Este trabalho procurou analisar os fatores influentes nos processos erosivos na bacia do córrego Tuncum, município de São Pedro-SP, através de características observadas, tanto no campo como em laboratório (ensaios geotécnicos de caracterização de solos e ensaio de erodibilidade), onde se constatou que as áreas que apresentam alta susceptibilidade aos processos erosivos estão associados principalmente ao material geológico constituinte da bacia. Para o estudo da evolução das feições erosivas foram utilizadas fotografias aéreas de três diferentes datas (1972, 1995 e 2000), e com auxílio de técnicas de geoprocessamento realizou-se um tratamento qualificado das informações adquiridas. A análise das informações obtidas permitiu o estabelecimento da susceptibilidade à erosão que associada às informações de uso e ocupação conduziu a definição de prognósticos acerca da evolução dos processos erosivos na área. Os documentos cartográficos elaborados foram o mapa de documentação, mapa de Landforms, carta de declividade, mapa de materiais inconsolidados, carta de susceptibilidade à erosão e carta de prognósticos ao desenvolvimento de erosões lineares. / This work aims to analyze the main factors related to the erosion processes in the Tuncum creek watershed, city of São Pedro-SP, based on the observed geological-geotechnical characteristics in the field and laboratory (soil geotechnical characterization and erodibility tests). It was verified that high susceptibility area to the erosion processes are mainly associated to geological materials of the watershed. For the study of the evolution erosion features were used aerial photographs of three different dates (1972, 1995 and 2000), and with aid of geoprocessing techniques realized a qualified treatment to the acquired informations. The analysis of the obtained informations allowed the establishment of the erosion susceptibility that associated to the information of use and occupation lead the definition of prognostics concerning the evolution of the erosive processes in the area. The cartographic documents elaborated were documentation, landforms and unconsolidated materials maps, declivity, susceptibility to erosion and prognostic to the development of linear erosions charts.

Made available in DSpace on 2016-08-17T14:53:29Z (GMT). No. of bitstreams: 1 Joao Rodrigo Ferreira.pdf: 1547613 bytes, checksum: a9c7e73154b7e9a72733f9f2e20a55fe (MD5) Previous issue date: 2007-12-07 / The lung cancer is a disorder with significant prevalence in several countries worldwide. The hard treatment and the fast progress of the disease increase the mortality rates. The main factor contributing to a successful treatment is an early diagnosis. However possible omissions in the scan analysis can lead to late diagnosis, compromising all the treatment. In order to present a computational tool aimed at nodules detection, that can be used as a second opinion to the specialist, this master thesis proposes a methodology for nodules detection that is totally automatic, robust and consistent. The methodology is based on successive refinements for the segmentation of computed tomography images using morphologic techniques to obtain nodule candidates. The false positive reduction is achieved by SVM based on geometric and texture features. The tests, performed with real scans, indicate the feasibility of the proposed method. In automatic detection performed on 33 cases the methodology reached 95.21% of correctness with 0.42 false positives and 0.15 false negative per scan. / O câncer de pulmão é uma enfermidade com prevalência significativa em diversos países no mundo todo. O difícil tratamento e a progressão rápida da doença fazem com que os índices de mortalidade das pessoas acometidas por este mal sejam muito altos. O principal fator contribuinte para um tratamento de sucesso, entretanto, é o diagnóstico precoce. Contudo possíveis omissões na análise dos exames podem levar a um diagnóstico tardio, comprometendo todo o tratamento. Com o intuito de oferecer uma alternativa computacional de auxílio à detecção de nódulos, servindo como uma segunda opinião para o médico, este trabalho propõe uma metodologia totalmente automática, robusta e consistente. A metodologia é fundamentada em refinamentos sucessivos da segmentação sobre imagens de tomografia computadorizada utilizando técnicas morfológicas para a obtenção de candidatos a nódulo. A redução de falsos positivos é efetivada pelo SVM com base em características geométricas e de textura. Os testes realizados com exames reais indicam a viabilidade da solução proposta. Na detecção automática realizada sobre 33 casos a metodologia atingiu 95,21% de acerto com uma média de 0,42 falsos positivos e 0,15 falsos negativos por exame.

Cette thèse intervient dans le cadre du projet ANR ARMS. L'objectif est de concevoir un système robotisé multi-bras pour la découpe anatomique de muscles. Ce travail vise à développer les modèles mécaniques nécessaires à la mise en place de la stratégie de commande. Il expose le cycle de développement d'un modèle mécanique faisant intervenir la construction de modèles géométriques à partir d'images IRM, l'identification expérimentale des paramètres rhéologiques des matériaux modélisés en passant par les étapes de maillage, de paramétrage, d'implémentation et de validation de tels modèles. Il présente une nouvelle méthode de modélisation dynamique de structures intitulée modèle masse-ressort non-linéaire isotrope transverse, une méthode qui témoigne d'un comportement mécanique alliant réalisme et interactivité. Il intervient aussi dans l'identification dynamique des trajectoires de coupe robotisée en proposant de nouvelles approches de modélisation de la découpe de corps mous et en développant un nouvel algorithme basé sur le calcul de courbures. Cette thèse aborde, aussi, le problème de variabilité des muscles bovins et propose une méthode de recalage dimensionnel du modèle géométrique générique par le biais de transformations géométriques définies par optimisation multicritère d'une fonction objectif. Enfin, en vue de synchroniser le flux d'informations entre les différents modules de commande de la cellule robotisée, une combinaison de la méthode des éléments finis avec la technique de condensation statique de Guyan a permis de développer un modèle mécanique quasi-statique réduit permettant de prédire rapidement l'évolution de la trajectoire de coupe robotisée. / This PhD thesis is done within the framework of the ANR ARMS project. The global objective is to study the robotization of deboning and muscle separation in meat cutting and transformation processes applied to beef rounds. This work aims to develop the necessary mechanical models feeding the process control strategy. It outlines the development cycle of a mechanical model involving the construction of geometrical models using MRI techniques, the experimental identification of rheological parameters of materials while going through the steps of meshing, parameterization, implementation and validation of such models. It presents and tests a new way to fix the parameters of the mass-spring model whilst taking into account material anisotropy. The new approach is entitled « non-linear transversally isotropic mass-sping model » and sets the model in non-linear mechanical behavior mode which therefore increases the realism of the simulations performed. It is also involved in the dynamical estimation of the cutting guideline by proposing new approaches for soft materials cutting and by developing a new algorithm based on vision perception and curvature estimation of 3D surfacic meshes. This work addresses also the problem of muscles variability and provides a readjustement method of the generic geometrical model based on a multicriteria optimization of an objective function. Finally, in order to synchronize the information flow between the control modules of the robotic cell, a combination of the finite element method with Guyan static condensation technique allowed developing a reduced quasi-static mechanical model rapidly predicting the evolution of the cutting trajectory.

Ce manuscrit est dédié à la détection et la caractérisation de points d'intérêt dans les maillages. Nous montrons tout d'abord les limitations de la mesure de courbure sur des contours francs, mesure habituellement utilisée dans le domaine de l'analyse de maillages. Nous présentons ensuite une généralisation de l'opérateur SUSAN pour les maillages, nommé SUSAN-3D. La mesure de saillance proposée quantifie les variations locales de la surface et classe directement les points analysés en cinq catégories : saillant, crête, plat, vallée et creux. Les maillages considérés sont à variété uniforme avec ou sans bords et peuvent être réguliers ou irréguliers, denses ou non et bruités ou non. Nous étudions ensuite les performances de SUSAN-3D en les comparant à celles de deux opérateurs de courbure : l'opérateur de Meyer et l'opérateur de Stokely. Deux méthodes de comparaison des mesures de saillance et courbure sont proposées et utilisées sur deux types d’objets : des sphères et des cubes. Les sphères permettent l'étude de la précision sur des surfaces différentiables et les cubes sur deux types de contours non-différentiables : les arêtes et les coins. Nous montrons au travers de ces études les avantages de notre méthode qui sont une forte répétabilité de la mesure, une faible sensibilité au bruit et la capacité d'analyser les surfaces peu denses. Enfin, nous présentons une extension multi-échelle et une automatisation de la détermination des échelles d'analyse qui font de SUSAN-3D un opérateur générique et autonome d’analyse et de caractérisation pour les maillages / This manuscript is dedicated to the detection and caracterization of interest points for 3D meshes. First of all, we show the limitations of the curvature measure on sharp edges, the measure usually used for the analysis of meshes. Then, we present a generalization of the SUSAN operator for meshes, named SUSAN-3D. The saliency measure proposed quantify the local variation of the surface and classify directly the analysed vertices in five classes: salient, crest, flat, valley and cavity. The meshes under consideration are manifolds and can be closed or non-closed, regulars or irregulars, dense or not and noised or not. The accuracy of the SUSAN-3D operator is compared to two curvature operators: the Meyer's operator and the Stokely's operator. Two comparison methods of saliency and curvature measures are described and used on two types of objects: spheres and cubes. The spheres allow the study of the accuracy for differentiable surfaces and the cubes for two types of sharp edges: crests and corners. Through these studies, we show the benefits of our method that are a strong repeatability of the measure, high robustness to noise and capacity to analyse non dense meshes. Finally, we present a multi-scale scheme and automation of the determination of the analysis scales that allow SUSAN-3D to be a general and autonomous operator for the analysis and caracterization of meshes

Afin de diminuer les consommations énergétiques, plusieurs pays Européens, y compris la France, ont mis au point de nouvelles normes permettant d'optimiser les performances énergétiques de l'enveloppe du bâtiment. Ceci peut entraîner l'augmentation de l'humidité relative, ce qui peut nuire à la santé des occupants et dégrader la structure du bâtiment. Utiliser des éco-matériaux tel que le béton de chanvre est une solution prometteuse permettant d'assurer le confort à l'intérieur du bâtiment, en régulant l'humidité relative. L'objectif principal de cette thèse est d'élaborer, optimiser et caractériser un agromatériau à base de la chènevottes défibrée avec un liant d'amidon de blé. La formulation du chanvre-amidon est étudiée en variant le rapport massique amidon/chanvre et son impact sur les propriétés mécaniques. Le coefficient d'absorption acoustique est mesuré pour la composition optimale. Pour améliorer les propriétés d'adhésion à l'interface chanvre/amidon, un traitement de surface à base d'hydroxyde de sodium NaOH suivi par un agent de couplage (3-glycidyloxypropyl) triméthoxysilane ont été effectués. L‘influence du traitement de surface sur les fibres de chanvre a été analysée au microscope électronique à balayage (MEB), par la calorimétrie différentielle à balayage (DSC), l'analyse thermographique (ATG) et par la spectroscopie infrarouge à transformée de Fourier (FTIR). Les propriétés hygrothermiques du matériau chanvre-amidon avec et sans traitement de fibres sont également étudiées. Ces propriétés comprennent la courbe d'isotherme de sorption, la perméabilité à la vapeur d'eau, la conductivité thermique et la capacité tampon hydrique du matériau. / In order to control energy consumption, several European countries including France, adopted regulations to optimize the energy performance of the building envelope. This fact could increase the level of indoor relative humidity which can affect the health of the occupants and causes material damage. Using eco-friendly materials such as hemp concrete which can buffer indoor moisture levels might contribute to maintain high indoor comfort.The main purpose of this thesis is to optimise and characterize a construction material made of hemp hurds and wheat starch binder.The formulation of the hemp-starch is studied by varying starch/hemp ratio and its impact on mechanical properties. Sound absorption coefficient is measured for optimal composition. To improve the adhesion between hemp fibers and starch matrix, alkali treatment with sodium hydroxide was performed to solubilize hemicelluloses and lignin seal surrounding the cellulose bundle in the first step and then a silane coupling agent (3-glycidyloxypropyl) trimethoxylsilane was used to provide a stable bond between hemp fibres and starch matrix. The influence of the treatments were investigated by scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) and attenuated total reflectance spectroscopy (ATR). After the treatments, mechanical properties of hemp-starch material were studied.Hygrothermal properties of hemp-starch material with and without fibre treatment were also measured. These properties include sorption isotherm curve, water vapour permeability, thermal conductivity and moisture buffering value.

La loupe de thuya joue un rôle économique et social important pour le secteur artisanal marocain. Ces dernières décennies, pour répondre à une forte demande, le bois de la loupe de thuya a été surexploité entraînant une dégradation importante des forêts de thuya marocaines. Une réponse possible à cette problématique, à court terme, consiste à limiter les déchets d'usinage. Cette voie d'investigation passe par la caractérisation du matériau et notamment l'identification de son réseau de symétries matérielles. L'objectif de ce travail est donc de caractériser le bois de la loupe de thuya (Tetraclinis articulata (vahl) Masters) dont le comportement mécanique n'a pas été étudié jusqu'à présent. Pour atteindre cet objectif, on passe tout d'abord par une caractérisation multi-échelle. A l'échelle globale, la caractérisation est réalisée en étudiant la structure interne d'une loupe entière par tomographie X, et plus particulièrement la distribution des excroissances foncées caractéristiques de la loupe. Cette étude macroscopique est complétée, à l'échelle microscopique, par une analyse comparative de coupes anatomiques de bois de thuya et de loupe. À l'échelle du matériau, le bois de la loupe est caractérisé en étudiant la dispersion de sa rigidité par une méthode ultrasonore par contact direct. L'étude plus approfondie du comportement mécanique a nécessité la mise au point d'une méthode ultrasonore par contact direct sur des échantillons sphériques afin d'identifier les symétries matérielles d'un matériau. Cette méthode, appliquée au bois de la loupe de thuya, montre que la loupe a un comportement isotrope transverse. Par conséquent, il ne présente pas les mêmes symétries naturelles que le bois présent dans le tronc du même arbre. Cette méthode ne permet pas d'obtenir la matrice de rigidité complète : dans le cas d'un matériau orthotrope, elle donne accès aux 3 termes diagonaux de la matrice et à 3 combinaisons linéaires des 6 autres termes. Pour identifier complètement la matrice de rigidité, nous proposons, en perspective, l'utilisation de la Spectroscopie Ultrasonore Résonante (RUS). Le couplage de la méthode ultrasonore par contact direct développée et de la méthode RUS permettra de déterminer les symétries matérielles et la matrice de rigidité sur le même échantillon. Enfin, des coupes obtenues par tomographie X peuvent être superposées aux graphes de rigidité pour analyser la relation entre la structure interne et le comportement élastique de la loupe de thuya. / The wood of thuja burr plays an important economic and social role for the Moroccan artisanal sector. In last decades, as demand increased, thuja burr was overexploited resulting in an important degradation of Moroccan thuja forests. One possible solution, in the short term, consists in limiting waste machining. This approach requires the characterization of the material, especially of its materiel symmetries. This work aims thus at characterizing the wood of thuja burr (Tetraclinis articulata (Vahl) Masters), that was little studied up to now. First, a multi-scale characterization is proposed. At the global scale, the internal structure of an entire thuja is observed using X ray tomography, especially the distribution of dark growth elements typical of thuja burr. This macroscopic characterization is completed, at the microscopic scale, by a comparative analysis of anatomical microsections of thuja wood and thuja burr. At the material scale, the dispersion of the thuja burr stiffness is observed using a direct contact ultrasonic method. In order to progress further in the study of the mechanical anisotropy, a direct contact ultrasonic method for spherical samples is developed allowing to identify material symmetries. By applying this method to the thuja burr wood, a transverse isotropic behaviour is observed. Hence thuja burr wood does not exhibit the same natural symmetries as what is found in the trunk of the same tree. However, this method does not yield the complete stiffness matrix. In the case of an orthotropic material, it gives the access to 3 diagonal terms of the matrix and 3 linear combinations of the six other terms. The use of Resonance Ultrasound Spectroscopy (RUS) is proposed to identify the stiffness matrix completely: the coupling of the direct contact ultrasonic method developed and RUS method allows to determine the symmetries and stiffness matrix on the same sample. Finally, scanned images obtained by X-ray tomography can be superimposed on stiffness graphs to analyze the relationship between the internal structure and the elastic behavior of thuja burr.

[pt] O Ácido Húmico (AH) é uma fração orgânica obtida em solos, corpos hídricos bem como em matrizes carbonáceas. Nos últimos anos o interesse associado a esta substância vem crescendo progressivamente à medida que novas aplicações são descobertas, tais como: fertilizantes, recuperação de áreas degradadas e tratamento de efluentes contaminados com metais. As principais características dos AH são dependentes do método de extração e da matriz escolhida, posto que se pode extraí-lo de uma ampla gama de matérias primas, assim como por meio de diferentes métodos. Dentro deste contexto, o objetivo principal do presente trabalho pretende avaliar o potencial de extração de ácido húmico a partir de diferentes precursores carbonáceos. Foram utilizadas três matrizes carbonáceas distintas: rejeito de carvão mineral (RCM), coque mineral (CM) e coque verde de petróleo (CVP). Além deste estudo experimental foram apresentados alguns resultados de estudo semelhante disponível na literatura. O método de extração utilizado foi adaptado de Trompowski et al (2005), e a caracterização foi feita utilizando-se técnicas de ICP-OES, CNHS, MEV/EDS, FTIR e Difração de Raio-X. A eficiência da extração, em termos de recuperação em massa, variou, significativamente, em função do método adotado, sendo os melhores resultados associados ao rejeito de carvão mineral (17,0 porcento), ao passo que a menor eficiência está relacionada ao coque verde de petróleo, após destilação (0,2 porcento). A extração a partir do coque verde de petróleo, como recebido, é inviável em função da sua imiscibilidade com a solução de ácido nítrico. Os resultados obtidos a partir do FTIR foram satisfatórios para todos os AH analisados, apresentando bandas características de AH e compatíveis com o indicado na literatura. Os resultados da análise de ICP-OES apresentaram baixa presença de metais e elementos traços para o AH oriundo do coque mineral. No que diz respeito ao ácido húmico extraído do rejeito de carvão mineral, que apresentou a maior concentração inicial de metais, principalmente ferro, foi implementado, com sucesso, uma purificação utilizando ácido nítrico. Com base nos resultados obtidos é possível afirmar que a utilização de diferente precursores carbonosos permitiu a extração de AH com características semelhantes aqueles citados na literatura e extraídos de outras fontes. / [en] The humic acid (HA) is an organic fraction that can be found in soil and watercourses as well as in carbonaceous matrices. In recent years the interest associated with this substance has been growing steadily as new applications are discovered, such as fertilizers, remediation of degraded areas and treatment of wastewater contaminated with metals. The main features of HA are dependent on the method of extraction and the chosen matrix, since it can be extract from a wide range of raw materials, as well as by different methods. Within this context, the main objective of this work is related to an assessment of the potential of extracting humic acid from different carbonaceous precursors. three different carbonaceous matrices were used: coal tailings (RCM), coke (CM) and green petroleum coke (CVP). Besides this experimental study some results of a similar study available in the literature were presented. The extraction method used was adapted from Trompowski et al, and the characterization was done using ICP- OES techniques, CNHS, MEV / EDS and FTIR. The extraction efficiency, in terms of mass recovery, significantly varied depending on the method used, the best results being associated with coal tailings (17.0 percent), while lower efficiency relates to the calcinated petrocoke after distillation (0.2 percent). The extraction from green petroleum coke, as received, is unfeasible due to its immiscibility with the nitric acid solution. The results obtained from FTIR were satisfactory for all the HA analyzed, displaying bands consistent with those from HA and compatible with bands shown in the literature. The results of the analysis of ICP-OES showed a low presence of metals and trace elements coming from the HA for coke. With respect to the extracted humic acid from coal tailings, which showed the highest initial concentration of metals, particularly iron, was successfully implemented, a purification with nitric acid. Based on the results obtained it can be stated that the use of different carbonaceous precursors allowed the extraction of humic acid with similar characteristics as cited in the literature and those obtained from other sources.

Bien que la maçonnerie en pierre soit une technique de construction ancestrale,le comportement mécanique de ce type de construction reste encore aujourd’hui méconnu.En conséquence, la réglementation concernant ces ouvrages est restrictive et considèredes marges de sécurité importantes, qui conduisent à un surdimensionnement de cetype de structure. Ce projet de recherche vise à développer un code de calcul adapté à l’étudede structures maçonnées, utilisable en bureau d’études afin d’aider les ingénieurs qui nepossèdent pas d’outils adaptés aux ouvrages maçonnés sur lesquels s’appuyer.Le logiciel de calcul aux éléments discrets LMGC90 a été choisi pour sa capacité à représenterle caractère discontinu de la maçonnerie. Une loi d’interface cohésive enmode mixte (I+II) aété mise au point afin de prendre en compte l’endommagement progressif et la dissipationd’énergie associés au comportement quasi-fragile des joints de mortier. Un protocole expérimentalpermettant d’estimer l’ensemble des paramètres cohésifs et frictionnels des jointsde mortier a également été mis au point.Le modèle numérique proposé est confronté à deux essais expérimentaux menés sur desmurs sollicités en cisaillement sous deux conditions aux limites différentes. L’analyse desrésultats obtenusmet en avant l’insuffisance de la loi deMode II proposée à décrire précisémentle comportement en cisaillement dans certains cas. Des voies d’amélioration concernantla modélisation sont donc proposées, comprenant notamment l’étude précise du couplageentre l’endommagement (comportement cohésif) et le comportement frictionnel desjoints sollicités en cisaillement. / Stone masonry is an age-old constructive technique, nevertheless the mechnicalbehavior of this type of construction is still misunderstood. Consequently, standardsfor masonry structural design are very conservative and overestimate design of this kind ofstructures. Moreover, engineers cannot rely on suitable design code to assess masonry buildings.This research project aims to develop a design code suitable for structural masonrydesign to help engineers.Discrete element code LMGC90 was picked for its capacity to take into account masonrydiscontinuities. A mixed mode I+II cohesive interface law is established in order to considerprogressive damage and energy dissipation associated to quasi-brittle behaviour of mortarjoints. An experimental procedure was also carried out to estimate the whole cohesive andfrictional parameters ofmortar joints.The proposed numerical model is confronted to two experimental tests on shear masonrywalls under two different boundary conditions. The results of the analysis shows that thedeveloped model fails at reproducing precisely the shear behaviour especially when the normalstress to the joint strongly increses during the test. Thus we discuss on the Mode II law,and more specifically on the separation of frictional and cohesive behaviours which must beresponsible for the deficient results.

La peau est un organe capable de se régénérer et de cicatriser. Elle constitue la première barrière de protection de notre organisme contre les agressions physico-chimiques extérieures. Depuis plusieurs décennies des recherches ont été menées pour maîtriser la culture du derme pour plusieurs applications telles que la greffe des grands brulés. L’aspect technologique de ce domaine a fait l’objet de plusieurs travaux. Dans les années 2000, l'équipe de notre laboratoire a proposé la méthode de culture du derme associée à des microsystèmes en silicium. C’est l’unique méthode actuelle qui permet la mesure des forces isométrique du derme équivalent lors de sa culture.Dans une première étude, nous avons proposé des nouvelles méthodes de mesure des forces isométriques qui s’exercent dans des peaux reconstruites en culture entre deux lames de silicium afin de fabriquer un bio-dispositif miniaturisé à faible coût. Ainsi, les dimensions optimales ont été calculées et des nouvelles lames ont été fabriquées. L’optimisation que nous avons retenue est relative à l’amélioration de la sensibilité de la mesure des forces. Afin de quantifier le fléchissement de lames due aux forces isométriques appliquées par le derme en culture, nous avons opté pour la mesure des déplacements des lames sous l’effets des forces isométriques, à l’aide d’ondes acoustiques de surface (SAW). Ce choix se justifie par la simplicité de l’intégration des transducteurs interdigités qui génèrent les ondes acoustiques, de la possibilité d’utiliser une interrogation sans fils et la réalisation physique de l’intercorrélation des ondes générées.A l’aide de simulation nous avons identifié les déformations des ondes et les écarts de fréquence qu’elles provoquent. En effet, la dissymétrie de la courbe d’intercorrélation des signaux transmis et reçus, par les transducteurs interdigités, est intiment liée à l’écart de fréquence de l’onde reçue. Nous avons démontré que le fléchissement engendre bien la dissymétrie dans l’axe du temps qui peut être mesurée plus précisément dans les limites d‘échantillonnage. Deux démonstrateurs sont modélisés et fabriqués dans la salle blanche afin de valider l’instrumentation et le principe de transduction d’un signal chirpé avec une onde acoustique de surface. Les résultats obtenus montrent que la méthode de mesure à l’aide d’une onde acoustique nous permet de faire de mesure de force mais dans une gamme d’intensité plus élevée que celle attendue. Par la suite, nous avons étudié la méthode de mesure de forces par les capteurs à base de piézorésistances. Sachant que la technique est basée sur la variation de résistivité du matériau déformé, nous avons décidé de replacer les grilles de lame prévue pour l’accrochage du derme en culture par le matériau piézorésistif implanté sur les micro poutres. Afin d’améliorer la résolution de détection de faibles forces une série de calcul et de simulations de la position et les dimensions du matériau piézorésistif et des micropoutres sont effectués et présentés. Une autre étude que nous avons menée en parallèle concerne le développement d’une instrumentation embarquée permettant de suivre la croissance du derme en culture basé sur un système de vision. Vu les conditions strictes de notre cahier de charges qui exigeait la portabilité et l’autonomie de système final, nous avons prévu le développement d’un système de vision embarqué basé sur un module de caméra et une carte FPGA. La caméra à haute définition montée sur le système de boite de culture finale avec un objectif permet de prendre des images de fluorescences des cellules en culture. / The skin is an organ which can regenerate and heal. It is the first shield of protection of our body against external physico-chemical aggression. For several decades, researches have been conducted to control the dermis culture for several applications such as grafting large burns. The technological aspect of this area has been the subject of several works. In the 2000s, the team of our laboratory proposed the dermis culture method associated with silicon microsystems. This is the only current method that allows the measurement of isometric forces of the equivalent dermis during its culture.In a first stage of study, in order to produce a miniaturized and low-cost bio-device, we proposed new methods to measure isometric forces in reconstructed skins in culture between two silicon beams. Thus, the optimal dimensions were calculated and new beams were fabricated. The chosen optimization is related to improve the sensitivity of the force measurement. To quantify the deflection of the beams due to the isometric forces applied by the dermis in culture, we opted for the measurement of the displacements of the beams under the influence of the isometric forces by using surface acoustic waves (SAW). This choice is justified by the simplicity of the integration of the interdigital transducers (IDT) that generate the SAW, the possibility of using a wireless interrogation and the physical realization of the cross-correlation of the generated waves.Using simulation, we have identified the frequency deviations caused by wave deformations. Indeed, the dissymmetry of the cross-correlation curve of the signals generated and received by IDT is closely related to the frequency deviation of the received wave. We have evidenced that the beam deflection generates the dissymmetry in the time axis which can be measured more precisely within the limits of sampling. Two demonstrators were designed and manufactured in the clean room to validate the instrumentation and the principle of transducing a chirped signal with a SAW. The obtained results show that the proposed SAW-based force measuring method allows us to measure force, but in a higher intensity range than expected. Subsequently, we studied the method of force measurement by piezoresistors. Considering that the technique is based on the variation of resistivity of the deformed material, we decided to replace the silicon grids provided for the attachment of the dermis in culture by the piezoresistive material implanted on the silicon micro-beams. To improve the low-resolution detection, a series of calculations and simulations of the positions and the dimensions of the piezoresistive material and the micro-beams have been carried out and presented. Another study that we conducted in parallel concerns the development of an on-board instrumentation to monitor the growth of the dermis in culture based on a vision system. Considering of the strict conditions of our specifications that required the portability and autonomy of the final system, we developed an embedded vision system based on a camera module and a FPGA card. The high definition camera mounted on the system of final culture box with a lens allows to take fluorescence images of cells in culture.

Made available in DSpace on 2016-06-02T20:28:30Z (GMT). No. of bitstreams: 1 6065.pdf: 865751 bytes, checksum: 22466d8659637f2282b6be8b0adb5a33 (MD5) Previous issue date: 2014-03-13 / Financiadora de Estudos e Projetos / This work is divided into two parts. In the first part, our goal is to present the theory of Hardy Spaces Hp(Rn), which coincides with the Lebesgue space Lp(Rn) for p > 1, is strictly contained in Lp(Rn) if p = 1, and is a space of distributions when 0 < p < 1. When 0 < p ^ 1, the Hardy spaces offers a better treatment involving harmonic analysis than the Lp spaces. Among other results, we prove the maximal characterization theorem of Hp, which gives equivalent definitions of Hp, based on different maximal functions. We will proof the atomic decom¬position theorem for Hp, which allow decompose any distribution in Hp to be written as a sum of Hp-atoms (measurable functions that satisfy certain properties). In this step, we use the strongly the of Whitney decomposition and generalized Calderon-Zygmund decomposition. In the second part, as a application, we will prove that nonlinear quantities (such as the Jacobian, divergent and rotational defined in Rn) identied by the compensated compactness theory belong, under natural conditions, the Hardy spaces. To this end, in addition to the results seen in the first part, will use the results as Sobolev immersions theorems ans the inequality Sobolev-Poincare. Furthermore, we will use the tings and results related to the context of differential forms. / Esse trabalho está dividido em duas partes.Na primeira, nosso objetivo e apresentar os espaços de Hardy Hp(Rn), o qual coincide com os espaços Lp(Rn), quando p > 1, esta estritamente contido em Lp(Rn) se p = 1, e e um espaço de distribuições quando 0 < p < 1. Quando 0 < p < 1, os espaços de Hardy oferecem um melhor tratamento envolvendo analise harmônica do que os espaços Lp(Rn). Entre outros resultados, provamos o teorema da caracterização maximal de Hp, o qual fornece varias, porem equivalentes, formas de caracterizar Hp, com base em diferentes funcões maximais. Demonstramos o teorema da decomposição atômica para Hp, 0 < p < 1, que permite decompor qualquer distribuição em Hp como soma de Hp-atomos (funções mensuráveis que satisfazem certas propriedades). Nessa etapa, usamos fortemente a de- composição de Whitney e a decomposto de Calderon-Zygmund generalizada. Na segunda parte, como uma aplicação, provamos que quantidades não-lineares (como o jacobiano, divergente e o rotacional definidos em Rn), identificadas pela teoria compacidade compensada pertencem, em condições naturais, aos espaços de Hardy. Para tanto, além dos resultados visto na primeira parte, usamos outros como os Teoremas de Imersões de Sobolev, a desigualdade de Sobolev-Poincaré. Usamos ainda, definições e resultados referentes ao contexto de formas diferenciais.