A presente dissertação tem como objetivo analisar as permanências e os afastamentos de alunos do Colégio de Aplicação da UFRGS, da turma Alfa - 1/2001, ao longo de sua trajetória escolar entre o Ensino Fundamental e Ensino Médio. Observou-se que um número significativo de alunos dessa turma se transferiu da escola sendo que os motivos que provocaram essas transferências foram reprovação, falta de adaptação à escola e os turnos dobrados. Em consonância com as teorizações dos Estudos Culturais, de inspiração pós-estruturalista, entendo que as permanências ou os afastamentos de alunos não se tratam apenas de um desenrolar natural das circunstâncias da vida de cada aluno, mas estão implicados em processos de in/exclusão que acabam produzindo as possibilidades de permanência de alguns e as transferências de outros alunos. Apoiei-me em conceitos como categoria social aluno e in/exclusão para compreender como se dá a inserção do aluno, ingressante por sorteio público na instituição, e os processos de diferenciação e normalização decorrentes do convívio com as práticas escolares do CAp/UFRGS. Como estratégias metodológicas foram utilizadas entrevistas e questionários com membros da equipe diretiva, professores e alunos da turma Alfa - 1/2001, e análise de documentos da instituição. No que se refere às unidades analíticas, estas se constituíram das problematizações entre os objetivos de formação dos alunos do CAp/UFRGS, constante em documentos e nas narrativas da equipe diretiva, professores e alunos e as novas populações de crianças e jovens que ingressam por sorteio público na instituição. Tendo como base as análises realizadas pode-se afirmar, mesmo que provisoriamente, que no CAp/UFRGS os alunos ingressantes por sorteio público vão, gradativamente, sendo selecionados por critérios relacionados ao desempenho escolar e adaptação às práticas pedagógicas da escola. Acredito que este estudo poderá, além de problematizar as práticas que desencadeiam uma seleção entre os alunos e produzem as possibilidades de permanência e de transferências, auxiliar em discussões para que esta escola, que tem como uma das suas finalidades pensar e criar novas práticas pedagógicas e metodológicas para auxiliar outras redes públicas de ensino, repensar o atendimento a ser prestado aos novos alunos que nesses novos tempos ingressam em suas salas de aula. / This thesis aims to analyze the permanence and clearances Application College students from UFRGS, Alpha I 2001 class along their trajectory between the Primary and Secondary Education. It was observed that a significant number of students in this class has moved the school and that the reasons that caused these transfers were failing, failure to adapt to school and double shifts. In line with the theories of cultural studies, post-structuralist inspiration, I understand that the stays or removals of students are not just a natural course of life circumstances of each student, but are involved in in / exclusion processes that end up producing the remaining opportunities for some and transfers of other students. I leaned on concepts such as social class and student in / exclusion to understand how is the introduction of students, undergraduate students by public lottery in the institution and the differentiation and standardization processes resulting from the interaction with school practices CAp / UFRGS. As methodological strategies were used interviews and questionnaires with members of the management team, teachers and students of the Alfa class I in 2001, and analysis of the institution's documents. With regard to analytical units in these consisted of problematizations between training objectives of the CAp / UFRGS students, constant in documents and narratives of the management team, teachers and students and new populations of children and young people entering by public lottery the institution. Based on the analyzes it can be stated, however temporary that in CAp / UFRGS commencing students by public lottery will gradually being selected by criteria related to school performance and adaptation to school pedagogical practices. I believe this study may, in addition to questioning the practices that trigger a selection among students and produce the possibility of staying permanently and transfers, assist in discussions to this school, which has as one of its purposes think and create new teaching practices and methodological to help other public schools, rethink the assistance to be provided to new students who enter these new times in their classrooms.

A presente dissertação tem como objetivo analisar as permanências e os afastamentos de alunos do Colégio de Aplicação da UFRGS, da turma Alfa - 1/2001, ao longo de sua trajetória escolar entre o Ensino Fundamental e Ensino Médio. Observou-se que um número significativo de alunos dessa turma se transferiu da escola sendo que os motivos que provocaram essas transferências foram reprovação, falta de adaptação à escola e os turnos dobrados. Em consonância com as teorizações dos Estudos Culturais, de inspiração pós-estruturalista, entendo que as permanências ou os afastamentos de alunos não se tratam apenas de um desenrolar natural das circunstâncias da vida de cada aluno, mas estão implicados em processos de in/exclusão que acabam produzindo as possibilidades de permanência de alguns e as transferências de outros alunos. Apoiei-me em conceitos como categoria social aluno e in/exclusão para compreender como se dá a inserção do aluno, ingressante por sorteio público na instituição, e os processos de diferenciação e normalização decorrentes do convívio com as práticas escolares do CAp/UFRGS. Como estratégias metodológicas foram utilizadas entrevistas e questionários com membros da equipe diretiva, professores e alunos da turma Alfa - 1/2001, e análise de documentos da instituição. No que se refere às unidades analíticas, estas se constituíram das problematizações entre os objetivos de formação dos alunos do CAp/UFRGS, constante em documentos e nas narrativas da equipe diretiva, professores e alunos e as novas populações de crianças e jovens que ingressam por sorteio público na instituição. Tendo como base as análises realizadas pode-se afirmar, mesmo que provisoriamente, que no CAp/UFRGS os alunos ingressantes por sorteio público vão, gradativamente, sendo selecionados por critérios relacionados ao desempenho escolar e adaptação às práticas pedagógicas da escola. Acredito que este estudo poderá, além de problematizar as práticas que desencadeiam uma seleção entre os alunos e produzem as possibilidades de permanência e de transferências, auxiliar em discussões para que esta escola, que tem como uma das suas finalidades pensar e criar novas práticas pedagógicas e metodológicas para auxiliar outras redes públicas de ensino, repensar o atendimento a ser prestado aos novos alunos que nesses novos tempos ingressam em suas salas de aula. / This thesis aims to analyze the permanence and clearances Application College students from UFRGS, Alpha I 2001 class along their trajectory between the Primary and Secondary Education. It was observed that a significant number of students in this class has moved the school and that the reasons that caused these transfers were failing, failure to adapt to school and double shifts. In line with the theories of cultural studies, post-structuralist inspiration, I understand that the stays or removals of students are not just a natural course of life circumstances of each student, but are involved in in / exclusion processes that end up producing the remaining opportunities for some and transfers of other students. I leaned on concepts such as social class and student in / exclusion to understand how is the introduction of students, undergraduate students by public lottery in the institution and the differentiation and standardization processes resulting from the interaction with school practices CAp / UFRGS. As methodological strategies were used interviews and questionnaires with members of the management team, teachers and students of the Alfa class I in 2001, and analysis of the institution's documents. With regard to analytical units in these consisted of problematizations between training objectives of the CAp / UFRGS students, constant in documents and narratives of the management team, teachers and students and new populations of children and young people entering by public lottery the institution. Based on the analyzes it can be stated, however temporary that in CAp / UFRGS commencing students by public lottery will gradually being selected by criteria related to school performance and adaptation to school pedagogical practices. I believe this study may, in addition to questioning the practices that trigger a selection among students and produce the possibility of staying permanently and transfers, assist in discussions to this school, which has as one of its purposes think and create new teaching practices and methodological to help other public schools, rethink the assistance to be provided to new students who enter these new times in their classrooms.

The single row layout problem (SRLP) is a specially structured instance of the classical facility layout problem, especially used in flexible manufacturing systems. The SRLP consists of finding the most efficient arrangement of a given number of machines along one side of the material handling path with the purpose of minimising the total weighted sum of distances among all machine pairs. To reflect real manufacturing situations, a minimum space (so-called clearances) between machines may be required by observing technological constraints, safety considerations and regulations. This thesis intends to outline the different concepts of clearances used in literature and analyse their effects on modelling and solution approaches for the SRLP. In particular the special characteristics of sequence-dependent, asymmetric clearances are discussed and finally extended to large size clearances (machine-spanning clearances). For this, adjusted and novel model formulations and solution approaches are presented. Furthermore, a comprehensive survey of articles published in this research area since 2000 is provided which identify recent developments and emerging trends in SRLP.

In real life, immediately after joint replacement, the artificial joint is actually bathed in blood (and clotted blood) instead of synovial fluid. Blood contains large molecules and cells of size ~ 5 to 20 μm suspended in plasma and considered to be a non-Newtonian (pseudoplastic) fluid with density of 1060 Kg/m³ and viscosity ~ 0.01 Pas at shear rates of 3000 s⁻¹ (as obtained in this work). The effect of these properties on friction and lubrication is not fully understood and, so far to our knowledge, hardly any studies have been carried out regarding friction of metal-on-metal bearings with various clearances in the presence of lubricants such as blood or a fluid containing macromolecules such as hyaluronic acid (HA) which is a major component of synovial fluid increasing its viscosity and lubricating properties. In this work, therefore, we have investigated the frictional behaviour of a group of Smith and Nephew Birmingham Hip Resurfacing implants with a nominal diameter of 50mm and diametral clearances in the range ~ 80 μm to 300 μm, in the presence of blood (clotted and whole blood), a combination of bovine serum (BS) with hyaluronic acid (HA) and carboxymethyl cellulose (CMC, as gelling agent) adjusted to a range of viscosities (~0.001-0.2 Pas), and bovine serum with CMC adjusted to a similar range of viscosities. These results suggested that reduced clearance bearings have the potential to generate high friction especially in the presence of blood which is indeed the in vivo lubricant in the early weeks after implantation. Friction factors in higher clearance bearings were found to be lower than those of the lower clearance bearings using blood as the lubricant. Similar trends, i.e. increase in friction factor with reduction in diametral clearance, were found to be also the case using a combination of BS+CMC or BS+HA+CMC as lubricants having viscosities in the range 0.1-0.2 and 0.03-0.14 Pas, respectively. On the other hand, all the lubricants with lower viscosities in the range 0.001-0.0013 and 0.001-0.013 Pas for both BS+CMC and BS+HA+CMC, respectively, showed the opposite effect, i.e. caused an increase in friction factor with increase in diametral clearance. Another six large diameter (50mm nominal) BHR deflected prostheses with various clearances (~ 50-280μm after cup deflection) were friction tested in vitro in the presence of blood and clotted blood to study the effect of cup deflection on friction. It was found that the biological lubricants caused higher friction factors at the lower diametral clearances for blood and clotted blood as clearance decreased from 280μm to 50μm (after deflection). The result of this investigation has suggested strongly that the optimum clearance for the 50 mm diameter MOM BHR implants to be ≥150μm and <235μm when blood lubricant used, so as to avoid high frictions (i.e. avoid friction factors >0.2) and be able to accommodate a mixed lubrication mode and hence lower the risk of micro- or even macro-motion specially immediately after hip implantation. These suggested optimum clearances will also allow for low friction (i.e. friction factors of <0.2-0.07) and reasonable lubrication (dominantly mixed regime) for the likely cup deflection occurring as a result of press-fit fixation.

The natural hip joint in healthy people has a very low friction with very little (or no) wear. It works as a dynamically loaded bearing and is subjected to about 1-2 million cycles of loading per year. The applied load is the body weight which is tripled when walking and even higher during other activities such as running and jumping. Unfortunately these joints are not always healthy due to various causes such as fractures or disease leading to severe pain which necessitates joint replacement. Currently, the orthopaedic industries are working towards developing an ideal artificial hip joint with low wear, low friction, good lubrication, better fixation/stability and biocompatibility. Many different designs and materials have been investigated with some promising new implants which can be used depending on patients' individual need (large or small joint), activity and age. In this work, two types of artificial hip joints were tested for friction and lubrication studies: Metal-on-Metal (MoM) Biomet hip resurfacing ReCaps with large diameters (>35-60 mm) and different diametral clearances (~ 60-350 µm), and Zirconia Toughened Alumina (ZTA) heads against carbon-fibre-reinforced poly-ether-ether ketone (CFR PEEK) cups with different diameters (>35-60 mm) and diametral clearances (60-1860 µm). Seven serum-based lubricants with different viscosities were used with and without carboxy methyl cellulose (CMC) additions as gelling agent to increase viscosity depending on the CMC content. The maximum load applied was 2000 N for the stance phase with a minimum load of 100 N for the swing phase. A Pro-Sim friction hip simulator was used to investigate the frictional torque generated between the articulating surfaces so as the friction factor can be calculated. Stribeck analysis was then employed to assess the mode of lubrication. For the metal-on-metal hip resurfacing joints, the friction factors were in the range 0.03-0.151 and those for the ZTA ceramic heads versus CFR PEEK cups were in the range 0.006-0.32. Stribeck analyses showed mainly mixed lubrication for both MoM and ZTA ceramic-on-CFR PEEK joints. The experimental results were in agreement with most of the theoretical calculations suggesting mixed lubricating regimes at low viscosities and moving on to fluid film lubrication at higher viscosities. Joints with larger-diameters, lower clearances and lower surface roughness exhibited a higher lambda ratio suggesting improved lubrication. Viscosity flow curves for the serum-based lubricants having viscosity ≤ 0.00524 Pas showed non-linear relationship between viscosity and shear rate indicating non-Newtonian flow with pseudoplastic or shear-thinning characteristic, i.e. viscosity decreased as shear rate increased up to shear rates of ~ 1000 s⁻¹. However, at shear rates greater than 1000 s⁻¹ Newtonian flow became dominant with almost constant viscosity, i.e. a linear relationship between shear stress and shear rate. On the other hand, viscosity flow curves for the lubricants with viscosity ≥ 0.0128 Pas showed non-Newtonian behaviour up to a shear rate of 3000 s⁻¹ with shear-thinning characteristic.

Le développement de méthodes in vitro fiables et prédictives représente à l’heure actuelle un véritable défi. En effet, la demande en méthodes alternatives à l’expérimentation animale n’a cessé de croître ces dernières années du fait de la mise en place de législations limitant par considérations éthiques l’utilisation de ces modèles in vivo. De plus, ce besoin a été renforcé par le règlement européen REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) imposant aux industriels de valider l’innocuité de nombreuses substances déjà commercialisées. Toutefois, les modèles in vitro classiques consistant en la culture simple de cellules en monocouche dans des boîtes de Petri ne permettent pas de conserver les propriétés initiales de ces cellules et de retranscrire les conditions et l’environnement cellulaire des organes in vivo. Le développement de méthodes alternatives in vitro prédictives s’avèrent donc crucial en particulier pour mimer le fonctionnement de deux organes : l’intestin et le foie. En effet, ces deux organes sont largement impliqués dans les processus d’Absorption, Distribution, Métabolisme et Excrétion (ADME) de la plupart des xénobiotiques ingérés. C’est pour ces raisons que nous avons testé la faisabilité de l’une de ces méthodes in vitro alternative permettant d’associer une barrière intestinale à la culture dynamique de cellules hépatiques au sein de microsystèmes dans le cadre de ce doctorat. Cette coculture est effectuée au sein du dispositif appelé IIDMP (Integrated Insert in a Dynamic Microfluidic Platform). Nous avons décidé de tester d’une part l’influence de la culture dynamique et d’autre part d’éventuelles interactions entre les cellules intestinales et hépatiques sur la fonctionnalité et l’activité métabolique de ces deux types cellulaires. Les résultats obtenus durant ce doctorat ont permis d’atteindre 4 objectifs :- Développer un dispositif fiable en termes de fonctionnalité (fluidique, robustesse…).- Mettre en évidence l’innocuité du dispositif lorsque des cellules de lignée et primaires y étaient cultivées.- Démontrer les avantages de l’utilisation de ce dispositif comparativement à l’utilisation de modèles classiques in vitro, en particulier avec des cellules de lignée.- Démontrer que l’utilisation de ce dispositif permettait de mettre en évidence des phénomènes d’interactions entre cellules intestinales et hépatiques notamment sur l’activité du CYP1A2 des hépatocytes qu’ils soient issus d’une lignée ou de cultures primaires. / The development of reliable and predictive in vitro methods is a real challenge. Indeed, the demand for alternative methods to animal experimentation has been growing in recent years due to the introduction of legislation limiting the use of these models in vivo by ethical considerations. Moreover, this need was amplified by regulations such as the European REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) requiring the safety validation of many substances. However, the conventional in vitro model consisting in a simple cell culture monolayer in Petri dishes does not preserve the initial properties of these cells and does not mimic the conditions of the cellular environment and organs in vivo. The development of alternative in vitro predictive methods is crucial especially to mimic the working of two organs: the intestine and liver. Indeed, these two organs are involved in the process of Absorption, Distribution, Metabolism and Excretion (ADME) of most xenobiotics ingested.We propose in this thesis to test the feasibility of one of these in vitro alternative methods allowing the association between an intestinal barrier and the dynamic culture of hepatic cells in microsystems in a device called IIDMP (Integrated Dynamic Insert in a Microfluidic Platform). We tested the influence of the flow of culture and possible interactions between intestinal and liver cells on the function and metabolic activity of these two cell types.Then, we demonstrated that : - This device is reliable in terms of global functionality (fluid, robustness ...).- This device did not injury the integrity of the cell line and primary cells.- The use of this device has many advantages when compared with the use of conventional in vitro models, especially with cells line.- The use of this device highlights phenomena of interaction between hepatic and intestinal cells as an increase of the CYP1A2 activity of HepG2 C3A and human primary hepatocytes.

In real life, immediately after joint replacement, the artificial joint is actually bathed in blood (and clotted blood) instead of synovial fluid. Blood contains large molecules and cells of size ~ 5 to 20 2m suspended in plasma and considered to be a non-Newtonian (pseudoplastic) fluid with density of 1060 Kg/m3 and viscosity ~ 0.01 Pas at shear rates of 3000 s-1 (as obtained in this work). The effect of these properties on friction and lubrication is not fully understood and, so far to our knowledge, hardly any studies have been carried out regarding friction of metal-on-metal bearings with various clearances in the presence of lubricants such as blood or a fluid containing macromolecules such as hyaluronic acid (HA) which is a major component of synovial fluid increasing its viscosity and lubricating properties. In this work, therefore, we have investigated the frictional behaviour of a group of Smith and Nephew Birmingham Hip Resurfacing implants with a nominal diameter of 50mm and diametral clearances in the range ~ 80 2m to 300 2m, in the presence of blood (clotted and whole blood), a combination of bovine serum (BS) with hyaluronic acid (HA) and carboxymethyl cellulose (CMC, as gelling agent) adjusted to a range of viscosities (~0.001-0.2 Pas), and bovine serum with CMC adjusted to a similar range of viscosities. These results suggested that reduced clearance bearings have the potential to generate high friction especially in the presence of blood which is indeed the in vivo lubricant in the early weeks after implantation. Friction factors in higher clearance bearings were found to be lower than those of the lower clearance bearings using blood as the lubricant. Similar trends, i.e. increase in friction factor with reduction in diametral clearance, were found to be also the case using a combination of BS+CMC or BS+HA+CMC as lubricants having viscosities in the range 0.1-0.2 and 0.03-0.14 Pas, respectively. On the other hand, all the lubricants with lower viscosities in the range 0.001-0.0013 and 0.001-0.013 Pas for both BS+CMC and BS+HA+CMC, respectively, showed the opposite effect, i.e. caused an increase in friction factor with increase in diametral clearance. Another six large diameter (50mm nominal) BHR deflected prostheses with various clearances (~ 50-2802m after cup deflection) were friction tested in vitro in the presence of blood and clotted blood to study the effect of cup deflection on friction. It was found that the biological lubricants caused higher friction factors at the lower diametral clearances for blood and clotted blood as clearance decreased from 2802m to 502m (after deflection). The result of this investigation has suggested strongly that the optimum clearance for the 50 mm diameter MOM BHR implants to be ¿1502m and <2352m when blood lubricant used, so as to avoid high frictions (i.e. avoid friction factors >0.2) and be able to accommodate a mixed lubrication mode and hence lower the risk of micro- or even macro-motion specially immediately after hip implantation. These suggested optimum clearances will also allow for low friction (i.e. friction factors of <0.2-0.07) and reasonable lubrication (dominantly mixed regime) for the likely cup deflection occurring as a result of press-fit fixation. / Smith & Nephew Orthopaedics Ltd.

The natural hip joint in healthy people has a very low friction with very little (or no) wear. It works as a dynamically loaded bearing and is subjected to about 1-2 million cycles of loading per year. The applied load is the body weight which is tripled when walking and even higher during other activities such as running and jumping. Unfortunately these joints are not always healthy due to various causes such as fractures or disease leading to severe pain which necessitates joint replacement. Currently, the orthopaedic industries are working towards developing an ideal artificial hip joint with low wear, low friction, good lubrication, better fixation/stability and biocompatibility. Many different designs and materials have been investigated with some promising new implants which can be used depending on patients¿ individual need (large or small joint), activity and age. In this work, two types of artificial hip joints were tested for friction and lubrication studies: Metal-on-Metal (MoM) Biomet hip resurfacing ReCaps with large diameters (>35-60 mm) and different diametral clearances (~ 60-350 µm), and Zirconia Toughened Alumina (ZTA) heads against carbon-fibre-reinforced poly-ether-ether ketone (CFR PEEK) cups with different diameters (>35-60 mm) and diametral clearances (60-1860 µm). Seven serum-based lubricants with different viscosities were used with and without carboxy methyl cellulose (CMC) additions as gelling agent to increase viscosity depending on the CMC content. The maximum load applied was 2000 N for the stance phase with a minimum load of 100 N for the swing phase. A Pro-Sim friction hip simulator was used to investigate the frictional torque generated between the articulating surfaces so as the friction factor can be calculated. Stribeck analysis was then employed to assess the mode of lubrication. For the metal-on-metal hip resurfacing joints, the friction factors were in the range 0.03-0.151 and those for the ZTA ceramic heads versus CFR PEEK cups were in the range 0.006-0.32. Stribeck analyses showed mainly mixed lubrication for both MoM and ZTA ceramic-on-CFR PEEK joints. The experimental results were in agreement with most of the theoretical calculations suggesting mixed lubricating regimes at low viscosities and moving on to fluid film lubrication at higher viscosities. Joints with larger-diameters, lower clearances and lower surface roughness exhibited a higher lambda ratio suggesting improved lubrication. Viscosity flow curves for the serum-based lubricants having viscosity ¿ 0.00524 Pas showed non-linear relationship between viscosity and shear rate indicating non-Newtonian flow with pseudoplastic or shear-thinning characteristic, i.e. viscosity decreased as shear rate increased up to shear rates of ~ 1000 s-1. However, at shear rates greater than 1000 s-1 Newtonian flow became dominant with almost constant viscosity, i.e. a linear relationship between shear stress and shear rate. On the other hand, viscosity flow curves for the lubricants with viscosity ¿ 0.0128 Pas showed non-Newtonian behaviour up to a shear rate of 3000 s-1 with shear-thinning characteristic. / Ministry of Higher Education, Libya

Face à la demande de plus en plus exigeante en terme de qualité et de coût de fabrication des produits manufacturés, la qualification et quantification optimal des défauts acceptables est primordial. Le tolérancement est le moyen de communication permettant de définir les variations géométriques autorisé entre les différents corps de métier intervenant au cours du cycle de fabrication du produit. Un tolérancement optimal est le juste compromis entre coût de fabrication et qualité du produit final. Le tolérancement repose sur 3 problématiques majeures: la spécification (normalisation d'un langage complet et univoque), la synthèse et l'analyse de tolérances. Nous proposons dans ce document de nouvelles méthodes d'analyse et de synthèse du tolérancement tridimensionnel. Ces méthodes se basent sur une modélisation de la géométrie à l'aide de l'outil domaine jeux et écarts développé au laboratoire. La première étape consiste à déterminer les différentes topologies composant un mécanisme tridimensionnel. Pour chacune de ces topologies est définie une méthode de résolution des problématiques de tolérancement. Au pire des cas, les conditions de respect des exigences fonctionnelles se traduisent par des conditions d'existence et d'inclusions sur les domaines. Ces équations de domaines peuvent ensuite être traduites sous forme de système d'inéquations scalaires. L'analyse statistique s'appuie sur des tirages de type Monte-Carlo. Les variables aléatoires sont les composantes de petits déplacements des torseur écarts défini à l'intérieur de leur zone de tolérance (modélisée par un domaine écarts) et les dimensions géométriques fixant l'étendue des jeux (taille du domaine jeux associé). A l'issue des simulations statistiques, il est possible d'estimer le risque de non-qualité et les jeux résiduels en fonction du tolérancement défini. Le développement d'une nouvelle représentation des domaines jeux et écarts plus adapté, permet de simplifier les calculs relatifs aux problématiques de tolérancement. Le traitement local de chaque topologie élémentaire de mécanisme permet d'effectuer le traitement global des mécanismes tridimensionnels complexes avec prise en compte des jeux. / As far as the demand in quality and cost of manufacturing increase, the optimal qualification and quantification of acceptable defects is essential. Tolerancing is the means of communication between all actors of manufacturing. An optimal tolerancing is the right compromise between manufacturing cost and quality of the final product. Tolerancing is based on three major issues: The specification (standardization of a complete and unequivocal language), synthesis and analysis of the tolerancing. We suggest in this thesis some new analysis and synthesis of the three-dimensional tolerancing. These methods are based on a geometric model define by the deviations and clearances domains developed on the laboratory. The first step consists in determining the elementary topology that composes a three-dimensional mechanism. For each kind of these topologies one resolution method is defined. In worst case, the condition of functional requirement respect is traduced by existence and inclusions conditions on the domains. Then these domains equations can be translated in inequalities system of scalar. The statistical analysis uses the Monte-Carlo simulation. The random variables are the small displacements components of the deviation torsor which is defined inside its tolerance area (model by a deviations domain) and the geometrics dimensions which set the extent of clearance (size of the clearance domain). Thanks to statistical simulation, it is possible to estimate the non-quality rate in regards to the defined tolerancing. The development of a new representation of clearances and deviations domains most suitable, allows us to simplify the calculation for tolerancing problems. The local treatment of elementary topology makes enables the global treatment of complex three-dimensional mechanisms with take into account of clearances.

Scholars and storytellers alike have deemed George MacDonald a great mythopoeic writer, an exemplar of the art. Examination of this accolade by those who first applied it to him proves it profoundly theological: for them a mythopoeic tale was a relational medium through which transformation might occur, transcending boundaries of time and space. The implications challenge much contemporary critical study of MacDonald, for they demand that his literary life and his theological life cannot be divorced if either is to be adequately assessed. Yet they prove consistent with the critical methodology MacDonald himself models and promotes. Utilizing MacDonald’s relational methodology evinces his intentional facilitating of Mythopoesis. It also reveals how oversights have impeded critical readings both of MacDonald’s writing and of his character. It evokes a redressing of MacDonald’s relationship with his Scottish cultural, theological, and familial environment – of how his writing is a response that rises out of these, rather than, as has so often been asserted, a mere reaction against them. Consequently it becomes evident that key relationships, both literary and personal, have been neglected in MacDonald scholarship – relationships that confirm MacDonald’s convictions and inform his writing, and the examination of which restores his identity as a literature scholar. Of particular relational import in this reassessment is A.J. Scott, a Scottish visionary intentionally chosen by MacDonald to mentor him in a holistic Weltanschauung. Little has been written on Scott, yet not only was he MacDonald’s prime influence in adulthood, but he forged the literary vocation that became MacDonald’s own. Previously unexamined personal and textual engagement with John Ruskin enables entirely new readings of standard MacDonald texts, as does the textual engagement with Matthew Arnold and F.D. Maurice. These close readings, informed by the established context, demonstrate MacDonald’s emergence, practice, and intent as a mythopoeic writer.