Thesis (Ph.D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 52-62).

Friction stir welding (FSW) is a relatively new solid-state welding technology invented at The Welding Institute of UK in 1991. It is versatile and has been widely adopted to join various materials. There has been strong research activity on revealing the details of the material flow pattern in the nugget zone induced by the conventional shoulder tool. However, there is insufficient understanding on the aspects of the scroll shoulder tool design and the shoulder flow zone formation utilizing this type of tool. The major objective of this study was to conduct experiments, analyse results and then reveal the shoulder flow zone forming mechanism for the scroll shoulder tool. The method used was to identify the flow pattern in the shoulder flow zone using a ‘marker insert’ technique, and then to suggest the forming mechanism of the shoulder flow zone based on the obtained flow pattern; although the ‘marker insert’ technique has never been used to study the shoulder flow zone flow pattern induced by the scroll shoulder tool. Experiments were conducted to examine the thick sections 6061 aluminium ‘marker insert’ welds, which were welded using a scroll shoulder tool at a range of welding parameters. These were followed by quantifying the mass of the accumulated work piece material within the scroll groove (pick up material-PUM), evaluating the effect of welding parameters on the shoulder flow zone formation, and documenting the shoulder flow zone flow pattern. The major finding was that there is a simple banded structure which forms in a layer to layer manner in the bottom portion of the shoulder flow zone, but it disappears in the top portion of the shoulder flow zone. Accordingly, the forming mechanism of the shoulder flow zone for the scroll shoulder tool was suggested as follows. Firstly, the tool pin is plunged into the work piece; the work piece material is extruded by the pin and pushed up into the scroll groove forming the PUM. Secondly, after the tool shoulder is plunged into the work piece to a certain depth, the scroll groove is fully filled up with the PUM. Finally, during the forward movement of the tool, the central portion of PUM is driven downward by the root portion of the pin and then detaches from the pin (tip portion) in a layer to layer manner. It has also found that the thickness of the shoulder flow zone varies with a thicker on the advancing side than on the retreating side, and there is a positive linear relationship between the mass of PUM and the weld quality. This study has revealed for the first time the forming mechanism of the shoulder flow zone, and has improved the understanding of the shoulder flow zone formation using a scroll shoulder tool. It is recommended that a ‘shoulder-breaking’ technique is developed to break the rotating shoulder suddenly and hence embed it into the work piece during FSW, in which a real-time shoulder-work piece couple could be produced for a better three-dimensional examination of the shoulder flow zone.

Les domaines de la réalité virtuelle et du jeu vidéo convoquent les problématiques émotionnelles dans leurs objectifs respectifs de présence et de flow zone. Cependant, la question des méthodologies d'induction d'émotions dans les environnements virtuels de ces médiums n'a pas été largement questionnée. Après avoir défini ce que sont les émotions dans la littérature philosophique, psychologique et physiologiste, nous cherchons à montrer les liens supposés existants entre l'émotion et les états extatiques de présence en réalité virtuelle et de flow zone dans les jeux vidéo. Nous commençons donc par montrer combien le niveau de connaissance des médiums peut influencer la sensibilité aux inductions d'émotions dans les environnements virtuels. Puis nous mettons en place une stratégie inductive d'émotions basée sur une gestion itérative des niveaux de challenge en lien avec les niveaux de compétences acquises. Nous avons validé au travers de deux expériences empiriques ayant impliquées 176 participants, une méthodologie d'induction d'émotions basée sur un schéma circomplexe. Ce schéma, construit autour de la valence et le niveau de charge émotionnelle, permet d'induire des émotions dans les cinq composantes essentielles de la conception d'environnements virtuels pour la réalité virtuelle ou les jeux vidéo : la chromatique, la luminosité, la vitesse des mouvements, la dimension des espaces et le volume des interactions sociales.

Friction stir welding (FSW) is a relatively new solid-state welding technology invented at The Welding Institute of UK in 1991. It is versatile and has been widely adopted to join various materials. There has been strong research activity on revealing the details of the material flow pattern in the nugget zone induced by the conventional shoulder tool. However, there is insufficient understanding on the aspects of the scroll shoulder tool design and the shoulder flow zone formation utilizing this type of tool. The major objective of this study was to conduct experiments, analyse results and then reveal the shoulder flow zone forming mechanism for the scroll shoulder tool. The method used was to identify the flow pattern in the shoulder flow zone using a ‘marker insert’ technique, and then to suggest the forming mechanism of the shoulder flow zone based on the obtained flow pattern; although the ‘marker insert’ technique has never been used to study the shoulder flow zone flow pattern induced by the scroll shoulder tool. Experiments were conducted to examine the thick sections 6061 aluminium ‘marker insert’ welds, which were welded using a scroll shoulder tool at a range of welding parameters. These were followed by quantifying the mass of the accumulated work piece material within the scroll groove (pick up material-PUM), evaluating the effect of welding parameters on the shoulder flow zone formation, and documenting the shoulder flow zone flow pattern. The major finding was that there is a simple banded structure which forms in a layer to layer manner in the bottom portion of the shoulder flow zone, but it disappears in the top portion of the shoulder flow zone. Accordingly, the forming mechanism of the shoulder flow zone for the scroll shoulder tool was suggested as follows. Firstly, the tool pin is plunged into the work piece; the work piece material is extruded by the pin and pushed up into the scroll groove forming the PUM. Secondly, after the tool shoulder is plunged into the work piece to a certain depth, the scroll groove is fully filled up with the PUM. Finally, during the forward movement of the tool, the central portion of PUM is driven downward by the root portion of the pin and then detaches from the pin (tip portion) in a layer to layer manner. It has also found that the thickness of the shoulder flow zone varies with a thicker on the advancing side than on the retreating side, and there is a positive linear relationship between the mass of PUM and the weld quality. This study has revealed for the first time the forming mechanism of the shoulder flow zone, and has improved the understanding of the shoulder flow zone formation using a scroll shoulder tool. It is recommended that a ‘shoulder-breaking’ technique is developed to break the rotating shoulder suddenly and hence embed it into the work piece during FSW, in which a real-time shoulder-work piece couple could be produced for a better three-dimensional examination of the shoulder flow zone.

Thesis (doctoral)--Universität Kiel, 1992. / Summary in English. Includes bibliographical references (p. 95-100).

Submitted by Jesiel Ferreira Gomes (jesielgomes@ufcg.edu.br) on 2018-04-18T00:27:12Z No. of bitstreams: 1 MARCELLA MAYARA COSTA ARAUJO ARAGÃO – DISSERTAÇÃO (PPGEPM) 2017.pdf: 3889032 bytes, checksum: b07ad0aff275b94b8f849a17c019fe8e (MD5) / Made available in DSpace on 2018-04-18T00:27:12Z (GMT). No. of bitstreams: 1 MARCELLA MAYARA COSTA ARAUJO ARAGÃO – DISSERTAÇÃO (PPGEPM) 2017.pdf: 3889032 bytes, checksum: b07ad0aff275b94b8f849a17c019fe8e (MD5) Previous issue date: 2017-02-23 / No gerenciamento de reservatórios petrolíferos um dos desafios é predizer o comportamento do fluxo de fluidos. A identificação das unidades de fluxo é complexa, por este motivo é necessário realizar a caracterização rochosa. Parâmetros como porosidade e permeabilidade devem ser conhecidos. O uso da estatística é útil para realizar a divisão do reservatório em zonas utilizando dados de testemunho e os perfis do poço. Esta pesquisa tem como objetivo aplicar duas técnicas alternativas, úteis para o reconhecimento de unidades de fluxo no campo de Namorado e realizar uma análise comparativa das técnicas verificando os resultados obtidos em ambas as abordagens, assim como obter o modelo tridimensional das zonas indicadas pelas técnicas. As técnicas utilizadas nesta dissertação são o zoneamento estatístico e índice de zona de fluxo (FZI). Utilizaram-se os dados de permeabilidade de quinze poços fornecidos pela Agência Nacional de Petróleo. Na primeira técnica foram calculadas as variâncias entre zonas, variâncias agrupadas dentro das zonas e por fim o índice de zoneamento com o qual foi possível a divisão de zonas. Na aplicação da técnica FZI o maior valor do índice indicou a profundidade de divisão entre zonas. Após a obtenção das zonas foram construídos dois modelos, o primeiro baseado no zoneamento estatístico, indicando as zonas; e o segundo baseado no FZI, apontando a localização das zonas correspondentes ao reservatório e aquelas associadas ao não-reservatório. Para a construção dos modelos tridimensionais utilizou-se o software geoestatístico SGeMS. De acordo com os resultados obtidos ficou evidenciado que as técnicas de zoneamento estatístico e FZI têm produzido resultados equivalentes em alguns poços, mas divergentes em outros. No entanto, o método FZI apresentou, na maioria dos poços, resultados mais satisfatórios em comparação ao zoneamento estatístico. / In oil reservoirs management one of the challenges is to predict the behaviour of the fluid flow. Identifying the flow units is complex task, therefore it is necessary to perform the characterization of rocks. Parameters such as porosity and permeability must be known. The use of statistics is useful to perform reservoir division into zones using core data and geophysical well logs. This research aims to apply two alternative well established techniques useful for the recognition of flow units in the Namorado field and conduct a comparative analysis of the techniques by looking at the results obtained in both approaches, as well as obtain the three-dimensional model of this field, as indicated by both techniques. The techniques used in this work are statistical zoning and flow zone index (FZI). In this research was used permeability data from 15 wells provided by the Brazilian National Petroleum Agency. In the first technique were calculated the variances between zones, grouped variances within zones and finally the zoning index with which it was possible divide the field into zones. On application of FZI the greatest value of the index indicated the depth of division between zones. After zones recognition, two model were constructed, the first one based on statistical zoning, indicating the zones; and the second based in FZI, pointing out the location of the zones corresponding to the reservoir and those associated with the nonreservoir. For the construction of three-dimensional models the geostatistical software SGeMS was used. According to the obtained results was evidenced that the techniques of statistical and FZI zoning have produced equivalent results in some wells, but different in others. However, the FZI method presented, in most wells, more satisfactory results compared to the statistical zoning.