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This theoretical study has been undertaken in order to provide insights into the steady two-dimensional laminar film condensation heat transfer on an isothermal vertical flat wall and a cylindrical surface. Condensation is given to both the pure water vapor and water vapor-air mixture. Only the saturated state of the bulk vapor is considered. The effects of liquid-vapor resistance, gas-solubility in the condensate, thermal diffusion and diffusion thermo are neglected. The presence of air as non-condensing gas has been fully accounted for in this study. The physical properties of the condensate liquid are taken to be those of saturated water at the appropriate temperature. The properties of the vapor region are considered to be constant except for the density of the mixture. The method of solution is based on the numerical techniques of laminar boundary layer theory. By using liquid-vapor interface matching, an approximate integral solution is obtained. In this study, it was found that the presence of a small amount of air as a non-condensing gas in the water vapor-air mixture plays a decisive role in decreasing the condensation heat transfer. The decrease is more pronounced at lower bulk temperature, TV, and higher values of (TV-TW). As the mass fraction of air in the bulk, W∞, increases, the heat transfer decreases monotonically.

No description available.

This study uses a random coefficient estimation procedure to analyze the U.S. gasoline market from 1960-1995 with three main objectives: (1) provide an empirical methodology that can estimate a gasoline demand function capable of performing well in prediction; (2) evaluate the elasticities of the models presented to determine which model is more accurate at capturing supply shocks that impacted gasoline demand; and (3) evaluate the behavior of the elasticites of the beta coefficients. This research will show that the variation from historical economic patterns was a result of supply shocks. I argue that when the OLS model of the gasoline market developed by William H. Greene is used supply shocks are not well captured because the coefficients are fixed. If the random coefficient model developed by P.A.V.B. Swamy is introduced, the coefficients vary over time, and thereby, enable supply shocks to be included in the model and more accurate forecasts are produced, as well as, meaningful time patterns in the beta coefficients. / Master of Arts

Le but de l'étude est de comprendre et de prédire les performances de détection en phase gazeuse des capteurs chimiques à surface de matériaux sensibles. Les travaux ont porté sur des microbalances à quartz revêtues de polysiloxanes fonctionnalisés. Des mesures à l'équilibre, en exposant ces capteurs à différentes vapeurs organiques, ont mis en évidence la sélectivité des matériaux employés. Pour rationaliser ces résultats, les étapes impliquées dans la détection ont été examinées. Des mesures par PM-IRRAS ont permis de montrer la proportionnalité de la réponse vis-à-vis de la quantité d'analyte absorbé. Des affinités en phase condensée ont été déterminées par une nouvelle méthode par RMN d’études de mélanges sans solvant. L'application de cette méthode à des composés modèles a validé le calcul de l'enthalpie de mélange par l'approche de Hansen. Celle-ci permet également d’obtenir calculer les coefficients de Hansen des matériaux sensibles avec des méthodes de contributions de groupes. Enfin, sur ces résultats, un modèle numérique a été construit pour calculer a priori la réponse d'un capteur à partir de la formule chimique des composés sensible et de l'espèce détectée. / The aim of this study is to understand and model the responses of coated chemical sensors for gas phase detection. The work exposed here focuses on quartz crystal microbalance (QCM) coated with functionalized polysiloxanes. Measurements were carried with the QCM exposed to organic vapours when equilibrium was reached. It has been shown that selectivity depends on the material used. To understand that selectivity, each step involved in the detection has been investigated. First of all, with PM-IRRAS, we verified that the frequency shift was proportional to the amount of absorbed analyte. Then, affinity in liquid phase has been determined through a new methodology by NMR. It has also been used, on model system to prove the applicability of Hansen solubility coefficient to calculate mixing free enthalpy. For polymers, those coefficients have been determined using NMR combined with group contribution methods. Based on these descriptors, a numerical model has been built to calculate a priori the performance of a sensor based on, the chemical structure of the sensitive material and of the detected compound.

On étudie dans cette thèse les coefficients de structure et particulièrement leurs dépendancesen n dans le cadre d’une suite des algèbres de doubles-classes. Le premier chapitre est dédié à l’étude des coefficients de structure dans le cas général des centres d’algèbres de groupes finis et des algèbres de doubles-classes. On rappelle dans ce chapitre la théorie des représentationsdes groupes finiset son lien avec les coefficients de structure. On montre que l’étude des coefficients de structure des algèbres de doubles-classes est reliéeà la théorie des paires de Gelfand et auxfonctions sphériques zonales en donnant un théorème similaireà celui de Frobenius. Ce théorème exprime les coefficients de structure d’une algèbre de doubles-classes associée à une paire de Gelfand en fonction des fonctions sphériques zonales. Dans le deuxième chapitre, on rappellele théorème de Farahat et Higmann autour de la propriété de polynomialité des coefficients de structure du centre de l’algèbre du groupe symétriqueainsi que la preuve d’Ivanov et Kerov. On donne une preuvecombinatoire pour lapropriété de polynomialité des coefficients de structure de l’algèbre de Hecke de la paire (S2n, Bn) dans le troisième chapitre. On utilise dans notre preuve une algèbre universelle qui se projette sur l’algèbre de Hecke de la paire (S2n, Bn) pour tout n. On montre aussi que cette algèbre universelle est isomorphe à l’algèbre fonctions symétriques décalées d’ordre 2. Dans le dernier chapitre on présente un cadre général pour la forme des coefficients de structure dans le cas d’une suite des algèbres de doubles-classes.Ce cadre regroupe les propriétés de polynomialité des coefficients de structure du centre de l’algèbre du groupe symétrique et de l’algèbre de Hecke de la paire (S2n, Bn).De plus, on donne des propriétés de polynomialité pour les coefficients de structure du centre de l’algèbre du groupe hypéroctaédral et de l’algèbre de doubles-classes de diag (Sn-1) dans Sn x Sopp n-1. / In this thesis we studied the structure coefficients and especially their dependence on n in the case of a sequence of double-class algebras. The first chapter is dedicated to the study of the structure coefficients in the general cases of centers of group algebras and double-class algebras. We recall in it the representation theory of finite groups and its link with structure coefficients. We show also that the study of the structure coefficients of double-class algebras is related to the theory of Gelfand pairs and zonal spherical functions by giving, in the case of Gelfand pairs, a theorem similar to that of Frobenius which writes the structure coefficients of the double-class algebra associated to a Gelfand pair in terms of zonal spherical functions. In the second chapter, we recall the Farahat and Higman's theorem about the polynomiality of the structure coefficients of the center of the symmetric group algebra as well as the Ivanov and Kerov's approach to prove this theorem. We give a combinatorial proof to the polynomiality property of the structure coefficients of the Hecke algebra of thepair (S2n, Bn) in the third chapter. Our proof uses a universal algebra which projects on the Hecke algebra of (S2n, Bn) for each n. We show that this universal algebra is isomorphic to the algebra of 2-shifted symmetric functions. In the fourth and last chapter we build a general framework which gives us the form of the structure coefficients in the case of a sequence of double-class algebras. This framework implies the polynomiality property of the structure coefficients of both the center of the symmetric group algebra and the Hecke algebra of (S2n, Bn). In addition, we give a polynomiality property for the structure coefficients of both the center of the hyperoctahedral group algebra and the double-class algebra of diag (Sn-1) in Sn x Sopp n-1.

This thesis investigates the design and implementation strategies for a Spanish speech recognition system. It utilizes the speech features of the 242 common Spanish mono-syllables as the major training and recognition methodology. A training database of twelve utterances per mono-syllable is established by applying Spanish pronunciation rules. These twelve utterances are collected through reading six rounds of the same mono-syllable with two different tones. The first pronounced pattern has high pitch of tone one, while the second one has falling pitch of tone four. Mel-frequency cepstral coefficients, linear predictive cepstral coefficients, and hidden Markov model are used as the two feature models and the recognition model respectively. Under the AMD Sempron Processor 2800+ with 1.6GHz clock rate personal computer and Ubuntu 9.04 operating system environment, a correct phrase recognition rate of 86% can be reached for a 4217 Spanish phrase database. The average computation time for each phrase is about 1.5 seconds.

This thesis investigates the design and implementation strategies for a French speech recognition system. It utilizes the speech features of the 425 common French mono-syllables as the major training and recognition methodology. A training database is established by reading each mono-syllable 12 times in 6 rounds. Every mono-syllable is consecutively read twice with different tones. The first pronounced pattern has high pitch of tone 1,while the second one has falling pitch of tone 4. Mel-frequency cepstrum coefficients, linear predictive cepstrum coefficients, and hidden Markov model are used as the two feature models and the recognition model respectively. Under the AMD Athlon xp 2800+ with clock rate 2.2GHz personal computer and Ubuntu 9.04 operating system environment, a correct phrase recognition rate of 86% can be reached for a 3850 French phrase database. The average computation time for each phrase is about 1.5 seconds.

This thesis investigates the design and implementation strategies for a German speech recognition system. It utilizes the speech features of the 434 common German mono-syllables as the major training and recognition methodology. A training database is established by reading each mono-syllable 12 times in 6 rounds. Every mono-syllable is consecutively read twice with different tones. The first pronounced pattern has high pitch of tone 1, while the second one has falling pitch of tone 4. Mel-frequency cepstral coefficients, linear predictive cepstral coefficients, and hidden Markov model are used as the two feature models and the recognition model respectively. Under the AMD Athlon X2-240 with 2.8 GHz clock rate personal computer and Ubuntu 9.04 operating system environment, a correct phrase recognition rate of 84% can be reached for a 3900 German phrase database. The average computation time for each phrase is within 1 second.