A utilização de ondas guiadas em técnicas de monitoramento de integridade estrutural tem se mostrado uma alternativa interessante para economia de tempo e de custos de operação. Técnicas com ondas guiadas apresentam a característica de monitorar trechos extensos de uma estrutura a partir de um único ponto de acesso, permitindo a inspeção de partes remotas e de difícil acesso. Entre os modos fundamentais de propagação de ondas guiadas em chapas, o modo SH0 possui a vantagem de não ser dispersivo, além de sofrer menores atenuações ao se propagar em superfícies em contato com fluidos. Neste trabalho é proposto um modelo de transdutor do modo SH0 de forma omnidirecional em uma chapa de aço utilizando um arranjo com cerâmicas piezoelétricas, que permita inspecionar determinada área de um componente através de um único modo de propagação. Para caracterizar e compreender o comportamento da resposta obtida foram realizadas simulações numéricas parametrizando características do modelo proposto, como o número de elementos piezoelétricos e dimensões geométricas dos componentes do transdutor. Para validação dos resultados do modelo numérico foram construídos modelos experimentais do transdutor, os quais foram instalados sobre uma chapa de aço de 2mm de espessura para verificação dos modos de propagação emitidos. Avaliando a relação entre intensidades de cada modo emitido e a qualidade da emissão de SH0 foi possível identificar as frequências que apresentaram resposta com a característica desejada. Também foi verificado o comportamento dos transdutores construídos ao serem excitados por ondas propagando na chapa, avaliando a sua utilização também como receptores. / The use of guided waves in structural health monitoring techniques has already proved to be an interesting alternative to reduce inspection time and overall operational costs. Guided waves techniques enable monitoring large structures from one single access point, allowing the inspection of distant and hard access parts. Among the fundamental propagation modes of guided waves in plates, the SH0 mode has the advantage of being non dispersive, as well as being subject to less attenuation when propagating through surfaces in contact with fluids. In this work, it is proposed one omnidirectional SH0 mode transducer in a steel plate using a piezoelectric ceramic array, which allows inspecting a component area through a single propagation mode. Numeric simulations parameterizating features of the transducer, such as the number of piezoelectric elements and the geometric dimensions of the transducer’s components, were developed to characterize and investigate the effect on the output response. To validate the numeric simulation results, experimental models of the transducer were built, which were installed on a 2mm thick steel plate to verify the generated propagation modes. The analysis of the relation between the intensity of each mode generated in the plate and the emission quality of the SH0 mode allowed the identification of frequencies that presented the most desirable response characteristics. The behavior of the built transducers was also studied when they were excited by waves propagating through the plate, evaluating the use of the transducers as signal receptors.

In recent decades techniques related to the measurement of elastic waves have advanced significantly. It is now possible with relatively inexpensive equipment to record amplitudes and frequency bands that were unthinkable two decades ago. This has led to the development of theoretical topics which application was questionable until not long ago, to profit from new technological potential in obtaining more and better experimental information. In this context the study of the propagation of guided waves in solids is presented as a knowledge that allows to detect damage with efficiency and economy in a number of structures in which at least one dimension is much larger than the other two. This is the case for rails, tubulations and pressure vessels among others. In this work, guided waves propagation characteristics are studied, first in a prismatic bar and then within the geometry of a rail. In both cases, dispersion curves were computed according two different work methodologies, first using an axisymmetric model and then corroborated with a model of periodic conditions. Finally propagation of a Tone-Burst waves were simulated on the analyzed geometries, leading to the discussion of how the waves scatter along its propagation. The results obtained were the dispersion curves of both sections. / En las últimas décadas técnicas relacionadas con la medición de ondas elásticas han avanzado sensiblemente. Actualmente, con equipamientos relativamente económicos es posible registrar amplitudes y franjas de frecuencia que eran impensables dos décadas atrás. Este hecho ha motivado que tópicos teóricos que hasta hace un tiempo tenían una aplicación cuestionable tengan que ser desarrollados para poder aprovechar las nuevas potencialidades tecnológicas en la obtención de mayor y mejor información experimental. En este contexto, el estudio de la propagación de ondas guiadas en sólidos se presenta como un conocimiento que posibilita detectar daño con eficiencia y economía en una serie de estructuras en las cuales por lo menos una dimensión es mucho mayor que las otras dos. Es el caso de estructuras tubulares, rieles o recipientes sometidos a presión entre otras. En el presente trabajo se estudian las características de propagación de ondas guiadas primeramente una barra rectangular y posteriormente en la geometría de un riel. En ambos casos, fueron calculadas las curvas de dispersión obtenidas con por dos metodologías de trabajo por elementos finitos, la primer metodología fue emplear un cálculo aplicando un modelo axisimétrico, y luego corroborado con un modelo de condiciones periódicas y posteriormente fue simulada la propagación de una onda tipo Toneburst sobre las geometrías analizadas discutiendo cómo dicha onda se dispersa durante su propagación. Los resultados obtenidos fueron las curvas de dispersión de ambas secciones.

Sistemas de ensaios não destrutivos por ondas guiadas despertam cada vez mais a atenção tanto da indústria, como da academia. Isso deve-se, principalmente, às possibilidades que as ondas guiadas permitem, como maior área de triagem que o ultrassom convencional. Porém a técnica tem suas limitações, já que esta apenas gera uma estimativa da localização de um defeito e não a sua dimensão. Nessa limitação, algoritmos tomográficos apresentam uma possibilidade de avanço da técnica, pois permitem determinar não só a localização de corrosões e defeitos, mas também seu dimensionamento. Este trabalho apresenta tomografia de difração como uma alternativa para avaliação de integridade estrutural. Primeiramente, utilizou-se análise por métodos numéricos para mostrar a validade dos algoritmos e posteriormente foi realizado um experimento em uma chapa real com o objetivo de reconstruir a imagem do defeito. / Guided waves nondestructive testing systems are increasingly attracting industrial and academic attention. The mainly reason for this attention is the possibility of screening a large area than conventional ultrasound technique. However, Guided Waves Testing has limitations, since it gives only an estimation of the location of a defect, but not the dimensions. Tomographic algorithms come up with an improvement of the technique, because it allows discovery not only the location of corrosions and defects, but the dimensions too. This work brings Diffraction Tomography as an alternative to structural health monitoring. First, a numerical analysis was implemented to demonstrate the validity of the algorithms, after that an experiment in a real plate was made with the objective to recover the defect image.

Orientador: Leila Aparecida Chiavacci / Coorientador: Bruno Leonardo Caetano / Banca: Ana Maria Minarelli Gaspar / Banca: Giancarlo Esposito de Souza Brito / Resumo: Dentre as membranas utilizadas para regeneração óssea guiada as membranas reabsorvíveis se destacam por não necessitarem do segundo ato cirúrgico, fato esse que pode ocasionar lesões no tecido estabelecido além do incomodo que o segundo ato cirúrgico em si proporciona ao paciente. Entretanto, não existe no mercado uma membrana considerada adequada. O objetivo deste trabalho foi desenvolver uma membrana a partir de materiais híbridos ureasil-poliéter para regeneração óssea guiada, capaz de isolar o enxerto ósseo e simultaneamente liberar de forma controlada fármacos ou proteínas, resultando assim em uma membrana capaz de melhorar a resposta fisiológica do tecido ósseo diminuindo o tempo de neoformação óssea. Os materiais utilizados foram sintetizados a partir do método sol-gel utilizando os polímeros Poli Oxido de Etileno (POE) e Poli Oxido de Propileno (POP) de diferentes massas moleculares (400, 1900, 2000 g mol-1). O fármaco utilizado como modelo foi o Acetato de Dexametasona. Os resultados de intumescimento na presença de saliva artificial revelaram que com o aumento na proporção de ureasil-POP2000 e ureasil-POE1900 na mistura ocorre um aumento no ganho de massa, contudo esse aumento é mais expressivo para as misturas com ureasil-POE1900. A evolução das curvas de SAXS durante os experimentos de liberação com saliva artificial revela que a mistura formada por ureasil-POP400/POE1900 leva ao deslocamento do pico de correlação para baixos valores de q e ao aumento na intensidade do pico, por outro lado devido à razão hidrofóbica na mistura ureasil-POP400/POP2000 esse deslocamento para baixos valores de q é invariável. O teste de liberação revelou que é possível controlar a velocidade de liberação do fármaco a partir da variação das misturas ureasil-POP400/POP2000 e ureasil-POP400/POE1900. Resultados da análise... / Abstract: Among the membranes used for guided bone regeneration the resorbable membranes stand out for do not need the second surgery, a fact that can cause tissue damage beyond uncomfortable that the second surgery itself provides the patient.However, there is no on the market a membrane considered appropriate. The objective of this study was to develop a membrane from hybrid materials ureasil polyether for guided bone regeneration, able to isolate the bone graft and simultaneously drug release controlled or protein, resulting in a membrane capable of improving the physiological response of the tissue bone decreasing the bone formation. The materials used were synthesized from solgel method using polymers poly ethylene oxide (POE) and poly propylene oxide (POP) of different molecular weights (400, 1900, 2000 g mol-1).The drug used as model was dexamethasone acetate. The results of swelling in the presence of artificial saliva showed that with the increase in the proportion of ureasilPOP2000 and ureasil POE1900 in the mixture occurred an increasing mass, but this increase is more significant for mixture with the ureasil-POE1900.The evolution of SAXS curves during the release experiment with artificial saliva reveals that the mixture formed by ureasil-POP400/POE1900 leads to displacement of the correlation peak for low values of q and the increase in the intensity of the peak but the reason hydrophobic in the mix ureasilPOP400/POP2000 this displacement for low values of q is invariable. The release test showed that it is possible to control the release rate of the drug from the variation of the mixtures and ureasil-POP400/POP2000 ureasilPOP400/POE1900. Results of the microtomography showed that bone defects containing the ureasil-polyether membranes tested showed bone growth statistically similar to bone defects containing commercial collagen membrane (Bio-Gide, Geistlich Pharma). / Mestre

Este trabalho aborda o controle de um veículo aéreo não tripulado (VANT) com carga pendular acoplada. Veículos autônomos apresentam desafios de controle dadas suas características como não linearidades, acoplamento de movimentos, dinâmicas desconhecidas, distúrbios ambientais e ser um sistema do tipo subatuado. O veículo aqui estudado apresenta seis graus de liberdade relativos ao movimento de corpo livre do robô e dois graus de liberdade adicionados pela carga pendular acoplada. Seu modelo matemático é deduzido através das equações de Lagrange, linearizado em torno do ponto de operação e validado através de simulações. O projeto de controle é baseado nos controladores lineares dos tipos PID, LQR e H? para sistemas multivariáveis. Uma vez obtidos os controladores, são apresentadas as simulações para três cenários distintos considerando estabilização a partir de condições iniciais e perturbações e incertezas. Os controladores resultantes das sínteses são simulados com a planta linear e não linear e verificados conforme seu desempenho. / The present work is focused on the stabilization control of Unmanned Aerial Vehicles (UAV) connected with a slung load. UAV Control is a challenging subject due its characteristics such as non-linearities, coupling dynamics, unknown dynam-ics, environmental disturbances which they are subjected and their underactuated nature. The vehicle presents six degrees of freedom relative to its free body configu-ration and two additional degrees of freedom for it slung load coupling. The mathe-matical model is derived for this configuration through the Lagrange approach, further linearized around its operation point and validated through simulations. The Control Design is based on three different linear controllers, PID, LQR and H? for multivariate systems. Once designed, they are simulated with the linear-ized plant and the non-linearized plant considering three different scenarios for stabi-lization. Finally, the controllers are tested and simulated on a virtual model and the results are presented and discussed.

Structures made of plate-like components are common in a variety of industries where the impacts of structural failures are severe. In many cases these structures are surrounded and only partially accessible, such as storage tanks and bridges, making them difficult to inspect frequently. The application of ultrasonic Guided Waves (GWs) in the evaluation and monitoring of relatively large plate-like structures is evermore a feasible option with the continuous development of transducer arrays. The use of transducer arrays is however complex due to directional control and the existence of many GW modes. Aimed at the evaluation of plate-like structures, in this research two piezoelectric transducer arrays respectively capable of omnidirectional and unidirectional control of the fundamental GW shear mode in plates (SH0) with above 20 dB mode purity are successfully designed, produced and validated. Omnidirectionality facilitates full structural evaluation coverage and can lead to defect mapping of large volumes with relatively few transducers. A unidirectional beam with relatively high mode purity facilitates evaluation of specific structural locations. Preference to the SH0 mode was given because of its non-dispersive and in-plane propagation properties making it more suitable than other GW modes to propagation in structures surrounded by fluid material. To enable the array development, a number of monolithic piezoelectric thickness-shear transducers of varied area were characterised with respect to GW mode directionality, amplitude and SH0 mode purity. The characterisation of each thickness-shear transducer allows for optimised superposition manipulation for specific applications. A single characterised shear transducer was selected for use in the development of omnidirectional and unidirectional SH0 mode transducer arrays. To aid development a linear superposition analysis model was produced and used to predict for a circular array design the optimum parameters for omnidirectional SH0 mode transmission with significant mode purity. A range of parameter combinations were evaluated and their predicted influence on array performance was characterised. The same method was employed to optimise a dual row linear array design for the unidirectional transducer array. All results were validated by FE models and later with empirical data. Both developed transducer arrays were characterised with respect to GW mode directionality, magnitude and SH0 mode purity. Both their detection sensitivity to pertinent defects and structures was validated, demonstrating relevance to Non Destructive Evaluation (NDE) and Structural Health Monitoring (SHM) applications.

Bone quality influences bone strength with important consequences for osteoporosis, fracture risk and dental implant success. Whilst imaging that is capable of capturing bone structure in 3D is becoming more common, quantitative clinical measures of bone quality rely on bone quantity, not structure. If bone quality could be more accurately measured, and the influence of bone architecture better understood, strength may be better predicted. This thesis presents methods for making structural comparisons between successive micro-CT images of loaded bone and explores the limitations of these. I present a novel method to detect where damage occurs in loaded rat vertebrae based on multiscale rigid registration and difference measures. Together these methods represent a quantitative approach to image guided failure analysis. Time-lapsed micro-CT images of 14 successively loaded rat vertebrae were acquired and damaged regions found using these. Using a random forest classifier I tested whether the damaged regions could be predicted by several commonly used structural measures (bone area and volume), three-dimensional texture measures (co-occurrence matrices and fractal dimension) and a more novel type of architectural measure (based on the structure tensor). A combination of parameters was able to predict damage regions with specificities in the range 70-90% and sensitivities of 60-70%.Using ovariectomised rats as a model of osteoporosis I have performed a pilot experiment to investigate how changes in bone quality might effect our results. The wider applicability of my methods are demonstrated by applying them to dental cone beam images of healthy and osteoporotic patients.

This study was an investigation of the effects of guided listening upon instrumental music performances of junior college students. The study also sought to discover possible significant relationships between perception and performance variables. It was concluded that the guided listening program was ineffective in improving music performances of junior college students. It was recommended that (a) this study be replicated utilizing string, voice, and piano students, (b) an experimental study be made to investigate the effects of music theory instruction upon music performance, (c) an experimental study be made to investigate the effects of music history instruction upon music performance, and (d) an investigation be made of the Abeles performance constructs interpretation, tone, rhythm-continuity, intonation, tempo, and articulation, in an effort to ascertain ways in which expression of these constructs may be improved.

Orientador: Rosemary Adriana Chiérici Marcantonio / Banca: Joni Augusto Cirelli / Banca: Elizabeth Pimentel Rosetti / Banca: Washington Rodrigues Camargo / Banca: Giuseppe Alexandre Romito / Resumo: O propósito deste estudo foi avaliar histológica e histometricamente o resultado da utilização das matrizes de colágeno de Pericárdio Bovino (MPB) e Dérmica Acelular (MAD) no tratamento de deiscências ósseas criadas cirurgicamente em cães. Foram criados defeitos periodontais do tipo deiscência óssea na superfície vestibular dos 2os, 3os e 4os pré-molares inferiores de seis cães. Estes dentes foram divididos em 3 grupos: grupo I: MAD; grupo II: controle e grupo III: MPB, ambos com reposição coronária do retalho. Após 70 dias os animais foram sacrificados, os dentes retirados em bloco e processados histologicamente. Realizou-se análise histológica descritiva e histométrica, medindo-se a extensão do tecido epitelial, neoformação óssea e cementária e nível gengival para os grupos I, II e III. Os resultados demonstraram valores estatisticamente iguais para as medianas (em mm) dos valores de epitélio: 1,49, 1,91 e 1,82; cemento: 3,18, 3,09 e 3,31 respectivamente para os grupos I, II e III. Foi encontrada diferença estatisticamente significante em relação à neoformação óssea, com medianas (em mm) de 1,23, 1,82 e 1,62, respectivamente para os grupos I, II e III. Foi observado escasso infiltrado inflamatório. Com isso, pudemos concluir que as matrizes de MPB e MAD são materiais que permitem a reparação dos tecidos periodontais. / Abstract: The goal of this investigation was to compare, histologically and histometrically, the healing process of dehiscence-type defects treated by acellular dermal matrix (AD) and bovine pericardium matrix (PB). Six mongrel dogs were used. Buccal osseous deiscences were surgically created on mesial roots of the mandibular second, third and fourth premolars. The defects were randomly assigned to one of the treatments: AD, control and PB. After 70 days of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included: gingival level, epithelial length, new cementum and new bone. No statistically significant differences were found between PB, AD and control groups for epithelial length and new cementum parameters (p<0,05). Statistically significant differences were found between PB, AD and control groups for new bone (minor for AD). The presence of a slight inflammation was observed. Withim the limits of this study, it can be concluded that PB and AD showed good biocompatibility, but did not bring a complete periodontal tissue regeneration. / Doutor

Ce travail a pour objectif de mettre en évidence les effets de la simulation mentale guidée sur l’apprentissage, sur la performance et sur l’image du mouvement en danse. Dans la revue de littérature, nous présentons les principales théories de l’apprentissage cognitif et socio-cognitif, ainsi que les mises en œuvre des méthodes d’apprentissage issues de ces deux champs théoriques. Puis, à partir des spécificités de la danse « didactisée », des transformations visées en milieu scolaire et universitaire, et de la place des images mentales en danse, nous envisageons la simulation mentale guidée par des consignes rythmiques, motrices et métaphoriques. Nous présentons ensuite une étude préliminaire visant la construction d'outils d'évaluation de la performance en danse, ainsi que deux études expérimentales menées auprès de sujets adultes novices portant sur l'apprentissage lors de tâches de reproduction de forme et d'improvisation-composition. Les résultats dans ce qu'ils ont d'essentiel montrent (1) que la simulation mentale est une méthode d'apprentissage plus efficace que l'observation à partir du moment où elle est guidée, (2) que les consignes rythmiques sont fondamentales dans l'apprentissage en danse parce qu'elles permettent d'organiser et de structurer le mouvement, (3) que les consignes métaphoriques apparaissent particulièrement adaptées à la dimension expressive et artistique de la danse. Dans leur ensemble, ces résultats soulignent l'importance de guider la simulation mentale à l'aide de consignes pour s'assurer de son efficacité dans l'apprentissage. / This study aims to highlight the effects of mental simulation of guided learning, performance and image of the movement in dance. In the literature review, we present the main theories of cognitive and socio-cognitive, and implementations of learning methods from these two theoretical fields. Then, from the specifics of the dance "didactical" transformations referred by schools and universities, and the place of mental images in dance, we consider the mental simulation guided by rhythmic and metaphorical instructions. Afterwards, we present a preliminary study for the tool construction for assessing performance in dance, and two experimental studies conducted with novice adult subjects on learning tasks during reproduction of form and improvisation-composition. The results in their essence show (1) that mental simulation is a more effective method of learning than observation, from the moment it is guided 2) that the rhythmic instructions are fundamental in dance learning because they help to organize and structure the movement, (3) that the metaphorical instructions seem particularly suited to the expressive and artistic dimensions of dancing. Taken together, these findings emphasize the importance of guided mental simulation with instructions to ensure its effectiveness in learning.