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Thermoionization And Dissociation Of Fullerenes And Endohedral Fullerenes, Rongping Deng

Doctoral Dissertations

Electron emission and unimolecular dissociation of energetically excited fullerenes and endohedral fullerenes are studied with mass spectrometry. Three experimental approaches have been developed for these studies. These are UV laser excitation time-of-flight mass spectrometry (TOF-MS), laser desorption and ionization mass spectrometry (LDI-MS), and ion-molecule collision mass spectrometry (IMC-MS).

Our first experimental effort is to investigate delayed electron emission from multiphoton excited C60 molecules. A lower limit of the probability of electron emission from multiphoton excited C60 molecules is determined to be about 2.6%. This result indicates that electron emission is not merely parasitic to dissociation.

The second experimental effort is …

Active Disturbance Cancellation In Nonlinear Dynamical Systems Using Neural Networks, John C. Canfield

Doctoral Dissertations

A proposal for the use of a time delay CMAC neural network for disturbance cancellation in nonlinear dynamical systems is presented. Appropriate modifications to the CMAC training algorithm are derived which allow convergent adaptation for a variety of secondary signal paths. Analytical bounds on the maximum learning gain are presented which guarantee convergence of the algorithm and provide insight into the necessary reduction in learning gain as a function of the system parameters. Effectiveness of the algorithm is evaluated through mathematical analysis, simulation studies, and experimental application of the technique on an acoustic duct laboratory model.

Wavelet Analysis Of Ulf Magnetospheric Waves, Edward Scott Brennison

Doctoral Dissertations

Wavelet analysis is used to analyze magnetometer data and is compared to the traditional spectrogram technique, in particular, with respect to structured Pc 1--2 emissions. This results in the conclusion that the frequency modulation evident in Pearl pulsations is not continuous, but is comprised of waves localized in both time and space whose overall structure produces the stripe-like patterns. Utilizing information from the Multi-Resolution Analysis in conjunction with traditional spectrogram techniques this paper is the first to show clear signal power relationships between Pc 1--2 and Pc3 waves and also between Pc 1--2 and Pc 5 waves as detected on …

The Central New England Sea Breeze Study, Samuel T K Miller

Doctoral Dissertations

The synoptic and mesoscale environments conducive to the formation of sea breezes were examined, as well as the spatial and temporal evolution of sea-breeze circulations, gravity currents, and fronts along the central New England coast. Sea breeze events were defined as occurring when the observed surface wind direction began the day outside the southeast quadrant, shifted to southeast by afternoon, then shifted back out of the southeast quadrant in the evening, driven by mesoscale, insolation-induced cross-shore temperature gradients.

The meso-alpha (200--2000 km) sea-breeze forcing in the study area was defined as a combination of the cross-shore potential temperature gradient (deltatheta/deltax) …