Neste trabalho tem por objetivo a construção de conjugações suaves de pontos fixos hiperbólicos com condições de não ressonância. Por tanto, inicialmente são apresentados alguns conceitos básicos sobre espaços de Banach e alguns resultados de equações diferenciais ordinárias em espaços de Banach e sistemas dinâmicos, apresentamos o teorema de Hartman Grobman como motivação inicial de Linearização. Apresentamos também vários exemplos como motivação para estudar o Teorema de Sternberg para contrações hiperbólicas, o principal resultado estudado nesta dissertação para contrações hiperbólicas / This work has the objetive of building smooth conjugations of hyperbolic fixed points with non-resonance conditions. So, first we present some basics of Banach spaces and some results of ordinary differential equations in Banach spaces and dynamical systems, we present the theorem of Hartman Grobman as original motivation for linearization . We also present several examples as motivation to study the Sternberg theorem for hyperbolic contractions, as main result studied in this dissertation

Orientador: Estevão Tomomitsu Kimpara / Coorientador: Marcos Yutaka Shiino / Banca: Guilherme de Siqueira Ferreira Anzaloni Saavedra / Banca: Júlio César Brigolini de Faria / Resumo: O objetivo do estudo foi avaliar o comportamento mecânico de uma cerâmica, à base de dissilicato de lítio, em ensaio de flexão com as extremidades fixas. Este estudo particular tem similaridade com caso real de aplicação de prótese em pacientes, o que melhora a avaliação do material quando comparado a ensaios convecionais como o ensaio de flexão em três pontos, com viga simplesmente apoiada. Para isso os corpos de prova foram submetidos à três tipos de envelhecimento: ciclagem mecânica, ciclagem termomecânica, ambas de acordo com os protocolos utilizados na literatura, e ciclagem intrabucal. A ciclagem intrabucal foi realizada por meio da utilização de um dispositivo intrabucal semelhante a uma placa oclusal, na qual foram instalados os corpos de prova, por meio de um dispositivo metálico próprio. Estas placas foram utilizadas em dez voluntários por oito horas, durante o período noturno. As amostras foram posteriormente submetidas ao ensaio mecânico de flexão de três pontos com as extremidades engastadas, para avaliação da resistência residual. Os resultados de resistência residual foram submetidos à análise estatística descritiva (média e desvio padrão) e inferencial, mediante o teste paramétrico de análise de variância (ANOVA) um fator e o teste de Tukey ( = 0,05). As amostras representativas de cada grupo foram observadas em microscópio eletrônico de varredura para análise fractográfica. O tipo de ciclagem influenciou no comportamento mecânico da cerâmica, apresentando si... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to evaluate the behavior of lithium disilicate ceramic in similar condition to a partial fixed prosthesis of three elements by subjecting to three types of aging (n=10): mechanical cycling, thermomechanical cycling, both according to the protocols used in the literature, and intraoral cycling. The intraoral cycling was accomplished by using an intraoral device, which is similar to an occlusal splint. They were installed with the samples (CP) by means of a metallic device that was fixed in balanced contact condition with the remainder of the occlusal surface of the plate. These plates were used in ten volunteers for eight hours during the evening. After fatigue, the samples were subjected to three-point bending tests with clamped ends to evaluate the residual strength. The residual strength results were submitted to descriptive statistics (mean and standard deviation) and inferential by the parametric analysis of variance (ANOVA), with one factor and Tukey test ( = 0.05). In addition, representative samples of each group were observed in a scanning electron microscope (SEM) for fractographic analysis. The cycling condition influenced the mechanical behavior of ceramic with statistical significance of (p = 0,000), and the intraoral cycling group showed the lowest residual flexural strength. In fractographic analysis, they showed that the origin of fracture was in the tensile zone, but there was a secondary fracture origin represented by a twisted zone. Therefore, all types of ....(Resumo completo, clicar acesso eletrônico abaixo) / Mestre

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O objetivo deste trabalho é verificar como a arte e a moda, representam o cotidiano no contemporâneo, principalmente no que diz respeito à crítica ao sistema vigente, a representação do instante formador do cotidiano e da apropriação da arte pelo consumo. Por necessidade de um recorte metodológico as Artes de Muro também conhecidas como Grafites foram escolhidas como fenômeno de observação por ser uma arte pública e de fácil acesso a maioria dos indivíduos que interagem com o espaço urbano. Observa-se que embora a Arte de Muro seja em sua maioria uma crítica aos moldes impostos pelo sistema, ela acaba por ser aglutinada por ele e transformada em bens de consumo de alto valor. / The objective of this work is to see how art and fashion, represent the everyday in contemporary, especially with regard to the criticism of the current system, the representation of time trainer every day and appropriation of art by consumption. On the need for a methodological approach for the Arts also known as Wall Graffiti were chosen as a phenomenon of observation to be a public and easily accessible to most individuals who interact with the urban space art. It is observed that although the Art Wall is mostly a critique of the molds imposed by the system, it turns out to be bonded by it and transformed into consume high value goods.

Rearrangements are two measurable real-valued functions that have equal measure of pre-images of upper level sets. In this thesis, I will investigate several matters and problems relating to rearrangements: the relationship between assumptions on the measure space and desirable properties of the set of rearrangements, and the validity of rearrangement inequalities; generalising the Mountain Pass Lemma over rearrangements; and applying topological degree theory to boundary value problems involving rearrangements. From suppositions on the measure space, such as the measure space having finite measure and no atoms, it can proved that the set of rearrangements is contractible and locally contractible. The Mountain Pass Lemma over rearrangements can be generalised, so instead of considering continuous paths from the closed unit interval to the set of rearrangements; it will consider the continuous functions from the closed unit disc into the set of rearrangements. Topological degree theory is used to associate admissible triples of functions, sets and points with integers. These methods will be applied to a boundary value problem involving rearrangements, where the domain is almost equal to the union of balls, which has been studied using variational methods, providing new multiplicity results. The minimum number of solutions to this boundary value problem is found to be related exponentially to the number of balls contained in the domain.

Fixed bed reactors are an essential part of the chemical industry as they are used in a wide variety of chemical processes. To better model these systems a more fundamental understanding of the processes taking place in a fixed bed is required. Fixed bed models are traditionally based on high tube-to particle diameter ratio (N) beds, where temperature and flow profile gradients are mild and can be averaged. Low-N beds are used in extremely exo- and endothermic processes on the tube side of tube and shell type reactors. In these beds, heat transfer is one of the most important aspects. The importance of accurate modeling of heat transfer and its dependence on accurate modeling of the flow features leads to the need for studying the phenomena in these low-N beds in detail. In this work a comparative study is made of the influence of spherical and cylindrical packing particle shapes, positions and orientations on the rates of heat transfer in the near-wall region in a steam reforming application. Computational Fluid Dynamics (CFD) is used as a tool for obtaining the detailed flow and temperature information in a low-N fixed bed. CFD simulation geometries of discrete particle packed beds are designed and methods for data extraction and analysis are developed. After conceptual and quantitative analysis of the simulation data it is found that few clear relations between the complex phenomena of flow and heat transfer can be easily identified. Investigated features are the orientations of the particle in the flow, and many design parameters, such as the number and size of longitudinal holes in the particle and external features on the particle. We find that many of the investigated features are related and their individual influences could not be isolated in this study. Some of the related features are, for example, the number of holes in the particle design and the particle orientation in the flow. Some general conclusions could be drawn. External features on the particles enhance the overall heat transfer properties by better mixing of the flow field. When holes are present in the cylindrical particle design, heat transfer effectiveness can be improved with fewer larger holes. After identifying the packing-related features influencing the near-wall heat transfer under steam reforming conditions, an attempt was made to incorporate the steam reforming reaction in the simulation. In the initial attempts the reaction was modeled as an energy flux at the catalyst particle surfaces. This approach was based on the abilities of the CFD code, but turned out not accurate enough. Elimination of the effects of local reactant depletion and the lack of solid energy conduction in the catalyst particles resulted in an unphysical temperature field. Several suggestions, based on the results of this study, are made for additional aspects of particle design to be investigated. Additionally, suggestions are made on how to incorporate the modeling of a reaction in fixed bed heat transfer simulations.

Modeling of fluid flow, heat transfer and reaction in fixed beds is an essential part of their design. This is especially critical for highly endothermic reactions in low tube-to-particle diameter ratio (N) tubes, such as methane steam reforming (MSR) and alkane dehydrogenation as two important commercial reactions. The modeling of fixed bed reaction is available in literatures with lots of assumptions. However, there is a need for implementing the reaction conditions with diffusion aspects on a real fixed bed reactor without assuming any pseudo conditions. Computational fluid dynamics (CFD) has been found as a suitable tool by many researchers to simulate fixed beds. CFD can simulate complex geometry of randomly-packed tubes, and provides us with more fundamental understanding of the transport and reaction phenomena in reactor tubes. CFD can be used to obtain detailed three-dimensional velocity, species and temperature fields that are needed to improve engineering approaches. Previously, the geometry of 120-degree wall segment (WS) of the whole reactor tube has been studied in our group. Previous works have introduced the coupling of gas flow and resolved species and temperature gradients inside pellets by CFD for methane steam reforming (MSR) and propane dehydrogenation (PDH) without considering deactivation. The deactivation of catalysts due to carbon formation is an important problem in industry, such as steam reforming and the catalytic dehydrogenation of alkanes, which are both strongly endothermic reactions. Many researches were carried out to study the effect of carbon formation and catalyst deactivation on the reactor performance. The local carbon deposition on catalysts can cause particle breakage and strongly decrease reaction rates. Catalyst deactivation in heated tubes removes the heat sink and can result in local hot spots that weaken the reactor tube. This is particularly a problem for a low tube-to-particle diameter ratio fixed bed reactor. A 3D resolved CFD model simulation was used to study the local details of carbon deposition in which the reactions and deactivation take place inside the catalytic solid particles. CFD simulations of flow, heat transfer, diffusion and reaction were carried out using the commercial CFD code FLUENT/ANSYS 6.3 in a 3D 120-degree periodic wall segment with N=4. The mesh used boundary layer prism cells at both the inside and outside particle surfaces and at the tube wall. These reactions were represented in the solid particles using user-defined scalars to mimic species transport and reaction, with user-defined functions supplying reaction rates. Diffusion in the particles was modeled by Fick's law using an effective diffusivity, given by Hite and Jackson's approximation of the Dusty Gas Model. The transient developments of particle internal gradients and carbon accumulation have been studied for the early stages of deactivation. Carbon concentration is initially strongest close to the surface and in the high temperature regions of the catalysts and affected by the wall heat flux. Deactivation of the endothermic reactions causes a slow increase in the average catalyst temperature. The second stage of the research was the verification of our CFD reaction model with experimental data under reacting conditions. The highly endothermic commercial methane steam reforming (MSR) reaction was studied experimentally in a fixed bed reactor. The temperature contributions inside catalyst particles were measured. The MSR reaction showed strong effects on the temperature profile along the reactor. Then, a CFD model was used to predict temperature profiles under MSR reaction conditions. Comparison of CFD and experimental data showed very good qualitative as well as quantitative agreement for temperature inside catalyst particles at different inlet gas temperatures. The last stage was to develop a fundamental energy equation without introducing new adjustable parameters to study heat transfer in fixed beds. In the past, many researchers have been carried out to simulate the heat transfer in fixed bed reactors by using kr (effective thermal conductivity) and hw (heat transfer coefficient). But the classical model with kr and hw cannot give a correct T(r) near tube wall, where deactivation is strongest. Therefore we need a better model which can represent the near wall heat transfer more accurate. CFD modeling was used to develop pseudo-continuum model for T(r) using Vr(r,z) and Vz(r). To get better temperature at the wall vicinity close to the physical reality. In this model radial thermal conductivity was obtained from Zehner-Schlünder model. The convection heat transfer was calculated in the 2D flow fluid from the CFD run. Results were obtained for Reynolds numbers in the range 240€“1900. The accuracy of the new model has been validated by analytical solution. The temperature calculated by the new velocity field pseudohomogenous energy equation showed reasonable quantitative agreement with values predicted by the CFD model.

"No matter how good a portfolio manager is, she or he can not makes right investment decisions without the right information. It is all about data: how can many megabytes of data must be loaded into a continuously growing system, stored efficiently, and made easily accessible to all queries and to all applications? In this project, we build a decision database for managing a portfolio of fixed-income investments. We review the key features of the database architecture and describe key steps in processing the available date. In addition, we review some common analyses that are done by the portfolio manager by studying the report needed for a study of the investment duration at the sector level. "

As biomass and municipal solid wastes become increasingly viable fossil fuels alternatives, more researches are being conducted to improve on the processes for their conversion to energy or energy carriers. Gasification is one of such processes and it forms the core of this project. This project presents a specified design of a small-scale fixed-bed reactor for the purpose of investigating the gasification processes of biomass and municipal solid wastes. Gas extraction ports are evenly distributed along the height of the reactor to extract product gases and accommodate thermo-couples for temperature measurement. A cyclone separator was incorporated to clean the gases as well as extract bio-oil from the gases. / Program: Masterutbildning i energi- och material

Diploma thesis is dedicated to specifics of belarusian accounting . The aim is to provide a basic understanding of accounting in the Republic of Belarus in terms of legislation and practice. More attention will be given to identification gaps in this accounting system and future changes, which should eliminate these gaps. Another aim of my thesis is to compare the editing of fixed assets according to Czech and Belarusian legislation. The focus will also link to the amortization and tax regulation.