The problem was to determine the effectiveness of using polyethylene glycol 1000 in the treatment of green wood for the purpose of forming projects made of wood veneer and of simple design for use in junior high or high school woodworking classes. The purpose of this study was to seek answers to the following questions. 1. Is polyethylene glycol 1000 an effective stabilizing agent for green wood veneer that can be used in school woodworking classes? 2. Can green wood veneer treated with polyethylene glycol 1000 be bent to form simple woodwork projects? 3. Can green wood veneer treated with polyethylene glycol 1000 be successfully used in junior high and high school woodworking classes? 4. What length of treatment time is best for green wood veneer that is to be used to form simple bent wood projects? 5. Is one-fourth inch thickness suitable for green wood veneer that is to be treated with polyethylene glycol 1000 and used to form simple bent wood projects?

This work examines extended, point, and surface defects in GaN by means of electric force microscopy, photoluminescence and deep-level transient spectroscopy. Modeling of the surface band bending, its origin, and the effects of fabrication processing steps are discussed in the first part of the dissertation. Experimental results indicate that spontaneous polarization does not play a predominant role in GaN band bending. An increase of surface band bending due to annealing and etching was observed, while passivation did not produce changes. However, passivation did reduce reverse-bias leakage current by one to two orders of magnitude in GaN Schottky diodes. The optical properties of GaN were found to be sensitive to fabrication processing steps, most likely due to changes in the total density of surface states.The second part of this dissertation concerns the reduction of extended defects and associated deep levels in layers of GaN grown on different templates. Templates employing a low temperature GaN nucleation layer, epitaxial lateral overgrowth, and SiNx nanonetwork are compared in terms of deep level concentrations in the resulting GaN films. The concentrations of two types of traps, A (Ec-ET ~ 0.54-0.58 eV) and B (Ec-ET ~ 0.20-0.24 eV), were the highest for the sample with a low temperature nucleation layer and lowest for a sample with a 6 min SiNx deposition time. We surmise that the defects responsible for the dominant trap A are located along dislocation lines and form clusters.In the last part we investigate the piezoelectric and ferroelectric properties of PZT in Pb(Zr, Ti)O3(PZT)/GaN structures, and the effects of interface states. Sol-gel derived thin PZT films on GaN and Pt/Ti/SiO2/Si surfaces were studied by piezoresponse force microscopy (PFM), where quantitative characterization of piezoelectric properties of PZT films was performed. Superior piezoelectric properties of PZT/GaN/sapphire structures as compared to PZT/ Pt/Ti/SiO2/Si structures were observed and explained by a different preferred orientation of PZT. Despite the possible existence of a strong depolarization field at the PZT/GaN interface, we confirm with PFM the presence of a remanent polarization in PZT/GaN/sapphire structures.

The active response of a series of polymeric materials was investigated. Both solvent activated and light activated thin films and wire systems show dynamic behaviors when exposed to different stimuli. Solvent mediated fluxional behavior of polymer thin films involved extensive, rapid curling both on infusion and evaporation of good solvents. These films can be either lab-fabricated ones or commercial ones, and the curling behavior can be as fast as seconds. Conditions including polymer materials, chosen solvents, and film geometry can affect the behavior. Methods that allowed for the creation and retention of distorted wire structures were also developed; the asymmetric sputtering of metal components on micron-sized wires permitted for the capture of curled wire components on solvent exposure. The asymmetric metal coated wires which were fabricated within a template of glass capillary arrays (GCA) membrane have shown instant (< 1 s) deformation when exposed to the proper solvents. Deformed shapes can be retained or the original linear shape recovered, depending on the metal film thicknesses. Photostimulation of wires was also investigated and showed a notable dynamic response but not as extensive as with the solvent induced behavior. Micron sized wires made with azobenzene-polyacrylate, exhibited a bending behavior when irradiated with 365 nm UV light and recovered under visible light. The bending behavior can be as slow as several minutes per degree while recovery was relatively faster. Additional efforts with polymers involved the formation of polymeric organic-inorganic hybrids where organic monomers, grafted to perovskite layers, were polymerized within the oxide’s interlayers. Reactions were carried out on protonated perovskite, hydrogen lanthanum niobate (HLaNb2O7). Alcoxyl groups were first grafted to the oxide and the monomer was substituted by exchange reaction with the alcoxyl groups.

Theoretical part PhD thesis describes bending of sheets especially with a small bend radius and the distribution of deformation and describes the parameters of bent sheet. As the test sheets were treated by cataphoretic coating is this method described together with pretreatment of sheet. The practical part is focused on the principle multi-jet plasma system and treatment of the steel surface and examines the bent surfaces of the steel sheets with different variants of applying the coating. Selected samples are bent on the multifunction graduated bending jig and subjected to the Erichsen test and deduced results using plasma system and without the use of plasma system. In the experimental part were examined samples treated by multi-jet plasma system and subsequently bent on the multifunction graduated bending jig. Compares the results of individual experiments in system steel – base coat – plasma – topcoat. And also compares mutual combinations of various kinds of modifying the surfaces of steel samples with different coatings. Selected samples were tested for tensile test and the results were processed from this test. For selected samples was calculated hardening exponent. Another experiment consists in applying a circle at equal samples and subsequently the samples were bent under a defined radius and were determined tensile and compressive deformation. Samples of sheets were then embedded in the resin and then examined under a microscope, where they were divided into several categories and was determined optimal composition multi-jet plasma system for selected samples and the specific coatings on sheet plate with a maximum adhesion of the coating to the steel base. Selected measured values were subjected statistical control.

O sucesso da terapia reabilitadora com implantes requer um equilíbrio entre fatores biológicos e mecânicos. Os fatores biológicos são inúmeros, já os mecânicos associam-se à instabilidade da interface implante-intermediário protético. Com base nestas informações, este estudo busca criar um aparelho com o qual será possível avaliar e comparar a resistência e a estabilidade da interface implante-intermediário protético em implantes de diferentes tipos de sistema de conexão e componentes protéticos, após a aplicação de carga simulada, que será realizada por meio de um ensaio dinâmico de fadiga rotacional, também conhecido como flexão rotativa. Para a criação deste aparelho, vários procedimentos com base em princípios de usinagem CNC (Controle Numérico Computadorizado), engenharia elétrica e física foram utilizados. Os futuros testes e resultados, utilizando-se esse aparelho para realizar o ensaio de fadiga, serão publicados em trabalhos futuros. Para o desenvolvimento dos modelos de corpos de prova a serem analisados na máquina de ensaio, foram utilizados implantes do tipo hexágono externo (Neodent) de 3,75mm de diâmetro x 11.5mm de comprimento. Ao término do desenvolvimento, obteve-se um aparelho confiável, resistente e extremamente versátil; podendo-se facilmente variar a carga exercida e a frequência de rotação, sendo assim possível executar inúmeras combinações de ensaios de fadiga. Esse estudo demonstrou a possibilidade e viabilidade de desenvolver um aparelho adequado para realizar um ensaio de fadiga, de pequena dimensão (portátil) e a um custo significativamente inferior do que comprar um aparelho próprio para tal fim. / The success of a rehabilitation therapy with implant fixtures requires a balance between biological and mechanical factors. The biological factors are innumerable, however the mechanics associate it whit instability of the implant-abutment interface. On the basis of these information, the aim of this study is to create a device which it will be possible to evaluate and to compare the resistance and the stability of the implant-abutment interface whith implants of different connection system and abutments, after the simulated load application, that will be carried through a dynamic assay of rotational fatigue load, also known as rotary bending. For the creation of this device, some procedures on the basis of principles of milling CNC (Computerized Numerical control), electric and physical engineering had been used. The future tests and results, using this device to carry through the fatigue assay, will be published in future works. For the development of the body test to be analyzed in the assay machine, implant fixtures of external hexagon type (Neodent) of 3,75mm of diameter x 11mm of length had been used. In the ending of the development, a trustworthy, resistant and extremely versatile device was gotten; being able itself easily to vary the exerted load and the frequency of rotation, being been thus possible to execute innumerable combinations of fatigue assays. This study demonstrated the possibility and viability of it developing an adequate device to carry through an assay of fatigue, of small dimension (portable) and the significantly inferior cost of what if to buy a proper device for such end.

A presente tese de doutoramento insere-se no debate sobre a temática da erosão e/ou neutralização da marca de gênero da Língua Hebraica Israelense nas relações morfossintáticas entre numerais cardinais e/ou pronomes com substantivos e configurações verbais do futuro em textos selecionados a partir do século XXI. O trabalho está fundado na percepção, derivada da literatura especializada sobre o tema, de que existe uma tendência da perda da marca de gênero nestas relações morfossintáticas estabelecidas, além de outras nuances como o apagamento do gênero feminino nas 2ª e 3ª pessoas plurais do sistema verbal no tempo futuro. Em termos de estratégias de pesquisa, a investigação fundamenta-se no estudo da formação e consolidação da identidade israelense e suas implicações equalizadoras no plano linguístico quanto ao uso da flexão de gênero tornando-os como unidade empírica. Nosso objetivo é examinar o funcionamento deste fenômeno linguístico, como isso é expresso na escrita e quais suas implicações na fala. A hipótese de trabalho para esta pesquisa é que o fenômeno de erosão e/ou neutralização da marca de gênero no Hebraico tem causado profundas transformações na estrutura da língua que se caracteriza na distinção clara de dois gêneros, seja nos nomes e numerais ou, ainda, no sistema verbal. Neste quadro, pretendo validar ou refutar conceitos tradicionais utilizados no estudo do Hebraico, tomando como base a medida da variação diglóssica. Por fim, desejamos, através dos dados obtidos nas obras selecionadas, apresentar nossas reflexões e apontar possíveis motivações para uma tendência erosão e/ou neutralização das configurações pesquisadas. / This doctoral thesis is part of the debate on the issue of erosion and / or neutralization of gender brand of Israeli Hebrew Language in morphosyntactic relationship between cardinal numbers and / or pronouns with noun and verb of the future settings on selected texts from the XXI century. The work is based on the perception, derived from the specialized literature on the subject, that there is a trend of the lost gender brand in these morphosyntactic relationships established, beyond other nuances like erasing female gender in 2nd and 3rd plural people of the verbal system in the future tense. In terms of research strategies, the investigation is based on the study of the formation and consolidation of Israeli Identity and their equalizing implications the linguistic plan in the use of gender bending making them as empirical unit. Our objetive is to examine the functioning of this linguistic phenomenon, as it is expressed in writing and what its implications in speech. The working hypothesis for this research is that the erosion phenomenon and / or neutralization of the gender brand in Hebrew has caused profound changes in the structure of language that characterized the clear distinction between two genres, whether the names and numerals, or more the verbal system. In this presentment, I intent to validate or refute traditional concepts used in the study of Hebrew, based on the measurement of diglossic variation. Finally, we wish through the data in the selected works, present our ideas and to point possible motivations for an erosion trend and / or neutralization of the surveyed settings.

O presente estudo visa comparar biomecanicamente, por meio do ensaio de flexão em quatro pontos, a resistência de segmentos de rádios de cães autoclavados e desvitalizados em nitrogênio líquido. Foram utilizados 20 cadáveres de cães de mais de dois anos de idade e massa corporal superior a 20 kg, portanto 40 rádios, que foram divididos em quatro grupos: grupo autoclave (GA), grupo controle autoclave (GCA), grupo nitrogênio (GN) e grupo controle nitrogênio (GCN). Os corpos de prova dos grupos GCA e GCN pertenciam ao lado contralateral dos grupos GA e GN, respectivamente. Os ossos foram autoclavados a 121&ordm;C, por 20 min a 2 atm. A desvitalização em nitrogênio foi realizada por meio da imersão em nitrogênio líquido, por 20 min, seguida de descongelamento à temperatura ambiente, sendo finalizada por imersão em solução de NaCL a 0,9%, por mais 15 min. A avaliação da resistência biomecânica foi realizada pelo ensaio de flexão em quatro pontos. Foi utilizado o programa de computador PMI para calcular o momento de inércia após o ensaio biomecânico destrutivo. Foram comparadas as variáveis força máxima, rigidez, altura máxima à secção transversa do corpo de prova, deslocamento do baricentro em relação ao eixo x, flecha, tensão-tração, tensão compressão e tensão máxima. Não foram encontradas diferenças estatisticamente significantes entre os grupos GN e GCN. Foram encontradas diferenças estatisticamente significantes entre os grupos GA e GCA somente na comparação da variável força máxima. A análise das variáveis tensão-tração, tensão-compressão e tensão máxima evidenciou diferenças estatisticamente significantes entre os grupos GA e GN, sendo os valores maiores para o grupo GA. Também foi realizada comparação entre os deltas (GN menos GCN e GA menos GCA) em que não foram observadas diferenças estatísticas. / The present study aim to, biomechanically compare through the four points bending test, the strenght of autoclaved and devitalized in liquid nitrogen radius segments. 20 corpses of dogs (>2 years of age and >20 kg of weight) were used. 40 radius were collected and divided into 4 groups, Autoclave Group (GA), Control Autoclave Group (GCA), Nitrogen Group (NG) and Control Nitrogen Group (GCN). Bone segments from groups GCA and GCN were contralateral to GA and NG. The segments were autoclaved at 121&ordm;C and 2 atm for 20 minutes. Nitrogen devitalization of the bone segments was obtained by 20 minutes immersion, followed by thawing at room temperature and 15 minutes immersion in 0,9% NaCL solution. The biomechanical strenght evaluation was performed in the four points bending test; afterwards, PMI computer program calculated the moment of inertia after the destructive biomechanical assay. Variables compared were maximum strength, stiffness, maximum high trough the transverse section of the bone segment, centers of mass dislocation in relation to x axe, arrow, stress-tension, stress-compression and maximum stress. No statistically significant differences between the GN and GCN groups were found. Statistically significant differences were found between groups GA and GCA only in the comparison of the maximum force variable. The analysis of variable stress-tension, stress-compression and maximum stress showed statistically significant differences between the GA and GN groups, with higher values for the GA group. Comparison of the deltas (GN least GCN and GA least GCA) that no statistical differences were observed was also performed.

A ABNT NBR 6118:2014 &#8211; Projeto de Estruturas de Concreto apresenta quatro métodos para dimensionamento de pilares, sendo necessário o uso de envoltórias de momentos quando houver flexão composta oblíqua. Devido à complexidade, não se considera de forma adequada a não linearidade física, a verificação de flexão composta oblíqua e as imperfeições geométricas locais. Este trabalho apresenta diretrizes para o dimensionamento de pilares retangulares de concreto com armadura simétrica, submetidos à flexão composta oblíqua, empregando-se as envoltórias mínimas e resistentes para verificação da armadura. São feitas análises de como as não linearidades influem no estado-limite último de instabilidade e como elas devem ser consideradas nos métodos de dimensionamento. São indicadas duas situações que podem ser críticas para o pré-dimensionamento. São elaborados roteiros para determinação das envoltórias solicitantes, para cada método de dimensionamento, e das envoltórias resistentes, por meio do cálculo direto ou com o uso de ábacos para flexão composta normal. Há, também, dois apêndices, um sobre a determinação dos diagramas momento fletor &#8211; força normal &#8211; curvatura para qualquer tipo de seção, e outro sobre obtenção dos diagramas de interação (Nu, Mu), construção de ábacos para flexão composta normal e definição da taxa mecânica de armadura &#969;, sem o uso de ábacos para concretos de classe até C50. Concluindo, este trabalho constitui uma bibliografia atualizada para o projeto de pilares seguros e economicamente viáveis, esclarecendo conceitos tais como momento fletor resistente, envoltórias solicitantes e resistentes e utilização das não linearidades nos métodos de dimensionamento. / The Brazilian Code ABNT NBR 6118:2014 &#8211; Design of concrete structures presents four methods for columns dimensioning, requiring the use of envelopment of moments when there is biaxial bending. Due to complexity, do not accurately consider physical nonlinearity, biaxial bending and local geometric imperfections. This work presents guidelines for the design of concrete rectangular columns with symmetrical reinforcement, subjected to biaxial bending, employing the minimum and resisting envelopment curves for the verification of the reinforcement. Analysis are made of how nonlinearities influence in the ultimate limit state of instability and how they should be considered in design methods. Two situations are indicated that can be critical for the pre-dimensioning of the reinforcement. Procedures are developed to determine the envelopment of acting moments, for each design method, as well as the envelopment of resisting moments by means of either direct method or use of abacuses for eccentrical compression. There is also two appendixes, one about the determination of the diagrams bending moment &#8211; normal force &#8211; curvature for any kind of section, and another one about getting interaction diagrams (Nu, Mu), construction of abacuses for eccentrical compression and definition of &#969;, the reinforcement mechanical rate, without the use of abacuses for C50 concrete class or below. In conclusion, this constitutes an updated bibliography for the safe and economically viable columns project, clarifying concepts such as resistant moment, envelopments of acting and resisting moments, and the use of nonlinearities in the design methods.

Os enrijecedores à flexão ou bending stiffeners contemplados neste trabalho são componentes estruturais auxiliares utilizados em linhas flexíveis em suas conexões com unidades flutuantes em sistemas de produção de petróleo offshore. A configuração destes acessórios deve conferir à instalação uma variação gradual da rigidez à flexão próximo ao ponto de fixação da linha flexível à unidade flutuante, diminuindo sua curvatura e suavizando o campo de tensões, evitando assim que a linha ultrapasse a curvatura máxima estabelecida em projeto. Na análise estrutural destes acessórios, diversas simplificações geométricas são consideradas e, em geral, os modelos propostos partem de uma geometria cônica simples. Na prática, entretanto, é comum a existência de unidades que envolvem até quatro diferentes seções. Este trabalho apresenta uma análise estrutural estática destes componentes complexos por meio de um modelo linear elástico, analiticamente formulado, que resulta em uma equação diferencial não-linear de segunda ordem com coeficientes variáveis. O problema matemático de valor de contorno é então solucionado numericamente com um código desenvolvido em Matlab®, usando uma função interna baseada no método de colocação em oposição ao método de tiros, freqüentemente usado em trabalhos anteriores. Finalmente, soluções previamente obtidas por outros autores com modelos analítico-numéricos e com elementos finitos são utilizadas para validar as soluções aqui obtidas, seguidas de uma análise paramétrica da geometria complexa de novos enrijecedores à flexão, além de breve discussão sobre análise dimensional e questões normativas relacionadas ao projeto destes acessórios. / The bending stiffeners discussed in this work are ancillary structural components installed on flexible lines at their connections with floating units in offshore oil production systems. The configuration of these accessories must provide the installation with a gradual variation of the bending stiffness near the lines attaching point, smoothing the curvature and the stress field of the compliant structure therein fixed, thus avoiding exceeding its designed structural bending limit. In the structural analysis of these accessories, several geometric simplifications are considered and, in general, the proposed models start from a simple conic geometry. In practice, however, bending stiffeners geometries are not so simple. Indeed, units consisting of four different sections are common. This work presents a parametric static structural analysis of these complex components by means of an analytically formulated linear elastic model, which results in a second order non-linear differential equation with variable coefficients. The ensuing mathematical boundary value problem is then solved numerically with a code developed in Matlab®, using an internal function based on the collocation method as opposed to the shooting method, frequently used in previous works. Finally, solutions obtained previously by other authors, with analytical-numerical and finite element models, are used to validate the solutions obtained herein, followed by a parametric analysis of the complex geometry of new bending stiffeners, besides brief related dimensional analysis and normative discussions.

Este trabalho enfoca a análise estrutural de um dos tipos de laje que vem ganhando espaço no mercado brasileiro, que é a laje formada por vigotas de concreto protendido. O objetivo principal do trabalho é contribuir na avaliação do comportamento desse tipo de laje com relação aos momentos fletores negativos no apoio, mediante análise teórica. Esta análise foi realizada a partir da relação momento x curvatura proposta pelo CEB-90 em conjunto com a técnica do carregamento incremental para a consideração da não-linearidade física do concreto. Esse método foi avaliado através da comparação com resultados experimentais de painéis alveolares encontrados na literatura, verificando que o modelo teórico representa satisfatoriamente o comportamento estrutural de lajes formadas por elementos pré-moldados protendidos. A partir disto, fez-se análises em situações representativas de projeto de lajes formadas por vigotas protendidas, chegando-se as seguintes conclusões: a) a utilização da continuidade favorece fortemente a redução dos deslocamentos; b) os deslocamentos praticamente independem da taxa de armadura de continuidade; c) a evolução do momento fletor negativo no apoio e momento fletor positivo máximo no vão apresentou um comportamento padrão para os casos analisados; d) esse comportamento foi independente da taxa de armadura de continuidade e e) a taxa de armadura de continuidade afetou praticamente o valor da carga última. / This work aims the structural analysis in a type of slabs that is increasing its utilization in Brazil. These slabs are made by precast prestressed joists. The main objective of this work is the evaluation of the behavior of this type of slabs by theoretical analysis of the bending moments on the supports of continuous slabs. In the theoretical analysis was carried out the consideration of the non-linear of the concrete behavior through the moment x curvature relationship of Model Code CEB-90 add incremental load technique. This methodology was appraised with experimental results of panels of hollow core slabs and this methodology was able to represent satisfactorily the behavior of slabs made by precast prestressed elements. Analysis of representative cases of slabs with precast prestressed joists was carried out and the main conclusions were: a) the use of continuity aids highly to decrease the displacements; b) displacements were practically independent of reinforcement ratio on the support; c) the development profiles of the bending moments had a standard behavior to the analysed cases; d) this behavior was independent of reinforcement ratio on the support and e) the reinforcement ratio on the support affected practically the ultimate load value.