Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Jorge Piekarewicz, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (Jan. 19, 2005). Includes bibliographical references.

Stuttgart, Univ., Diss., 2006.

Thesis (Ph.D.)--Memorial University of Newfoundland, 2000. / Restricted until June 2001. Bibliography: leaves 215-226.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (p. 92-102).

University, Diss., 2004--Bonn.

University, Diss., 2005--Kiel.

abstract: The study of subwavelength behavior of light and nanoscale lasing has broad potential applications in various forms of computation i.e. optical and quantum, as well as in energy engineering. Although this field has been under active research, there has been little work done on describing the behaviors of threshold and saturation. Particularly, how the gain-molecule behavior affects the lasing behavior has yet to be investigated. In this work, the interaction of surface-plasmon-polaritons (SPPs) and molecules is observed in lasing. Various phenomenologies are observed related to the appearance of the threshold and saturation regions. The lasing profile, as a visual delimiter of lasing threshold and saturation, is introduced and used to study various parametrical dependencies of lasing, including the number-density of molecules, the molecular thickness and the frequency detuning between the molecular transition frequency and the SPP resonant frequency. The molecular population distributions are studied in terminal and dynamical methods and are found to contain unexpected and theoretically challenging properties. Using an average dynamical analysis, the simulated spontaneous emission cascade can be clearly seen. Finally, theoretical derivations of simple 1D strands of dipoles are presented in both the exact and mean-field approximation, within the density matrix formalism. Some preliminary findings are presented, detailing the observed behaviors of some simple systems. / Dissertation/Thesis / Masters Thesis Chemical Engineering 2017

Made available in DSpace on 2015-05-14T12:14:21Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2227394 bytes, checksum: 05a68822cdf04f42c1f50d5c368cac63 (MD5) Previous issue date: 2011-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / wide range of pathogens are transmitted by a combination of horizontal and vertical transmission; among these are microsporodians, helminths, bacteria and viruses of plants and animals, including important human pathogens such as HIV, HTLV-1, cytomegalovirus, several hepatitis viruses and herpes simplex [Proc. R. Soc. Lond. B 260: 321-327]. In this work, the vertical parasite spreading from parent to offspring and horizontal transmission through infection in a population of moving individuals are discussed using a probabilistic cellular automata implemented on a square lattice. In our model, we generalize the automata proposed in [J. Phys. A : Math. Gen. 27: 1585-1597] to include the vertical transmission. The local rule consists of two subrules: the first one, applied synchronously, models infection, birth and death processes; the second, applied sequentially, describes the motion of individuals. In this model, endemic states may occur (susceptible and infected individuals coexisting) or a disease-free state (without infected). It is worth mentionins that a state in which the entire population becomes infective is possible in the case of perfect vertical transmission, i.e. infected parents give birth only to infected offspring. Moreover, the stability of these states may be analised using a mean-field approximation or grafically verified from the numerical simulations. / Uma ampla faixa de patógenos são propagados por uma combinação de transmissão horizontal e vertical, dentre os quais podemos destacar: microesporídeos, helmintos, bactérias, fungos e vírus de plantas e animais, incluindo importantes microorganismos parasitas de humanos como o HIV, HTLV-1, cytomegalovírus, vários tipos de hepatite e herpes simples [Proc. R. Soc. Lond. B 260: 321-327 (1995)]. Neste trabalho, a transmissão vertical (infecção do genitor para os filhos) e a transmissão horizontal (infecção por contágio) numa população de indivíduos em movimento são discutidos usando um autômato celular probabilístico implementado numa rede quadrada. Em tal modelo, generalizamos o autômato proposto em [J. Phys. A : Math. Gen. 27: 1585-1597 (1994)] para incluir a transmissão vertical. A regra local consiste de duas subregras: a primeira modela de maneira sincronizada os nascimentos, as mortes e as infecções; já a segunda, aplicada sequencialmente, descreve o movimento dos indivíduos. Neste modelo é possível um estado endêmico (suscetíveis coexistindo com infectados) ou um estado livre de doenças (sem infectados). Salienta-se que um estado em que toda a população torna-se infectada é possível no caso de transmissão vertical perfeita, i.e. pais infectados possuem apenas descendentes infectados. Inclusive, a estabilidade destes estados pode ser analizada na aproximação de campo médio para este modelo, ou verificada através dos gráficos dos resultados das simulações numéricas.

L’étude des systèmes avec interactions gravitationnelles à l’aide des outils de la mécanique statistique repose jusqu’à présent sur l’utilisation d’une approximation de type champ moyen, qui néglige par construction les effets à courte portée de l’interaction. Pour commencer, je décris cette approximation dans son contexte historique, à savoir le modèle de la sphère isotherme. Puis, dans le cadre de la mécanique statistique du problème à N -corps, j’introduis un système de sphères dures massives, qui permet de s’affranchir de l’effondrement du système de points matériels. La validité de l’approche hydrostatique est discutée dans l’ensemble microcanonique, en introduisant une limite d’échelle adéquate.Cette étude permet de mettre en avant les critères de validité pour l’approche hydrostatique, et de constater qu’ils peuvent être mis en défaut dans les systèmes astrophysiques de type amas globulaire. Pour mieux les comprendre et les illustrer, je me concentre ensuite sur l’étude d’un modèle de bâtonnets durs massifs à une dimension, dont l’avantage est de permettre tous les calculs analytiques des différentes grandeurs statistiques. Ainsi, je mets en évidence comment l’approche de type champ moyen est mise en défaut pour certains états effondrés.Enfin, dans le but de tenter de décrire des amas globulaires, je développe un modèle comprenant des étoiles célibataires et des étoiles binaires. Ce modèle reproduit bien les effets qualitatifs attendus, et il constitue une première correction satisfaisante au modèle historique de la sphère isotherme. Je met aussi en évidence l’absence d’équilibre thermodynamique au sens strict pour les systèmes considérés. En conclusion, je réalise une discussion succincte de certains éléments dynamiques du problème. / The study of systems with gravitational interactions with the tools of mechanics statistics was based so far on the use of a mean-field approximation, which neglect by construction effects of the short-range interaction. To begin, I describe this approximation in its historical context, namely the model of isothermal sphere. Then, as part of statistical mechanics of many-body problem, I introduce a system of massive hard spheres, which overcomes the collapse of the point partcile system. The validity of the hydrostatic approach is discussed in the microcanonical ensemble, by introducing an appropriate scaling limit.This study helps to highlight conditions of validity of the the hydrostatic approach and show that those conditions may prove defective in astrophysical systems such globular clusters. To better understand and illustrate this point, I focus on the study of a model of massive hard sticks in one dimension, which has the advantage of allowing all analytical calculations of various statistical quantities. Thus, I highlight how the mean field type approach can be wrong for some collapsed states.Finally, in an attempt to describe globular clusters, I develop a model consisting of single stars and binaries stars systems. This model reproduces the expected qualitative effects, and is a good first correction of the historical model of the isothermal sphere. I also highlight the absence of thermodynamic equilibrium in the strict sense for the systems we study. In conclusion, I realize a brief discussion of some dynamical issues.