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The Raman spectrum of polycrystalline or matrix-isolated S₂N₂ shows three bands attributable to its Raman active fundamentals, including two in close proximity; the possibility of Fermi resonance is discounted. The infrared spectrum.of polycrystalline S₂N₂ shows five bands, including three attributable to the infrared active fundamentals, while the others are associated with some intermediate species in the polymerisation of S₂N₂. The vibrational spectra of matrix-isolated S₄N₄ are consistent with previous observations in the solid state and in solution, also with the established cage structure of the molecule. The stretching force constants of S₂N₂ and S₄N₄, lower than those predicted on the basis of observations on acyclic S-N molecules, are correlated with the strain in the molecules and their associated thermodynamic instability. The interaction force constants indicate delocalised π-bonding, apparently more extensive in S₂N₂. Substantial cross-ring S-S bonding is evident in S₄N₄; S-S interactions in S₂N₂ are apparently non-bonded and repulsive in nature. The infrared spectrum of matrix-isolated Cr0C1₃ contains bands attributable to the fundamentals of this molecule, along with several indicating the presence of Cr0₂C1₂ and possibly other related molecules. The Raman spectrum shows just three strong bands, all below 250 cm^-1, assumed to arise from the deformation fundamentals of Cr0C1₃; the form of the spectrum is attributed to absorption or fluorescence. The force constants derived for Cr0C1₃ correspond closely to their counterparts in V0C1₃ and Cr0₂C1₂, suggesting similar force fields in the three molecules. The infrared spectrum of the volatile products of the reaction between PC1₃ and NaN₃ indicates the presence of several molecules, possibly including C1₂PN₃ and oligomers of C1₂ P = N, although no definite conclusions are drawn. Spectroscopic evidence also suggests that the reaction between (CH₃)₂PC1 and NaN₃ yields (CH₃)₂PN₃ as a major product, although observations such as the effect of ultraviolet photolysis remain unexplained.

No description available.

In this thesis, I present an experimental study of quantum control techniques for transferring population between vibrational states of atoms trapped in an optical lattice. Results from a range of techniques are compared, including techniques tested previously in the same system. In the study of the Adiabatic Rapid Passage (ARP) technique, control of population transfer is realized through varying the chirp rate and modulation amplitude of a frequency-chirped sinusoidal displacement of the lattice. Meanwhile, dependence of population transfer on the chirp direction is observed, which is explained by a model of ARP in a 3-level system. In the study of the coherent control technique, interference between a one-phonon transition at 2\omega and a two-phonon transition at omega is experimentally demonstrated. The omega and 2\omega transitions are realized by sinusoidally displacing the optical lattice at omega and sinusoidally modulating the lattice depth at 2\omega, respectively. The branching ratio of transitions to the first excited state and to higher excited states is controlled by varying the relative phase between these two pathways. The highest measured branching ratio of 17\pm2 is achieved among all the experiments using this coherent control scheme. In the study of the GRadient Ascent Pulse Engineering (GRAPE) technique, a "pulse" involving both displacement and depth-modulation of the lattice is used to transfer population. This pulse is theoretically engineered with the GRAPE algorithm to optimize the fidelity between the first excited state and the final state, when the lattice Hamiltonian without gravity for a specific lattice depth is considered. The experimental result shows that there is almost no excitation into higher excited states during population transfer from the ground to the first excited state, even when this process is affected by gravity and inhomogeneous broadening in reality. By comparing all the techniques, the GRAPE technique is found to be the best in terms of increasing population transfer into the first excited state while reducing excitation into higher excited states. On the other hand, the ARP technique creates the highest normalized population inversion, a ratio of the difference to the sum of the ground and the first excited state populations.

In this thesis, I present an experimental study of quantum control techniques for transferring population between vibrational states of atoms trapped in an optical lattice. Results from a range of techniques are compared, including techniques tested previously in the same system. In the study of the Adiabatic Rapid Passage (ARP) technique, control of population transfer is realized through varying the chirp rate and modulation amplitude of a frequency-chirped sinusoidal displacement of the lattice. Meanwhile, dependence of population transfer on the chirp direction is observed, which is explained by a model of ARP in a 3-level system. In the study of the coherent control technique, interference between a one-phonon transition at 2\omega and a two-phonon transition at omega is experimentally demonstrated. The omega and 2\omega transitions are realized by sinusoidally displacing the optical lattice at omega and sinusoidally modulating the lattice depth at 2\omega, respectively. The branching ratio of transitions to the first excited state and to higher excited states is controlled by varying the relative phase between these two pathways. The highest measured branching ratio of 17\pm2 is achieved among all the experiments using this coherent control scheme. In the study of the GRadient Ascent Pulse Engineering (GRAPE) technique, a "pulse" involving both displacement and depth-modulation of the lattice is used to transfer population. This pulse is theoretically engineered with the GRAPE algorithm to optimize the fidelity between the first excited state and the final state, when the lattice Hamiltonian without gravity for a specific lattice depth is considered. The experimental result shows that there is almost no excitation into higher excited states during population transfer from the ground to the first excited state, even when this process is affected by gravity and inhomogeneous broadening in reality. By comparing all the techniques, the GRAPE technique is found to be the best in terms of increasing population transfer into the first excited state while reducing excitation into higher excited states. On the other hand, the ARP technique creates the highest normalized population inversion, a ratio of the difference to the sum of the ground and the first excited state populations.

The matching of colours on dyed fabric is an important task in the textile industry. The current method is based on the matching the visible reflectance spectrum to standard spectral libraries. In this study, the amount of dye on various wool and wool-blend fabric was measured using vibrational-spectroscopic techniques. FT-IR PAS and FT-Raman spectroscopy was used to analyse the following set of samples: woollen fabrics (supplied by CSIRO- Geelong, Australia), dyed with Lanasol dyes (Red 6G, Blue 3G and Yellow 4G) and wool/polyester fabrics (supplied by Ceiba-Geigy, Switzerland), dyed with Forosyn dyes (grey, yellow, green, brown, orange, red). A minimum of six spectra was recorded for each sample. The spectra recorded were consistent with those reported previously. FT-IR PA spectral data were block normalised with Y-mean centring and examined using Principle Component Analysis (PCA) and Partial Least Squares (PLS). Although PCA separates the woollen fabrics dyed with a combination of two colours, it does not do equally well for samples dyed with three colours. The dyed wool/ polyester blend samples appeared in a totally random fashion on the PCA plot. The PLS analysis of PA spectra of various ratios of dyes on woollen fabrics as well as wool/polyester blend was found to be a viable procedure and should be investigated further, perhaps with a broader set of data. FT-Raman spectra were examined using PCA and PLS. The best pre treatment for FT-Raman spectral data was found to be normalising followed by Y-mean centring. The PCA plots demonstrate that woollen samples are separated according to the dye ratios and that the presence or absence of some of the peaks is influenced by individual dyes. For example, the presence of the peak at 1430cm 1 is inversely related to the presence of blue dye on the fabric. The PLS resulted in SEE and SEP values of around 1 and 2 respectively indicating that the prediction of the dye ratios have not been very successful and suggesting that there was some problem with the measured values of the calibration set. PCA plots of wool/polyester fabrics dyed with a single colour indicate that PC1 separates the samples according to how close the shades are together, while PC2 and PC3 separate samples according to their individual colours. PC4, although explaining only a small percentage of variance, suggests that the samples are not homogeneously dyed. PCA plots of the samples dyed with various combinations of the three main dyes display each cluster of samples in their right position on the colour card. Calculated SEE and SEP values (Yellow: ~0.30, ~0.55, Brown: ~0.30, ~0.79, Red: 0.16, 0.49 and Grey: ~0.2, ~0.40, respectively) indicate that FT-Raman spectroscopy and chemometrics may offer promising methods for measuring the ratio of various dyes on wool/polyester fabrics. FT-Raman spectroscopy and chemometrics were also used to investigate the change in the ratio of dyes on UV-treated dyed woollen samples. Samples were weathered for 7 and 21 days, using accelerated weathering instrument. The substrate subtracted spectral data were normalised to 100% substrate of the first derivative (9 points and 7 degrees) followed by double centring of the matrix in the spectral region of 1500-500cm-1. PCA effectively separated non-irradiated from the irradiated sample but did not separate the irradiated samples further according to the number of days of irradiation. The pre-treatment used for PLS was first derivative of substrate subtracted spectral data normalised to 100% substrate, and then Y-mean centred. PLS failed to predict the ratio of the irradiated dyes very well. This may be because degradation products are not modelled by PLS or because the total amount of dye has reduced without changing the dye ratios.

Thesis (Ph. D.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 143-150). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 192-196).

Thesis (Ph.D.) -- University of Rhode Island, 2007 / Typescript. Includes bibliographical references (leaves 118-122).

Thesis (Ph. D.)--University of Oregon, 2001. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 146-152). Also available for download via the World Wide Web; free to University of Oregon users.