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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.
71

Micromoulding: extreme process monitoring and in-line product assessment.

Whiteside, Benjamin R., Howell, Ken B., Martyn, Michael T., Spares, Robert 08 June 2009 (has links)
No / Advances in micromoulding technology are now allowing mass production of complex, three-dimensional functional products having sub-milligram masses and carefully tailored surface finishes. In order to create a viable manufacturing process for these components, accurate process monitoring and product evaluation are essential in order to highlight process problems and production of substandard parts. The present study describes work implementing a suite of sensors on a commercial micromoulding machine for detailed process interrogation. Evaluation of demoulded products is performed with a single camera based system combined with custom software to allow for three-dimensional characterisation of products during the process.
72

Méthodes de réduction et de propagation d'incertitudes : application à un modèle de chimie-transport pour la modélisation et la simulation des impacts

Boutahar, Jaouad 30 September 2004 (has links) (PDF)
Dans une modélisation intégrée des impacts, l'objectif est de tester plusieurs scénarios d'entrées de modèle et/ ou d'identifier l'effet de l'incertitude des entrées sur les sorties de modèle. Dans les deux cas, un grand nombre de simulations de modèle sont nécessaires. Cela reste bien évidemment infaisable avec un modèle de Chimie-Transport à cause du temps CPU demandé. Pour surmonter cette difficulté, deux approches ont été étudiées dans cette thèse : La première consiste à construire un modèle réduit. Deux techniques ont été utilisées : la première est la méthode POD (Proper Orthogonal Decomposition) liée au comportement statistique du système. La seconde méthode est une méthode efficace de prétabulation fondée sur la troncature d'un développement multivariables de la relation Entrées/ sorties associé au modèle.<br />La seconde est relative à la réduction du nombre de simulations demandé par la méthode Monte-Carlo classique de propagation d'incertitude. La technique utilisée ici est basée sur une représentation d'une sortie de modèle incertaine comme un développement de polynômes orthonormaux de variables d'entrées. Un autre point clé dans la modélisation intégrée d'impacts est de développer des stratégies de réduction des émissions en calculant des matrices de transfert sur plusieurs années de simulation. Une méthode efficace de calcul de ces matrices a été ainsi développée, notamment en définissant des scénarios "chimiquement" représentatifs.<br />L'ensemble de ces méthodes a été appliqué au modèle POLAIR3D, modèle de Chimie-Transport développé dans le cadre de cette thèse.
73

Modeling in-situ vapor extraction during flow boiling in microscale channel

Salakij, Saran 25 March 2014 (has links)
In-situ vapor extraction is performed by applying a pressure differential across a hydrophobic porous membrane that forms a wall of the channel as a means of reducing the local quality of flow boiling within the channel. As the local quality is reduced, the heat transfer capability can be improve while large pressure drops and flow instability can be mitigated. The present study investigates the potential of vapor extraction, by examining the characteristics and mechanisms of extraction. The physics based models for transition among extraction regimes are developed which can be used as a basis for a regime-based vapor extraction rate model. The effects of vapor extraction on flow boiling in a microscale fractal-like branching network and diverging channels are studied by using a one-dimensional numerical model based on conservation of mass and energy, along with heat transfer and pressure drop correlations. The results show the improvement in reduced pressure drop and enhanced flow stability, and show the potential of heat transfer enhancement. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from March 25, 2013 - March 25, 2014
74

Implementace Filozofie pro děti do oddělení školní družiny / Implementation of Philosophy for Children in an after-school club

DŘEVOVÁ, Šárka January 2018 (has links)
This thesis describes the proces of implementation of selected elements of Philosophy for Children in the activities of an after-school club. Philosophy for Children and the school club are presented in the theoretical part. The case study describes twenty Philosophy for Children sessions carried out in the morning and afternoon school club programme. Furthermore, factors influencing the programme that have been encounte-red during the philosophical sessions are discussed.
75

Studie řešení protipovodňové ochrany části obce Janová na levém břehu Vsetínské Bečvy / Flood protection study of Janová urban neighbourhood situated on the left side of Vsetínská Bečva river

Böhm, Petr January 2012 (has links)
Diploma´s thesis solve flood protection study of Janova (region Vsetín). Model of flow was created based on geometry of the watercourse and hydrological data of Vsetinska Becva on the municipality. Model of flow was created using HEC-RAS 4.1. Calculation results of centenarian maximum peak discharge were base for design measures, which were the necessary for improvement flood protection of area.
76

Phase-field modeling of brittle fracture along the thickness direction of plates and shells

Ambati, Marreddy, Heinzmann, Jonas, Seiler, Martha, Kästner, Markus 22 January 2024 (has links)
The prediction of fracture in thin-walled structures is decisive for a wide range of applications. Modeling methods such as the phase-field method usually consider cracks to be constant over the thickness which, especially in load cases involving bending, is an imperfect approximation. In this contribution, fracture phenomena along the thickness direction of structural elements (plates or shells) are addressed with a phase-field modeling approach. For this purpose, a new, so called “mixed-dimensional” model is introduced, which combines structural elements representing the displacement field in the two-dimensional shell midsurface with continuum elements describing a crack phase-field in the three-dimensional solid space. The proposed model uses two separate finite element discretizations, where the transfer of variables between the coupled twoand three-dimensional fields is performed at the integration points which in turn need to have corresponding geometric locations. The governing equations of the proposed mixed-dimensional model are deduced in a consistent manner from a total energy functional with them also being compared to existing standard models. The resulting model has the advantage of a reduced computational effort due to the structural elements while still being able to accurately model arbitrary through-thickness crack evolutions as well as partly along the thickness broken shells due to the continuum elements. Amongst others, the higher accuracy aswell as the numerical efficiency of the proposed model are tested and validated by comparing simulation results of the new model to those obtained by standard models using numerous representative examples.
77

Разработка методических рекомендаций для проверки цифровой информационной модели в ГАУ СО «Управление государственной экспертизы» : магистерская диссертация / Development of methodological recommendations for checking the digital information model in the State Autonomous Institution SO “Office of State Expertise”

Литуева, Ю. Д., Litueva, Yu. D. January 2024 (has links)
Цель работы − разработка методических рекомендаций по проведению проверки цифровой информационной модели раздела АР, КР и ПБ формата ifc для ГАУ СО «Управление государственной экспертизы». Для достижения поставленной цели были поставлены следующие задачи: построить модель и наполнить ее требуемой информацией, используя возможности ПО Revit; выделить основные принципы подготовки ЦИМ к экспертизе; проверить информацию из модели в формате IFC с помощью ПО Tangl Control. Сформировать проверки валидации и верификации; сформировать методические рекомендации, описывающие проведение проверки ЦИМ АР и КР в ПО Tangl Control экспертизой. / The purpose of the work is to develop methodological recommendations for checking the digital information model of the section AR, KR and PB in the ifc format for the State Autonomous Institution SO “Office of State Expertise”. To achieve this goal, the following tasks were set: build a model and fill it with the required information using the capabilities of Revit software; highlight the basic principles of preparing CIM for examination; check the information from the model in IFC format using Tangl Control software. Create validation and verification checks; create methodological recommendations describing the verification of CIM AR and KR in Tangl Control software by expert examination.

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