Submitted by (ana.araujo@ufrpe.br) on 2016-08-01T17:35:24Z No. of bitstreams: 1 Kleber Napoleao Nunes de Oliveira Barros.pdf: 2964667 bytes, checksum: a3c757cb7ed16fc9c38b7834b6e0fa29 (MD5) / Made available in DSpace on 2016-08-01T17:35:24Z (GMT). No. of bitstreams: 1 Kleber Napoleao Nunes de Oliveira Barros.pdf: 2964667 bytes, checksum: a3c757cb7ed16fc9c38b7834b6e0fa29 (MD5) Previous issue date: 2010-02-22 / It is presented in this work the growth model nonlinear Chapman-Richards with distribution of errors following the new class of symmetric models processed and Bayesian inference for the parameters. The objective was to apply this structure, via Metropolis-Hastings algorithm, in order to select the equation that best predicted heights of clones of Eucalyptus urophilla experiment established at the Agronomic Institute of Pernambuco (IPA) in the city of Araripina . The Gypsum Pole of Araripe is an industrial zone, located on the upper interior of Pernambuco, which consumes large amount of wood from native vegetation (caatinga) for calcination of gypsum. In this scenario, there is great need for a solution, economically and environmentally feasible that allows minimizing the pressure on native vegetation. The generus Eucalyptus presents itself as an alternative for rapid development and versatility. The height has proven to be an important factor in prognosis of productivity and selection of clones best adapted. One of the main growth curves, is the Chapman-Richards model with normal distribution for errors. However, some alternatives have been proposed in order to reduce the influence of atypical observations generated by this model. The data were taken from a plantation, with 72 months. Were performed inferences and diagnostics for processed and unprocessed model with many distributions symmetric. After selecting the best equation, was shown some convergence of graphics and other parameters that show the fit to the data model transformed symmetric Student’s t with 5 degrees of freedom in the parameters using Bayesian inference. / É abordado neste trabalho o modelo de crescimento não linear de Chapman-Richards com distribuição dos erros seguindo a nova classe de modelos simétricos transformados e inferência Bayesiana para os parâmetros. O objetivo foi aplicar essa estrutura, via algoritmo de Metropolis-Hastings, afim de selecionar a equação que melhor estimasse as alturas de clones de Eucalyptus urophilla provenientes de experimento implantado no Instituto Agronômico de Pernambuco (IPA), na cidade de Araripina. O Polo Gesseiro do Araripe é uma zona industrial, situada no alto sertão pernambucano, que consume grande quantidade de lenha proveniente da vegetação nativa (caatinga) para calcinação da gipsita. Nesse cenário, há grande necessidade de uma solução, econômica e ambientalmente, viável que possibilite uma minimização da pressão sobre a flora nativa. O gênero Eucalyptus se apresenta como alternativa, pelo seu rápido desenvolvimento e versatilidade. A altura tem se revelado fator importante na prognose de produtividade e seleção de clones melhores adaptados. Uma das principais curvas de crescimento, é o modelo de Chapman- Richards com distribuição normal para os erros. No entanto, algumas alternativas tem sido propostas afim de reduzir a influência de observações atípicas geradas por este modelo. Os dados foram retirados de uma plantação, com 72 meses. Foram realizadas as inferências e diagnósticos para modelo transformado e não transformado com diversas distribuições simétricas. Após a seleção da melhor equação, foram mostrados alguns gráficos da convergência dos parâmetros e outros que comprovam o ajuste aos dados do modelo simétrico transformado t de Student com 5 graus de liberdade utilizando inferência Bayesiana nos parâmetros.

Submitted by (ana.araujo@ufrpe.br) on 2016-08-03T15:09:46Z No. of bitstreams: 1 Luiz Medeiros de Araujo Lima Filho.pdf: 529199 bytes, checksum: 06cae9ad9a02975b786cf55a000dbc5b (MD5) / Made available in DSpace on 2016-08-03T15:09:46Z (GMT). No. of bitstreams: 1 Luiz Medeiros de Araujo Lima Filho.pdf: 529199 bytes, checksum: 06cae9ad9a02975b786cf55a000dbc5b (MD5) Previous issue date: 2009-02-13 / Historically, the wood of the eucalyptus is used for the most varied applications, such as; firewood, charcoal, cellulose, railway sleepers, posts for electrification, bark to tan leather, essential oils, civil construction, etc. The Gypsum Pole of Araripe in Pernambuco is a great firewood consumer for the gypsum production. Due to great need to find economical and environmental alternatives for the area, the sustainable production of eucalyptus that is a fast growth tree with great versatility has an important role. In the planning of the sustainable forest management there is a variable of extreme importance: the growth. To model the growth is fundamental in the prognosis of the productivity, site quality and dynamics of populations. Usually, the growth curves are fitted through nonlinear models developed empirically to relate, for instance, height and age. The Chapman-Richards model is a nonlinear model frequently used to model forest growth. In studies of this type, in general, it is assumed that the errors follow approximately the normal distribution. However, to model the growth assuming that the errors have a normal distribution is quite sensitive to atypical values that can happen, and generate bad estimates of the parameters. To correct that problem a new class of transformed symmetrical models was developed considering for the errors symmetrical continuous distributions with heavier tails than the normal distribution and allowing a possible nonlinear structure for the mean. With the expectation of obtaining better estimates of eucalyptus growth, it was applied to the Chapman-Richards model the following distributions of the errors: normal, t of Student, Cauchy, exponential potency, logistics I and logistics II. The t distribution of Student with 2 degrees of freedom was the most efficient to estimate height and circumference growth of eucalyptus in the Gypsum Pole of Pernambuco. / Historicamente, a madeira do Eucalyptus é usada para os mais variados fins, tais como; lenha, carvão vegetal, celulose, dormentes ferroviários, postes para eletrificação, casca para curtir couro, óleos essenciais, construção civil, etc. O Pólo Gesseiro do Araripe em Pernambuco é um grande consumidor de madeira para produção de gesso. Devido à grande necessidade de se buscar uma alternativa econômica e ambiental para a região é de interesse obter uma produção sustentável para o Eucalyptus, uma vez que esta é uma árvore de rápido crescimento e grande versatilidade. No planejamento do manejo florestal sustentado uma variável é de extrema importância: o crescimento. Sua modelagem é fundamental na prognose da produtividade, qualidade do local e dinâmica de populações. Geralmente, as curvas de crescimento são estudadas por meio de modelos não-lineares desenvolvidos empiricamente para relacionar, por exemplo, altura e idade. Um modelo não-linear bastante utilizado na prática para modelar curvas de crescimento é o modelo de Chapman-Richards. Em estudos deste tipo, em geral, assume-se que os erros seguem distribuição normal. Contudo, a modelagem sob a suposição de erros com distribuição normal é bastante sensível a valores atípicos que por ventura possam ocorrer, podendo distorcer as estimativas dos parâmetros. Para corrigir esse problema Cordeiro et al. (2009) desenvolveram uma nova classe de modelos simétricos transformados considerando para os erros distribuições contínuas simétricas com caudas mais pesadas do que a distribuição normal e permitindo uma possível estrutura não-linear para a média. Dessa forma, com a expectativa de obter melhores estimativas de crescimento de Eucalyptus, aplicaram-se ao modelo de Chapman-Richards as seguintes distribuições dos erros: normal, t de Student, Cauchy, exponencial potência, logística I e logística II que apresentou a distribuição t de Student com 2 graus de liberdade com melhores estimativas de crescimento em altura e circunferência de Eucalyptus no Pólo Gesseiro de Pernambuco.

and Prague's role within it. It also looks at the cultural relationship between Chapman's journey to Czechoslovakia. The second chapter focuses on the clash bet Chapman and the Czechoslovak intermediaries of US culture such as Josef Škvorecký, Lubomír Dorůžka, and Jan Zábrana and the competing versions of African American poetry, especially in Abraham Chapman's anthology of Black diaspora poetry Černošská : světová antologie

La miniaturisation de plus en plus poussée (micro et nano) des systèmes mécanique connaît un important développement depuis une dizaine d'années. Leur conception et réalisation nécessite une connaissance approfondie des écoulements micro-fluidiques. Dans le domaine énergétique, le rendement d'un moteur thermique se dégrade sérieusement lors d'une réduction d'échelle. En effet, les pertes de chaleur pariétales peuvent devenir aussi importantes que l'énergie libérée. Une voie prometteuse consiste à utiliser les ondes de choc / détonation pour accélérer la libération d'énergie. Dans ce cas, la détonation peut être assimilée à une onde de choc inerte, couplée à une zone de réaction, caractérisée par la présence d'instabilités longitudinales et transverses, soumettant ainsi le front de choc à de violentes accélérations / décélérations. L'objectif de la thèse est de mieux appréhender la structure moyenne de la zone de réaction qui s'étend du choc jusqu'à la surface sonique. Sur le plan de la modélisation numérique, les équations de Navier-Stokes compressibles, multi-espèces, réactives sont résolues au sein du solveur CHOC-WAVES développé au CORIA, avec une thermodynamique variables et des coefficients de transport dépendant des espèces. La condition de Chapman-Jouguet généralisée a été élaborée et confirmée par les résultats de simulations numériques dans le cas d'une détonation multidimensionnelle stable. En particulier, il a été montré que les instabilités transverses s'atténuaient avec la réduction d'échelle. A cet effet, un scénario a été proposé pour expliquer le déficit de la vitesse du front de détonation, en se basant sur la structure de la poche subsonique aval, en corrélation avec l'épanouissement de la couche limite. Ce schéma partage de fortes similitudes avec la macro-détonation, tout en gardant des différences. En particulier, il a été montré que la forte vorticité, produite au niveau de la singularité de Prandtl-Meyer, souvent négligée dans les modèles de macro-détonation, diffusait au sein de la poche subsonique. Ces résultats tout à fait originaux ont permis une avancée significative dans la compréhension du mécanisme de propagation des fronts de détonation stables et confinées. / Progress towards the miniaturization of increasingly advanced micro- and nano-electromechanical systems has highlighted the need for a better knowledge of the design of such devices. knowledge of micro-nano pipe flows is still mandatory. In field of energy power generation, as the systems are scaled down, the thermal efficiency of conventional propellant devices is seriously degraded due to significant heat losses which can cause the combustion extinction. A promising approach is to use shock or detonation waves in gazeous media to enhance chemical reaction rates. A detonation is a rapid regime of burning in which a strong shock ignites the fuel and the burning proceeds to equlibrium behind the shock, while the energy released continues to drive the shock. It is also characterized by the presence of longitudinal and transverse instabilities, thereby subjecting the shock front to violent deceleration / acceleration. The objective of this thesis is to better understand the mean structure of the reaction zone that extends from the shock to the sonic surface. As for numerical modelling, the compressible multi-species reactive Navier-Stokes equations are solved using an in-house code "CHOC-WAVES", including variable thermodynamic and transport coefficients depending on the species. The Generalized Chapman-Jouguet condition was developed and corroborated by the numerical results in the case of stable multidimensionnal detonation. More specially, it was shown that the transverse instabilities are attenuated with the scale reduction.To this end, a scenarion, based on the structure of downstream subsonic pocket, which is correlated to the development of the boundary layer, has been proposed to explain the deificit of the detonation from velocity. This scheme shares many similarities with the macro-detonation, while keeping some differences. In particular, it was shown that the strong vorticity, generated at the Prandlt-Meyersingularity and often neglected in macro-detonation models, diffuses in the subsonic pocket. The present contribution enables us to shade more physical insight for the propagation of stable and confined detonation fronts.

This thesis focuses on several paintings of the Mexican landscape produced by Conrad Wise Chapman (1842 – 1910) and held by the Valentine Richmond History Center in Richmond, Virginia. Chapman lived in Mexico from 1865 to 1867 and from 1883 to 1908 (with a few short absences), and during this period, produced a large number of landscapes, which are the subject of this thesis and will be considered as an amalgamation of both nineteenth-century Mexican landscape painting and traveler-art. It is the purpose of this study to demonstrate that Chapman’s artistic style embodies both classical components of landscape painting and characteristics commonly associated with traveler-art. This investigation of Chapman’s Mexican oeuvre provides significant insight into a period of the artist’s career that has long been neglected, and it examines several works of art not yet considered by scholars.

This thesis presents detailed description of the development of two computer codes written in FORTRAN language for the analysis of detonation of energetic mixtures. The first code, named GasPX, can compute the detonation parameters of premixed gaseous mixtures and the second one, named BARUT-X, can compute the detonation parameters of C-H-N-O based solid explosives. Both computer codes perform the computations on the basis of Chapman-Jouguet Steady State Detonation Theory and in chemical equilibrium condition. The computed detonation point by the computer codes is one of the possible solutions of the Rankine&ndash / Hugoniot curve and it also satisfies the Rayleigh line. By examining the compressibility of the gaseous products formed after detonation of premixed gaseous mixtures, it is inferred that the ideal-gas equation of state can be used to describe the detonation products. GasPX then calculates the detonation parameters complying with ideal-gas equation of state. However, the assumption of the ideal gas behavior is not valid for gaseous detonation products of solid explosives. Considering the historical improvement of the numerical studies in the literature, the BKW (Becker-Kistiakowsky-Wilson) Equation of State for gaseous products and the Cowan &amp / Fickett Equation of State for solid carbon (graphite) in the products are applied to the numerical model of BARUT-X. Several calculations of detonation parameters are performed by both GasPX and BARUT-X. The results are compared with those computed by the other computer codes as well as the experimental data in the literature. Comparisons show that the results are in satisfactory agreement with experiments and also in good agreement with the calculations performed by the other codes.

Akademisk avhandling--Tekniska fakulteten--Lund, 1988. / Traduction anglaise.

This thesis aimed at developing multi-scale models and computational methods for aerother-modynamics applications. The research on multi-scale models has focused on internal energy excitation and dissociation of molecular gases in atmospheric entry flows. The scope was two-fold: to gain insight into the dynamics of internal energy excitation and dissociation in the hydrodynamic regime and to develop reduced models for Computational Fluid Dynamics applications. The reduced models have been constructed by coarsening the resolution of a detailed rovibrational collisional model developed based on ab-initio data for the N2 (1Σ+g)-N (4Su) system provided by the Computational Quantum Chemistry Group at NASA Ames Research Center. Different mechanism reduction techniques have been proposed. Their appli-cation led to the formulation of conventional macroscopic multi-temperature models and vi-brational collisional models, and innovative energy bin models. The accuracy of the reduced models has been assessed by means of a systematic comparison with the predictions of the detailed rovibrational collisional model. Applications considered are inviscid flows behind normal shock waves, within converging-diverging nozzles and around axisymmetric bodies, and viscous flows along the stagnation-line of blunt bodies. The detailed rovibrational colli-sional model and the reduced models have been coupled to two flow solvers developed from scratch in FORTRAN 90 programming language (SHOCKING_F90 and SOLV-ER_FVMCC_F90). The results obtained have shown that the innovative energy bin models are able to reproduce the flow dynamics predicted by the detailed rovibrational collisional model with a noticeable benefit in terms of computing time. The energy bin models are also more accurate than the conventional multi-temperature and vibrational collisional models. The research on computational methods has focused on rarefied flows. The scope was to formu-late a deterministic numerical method for solving the Boltzmann equation in the case of multi-component gases with internal energy by accounting for both elastic and inelastic collisions. The numerical method, based on the weighted convolution structure of the Fourier trans-formed Boltzmann equation, is an extension of an existing spectral-Lagrangian method, valid for a mono-component gas without internal energy. During the development of the method, particular attention has been devoted to ensure the conservation of mass, momentum and en-ergy while evaluating the collision operators. Conservation is enforced through the solution of constrained optimization problems, formulated in a consistent manner with the collisional in-variants. The extended spectral-Lagrangian method has been implemented in a parallel com-putational tool (best; Boltzmann Equation Spectral Solver) written in C programming lan-guage. Applications considered are the time-evolution of an isochoric gaseous system initially set in a non-equilibrium state and the steady flow across a normal shock wave. The accuracy of the proposed numerical method has been assessed by comparing the moments extracted from the velocity distribution function with Direct Simulation Monte Carlo (DSMC) method predictions. In all the cases, an excellent agreement has been found. The computational results obtained for both space homogeneous and space inhomogeneous problems have also shown that the enforcement of conservation is mandatory for obtaining accurate numerical solutions.

Thesis (Ph. D.)--Bob Jones University, 1988. / Bibliography: leaves 365-369.

Akademisk avhandling--Tekniska fakulteten--Lund, 1988. / Résumé en anglais.