Physics / M. Sc. (Physics)

A two-dimensional integrodi erential equation resulting from the use of potential harmonics expansion in the many-body Schr odinger equation is used to study ground-state properties of selected few-body nuclear systems. The equation takes into account twobody correlations in the system and is applicable to few- and many-body systems. The formulation of the equation involves the use of the Jacobi coordinates to de ne relevant global coordinates as well as the elimination of center-of-mass dependence. The form of the equation does not depend on the size of the system. Therefore, only the interaction potential is required as input. Di erent nucleon-nucleon potentials and hyperon-nucleon potentials are employed to construct the Hamiltonian of the systems. The results obtained are in good agreement with those obtained using other methods. / Physics

Physics / M. Sc. (Physics)

A two-dimensional integrodi erential equation resulting from the use of potential harmonics expansion in the many-body Schr odinger equation is used to study ground-state properties of selected few-body nuclear systems. The equation takes into account twobody correlations in the system and is applicable to few- and many-body systems. The formulation of the equation involves the use of the Jacobi coordinates to de ne relevant global coordinates as well as the elimination of center-of-mass dependence. The form of the equation does not depend on the size of the system. Therefore, only the interaction potential is required as input. Di erent nucleon-nucleon potentials and hyperon-nucleon potentials are employed to construct the Hamiltonian of the systems. The results obtained are in good agreement with those obtained using other methods. / Physics / M.Sc. (Physics)

Au quotidien, le réflexe de classifier est omniprésent et inconscient. Par exemple dans le processus de prise de décision où face à un élément (un objet, un événement, une personne) nous allons instinctivement chercher à rapprocher cet élément d'autres similaires afin d'adapter nos choix et nos comportements. Ce rangement dans telle ou telle catégorie repose sur les expériences passées et les caractéristiques de l'élément. Plus les expériences seront nombreuses et les caractéristiques détaillées, plus fine et pertinente sera la décision. Il en est de même lorsqu'il nous faut catégoriser un document en fonction de son contenu. Par exemple détecter s'il s'agit d'un conte pour enfants ou d'un traité de philosophie. Ce traitement est bien sûr d'autant plus efficace si nous possédons un grand nombre d'ouvrages de ces deux catégories et que l'ouvrage à classifier possède un nombre important de mots.Dans ce manuscrit nous nous intéressons à la problématique de la prise de décision lorsque justement nous disposons de peu de documents d'apprentissage et que le document possède un nombre de mots limité. Nous proposons pour cela une nouvelle approche qui repose sur de nouvelles pondérations. Elle nous permet de déterminer avec précision l'importance à accorder aux mots composant le document.Afin d'optimiser les traitements, nous proposons une approche paramétrable. Cinq paramètres rendent notre approche adaptable, quel que soit le problème de classification donné. De très nombreuses expérimentations ont été menées sur différents types de documents, dans différentes langues et dans différentes configurations. Selon les corpus, elles mettent en évidence que notre proposition nous permet d'obtenir des résultats supérieurs en comparaison avec les meilleures approches de la littérature pour traiter les problématiques de petits volumes.L'utilisation de paramètres introduit bien sur une complexité supplémentaire puisqu'il faut alors déterminer les valeurs optimales. Détecter les meilleurs paramètres et les meilleurs algorithmes est une tâche compliquée dont la difficulté est théorisée au travers du théorème du No-Free-Lunch. Nous traitons cette seconde problématique en proposant une nouvelle approche de méta-classification reposant sur les notions de distances et de similarités sémantiques. Plus précisément nous proposons de nouveaux méta-descripteurs adaptés dans un contexte de classification de documents. Cette approche originale nous permet d'obtenir des résultats similaires aux meilleures approches de la littérature tout en offrant des qualités supplémentaires.Pour conclure, les travaux présentés dans ce manuscrit ont fait l'objet de diverses implémentations techniques, une dans le logiciel Weka, une dans un prototype industriel et enfin une troisième dans le logiciel de la société ayant financé ces travaux. / Every day, classification is omnipresent and unconscious. For example in the process of decision when faced with something (an object, an event, a person), we will instinctively think of similar elements in order to adapt our choices and behaviors. This storage in a particular category is based on past experiences and characteristics of the element. The largest and the most accurate will be experiments, the most relevant will be the decision. It is the same when we need to categorize a document based on its content. For example detect if there is a children's story or a philosophical treatise. This treatment is of course more effective if we have a large number of works of these two categories and if books had a large number of words. In this thesis we address the problem of decision making precisely when we have few learning documents and when the documents had a limited number of words. For this we propose a new approach based on new weights. It enables us to accurately determine the weight to be given to the words which compose the document.To optimize treatment, we propose a configurable approach. Five parameters make our adaptable approach, regardless of the classification given problem. Numerous experiments have been conducted on various types of documents in different languages and in different configurations. According to the corpus, they highlight that our proposal allows us to achieve superior results in comparison with the best approaches in the literature to address the problems of small dataset. The use of parameters adds complexity since it is then necessary to determine optimitales values. Detect the best settings and best algorithms is a complicated task whose difficulty is theorized through the theorem of No-Free-Lunch. We treat this second problem by proposing a new meta-classification approach based on the concepts of distance and semantic similarities. Specifically we propose new meta-features to deal in the context of classification of documents. This original approach allows us to achieve similar results with the best approaches to literature while providing additional features. In conclusion, the work presented in this manuscript has been integrated into various technical implementations, one in the Weka software, one in a industrial prototype and a third in the product of the company that funded this work.

Despite the increase in popularity of handheld devices, text entry on such devices is becoming more difficult due to reduced form factors that limit display size, input modes, and interaction techniques. In an effort to circumvent these issues, research has found that five-key methods are effective for text entry on devices such as in-car navigation systems, television and gaming controllers, wrist watches, and other small devices. Five-key text entry methods use four directional keys to move a selector over an on-screen keyboard and an Enter key for selection. Although other researchers have described five-key character layouts using alphabetical order and predictive layouts based on digraph frequencies, there is considerable latitude in designing the rest of a comprehensive on-screen keyboard. Furthermore, it might be possible to capitalize on the relative strengths of the alphabetic and predictive layouts by combining them in a hybrid layout. Thus, this research examines the design of alternative keyboard layouts for five-key text entry techniques. Three keyboard layouts (Alphabetical, Predictive, and Hybrid) were selected to represent standard and less familiar arrangements. The analysis centered on a series of controlled experiments conducted on a research platform designed by the author. In this work, when the immediate usability of three alternative keyboard layouts for supporting five-key text entry was investigated, results indicated no statistically significant differences in performance across the tested keyboards. Furthermore, experimental results show that following immediate usability, but still at the onset of learning, there was no overall difference in performance among the three keyboard layouts across four text types. However, the Alphabetical keyboard surpassed both the Predictive and Hybrid keyboards in text entry speed in typing Web addresses. The nonstandard keyboards performed superior to the Alphabetical keyboards in typing Words/Spaces and Sentences, but performed no better in typing Address strings than the Alphabetical. Use of mixed effects modeling suggested that the longitudinal data was best fitted by a quadratic model. Text entry performance on all three layouts improved as a function of practice, demonstrating that participants could learn the unfamiliar layouts to complete text entry tasks. Overall, there was no indication that use of nonstandard layouts impedes performance. In fact, trend in time data suggests that the learning rates were greater for the nonstandard keyboards over the standard layout. Overall, participants preferred the Hybrid layout. In summary, this dissertation focused on creating and validating novel and effective five-key text entry techniques for constrained devices.

The pore diameter of a catalyst support controls the diffusion of reactant molecules to the catalytic active sites; thus, affecting the rates and conversions of the hydrotreating reactions. Desirable textural properties of SBA-15 makes it a potential alternative to the conventionally used γ-Al2O3 support due to the fact that its pore size can be manipulated via controlling the synthesis parameters, while maintaining relatively high surface area. Larger pore diameter SBA-15 supports may facilitate the diffusion of bulky molecules as that of the asphaltenes present in the heavy petroleum fractions, making it a potential catalyst support for hydrotreating operations. Considering the very sour nature of Canadas bitumen with high sulfur contents in the range of 2-6 wt %, the appreciably high sulfur contents particularly present in Athabasca derived heavy gas oils (about 4 wt % sulfur), the rising demand for cleaner fuels, and also the increasing stringency on environmental standards, the need for novel and improved hydrotreating catalysts cannot be overemphasized. By varying the molar ratio of hexane to ammonium fluoride, the pore channels of SBA-15 could be varied. Controlling the pore diameter of these supports via micelle swelling facilitated the production of larger pore diameter SBA-15-supported catalysts. In this project, four mesoporous silica SBA-15 catalyst supports with pore diameters in the range of 5-20 nm were synthesized in the preliminary phase using hexane as the micelle swelling agent and subsequently utilized for the loading of 2 wt.% Fe and 15 wt.% W catalyst metals, respectively. The hexagonal mesoscopic structure of these materials were characterized using powder small-angle X-ray scattering (SAXS), N2 adsorption-desorption isotherms, TEM and SEM images. Powder XRD analysis evidenced inhomogeneous metal dispersion on the largest pore diameter catalyst. An optimum pore diameter of 10 nm was found for Cat-B and subsequently used to obtain the optimum Fe and W loadings required to achieve the best hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities. The optimum catalyst was found to be Cat-H with metal loadings of 3 wt.% Fe and 30 wt.% W. At these loadings and temperatures of 375°C, 388°C, and 400°C, HDS activities of 53.4%, 64.1%, and 73.3% with corresponding HDN activities of 21.9%, 26.2%, and 38.3%, respectively, were recorded. Catalytic performance evaluations conducted on equal mass loading using a reference commercial γ-Al2O3-supported FeW catalyst offered HDS activities of 69.3%, 80.4%, and 89.1%, with corresponding HDN activities of 16.4%, 32.4%, and 49.3% at the same temperatures studied. However, no significant changes in HDS and HDN activities were observed for similar evaluations on volume percent metals loading basis. Kinetic studies performed with the optimum FeW/SBA-15 catalyst suggested activation energies of 147.2 and 150.6 kJ/mol for HDS and HDN, respectively, by the Langmuir-Hinshelwoods model. Similar results were predicted by the Power Law and Multi-parameter models for HDS (129.6 and 126.7 kJ/mol, respectively), which does not conclusively make the latter model clearly stand out as the best. Data fitting by the Power Law suggested reaction orders of 2 and 1.5 for HDS and HDN, which seem to be consistent for the hydrotreatment of heavy gas oil. Finally, a long-term deactivation study spanning a period of 60 days time-on-stream showed the optimum catalyst to be stable under hydrotreating experiments conducted in a downward flow micro-trickle bed reactor at temperature, pressure, liquid hourly space velocity (LHSV), and gas/oil ratio of 375400˚C, 8.8 MPa, 1h-1, and 600 mL/mL (at STP), respectively.

The pore diameter of a catalyst support controls the diffusion of reactant molecules to the catalytic active sites; thus, affecting the rates and conversions of the hydrotreating reactions. Desirable textural properties of SBA-15 makes it a potential alternative to the conventionally used γ-Al2O3 support due to the fact that its pore size can be manipulated via controlling the synthesis parameters, while maintaining relatively high surface area. Larger pore diameter SBA-15 supports may facilitate the diffusion of bulky molecules as that of the asphaltenes present in the heavy petroleum fractions, making it a potential catalyst support for hydrotreating operations. Considering the very sour nature of Canadas bitumen with high sulfur contents in the range of 2-6 wt %, the appreciably high sulfur contents particularly present in Athabasca derived heavy gas oils (about 4 wt % sulfur), the rising demand for cleaner fuels, and also the increasing stringency on environmental standards, the need for novel and improved hydrotreating catalysts cannot be overemphasized. By varying the molar ratio of hexane to ammonium fluoride, the pore channels of SBA-15 could be varied. Controlling the pore diameter of these supports via micelle swelling facilitated the production of larger pore diameter SBA-15-supported catalysts. In this project, four mesoporous silica SBA-15 catalyst supports with pore diameters in the range of 5-20 nm were synthesized in the preliminary phase using hexane as the micelle swelling agent and subsequently utilized for the loading of 2 wt.% Fe and 15 wt.% W catalyst metals, respectively. The hexagonal mesoscopic structure of these materials were characterized using powder small-angle X-ray scattering (SAXS), N2 adsorption-desorption isotherms, TEM and SEM images. Powder XRD analysis evidenced inhomogeneous metal dispersion on the largest pore diameter catalyst. An optimum pore diameter of 10 nm was found for Cat-B and subsequently used to obtain the optimum Fe and W loadings required to achieve the best hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities. The optimum catalyst was found to be Cat-H with metal loadings of 3 wt.% Fe and 30 wt.% W. At these loadings and temperatures of 375°C, 388°C, and 400°C, HDS activities of 53.4%, 64.1%, and 73.3% with corresponding HDN activities of 21.9%, 26.2%, and 38.3%, respectively, were recorded. Catalytic performance evaluations conducted on equal mass loading using a reference commercial γ-Al2O3-supported FeW catalyst offered HDS activities of 69.3%, 80.4%, and 89.1%, with corresponding HDN activities of 16.4%, 32.4%, and 49.3% at the same temperatures studied. However, no significant changes in HDS and HDN activities were observed for similar evaluations on volume percent metals loading basis. Kinetic studies performed with the optimum FeW/SBA-15 catalyst suggested activation energies of 147.2 and 150.6 kJ/mol for HDS and HDN, respectively, by the Langmuir-Hinshelwoods model. Similar results were predicted by the Power Law and Multi-parameter models for HDS (129.6 and 126.7 kJ/mol, respectively), which does not conclusively make the latter model clearly stand out as the best. Data fitting by the Power Law suggested reaction orders of 2 and 1.5 for HDS and HDN, which seem to be consistent for the hydrotreatment of heavy gas oil. Finally, a long-term deactivation study spanning a period of 60 days time-on-stream showed the optimum catalyst to be stable under hydrotreating experiments conducted in a downward flow micro-trickle bed reactor at temperature, pressure, liquid hourly space velocity (LHSV), and gas/oil ratio of 375400˚C, 8.8 MPa, 1h-1, and 600 mL/mL (at STP), respectively.

<p>An experiment measuring the analyzing power A_y(&theta;) for neutron&ndash;helium-3 (<italic>n</italic>-<super>3</super>He) elastic scattering over broad angular distributions for a range of incident neutron energies from 1.60 to 5.54 MeV has been conducted at the Triangle Universities Nuclear Laboratory. These measurements represent an effort to resolve the long-standing discrepancy between experiment and theory in low-energy three-nucleon analyzing powers, through the evaluation of analyzing powers in the four-nucleon systems, which are expected to exhibit sensitivities not accessible with fewer nucleons. The present work is described in terms of the experimental setup and data reduction techniques; a comparison of the results with rigorous calculations using both nucleon-nucleon and, as recently has become available, three-nucleon potential models is presented. While a discrepancy between calculation and measurement was observed, at low energies substantially better agreement was achieved than in related measurements of the proton&ndash;helium-3 (<italic>p</italic>-<super>3</super>He) analyzing power, suggesting a sizeable dependence on isospin in the four-nucleon systems.</p> / Dissertation

This dissertation explores the reflexive and performative practices found in Mocha Jean Herrup's documentary work, POM, LESBIANFILM, and A FEW GOOD DYKES. By exploiting realism's failure to ever fully represent, reflexive and performative techniques enable a queer discourse. These techniques create 1) a parodic premise that calls attention to the disjunction between documentary's legitimizing conventions and queer as a viable subject, 2) a subjectification of the insider-outsider that troubles distinctions between the audience and the subject and the filmmaker and the subject, and 3) enables the embodied knowledge of queer subjectivity to emerge. / text