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Full-Text Articles in Physics
Performance Impact Of Different Lower-Limb Setup Positions In The Backstroke Swimming Start, Gordon E. Barkwell
Performance Impact Of Different Lower-Limb Setup Positions In The Backstroke Swimming Start, Gordon E. Barkwell
Electronic Thesis and Dissertation Repository
The performance impact of different knee extension angles in the setup position for a backstroke start was evaluated using an instrumented starting surface. Ten backstroke swimmers completed maximum-effort starts in each of two setup positions: one with the knees flexed, and one with the knees extended. The start handles and touchpad were instrumented with tri-axial force plates. Activity of major hip and knee extensors was measured using surface electromyography. Body position was recorded throughout the start using two high-speed cameras. There was no difference in time to 10 m between the two conditions, indicating there is likely no advantage in …
Optimization Of Design Procedures For Delta Relaxation Enhanced Magnetic Resonance, Daniel J. Martire
Optimization Of Design Procedures For Delta Relaxation Enhanced Magnetic Resonance, Daniel J. Martire
Electronic Thesis and Dissertation Repository
Delta relaxation enhanced magnetic resonance (dreMR) is a magnetic resonance imaging (MRI) method that produces contrast based on longitudinal relaxation dispersion. Through modulation of the magnetic field using an actively-shielded, field-cycling insert coil, this technique increases probe specificity and suppresses remaining signal. However, significant improvements are needed. This thesis addresses two advancements in dreMR with a focus on optimizing design procedures. A general procedure was developed to design split power solenoid magnets. The procedure was then applied to the design of a switched-field exposure system. A coil was constructed and the method was validated. This procedure can be used for …