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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

The dynamics of category conjunctions

Hutter, R.R.C., Crisp, R.J., Humphreys, G.W., Waters, Gillian M., Moffitt, G. 28 August 2009 (has links)
no / In three experiments we investigated the dynamics of impression formation when perceivers encounter unsurprising (e.g. male mechanic) versus surprising (e.g. female mechanic) social category conjunctions. In Experiment 1, participants took longer to form an impression of targets described using a surprising versus an unsurprising conjunction of categorizations. In Experiment 2, we investigated the stages during which impressions of category conjunctions are formed. While unsurprising category combinations were characterized with reference to ‘constituent’ stereotypic traits, surprising combinations were characterized initially by stereotypic traits but later by ‘emergent’ impressions. In Experiment 3, we investigated motivational states that drive the dynamics of category conjunction. We found that higher Personal Need for Structure (PNS) predicted the use of more emergent and fewer constituent attributes in the impressions formed of surprising combinations. Across all three experiments, more ‘causal attributes’ were used in descriptions of the surprising combination. We discuss the implications of these findings for developing a model of the dynamics and composition of social category conjunctions.
52

Coffrer la complexité : comment matérialiser les formes non-standards en béton par l'impression 3D

Michel, Antoine 26 October 2023 (has links)
Titre de l'écran-titre (visionné le 25 octobre 2023) / Ce mémoire est l'aboutissement d'une recherche-création de deux ans sur la conception et la fabrication numérique appliquées à la construction en béton. Les six chapitres qu'il comprend traitent de l'état actuel des méthodes utilisées pour la mise en place de formes complexes en béton, du potentiel des nouvelles méthodes émergentes et finalement, de l'impact potentiel de ces méthodes sur les processus de conception et de fabrication. La recherche-création était une méthodologie de recherche. Elle permettait de concevoir des éléments complexes à mettre en place pour pousser au maximum les limites des méthodes testées et soulever les enjeux architecturaux et constructifs propres à chacune. L'aller-retour créatif entre la conception et la technique permet de valider ou d'invalider de manière directe les possibilités offertes par la fabrication additive pour le coffrage de formes complexes. Ces méthodes incluent -- mais ne se limitent pas à -- l'impression 3D flexible, l'impression 3D soluble et l'impression 3D nylon. Leurs forces et faiblesses sont discutées dans le mémoire, et des recommandations sur les situations optimales à l'utilisation de chacune se retrouvent à la fin de leurs sections respectives. Finalement, on retrouve dans le mémoire des expérimentations, observations et réflexions sur la trace de l'outil et l'augmentation d'échelle. Ces deux sections permettent de comprendre l'ensemble du potentiel architectural concret suggéré par ces nouveaux modes de fabrication. Parfois limitées par les moyens accessibles dans le cadre de cette recherche, des explorations sur les différentes manières de mettre en place des éléments complexe en béton à grande échelle viennent complémenter la recherche théorique à cet égard. La collaboration avec les chercheurs en ingénierie du CRIB de la faculté de génie de l'Université Laval a d'ailleurs été essentielle à la validation de certains de ces éléments théoriques. Finalement, l'objctif de cette recherche était de rassembler un maximum de connaissances théoriques et pratique sur les manières de mettre en place une architecture en béton complexe afin de mettre à jour un paysage technologique en constante évolution. / This thesis is the culmination of a two-year research-creation project on digital design and fabrication applied to concrete construction. Its six chapters address the current state of methods used for creating complex concrete forms, the potential of emerging methods, and ultimately, the potential impact of these methods on the design and fabrication processes. Research-creation was the chosen research methodology, allowing for the design of complex elements to push the limits of the tested methods and raise architectural and construction issues at each step. The iterative process between design and technique directly validates or invalidates the possibilities offered by additive manufacturing for complex formwork. These methods include -- but are not limited to -- flexible 3D printing, soluble 3D printing, and nylon 3D printing. Their strengths and weaknesses are discussed in the thesis, and recommendations for their optimal use in specific situations are provided at the end of their respective sections. Additionally, the thesis presents experiments, observations, and reflections on the tool's trace and the scaling of these processes. These two sections help comprehend the full architectural potential suggested by these new fabrication methods. While limited by the available resources within the scope of this research, explorations on different approaches to implementing large-scale complex concrete elements complement the theoretical research in this regard. The collaboration with engineering researchers from the CRIB at the Faculty of Engineering of Université Laval was essential in validating some of the more theoretical aspects. Ultimately, the objective of this research was to gather a maximum amount of theoretical and practical knowledge in order to update a constantly evolving technological landscape regarding the fabrication of complex concrete architecture.
53

Développement de verres phosphates à basse température de transition vitreuse pour l'impression 3D et ses applications

Kaser, Simon 26 May 2023 (has links)
Thèse en cotutelle : « Université Laval, Québec, Canada et Université de Bordeaux, Talence (France) » / Thèse en cotutelle : « Université Laval, Québec, Canada et Université de Bordeaux, Talence (France) » / La fabrication additive, ou impression 3D, regroupe un ensemble de procédés de mise en forme des matériaux par ajout de matière, en opposition avec les méthodes "traditionnelles" soustractives, comme par exemple l'usinage. De nombreux procédés de fabrication additive existent, et divers matériaux sont exploitables par impression 3D, comme des métaux, des polymères ou des céramiques. En revanche, très peu de solutions ont pour l'instant été proposées pour l'impression de verre, principalement à cause des hautes températures de travail nécessaires. L'objectif de cette thèse est donc de réaliser la fabrication additive de verres phosphates, avantageux pour leurs températures de travail plus faibles et recherchés pour leurs applications dans l'optique ou les biomatériaux. Cela passe par le développement de compositions de verres phosphates adaptées avec de basses températures de transition vitreuse. Dans un premier temps, des verres de composition (50 - x) P₂O₅ - 25 Na₂O - 25 K₂O - x M₂O₃ (%ₘₒₗ), avec M = Al ou Ga et x entre 0 et 10 %ₘₒₗ, ont été étudiés. La composition la plus optimale a ensuite été imprimée via un procédé de dépôt de fil fondu grâce à une imprimante commerciale pour polymères modifiée. Afin d'obtenir des objets imprimés en verre qui sont transparents, il a fallu optimiser les paramètres d'impression pour éliminer les potentiels défauts. Des caractérisations sur les pièces imprimées en verre ont permis d'estimer que la porosité résiduelle était inférieure à 0,02 %. Grâce à ce procédé de fabrication additive de verres phosphates, l'impression de composants optiques à géométries complexes et aux propriétés uniques est envisageable. Un deuxième axe d'étude concerne l'élaboration de verres phosphates hydratés transparents, dont la température de transition vitreuse est inférieure à 100 °C et pouvant être synthétisés à seulement 300 °C. Ces matériaux innovants ont été caractérisés par spectroscopies Raman, infrarouge et RMN afin d'en déterminer la structure. Des groupements -OH sont observés au sein du réseau phosphate, agissant comme des modificateurs du réseau vitreux et sont donc à l'origine des modifications des propriétés du verre. En ajoutant de l'oxyde de zinc à la composition, il est possible d'améliorer la résistance à la dissolution des verres phosphates hydratés tout en maintenant leur transparence et leur basse température de transition vitreuse. Ces nouveaux matériaux ouvrent la voie à des nouvelles voies de fonctionnalisation, dont certaines ont été étudiées avec la réalisation de fibres multimatériaux verre oxyde-polymère et l'inclusion de nanoparticules de trioxyde de tungstène. / Additive manufacturing, also known as 3D printing, refers to a set of manufacturing techniques by adding matter, as opposed to the more 'traditional' subtractive methods, such as machining. There are a lot of very different additive manufacturing processes, as well as a diversity of printable materials, including metals, ceramics and polymers. However, very few solutions have been developed so far for the printing of glass. The main obstacles are the very high processing temperatures required. The main objective of this thesis is to enable the additive manufacturing of phosphate glasses. These glasses are advantageous for their lower working temperatures and are also known for their applications in optics and biomaterials. To that purpose, convenient phosphate glass compositions with low glass transition temperatures were developed. The first system studied was (50 - x) P₂O₅ - 25 Na₂O - 25 K₂O - x M₂O₃ (%ₘₒₗ), with M = Al ou Ga and x between 0 and 10 %ₘₒₗ. The most ideal composition studied in the system was then successfully printed following a fused deposition modeling process, using a modified commercial polymer 3D printer. To obtain printed glass objects that are transparent, printing parameters were finely tuned to avoid potential defects. The residual porosity of printed glass objects is estimated to be lower than 0.02 %. Being able to print phosphate glasses with this process enables the fabrication of optical parts with complex geometries and unique properties. Transparent hydrated phosphate glasses were also studied. These materials exhibit a glass transition temperature below 100 °C and could be synthetized at temperatures as low as 300 °C. The structure of these new materials was then investigated, using Raman, infrared and NMR spectroscopies. -OH groups were found within the phosphate network, where they act as network modifiers, causing the modification of the glass' properties. By adding zinc oxide to the glass composition, it is possible to make the hydrated phosphate glasses more resistant to dissolution while keeping their transparency and their low glass transition temperature. These materials enable new functionalization possibilities, some of which were studied. For instance, glass-polymer composite fibers were made, and tungsten trioxide functional nanoparticles were integrated in a hydrated phosphate glass matrix.
54

Linear expansion of dental stone after its final set and beyond two hours

Cid Galano, Marcos. January 2003 (has links)
Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains viii, 43 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 41-42).
55

Accuracy of addition silicone impression materials as a function of technic a thesis submitted in partial fulfillment ... in dental materials /

Johnson, Glen H. January 1983 (has links)
Thesis (M.S.)--University of Michigan, 1983.
56

Accuracy of addition silicone impression materials as a function of technic a thesis submitted in partial fulfillment ... in dental materials /

Johnson, Glen H. January 1983 (has links)
Thesis (M.S.)--University of Michigan, 1983.
57

Surface conditions of stone in contact with alginate and rubber base impressions a thesis prepared as partial fulfillment ... in prosthetic dentistry ... /

Cain, Martin J. January 1957 (has links)
Thesis (M.S.)--University of Michigan, 1957.
58

Greenwashing in CSR reports - A case study of two entities

Dzafic, Jasmin, Petersson, Angelica January 2016 (has links)
No description available.
59

News Media Coverage of Corporate Tax Avoidance and Corporate Tax Reporting

Lee, Soojin 08 May 2015 (has links) (PDF)
Drawing upon media agenda-setting theory and previous studies in organizational impression management, this paper empirically investigates the influence of tax avoidance news on corporate tax reporting. This study is based on the pronounced discontinuity in the amount of news articles related to tax avoidance in the United Kingdom over two periods (2010-2011 and 2012-2013). A difference-in-differences design is employed in order to enable a comparison of the media effects on those firms that have been reported in tax avoidance news versus those without media attention. Using a sample of annual reports of UK FTSE 100 companies across the period 2010 to 2013, I test the impact of tax avoidance news on quality and quantity of tax disclosure. The results suggest that the recent increase in media attention on tax avoidance does not stimulate firms to improve the quality and the quantity of tax disclosure in their corporate reporting. Rather, firms can be discouraged from discussing the most relevant tax items in their reporting, as shown in the case of financial firms which were the subject of the largest amount of tax avoidance news. (author's abstract) / Series: WU International Taxation Research Paper Series
60

Impression formation on social network sites during university transition

Doodson, James January 2017 (has links)
Most research investigating impression formation during early stages of a relationship on social network sites adopts unrealistic, ecologically invalid social scenarios. This thesis used an ecologically valid social scenario to improve understanding of impression formation during the early stages of a relationship on social network sites. Three studies investigated how students get to know each other on social network sites in the weeks before starting university. A focus group study, a questionnaire study and an experiment demonstrated that incoming undergraduate students form impressions about groups of people (e.g. a group of housemates) and specific individuals (e.g. a housemate) during university transition. The studies highlighted that it is too simplistic to suggest that impression formation about a group of people is different from impression formation about a specific individual. Instead, the coherence of the social target, the nature of the affiliation with that social target, and the strategies used to get to know that social target on social network sites influence how confident students are in their impressions of each other during university transition. Explanations are proposed that, if substantiated, would require expansion of the Hamilton and Sherman’s and cues-filtered in theories of impression formation. The studies highlighted that impression formation and the influence of those three factors can partially explain the intensity of students’ worries about the academic and social aspects of their future university experience. The findings are practically applied as guidance for university and pastoral support services and further research is proposed to test the tentative explanations.

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