended on the sensing tips of the fiber optic probe. Chloroform vapor from the sample migrates into the FOCS and reacts with the reagent to produce a fluorescent reaction intermediate which is monitored at 590 nm; the rate of increase in the fluorescence signal is related to chloroform concentration. Both FOCSs give detection limits better than 0.1 ng/mL. The response and total measurement times are comparable for the two FOCSs, and the duration of the linear response is limited by inner-filter effects. The response to a number of volatile GPHHCs including the trihalomethanes are reported. Analyses of tap water for chloroform with the reservoir FOCS and GC/MS were in excellent agreement. / Graduation date: 1992

This thesis addresses the hypothesis that unobtrusive monitoring of daily living could be used to evaluate changes in the health status of frail elderly people living alone at home. Low cost motion sensors can be used for monitoring the long term trends in occupant?s well-being in terms of physical, mental, social and environmental factors. The monitored data can be used to quantitatively measure parameters that can provide insight into the level of activity and functional ability of the subject. Any deviations in these parameters can provide information on the changing health status of the subject. This thesis attempts for the first time to establish a mathematical and statistical framework for the monitoring of functional health status in the home using a network of wireless sensors to monitor occupancy in each room of the house. A low power and low cost, unobtrusive occupancy monitoring system using ZigBee wireless technology and passive infrared sensors has been developed by the Biomedical Systems Laboratory at the University of New South Wales. The essence of the occupancy monitoring system is to detect variations in the activities of daily living (ADL) of elderly people living alone at home. The finite state, discrete parameter, time homogeneous Markov chain represents a theoretical framework for an unobtrusive occupancy monitoring system. An implementation of this framework for monitoring occupancy pattern is presented in real time use. The system was evaluated in a series of field studies in laboratory and home environment, in supervised and unsupervised settings, using cohorts of healthy elderly subjects living alone in their homes in community dwelling setting. A pilot trial was conducted in which four healthy elderly subjects living alone had PIR motion sensors installed in their homes at strategic points for a period of up to 13 weeks. The functionality of the system was evaluated over a domain of basic daily activities. A profile of the activities, in real time environment, for different times and days was stored as transition probability matrices. Automatic techniques for interpreting the test data captured by the system in terms of human movements were evaluated and compared with the wellness profile of the subject. Trial results exhibited that clinically significant model parameters were able to detect longitudinal deviations in the functional health status of elderly people.

Abstract In New Zealand there are currently no regular external audits to verify the full treatment chain in radiotherapy. This thesis reports on a project to devise such an audit procedure suitable to assess the accuracy of the delivery of prescribed radiotherapy doses to patients over the full treatment process. The National Radiation Laboratory (NRL), regulatory authority, will use the method developed to conduct biennial audits of all radiotherapy centres. A commercial chest phantom with a MOSFET dosimetry system was provided for this project. The MOSFETs were commissioned and their characteristics determined, namely reproducibility, energy dependence and angular dependence. The MOSFETs were also tested in a clinical environment with the phantom. Measurements were carried out to test the MOSFET capabilities in both lung and soft tissue in the phantom. Two plans were devised for the audit process, a straightforward one with two parallel opposed beams and a more complex one involving lung tissue and wedges. These plans were designed to test the entire treatment planning and delivery process. It was found that each MOSFET detector needed to be individually calibrated. Reproducibility was found to have an average standard deviation of 2% on standard sensitivity and 1.2% on high sensitivity. The angular dependence of the detectors showed that when the MOSFET was rotated by 90 degrees to the beam axis a drop in response of 3% was observed with 6 MV. The energy dependence factor was constant within uncertainty for all MOSFETs. Overall, the MOSFET and phantom dosimetry system was determined to be suitable for the audit. The measurements with phantom showed that doses in high dose regions could be determined accurately. The greatest variation from the Treatment Planning system dose to the measured dose was 6%. The trial runs of the audit in two New Zealand radiotherapy centres showed that the procedure created is able to find discrepancies within the desired 5%, recommended by the ICRU, in the prescribed dose to the phantom.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M.S.)--State University of New York at Binghamton, Materials Science, 2006. / Includes bibliographical references (leaves 62-64).

Thesis (Ph. D.)--University of Nevada, Reno, 2006. / "May, 2006." Includes bibliographical references. Online version available on the World Wide Web.

Thesis (Ph.D.)--Tufts University, 2001. / Adviser: David R. Walt. Submitted to the Dept. of Chemistry, Includes bibliographical references (leaves 197-208). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (M.S.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (leaves 63-66).

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on February 14, 2008) Vita. Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 187-195). Also available via the Internet.