McGill University Thèses et mémoires publiés en 1991

The miscibility of poly(vinyl pyrrolidone) PVP with copolymers of vinyl butyral and vinyl alcohol, containing 11% and 19% by weight of vinyl alcohol, has been investigated. To examine how the state of miscibility of these blends varies with the vinyl alcohol content of the copolymers, differential scanning calorimetry(DSC) and solid-state NMR methods were employed. PVP was found to form miscible blends with poly(vinyl butyral) PVB, containing 11wt% of vinyl alcohol, up to a weight ratio of 40/60(PVP/PVB11). At higher PVP loading, phase separated blends were obtained. In contrast, poly(vinyl butyral) containing 19wt% vinyl alcohol units was found to be miscible …  Read more

The efficacy of a lucid dream induction (LDI) technique was evaluated. The results indicated that, among previously non-lucid dreamers, a significantly greater proportion of subjects who had access to the technique reported a lucid dream. This group also reported more lucid dreams overall than the control group. For prior lucid dreamers, the technique was found to increase the number of such dreams reported, relative to baseline levels. The LDI technique was incorporated into a treatment procedure for recurrent nightmares. This treatment method was found to be effective in three individuals, although not all of them achieved a lucid dream state. …  Read more

The primitive New Zealand frog Leiopelma hochstetteri shows exceptional karyotypic variation. On the North Island, females carry univalent W chromosome and both sexes have 0 to 15 supernumerary chromosomes. Frogs from Great Barrier Island have a conventional 2n = 22 karyotype, with no sex chromosome differentiation in C-banded mitotic chromosomes. However, the lampbrush chromosomes of a Great Barrier Island female show evidence of heterogamety. This suggests that presumed ancestral female heterogamety has persisted on Great Barrier Island and given rise to a WZZ-female/ZZ-male sex chromosome system on the North Island. A repeated sequence, Lh1, varies greatly within populations in copy …  Read more

A practical geometric optics method for derivation of the optical forces from light rays was described. By this method, the forces from a G.P.W. (Gaussian Plane Wave) and a general TEM$ sb infty$ laser beam were calculated and studied. For a G.P.W. beam, there were two forces which acted on small particles located inside the electromagnetic field; one, called the scattering force, directed in the beam propagation direction, pushed particles axially. The other, called the gradient force, due to the non-uniformity of the electromagnetic field, acted like an optical well and confined the particles of the beam axis. The forces …  Read more

Electrochemical methods have been used to measure the solubility and diffusivity of hydrogen in amorphous $Ni sb{60}Zr sb{40}$ over a wide range of hydrogen concentrations. It is found that Sievert's law is not obeyed and that the concentration of hydrogen in the metallic glass varies as $P sp{1/4}$, P being the pressure of hydrogen. In the concentration range of hydrogen measured, the diffusion constant of hydrogen increases by more than a factor of ten. A Gaussian distribution of hydrogen binding energy was used to explain the concentration dependence of chemical potential. A possible explanation to the concentration dependence of diffusion …  Read more

After a wild-type isolate of Epicoccum purpurascens was exposed to shortwave ultraviolet light, several new strains were recovered which were improved in sporulation, fungicide tolerance, and performance in suppression of white mold caused by Sclerotinia sclerotiorum. The efficacy of E. purpurascens in controlling white mold of snap bean (Phaseolus vulgaris) was assessed in greenhouse and field trials. White mold was significantly reduced in both greenhouse and field trials when 2-4 sprays of E. purpurascens conidial suspensions (in 1% malt extract) were sprayed onto the plant surface during the flowering period. Germination of E. purpurascens conidia on senescent petals was greater …  Read more

This thesis presents the development of an intelligent CAD system (ICADS) for DC machines. This system was implemented on a PC using Common Lisp provided by Gold Works II and connected with a Sun Workstation working under the Unix system for file transfer. Both frame-based and rule-based knowledge representation techniques have been used to capture the knowledge about the design of electric machines. The system has its own inference engine specially designed to handle both decision making and numerical computation. Forward-chain reasoning and procedural attachment were used to construct this inference engine. The knowledge base management system provides a user …  Read more

The direct causticization of kraft black liquor is investigated both thermodynamically and experimentally. A comprehensive thermodynamic analysis is performed to identify suitable causticizing metal oxides and process configurations. TiO$ sb2$ is found to be the only metal oxide which can be used for kraft black liquor recovery. Of two possible process configurations, the two-step combustion and reduction process is selected for further experimental study in the present work. The kinetics of the direct causticization reaction between Na$ sb2$CO$ sb3$ and TiO$ sb2$ in a mixture with Na$ sb2$SO$ sb4$ are studied in a tube furnace from 750 to 925$ sp …  Read more