In this thesis we have investigated permutation and monomial progenitors of the form p^*n:N (p=2,3,5,...) and p^*n:_m N (p=3,5,7,...) respectively. We have discovered new symmetric presentations of several finite nonabelian simple groups including linear groups, unitary groups, orthogonal groups, and sporadic groups. We have constructed interesting groups found using the technique of double coset enumeration and found the isomorphic types of the numerous groups that appeared as homorphic images. These include the sympletic group, S_4(5) and the Janko groups, J_2 and J_1 which were found using a variety of different control groups over finite fields.

Abstract A progenitor developed by Robert T. Curtis is a type of infinite groups formed by the semi-direct product of a free group m∗n and a transitive permutation group of degree n. To produce finite homomorphic images we had to add relations to the progenitor of the form 2∗n : N. In this thesis we have investigated several permutations progenitors and monomials, 2∗12 : S4, 2∗12 : S4 × 2, 2∗13 : (13 : 4), 2∗30 : ((2• : 3) : 5), 2∗13 :13,2∗13 :(13:2),2∗13 :(13:S3),53∗2 :m (13:4),7∗8 :m (32 :8),and 53∗4 :m (13 : 4). We have discovered that the permutations progenitors produced the following finite homomorphic images, we have found P GL(2, 13), U3 (4) : 2, 2 × Sz (8), PSL(2,7), PGL(2,27), PSL(2,8), PSL(3,3), 4•S4(5), PSL2(53), and 13 : PGL2(53) as homomorphic images of this progenitors. We will construct double coset enumeration for the homomorphic images, 2 × Sz (8) over (13 : 4) Suzuki twisted group, P GL(2, 13) over S4,and PSL(2,7) over S4 and Maximal subgroups of 2×PGL(2,27) over 2•(13 : 2), P SL(2, 8) over (9 : 2), and P SL(3, 3) over (13 : 3). We will also give our techniques of finding finite homomorphic images and their isomorphism images.

This work concerns some synthetic processes and basic properties of layered double hydroxides (LDHs). A series of LDHs, a family of newly developed materials found to have many potential uses in industry, were investigated in relating to the origin of life on early Earth. In this work, I successfully intercalated some inorganic as well as organic species. Ammonium, accompanied with ferrocyanide ion, can enter the layered space. It was found there were two kin go f intercalated ferrocyanide species: one is that exchanged with anions and became a part of layered double hydroxide, while the other is suggested to be related to ammonium ferrocyanide neutral species. Formaldehyde, ethanolamine and formate can also be involved into LDHs. To improve the crystallinity, homogeneous precipitation method, which used Urea and Hexamine, was employed. The results reveal the success in the case by Urea but not in that by Hexamine. Annealing could also be used for this purpose. However, it needs to be preocessed in its mother liquor; no improvement on the crystallinity if the material has been washed before annealing.

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De la finance à la climatologie, en passant par les processus industriels, nombreux sont les domaines où on rencontre des séries temporelles. L'analyse, la modélisation et la prédiction de séries temporelles constituent aujourd'hui encore des défis, sur le plan scientifique tout comme dans ces nombreux domaines d'applications. En alternative aux modèles linéaires, les modèles non linéaires sont utilisés ici pour l'analyse, la modélisation et la prédiction de séries temporelles. Les modèles non linéaires sont potentiellement plus performants que les modèles linéaires, mais les questions de sélection de structure de modèle, de prédiction à long terme ou de construction des régresseurs sont plus complexes à résoudre dans le cadre non linéaire. Les paramètres de structure de certains modèles et des méthodes de sélection de structure sont d'abord décrits. La sélection de structure par FastBootrap est complétée par un test statistique qui constitue un argument théorique en faveur de l'approximation par régression linéaire du terme d'optimisme du Bootstrap. La Double Quantification Vectorielle (DQV), modèle de prédiction à long terme de séries temporelles, est introduite. La détermination des paramètres est détaillée, pour des séries scalaires et pour des séries multidimensionnelles auxquelles la DQV peut aisément être appliquée. La stabilité de la DQV en prédiction à long terme est établie théoriquement. Les capacités de la méthode sont illustrées sur divers exemples, en prédiction à court terme, à long terme, en scalaire et en multidimensionnel. La construction du régresseur est abordée lors de l'étude du caractère significatif de l'application des méthodes de clustering à des régresseurs. Une méthodologie de comparaison entre reconstructions de l'espace de phase de séries temporelles est décrite et appliquée sur plusieurs séries. Les résultats obtenus illustrent l'importance du délai dans la construction de régresseurs et permettent de prendre position dans un débat scientifique en cours : l'application des méthodes de clustering à des régresseurs a un sens. La construction du régresseur avec sélection d'un délai unique est alors généralisée au cas de plusieurs délais. Des généralisations des critères d'autocorrélation et d'information mutuelle à plus de deux variables sont proposées. Le critère géométrique de Distance à la Diagonale est également introduit. Tous ces critères de sélection de plusieurs délais sont comparés expérimentalement.

Built-up steel I-girders are very commonly used in bridge construction. Their spans are typically very long, and they are susceptible to lateral torsional buckling if not enough lateral support is provided. This thesis includes guidelines for preventing lateral torsional buckling of steel I-girders under dead and wind load, accompanied with finite element analysis of double girder systems. The first portion includes capacity envelopes for single girders with single and double symmetric cross sections under various loading conditions and boundary conditions for double and single symmetric cross sections with double girders subjected to dead loads only. The second portion is dedicated to finite element analysis of double girders. Buckling analyses have been conducted on single symmetric double girders to verify their capacity equations and investigate the behavior of double girders subjected to wind load. The analyses focus on the weak axis bending of the double girder system as a whole and an evaluation of whether buckling of cross-bracing is an issue when lateral loads are present.

Convection set up in a fluid due to the presence of two components of differing diffusivities is known as double diffusive convection. Double diffusive convection is observed in nature, in oceans, in the formation of certain columnar rock structures and in stellar interiors. The major engineering applications of double diffusive convection are in the fields metallurgy and alloy solidification in casting processes. The two components may be any two substances which affect the density of the fluid, heat and salt being the pair found most commonly in nature. Depending upon the initial stratifications of the two components, double diffusive convection can be set up in either the diffusive mode or the finger mode. In this thesis, the linear stability of a double diffusive system prone to finger instability has been studied in the presence of temporally varying non-linear background profiles of temperature and salinity. The motivation for the present study is to bridge the gap between existing theories, which mainly concentrate on linear background profiles independent of time, on the one hand and experiments and numerical simulations, which have time dependent step-like non-linear background profiles, on the other. The general stability characteristics of a double diffusive system with step-like background profiles have been studied using the standard normal mode method. The background temperature and salinity profiles are assumed to follow the hyperbolic tangent function, since it has a step-like character. The sharpness of the step can be altered by changing a suitable parameter in the hyperbolic tangent function. It is found that changing the degree of non-linearity of the background profile of one of the components keeping the background profile of the other component linear affects the growth rate, Wave number and the form of the disturbances. In general, increasing the degree of nonlinearity of background salinity profile makes the system more unstable and results in a reduction in the vertical extent of the disturbances. On the other hand, increasing the degree of non-linearity of the background temperature profile with the salinity profile kept linear results in a reduction in the growth rate and increase in the wave number. The form of the disturbance may change due to enhanced modal competition between the gravest odd and even modes in this case. The method of normal modes inherently assumes that the background profiles of temperature and salinity are independent of time and hence, it cannot be used for studying the stability of systems with time varying background profiles. A pseudo-similarity method has been used to handle such background profiles. Initial steps of temperature and salinity diffuse according to the error function form, and hence, the case of error function background profiles has been studied in detail. Taking into account the time-dependence of background profiles has been shown to significantly change the wave number and the incipient flux ratio. The dependence of the critical wave number (kc) on the thermal Rayleigh number (RaT ) can be determined analytically and is found to change from kc ~ Ra T1/4 for linear background profiles to kc ~ Ra T1/3 for error function profiles. The region of instability in the Rp (density stability ratio) space is found to increase from 1 ≤ R ρ ≤ r−1 for linear background profiles to 1 ≤ Rρ < r−3/2 for error function background profiles, where T denotes the ratio of the diffusivity of the slower diffusing component to that of the faster diffusing one. A parametric study covering a wide range of parameter values has been carried out to determine the effect of the parameters density stability ratio (Rp), diffusivity ratio (ρ ) and Prandtl number (Pr) on the onset time, critical wavenumber and the incipient flux ratio. The wide range of governing parameters covered here is beyond the scope of experimental and numerical studies. Such a wide range can be covered by theoretical approaches alone. It has been shown that the time of onset of convection determines the thicknesses of the temperature and salinity boundary layers, which in turn determine the width of salt fingers. Finally, the theoretical predictions of salt finger widths have been shown to be in agreement with the results of two dimensional numerical simulations of thermohaline system.

Protected DHA units, known as dioxanones, are interesting compound which can be used as the building blocks for synthesis of polyoxygenated natural products. The direct aldol reaction is employed for converting of those inexpensive starting materials into enantioenriched products of complexed structures. The stereocontrol in the first aldol reaction is achieved by using organocatalysis. Second aldol reaction is conducted by lithium enolate chemistry leading to anticisanti aldols as a major isomer. On the other hand boron chemistry provides antitransanti products. This strategy is used for synthesis of higher sugars.

During the Second World War, more than 22,000 Japanese Canadians were interned to various locations throughout Canada. While more than 60 years have passed since these events, there remains limited research on the impact that this event had on this group of people. Using McCubbin and Patterson’s (1983) Double ABCX model of family stress and adaptation as a framework, this study used historical narratives of 69 Japanese Canadians to gain insight into a) how Japanese Canadians coped with the challenges associated with their internment, and b) what resources they used during this same time period. The analysis of the coping strategies was done using a modified version of existing measures of coping strategies (Folkman, Lazarus, Dunkel-Schetter, DeLongis, & Gruen, 1986; Suedfeld, Krell, Wiebe, & Steel, 1997), and the analysis of resources was done using an adjusted version of Rettig’s (1995) and Tucker and Rice’s (1985) resource classification list. There were no statistically significant differences between Japanese Canadian men and women in their coping strategy use, but that there were differences between the Issei (first generation) and Nisei (second generation). The Issei used Self Control, Positive Reappraisal, and Denail more than the Nisei, while the Nisei used Seeking Social Support more than the Issei. A strong relationship between coping and resources was found; a relationship that has often been assumed, but never tested. The findings from this study also provided additional support for the usefulness of using both narratives and the Double ABCX model in research.