Deuterated variations of poIy(lauryl methacrylate) (PLMA) have been synthesised, this involved the initial synthesis of the monomer (LMA). This was achieved by a transesterification reaction between methyl methacrylate and lauryl alcohol using either hydrogenous or deuterated materials depending on which part of the resulting LMA monomer was to be deuterated. The physical properties of PLMA and LMA spread monolayers have been investigated using surface pressure - area isotherms and surface quasi - elastic light scattering (SQELS). The isotherms for PLMA show that the thermodynamic state of the polymer is poorer than theta conditions and no variation occurs with changes in temperature. LMA shows a drastic change in the nature of the isotherm as the temperature is varied. This has been attributed to the formation of lenses and the variation caused by temperature is due to a change in the rate of migration of the LMA molecules. The SQELS results show that the PLMA monolayer displays the characteristics of a Voigt solid model and shows no viscous relaxation processes. SQELS has also been used to demonstrate the biphasic nature of the monolayer at low surface concentrations, the size of the polymer 'islands' has been estimated to be in the range of 5 to 20mm. SQELS from LMA monolayers showed that the two higher surface concentrations gradually converted into the same state as that obtained for the low

No description available.

No description available.

QC 351 A7 no. 74 / Measurements of the scattering of reflected light as a function of angular separation from the specular direction were made on aluminum-coated flat glass samples with surface roughnesses ranging from 1.0 nm to 70 nm rms deviation from the mean surface. Small -angle scatter (measured between 0.33° and 1° away from the specular direction) was investigated using light that had passed through a narrow slit; a measure of the scattering magnitude was provided by comparison of the far -field diffraction patterns produced by the slit, reflected from the samples and without the samples in place. The slit used to produce the diffraction patterns was optically processed to be smooth enough so that without the sample in place the minima of the diffraction pattern would be well defined and of lower magnitude than the scattered flux produced when the samples were in place. By considering the effects of the scanning aperture, it was determined that the measured magnitude of the minima agreed with those predicted by the use of Kirchhoff theory to within a factor of three. Comparison of small-and large-angle scatter measurements made on the same set of samples indicated that a transition region between the two types of scatter may exist in the region of 1° to 5° away from the specular direction. Because separate instruments were used for the small-and large-angle measurements, the results are expressed in terms independent of the measuring instrument's geometry. The measured results were compared to a theory in which the choice of the scatter function, and by implication the autocorrelation function, could be arbitrary. This comparison revealed that the choice of the hyperbolic secant function, rather than a Gaussian function, provided a good fit to the small-angle data. By fitting a curve to the small -angle data, it was possible to estimate the autocorrelation length of the surface roughness as well as the peak value of the scattering profile. The scatter measurements for the smoothest sample ranged from approximately 3 X 10' per µsr near the specular direction to 10 -13 per µsr at wide angles. For the roughest sample, the range was from 3 X 10-4 per µsr to 10-10 per µsr.

No description available.

No description available.

No description available.

Abstract The mathematical analysis of scattering theory has been a major area of interest in mathematics and physics research since the latter half of the twentieth century. The aim of this work is to examine, in a functional analytic setting, properties of the differential operator L and solutions involved for scattering on the line −∞ < x < ∞. The characterisation of the spectrum of L will provide insight into the physical interpretation of the problem. The study of scattering theory will proceed with the major results in the field being presented with particular focus on reflectionless scattering. Attention is then directed to the inverse reflectionless case. We look at scattering on the line with a matrix transfer condition at the origin in addition an overview of the inverse case is presented.

by Hui Yuk Tak. / Bibliography: leaf 41 / Thesis (M.Ph.) -- Chinese University of Hong Kong, 1984

by Li To-sing. / Bibliography: leaves 113-116 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1986