Este trabalho visa a avaliar os efeitos dinâmicos em vigas esbeltas semi-infinitas com contato unilateral em apoio elástico sob flexão composta, e sua possível aplicação a dutos flexíveis de extração de petróleo offshore em configuração de catenária (Steel Catenary Risers) provocados por esforços de movimento da plataforma. O estudo se desenvolve com formulação de vigas semi-infinitas em duas dimensões (2D) com suporte unilateral elástico, considerando-se inicialmente apenas efeito de flexão, à qual se aplica o método das múltiplas escalas (MME) para obtenção dos modos de vibração, e posteriormente o método das variedades invariantes (MVI) para recuperação das relações modais entre as coordenadas generalizadas e as variáveis modais. Trata-se, a seguir, da formulação do problema com consideração da tração, tanto estática como dinâmica, e a projeção da equação de movimento completa segundo os modos obtidos no problema da flexão simples, para obtenção do modelo de ordem reduzida com efeito de tração, que permitiu estudar este último qualitativa e quantitativamente. A formulação inicial teve como ponto de partida a utilização de mudanças de variáveis que permitiu a transformação do problema de condições móveis em condições fixas de contorno, propiciando caracterizar o movimento vertical da viga na solução analítica do problema de vibrações livres, até o limite possível, para depois utilizar técnicas de integração numérica na solução do problema de vibrações forçadas. A motivação para estudo de tais efeitos está ligada à importância indiscutível que tem para a indústria petrolífera e para a economia mundial, além do crescente papel deste segmento em termos nacionais. A descoberta do Campo de Tupi, na Bacia de Santos, que representa a maior reserva de óleo e gás do País, alavancou pesquisas para extração de petróleo em águas ultra-profundas (profundidades da ordem de 2.500m) (fonte: www.petrobras.com.br), além da necessidade já estabelecida de maiores pesquisas em águas profundas (profundidades que podem chegar a 2.000m). Considere-se também a motivação da própria Petrobrás, cujo intuito é ter capacidade de extrair 4,5 milhões de barris por dia até 2020. Tal capacidade de produção deve exigir 45 sistemas de produção, sendo que cada sistema de produção necessita de 4 a 5 barcos de apoio, totalizando assim 200 barcos operando em 2020 (Fonte: O Estado de São Paulo, Ano 131, Nº 42786, Coluna Celso Ming). Apesar da crescente pesquisa em fontes alternativas de energia, a demanda não só por óleo e gás, mas também pela utilização de polímeros e componentes plásticos, ainda sustentará a extração de petróleo por no mínimo algumas décadas. Além disso, técnicas melhores na fixação de carbono (técnicas naturais e artificiais para seqüestro de carbono), permitem sonhar que a utilização de petróleo, desde a sua queima até a produção de material sintético possa se tornar cada vez menos impactante para o meio ambiente. / This work aims at analyzing the dynamical effects in slender reticulated beams on elastic support with unilateral contact under combined axial force and bending, and the possibility of its association with steel catenary risers connected to offshore structures, caused by movement of the platform. The study is developed based on 2D semi-infinite beams on unilateral elastic support, initially considering only bending effects, to which the multiple scales method (MSM) is applied to obtain vibration modes, and thereafter the invariant manifold method (IMM) to obtain the modal relationships between the generalized coordinates and the modal variables. It follows the formulation of the problem considering tension effects, both from static and dynamical sources, and the projection of the full equation of motion with respect to the vibration modes from the first formulation considering only bending effects, which allows us to obtain the reduced order model with tension effects, and its application to steel catenary risers (SCR). The starting point for the mathematical formulation is a variable transformation, which allows us to change a free boundary into a fixed boundary one. It is then possible to obtain the free-vibration analytical solution, as far as possible, and then use numerical integration schemes to obtain the forced vibration time responses. As motivation, we can firstly mention the unquestionable role of the oil and gas industry for the world economy, besides its increasing market share within the national economy. The discovery of the Tupi Field, in the Santos Basin, which represents the biggest oil and gas reserve of the Country, gave impulse to investments and research in all fields associated to the oil and gas area, in ultra deep water (depth around 2.500m), besides the well known need of research in deep water (depth around 2.000m). In spite of the growing research on alternative sources of energy, the world still demands not only oil and gas, but also polymers and plastic components, and this will still be the scenario for the next decades. Besides that, the increasing of knowledge in carbon sequestration may keep up the use of oil and gas for some more decades, hopefully with less environment impact.

Submitted by Larissa Vitoria Cardoso Cusielo (larissavitoria@id.uff.br) on 2017-09-05T16:50:14Z No. of bitstreams: 3 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) FABIO BARROSO_Dissertação Versão Final..pdf: 2901244 bytes, checksum: 054b14cc8ec478fa55c530aa86c1f89c (MD5) Fábio Barroso - Produto Educacional - Versão Final.pdf: 1815635 bytes, checksum: f6783be97ebf7fec3d1e0d8d04e5348c (MD5) / Rejected by Biblioteca do Aterrado BAVR (bavr@ndc.uff.br), reason: Titulo em caixa alto on 2017-09-05T19:18:30Z (GMT) / Submitted by Larissa Vitoria Cardoso Cusielo (larissavitoria@id.uff.br) on 2017-09-05T19:49:50Z No. of bitstreams: 3 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) FABIO BARROSO_Dissertação Versão Final..pdf: 2901244 bytes, checksum: 054b14cc8ec478fa55c530aa86c1f89c (MD5) Fábio Barroso - Produto Educacional - Versão Final.pdf: 1815635 bytes, checksum: f6783be97ebf7fec3d1e0d8d04e5348c (MD5) / Approved for entry into archive by Biblioteca do Aterrado BAVR (bavr@ndc.uff.br) on 2017-09-27T22:43:12Z (GMT) No. of bitstreams: 3 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) FABIO BARROSO_Dissertação Versão Final..pdf: 2901244 bytes, checksum: 054b14cc8ec478fa55c530aa86c1f89c (MD5) Fábio Barroso - Produto Educacional - Versão Final.pdf: 1815635 bytes, checksum: f6783be97ebf7fec3d1e0d8d04e5348c (MD5) / Made available in DSpace on 2017-09-27T22:43:12Z (GMT). No. of bitstreams: 3 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) FABIO BARROSO_Dissertação Versão Final..pdf: 2901244 bytes, checksum: 054b14cc8ec478fa55c530aa86c1f89c (MD5) Fábio Barroso - Produto Educacional - Versão Final.pdf: 1815635 bytes, checksum: f6783be97ebf7fec3d1e0d8d04e5348c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Ciências Exatas. Programa de Pós-Graduação em Ensino de Física. Volta Redonda, RJ / Esta dissertação apresenta um produto educacional que visa à aplicação do método gráfico das coordenadas criado pelo professor de Física Pierre Henri Lucie em uma aula sobre lentes delgadas esféricas de ensino médio, em alternativa ao método geométrico usado na obtenção da equação dos pontos conjugados. A aula está fundamentada nas teorias da aprendizagem significativa e no uso das tecnologias de informação e comunicação com o intuito de introduzir o tópico de forma mais dinâmica. Através da aplicação de um roteiro para o estudante, revisamos o conteúdo de formação de imagens em uma lente convergente utilizando o banco óptico virtual do aplicativo PhET para conectar o novo conteúdo com elementos já conhecidos pelos estudantes, ou seja, os chamados subsunsores. Na etapa seguinte, os alunos usam o software gratuito GeoGebra ou o papel milimetrado juntamente com os pontos obtidos no PhET e, desta forma, constroem a relação que leva a equação dos pontos conjugados de Gauss através do método gráfico das coordenadas. Como uma etapa complementar, um questionário é utilizado para que o aluno possa demonstrar se o conteúdo foi assimilado através desta atividade. Além disso, o relato das atividades realizadas e o depoimento de um professor mostraram o entusiasmo dos alunos assim como o interesse em utilizar as ferramentas disponibilizadas para concluir o trabalho proposto. Portanto, é possível concluir que o trabalho descrito nesta dissertação não só auxiliou na introdução do tópico, mas também levou a uma melhoria na inserção do na inserção do assunto em sala de aula. / This dissertation presents an educational product that aims to apply the graphical method of coordinates created by Professor of Physics Pierre Henri Lucie in a high school class upon spherical thin lenses as an alternative to the geometrical method used to obtain the equation of conjugate points. The class is based on the theories of meaningful learning and the use of information and communication technologies in order to introduce the topic in a dynamic way. By applying a class script for the student, we reviewed the content of image formation for a converging lens by using the virtual optical bench of the PhET application to connect the new content with elements already known by the students, i.e., the so-called subsunsores. At the next stage, the students use the free software, known as GeoGebra, or the graph paper with the points obtained in the PhET in order to get a relation that leads to the equation of conjugate points of Gauss by applying the graphical method of coordinates. As a complementary step, a questionnaire is used to confirm that the content was assimilated by the students through this activity. Furthermore, activity’s report and the testimony of a teacher showed the students' enthusiasm as well as the interest in using the tools available to complete the proposed assignment. Therefore, it is possible to conclude that the work described in this thesis not only improved the introduction of the topic, but also led to an improvement of the subject insertion in the classroom.

La thèse constitue une juxtaposition de plusieurs contributions originales à lélaboration et lanalyse de modèles numériques capables de décrire une vaste gamme découlements à surface libre ainsi que les phénomènes de transport associés. Deux axes principaux sous-tendent les recherches entreprises. Il sagit, dune part, dune contribution à létude de modèles visant à reproduire adéquatement les interactions du fluide avec divers constituants transportés, tels que de lair entraîné, un polluant ou des sédiments. Cette phase du travail inclut également la caractérisation et la prédiction du comportement de lécoulement en présence dune topographie mobile ou érodable, y compris dans le cas dun barrage en remblai subissant une surverse. Dautre part, partant du constat quune modélisation fidèle des processus de transport, notamment hydrosédimentaires, passe inévitablement par un raffinement du calcul hydrodynamique proprement dit, une partie des travaux effectués dans le cadre de cette thèse est spécifiquement orientée vers un enrichissement de la connaissance des champs hydrodynamiques au sein du modèle.

The research objective of this dissertation is to create and demonstrate methods for parameterizing the Pareto frontiers of continuous multi-attribute design problems using barycentric coordinates, and in doing so, to enable intuitive exploration of optimal trade spaces. This work is enabled by two observations about Pareto frontiers that have not been previously addressed in the engineering design literature. First, the observation that the mapping between non-dominated designs and Pareto efficient response vectors is a bijection almost everywhere suggests that points on the Pareto frontier can be inverted to find their corresponding design variable vectors. Second, the observation that certain common classes of Pareto frontiers are topologically equivalent to simplices suggests that a barycentric coordinate system will be more useful for parameterizing the frontier than the Cartesian coordinate systems typically used to parameterize the design and objective spaces. By defining such a coordinate system, the design problem may be reformulated from y = f(x) to (y,x) = g(p) where x is a vector of design variables, y is a vector of attributes and p is a vector of barycentric coordinates. Exploration of the design problem using p as the independent variables has the following desirable properties: 1) Every vector p corresponds to a particular Pareto efficient design, and every Pareto efficient design corresponds to a particular vector p. 2) The number of p-coordinates is equal to the number of attributes regardless of the number of design variables. 3) Each attribute y_i has a corresponding coordinate p_i such that increasing the value of p_i corresponds to a motion along the Pareto frontier that improves y_i monotonically. The primary contribution of this work is the development of three methods for forming a barycentric coordinate system on the Pareto frontier, two of which are entirely original. The first method, named "non-domination level coordinates," constructs a coordinate system based on the (k-1)-attribute non-domination levels of a discretely sampled Pareto frontier. The second method is based on a modification to an existing "normal boundary intersection" multi-objective optimizer that adaptively redistributes its search basepoints in order to sample from the entire frontier uniformly. The weights associated with each basepoint can then serve as a coordinate system on the frontier. The third method, named "Pareto simplex self-organizing maps" uses a modified a self-organizing map training algorithm with a barycentric-grid node topology to iteratively conform a coordinate grid to the sampled Pareto frontier.

Optical parameters measured via absorption spectroscopy and high-resolution fluorescence spectroscopy were used to characterize dissolved organic matter (DOM) in the springshed of Kings Bay, a spring-fed estuary located on Florida's Springs Coast. Over the past 40 years, springs supplying groundwater to Kings Bay have shown an increase in nitrate concentration. The overall goal of this project was to fingerprint wells and spring sites with elevated nitrogen concentrations using CDOM optical properties and establish relationships between nutrient and optical parameters. Samples were obtained from various sites: springs, Kings Bay surface (KBS), wells, coastal waters in and at the mouth of Crystal River (Coast) and lakes and rivers (LNR), during dry and wet seasons. The relationships between the environmental parameters and traditional optical parameters which provide insight into source characteristics were analyzed. Excitation emission matrix spectroscopy (EEMS) provided information about the concentration and chemical nature of organic matter in the study area. CDOM optical properties combined with salinity clearly separated the sources of fixed nitrogen in the Bay. Northern springs with elevated dissolved inorganic nitrogen (DIN) concentration had lower salinities and showed a presence of protein peaks. CDOM concentration was negatively correlated with total nitrogen (TN) and DIN, which suggests that these are subjected to anthropogenic influences. Humic peaks dominated the composition of the southern springs. CDOM concentrations were much higher than in the northern springs and there was a positive correlation between CDOM and both TN and DIN. These findings suggest that the fixed nitrogen in the southern springs is naturally occurring organic matter and the low concentrations may partially be a result of subsurface mixing of saltwater and freshwater in the aquifer. Thus, hypothesis testing showed that there was a significant difference between northern and southern springs Hypothesis testing also showed that there is a significant and unexpected positive relationship between CDOM and salinity studying Kings Bay, which is due to the low CDOM concentration in the springs discharging fresh water. This unique dataset also determined that the intercept of the mixing line was significantly different form zero. This indicates that CDOM is present and detectable at very low concentrations. Parallel Factor Analysis (PARAFAC) was used to evaluate CDOM composition from excitation emission matrix spectra (EEMs) and five components were identified: two humic, two marine humic, and one protein-like. The marine-like components, peak M, were produced in the marine environment and in meteoric groundwater. The study found a unique groundwater marker for coastal regions. Northern Kings Bay sites were characterized by a protein-like component, which has been associated with wastewater. Additional optical and environmental parameters were used in discriminate analysis, which successfully identified the CDOM markers for both natural and anthropogenic sources of nutrients in the environment. It is vital to improve the analysis of water, nutrients, and carbon from groundwater discharge into the coastal zone. Elevated DIN concentrations in groundwater are a widespread problem in Florida and over the past 30 years many spring waters have shown an increase in DIN concentrations. Nutrient discharge into delicate coastal areas can lead to ecological concerns. Investigating CDOM and nutrient distribution together can be a beneficial tool that can help differentiate sources from riverine/lacustrine, estuarine, marine, groundwater, and sewage impacted categories.

No description available.

Wireless Sensor Networks (WSNs) are composed of a large number of battery-powered sensor nodes that have the ability to sense the physical environment, compute the obtained information and communicate using the radio interfaces. Because sensor nodes are generally deployed on a large and wild area, they are powered by embedded battery. And it is difficult to change or recharge the battery, thus to reduce the energy consumption when sensors and protocols are designed is very important and can extend the lifetime of WSNs. So sensor nodes transmit packets with a lower transmission power (e.g. OdBm). With this transmission power, a packet can only be transmitted dozens of meters away. Therefore, when a sensor detects an event, a packet is sent in a multi-hop, ad-hoc manner (without fixed infrastructure and each sensor is able to relay the packet) to the sink (specific node which gathers information and reacts to the network situation). In this thesis, we first give an elaborate state of the art of WSNs. Then the impacts of duty-cycle and unreliable links or the performances of routing layer are analyzed. Based on the analytical results, we then propose three new simple yet effective methods to construct virtual coordinates under unreliable links in WSNs. By further taking the duty-cycle and real-time constraints into consideration we propose two cross-layer forwarding protocols which can have a greater delivery ratio and satisfy the deadline requirements. In order to have protocols for the WSNs that have dynamic topology, we then propose a robust forwarding protocol which can adapt its parameters when the topology changes. At last, we conclude this thesis and give some perspectives.

Submitted by Dilene Paulo (dilene.fatima@ufcg.edu.br) on 2018-02-07T13:41:46Z No. of bitstreams: 1 VERA SOLANGE DE OLIVEIRA FARIAS – TESE PPGEP 2011.pdf: 7179434 bytes, checksum: 4a30c9a95f4a089e00fa550fbf1b42b8 (MD5) / Made available in DSpace on 2018-02-07T13:41:46Z (GMT). No. of bitstreams: 1 VERA SOLANGE DE OLIVEIRA FARIAS – TESE PPGEP 2011.pdf: 7179434 bytes, checksum: 4a30c9a95f4a089e00fa550fbf1b42b8 (MD5) Previous issue date: 2011-04-29 / CNPq / Este trabalho apresenta a solução numérica da equação de difusão tridimensional em regime transiente, para um domínio arbitrário. Para atingir os objetivos, a equação de difusão foi discretizada usando coordenadas generalizadas via método dos volumes finitos com uma formulação totalmente implícita, para condições de contorno de equilíbrio e convectiva. Para cada passo no tempo, o sistema de equações obtido para uma dada malha estruturada foi resolvido pelo método de Gauss-Seidel. O código computacional foi desenvolvido em FORTRAN, usando o estúdio CVF 6.6.0, na plataforma Windows Vista. A solução proposta foi validada usando soluções analíticas e numéricas da equação de difusão para várias geometrias, permitindo validar malhas ortogonais e não-ortogonais. A análise e comparação dos resultados mostraram que a solução proposta forneceu resultados coerentes para todos os casos investigados. O código computacional desenvolvido foi aplicado na simulação, a partir de dados experimentais da secagem de telhas cerâmicas para as seguintes condições experimentais: temperaturas de 55,6 °C, 69,7 °C, 82,7 °C e 98,6 °C e teor de umidade inicial variando de 0,2345 até 0,2405 (b.s.). A simulação tornou possível determinar o coeficiente de difusão efetivo em função da razão de umidade e da temperatura do ar de secagem e também o valor do coeficiente de transferência convectivo de massa correspondente para cada temperatura. / This work presents a three-dimensional numerical solution for the diffusion equation in transient state, in an arbitrary domain. The diffusion equation was discretized using the finite volume method with a fully implicit formulation and generalized coordinates, for the equilibrium and convective boundary condition. For each time step, the system of equations obtained for a given structured mesh was solved by the Gauss-Seidel method. A computational code in FORTRAN, using the CFV 6.6.0 Studio, in a Windows Vista platform was developed. The proposed solution was validated by analytical and numerical solutions of the diffusion equation for several geometries. The geometries tested enabled to validate both orthogonal and non-orthogonal meshes. The analysis and comparison of the results showed that the proposed solution provides correct results for all cases investigated. The developed computational code was applied in the simulation, using experimental data of the drying of ceramic roof tiles, for the following experimental conditions: temperature from 55.6; 69.7; 82.7; 72.8 and 98.7 °C, initial moisture content from 0.2345 up to 0.2405 (d.b.). The simulation makes it possible to determine an expression for the diffusion coefficient as a function of the moisture content and temperature of the drying air, and also the value of the convective mass transfer coefficient corresponding to each temperature.

Made available in DSpace on 2014-12-17T14:55:09Z (GMT). No. of bitstreams: 1 JoseSASS.pdf: 1375081 bytes, checksum: 1561bdbc1ba8feb7671abf9ebca84641 (MD5) Previous issue date: 2007-04-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work proposes a method to determine the depth of objects in a scene using a combination between stereo vision and self-calibration techniques. Determining the rel- ative distance between visualized objects and a robot, with a stereo head, it is possible to navigate in unknown environments. Stereo vision techniques supply a depth measure by the combination of two or more images from the same scene. To achieve a depth estimates of the in scene objects a reconstruction of this scene geometry is necessary. For such reconstruction the relationship between the three-dimensional world coordi- nates and the two-dimensional images coordinates is necessary. Through the achievement of the cameras intrinsic parameters it is possible to make this coordinates systems relationship. These parameters can be gotten through geometric camera calibration, which, generally is made by a correlation between image characteristics of a calibration pattern with know dimensions. The cameras self-calibration allows the achievement of their intrinsic parameters without using a known calibration pattern, being possible their calculation and alteration during the displacement of the robot in an unknown environment. In this work a self-calibration method based in the three-dimensional polar coordinates to represent image features is presented. This representation is determined by the relationship between images features and horizontal and vertical opening cameras angles. Using the polar coordinates it is possible to geometrically reconstruct the scene. Through the proposed techniques combination it is possible to calculate a scene objects depth estimate, allowing the robot navigation in an unknown environment / Este trabalho prop?e um m?todo para determinar a profundidade de objetos em cena utilizando uma combina??o das t?cnicas de vis?o est?reo e autocalibra??o. Determinando a dist?ncia relativa entre objetos visualizados e um rob? m?vel, dotado de uma cabe?a est?reo, ? poss?vel efetuar sua navega??o em ambientes desconhecidos. As t?cnicas de vis?o est?reo fornecem uma medida de profundidade a partir da combina??o de duas ou mais imagens de uma mesma cena. Para a obten??o de estimativas da profundidade dos objetos presentes nesta cena ? necess?rio uma reconstru??o da geometria da mesma. Para tal reconstru??o ? necess?rio o relacionamento das coordenadas tridimensionais do mundo com as coordenadas bidimensionais das imagens. Atrav?s da obten??o dos par?metros intr?nsecos das c?meras ? poss?vel fazer o relacionamento entre os sistemas de coordenadas. Estes par?metros podem ser obtidos atrav?s da calibra??o geom?trica das c?meras, a qual ? geralmente feita atrav?s da visualiza??o de um objeto padr?o de calibra??o com dimens?es conhecidas. A autocalibra??o das c?meras permite a obten??o dos par?metros intr?nsecos das mesmas sem a utiliza??o de um padr?o conhecido de calibra??o, sendo poss?vel a obten??o e a altera??o destes durante o deslocamento do rob? m?vel em um ambiente desconhecido. ? apresentado neste trabalho um m?todo de autocalibra??o baseado na representa??o de caracter?sticas da imagem por coordenadas polares tridimensionais. Estas s?o determinadas relacionando-se caracter?sticas das imagens com os ?ngulos de abertura horizontal e vertical das c?meras. Utilizando-se estas coordenadas polares ? poss?vel efetuar uma reconstru??o geom?trica da cena de forma precisa. Atrav?s desta combina??o das t?cnicas proposta ? poss?vel obter-se uma estimativa da profundidade de objetos cena, permitindo a navega??o de um rob? m?vel aut?nomo em um ambiente desconhecido

In my diploma thesis I have created the updated version of water sources and pumping sites for fire equipment in the Písek district. I acquired large volumes of data by a detailed physical inspection of possible water sources in all villages in the Písek district. In my thesis I have mentioned water sources only in those villages that are classified into fire protection units, category II and III. The complete summary of all water sources and water pumping sites is on the attached CD. The data contain the name of the village, type of water source, GPS coordinates, additional information about the water source and any additional notes regarding repairs, distances from the village, etc. Photo documentation and the map section were produced for each water source. In many villages, there are hydrant networks which, in those villages where there is no water source, can have a substantial effect on fire safety. The thesis also includes the list of all hydrant networks in the Pisek district, including the owners and operators. The thesis can be used for the Operating and Information Centre of the Fire Brigade for the South Bohemian region which, for the demand for water for rescue and liquidation can send the unit directly to the water source according to the ascertained data. For some water sources, below the table in the note, there may be corrections or improvements that lead to a better use of these sources. The thesis monitors the existing status of the water and pumping sites for fire equipment in the Pisek district. I compared the acquired data with data from South Bohemian Region Regulation No.4/2003 at 2.12.2003. It results from the compared data that permanent updating and communication on the part of the municipalities with the Fire Brigade is necessary. In many places, water sources are closed and new water points originate with the possibility to pump this basic and main extinguishing agent.