Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on September 28, 2009. Major professor: Dr. Joseph Mello. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Mechanical Engineering." "June 2009." Includes bibliographical references (p. 69).

In this paper a 2D coupled thermal-stress finite element model is established and used to predict thermal phenomena at the disc-pad interface of a disc brake system. The importance of certain critical settings and parameters for the 2D FE model has been identified (such as, a limited degree of freedom for a brake pad in place of accepted practice that considers uniform contact), here a non-uniform pressure distribution resulting from friction bending moment effects due to the introduction of a pivot point. These parameters affect the distributions of both interface temperature and pressure. The simulation results show that when the interface conductance h is 10^6 W/m^2K or higher, the interface temperature distribution is no longer sensitive to friction bending moment effects. However, when h is 30000 W/m^2K or lower, the interface temperature distribution and heat partition ratio are significantly affected by the setting used for the rotational degree of freedom of the pad. The simulation results provide a useful reference for a better design of a disc brake system for different applications.

As in all other electrical equipments it is essential to estimate the temperature distribution in transformer components in the design stage and during the operation since temperatures above thermal limits of these components might seriously damage them. Thermal models are used to predict this vital information prior to actual operations. In this study, a three dimensional model based on the Finite Element Method (FEM) is proposed to estimate the temperature distribution in the three phase, SF6 gas insulated-cooled power transformer. This model can predict the temperature distribution at the specific discredited locations in the transformer successfully.

As in all other electrical equipments it is essential to estimate the temperature distribution in transformer components in the design stage and during the operation since temperatures above thermal limits of these components might seriously damage them. Thermal models are used to predict this vital information prior to actual operations. In this study, a three dimensional model based on the Finite Element Method (FEM) is proposed to estimate the temperature distribution in the three phase, SF6 gas insulated-cooled power transformer. This model can predict the temperature distribution at the specific discredited locations in the transformer successfully.

This study considers the market of potatoes in Amazonas, Peru from an informal production sector to a more formal retail-marketing sector. I consider and challenge current understandings that attempt to model formal/informal markets sectors. Those include state involvement in economic processes, wage structure and social security mechanisms, and size and organizational techniques. As, well I suggest that the method of transfer would be a useful addition to the work that attempts to model and define formal and informal economic sectors. I do so because of the importance of trust in economic exchange. In this study, these four models are reframed in terms of hypotheses to see which can most systematically explain increased formality along the market channel from production to retail marketing. I find that only two can. Those are state involvement and method of transfer and trust. Research methods include open-ended interviews (n=25) and participant observation.

An investigation into the thermo-mechanical closure effect when a fluid leaks through a crack is presented here. The extended finite element method is the modelling scheme adopted for this, and the application of heat flux and pressure jump conditions along the crack is one of the novel contributions of this work. By modelling the fluid as one dimensional steady state and obtaining a heat transfer coefficient, it has been shown here that coupling the fluid with the structure is possible all within a single element. Convergence studies done with analytical models as a benchmark demonstrate the accuracy of the new method. Simulations are performed with the new element for conditions seen in both gas cooled and water cooled reactors. Significant crack closure is observed when the bulk fluid temperature is 20oC hotter than the structure. It was also found that the amount of closure due to crack wall heating varies depending on the external boundary conditions, this is quantified in the thesis.

This thesis deals with a procedure for determining the complete processing of aerodynamic flow instabilities (rotating stall and surge) in a centrifugal compressor. At small flows the performance of a compressor system is limited by the surge line, which is caused by flow instabilities. Numerical solution is obtained using the method of transfer matrix. This system is simulated through several models with local resistances that represent the dissipation of pressure energy. Pulses are excitated in these models by the pressure jump placed before the centrifugal compressor. From the frequency-amplitude characteristics for the selected range of frequencies and flow the impedance characteristic of the compressor system is determined. We are looking for problematic frequencies in this characteristic that cause flow instabilities in the compressor system.

Purpose – The paper reports on an ongoing research project of TU Dresden Laboratory of Knowledge Architecture aiming the investigations of the traceability and visualization of upcoming ideas and topics within discussions. Communication and conversation analysis – to explore knowledge processes communication and interaction analyses emerged as a central scientific approach. Hereby knowledge creation and Knowledge Transfer are understood as collective and co-creative effort. Corresponding analysis tools and methods have been developed for the communication- and knowledge creation processes digital media extensively (Faraj et al 2011). However, research focusing on direct and immediate conversation, and not only based on digital media, rarely exists. Development requirements – The existing tools for the analysis of digital communication data are yet not widely applied in the domain of spoken discussions. Whereas communication processes in the digital domain create their data automatically, the data from natural settings have to be extracted laboriously (Tonfoni 2004). Since there are no effective methods on data recording of voice communication yet existing, there are no strong and evident methods on computer aided conversation tracking and analysing existing too. The Ideagram tool tries to overcome this shortcoming. Approach – A prototype of a transcription, visualization and analysis tool was designed, which is able to capture discussions by keywords and analyse them in real-time. The results are presented in several forms: histograms, semantic networks and mixtures between both. These visualizations allow identifying topic and concept dynamics, heuristic paths and creative moments. Central features of the discussion like knowledge communication, orientation for innovation and speech efficiency can be understood and designed. In the different figures - Ideagram - of spoken discussions the logged content is visualised. The program prototype counts the occurrence of the logged words. These can be marked within a chronological re-presentation graph and shows at what time which issue was discussed. By “peaks” and “valley’s” it is obviously visible where the talk was most or least active. The prototype tool allows analysing the used phrases according to their frequency and their appearance during the captured conversation. Practical implications & Value – In contrast of conventional protocol and transcription techniques this kind of knowledge mining allows a greater information bandwidth and a more efficient access on core topics, thematic conflicts, idea generation etc. Experiences in very different settings created a very rich data set and allows to state that the application in business and science seems to very useful according to recording, analysing and deepening of spoken discussions. Hence, the Ideagram is still a prototype version and need further investigation and development.