Orientador: Gastão Inácio Krein / Banca: Eduardo de Souza Fraga / Banca: Roberto André Kraenkel / Resumo: Estudamos a evolução temporal de parâmetros de ordem conservados e não conservados empregando o formalismo das equações cinéticas semi-fenomenológicas de Ginzburg-Landau-Langevin da teoria clássica das transições de fase dinâmicas. Apresentamos uma aplicação do formalismo ao problema do desconfinamento de quarks e glúons na QCD, em que o parâmetro de ordem conservado é a densidade bariônica e o parâmetro de ordem não conservado é o loop de Polyakov. As equações cinéticas são resolvidas numericamente empregando um esquema semi-implícito no tempo e um método de diferenças finitas com transformada de Fourier rápida para as coordenadas espaciais. Resultados de simulações numéricas são apresentados para valores médios dos parâmetros de ordem e para as funções de estrutura / Abstract: We study the time evolution of conserved and nonconserved order parameters employing the formalism of the semiphenomenological Ginzburg-Landau-Langevin kinetic equations of the classical theory of dynamical phase transitions. We present an application of the formalism to the deconfinement problem of quarks and gluons in QCD, where the conserved order parameter is the baryon density and the non-conserved order parameter is the Polyakov loop. The kinetic equations are solved numerically employing a semi-implicit scheme for the time variable and a finite-difference method with fast Fourier transform for the space coordinates. Results of the numerical simulations are presented for the average values and structure functions of the order parameters / Mestre

Non-stationary motion of a cracked rotating shaft with accelerating or decelerating angular velocity Ω through a critical speed is studied. The shaft has a breathing transverse crack and a disk. There are two parts, which are the investigation of flexural response, neglecting the torsional vibrations, and the investigation of flexural-torsional response. In both studies the longitudinal vibration and the influence of shear deformation are neglected. The boundary conditions of the supports are simply supported for the transverse displacements and fixed-free in relation to torsion (for the flexural-torsional response only). The transverse surface crack, which causes a geometric discontinuity, is replaced by generalized moments at the crack location. The equations of motion follow the formulation of Wauer. Galerkin’s method and numerical integration are used to obtain approximate solutions. The maximum responses are determined. The effects of the acceleration and deceleration rate and the different parameters of the breathing cracked rotating shaft, such as crack depth, crack location, disk location, disk eccentricity, disk eccentricity angle, and disk mass, are studied. The influence of internal damping, external damping, and torsional external damping are investigated. Comparisons with an open cracked rotating shaft and an uncracked rotating shaft are also presented. The influence of torsional deformation is analyzed. The results are presented in tables and figures. / Master of Science

Thesis (Ph.D.)--M.I.T, Dept. of Physics, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / by Cyrus Reza Safinya. / Ph.D.

Thesis (Ph. D.)--McMaster University (Canada), 1990. / Source: Dissertation Abstracts International, Volume: 52-10, Section: B, page: 5290. Supervisor: M.F. Collins.

Thesis (Ph.D.)--McMaster University, 2004. / Advisor: David Venus. Includes bibliographical references (leaves 138-144). Also available via World Wide Web.

Orientador: Mário Noboru Tamashiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-10-31T13:34:08Z (GMT). No. of bitstreams: 1 Oliveira_FranciscoOlivade_M.pdf: 8605584 bytes, checksum: 238f8b9df41bbaab50c51d355549ac7d (MD5) Previous issue date: 2016 / Resumo: Neste trabalho é realizada uma sintética revisão bibliográfica acerca do estudo de filmes monomoleculares na interface ar-água (filmes de Langmuir), seu desenvolvimento histórico e relação atual com tópicos avançados em física de membranas biológicas e biomiméticas, além das vantagens e desvantagens de algumas técnicas experimentais para caracterização de filmes de Langmuir. Visando a descrição de filmes de Langmuir formados por fosfolipídios, são discutidos alguns modelos teóricos como preâmbulo para a apresentação do modelo de gás de rede de Doniach (Doniach lattice gas: DLG), para o qual é apresentada a solução em aproximação de pares, implementada através de cálculos exatos na rede de Bethe. Por fim, os parâmetros do modelo em aproximação de pares são ajustados a dados experimentais obtidos de isotermas de compressão-expansão para dois fosfolipídios zwitteriônicos: o dimiristoilfosfatidilcolina (DMPC) e o dipalmitoilfosfatidilcolina (DPPC) / Abstract: In this work, we present a brief bibliographic review on the study of monomolecular films on the air-water interface (Langmuir films), their historical development and present relation with advanced subjects on biological and biomimetic membranes, besides the advantages and disadvantages of certain experimental techniques for the characterization of Langmuir films. In order to describe phospholipid Langmuir films, we discuss some theoretical models as a preamble to presenting the Doniach lattice gas (DLG) model, which we solve in the pair approximation, implemented through exact calculations on the Bethe lattice. Finally, we adjust the parameters of the model in the pair approximation to experimental data obtained from compression-expansion isotherms for two zwitterionic phospholipids: dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC) / Mestrado / Física / Mestre em Física / 1186359/2013 / CAPES