Made available in DSpace on 2014-12-17T14:58:12Z (GMT). No. of bitstreams: 1 KarilanyDC.pdf: 1404746 bytes, checksum: 75321c91ff10021c5b9665530a1b4f3d (MD5) Previous issue date: 2006-05-19 / The topology optimization problem characterize and determine the optimum distribution of material into the domain. In other words, after the definition of the boundary conditions in a pre-established domain, the problem is how to distribute the material to solve the minimization problem. The objective of this work is to propose a competitive formulation for optimum structural topologies determination in 3D problems and able to provide high-resolution layouts. The procedure combines the Galerkin Finite Elements Method with the optimization method, looking for the best material distribution along the fixed domain of project. The layout topology optimization method is based on the material approach, proposed by Bendsoe & Kikuchi (1988), and considers a homogenized constitutive equation that depends only on the relative density of the material. The finite element used for the approach is a four nodes tetrahedron with a selective integration scheme, which interpolate not only the components of the displacement field but also the relative density field. The proposed procedure consists in the solution of a sequence of layout optimization problems applied to compliance minimization problems and mass minimization problems under local stress constraint. The microstructure used in this procedure was the SIMP (Solid Isotropic Material with Penalty). The approach reduces considerably the computational cost, showing to be efficient and robust. The results provided a well defined structural layout, with a sharpness distribution of the material and a boundary condition definition. The layout quality was proporcional to the medium size of the element and a considerable reduction of the project variables was observed due to the tetrahedrycal element / O problema de otimiza??o topol?gica consiste na defini??o do leiaute estrutural pela da distribui??o ?tima de material no espa?o de projeto. Em outras palavras, ap?s serem definidas as condi??es de contorno num dom?nio de projeto pr?-estabelecido, o problema ? como distribuir o material de modo a solucionar o problema de minimiza??o. O objetivo deste trabalho ? propor uma formula??o para a determina??o de topologias estruturais ?timas, que seja competitiva para utiliza??o em problemas 3D e capaz de proporcionar leiautes de alta defini??o. O procedimento combina o M?todo de Elementos Finitos de Galerkin com o m?todo de otimiza??o, buscando a melhor distribui??o de material ao longo do dom?nio fixo de projeto. O m?todo de otimiza??o de leiaute empregado ? baseado na abordagem material, proposta por Bendsoe & Kikuchi (1988), que considera uma equa??o constitutiva homogeneizada dependente apenas da densidade relativa do material. O elemento finito utilizado para a aproxima??o ? o tetra?drico de quatro n?s, com um esquema de integra??o seletiva, que interpola n?o s? as componentes do campo de deslocamento como tamb?m o campo de densidade relativa. O processo proposto consiste na solu??o de uma seq??ncia de problemas de otimiza??o e ? aplicado a problemas de minimiza??o da flexibilidade (atendendo a um limite de volume material) e da massa (satisfazendo um crit?rio de tens?o) em estruturas tridimensionais. A microestrutura utilizada para a descri??o das propriedades materiais ? do tipo SIMP (Solid Isotropic Material with Penalty). A abordagem reduz consideravelmente o custo computacional, mostrando ser efetiva e promissora. Os resultados proporcionaram um leiaute estrutural definido, com n?tida distribui??o do material e defini??o do contorno, com qualidade proporcional ao tamanho m?dio do elemento da malha em quest?o, assim como uma consider?vel redu??o no total de vari?veis de projeto, devido ? utiliza??o do elemento finito empregado

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-17T19:02:40Z No. of bitstreams: 1 ClaudioAndresCallejasOlguin_TESE.pdf: 2208703 bytes, checksum: 0e72fd38176ce63ab4ad6ea3333dc84c (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-17T20:07:54Z (GMT) No. of bitstreams: 1 ClaudioAndresCallejasOlguin_TESE.pdf: 2208703 bytes, checksum: 0e72fd38176ce63ab4ad6ea3333dc84c (MD5) / Made available in DSpace on 2017-03-17T20:07:55Z (GMT). No. of bitstreams: 1 ClaudioAndresCallejasOlguin_TESE.pdf: 2208703 bytes, checksum: 0e72fd38176ce63ab4ad6ea3333dc84c (MD5) Previous issue date: 2016-07-29 / O conjunto de fun??es totais comput?veis somente tem sido estudado topologicamente como um subespa?o de um espa?o de Baire. Onde a topologia deste espa?o de Baire ? a topologia induzida de uma topologia de Scott para as fun??es parciais (n?o necessariamente comput?veis). Nesta tese constr?i-se uma topologia original no conjunto de ?ndices das fun??es totais comput?veis e demonstra-se que ela n?o ? homeomorfa com o subespa?o do espa?o de Baire que foi mencionado. H? um subconjunto indecid?vel importante no conjunto de fun??es totais comput?veis chamado ?o conjunto de fun??es comput?veis regulares?, que recebe aten??o especial nesta tese. Com a finalidade de fazer um estudo topol?gico deste conjunto constr?i-se todo um aparato te?rico. Ap?s apresentar o estado da arte da teoria dos dom?nios generalizada introduz-se uma generaliza??o original dos dom?nios alg?bricos nomeados como ?quase dom?nios alg?bricos?. Com uma ordem parcial adequada, constr?i-se um quase-dom?nio alg?brico para o conjunto de fun??es comput?veis totais. Por meio da topologia de Scott associada a esse quase-dom?nio alg?brico, obt?m-se uma condi??o necess?ria para as fun??es comput?veis regulares. Fica provado que esta ?ltima topologia n?o ? homeomorfa com o subespa?o previamente mencionado do espa?o de Baire apresentado. Como subproduto, introduz-se uma topologia de Scott para o conjunto de fun??es totais (n?o necessariamente comput?veis). Fica provado que esta ?ltima topologia n?o ? homeomorfa com o espa?o de Baire apresentado. Fica tamb?m provado que as topologias de Scott no conjunto de fun??es totais e no subconjunto de fun??es totais comput?veis t?m o conjunto de fun??es totais com suporte finito como conjunto denso comum. Analogamente, fica provado que a topologia no conjunto ?ndice do conjunto de fun??es totais comput?veis tem como conjunto denso os ?ndices correspondentes a uma enumera??o comput?vel sem repeti??o do conjunto de fun??es totais com suporte infinito. / Topologically the set of total computable functions has been studied only as a subspace of a Baire space. Where the topology of this Baire space is the induced topology of a Scott topology for the partial functions (not necessarily computable). In this thesis a novel topology on the index set of the set of total computable functions is built and proved that it is not homeomorphic to the aforementioned subspace of the presented Baire space. There is an important undecidable subset of the set of total computable functions called the set of regular computable functions that receives particular attention in this thesis. In order to make a topological study of this set a whole theoretical apparatus is constructed. After presenting the state of the art of generalised domain theory, a novel generalisation of algebraic domains coined as algebraic quasidomains is introduced. With a suited partial-order an algebraic quasi-domain is built for the set of total computable functions. Through the Scott topology associated with this algebraic quasi-domain a necessary condition for the regular computable functions is obtained. It is proved that this later topology is not homeomorphic to the previously mentioned subspace of the presented Baire space. As a byproduct a Scott topology for the set of total functions (not necessarily computable) is introduced. It is proved that this later topology is not homeomorphic to the presented Baire space. It is also proved that the Scott topologies in the set of total functions and in the subset of total computable functions have the set of total functions with finite support as a common dense set. Analogously it is proved that the topology in the index set of the set of total computable functions has as a dense set the indexes corresponding to a computable enumeration without repetition of the set of total functions with finite support.

The thesis is focused on analyzing and evaluation of importance and potential of fast-growing woody species for specifics of Czech economy and local conditions. Thesis will inquire into applicability of each fast-growing species for Czech natural conditions. Further I will investigate opportunities of subvention from public authorities. Next part of thesis will be focused on all activities and processes during cultivation of fast-growing species from acquiring land to processing of wooden mass. For each activity will quantify costs of labor and physical capital during cultivation of fast-growing woody species for different subjects in Czech economy, like household owning a soil or company with unused outside areas. Thesis will be comparing possible energetic savings of profits for a number of alternatives with different energy prices development in ongoing years. Practical output of this thesis should not be only the compilation of all these information into one text, but above all also a complex formula which everyone can use for the calculation of his opportunities for cultivating of fast-growing woody species.

Surface coal mining heavily disrupts vast areas of landscape. Previous studies conducted in these areas reveal that succession processes on unreclaimed sites support close to nature community. It's crucial to understand and be able to predict these processes in order to include spontaneous succession into restoration plans. The aim of my thesis is to clarify establishment and dispersion mechanisms of dominant pioneer woody species willow (Salix caprea), birch (Betula pendula) and aspen (Populus tremula). Study carried out on unreclaimed sites on a large colliery spoil heap near the town of Sokolov. I have studied establishment and growth of pioneer woody species on both graded and ungraded sites, representation of individual woody pioneer species was on sites in different distance from the edge of the spoil heap, birch's population age structure and reproduction potential of willow in accordance to age. All pioneer woody species establish and grow better on ungraded sites. The amount of willow decreases while the number of aspen individuals remains the same and the amount of birch increases with growing distance from the edge of the spoil heap. Birch's population age reveals establishment of new individuals in favourable climatic conditions. Willow is reproductively capable at the age of 10 years...

Made available in DSpace on 2014-12-17T14:56:17Z (GMT). No. of bitstreams: 1 EdsonAMRB_DISSERT.pdf: 7502344 bytes, checksum: 78d70443ae2fd9033fe78b23c5cbd811 (MD5) Previous issue date: 2013-07-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Complex network analysis is a powerful tool into research of complex systems like brain networks. This work aims to describe the topological changes in neural functional connectivity networks of neocortex and hippocampus during slow-wave sleep (SWS) in animals submited to a novel experience exposure. Slow-wave sleep is an important sleep stage where occurs reverberations of electrical activities patterns of wakeness, playing a fundamental role in memory consolidation. Although its importance there s a lack of studies that characterize the topological dynamical of functional connectivity networks during that sleep stage. There s no studies that describe the topological modifications that novel exposure leads to this networks. We have observed that several topological properties have been modified after novel exposure and this modification remains for a long time. Major part of this changes in topological properties by novel exposure are related to fault tolerance / A an?lise da topologia de redes ? uma poderosa ferramenta no estudo de sistemas complexos tal como as redes cerebrais. Este trabalho procura descrever as mudan?as na topologia de redes de conex?o funcional em neur?nios do c?rtex sensorial e do hipocampo durante o sono de ondas lentas (SWS) em animais expostos ? novidade. O sono de ondas lentas ? um importante estado do sono onde h? reverbera??o de padr?es de atividade el?trica ocorridos na vig?lia, tendo com isso papel fundamental na consolida??o de mem?ria. Apesar de sua import?ncia ainda n?o h? estudos que caracterizam a din?mica da topologia de redes de conex?o funcional durante este estado. Tampouco h? estudos que descrevem as modifica??es topol?gicas que a exposi??o ? novidade traz a essas redes. Observamos que v?rias propriedades topol?gicas s?o modificadas ap?s a exposi??o ? novidade e que tais modifica??es se mant?m por um longo per?odo de tempo. A maior parte das propriedades modificadas pela exposi??o ? novidade est? relacionada ? toler?ncia ? falha

Made available in DSpace on 2014-12-17T14:57:58Z (GMT). No. of bitstreams: 1 KarilanyDC_TESE.pdf: 5082673 bytes, checksum: 4427463c2d2c4ca61196bdca31ba604e (MD5) Previous issue date: 2014-06-10 / In recent years there has been a significant growth in technologies that modify implant surfaces, reducing healing time and allowing their successful use in areas with low bone density. One of the most widely used techniques is plasma nitration, applied with excellent results in titanium and its alloys, with greater frequency in the manufacture of hip, ankle and shoulder implants. However, its use in dental implants is very limited due to high process temperatures (between 700 C o and 800 C o ), resulting in distortions in these geometrically complex and highly precise components. The aim of the present study is to assess osseointegration and mechanical strength of grade II nitrided titanium samples, through configuration of hollow cathode discharge. Moreover, new formulations are proposed to determine the optimum structural topology of the dental implant under study, in order to perfect its shape, make it efficient, competitive and with high definition. In the nitriding process, the samples were treated at a temperature of 450 C o and pressure of 150 Pa , during 1 hour of treatment. This condition was selected because it obtains the best wettability results in previous studies, where different pressure, temperature and time conditions were systematized. The samples were characterized by X-ray diffraction, scanning electron microscope, roughness, microhardness and wettability. Biomechanical fatigue tests were then conducted. Finally, a formulation using the three dimensional structural topology optimization method was proposed, in conjunction with an hadaptive refinement process. The results showed that plasma nitriding, using the hollow cathode discharge technique, caused changes in the surface texture of test specimens, increases surface roughness, wettability and microhardness when compared to the untreated sample. In the biomechanical fatigue test, the treated implant showed no flaws, after five million cycles, at a maximum fatigue load of 84.46 N. The results of the topological optimization process showed well-defined optimized layouts of the dental implant, with a clear distribution of material and a defined edge / Nos ?ltimos anos tem-se observado um grande crescimento em tecnologias para modifica??o de superf?cies de implantes que reduzam o tempo de espera da cicatriza??o, assim como possibilite seu uso com sucesso em ?reas de baixa densidade ?ssea. Dentre as diferentes t?cnicas, a nitreta??o por plasma desponta como forte candidata, uma vez que a mesma j? est? sendo empregada com excelentes resultados no tit?nio e suas ligas, aplicados com maior frequ?ncia na confec??o de implantes de quadril, ombro e tornozelo. Entretanto, seu uso em implantes dent?rios ? bastante limitado devido ?s altas temperaturas do processo (entre 700 C o e 800 C o ) resultando em distor??es nessas pe?as que possuem geometria complexa e alto grau de precis?o. O objetivo deste trabalho ? avaliar a osseointegra??o e resist?ncia mec?nica de amostras de tit?nio grau II nitretadas, atrav?s da configura??o de descarga em c?todo oco. Al?m disto, propor formula??es para determina??o da topologia ?tima estrutural do implante dent?rio em estudo, com o intuito de aperfei?oar sua forma, que seja eficiente, competitiva e com alta defini??o. No processo de nitreta??o, as amostras foram tratadas em temperatura a de 450 oC e press?o de 150 Pa , durante 1 hora de tratamento. Esta condi??o foi escolhida por apresentar os melhores resultados de molhabilidade em trabalhos anteriores, onde sistematizou-se diferentes condi??es de press?o, temperatura e tempo. As amostras tratadas foram caracterizadas por Difra??o de Raios-X, Microscopia Eletr?nica de Varredura, Rugosidade, Microdureza e Molhabilidade. Posteriormente, foram realizados ensaios biomec?nicos de fadiga. Finalizando com uma proposta de formula??o atrav?s do m?todo de otimiza??o topol?gica tridimensional, combinado a um processo de refino h-adaptativo. Os resultados mostraram que a nitreta??o a plasma, utilizando a t?cnica de descarga em c?todo oco, produziu mudan?as na textura superficial dos corpos de prova, aumento da rugosidade superficial, da molhabilidade e da microdureza quando comparado a amostra sem tratamento. No ensaio biomec?nico de fadiga, o implante tratado n?o apresentou sinal de falha, ap?s cinco milh?es de ciclos, a uma carga m?xima de fadiga de 84, 46 N . Os resultados do processo de otimiza??o topol?gica apresentaram leiautes otimizados bem definidos do implante dent?rio, com uma n?tida distribui??o de material e defini??o do contorno.

3.2. Abstract Soil contamination by heavy metals represents rather serious environmental problem for both human health and an environment itself. One of the perspective technologies dealing with this threat that only recently has been intensely developed is phytoremediation by means of short rotation coppice plantations. As plants used in this technology (mostly poplars and willows) host two major groups of mycorrhizal fungi substantially influencing plant physiology it is important to study plant-mycobiontheavy metals interactions rather than just plant-heavy metals interactions. The present thesis aimed to contribute to the growing knowledge of the field by search for suitable mycobionts of poplar or willow tolerant to heavy metals, by evaluating an activity of the key antioxidative enzyme in selected mycobionts and by looking at physiological responses of plant hosts to their mycobionts in a soil polluted by heavy metals. The first experiment in vitro focused on screening of morphometric criteria of fungi growing on solid growth media amended with mixture of heavy metals. Based on the results, several tolerant ectomycorrhizal strains were chosen for the next inoculation of fast growing trees serving phytoextraction and phytostabilisation strategies. The second, re-synthetic experiment was conducted in...