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Empirical Dynamic Modeling And Nonlinear Force Control Of Friction Stir Welding, Xin Zhao

Masters Theses

"Current Friction Stir Welding (FSW) process models are mainly concerned with the detailed analysis of material flow, heat generation, etc. and therefore, are computationally intensive. Dynamic models describing the total forces acting on the tool throughout the entire welding process are required for the design of feedback control strategies and improved process planning and analysis. In this thesis, empirical models relating the process parameters (i.e., plunge depth, travel speed, and rotation speed) to the process variables (i.e., axial, path, and normal forces) are developed to describe their dynamic relationships"--Abstract, page iv.

Modeling And Control Of Freeze-Form Extrusion Fabrication, Xiyue Zhao

Masters Theses

"Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing technique that extrudes ceramic loaded aqueous pastes layer by layer below the paste freezing temperature for component fabrication. As the FEF is aimed at being conducted at low environmental temperatures, down to -20°C, it is necessary to investigate the effect of environmental temperature on the process. The advantages of fabrication at low temperature have been proved by experiments. Comparisons in terms of operation parameters, self-sustaining ability, and system dynamic response were performed at different environmental temperatures ranging from 20°C to -20°C.

It is commonly known in paste extrusion processes that due to …

Hunger-Related Intrusive Thoughts Reflect Increased Accessibility Of Food Items, Lisa Marie Berry, Jackie Andrade, Jon May

School of Psychology

No abstract provided.

Custom-Made Total Contact Insoles And Prefabricated Functional Diabetic Insoles: A Case Report, J Paton, E Stenhouse, R Jones, G Bruce

School of Health Professions

Insoles are commonly prescribed to offload the mechanical stresstransmitted to the plantar tissues of the foot. Traditionally, thecustom-made total-contact insole (TCI) is favoured over itsprefabricated counterpart. The introduction of a new prefabricateddiabetic insole (A Algeo Ltd, Liverpool) designed to modify footbiomechanics may offer an instant, low-cost, clinically-effectivealternative. We report on a comparison of the two insoles in thecase of a 54-year-old woman with type 2 diabetes and peripheralneuropathy, presenting with ulceration overlying the thirdmetatarsal region. The F-scan in-shoe pressure measurement system(TEKSCAN) provided an objective measure of effect.

Performance Improvement Of Adaptive Filters For Echo Cancellation Applications, Deepak Challa

Masters Theses

"This work focuses on performance improvement of adaptive algorithms for both line and acoustic echo cancellation applications. Echo in telephone networks, Line Echo, is observed naturally due to impedance mismatches at the long-distance/local-loop interface. Acoustic echo is due to the acoustic coupling between the microphone and the speaker of a speakerphone. The Affine Projection (APA) and the Fast Affine Projection (FAP) algorithms are two examples of reliable and efficient adaptive filters used for echo cancellation...This thesis presents, Variable Regularized Fast Affine Projections (VR-FAP) algorithm, with a varying, optimal regularization value which provides the desirable property of both fast and low …

Soil Fertility And Productivity Relationships In Rice Production System, Bangladesh, S Rahman, Rj Parkinson

School of Geography, Earth and Environmental Sciences

This paper presents an econometric analysis of the influence of soil fertility status on productivity and resource use in rice production utilizing survey data from 21 villages in three agro-ecological regions of Bangladesh. Detailed crop husbandry input-output data were collected from 380 paddy rice (Oryza sativa) farmers. Data collected included fertilizer, pesticide, labour, animal power services, irrigation, farm capital assets and rice yield. The soil fertility status in each region was determined by analysis of soil organic carbon, available nitrogen, phosphorus and potassium concentration. Analysis was based on a profit function, where the selected soil fertility parameters were incorporated as …

Planktic Foraminifera From The Proposed Gssp For The Oxfordian Stage: Redcliff Point, Near Weymouth, M.B. Hart, T. Aze, W. Hudson, C.W. Smart

School of Geography, Earth and Environmental Sciences

In the course of the stratigraphical and palaeontological investigations for the Global Stratotype Section and Point (GSSP) for the base of the Oxfordian Stage at Recicliff (near Weymouth) an assemblage of planktic foraminifera has been described. Planktic foraminifera are exceptionally rare in the Jurassic of the United Kingdom and only a few records have been reported in the last few years. At Redcliff, the assemblage is preserved as pyrite steinkerns, but the fauna contains a number of morphotypes which match onto known species from this interval (Globuligerina oxfordiana, Compactogerina stellapolaris) while others have no described species to which they can …

Experimental Investigation Of Temperature And Tool Wear In High Speed End-Milling Of Titanium Alloy, Benjamin Nwakile Oguejiofor

Masters Theses

"This thesis presents the results of experimental investigation of temperature and tool wear in high speed end-milling of titanium alloy. The investigation of cutting parameters on temperature in high speed end-milling of thin-walled titanium structure was conducted on Cincinnati Milacron Sabre 750 Vertical Machining Center using a 1/2 Fractional Factorial Design of Experiment with 3 factors at 2 levels each. Data logging of temperature data was carried out using VI logger software. Tool tip temperature at the comers and center of the pocket was estimated. All the factors investigated were found to have a significant effect on workpiece temperature. Radial …