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Québec Université Laval, Bibliothèque 2018

Disons que je me cogne l’orteil à l’instant. Selon le physicalisme, il est possible d’expliquer l’ensemble de ce qui se produit alors de façon purement physique. Ultimement, il s’agit de certaines interactions entre les particules de mon orteil et de celles du mur, qui mènent à des interactions dans mon système nerveux, qui mènent à d’autres interactions dans mon appareil vocal, de façon à ce qu’on entende « Aïe! ». Je crois qu’il manque quelque chose d’important à cette histoire, en l’occurrence l’effet que cela fait de se cogner l’orteil : ma douleur phénoménale à l’orteil. Plus généralement, l’ontologie de la physique n’est pas suffisante pour rendre compte de la conscience phénoménale. La question est de savoir par quoi la remplacer. Dans ce mémoire, j’explore la possibilité d’une ontologie qui ne serait pas physicaliste, mais qui serait quand même naturaliste, c’est-à-dire qu’elle reposerait quand même sur les sciences naturelles. Après tout, la science n’a pas à se limiter à l’ontologie de la physique actuelle. Pour mener à bien cette exploration, je comparerai les deux possibilités qui me semblent les plus plausibles, c’est-à-dire le naturalisme transcendantal de Colin McGinn et le dualisme naturaliste de David Chalmers. McGinn affirme qu’il existe une réponse naturaliste au problème corps-esprit, mais qu’elle n’est pas cognitivement accessible à l’humain, de la même façon que la solution au problème de la gravité n’est pas accessible à l’écureuil par exemple. Chalmers croit au contraire qu’il est bien possible de répondre au problème, à condition d’introduire la conscience phénoménale dans notre ontologie comme une nouvelle entité, comme Newton l’avait fait avec la gravité. J’expliquerai qu’un compromis est en réalité possible entre McGinn et Chalmers. La position de Chalmers est menacée par des paradoxes et des problèmes qui ne seront ultimement réglés qu’en concédant beaucoup de terrain à McGinn.

Nonlinear shallow shell equations are derived for a thin shell of revolution having the shape of a narrow segment of a toroidal shell centered at the equator. The equations are derived by considering a cylindrical shell, described by nonlinear Donnell theory, with an initial radial deformation. Linear buckling equations are obtained by perturbing the nonlinear shell equations. The buckling equations are solved for the case of a simple supported equatorial segment of a spherical shell loaded in the axial direction by its own weight. Plots are presented which compare a critical thickness parameter with the results of an elementary approach. The elementary approach assumes that the shell will buckle if the maximum compressive stress is greater than the critical compressive stress for a complete sphere loaded by uniform external pressure. / M.S.

M.S.

Ovariole development and termination of diapause in the white pine weevil were studied by dissecting weevils at various intervals throughout the winter. Old-generation adults brought into the laboratory November produced viable eggs within 5 days. New generation adults brought into the laboratory on November 4 produced viable eggs during November. Viable eggs were deposited by other new-generation adults after 10 to 15 day. at room temperature in winter. On each of the 3 collection date studied, new generation adult produced viable eggs without copulating after collection from hibernation indicating that capulation occurs in the fall. There was no evidence of progressive ovariole development throughout the winter. New generation adults which were isolated as soon as they emerged from the shoots and maintained at constant room temperature had poorly developed ovarioles by November 20 and produced no eggs. Weevil flight and dispersal through a white pine plantation was studied by releasing 409 marked weevils at a central point within a l431-tree plantation and checking every tree at 5-day intervals. Weevils flew readily at the time of re1ease. Marked weevils were recorded throughout the plantation. which extended as far as 330 feet from the release point. A few weevils were observed on scattered white pines 200-300 yards from the release point beyond a hardwood barrier. Total numbers of weevils present on the leaders increased from April 26 to May 5, after which numbers steadily decreased. By June 15, only 20 weevils were observed on the leaders. / Ph. D.

The preparation of 2-(3-chloro-l-naphthylmethyl)bromobenzene was achieved by the cross-condensation reaction of 3-chloro-l-naphthylmagnesium bromide and 2-bromobenzyl bromide, as well as by the reaction of this Grignard reagent with 2-bromobenzaldehyde, followed by reduction of the resulting carbinol with lithium aluminum hydride and aluminum chloride. It was found that 2-bromophenyl-1-(3-chloronaphthyl)carbinol thermally decomposed into the corresponding methylene compound and ketone. A study of the thermally induced reaction of the carbinol was made, and the products were quantitatively analyzed by means of gas chromatography. It was concluded that the anomalous products of the reaction of an aryl Grignard reagent with a benzaldehyde were actually p~duced by the thennal disproportionation of the resulting carbinols during the distillation step. The keto-acid, 2-(3-chloro-l-naphthylmethyl)- 2’-carboxybenzophenone was prepared by the inverseaddition of the Grignard reagent of 2-(3-chloro-l-naphthylmethyl)bromobenzene to phthalic anhydride. Cyclization of this keto-acid with an acetic and hydrobromic acid mixture gave 6-chloro-7-(2-carboxyphenyl)benz[a]anthracene. Methyl ester derivatives were prepared from both this acid and the precursor keto-acid. The cyclodehydration of either 2-(3-chloro-l-naphthylmethyl)-2'-carboxybenzophenone or 6-chloro-7-(2-carboxyphenyl)benz[a]anthracene with polyphosphoric acid gave 14-chlorodibenzo[hi,l]chrysen-9-one.· Treatment of this ketone with lithium aluminum hydride and aluminum chloride gave the reduction derivative, 14-chloro-9H-dibenzo[hi,l]chrysene. The unequivocal synthesis of dibenzo[hi,l]- chrysen-9-one was achieved by the dehalogenation of 14-chlorodibenzo[hi,l]chrysen-9-one with 10% palladiumcharcoal catalyst and hydrazine. The dehalogenated product was shown to be identical to the compound produced from the cyclodehydration of 7-(2-carboxyphenyl)benz[a]anthracene. The ketone, 2-(3-chloro-l-naphthylmethyl)benzophenone was prepared by the inverse-addition of the Grignard reagent of 2-(3-chloro-l-naphthylmethyl)- bromobenzene to benzoyl chloride. It was found that a small amount (16%) of 6-chloro-7-phenylbenz[a]-anthracene was formed during the distillation of the precursor ketone. The cyclodehydration of this ketone failed when various standard cyclizing media were employed, and the reason for this is discussed. Cyclization attempts with polyphosphoric acid or alumina gave dibenzo[a,l]pyrene as the only identifiable product. This unusual reaction obviously involves a rearrangement. A study was made and a mechanism for this reaction was postulated which is consistent with the experimental observations. The ketone, 2-(3-cyano-l-naphthylmethyl)benzophenone was prepared by the reaction of the corresponding chloro ketone with cuprous cyanide in N-methylpyrrolidone. 6-Cyano-7-phenylbenz[a]- anthracene was also produced in small quantity in this reaction as a consequence of the presence of the corresponding chloro compound in the ketone prior to reaction. Naphtho[3, 2, l-fg]naphthacen-9-one was prepared by the treatment of 6-cyano-7-phenylbenz[a]anthracene with a hydrobromic and acetic acid mixture at 180°, and also by the treatment of the precursor cyano ketone with polyphosphoric acid. The novel use of polyphosphoric acid in cyano group hydrolysis is discussed. Phenalo[2, 3, 4, 5-defg]naphthacene-4, 8-quinone was prepared by the treatment of 6-cyano-7-(2-carboxyphenyl)benz[a]anthracene with a hydrobromic and acetic acid mixture at 180°. An attempted procedure for the. preparation of this quinone involved the oxidation of 7-(2,6-dimethylphenyl)benz[a]anthracene to the corresponding diacid with aqueous sodium dichromate. Unfortunately this new method of oxidation failed in this case. The partial resolution of 7-(2-carboxyphenyl)-benz[a]anthracene was achieved with the use of brucine. Only one optically active isomer was obtained, and this was racemized by treatment with boiling ethanol. An empirical rule used to quantitatively determine the resistance of optically active biphenyls to racemization was applied to this acid, and the experimental observations were supported. During the course of this investigation, sixteen new compounds were prepared and were all properly characterized, except 6-cyano-7-(2-carboxyphenyl)- benz[a]anthracene, which did not give acceptable analytical data. The reason for this is discussed. Infrared and ultraviolet spectra of all new compounds were recorded. Infrared spectral observations were made which gave further support to the assigned structures of the isomeric compounds naphtho[3,2,l-fg]- naphthacen-9-one and dibenzo[hi,l]chrysen-9-one. / Doctor of Philosophy

An experiment has been performed which establishes the capability of the reactor at V.P.I. to provide a satisfactory neutron supply for neutron radiography. Several different specimens including low Z materials and heavier materials such as iron have been used as test objects. The effects of alternate methods of obtaining the radiographs and of the different experimental parameters have been studied. Quantitative investigations were made of the effects of voids of different depths in varying thicknesses of three test specimens which consisted of graphite, bakelite, and plexiglass. The results of these studies showed that it would be practical to detect voids of as little as 1/32 of an inch at depths of up to one inch in the test specimens. It is felt that the research performed in this experiment adequately demonstrated the usefulness of neutron radiographic methods in non-destructive testing and the capability of the V.P.I. reactor facility for this technique. / Master of Science