Dissertations / Theses on the topic 'Mechaninė sistema'
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Kiseliauskaitė, Eglė. "Savaime ir priverstinai virpanti procesų transformavimo sistema." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2004. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2004~D_20040604_130419-58999.
Full textPuiša, Romanas. "Adaptyvieji stochastiniai algoritmai mechaninių sistemų elementams optimizuoti." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2005. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2005~D_20051102_105606-30576.
Full textThe thesis addresses the development of stochastic algorithms to mechanical-structure optimisation problems. Since structure optimisation problems encountered in mechanical engineering are usually highly nonlinear, nosy, and discrete, stochastic algorithms represent reasonable optimisation methods for them. This evidence is justified by many successful applications of stochastic algorithms (e.g. evolutionary algorithms) on those mechanical engineering problems, where deterministic methods are hardly applicable. This work embodies four new original approaches concerning about (1) the theoretical measures of the algorithmic efficiency, (2) the further development of existing and (3) the design of new stochastic algorithms. Thus, the first approach aims at predicting the run-time efficiency of evolutionary algorithms through the calculation of higher-order statistical moments, namely the skewness and the kurtosis, and the use of a new proposed statistic–the best fitness frequency. The performed statistical analysis is based on two hypothesises: (1) a population, considered as a distribution of fitness values, varies over run-time by changing its shape, and (2) such a variance of the fitness-distribution shape reflects fitness landscape regions. The optimisation results performed on some theoretical test functions support the stated hypotheses. The presented statistical efficiency analysis can be used only in population-based stochastic algorithms. The following two approaches... [to full text]
Salgueiro, Andréa Nemes. "Aspectos da decoerência em sistemas quânticos." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/43/43131/tde-02122013-144041/.
Full textWe study the quantum decoherence process in different contexts. In particular, we study decoherence effects in the dynamics of a two-level system coupled to another system which has a continuous energy spectrum. We also investigate when the master equation description, in a Born Markov approximation reproduces the exact solution. We extend this investigation to the model which describes the interaction between a harmonic oscillator and a thermal bath of harmonic oscillators in the rotating wave approximation. We also study the two atom correlation scheme originally proposed by Davidovich, Brune, Raimond and Haroche for measuring the decoherence of a mesoscopic superposition of coherent states of a QED cavity in the context of quantum computation. We show that this experiment is equivalent to a quantum computer solving Deutsch\'s problem. We find a way to reduce the errors due to decoherence. Finally, we show how the Zeno effect is related to the decoherence process.
Mokarzel, Sonia Geraij. "Decoerência e Dissipação de Sistemas Quânticos: Técnicas e Aplicações." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/43/43131/tde-02122013-185457/.
Full textIn the present work we developed a perturbative treatment of reduced density matrices which is similar in spirit to Fermi\'s Golden Rule for scattering. We applied the theory to several e- xamples and in particular reproduced the results obtained in the laboratory Kastler Brossel experiment quantifying the relation between decoherence and dissipation characteristic times. On the other hand we developed a simple model for two molecules interacting through a re- servoir. We show that rather surprising results may arise when we have more than two subsys- tems in interaction: in the particular case where both molecules are initially in coherent states, if they are pumped with the same strength, the asymptotic state shows a concentraction of energy on the mode with smallest frequency. This result gives support to a phenomenological model for biological systems where a Bose- Einstein condensation is predicted and the final state also exhibits a concentration of energy in the lowest frequency mode.
Clerice, Guilherme Augusto Marabezzi. "Localização de descargas parciais em transformadores de potência imersos em óleo mineral por meio de cápsulas piezelétricas de baixo custo e sistemas inteligentes /." Bauru, 2014. http://hdl.handle.net/11449/122124.
Full textBanca: Danilo Hernane Spatti
Banca: Fabrício Guimarães Baptista
Resumo: Os transformadores de potência são equipamentos de alto custo e suma importância no sistema elétrico, em virtude de que o seu mau funcionamento impacta diretamente a qualidade da energia elétrica fornecida aos consumidores. Portanto, sistemas de diagnósticos de falhas ocorridas nesses equipamentos podem auxiliar, tanto em manutenções corretivas, quanto preventivas. Este trabalho oferece um método eficiente para localização de descargas parciais em transformadores de potência que utilizam óleo mineral no seu interior, sem a necessidade de métodos intrusivos de diagnóstico. A localização da descarga parcial gerada no interior do transformador é feita por meio de cápsulas piezelétricas de baixo custo, fixadas externamente na caixa do transformador de potência, bem como, através do uso de sistemas inteligentes como redes neurais artificiais sem a utilização do TOA (time of arrival) exigindo triangulação do sinal, que demanda alta complexidade computacional, assim fornecendo as coordenadas de onde se originou a descarga parcial. Neste contexto, a redução do tempo de manutenção ou possível predição da interrupção do serviço desse equipamento faz com que o fornecimento de energia seja feito com melhor qualidade, minimizando os impactos sofridos pelos consumidores pela descontinuidade do serviço prestado pelas concessionárias de energia elétrica
Abstract: The power transformer are equipments with high cost but paramount importance in the electric system as your bad operation can directly impact on the quality of the electric energy provided to the consumers. Therefore, diagnostic systems of occurred failures on this equipment can assist even on corrective maintenance or preventive. This work offers an efficient method to locate partial discharges on the power transformers which use mineral oil inside with no need to use intrusive methods of diagnoses. The location of the partial discharge generated inside of the transformer is made via piezoeletric capsules with low cost. It is fixed externally in the box of the power transformer, as well through the use of intelligent systems as neurotic artificial networks without the use of the TOA (time of arrival) requiring the triangulation signal which demands high computational complexity, thus providing the coordinates where the partial discharge was originated. On this context, the reduction of the time of maintenance or possible prediction of interruption of the service in this equipment results that the energy supply can be made with better quality, minimizing the impacts suffered by the consumers due the discontinuity of the service made by the concessionaires of electric energy
Mestre
Clerice, Guilherme Augusto Marabezzi [UNESP]. "Localização de descargas parciais em transformadores de potência imersos em óleo mineral por meio de cápsulas piezelétricas de baixo custo e sistemas inteligentes." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/122124.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Os transformadores de potência são equipamentos de alto custo e suma importância no sistema elétrico, em virtude de que o seu mau funcionamento impacta diretamente a qualidade da energia elétrica fornecida aos consumidores. Portanto, sistemas de diagnósticos de falhas ocorridas nesses equipamentos podem auxiliar, tanto em manutenções corretivas, quanto preventivas. Este trabalho oferece um método eficiente para localização de descargas parciais em transformadores de potência que utilizam óleo mineral no seu interior, sem a necessidade de métodos intrusivos de diagnóstico. A localização da descarga parcial gerada no interior do transformador é feita por meio de cápsulas piezelétricas de baixo custo, fixadas externamente na caixa do transformador de potência, bem como, através do uso de sistemas inteligentes como redes neurais artificiais sem a utilização do TOA (time of arrival) exigindo triangulação do sinal, que demanda alta complexidade computacional, assim fornecendo as coordenadas de onde se originou a descarga parcial. Neste contexto, a redução do tempo de manutenção ou possível predição da interrupção do serviço desse equipamento faz com que o fornecimento de energia seja feito com melhor qualidade, minimizando os impactos sofridos pelos consumidores pela descontinuidade do serviço prestado pelas concessionárias de energia elétrica
The power transformer are equipments with high cost but paramount importance in the electric system as your bad operation can directly impact on the quality of the electric energy provided to the consumers. Therefore, diagnostic systems of occurred failures on this equipment can assist even on corrective maintenance or preventive. This work offers an efficient method to locate partial discharges on the power transformers which use mineral oil inside with no need to use intrusive methods of diagnoses. The location of the partial discharge generated inside of the transformer is made via piezoeletric capsules with low cost. It is fixed externally in the box of the power transformer, as well through the use of intelligent systems as neurotic artificial networks without the use of the TOA (time of arrival) requiring the triangulation signal which demands high computational complexity, thus providing the coordinates where the partial discharge was originated. On this context, the reduction of the time of maintenance or possible prediction of interruption of the service in this equipment results that the energy supply can be made with better quality, minimizing the impacts suffered by the consumers due the discontinuity of the service made by the concessionaires of electric energy
Acconcia, Thiago Vaz 1991. "Caminhos ótimos degenerados em sistemas termicamente isolados." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276953.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: A termodinâmica é uma teoria do calor e trabalho, a qual descreve perfeitamente os processos quase-estáticos somente. Entretanto, além dos estados de equilíbrio, nós encontramos uma ampla classe de processos operando em tempo finito. Uma meta onipresente na termodinâmica é a otimização dos processes a tempo finito através da minimização do trabalho dissipado ou trabalho em excesso. Para o oscilador harmônico paramétrico, nós derivamos uma família altamente degenerada de protocolos ótimos a tempo finito, ao longo dos quais o trabalho em excesso produzido se anula exatamente. Para isso, o sistema de interesse se mantém termicamente isolado durante todo o processo de atuação do protocolo de switching. Esses protocolos ótimos são obtidos através da teoria de resposta linear para sistemas inicialmente preparados segundo uma distribuição canônica. Para sistemas com um grau de liberdade, mostramos evidências de que esses caminhos ótimos podem também levar à conservação do invariante adiabático correspondente. Além dos resultados analíticos para os osciladores harmônicos clássico e quântico, nós apresentamos resultados numéricos para alguns exemplos anarmônicos. Finalmente, nós reformulamos os resultados anteriores quantificando-os em termos do comprimento termodinâmico para a versão quântica do sistema oscilador harmônico
Abstract: Thermodynamics is a theory of heat and work, which describes perfectly only the quasistatic processes. However, if we shift our view away from the equilibrium states, we find a wide class of processes operating in finite-time. An ubiquitous goal in thermodynamics is to optimize the finite time processes by minimizing the dissipated or excess work. For the parametric harmonic oscillator, we derive a family of degenerated finite-time optimal protocols for which the excess work during a non-equilibrium process vanishes exactly. For this, the system of interest is kept thermally isolated during the switching of a control parameter. These optimal paths are obtained within linear response for systems initially prepared in a canonical distribution. For systems with one degree of freedom, we claim that these optimal paths may also lead to the conservation of the corresponding adiabatic invariant. Besides the analytical results for both classical and quantum harmonic oscillator, we present numerical results for certain anharmonic examples. Finally, we discuss the reformulation of the latter results terms of the thermodynamic length for the quantum version of the harmonic oscillator system
Mestrado
Física
Mestre em Física
Espinoza, Rodrigo Valério. "Sistema estabilizador da adesão de um robô escalador com rodas magnéticas." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/1010.
Full textEste trabalho consiste no desenvolvimento de um sistema estabilizador da adesão de um robô escalador com rodas magnéticas. O projeto deste robô surge da necessidade em automatizar o processo de inspeção de tanques de armazenamento de derivados de petróleo, o qual e atualmente realizado de modo manual. O robô vem sendo desenvolvido no Laboratório de Automação e Sistemas de Controle Avençado (LASCA) da Universidade Tecnológica Federal do Paraná (UTFPR). Primeiramente foi realizada uma análise teórica completa do protótipo, englobando um estudo da estrutura do robô, seus requisitos e as análises de cinemática e dinâmica. Realizou-se então um estudo das rodas magnéticas do robô e das características do campo magnético enquanto ocorre descolamento da roda em superfícies ferromagnéticas. Os dados do campo magnético são adquiridos por meio do magnetômetro presente na unidade de navegação inercial do robô. Implementou-se então uma rede neural artificial do tipo Perceptron Multi-Camadas com o intuito de interpretar os dados do campo magnético e estimar a forca de adesão entre o robô e a superfície. Por fim a quantificação da forca de adesão e utilizada para implementar um sistema de controle de adesão para o robô escalador.
This work consists in the design of an adhesion stabilization system of a climbing robot with magnetic wheels. The robot’s design comes from the need to automatize the inspection process of industrial storage tanks for petroleum products, which is currently performed manually. The robot is being developed in the Laboratory of Automation and Advanced Control Systems (LASCA) of the Federal Technological University of Paraná (UTFPR). First, a complete a theoretical analysis of the prototype was carried out including a study of the robot’s structure, its requirements and the kinematics and dynamics analyses. Then, a study of the robot’s magnetic wheels and the characteristics of the magnetic field in the occurancy of detachment between the magnetic wheel and the ferro-magnetic surfaces was carried out. The magnetic field data is acquired through the magnetometer of the inertial measurement unit sensor of the robot. Then a multilayer perceptron artificial neural network was implemented in order to interpret the magnetic field data and estimate the adhesion force between robot and surface. Finally the adhesion force quantification is used to implement an adhesion control system for the robot.
Pires, Rilder de Sousa. "Difusão singular em um sistema confinado." reponame:Repositório Institucional da UFC, 2013. http://www.repositorio.ufc.br/handle/riufc/13738.
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Patterns of scale invariance, associated with power laws, are often found in nature, for instance, in the fluctuations of prices of items in stock markets and in the energy spectrum of turbulent systems. These two systems and many others that exhibit scale invariance present some common properties: they are comprised of several elements that interact in a non-linear way, are not in equilibrium, and exhibit self-organization. Scale invariance is also found in the correlations observed in the critical state of systems that present phase transitions. The concept of self-organized criticality suggests that the properties of invariance spontaneously arise in complex systems. Several models exhibit properties of self-organized critically, including invasion percolation, sand-piles and the trough model, however it is not clear what are the necessary ingredients for criticality to arise. It is known that this property appears in some non-linear diffusive systems. In this work, we introduce a confining potential in a one-dimensional diffusion model with a singular non-linearity on diffusion coefficient, and analyze how this affects in the steady state of the system. We then derive a diffusion equation and obtain a solution for stationary density profile. Our analytical solution is in good agreement with the numerical results. We also present a statistical study of the distribution of avalanches sizes in this model, and obtain profiles following power laws, what is not usually observed in other one-dimensional systems. We also investigated how these profiles vary when the confinement increases, and using finite size scaling we found a universal curve for the distribution of avalanche sizes. Our results show that the action of confinement in a one-dimensional system can yield scale invariance.
Padrões de invariância de escala, associados à leis de potência, são frequentemente observados na natureza. Alguns exemplos são: flutuações em preços de itens de bolsa de valores e outros investimentos, além do espectro de energia em sistemas turbulentos. Esses dois sistemas e vários outros que exibem invariância de escala têm propriedades em comum: compõem-se de vários elementos que interagem de forma não linear, estão fora do equilíbrio e exibem auto-organização. Invariância de escala também é encontrada nas correlações observadas no ponto crítico de sistemas que apresentam transições de fase. O conceito de criticalidade auto-organizada sugere que as propriedades de invariância emergem espontaneamente em sistema complexos. Vários modelos exibem propriedades criticamente auto-organizadas, entre eles percolação invasiva, pilhas de areia e o modelo de desníveis, no entanto, não se sabe ao certo quais os ingredientes necessários para criticalidade emergir. Sabe-se que essa propriedade se manifesta em alguns sistemas difusivos não lineares. Nesse trabalho, introduzimos um potencial confinante em um modelo de difusão unidimensional com uma não linearidade singular no coeficiente de difusão e analisamos a influência dessa mudança no estado estacionário do sistema. Conseguimos, então, derivar uma equação de difusão do modelo e obtemos uma solução para o perfil de densidade. Nossa solução analítica concorda perfeitamente com os resultados numéricos. Fizemos, ainda, um estudo estatístico do perfil de avalanches do modelo, e obtemos perfis de avalanche em leis de potência, o que normalmente não é observado em outros sistemas unidimensionais. Analisamos, ainda, como esses perfis variam na medida que se aumenta o confinamento, e usando transformações de escala encontramos uma curva universal para os perfis de distribuição de tamanhos de avalanche. Nossos resultados demonstram que a ação do confinamento em um sistema unidimensional pode levar ao surgimento da invariância de escala.
Satulovsky, Javier Eduardo. "Modelo estocástico para um sistema predador-presa." Universidade de São Paulo, 1995. http://www.teses.usp.br/teses/disponiveis/43/43133/tde-28022014-111840/.
Full textIn this work, we introduce and study a stochastic lattice gas model for the evolution of an interacting particle system describing two species: prey and predators. Prey undergo autocatalytic reproduction on empty sites of a lattice. Predators also reproduce autocatalytically at the expense of prey, as well as suffer spontaneous annihilations. The irreversible local rules of the model, involving two parameters, are inspired both in the Lotka-Volterra model and the contact process. In the stationary regime, the model shows three phases. The first one is associated to an absorbing state in which the lattice is completely covered by prey. The second one is characterized by finite values of the density of each species. As we tune the parameters values inside that phase, local oscillations in the population densities start to appear. The second phase is reached from the first one through a line of continuous kinetic phase transitions. The line belongs to the universality class of directed percolation in d+1 dimensions, except for its terminal point, which belongs to the universality class of ordinary percolation. The third phase corresponds to another absorbing state completely devoided of particles. The transition from the second to the third phase is continuous and also belongs to universality class of directed percolation in d+1 dimensions. The model has been studied by means of computer simulations as well as by using approximate analytical technics.
Borusas, Henrikas. "Mechaninių gaminių integruotos gamybos sistemos modelio sukūrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2008~D_20080929_150209-33461.
Full textThe practical realization of model theoretical bases to medium Lithuanian company X is carried out. Considered company in manufacturing business of small trucks components’ is involved. It applies the various metal profiles as materials and machining, welding and painting operations. The company business process was modeled, tested and validated. It works on the virtual prototypes at the early business conception stage. Main task of developed model in this stage is forecasting of manufacturing cost and decision making selecting suppliers and partners. The results and conclusions of work are presented.
VIDAL, JOSE T. "Desenvolvimento de um sistema opto-mecanico para micro usinagem com laser de fentossegundos." reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9563.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Ferreira, Luiz Fernando Vianna Faulhaber. "Mecânica dos fluidos como um sistema vinculado." Universidade Federal de Juiz de Fora (UFJF), 2014. https://repositorio.ufjf.br/jspui/handle/ufjf/6066.
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Nesta dissertação apresentamos um estudo em Dinâmica de Fluidos, em que foram discutidas as equações básicas como por exemplo a equação de Navier-Stokes e a equação da continuidade em suas formas diferenciais tradicionais. Apresentamos também uma analogia destas equações com as equações de Maxwell do eletromagnetismo. E tendo em vista esta analogia, as equações da dinâmica dos fluidos foram escritas em uma forma linear, análoga `a forma das equações de Maxwell. Com isso podemos obter uma formulação Lagrangiana e Hamiltoniana, o que permite estudar o sistema como um sistema vinculado aplicando então métodos de teoria quântica de campos. Inicialmente para o caso de um fluido incompressível usamos o método simplético para a obtenção dos comutadores. Por fim, apresentamos uma extensão da analogia entre fluidos incompressíveis e a equações de Maxwell, tratando agora de um fluido compressível. No caso de um fluido compressível fizemos o tratamento através do uso do calibre de Lorentz para proceder a quebra da simetria do modelo. E com isso ob-termos os comutadores através dos parênteses de Poisson.
In this dissertation was showed a study in fluids dynamic, where it was discussed the basic equations of fluids, for example, the Navier-Stokes equations and the continuity equations in differentials form and in the tensorial form. It was also presented an analogy between Maxwell equations and fluids equations. This analogy allows writing the equations of fluids in a linear form as the electromagnetism equations. Thus, using this analogy one can do a Lagrangian and a Hamiltonian formulation for fluids. Treating this system as constrained system and applying quantum field theory methods in the study of fluids dynamic. We first use a symplectic method to obtain the commutators for a compressible fluid. In this case, the commutators were obtained using the Lorentz gauge to broken the gauge symmetry.
Petkevičiūtė, Daiva. "Mechaninių virpesių sistemą aprašančių diferencialinių lygčių sprendinio reiškimas baigtine eksponenčių suma." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070816_142415-98558.
Full textThe aim of this work was to explore the possibilities of a new method, which gives an ability to approximate functions by a finite sum of exponential functions. This method was applied to the solutions of the concrete differential equations that describe the system of mechanical oscillations. One of the possible application areas of the system of oscillations presented in the paper is to use oscillations caused by the wind or water waves as a source of renewable energy. The action principles of such mechanisms are investigated using mathematical simulation before the real working model. The solutions of the sophisticated system of differential equations are obtained either in the form of power series or a set of points, depending of the solving method chosen. However, none of these forms is convenient for exploring properties of the solution. Therefore, we have a problem to approximate the solutions with linear formations of exponential functions. It is possible then to express the solutions as the linear formations of harmonics. It is demonstrated that a steady solution of the system can be expressed as a finite sum of exponential functions. Approximation errors vary depending on the distance between the points used, the function, which is being approximated, and the computation errors.
Junior, Milton Alexandre da Silva. "Transição quântico-clássica em sistemas com propensão coletiva." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-17052010-111535/.
Full textIn this thesis, we studied the behavior of quantum systems which in the classical limit may exhibit either regular or chaotic behavior. Our study was based on the dynamical characterization of the, chaotic or regular, behavior of these systems in the classical limit through the analysis of the structure of phase-space distributions functions. Particularly, we have applied this characterization tools to the study of the quantum-to-classical transition in a class quantum systems, that we called generally as systems with collective propensity, which have the important property of admitting, in a certain limit analogous to the thermodynamical limit, a description of their dynamics in terms of a low number of variables of collective nature. This property allows us to describe the dynamics of very complicated systems in terms of the dynamics of systems with few degrees of freedom. Besides, this allows us to study the classical limit of these systems concomitantly with the thermodynamical limit, avoiding in this way to deal with formal procedures associated with the limit h 0. Differently from the usual approaches, the one we employ in this thesis, based on the systemscollective propensity, allows for an implementation of a description in terms of the behavior of phase-space distribution functions for systems endowed with a discrete spectrum in a finite-dimensional space.
Vasques, Edson Jose. "Escoamentos em sistemas anulares : o mapas de velocidades." [s.n.], 1994. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264773.
Full textTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: O presente trabalho é um estudo sobre os escoamentos anulares, onde se destacam os mapas de velocidades para os sistema excêntricos. Estes mapas foram obtidos através de: (i) algoritmos que foram desenvolvidos utilizando as soluções de Snyder 8c Goldstein (1965) para o regime laminar e (ii) da técnica da inversa:o geométrica como apresentada por Ozgen & Tosun (1987) para os escoamentos laminares e turbulentos. Esta técnica transforma um sistema anular excêntrico em um sistema concêntrico, permitindo estender os poucos pontos disponíveis, experimentais ou de soluções analíticas, para abranger praticamente toda a área da secção transversal do escoamento. Foram utilizados como base de referência turbulento os resultados experimentais de Jonsson & Sparow (1966) . Dez sistemas anulares excêntricos foram selecionados. Cinco para cada regime de escoamento ... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: This work deals with annular flows in concentric and eccentric systems. For the latter, we highlight velocity maps. These maps were obtained from: (i) algorithms created by us, based on the SNYDER & GOLDSTEIN (1965) solutions for the laminar flow case and (ii) the geometric inversion technique as presented by OZGEN & TOSUN (1987) for laminar and turbulent flows. The Latter transforms an eccentric annulus system into a concentric system allowing thereafter to probe the complete flow area through a few available points which can be obtained either experimentally or via analytic solutions. We took JONSSON & SPARROW (1966)'s experimental data for velocities as starting point for our calculations for the turbulent case. Ten eccentric annuli systems were selected, five for each flow regime ... Note: The complete abstract is available with the full electronic digital thesis or dissertations
Doutorado
Doutor em Engenharia Mecânica
Andrade, João Pedro Jericó de. "Statistical Mechanics of Economic Systems." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-03012017-104524/.
Full textNesta tese, exploramos o potencial de ser usar técnicas de Mecânica Estatística para o estudo de sistemas econômicos, mostrando como tal abordagem pode contribuir significativamente ao permitir o estudo de sistemas complexos que exibem comportamentos ricos como transições de fase, criticalidade e fases vítreas, não encontradas normalmente em modelos econômicos tradicionais. Exemplificamos este potencial através de três problemas específicos: (i) um framework de Mecânica Estatística para lidar com consumidores irracionais, no qual a racionalidade é controlada pela temperatura do sistema, que define o tamanho dos desvios do estado de máxima utilidade. Mostramos que um consumidor irracional aumenta a atividade econômica ao mesmo tempo que diminui seu próprio bem estar; (ii) uma anáise usando Teoria da Informação de matrizes Input-Output de economias reais, mostrando que os métodos de agregação utilizados para construí-las provavelmente subestima a dependência das cadeias de produção em certos setores cruciais, com consequências importantes para a analíse destes dados; (iii) um modelo em que agentes com uma riqueza inicial distributida como lei de potências trocam aleatoriamente objetos com preços distintos. Mostramos que esta desigualdade inicial gera uma desigualdade ainda maior em dinheiro livre, reduzindo a liquidez total na economia e diminuindo a quantidade de trocas. Discutimos as consequências dos resultados destes três problemas, bem como sua relevância na perspectiva geral em Economia.
Pereira, Fábio de Toledo. "Reengenharia e evolução do visualizador e modelador do sistema Freeflow3D." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-30112011-100039/.
Full textPrograms for numerical simulation of fluid flow are inherently complex applications that involve multiple disciplines of computer science, mathematics and engineering. Usually, the simulation suite consists of the simulator itself, modelers (preprocessing) and viewers (post processing). The Freeflow3D is one of those environments, developed by the LCAD lab (Laboratório de Computação de Alto Desempenho) of the ICMC (Instituto de Ciências Matemáticas e de Computação), USP (Universidade de São Paulo). The simulator development is quite active with several researchers working on it. However, its viewer and modeler are virtually the same since their creation years ago, mainly because their evolution and maintenance over time have been hampered by its structure. This paper proposes an analysis of the Freeflow3D modeler and viewer to implement a software reengineering, proposing a new structure that changes their dynamics, modernizing their structure and making they particularly flexible for future developments and maintenance as well as adding new features that promote an improved user interface
Pérez, Palau Daniel. "Dynamical transport mechanisms in celestial mechanics and astrodynamics problems." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/362369.
Full textSouza, Bruno Lima de. "Estudo de emaranhamento num sistema de partículas carregadas em campo de onda plana quantizada." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-26032013-135243/.
Full textIn this work we study the properties of entanglement of the states of two quasi-photons of different frequencies, considering the approximation that the quasi-photon\'s vacuum is equal the photon\'s vacuum, in the case where we have no external field and in the case where we have an external, constant and homogeneous magnetic field. We study also the properties of entanglement of the quasi-photon\'s vacuum and of the states of two quasi-photons in the monochromatic case, without external field and with the quasi-photon\'s vacuum considered exactly.
Leckas, Darius. "Elektro mechaninių jutiklių taikymo navigacijai patalpų viduje tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140616_163238-21666.
Full textRecent technological improvements in micromachining process allows to produce smaller, cheaper and more accurate MEMS sensors. Better accuracy/size ratio increases MEMS sensors application field. One of most precise sensors looking for field is MEMS based indoor navigation system, which requires precise accelerometer/gyros, to ensure error free estimated position. Current gyros and accelerometers are much less precise than standard laser based gyros and bulk accelerometers. This work describes the main problems of using MEMS for inertial navigation and possible solutions, to minimize estimated position error. Research of MEMS application for indoor navigation. Master thesis for electronics engineer master degree. Vilnius Gediminas Technical University. Vilnius 2014 m.
Melo, Cássius Anderson Miquele de [UNESP]. "Princípio variacional de Schwinger e teoria quântica - aplicações à mecânica quântica quaterniônica e ao estudo de sistemas singulares." Universidade Estadual Paulista (UNESP), 2002. http://hdl.handle.net/11449/91853.
Full textFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Neste trabalho apresentamos um estudo detalhado da abordagem de Schwinger para a Mecânica Quântica, fazendo sua generalização para sistemas com escalares pertencentes ao conjunto dos quatérnions. Analisamos, em especial, a estrutura da Álgebra de Medida e sua relação com as propriedades físicas observáveis. Estudamos ainda o problema da liberdade de gauge relacionado à quantização do campo eletromagnético livre, e implementamos uma solução alternativa para este problema utilizando o Princípio Variacional de Schwinger, e o campo auxiliar B(x) introduzido por Nakanishi.
In this work we have presented a detailed study of the Schwinger s approach to the Quantum Mechanics, making its generalization for systems with scalars which belong to the quaternion set. In particular, we have analysed the structure of the Algebra of Measurement and its relation with the observable physical properties. We have also studied the problem of the gauge freedom related to the quantization of the free electromagnetic eld and implemented an alternative solution to this one employing the Schwinger s Variational Principle and the B- eld introduced by Nakanishi.
Gomes, João Tiago Assunção 1986. "Formalismos Gibbsianos para sistemas de spins unidimensionais." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/307025.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica
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Resumo: Exibir os estados de Gibbs e os estados de equilíbrios para certos sistemas de spins sobre reticulados é um problema de grande interesse para mecânica estatística. Com este intuito, apresentamos para o caso unidimensional dois formalismos existentes para tais sistemas: o formalismo DLR (enfoque mecânico-estatístico) e o formalismo SRB (enfoque dinamicista). Apesar das particularidades próprias aos contextos nos quais cada um dos formalismos se aplica, investigam-se aqui as relações existentes entre estes através da energia livre de Gibbs e da pressão topológica. Discute-se também o comportamento assintótico dos estados de Gibbs/equilíbrio quando levados ao congelamento do sistema. Tal fenômeno nos conduz ao estudo dos estados maximizantes via teoria de otimização ergódica. Ao fim, comparam-se algumas ideias da álgebra max/min-plus e o conceito de subação, as quais serão fundamentais para análise do comportamento assintótico da pressão topológica
Abstract: To exhibit Gibbs states and equilibrium states for certain kind of lattice spin systems is a problem with great interest for statistical mechanics. To that end, we introduce two existing formalisms for one-dimensional systems: DLR formalism (statistical-mechanical approach) and SRB formalism (dynamical-systems approach). In spite of their distinct applications, we analyse the relation between them through the notions of Gibbs free energy and topological pressure. We discuss also the asymptotic behaviour of Gibbs/equilibrium states when the system is frozen. This phenomenon leads us to the study of maximizing states in the context of ergodic optimization. Finally, we compare some ideas of max/min-plus algebra and the notion of sub-action, which will be essential to investigate the asymptotic behaviour of the topological pressure
Mestrado
Matematica
Mestre em Matemática
JONG, RUDOLF P. de. "Avaliacao de tubulacoes trincadas em sistemas primarios de reatores nucleares PWR." reponame:Repositório Institucional do IPEN, 2004. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11228.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
Andrade, João Pedro Jericó de. "Aplicações de mecânica estatística a sistemas sociais: interação e evolução cultural." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-07082012-154528/.
Full textIn this dissertation we apply statistical mechanics methods to two problems involving social interaction and cultural evolution. The first problem concerns the evolution and maintenance of altruistic cooperation. We discuss the two level Fisher-Wright mecanism proposed in [49] which deals with the question of evolutionary viability of altruistic behavior in a group structured population with migration, and is capable of circumventing certain limitations of other mecanisms proposed in the last century. We use this framework to analyse Boyd, Gintis and Bowles\' model [12] for the maintenance and proliferation of cooperation through altruistic punishment, showing that the two level Fisher-Wright process allows for a more robust and natural approach, showing altruism to be viable even at significantly high migration rates. The second problem deals with a model for explaining certain quantitative data obtained by Jonathan Haidt [32] in his Moral Foundation Theory. We study the agent based interaction model proposed in [16] in a scenario where the influcence graph consists of the Facebook social network to understand the network\'s influence in the results.
Pedrini, Rubens Antonio Amaral [UNESP]. "Desenvolvimento de sistema para sísmica up-hole em conjunto com o ensaio SPT." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/92971.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Este trabalho apresenta o sistema e metodologia para realização e interpretação de ensaios sísmicos up-role durante uma sondagem de simples reconhecimento (SPT). Este ensaio híbrido, conhecido também como S-SPT, incorpora a medida de velocidade de propagação de ondas de cisalhamento (Vs) ao ensaio SPT, visando uma melhor investigação do subsolo. A possibilidade de se medir, ao mesmo tempo e no mesmo furo, os valores de N do SPT e Vs, permitem calcular o módulo de cisalhamento máximo (Go), abrindo uma nova perspectiva para investigação de solos tropicais colapsíveis, a partir da relação Go/N, similar a relação Go/qc. O sistema é composto por um hardware (geofones, trigger e sistema de aquisição de dados) e softwares, um para registro dos sinais sísmicos e outro para sua interpretação. A metodologia de execução dos ensaios foi aperfeiçoada, a partir da realização de várias campanhas de ensaios de campo. Para a interpretação dos sinais e cálculo das velocidades foi elaborado um software, que possibilita definir os perfis de Vs sem a necessidade de outras ferramentas. Esse software possibilita o processamento e visualização dos registros, além de permitir aplicar um método específico para cálculo das velocidades de onda considerando a refração das ondas durante sua propagação através das diversas camadas do meio, conforme a Lei de Snell. Foram realizadas campanhas de ensaios S-SPT em um campo experimental localizado na cidade de Bauru, interior do estado de São Paulo, Brasil, para desenvolver o sistema e validar sua aplicação. Os resultados desses ensaios foram comparados com valores de Vs referência, determinados através de ensaios sísmicos down-hole, tipo SCPT. O ensaio S-SPT mostrou ser uma técnica interessante e aplicável, uma vez que a diferença entre os valores de Vs medidos com os de referência foi baixa, com um valor médio inferior a 10% para as áreas investigadas. Deste modo, pode ser
This work presents a system and methodology for performing and interpreting up-hole seismic tests together with the Standard Penetration Test (SPT). This hybrid test, also known as S-SPT, incorporates the measurements of shear waves velocity propagation (Vs) in the SPT, for a better site investigation. The possibility of measuring simultaneously in the same borehole, the N SPT and the Vs values which allows calculating the maximum shear modulus (Go), opens new perspectives for the investigation of collapsible tropical soils, from Go/N ratio, similar to Go/qc. The system consists of a hardware (geophones, trigger and data aquisition system) and software, one to record of the seismic signals and the other for its interpretation. The methodology for carrying out the tests was improved after several field trials. A software was developed for interpretation of records and calculating velocities, which allows to define the Vs profiles without the need of additional tools. This software enables processing and displaying records, and also allows applying a specific method for calculating velocities considering the waves refraction during their propagation through the various layers of the soil mass, according to the Snell's Law. The S-SPT campaigns were carried out in an experimental field located in the city of Bauru, São Paulo, Brazil, to develop the system and validate its application. The results of these tests were compared with Vs reference values, which were determined by the down-hole seismic test, SCPT type. The S-SPT test proved to be an interesting applicable technique, since the differences to the Vs reference values were small, wich and average lower than 10% for the investigated site. The S-SPT test can be considered as an option for determining the maximum shear modulus, with the advantage of being performed together with the most widely used test for site investigation, the SPT
Silva, Sandra Maria da. "Estudo da etapa de quimiexcitação do sistema peroxioxalato." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-03102016-162828/.
Full textThe phenomenon of chemiluminescence (CL) is one of the most fascinating demonstrations of chemical energy conversion into excitation energy. The most prominent example of this c1ass of reaction is the peroxyoxalate system showing emission quantum yields of around 30 %, comparable only to the 100 % efficiency bioluminescence systems. The peroxyoxalate system consists in the base catalyzed reaction of activated oxalate esters with hydrogen peroxide in the presence of polycondensed aromatic hydrocarbons with low oxidation potentials (Eox) and high fluorescence quantum yields, denominated activatars (ACT). The mechanism of this reaction is quite complex with various subsequent and parallel reaction steps prior to light emission. The crucial mechanistic step is the chemiexcitation step, where a highenergy intermediate (HEI), formed in former reaction steps, interacts with the ACT resulting in excited state formation and subsequent light emission. This interaction can be understood on the basis of the Chemically Initiated Electron Exchange (CIEEL) mechanism, which involves electron and back-electron transfer steps. A controversial point between various authors who study mechanistic aspects of the peroxyoxalate reaction is related to the nature of the high-energy intermediate (HEI) and different proposal for its structure (A - I) have been made. (See file). The main object of this work was to study the nature of the HEI and the chemiexcitation step in arder to obtain evidence with respect to the chemiexcitation mechanism in peroxyoxalate CL. For this purpose, the following approach was used: 1 - Synthesis and characterization of peracid intermediates of type
Martins, Andrey Gomes. "\"Evoluções discretas em sistemas quânticos com coordenadas não-comutativas\"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-07052007-144956/.
Full textWe study the nonrelativistic Quantum Mechanics of physical systems characterized F(Q) X \"A IND.\"teta\"\"(R X \"S POT.1\"), by the presence of an extra degree of freedom which does not commute with the time coordinate. In the language of Noncommutative Geometry, we deal with systems described by an algebra of the form F(Q) X \"A IND.\"teta\"\"(R X \"S POT.1\"),, where F(Q) is the algebra of functions over the usual con¯guration space \"Q\" e \"A IND.\"teta\"\"(R X\"S POT.1\") is a deformation of F(R X \"S POT.1\"), known as noncommutative cylinder. From a geometric viewpoint, the generators of the noncommutative cylinder correspond to the time coordinate and to an extra compact spatial coordinate, just like in Kaluza-Klein theories. We show that because of the noncommutativity between the time coordinate and the extra degree of freedom, the time evolution of systems described by F(Q) X \"A_t(R X S 1) is discretized. We develop the scattering theory for such systems, and verify the presence of a new e®ect: transitions from an in state with energy \"E IND.\"alfa\"\" and an out state with energy \"E IND.\"beta\"\" (diferente de \"E IND.\"alfa\"\") are now allowed, in contrast to the usual case. In fact, transitions take place whenever \"E IND.\"beta\" -\" E IND.\"alfa\" = 2\"pi\"/\"teta\"n,, with n \'PERTENCE A\'. The consequences of this result are investigated in the case of a one-dimensional delta barrier. Our analysis is based on the Born approximation for the transition matrix.
Johann, André Luiz. "Modelo preditivo fuzzy da mobilização do solo no sistema de plantio direto." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3141/tde-29062016-091351/.
Full textSoybean and corn crops account for the majority of Brazilian crop production, predominantly under no-till system. A high quality no-till seeding requires adequate furrow finishing to ensure a suitable environment for seed germination and emergence. Therefore, it is important to estimate furrow soil mobilization promoted by a chisel opener during seeding operation. Existing analytical models aim to represent soil mobilization in conventional tillage. As result, there are situations which the model cannot be applied, such as the case of chisel opener of no-till seeders. Under these situations, soil failure mechanism may change assuming a behavior not modeled by other studies yet. This research proposes a fuzzy model to represent these situations, taking advantage of knowledge obtained from soil mechanics theory and analysis of experimental data. In the proposed model, part of the rules describes situations not covered by the analytical model, which were formulated based on the estimation of possible mobilized soil areas. The fuzzy model was tested using data from experiments for two conditions of soil particle size (sandy and clay). The model simulated trends observed in the experimental data but overestimated observed values of area, which effect was much more intense on sandy soil experiment. The overestimation was due a sum of factors. One is the difference between experimental and modeled data, the first only consider the really mobilized soil, while the last consider the whole soil area, including the sheared but not mobilized area. Another factor was the effect of the straw cutting disc, which pre-shear the soil in front of the tool. In sandy soil experiment, observed values of soil disturbed area were lower than expected, overestimating the effect of fuzzy model, which was not a deficiency of the model.
Batista, Fabio Júnio Alves. "Sistema embarcado para detecção e determinação da posição dos picos de bragg em FBGs." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/1551.
Full textThis work developed a software to be embedded in an autonomous system based on ARM architecture, as the goal of detecting the peak position of a spectrum reflected by a Bragg grating written to optical fiber (FBG) and interrogated by the commercial Interrogator I-MON 512 E. The software was developed for the ARM architecture using the pcDuino platform which allows real-time monitoring and the data can be viewed in a graphical interface. For detecting the position of the peaks was applied to an algorithm that approximates the experimental data by a Gaussian function by the method of least squares. The system is characterized from the monitored temperature on the surface of a thermoelectric cell readings were made between 0°C and 100°C. Comparing the position of the Bragg peak registered with the system developed and the Ext_Evaluation software provided by the manufacturer of the interrogator I-MON it appears the average difference is approximately 0,010 nm. The mean difference in the position of the Bragg peak is less than 0.5 pm resolution is informed by the manufacturer of the interrogator I-MON. However, usually interested in changes in position of the Bragg peak instead of on absolute position in the spectrum. Thus, it can be concluded that the proposed algorithm is effective detecting the variation in position of Bragg peaks using FBG sensors.
Pedrini, Rubens Antonio Amaral. "Desenvolvimento de sistema para sísmica up-hole em conjunto com o ensaio SPT /." Bauru : [s.n.], 2012. http://hdl.handle.net/11449/92971.
Full textBanca: Otávio Coaracy Brasil Gandolfo
Banca: George de Paula Bernardes
Resumo: Este trabalho apresenta o sistema e metodologia para realização e interpretação de ensaios sísmicos up-role durante uma sondagem de simples reconhecimento (SPT). Este ensaio híbrido, conhecido também como S-SPT, incorpora a medida de velocidade de propagação de ondas de cisalhamento (Vs) ao ensaio SPT, visando uma melhor investigação do subsolo. A possibilidade de se medir, ao mesmo tempo e no mesmo furo, os valores de N do SPT e Vs, permitem calcular o módulo de cisalhamento máximo (Go), abrindo uma nova perspectiva para investigação de solos tropicais colapsíveis, a partir da relação Go/N, similar a relação Go/qc. O sistema é composto por um hardware (geofones, trigger e sistema de aquisição de dados) e softwares, um para registro dos sinais sísmicos e outro para sua interpretação. A metodologia de execução dos ensaios foi aperfeiçoada, a partir da realização de várias campanhas de ensaios de campo. Para a interpretação dos sinais e cálculo das velocidades foi elaborado um software, que possibilita definir os perfis de Vs sem a necessidade de outras ferramentas. Esse software possibilita o processamento e visualização dos registros, além de permitir aplicar um método específico para cálculo das velocidades de onda considerando a refração das ondas durante sua propagação através das diversas camadas do meio, conforme a Lei de Snell. Foram realizadas campanhas de ensaios S-SPT em um campo experimental localizado na cidade de Bauru, interior do estado de São Paulo, Brasil, para desenvolver o sistema e validar sua aplicação. Os resultados desses ensaios foram comparados com valores de Vs referência, determinados através de ensaios sísmicos down-hole, tipo SCPT. O ensaio S-SPT mostrou ser uma técnica interessante e aplicável, uma vez que a diferença entre os valores de Vs medidos com os de referência foi baixa, com um valor médio inferior a 10% para as áreas investigadas. Deste modo, pode ser
Abstract: This work presents a system and methodology for performing and interpreting up-hole seismic tests together with the Standard Penetration Test (SPT). This hybrid test, also known as S-SPT, incorporates the measurements of shear waves velocity propagation (Vs) in the SPT, for a better site investigation. The possibility of measuring simultaneously in the same borehole, the N SPT and the Vs values which allows calculating the maximum shear modulus (Go), opens new perspectives for the investigation of collapsible tropical soils, from Go/N ratio, similar to Go/qc. The system consists of a hardware (geophones, trigger and data aquisition system) and software, one to record of the seismic signals and the other for its interpretation. The methodology for carrying out the tests was improved after several field trials. A software was developed for interpretation of records and calculating velocities, which allows to define the Vs profiles without the need of additional tools. This software enables processing and displaying records, and also allows applying a specific method for calculating velocities considering the waves refraction during their propagation through the various layers of the soil mass, according to the Snell's Law. The S-SPT campaigns were carried out in an experimental field located in the city of Bauru, São Paulo, Brazil, to develop the system and validate its application. The results of these tests were compared with Vs reference values, which were determined by the down-hole seismic test, SCPT type. The S-SPT test proved to be an interesting applicable technique, since the differences to the Vs reference values were small, wich and average lower than 10% for the investigated site. The S-SPT test can be considered as an option for determining the maximum shear modulus, with the advantage of being performed together with the most widely used test for site investigation, the SPT
Mestre
Barbetti, Marcos Rogerio Sanches. "Estudo comparativo entre coxim hidraúlico e coxim elastomérico, aplicados ao sistema de apoio do motor automotivo." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/3/3149/tde-30122014-163747/.
Full textDue to strong competition inside of the automotive market, aspects as quality and cost become priority in the search of competitiveness. Several companies work in proposals seeking the cost reduction without quality loss. Several vehicles inside of Brazilian market use the hydraulic mount at their engine mount system. The initial proposal seeks the substitution of this type of mount by an elastomeric mount. Based on this proposal, we have this research that intends to present comparatively the behavior between the hydraulic mount and the elastomeric mount. Besides the researched bibliography, we accomplished the practical comparative study with physical parts evaluating as specifications used by automotive industries. We observed that the elastomeric mount presented substantial improvements since the seventies, offering good compromising between static stiffness and isolation vibration performance. The hydraulic mount presents high damping at low frequency range but its dynamic stiffness at high frequency is larger than elastomeric mount, but its performance at vibration isolation will depend of dynamic stiffness, damping coefficient and of the frequency range that it will be submitted. Due to the cost of the elastomeric mount to be about three times smaller than hydraulic mount cost, the elastomeric mount becomes great attraction to compose the engine mount system. Besides the cost, is evident that should be also evaluate the performance for the users comfort and new studies in specialized laboratories shall be accomplished.
Geraldes, Simão Manuel Morais. "Desenvolvimento e construção dum sistema interferométrico Shear baseado da shearography speckle para medição de deformações no plano." Master's thesis, Instituto Politécnico de Bragança, Escola Superior de Tecnologia e de Gestão, 2008. http://hdl.handle.net/10198/2065.
Full textContesini, Adriana Maria. "Posição sentada e função respiratória em dois sistemas cadeira-mesa diferentes." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/5/5163/tde-03012012-112841/.
Full textHuman posture is an important object of study in physiotherapy. Specially, the study of sitting posture considering that this is the most frequently body positioning adopted by man. It is known that this is a positioning influenced significantly by the furniture used. This dissertation had intended to examine the effects on pulmonary function of the postures induced by two different table-chair systems, featuring the seated posture and respiratory function in each furniture, correlating those postures found with performance on the pulmonary function test. To achieve this purpose, initially two systematic reviews were conducted: the first related to the theme \"The evolution of man and the sitting posture: bases for the physiotherapist\" whose goal was to enable understanding of the most common sequelae caused by different postures and understand the relationships of individuals with their environment, their work and with the social and cultural aspects involved in this relationship. The second review focused on the theme: \"Influence of sitting posture changes in respiratory function review of the literature\", through which it was carried out a literature review to describe the knowledge produced about respiratory function changes in different postures, especially in a sitting posture, noting that although the pulmonary function changes are most significant in individuals with lung and heart diseases, and the elderly, even in healthy individuals changes function tests may exceed the variation of values considered normal for a given position. Throughout this study, considering that the sitting posture is the body positioning most frequently adopted by man and is influenced by the furniture used, fifteen volunteers were assessed using two Chair-table systems, one considered as a conventional system (the system) and an experimental one (System B). Postural assessment was carried out by means of photogrammetry in each furniture. These images were analyzed, estimating the average position of individuals in each furniture. Pulmonary evaluation consisted of performing spirometry. The values found were analysed by checking the means obtained in each posture. Postural and respiratory data were compared by checking whether the various positions adopted by the participants resulted in changes in the spirometric values. As a result it was found that the conventional chair led two different postural patterns, being one of them presented joint angles similar to system B, with similar spirometric results. The second group had body angles in accordance with the expected ones and spirometric results significantly lower in Fev1, Fev1/FVC and FEFmáx. System B differed from orthostatic posture only in FEFmáx, suggesting a similarity of situation. In this way, it can be concluded that the furniture used in sitting posture influences significantly respiratory function. In this study the experimental furniture proved a tool capable of benefiting the respiratory function in sitting posture, and raise the possibility of options when using conventional furniture to benefit people in special conditions such as pregnant women, obese and people with chronic lung diseases
Silva, Cristhiano André Gamarano Duarte Carneiro. "Sobre a catálise em sistemas quânticos." Universidade Federal de Juiz de Fora (UFJF), 2013. https://repositorio.ufjf.br/jspui/handle/ufjf/3246.
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Deixado de lado durante anos na Mecânica Quântica, o Emaranhamento é visto hoje em dia como uma fonte, um recurso a ser utilizado. Cabendo a cada pesquisador aproveita-lo da melhor forma possível. Usado para gerar algoritmos mais eficientes, teleportar estados quânticos, e realizar tarefas antes impossíveis, o emaranhamento pode ser um recurso ainda mais estranho. Basta ver o fenômeno da catálise, onde o emaranhamento extra utilizado não é consumido. Aqui nosso objetivo é estudar um pouco mais sobre a catálise em sistemas quânticos e obter uma maneira de dizer quais estados são catalisadores em potencial.
Left aside for years in quantum theory, the entanglement is today a source, a resource to be utilised. Each researcher should use it of the best way possible. Used to generate faster algorithms, to teleport states and perform tasks before impossibles, the entanglement may be a more strange source. Just watch the catalysis phenomenon, where the extra entanglement utilized is not consumed. Here our goal is studying just a little bit of catalysis in quantum systems and get a way to say which states are potential catalysts.
Santos, Leonardo Sioufi Fagundes dos. "Correlações e interferência de sistemas atômicos de Bose-Einstein frios." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-17102007-161038/.
Full textThis work consists of a theoretical study of the coexistance of coupled atomic Bose-Einstein condensates. These mixed condensates can consist of atoms of the same element in different hyperfine internal states. A different situation is that in which an atom in one internal state can ocupate different single particle external states. The similarities and differences between mixed Bose-Einstein condensates involving internal and external states will be analysed carefully. Only in the Bose-Hubbard approximation the external states can be treated like internal states. Condensates involving two or more species will be studied with in a Thomas- Fermi\'s approximation with coherent states. This approximation involves in discarding of the Hamiltonian the kinetic energy term. A number of analytical results are given for the case in which the different channel scatering lenghts are equal to each other. This condition is which well approximated in condensates involving many internal states. Beside some results will also be given for situations where the scatering lenghts for different species vanishes. This condiction is verified for the Bose-Hubbard approximation to externally mixed condensates. The principal goal of this calculations is to study the role of relative phase between the wave functions in the stationary solutions and in the time evolution of the systems.
Gerardin, Rodrigo Ceccatto. "Modelo dinamico do sistema pistão-biela-manivela com mancais hidrodinamicos." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263457.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: Atualmente, devido as exigências comerciais e técnicas, os motores de combustão interna operam com pressões de combustão cada vez mais altas. Ao mesmo tempo, deve-se otimizar a operação de todo sistema e a forma dos componentes levando-se em conta a melhor performance e redução de peso. Para um melhor entendimento do comportamento dinâmico de um motor de multi cilindros, é necessário verificar a cinemática e a dinâmica para apenas um cilindro como feito neste trabalho. O foco principal deste trabalho é desenvolver um modelo matemático para determinar as distribuições de pressão e as forças atuantes nos mancais hidrodinâmicos para um cilindro de um motor de combustão interna. Um modelo dinâmico do sistema de pistão-biela-manivela é apresentado e permite calcular as forças dinâmicas e folgas no mancal principal, olhais maior e menor da biela derivados da pressão de combustão. O modelo matemático do mancal hidrodinâmico radial é oriundo da equação de Reynolds e resolvido utilizando o Método de Elementos Finitos. O sistema dinâmico não-linear é resolvido utilizando o método iterativo de Newton-Raphson para cada passo de integração no tempo
Abstract: Due to the current commercial and technical requirements, the internal combustion engines must operate under higher pressures. It is also necessary to optimize the system operation and the shape of the components aiming at increasing the performance and weight reducing. For a better understanding of the dynamical behavior of a multi-cylinder engine, it is necessary to verify the kinematics and dynamics for just one cylinder, as considered in this work. The main focus of this work is the development of a mathematical model to determine the pressure distributions and the hydrodynamic bearing forces for one cylinder internal combustion engine. The dynamical model of the piston-conrod-crank system is presented and allows the calculation of the dynamic forces and clearances obtained from the combustion pressure for the main, big-end and small-end bearings. The mathematical model of the hydrodynamic bearing comes from the Reynolds equation and is solved by the Finite Element Method. The non-linear dynamic system is solved by the iterative Newton-Rhapson method for each time integration step
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica
Pontin, Luiz Francisco. "Sobre a Equivalência dos Modelos Antiferromagnético Diluído e Ferromagnético em Campo Aleatório: Versão Hierárquica." Universidade de São Paulo, 1990. http://www.teses.usp.br/teses/disponiveis/43/43132/tde-10122013-172327/.
Full textWe are presenting a hierarchical version of Ising modal to show an equivalence between the ferromagnetic model in a random magnetic field and dilute antiferromagnetic modal in a uniform magnetic field. The equivalence is based on the fact that a dilute antiferromagnetic in a uniform magnetic field generates under a renormalization group transformation a random magnetic field. We also verify that when we do not take into account contours inside contours the models analyzed show phase transition for dimension d greater than or equal to two. The method used consist of combination of Peierls, Imry and Ma arguments and the Renormalization Group Transformation, which in the hierarchical approach becomes an exact process.
Assumpção, Maíra Seabra de. "Valores de referência para sistema de oscilometria de impulso em crianças saudáveis." Universidade do Estado de Santa Catarina, 2014. http://tede.udesc.br/handle/handle/1831.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior
The impulse oscillometry system (IOS) is considered a non-invasive method for assessing respiratory mechanics which has been increasingly used in the child population. Currently there are no reference equations for IOS healthy Brazilian children. The aim of this study was to determine reference equations/values for the parameters of impulse oscillometry system in healthy children. Characterized as an observational cross-sectional analytical study, it has been conducted with healthy schoolchildren 6- to 14-years of age from educational institutions in Florianópolis/SC - Brazil. The children were characterized as healthy by questionnaire on asthma and allergies in childhood (International Study of Asthma and Allergies in Childhood - ISAAC) and a recall of structured health, in addition to spirometry. Biometric data of weight, height, body mass index and body surface area were also evaluated. All participants were subjected to analysis of respiratory mechanics with impulse oscilometry Jaeger (Master Screen IOS, Erich Jaeger, Germany®), recorded three tests, with data acquisition for at least 20 seconds. The verification of the normality of the data was performed using the Kolmogorov-Smirnov test and using the Pearson Correlation Test between the predictor variables of height, age and weight and the oscillometric variables resistances at 5 and 20 Hz (R5 and R20), reactance (X5), the respiratory 5 hertz (Z5), resonant frequency (Fres), and reactance area (AX) impedance, relations were identified. For the development of equations, models from the analyzes of simple and multiple linear regression were considered through the software SPSS version 20.0 for Windows. As a result, after recruiting 864 children, it was considered for final analysis 123 individuals healthy with mean of the boys 10.02±2.41 years in boys and 9.98±2.48years in girls. Correlations were found between oscillometric dependent variable and the predictor variable, the height identified with greater predictive power in the equations developed for boys in all parameters of oscillometry with a mean value of R2 adjusted=55.8%. Already in girls, age had a greater influence on the parameters of Fres (R2adjusted= 40.1%) and AX (R2adjusted = 48.8%). Given the above, reference equations for the female and the male were developed, the height the most influential predictor variable in most of the IOS parameters in the pediatric population studied.
O sistema de oscilometria de impulso (IOS) é considerado um método não invasivo de avaliação da mecânica respiratória que vem sendo crescentemente utilizado na população infantil. Atualmente não existem equações de referência do IOS para crianças saudáveis brasileiras. O objetivo do presente estudo foi determinar valores de equações/valores de referência para parâmetros do sistema de oscilometria de impulso em crianças saudáveis. Caracterizado como um estudo analítico observacional transversal, este foi realizado com escolares saudáveis de seis a 14 anos de idade de instituições de ensino da Grande Florianópolis/SC - Brasil. Os quais foram caracterizados como hígidos pelo questionário sobre asma e alergias na infância (International Study of Asthma and Allergies in Childhood ISAAC) e um recordatório estruturado sobre saúde, além do exame de espirometria. Também foram avaliados dados biométricos de peso, altura, índice de massa corporal e área de superfície corporal. Todos os participantes foram submetidos à análise da mecânica respiratória com oscilometro de impulso Jaeger (Master Screen IOS, Erich Jaeger, Germany®), com registro de três exames, com aquisição de dados por no mínimo 20 segundos. A verificação da normalidade dos dados foi feita pelo teste Kolmogorov-Smirnov e, através do teste de correlação de Pearson foram identificadas as relações entre as variáveis preditoras de altura, idade e peso e as variáveis oscilométricas de resistências a 5 e 20 hertz (R5 e R20), reatância (X5), impedância respiratória à 5 hertz (Z5), frequência de ressonância (Fres), e área da reatância (AX). Para o desenvolvimento das equações foram considerados os modelos resultantes das análises de regressão linear simples e múltipla através do software SPSS® versão 20.0 para Windows®. Como resultado, após o recrutamento de 864 crianças, considerou-se para análise final 123 indivíduos saudáveis com média de 10.02±2.41 anos em meninos e 9.98±2.48 anos em meninas. Foram constatadas correlações entre as variáveis oscilométricas dependentes e as preditoras, sendo a altura identificada com maior poder preditivo nas equações desenvolvidas para meninos em todos os parâmetros da oscilometria com valor médio de R2ajustado=55.8%. Já nas meninas, a idade teve maior influência nos parâmetros de Fres (R2ajustado=40.1%) e AX (R2ajustado=48.8%). Diante do exposto, foram desenvolvidas equações de referência para o sexo feminino e o masculino, sendo a altura a variável preditora mais influente na maioria dos parâmetros do IOS na população infantil estudada.
Nenad, Poznanović. "Prilog kinematičkoj sintezi mehanizama u sistemima oslanjanja motornih vozila." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2016. https://www.cris.uns.ac.rs/record.jsf?recordId=101537&source=NDLTD&language=en.
Full textThis paper is focused on the design of lever mechanisms used in systems for elastic vehicle suspension.The lever mechanisms used for wheel guidance are tasked with accomplishing a mobile connection between the wheel and the support structure that allows the wheel a roughly vertical motion relative to the vehicle body and receives the active and reactive forces and torque originating from the interaction between the wheel and the ground.A simple, universal method for the optimal synthesis of mechanisms used in vehicle support systems is defined, one that doesn’t require extensive preparation or adjustments for specific conditions. The basic characteristics of the proposed method are: accuracy and practical applicability of the method; simplicity and universality of the whole synthesis process, insured by adopting the differential evolution algorythm for the optimization method; robustness of the method and the lack of need for preparation and adjustments to the different synthesis peoblems; by implementing the method in the universal mathematical program Mathcad, the calculation elements (input, equations, comments, sketches, diagrams and numerical resuts) are all presented and accessible in one place.The application of the developed method is demonstrated on charachetirstic problems of the optimal synthesis of vehicle support mechanisms. The problems are set up so that the motion of the wheel support is known – it is generated by a mechanism with a known configuration. In this kind of setting, where one is sure the given motion of the wheel support can be accomplished, a series of numerical tests was performed with multiple repetitions of the synthesis method using different initial values of the unknown construction parameters randomly chosen from wide intervals. The results of these experiments have shown that for each set of initial values, the developed method resulted in a mechanism that accomplished the required motion with very slight deviations, too small to be of any practical importance.
Paolini, Fabio. "Dinâmica gaussiana de sistemas atômicos de Bose-Einstein frios." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-24042009-145044/.
Full textWe study low-lying excitations of a spinless, homogeneous bose gas, with repulsive interaction, at zero temperature, in terms of a gaussian mean field approximation. The dynamical equations of this approximation have been linearized in small displacements from the well known static Hartree-Fock-Bogoliubov solution. We obtain a gapped continous band of excitations above a discrete branch with phonon behavior at large wavelengths. We also discuss the allowed forms of excitations and conclude that restrictions exist for the allowed deviations of the general set of gaussian mean field parameters, when they are generated in first orders by infinitesimal unitary transformations.
Bemfica, Fábio Sperotto. "Dinâmica quântica de sistemas não-comutativos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/17438.
Full textThis work is concerned with the global consistency of the quantum dynamics of noncommutative systems. Our point of departure is the theory of constrained systems, since it provides a uni ed description of the classical and quantum dynamics for the models under investigation. We then analise the problem concerned with the su cient conditions for the existence of the Born series and unitarity and turn, afterwards, into studying the functional quantization of non-commutative systems. The compatibility between the operator and the functional approaches is established in full generality. Subsequently, the generalized Weyl transform of index α is used to implement the time-slice de nition of the phase space path integral yielding the Feynman kernel in the case of noncommutative quantum mechanics. As expected, this representation for the Feynman kernel is not unique but labeled by the real parameter α. We succeed in proving that the α-dependent contributions disappear at the limit where the time slice goes to zero. This proof of consistency turns out to be intricate because the Hamiltonian necessarily involves products of noncommuting operators. The antisymmetry of the matrix parameterizing the noncommutativity plays a key role in the cancelation mechanism of the α-dependent terms. Finally, we study the embedding procedure formulated by Batalin, Fradkin and Tyutin (BFT) which enables one to transform these noncommutative systems into an Abelian gauge theory exhibiting only rst class constraints. The appropriateness of the BFT embedding, as implemented in this work, is veri ed by showing that there exists a one to one mapping linking the second class model with the gauge invariant sector of the gauge theory. As is known, the functional quantization of a gauge theory calls for the elimination of its gauge freedom. Then, we have at our disposal an in nite set of alternative descriptions for noncommutative quantum mechanics, one for each gauge. We study the relevant features of this in nite set of correspondences. The functional quantization of the gauge theory is explicitly performed for two di erent gauges and the results compared with that corresponding to the second class system. Within the operator framework the gauge theory is quantized by using Dirac's method.
Meirelles, Paula Sampaio. "Mecânica estatística de sistemas complexos: crescimento de tumores com diferenciação e mobilidade celular." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21102010-130821/.
Full textCancer (neoplasia) is one of the most dangerous diseases and one of the main cause of mortality around the world. Despite the great advances in diagnosis and treatment, it still represents a huge challenge to researchers of many areas. Recently there was a strinking discovery that may give rise to a complete different paradigm in the understanding of how cancer starts and grows, with eventually profound consequences in the forms of treatment. It is related to the ending of adult stem cells in tumors, and its possible role in the birth and growth of them. We propose in this work a mathematical model that takes into account the presence of cells with the properties of (a) self renewal, (b) differentiation and (c) mobility, characteristics of stem cells. The model developed is a probabilistic cellular automaton with asynchronous update set in a grid. Each element of the grid may be empty or contain a tumor cell. There are two types of cells: the cells labeled as type 2 are those associated with cancer stem cells and those labeled as type 1 are differentiated cells only capable of reproducing. The reproduction rate of each cell is defined as a function of its neighborhood and its type. Different rates of reproduction have been used in the simulations, and type 2 cells may differentiate and some motility. Our simulation results show how the motility of cells 2 and the reproduction rates of both types of cells influence the morphological patterns of tumor. We have also investigated a possible phase transition that may be related to metastasis. This phase transition represents something of great biological interest because metastasis is the most important mechanism that leads to death. We will compare our results with experimental data from collaborators Nascimento TL et al [1] in UNIFESP-Escola Paulista de Medicina.
Bergamo, José Vinícius Zapte. "Teoria de funções elípticas e aplicações em soluções de sistemas periódicos em mecânica." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/154055.
Full textRejected by Ana Paula Santulo Custódio de Medeiros null (asantulo@rc.unesp.br), reason: A ficha catalográfica deve ser solicitada à biblioteca, pelo site: http://ib.rc.unesp.br/#!/biblioteca/biblioteca/ , clicar em Serviços, Ficha Catalográfica. A ficha catalográfica só pode ser elaborada por um bibliotecário. De acordo com a Resolução CFB nº 184/2017 de 29/09/2017 – na Ficha catalográfica deve constar o nome do Bibliotecário/CRB, e ser elaborada de acordo com as normas vigentes segundo à AACR2. É proibido perante a lei (Art. 297 – Código Penal) qualquer alteração documental, sem autorização do Bibliotecário responsável. DA FALSIDADE DOCUMENTAL: (I) FALSIDADE DE DOCUMENTO PUBLICO ART. 297: Falsificar, no todo ou em parte, documento publico, ou alterar documento publico verdadeiro: Pena – reclusão, de dois a seis anos, e multa. DOCUMENTO PUBLICO: é aquele elaborado por funcionário publico, de acordo com as formalidades, e desempenho de suas funções. Art. 232, CPP - Consideram-se documentos quaisquer escritos, instrumentos ou papéis, públicos ou particulares. Obs: O arquivo da dissertação também está com várias páginas em branco. Favor removê-las. on 2018-05-21T16:44:27Z (GMT)
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É bem conhecido que em Mecânica Analítica muitos problemas integráveis não tem primitivas escritas em forma de funções elementares, tais como: corpo rígido assimétrico em rotação livre; pêndulo esférico, entre outros. O uso de funções elípticas faz-se necessário para se buscar soluções analíticas desses problemas. Neste trabalho, faremos primeiramente uma revisão da teoria dessas funções adotando como referência alguns textos clássicos. Feito isso, estudaremos a formulação de problemas de dinâmica, a saber o pêndulo simples e o pião simétrico. Por fim, com as integrais desses problemas em mãos, iremos determinar suas soluções com o uso das funções elípticas de Jacobi e Weierstrass.
It is well known that in Analytical Mechanics many simple integrable problems cannot be written in terms of elementary functions, such as: rigid asymmetrical body in free rotation, spherical pendulum, among others. The use of elliptic functions becomes necessary in order to obtain analytical solutions of these problems. In this work, we present a review of the theory of these functions accordingly to some classical texts. In the sequence, we study two problems of mechanics: the simple pendulum and the symmetrical top. Finally, we will determine the solutions to these problems using of the Jacobi and Weierstrass elliptic functions.
Jácome, Samyr Silva Bezerra. "Aspectos dinâmicos e estruturais em modelos de redes para sistemas complexos." reponame:Repositório Institucional da UFC, 2009. http://www.repositorio.ufc.br/handle/riufc/12893.
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In this thesis we study systems where some form of disorder or non-homogeneity has a significant role at the complexity of the structural building or of the dynamics regulation of the system. First, we study the dynamics of Boolean networks, where the rules to update the state of the nodes are randomly chosen and control the global behavior of the system. At the critical threshold, and near to it, we propose that the transition to the critical regime can be characterized by the divergence of the relaxation time Tr. Based on simple scaling arguments, we show that the cumulative probability distribution of Tr decays as a power-law , with exponent iqual -1, for the annealed model at the critical region. Then, we study a novel method for network decomposition, which we apply to scale-free networks, that have the broad degree distribution as a fundamental feature. This method consists in a simultaneous and iterative remotion of groups of nodes with degree K until there are no more nodes with this degree in the network. Thus, we define new variables that characterize the process of decomposition and we obtain a set of well define exponents and parameters. From the behavior of these variables we can see, through some mathematical manipulations, that our method is self-consistent, serving as a useful tool for the study of the structural features of the network. At last, we study the backbones of the percolation cluster, where we use a network model with layers arranged in a disorderly way to represent some kind of anisotropy resistance to the percolation. Our numerical results indicate a break at the universality class on the fractal dimension and on the mass distribution of the backbones.
Nesta tese estudaremos sistemas onde alguma forma de desordem ou não-homogeneidade tem um importante papel na complexidade da formação estrutural ou da regulagem dinâmica do sistema. Primeiramente estudaremos a dinâmica das redes Booleanas, onde as regras de atualização escolhidas aleatoriamente controlam o comportamento global do sistema. Na condição crítica e próximo dela, propomos que a transição para o regime crítico pode ser caracterizado pela divergência do tempo de relaxação Tr. Baseados em simples argumentos de escalonamento, mostramos, além de outros resultados, que a probabilidade acumulativa da distribuição de Tr decai como uma lei de potência, com o expoente igual a -1, para o modelo annealed na região crítica. Em seguida estudamos um novo método de decomposição de redes aplicado às redes livres de escalas, onde a ampla distribuição de conectividade é um aspecto fundamental. O método consiste basicamente na retirada simultânea e iterativa de grupos de vértices com um determinado grau K de conectividade até que não haja mais sítios com este mesmo grau de conectividade na rede. Deste modo, definimos algumas variáveis que caractarizam o processo de decomposição e obtemos uma série de expoentes e parâmetros bem definidos. A partir do comportamento destas variáveis pudemos constatar por meio de algumas manipulações matemáticas que nosso método é auto-consistente, servindo como ótima ferramenta para estudo dos aspectos estruturais de uma rede. Por fim, estudamos os backbones, onde utilizamos um modelo de rede em que a desordem está no arranjo aleatório de camadas fáceis e difíceis à percolação. Os resultados numéricos indicam a quebra na classe de universalidade da geometria fractal e da distribuição de tamanhos de massa do backbones e também um comportamento assintótico da dimensão fractal no limite de grandes valores de massa e/ou anisotropia.
Dias, Débora Regina. "Resistência à compressão não confinada de misturas de solo-cimento visando à aplicação do sistema de estabilização Dry-Mix." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258580.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: Este trabalho vem contribuir com a técnica de tratamento de solos moles por meio do sistema de estabilização Dry-Mix, analisando parâmetros de resistência à compressão não confinada de corpos-de-prova, devidamente preparados com misturas plásticas de solo mole, aglomerante (cimento Portland) e água, em laboratório. O solo utilizado era oriundo da região da Baixada Santista, localizada no Estado de São Paulo. Duas diferentes dosagens de cimento, 100 e 200 kg de cimento por m³ de solo, além de dois diferentes tipos de cimento CP III e CP V, foram utilizadas neste estudo. Os corpos-deprova foram ensaiados à compressão não confinada nas idades de cura de 7, 28, 90 e 180 dias, e submetidos aos ensaios de ultrassom, durante 28 dias. As dosagens inferiores a 100 kg de cimento por m³ de solo apresentaram resultados de resistência à compressão não confinada inferiores a 200 kN/m², não sendo recomendadas para o tratamento Dry-Mix. Os módulos de elasticidade apresentaram valores crescentes até a idade de 28 dias, indicando perda da rigidez após essa idade de cura. Nos ensaios de ultrassom, foram observados resultados significativos somente para os corpos-de-prova com a dosagem de 200 kg de cimento por m³ de solo. Os resultados de resistência à compressão simples foram submetidos a uma análise estatística, na qual as médias dos resultados foram comparadas com o tipo de cimento, a dosagem, a quantidade de turfa e a idade dos corpos-de-prova, utilizando o teste de Tukey, ao nível de 95% de probabilidade estatística. No geral, os melhores resultados ficaram por conta do cimento CP V - ARI, e com a dosagem de 200 kg de cimento por metro cúbico de solo
Abstract: This work focuses on contributing with the soft soil treatment through the use of Dry-Mix stabilization system, analyzing the parameters of unconfined compressive strength tests performed in specimens properly prepared with plastic mixtures of soft soil, binder (Portland cement) and water, in laboratory. The soil used was from Santos city, located in the state of São Paulo. Two different amounts of cement, 100 and 200 kg per cubic meter of soil, as well as two different kinds of cement: CP III and CP V cement were used in this study. The tests were conducted under unconfined compressive strength at ages 7, 28, 90 and 180 days and underwent ultrasound tests for 28 days. The amounts below 100 kg of cement per m³ presented unconfined compressive strength results under 200 kN/m², which are not recommended for Dry-Mix treatment. The modules of elasticity presented increasing numbers up to the age of 28 days, indicating rigidity loss after this age. In the ultrasound tests, significant results were observed only in the test with the amount of 200 kg of cement per soil m³. The simple unconfined compressive strength results underwent a statistic analysis, in which the result averages were compared according to the type of cement and amount, as well as the amount of peat and the tests ages, by using the Tukey's range test at 95% of statistical probability. In general, the best results were presented by the CP V - ARI cement, with the amount of 200 kg cement per m³ of soil
Mestrado
Geotecnia
Mestre em Engenharia Civil
Moraes, Fernando de Haro [UNESP]. "Comportamento dinâmico não-linear de um sistema mecânico com vibrações associadas a uma transição brusca na rigidez." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/97144.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Nas aplicações em engenharia existem várias situações onde é necessário o uso de vibrações em certas partes de um sistema mecânico, criadas a partir de transição brusca de um parâmetro do sistema, como por exemplo, em máquinas perfuratrizes de solo na exploração de petróleo onde a condição de impacto na interação-rolha facilita a penetração no solo. Os sistemas mecânicos submetidos a esse forma de excitação são chamados em geral de mecanismos tipo Vibro-Impacto. Nesta dissertação, faz-se a análise da dinâmica de um sistema mecânico Vibro-Impacto de dois graus de liberdade composto por dois blocos de massas diferentes acoplados por uma rigidez (mola) de dois estágios. Dois modelos não-lineares foram utilizados para representar o sistema estudado: o primeiro é excitado de maneira ideal, sob a forma de uma força harmônica e o segundo, de maneira não-ideal sob a forma de um rotor desbalanceado acionado por um motor elétrico de corrente contínua. A dinâmica do sistema é modelada considerando duas situações distintas: sem a condição de impacto e com a condição de impacto, de acordo com a relação entre o deslocamento e a folga no sistema. Foram analisados os resultados das simulações numéricas através dos históricos no tempo, retratos de fase, diagramas de bifurcações, mapas de Poincaré e espectros de frequencias. Observaram-se as velocidades de avanço do sistema, as taxas de transferência de energia, e as forças durante as transições bruscas da rigidez (condição tipo impacto) entre as massas, determinando-se as faixas dos parâmetros com comportamentos periódicos e caóticos assim como a ocorrência do Efeito Sommerfeld. A partir dos resultados obtidos foi possível concluir que o mecanismo tipo Vibro-Impacto analisado possui maior velocidade de avanço e maior força em determinada frequencia de excitação onde o movimento apresenta-se no regime caótico
In engineering aplications there are several situations in which it is necessary to use vibrations in certain elements of a mechanical system, created with an abrupt transition from one system parameter, such as soil drilling machines in oil exploration where the impact condition on the drill-rock interaction enhances penetration into soil. Mechanical systems subjected to this form of excitation are called in general mechanisms of vibro-impact type. This dissertation makes the analysis of the dynamics of a the dynamics of a Vibro-Impact mechanical system of two degrees of freedom comprised of two blocks with different masses coupled by a two-stage stiffness (spring). Two nonlinear models are used to represent the studied system: the first uses an ideal excitation in the form of a harmonic force, and the second uses a non-ideal excitation in the form of a unbalanced rotor driven by a direct current electric motor. The dynamics of the system is modeled by considering two different situations: without impact and with impact, according to the relationship between the displacement and the gap in the system. The results of numerical simulations were analyzed with the time histories, phase portraits, bifurcation diagram, Poincaré map and spectra of frequencies. Velocities of the system, the rate of energy transfer, and forces during abrupt transitions in stiffneess (impact type condition) between the masses were observed, determining the ranges of parameters with periodic and chaotic behavior as well as the occurrence of the Sommerfeld effect. From the results it was possible to conclude that the analysed Vibro-Impact mechanism has a larger progress velocity and larger forces in a given excitation frequency where the movement presents itself in the chaotic regime
Moraes, Fernando de Haro. "Comportamento dinâmico não-linear de um sistema mecânico com vibrações associadas a uma transição brusca na rigidez /." Bauru : [s.n.], 2012. http://hdl.handle.net/11449/97144.
Full textCoorientador: José Manoel Balthazar
Banca: Angelo Marcelo Tusset
Banca: Edson Antonio Capello Sousa
Resumo: Nas aplicações em engenharia existem várias situações onde é necessário o uso de vibrações em certas partes de um sistema mecânico, criadas a partir de transição brusca de um parâmetro do sistema, como por exemplo, em máquinas perfuratrizes de solo na exploração de petróleo onde a condição de impacto na interação-rolha facilita a penetração no solo. Os sistemas mecânicos submetidos a esse forma de excitação são chamados em geral de mecanismos tipo Vibro-Impacto. Nesta dissertação, faz-se a análise da dinâmica de um sistema mecânico Vibro-Impacto de dois graus de liberdade composto por dois blocos de massas diferentes acoplados por uma rigidez (mola) de dois estágios. Dois modelos não-lineares foram utilizados para representar o sistema estudado: o primeiro é excitado de maneira ideal, sob a forma de uma força harmônica e o segundo, de maneira não-ideal sob a forma de um rotor desbalanceado acionado por um motor elétrico de corrente contínua. A dinâmica do sistema é modelada considerando duas situações distintas: sem a condição de impacto e com a condição de impacto, de acordo com a relação entre o deslocamento e a folga no sistema. Foram analisados os resultados das simulações numéricas através dos históricos no tempo, retratos de fase, diagramas de bifurcações, mapas de Poincaré e espectros de frequencias. Observaram-se as velocidades de avanço do sistema, as taxas de transferência de energia, e as forças durante as transições bruscas da rigidez (condição tipo impacto) entre as massas, determinando-se as faixas dos parâmetros com comportamentos periódicos e caóticos assim como a ocorrência do Efeito Sommerfeld. A partir dos resultados obtidos foi possível concluir que o mecanismo tipo Vibro-Impacto analisado possui maior velocidade de avanço e maior força em determinada frequencia de excitação onde o movimento apresenta-se no regime caótico
Abstract: In engineering aplications there are several situations in which it is necessary to use vibrations in certain elements of a mechanical system, created with an abrupt transition from one system parameter, such as soil drilling machines in oil exploration where the impact condition on the drill-rock interaction enhances penetration into soil. Mechanical systems subjected to this form of excitation are called in general mechanisms of vibro-impact type. This dissertation makes the analysis of the dynamics of a the dynamics of a Vibro-Impact mechanical system of two degrees of freedom comprised of two blocks with different masses coupled by a two-stage stiffness (spring). Two nonlinear models are used to represent the studied system: the first uses an ideal excitation in the form of a harmonic force, and the second uses a non-ideal excitation in the form of a unbalanced rotor driven by a direct current electric motor. The dynamics of the system is modeled by considering two different situations: without impact and with impact, according to the relationship between the displacement and the gap in the system. The results of numerical simulations were analyzed with the time histories, phase portraits, bifurcation diagram, Poincaré map and spectra of frequencies. Velocities of the system, the rate of energy transfer, and forces during abrupt transitions in stiffneess (impact type condition) between the masses were observed, determining the ranges of parameters with periodic and chaotic behavior as well as the occurrence of the Sommerfeld effect. From the results it was possible to conclude that the analysed Vibro-Impact mechanism has a larger progress velocity and larger forces in a given excitation frequency where the movement presents itself in the chaotic regime
Mestre
Lebre, Rui André Cruz. "Accounting mechanism for shared medical imaging repositories." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23615.
Full textA imagem médica em formato digital é um elemento presente nas mais variadas instituições prestadoras de cuidados de saúde, afirmando-se como um imprescindível elemento de suporte ao diagnóstico e terapêutica médica. Nesta área, os formatos e processos de armazenamento e transmissão são definidos pela norma internacional DICOM. Um ficheiro deste tipo contempla, para além da imagem (ou vídeo), um conjunto de meta-dados que incluem informação dos pacientes, dados técnicos relativos ao estudo, dose de radiação, relatório clínico, etc. Um dos maiores problemas associados aos repositórios de imagem médica está relacionado com a grande quantidade de dados produzidos que impõe desafios acrescidos ao armazenamento e transporte da informação, em particular em cenários distribuídos e de grande produção de estudos imagiológicos. Esta dissertação tem como objetivo estudar e explorar soluções que permitam a integração do conceito de pertença e controlo de acesso em arquivos de imagem médica, possibilitando a centralização de múltiplas instâncias de arquivos. A solução desenvolvida permite associar permissões a recursos e delegação a terceiras entidades. Foi desenvolvida uma interface programática de gestão da solução proposta, disponibilizada através de web services, com a capacidade de criação, leitura, atualização e remoção de todos os componentes resultantes da arquitetura.
The production of medical images in digital format has been growing in the most varied health care providers, representing at this moment an important and indispensable element for supporting medical decisions. In medical imaging area, the formats and transmission processes are defined by the international DICOM standard. A file in this format contains image pixel data but also a set of metadata, including information about the patient, technical data related to the study, dose of radiation, clinical report, etc. One of the biggest problems associated with medical imaging repositories is related to the large amount of data produced that poses additional challenges to the transport and archive of information, particularly in distributed environments and laboratories with huge volume of examinations. This dissertation aims to study and explore solutions for the integration of ownership concept and access control over medical imaging resources, making possible the centralization of multiple instances of repositories. The proposed solution allows the association of permissions to repository resources and delegation of rights to third entities. It was developed a programmatic interface for management of proposed services, made available through web services, with the ability to create, read, update and remove all components resulting from the architecture.
Sauerwein, Ricardo Andreas. "Método de Monte Carlo para Sistemas Quânticos." Universidade de São Paulo, 1995. http://www.teses.usp.br/teses/disponiveis/43/43133/tde-13122013-180031/.
Full textThe ground state properties of the antiferromagnetic quantum Heisenberg model with spin-112 defined on a square lattice and on a cubic lattice with spatial anisotropy are investigated through a new Monte Carlo method, based on the estimation of the largest eigenvalue of a matrix with nonnegative elements. The ground state energy and the staggered magnetization of these systems are calculated in relatively large lattices with up to 24 x 24 sites for the square lattices and 8 x 8 x 8 sites for cubic lattices. The method developped can also be used as a new algorithm for the direct determination of the entropy of Ising spin systems through ordinary Monte Car10 simulations. By using this method we calculate the entropy of the Ising antiferromagnetic in the presence of a magnetic field in the triangular and face centered cubic lattices.