Ces travaux de recherche sont réalisés dans le cadre d’une thèse CIFRE en collaboration entre Schlumberger et le LURPA de l’ENS Cachan. Schlumberger est une entreprise de service pétrolier. Elle développe des outils de mesures fonctionnant sous des conditions sévères de température et pression élevées mais aussi des effets dynamiques tels que des accélérations produisant des chocs entre les différentes pièces.L’objectif de la thèse est de déployer de nouvelles règles de cotation, pour des assemblages hyperstatiques déformables, basées sur la méthode CLIC et les normes ISO. La déformation des pièces dépend considérablement des défauts géométriques. Nous avons donc couplé des modèles de chaînes de cotes 3D avec des modèles RdM de type poutre afin d’optimiser les tolérances. Ces modèles doivent permettre la prise en compte des jeux d’assemblage dans les liaisons, la rigidité des pièces et les différents types de contact entre les sous-ensembles des outils étudiés.Ces modèles multi-physiques ont permis de caractériser le comportement mécanique en fonction des écarts géométriques des pièces. Enfin, pour des études plus complexes, des modélisations et simulations éléments finis, sur Abaqus, ont été réalisés puis validées par une campagne expérimentale de comportement au choc. / This research is carried out within a CIFRE doctoral thesis in collaboration between Schlumberger and the LURPA of ENS Cachan. Schlumberger is an oil service company. It develops measurement tools operating under severe conditions of high temperature and pressure but also dynamic effects such as accelerations producing shocks between the different parts.The objective of the thesis is to deploy new dimensioning and tolerancing rules for deformable hyperstatic assemblies, based on the CLIC method and the ISO standards. The deformation of the parts greatly depends on the geometrical defects. We have coupled 3D dimension chains with beam models to optimize tolerances. These models must allow the taking into account of the assembly clearances between parts, their rigidity and the different types of contact between the subassemblies of the studied tools.These multi-physical models allowed to characterize the mechanical behavior as a function of the geometrical deviations of parts. Finally, for more complex studies, finite element models and simulations on Abaqus were carried out and then validated by an experimental campaign of impact behavior.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

This thesis aims to investigate digital accessibility in the making through the theoretical lens of the assemblage theory. Digital accessibility is a characteristic of digital products and services like websites that allows people with disabilities to access and use them. Although its relevance, digital accessibility is not present in many technological objects. This work intends to describe the adoption of accessibility practices in developing projects and products, focusing mainly on design activities. My leading field site was a tech company located in Stockholm, Sweden, where I observed the “accessibility project” for almost three months, from October to December 2021. During this period, I followed how the company, particularly one of its teams, reacted to new environmental factors, the challenges they faced, and how the process of incorporating these new elements was, from not having accessibility presented in the produced artefacts to incorporating accessibility as a routine. In addition, the study also counted on the participation of Brazilian design practitioners through interviews. The methods were observant participation, semi-structured interviews, and oral accounts.  The main theoretical frameworks were the assemblage theory developed by Manuel DeLanda (2016) and the theory of affordances by Jenny L. Davis (2020). I attempt to analyse the organisation and its nested structures as assemblages, and the processes of changes in their parameters, creating new territory and new code through the adoption of accessibility repertoire. I furthermore analysed the relations between the affordances of technological objects produced by the company’s assemblage, as well as the affordance of accessibility frameworks.

No description available.

No description available.

Streams are integrative systems spanning multiple spatial and temporal scales. Stream researchers, land-use managers, and policy decision makers must consider the downstream displacement of streams when approaching questions about stream ecosystems. The study of how anthropogenic land-use influences streams demands an ecosystem perspective, and this dissertation is an example of applying large scale analyses of stream reach responses, and linking the activity of humans in the landscape to stream structure and function. I investigate whether rural development and agriculture land-cover types influence abiotic and biotic stream responses. I establish a method for considering land-cover as an independent variable at multiple scales throughout a streams' watershed using hydraulic modeling. The travel time required for water to drain from the watershed to a stream reach provided a continuous index to delimit watershed sub portions along a spatial continuum. Within travel time zones (TTZs), I consider land-use at increasingly larger scales relative to a stream reach within which biotic responses are typically measured. By partitioning land-cover in TTZs, I was able to determine the spatial scale at which land-cover was most likely to influence in-stream responses. I quantified a suite of physical and biotic responses typical to the aquatic ecology literature, and found that streams did not respond much to rural development. Rural development influenced suspended and depositional sediments, and likely altered watershed hydrology though I was unable to find significant evidence supporting a hydrologic effect. Subtle differences in assemblages suggest that differences in sediment dynamics influenced macroinvertebrates and fish. Using the Land Cover Cascade (LCC) design, I link the influence of land-cover to biotic responses through a suite of multivariate models, focusing on sediment dynamics in an attempt to capture the subtle influence of hydrology and sediment dynamics. My dissertation provides future researchers with improved methods for considering land-cover as an independent variable, as well as introduces multivariate models that link land-cover to sediment dynamics and biota. My dissertation will assist future research projects in identifying specific mechanisms associated with stream responses to disturbance. / Ph. D.

Four intervals of Middle Pennsylvanian marine strata in the Breathitt Formation of eastern Kentucky, the Elkins Fork, Kendrick, Magoffin, and Stoney Fork, were measured, sampled for fossils, and described. Each marine interval was shown to be the product of a single episode of transgression and regression that led to the establishment of a variety of marine habitats in the central Appalachian basin. These habitats included marginal marine, nearshore normal marine, nearshore stressed, offshore normal marine, and offshore dysaerobic environments. Fossil collections were made and species abundance distributions were obtained for each paleontological sample. Multivariate statistical analyses such as cluster analysis and principle components analysis were used to classify fossil assemblages sampled into a variety of paleocommunity types, each associated with a particular lithological facies. Paleocommunity types that were found to occur in more than one of the four marine intervals were resampled at selected localities, with replicate samples taken at each locality. These additional samples were used to test for the presence of the same statistically defmed paleocommunity at different localities within the same marine units and to test for the recurrence of statistically defmed paleocommunities between marine units. Results of the analyses suggest that recurrence of similar fossil assemblages (paleocommunity types) is common in the Breathitt marine units whenever there is recurrence of comparable marine facies. However, recurrence of the same statistically defined paleocommunity is rare, with significant variation in the abundances of member species appearing each time a particular paleocommunity type recurs. This suggests that the recurrence of distinct fossil assemblages over intervals of geologic time can be explained by the repeated reinvasion of suitable habitats by the individual members of a persistent species pool, without recourse to ecological mechanisms needed for preserving or perpetuating particular community structures. / Ph. D.

<p>This dataset contains results of a palynological study completed by Dr. Robert L. Raven from the IRF Group Inc in December 29, 2018</p> <p><br></p> <p>Palynological analysis was performed on siltstone samples that were collected from 4 outcrops of cenozoic strata from the study area of Chapter 3 in the eastern Alaska Range. This file includes the results of that study and detail about he present pollen assemblages as well as images</p> <p><br></p> <p>Jeffrey Benowitz contracted this work</p>

L’équilibrage statique d’un manipulateur robotique apporte plusieurs avantages. Ceux-ci comprennent notamment : une diminution des efforts d’actionnement dans un contexte statique, l’augmentation de la charge utile, une commande simplifiée et un robot plus sécuritaire dans un contexte d’interaction avec un humain. Incorporer une telle technologie à un manipulateur existant est donc souhaitable. Par contre, les techniques actuelles ne permettent pas l’intégration facile d’une compensation statique. Pour répondre à cette problématique, une nouvelle technique d’équilibrage est développée dans ce mémoire. Le concept présenté se base sur l’interaction entre des champs magnétiques pour produire un couple. En utilisant des cylindres d’Halbach imbriqués, un couple sinusoïdal théorique correspondant parfaitement à une charge gravitationnelle est obtenu. Cette technique est générale et peut être adaptée à différents contextes. Dans ce mémoire, la géométrie est optimisée dans le but de maximiser le couple produit et la compacité du prototype. Les aimants résultants sont assez complexes. Cela dit, dans un concept pratique, ils peuvent être segmentés afin de simplifier leur fabrication et leur intégration. Afin de démontrer qu’une compensation statique magnétique est une solution viable, un prototype est intégré à un robot industriel existant. Les résultats obtenus prouvent que le module de compensation statique développé réduit significativement le couple d’actionnement requis et ils justifient la poursuite des travaux dans ce domaine.

Le but de cette thèse fut d'optimiser le procédé d'aboutage par entures multiples du bois d'épinette noire. L'approche développée propose une méthodologie basée sur l'optimisation des paramètres de procédé dans les différentes étapes de l'aboutage soit l'effet de la forme et géométrie des joints, l'effet de la pression et temps de durcissement de l'adhésif, l'effet de la température et de la teneur en humidité du bois et les effets de la vitesse de coupe et de l'avance par couteau. Les variables étudiées ont été choisies suite à un sondage effectué dans cinq usines de bois abouté du Québec. La méthodologie adoptée a considéré des essais préliminaires et des essais d'optimisation du procédé. La thèse fournit de l'information sur des paramètres optimisés de l'aboutage du bois de l'épinette noire, inconnus jusqu'à aujourd'hui. / In Eastern Canada, black spruce (Picea mariana (Mill.) B.S.P.) has recently been introduced to finger-joined wood products. While there is a growing economic importance of the species in such applications, little information is available on the manufacturing parameters that influence the finger-jointing process for this species. The purpose of this work was to optimize the finger-jointing process of black spruce wood. Various parameters associated with the finger-jointing process were evaluated. Those included the following: finger-joint configurations, curing time and end-pressure, wood temperature and moisture content and wood machining parameters. Isocyanate adhesive was used for all types of evaluations. Results from configurations evaluation indicated that the feather configuration performs better than male-female and reverse profiles, especially for horizontal structural joints. The effect of moisture content on the mechanical performance of joined black spruce wood was not very conclusive. However, the experiment on wood temperature showed the lowest tensile strength at -5°C. Results on the effect of pressure and curing time showed that curing time and end-pressure have a statistically significant influence on the performance of structural finger-joints. Analysis indicated that finger-joined black spruce has the best performance at an end-pressure of 3.43 MPa (498 psi). For wood machining parameters, results indicated that suitable finger-jointing in black spruce could be achieved within a range of 1676 m/min (5498 feet/min) and 2932 m/min (9621 feet/min) of cutting speed and between 0.86 mm and 1.14 mm of chip-load. The microscopical analysis of damaged cells confirmed the effect of cutting speed on the finger-jointing process. In general, depth of damage was more severe as cutting speed increased. Results obtained in this research could help mills to optimize the process and improve the mechanical performance of finger-joined black spruce product.