Suzanne E. Bell

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Infrared optical constants collected from the literature are tabulated. The data for the noble metals and Al, Pb, and W can be reasonably fit using the Drude model. It is shown that -epsilon1(omega) = epsilon2(omega) approximately omega(2)(p)/(2omega(2)(tau)) at the damping frequency omega = omega(tau). Also -epsilon1(omega(tau)) approximately - (1/2)(More)
Neural networks were trained using whole ion mobility spectra from a standardized database of 3137 spectra for 204 chemicals at various concentrations. Performance of the network was measured by the success of classification into ten chemical classes. Eleven stages for evaluation of spectra and of spectral pre-processing were employed and minimums(More)
Normal and cyclic alkanes and alkenes form stable gas-phase ions in air at atmospheric pressure from 40 to 200°C when moisture is below 1 ppm. Ionization of alkanes in a (63)Ni source favored charge transfer over proton transfer through pathways involving [M-1](+) and [M-3](+) ions. Ion mobility spectra for alkanes showed sharp and symmetrical profiles(More)
A minimal neural network was applied to a large library of high-temperature mobility spectra drawn from 16 chemical classes including 154 substances with 2000 spectra at various concentrations. A genetic algorithm was used to create a representative subset of points from the mobility spectrum as input to a cascade-type back-propagation network. This network(More)
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