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Intergranular Phases In Cyclically Annealed Yba2cu3o7-X And Their Implications For Critical Current Densities, Andrew Peter Clarke
Intergranular Phases In Cyclically Annealed Yba2cu3o7-X And Their Implications For Critical Current Densities, Andrew Peter Clarke
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
We report changes in the intergranular material and grain morphology of YBa2Cu3O7-x during cyclic anneals between 780 and 980 ºC in oxygen at atmospheric pressure. Two endothermic reactions were detected: (a) the eutectic reaction of YBa2Cu3O7-x with CuO and BaCuO2 at 900 ºC (enthalpy ∆Ha) and (b) the peritectic reaction of YBa2Cu3O7-x with CuO at 950 ºC (∆Hb). During the first anneal, only reaction (b) is detected, and although it should only occur if there is an excess of CuO, …
A Collection Of New Studies Using Existing And Proposed Techniques And Instrumentation For Nondestructive Testing And Analysis Of Concrete Materials And Structures, Shane D. Boone
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A variety of studies were performed using existing and newly proposed techniques and instrumentation to further the understanding of nondestructive testing of concrete. A new combined stress wave propagation method was developed that combined the existing methods of the spectral analysis of surface waves, impact echo, and free-free resonant column experimental and analysis techniques. The method was used to determine the stiffness profile and location of embedded voids in a concrete tunnel lining modeled as a three layer concrete slab. A new equation was proposed that predicted the level of damage of concrete samples based on the functions of the …