An escaping alpha collector probe has been developed for TFTR`s DT phase. Energy distributions of escaping alphas have been determined by measuring the range of {alpha}-particles implanted into nickel foils located within the alpha collector. Results at 1.0 MA of plasma current are in good agreement with predictions for first orbit alpha loss. Results at 1.8 MA, however, show a significant anomalous loss of partially thermalized alphas (in addition to the expected first orbit loss), which is not observed with the lost alpha scintillator detectors in DT plasmas, but does resemble the anomalous delayed loss seen in DD plasmas. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations. An experiment designed to study the effect of plasma major radius shifts on {alpha}-particle loss has led to a better understanding of {alpha}-particle dynamics in tokamaks. Intuitively, one might suppose that confined marginally passing {alpha}-particles forced to move toward higher magnetic field during an inward major radius shift (i.e., compression) would mirror and become trapped particles, leading to increased alpha loss. Such an effect was looked for during the shift experiment, however, no significant changes in alpha loss to the 90{degree} lost alpha scintillator detector …

In this thesis the author discusses the methodology for doing photometry: from procedure of extracting supernova counts from images that contain combined supernova plus galaxy flux, to standard star calibration, to additional instrumental corrections that arise due to the multiple telescopes used for observations. He discusses the different sources of photometric error and their correlations, and the construction of the covariance matrix for all the points in the light curve. He then describes the K corrections which account for the redshifting of spectra that are necessary to compare the photometry of the high-redshift data with those from nearby (z < 0.1) supernovae. Finally, he uses the first seven of the supernovae to test the hypothesis that they live in an under-dense bubble where the locally measured Hubble constant differs significantly from the true Hubble constant. He also uses the data to place limits on the value of the Hubble constant. Discussions of several other important aspects of the data analysis are or will be included in other papers. These topics include a description of how the covariance matrix is used to generate light-curve fits, a discussion of non-photometric systematic errors that also effect the measurements, and a discussion of the …

Two devices, an occupational carbon monoxide (CO) dosimeter (LOCD), and an indoor air quality (IAQ) passive sampler were developed for use in population-based CO exposure assessment studies. CO exposure is a serious public health problem in the U.S., causing both morbidity and mortality (lifetime mortality risk approximately 10{sup -4}). Sparse data from population-based CO exposure assessments indicate that approximately 10% of the U.S. population is exposed to CO above the national ambient air quality standard. No CO exposure measurement technology is presently available for affordable population-based CO exposure assessment studies. The LOCD and IAQ Passive Sampler were tested in the laboratory and field. The palladium-molybdenum based CO sensor was designed into a compact diffusion tube sampler that can be worn. Time-weighted-average (TWA) CO exposure of the device is quantified by a simple spectrophotometric measurement. The LOCD and IAQ Passive Sampler were tested over an exposure range of 40 to 700 ppm-hours and 200 to 4200 ppm-hours, respectively. Both devices were capable of measuring precisely (relative standard deviation <20%), with low bias (<10%). The LOCD was screened for interferences by temperature, humidity, and organic and inorganic gases. Temperature effects were small in the range of 10{degrees}C to 30{degrees}C. Humidity effects were …

This dissertation describes a methodology and example implementation for the dynamic regulation of temporally overlapping auditory messages in computer-user interfaces. The regulation mechanism exists to schedule numerous overlapping auditory messages in such a way that each individual message remains perceptually distinct from all others. The method is based on the research conducted in the area of auditory scene analysis. While numerous applications have been engineered to present the user with temporally overlapped auditory output, they have generally been designed without any structured method of controlling the perceptual aspects of the sound. The method of scheduling temporally overlapping sounds has been extended to function in an environment where numerous applications can present sound independently of each other. The Centralized Audio Presentation System is a global regulation mechanism that controls all audio output requests made from all currently running applications. The notion of multimodal objects is explored in this system as well. Each audio request that represents a particular message can include numerous auditory representations, such as musical motives and voice. The Presentation System scheduling algorithm selects the best representation according to the current global auditory system state, and presents it to the user within the request constraints of priority and maximum …

This dissertation describes two-dimensional nuclear magnetic resonance theory and experiments which have been developed to study quadruples in the solid state. The technique of multiple-quantum magic-angle spinning (MQMAS) is extensively reviewed and expanded upon in this thesis. Specifically, MQMAS is first compared with another technique, dynamic-angle spinning (DAS). The similarity between the two techniques allows us to extend much of the DAS work to the MQMAS case. Application of MQMAS to a series of aluminum containing materials is then presented. The superior resolution enhancement through MQMAS is exploited to detect the five- and six-coordinated aluminum in many aluminosilicate glasses. Combining the MQMAS method with other experiments, such as HETCOR, greatly expands the possibility of the use of MQMAS to study a large range of problems and is demonstrated in Chapter 5. Finally, the technique switching-angle spinning (SAS) is applied to quadrupolar nuclei to fully characterize a quadrupolar spin system in which all of the 8 NMR parameters are accurately determined. This dissertation is meant to demonstrate that with the combination of two-dimensional NMR concepts and new advanced spinning technologies, a series of multiple-dimensional NMR techniques can be designed to allow a detailed study of quadrupolar nuclei in the solid state.