M.Sc.(Chemistry) / Fourier transform infrared and ultraviolet-visible spectroscopy were used in this study. The relative merits of dispersive and interferometric instrumentation were investigated and the latter revealed a dramatic improvement in accuracy. In the infrared study transmission and diffuse reflectance techniques were used and compared. The diffuse reflectance technique provides more information regarding surface species, like OH-groups and interactions between adsorbent and adsorbate, than the transmission technique ...

Thesis (M.Phil.)--Chinese University of Hong Kong. / Bibliography: leaf 61.

A Fourier Transform Spectrometer (FTS) is an interferometric instrument configured so that the optical spectrum of the input to the instrument can be determined from the Fourier transform of the output. Spectral resolution is proportional to the maximum path differences in the interferometer. The Kitt Peak 1-Meter FTS is a high resolution instrument featuring a one-meter maximum path difference. The instrument is of the continuous motion type and utilizes equal time sampling of the interferogram. Realization of the potential of a one-meter path difference instrument requires very precise path difference positioning. Static and dynamic position accuracies of approximately seven Angstrom units are achieved in this instrument. Path difference command and control is accomplished through use of phase-lock techniques. A key element in the implementation is a Zeeman frequency stabilized Zeeman laser. Stabilization is accomplished by phase-locking the Zeeman frequency to a quartz crystal controlled system reference frequency. Path position information is derived by a control position interferometer which utilizes the Zeeman laser so that one cycle in phase at the Zeeman frequency corresponds to one wavelength in path difference at the laser optical frequency. Position control is achieved by phase-locking the output of the position control interferometer to a command signal. The command signal is synthesized from the laser Zeeman frequency by an additional phase-lock loop. Two approaches to minimizing spectral ghosts resulting from velocity errors are developed. One technique is applicable to band-pass designs. The second optimizes response of low-pass designs that include a single high-pass pole to reject the average value of the interferogram. Both techniques result in ghost responses improved by factors of at least ten to one-hundred compared with those of conventional data filters. The instrument includes an autoranging analog-to-digital converter with fifteen bits of resolution and total range of twenty-two bits developed to cope with the large dynamic range of the interferogram. These efforts together with careful design and construction have resulted in a powerful instrument which is in active use.

Thesis (M.S.)--Eastern Illinois University, 2008. / Includes bibliographical references (pp. 16, 30, 49, 69, 95, 126).

Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 94-98).

Chapter II of this thesis describes the operation of a Fourier Transform Ion Cyclotron Resonance Spectrometer. Included is a detailed discussion of software which was developed to run the spectrometer and analyze the data. An automatic data acquisition system for kinetic experiments is also described. Chapter III contains a short discussion of discrete versus continuous methods of data acquisition and problems with the FT-ICR method which utilizes discrete sampling. Two techniques are discussed which have been found to solve problems associated with a digital system, acquisition by "mixing" and zero-filling. Also, mass calibrations done on the FT-ICR spectrometer are presented. The reactions of some negative ions with esters in the gas phase have been studied by FT-ICR and are discussed in Chapter IV. The reactions of ¹⁸0 labelled methoxide with methyl trifluoroacetate, methyl benzoate, dimethyl carbonate, diethyl carbonate and dipropyl carbonate have been studied. It was found that there is incorporation of ¹⁸0 in product ions of the form RCOO⁻ showing that methoxide attacks esters in the gas phase partially at carbonyl carbon. Product distributions are found to be consistent with two competing mechanisms, B[sub AC]2 and S[sub N]2. Thus it was found that CH₃•0⁻ reacts with C₆H₅COOCH₃- 92% by a B[sub AC]2 type mechanism and 8% by an S[sub N]2 type mechanism. The amount of ¹⁸0 incorporation in product ions was seen to decrease with the presence of β hydrogens, due to the presence of an elimination channel. The reaction of ethoxide with the above named esters was studied and the products are also interpreted in terms of three competing mechanisms, B[sub AC]2, S[sub N]2 and elimination. / Science, Faculty of / Chemistry, Department of / Graduate

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Adibi, Ali; Committee Member: Chang, Gee-Kung; Committee Member: Ralph, Stephen; Committee Member: Trebino, Rick; Committee Member: Verriest, Erik I.

Thesis--University of Oulu, 1985. / Includes bibliographical references (p. [21]-22).

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