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Совершенствование технологического процесса обработки корпусной детали высокой сложности «Корпус» с элементами исследования средств технологического обеспечения операций в условиях автоматизированного производства : магистерская диссертация / Improving the technological process of processing a hull part of high complexity “Housing” with elements of research of means of technological support of operations in automated production conditionsПанасюк, А. Г., Panasyuk, A. G. January 2020 (has links)
The master's thesis consists of three parts: technological, design and research. In the technological part, the improvement of the technological process for the manufacture of basic parts in modern conditions using automated production is considered. In the design part, the development of a mechanized mounting and clamping device for a vertically milling operation and a control and measuring device for a control operation are carried out. In the research part, optimization of cutting conditions for milling a flat surface of the body with milling cutters of various diameters of domestic and foreign manufacturers is given. This part contains a comparison of the milling resistance, determination of the number of workpieces and a comparison of the cost of cutting tools of two manufacturers. The necessary set of design and technological documentation has been formed. / Магистерская диссертация состоит из трех частей: технологической, конструкторской и научно-исследовательской. В технологической части рассматривается совершенствование технологического процесса на изготовление корпусной детали в современных условиях с использованием автоматизированного производства. В конструкторской части производится разработка механизированного установочно-зажимного приспособления на вертикально-фрезерную операцию и контрольно-измерительного приспособления на контрольную операцию. В научно-исследовательской части приведена оптимизация режимов резания для фрезерования плоской поверхности корпуса фрезами различного диаметра отечественного и зарубежного производителей. Данная часть содержит сравнение стойкости фрез, определение количества обрабатываемых деталей и сравнение стоимости режущих инструментов двух производителей. Сформирован необходимый комплект конструкторской и технологической документации.
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Dimensional Analysis of Electromagnetic Particle Transport in a Fluid Flow under an Electromagnetic Field inspired by Biomedical ApplicationsWonseok Heo (13171947) 29 July 2022 (has links)
<p>This study, motivated by biomedical applications such as drug delivery and adsorption, is aimed at describing magneto- and dielectro-phoretic systems via dimensional analysis to quantitatively assess the relative contribution of hydrodynamics, electromagnetism, and particle dynamics. Magnetophoresis and dielectrophoresis, phenomena of magnetic and dielectric particle transports, respectively, have been used in various applications requiring selective collecting or separating magnetic particles, especially in microfluidic systems.</p>
<p>A multiphysics computational model for a magnetophoretic system was developed to assess magnetophoretic characteristics. The magnetically induced mobility of the magnetic particles was simulated for a range of parameters relevant in biomedical applications, including the particle and fluid properties, fluid velocity, and geometries of the particle, flow channel, and magnet. With the help of dimensional analysis, dimensionless numbers were introduced to reduce the number of parameters characterizing the transport of the particles suspended in an electrically non-conducting fluid exposed to an external magnetic field. As a result, 14 relevant variables determining the particle capture were reduced to only 3 dimensionless numbers describing the magnetophoretic system. The results from multiphysics models supported this analysis, suggesting a scaling law. The functional relationship among the dimensionless numbers resulted in prediction curves to assess the particle capture. The performance of the magnetophoretic system predicted with the dimensional analysis was verified in comparison with the available experimental data. In addition, the dimensionless numbers introduced here were compared with established numbers in magnetohydrodynamics (MHD).</p>
<p>These theoretical and parametrical analyses of the magnetophoretic system were applied to the novel magnetic filter proposed to capture the drug-loaded small magnetic particles (MPs) from the bloodstream during the Intra-Arterial Chemotherapy (IAC). The IAC is a preferred treatment for unresectable hepatocellular carcinoma (HCC), the primary liver cancer. In the IAC procedure, chemotherapeutic agents, e.g. doxorubicin (Dox), are administered via a catheter placed in an artery supplying the tumor. The effectiveness of the IAC, however, is limited due to the passage of excessive chemotherapy agents to the blood circulation after their effect on the tumor, causing systemic toxicity. To remove the excessive drugs, the endovascular filtration devices have been developed. The proposed magnetic filtration device could be deployed from a catheter placed in the hepatic vein or inferior vena cava (IVC) to remove the excessive Dox from the bloodstream. The Ferumoxytol approved by the FDA is one of the types of the ultrasmall superparamagnetic iron oxide (USPIO) particles. The excessive Dox-coated USPIO can be filtered by a magnetic catheter-based device generating an external magnetic field. The filter utilizing magnetic fields is a promising method for therapeutic applications since an influence of magnetic field reaches comparatively wide ranges and magnetic fields do not affect biological tissues. To optimize the design, efficacy, and performance of the proposed magnetic filtration device, numerical models were developed based on the proposed dimensionless numbers characterizing drug transport and binding. Drug adsorption can be optimized by modifying magnetic field distribution and device configuration. To enhance the filtering up to 70-80 % of the excessive drug, multi-stage filters were developed by optimizing magnet configuration and flow patterns. By decreasing the concentration of toxins in the cardiovascular system, the drug dosage can be increased while reducing side effects, thus improving the effectiveness of the IAC treatment.</p>
<p>In addition, new dimensionless numbers for dielectrophoresis analogous to magnetophoresis were introduced for a range of applications. The proposed dimensionless numbers for dielectrophoresis were evaluated for several conditions and compared with the previously established numbers in electrohydrodynamics (EHD). </p>
<p>This study provides a promising framework for analyzing and predicting performance of various magneto- and dielectro-phoretic systems for a range of applications, particularly in biomedicine such as –drug filtering, targeted drug delivery, or small particle separation–, thus providing a reliable methodology for predicting particle manipulation. </p>
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Situations d’intimidation sous-jacentes à la pratique infirmière au Québec : coconstruction théoriqueDurocher, Hélène 02 1900 (has links)
L’intimidation entre infirmières constitue une menace pour la santé et le bien-être de ces professionnelles de la santé et pour la qualité des soins. En dépit des efforts déployés jusqu’à présent pour lutter contre ce fléau, il existe peu d’actions efficaces pour le contrer. Or, pour que les acteurs concernés puissent s’engager à intervenir, il est essentiel d’appréhender les réalités entourant ce type d’intimidation et de renforcer l’assise théorique actuelle qui fait défaut dans les écrits, notamment en sciences infirmières. Cette étude vise à coconstruire une théorie des situations d’intimidation entre infirmières, selon le point de vue d’infirmières et d’infirmiers québécois les ayant vécues à titre de cibles ou de témoins dans le cadre de leur pratique.
Cette étude s’inscrit dans le paradigme constructiviste social/constructionniste social inspiré de la pensée de Charmaz (2014) et est guidée par la perspective théorique interactionniste critique (Burbank et Martins, 2010; Martins et Burbank, 2011; Sandström et Fine, 2003). Elle prend appui sur une approche méthodologique interprétative/qualitative exploratoire qui résulte de la convergence entre la théorisation ancrée constructiviste (Charmaz, 2014), l’analyse situationnelle (Clarke et al., 2015) et l’analyse dimensionnelle (Schatzman, 1991; Schatzman et Strauss, 1973). Cinquante-deux infirmières et infirmiers répartis dans dix régions du Québec ont pris part à cette étude. Ils exerçaient différentes fonctions dans divers secteurs d’activité. Les données ont été recueillies à l’aide d’échanges informels, d’entretiens individuels et dyadiques de type conversationnel, de e-témoignages, de matériel invoqué et d’un questionnaire sociodémographique autoadministré. Le processus itératif de la collecte et l’analyse des données a permis de porter attention aux processus, aux actions, aux interactions sociales, aux structures sociopolitiques, aux contextes et aux discours sociaux dominants.
Les résultats proposent une coconstruction théorique qui témoigne d’une conception multidimensionnelle des situations d’intimidation sous-jacentes à la pratique infirmière. Cette coconstruction théorique révèle la nature plurielle et évolutive de telles situations. Elle met en évidence quatre regroupements dimensionnels interdépendants : 1) des conditions situationnelles (antécédents) qui s’articulent autour des dimensions : contextes sociaux et conditions micro et macrosociologiques, 2) un processus de création des situations d’intimidation qui se déroule en cinq phases. Les trois premières phases a) la situation initiale : ç’a commencé comme ça ! b) l’ancrage : ça continue ! et c) l’impasse : être dedans ! s’inscrivent dans la tolérance et le statu quo, alors que les deux dernières phases d) la mobilisation de ressources de soutien et e) la rupture sont ancrées dans une perspective d’action vers le changement, 3) des conséquences sur l’état de santé et de bien-être personnel et professionnel de l’infirmière intimidée ou témoin et sur la qualité des soins et, 4) un continuum espace-temps inhérent aux situations d’intimidation. La coconstruction théorique dévoile le cycle de vie des situations d’intimidation sous-jacentes à la pratique infirmière permettant ainsi de mieux comprendre comment et pourquoi ce type de situations naissent, se produisent, se transforment et se terminent.
Les résultats de cette étude révèlent, entre autres, des moments propices aux transitions professionnelles pouvant marquer le début de situations d’intimidation, la formation d’alliances informelles (en cliques), des divisions internes au sein de la profession, l’adaptation de la pratique de l’infirmière intimidée à son environnement de travail toxique et la dénonciation de son vécu d’intimidation prenant appui sur des principes semblables à l’advocacy et à la parrhèsia. Des conséquences sur la santé, le bien-être, la vie sociale, la dignité, l’identité professionnelle et le parcours de carrière de l’infirmière intimidée ou témoin sont constatées.
Cette étude doctorale a permis d’appréhender de manière novatrice un sujet sensible et tacite comme des situations d’intimidation. Elle propose des recommandations pour les différents champs de la pratique infirmière et fournit des leviers de réflexion et d’action permettant de promouvoir des environnements de travail sains. Or, tout en contribuant au développement des connaissances en sciences infirmières, la présente étude offre un cadre de compréhension des situations d’intimidation sous-jacentes à la pratique infirmière. Les pistes de réflexions et d’actions proposées pourraient permettre des avancées dans la lutte contre cette forme de violence qui sévit dans certaines organisations de santé et, potentiellement, dans d’autres domaines du monde du travail. / Bullying among nurses poses a threat to the health and well-being of these health professionals and to the quality of care. Despite the efforts made to date to combat this scourge, there are few effective actions to counter it. However, so that the actors concerned can commit to intervening, it is essential to understand the realities surrounding the bullying situations underlying nursing practice and to strengthen the current theoretical basis, which is lacking in the literature, particularly in nursing sciences. This study aims to co-construct a theory of bullying situations between nurses, according to the point of view of Quebec nurses who have experienced them as targets or witnesses in the context of their practice.
This study is part of the social constructivist/social constructionist paradigm inspired by the thought of Charmaz (2014) and is guided by the critical interactionist theoretical perspective (Burbank et Martins, 2010; Martins et Burbank, 2011; Sandström et Fine, 2003). It is based on an exploratory interpretive/qualitative methodological approach which results from the convergence between constructivist grounded theory (Charmaz, 2014), situational analysis (Clarke et al., 2015) and dimensional analysis (Schatzman, 1991; Schatzman et Strauss, 1973). Fifty-two nurses spread across ten regions of Quebec took part in this study. They performed different functions in various sectors of activity. Data were collected using informal exchanges, individual and dyadic conversational interviews, e-testimonies, invoked material and a self-administered sociodemographic questionnaire. The iterative process of data collection and analysis allowed attention to processes, actions, social interactions, socio-political structures, contexts, and dominant discourses.
The results propose a theoretical co-construction which demonstrates a multidimensional conception of bullying situations underlying nursing practice. This theoretical co-construction reveals the plural and evolving nature of such situations. It highlights four interdependent dimensional groupings: 1) situational conditions (antecedents) which revolve around the dimensions: social contexts and micro and macrosociological conditions, 2) a process of creating bullying situations which takes place in five phases. The first three phases a) the initial situation: it started like that! b) anchoring: it continues! and c) the impasse: being in it! are part of tolerance and the status quo, while the last two phases d), the mobilization of resources and e) the rupture are anchored in a perspective of action towards change, 3) consequences on the state of health and personal and professional well-being of the bullied or witness nurse and on the quality of care and, 4) the space-time continuum inherent in bullying situations. The theoretical co-construction reveals the life cycle of bullying situations underlying nursing practice, thus allowing us to better understand how and why this type of situation arises, occurs, transforms, and ends.
The results of this study reveal, among other things, moments conducive to professional transitions which can mark the beginning of situations of intimidation, the formation of informal alliances (cliques), internal divisions within the profession, the adaptation of the practice of the bullied nurse to her toxic work environment and the denunciation of her experience of bullying which is based on principles similar to advocacy and parrhesia in order to protect herself and ensure the safety of patients. Consequences on the health, well-being, social life, dignity, professional identity and career path of the bullied nurse or witness are noted.
This doctoral study made it possible to approach a sensitive and tacit subject such as bullying situations in an innovative way. It offers recommendations for the different fields of nursing practice and provides levers for reflection and action to promote healthy work environments. However, while contributing to the development of knowledge in nursing sciences, the present study offers a framework for understanding the bullying situations underlying nursing practice. The proposed avenues of reflection and action could allow progress in the fight against this form of violence, which is rife in certain health organizations and, potentially, in other areas of the world of work.
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Ein Beitrag zur Untersuchung des Verhaltens dünner Flüssigkeitsfilme nahe gekrümmten Substratoberflächen / A contribution to the investigation of thin liquid layer behaviour at curved solid edgesSommer, Oliver 05 November 2014 (has links) (PDF)
In der vorliegenden Arbeit wurde das Verhalten dünner Flüssigkeitsfilme an gekrümmten Substratoberflächen durch experimentelle Beschichtungsversuche basierend auf der non-invasiven laserinduzierten Fluoreszenzmesstechnik und durch numerische Filmsimulationen mit Hilfe des Volume-of-Fluid Mehrphasenmodells untersucht. Besonderes Interesse galt dabei dem Finden optimaler Einflussgrößenkombinationen zur Reduzierung des Fettkanten-Effekts. In der hierfür durchgeführten Parameterstudie wurden sowohl Applikationsparameter wie der Kantenrundungsradius und die Applikationsschichtdicke als auch Stoffparameter der untersuchten Flüssigkeit wie die Viskosität und die Oberflächenspannung variiert. Neben qualitativen Beschreibungen der entstandenen Fettkantengestalten sind als Resultate auch Größen zur Quantifizierung der Fettkanten festgelegt worden und systematisch dargestellt. Es konnte nachgewiesen werden, dass ungünstige und geeignete Parameterkonfigurationen existieren, welche prägnante bzw. kaum auffällige Fettkanten erzeugen, insbesondere im Experiment. Über die dabei eingreifenden Mechanismen der zugrundeliegenden Strömungen wurden konkrete Hypothesen aufgestellt, auch um die resultierenden Proportionalitäten der Fettkantengrößen bezüglich der Einflussgrößen zu plausibilisieren. Weiterhin konnte eine Aussage über die Signifikanz der untersuchten Einflussgrößen getroffen werden. Abschließend wurde eine geeignete dimensionslose Kenngröße generiert, um den Fettkanten-Effekt parameterübergreifend beschreiben zu können, wodurch mittels der Ähnlichkeitstheorie auch eine gewisse Abschätzung des Fettkanten-Effekts ermöglicht wird. / In this study the behaviour of a thin liquid layer at a curved solid edge was examined by experimental coating investigations based on the laser-induced fluorescence technique and by numerical film simulations based on the Volume-of-Fluid multiphase flow model, respectively. The main motivation was to find optimal combinations of influencing quantities to reduce the fat-edge effect. Therefore a study of these quantities was performed, in which application parameters like edge radii of curvature and application layer thicknesses as well as determining liquid properties like viscosity and surface tension have been varied. Results are described qualitatively at corresponding fat-edge shapes and quantified by suitable fat-edge parameters, which had to be identified and selected. It could be shown that adverse and appropriate influencing parameter combinations exist, which generate conspicuous and less distinctive fat-edges, respectively - especially in laboratory experiments. The experimental findings and proportionalities regarding fat-edge shapes and dimensions are found to be physically plausible. Furthermore an order of significance of the influencing quantities established. Eventually, a dimensionless quantity was derived by dimensional analysis, which describes the fat-edge effect. Thus, the fat-edge effect has also been described by the application of similarity theory and the corresponding dimenionless number, respectively.
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Optimalizace technologie výroby odlitků ze slitin Al metodou vytavitelného modelu / Optimized manufacturing of aluminium castings by using lost wax technologyTalanda, Ivan January 2012 (has links)
Aim of this diploma thesis is to choose new pattern wax for Fimes a.s. foundry. New wax should substitute old not fully satisfactory pattern wax which caused problems in technological process resulting in increased number of rejects. New pattern wax should eliminate current problems and help foundry with producing large, thin-walled, high-quality castings. Numbers of pattern waxes supplied by world’s leading wax manufacturers were subjected to laboratory tests and pilot study. This diploma thesis is part of project Alfa TA01010766: „Research and development of production technology large, thin and high quality castings of aluminium alloys “
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Ein Beitrag zur Untersuchung des Verhaltens dünner Flüssigkeitsfilme nahe gekrümmten SubstratoberflächenSommer, Oliver 17 October 2014 (has links)
In der vorliegenden Arbeit wurde das Verhalten dünner Flüssigkeitsfilme an gekrümmten Substratoberflächen durch experimentelle Beschichtungsversuche basierend auf der non-invasiven laserinduzierten Fluoreszenzmesstechnik und durch numerische Filmsimulationen mit Hilfe des Volume-of-Fluid Mehrphasenmodells untersucht. Besonderes Interesse galt dabei dem Finden optimaler Einflussgrößenkombinationen zur Reduzierung des Fettkanten-Effekts. In der hierfür durchgeführten Parameterstudie wurden sowohl Applikationsparameter wie der Kantenrundungsradius und die Applikationsschichtdicke als auch Stoffparameter der untersuchten Flüssigkeit wie die Viskosität und die Oberflächenspannung variiert. Neben qualitativen Beschreibungen der entstandenen Fettkantengestalten sind als Resultate auch Größen zur Quantifizierung der Fettkanten festgelegt worden und systematisch dargestellt. Es konnte nachgewiesen werden, dass ungünstige und geeignete Parameterkonfigurationen existieren, welche prägnante bzw. kaum auffällige Fettkanten erzeugen, insbesondere im Experiment. Über die dabei eingreifenden Mechanismen der zugrundeliegenden Strömungen wurden konkrete Hypothesen aufgestellt, auch um die resultierenden Proportionalitäten der Fettkantengrößen bezüglich der Einflussgrößen zu plausibilisieren. Weiterhin konnte eine Aussage über die Signifikanz der untersuchten Einflussgrößen getroffen werden. Abschließend wurde eine geeignete dimensionslose Kenngröße generiert, um den Fettkanten-Effekt parameterübergreifend beschreiben zu können, wodurch mittels der Ähnlichkeitstheorie auch eine gewisse Abschätzung des Fettkanten-Effekts ermöglicht wird. / In this study the behaviour of a thin liquid layer at a curved solid edge was examined by experimental coating investigations based on the laser-induced fluorescence technique and by numerical film simulations based on the Volume-of-Fluid multiphase flow model, respectively. The main motivation was to find optimal combinations of influencing quantities to reduce the fat-edge effect. Therefore a study of these quantities was performed, in which application parameters like edge radii of curvature and application layer thicknesses as well as determining liquid properties like viscosity and surface tension have been varied. Results are described qualitatively at corresponding fat-edge shapes and quantified by suitable fat-edge parameters, which had to be identified and selected. It could be shown that adverse and appropriate influencing parameter combinations exist, which generate conspicuous and less distinctive fat-edges, respectively - especially in laboratory experiments. The experimental findings and proportionalities regarding fat-edge shapes and dimensions are found to be physically plausible. Furthermore an order of significance of the influencing quantities established. Eventually, a dimensionless quantity was derived by dimensional analysis, which describes the fat-edge effect. Thus, the fat-edge effect has also been described by the application of similarity theory and the corresponding dimenionless number, respectively.
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DESIGN METHODS FOR LARGE RECTANGULAR INDUSTRIAL DUCTSThanga, Tharani 10 1900 (has links)
<p>A large rectangular industrial duct consists of plates stiffened with parallel wide flange sections. The plates along with stiffeners acts to resist the pressure loads and to carry other loads to the supports. The behaviours of the components of large industrial ducts are significantly different from the behaviours on which the current design methods are based on. Investigation presented herein deals with the design methods for spacing stiffeners, proportioning stiffeners and calculating shear resistance of side panel.</p> <p>Current method of spacing stiffeners is based on large deflection plate theory. A parametric study was conducted on dimensionless parameters identified in order to benefit from membrane action in partially yielding plate for spacing stiffeners. Design equations were established in terms of dimensionless pressure, plate slenderness and normalized out-of-plane deflection for three cases namely; 0%, 16.5% and 33% of through thickness yielding of the plate. Results show that approximately 50% increase in stiffener spacing when yielding of 16.5% of thickness is permitted.</p> <p>Under suction type pressure load, the unsupported compression flange and restrained tension flange lead to distortional buckling of the stiffeners. The current methods do not address distortional buckling adequately. A parametric study on dimensionless parameters governing the behaviour and strength of stiffened plat panels was conducted. The study indicated that the behaviour and strength of the stiffened panels could be a function of web slenderness and overall slenderness of the stiffener. The study also identified the slenderness limit of stiffener web for which the stiffener reaches the yield moment capacity. This study demonstrated the conservatism of current method. Finally a method was established to calculate the strength of stiffened plate panel subjected lateral pressure.</p> <p>Side panels adjacent to the supports transfer large amount of shear to the supports and, in addition, resist internal pressure. Currently the design of side panels for shear is based on the methods used for the web of fabricated plate girders. The behaviour and the characteristics between the web of plate girder and the thin side panels are significantly different. A parametric study was conducted on dimensionless parameters identified. It was concluded that the plate slenderness dominates the normalized shear strength of stockier side panels. The aspect ratio and plate slenderness influence the normalized shear strength of slender side panels. Design methods to calculate the shear strength of side panels were proposed.</p> / Doctor of Philosophy (PhD)
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