Role of atomic coordination on superconducting properties of boron-doped amorphous carbon

We study the effect of atomic coordination (orbital hybridization) on superconducting properties of boron-doped amorphous carbon. The ratio of threefold coordinated (sp2-hybridized) and fourfold coordinated (sp3-hybridized) atoms in the system is found to have an impact on their electronic, vibrational, and superconducting properties. Our findings show that a high proportion of fourfold coordination in both carbon and boron atoms is important for realizing a high superconducting transition temperature

Sharp Fronts Due to Diffusion and Viscoelastic Relaxation in Polymers

A model for sharp fronts in glassy polymers is derived and analyzed. The major effect of a diffusing penetrant on the polymer entanglement network is taken to be the inducement of a differential viscoelastic stress. This couples diffusive and mechanical processes through a viscoelastic response where the strain depends upon the amount of penetrant present. Analytically, the major effect is to produce explicit delay terms via a relaxation parameter. This accounts for the fundamental difference between a polymer in its rubbery state and the polymer in its glassy state, namely the finite relaxation time in the glassy state due to slow response to changing conditions. Both numerical and analytical perturbation studies of a boundary value problem for a dry glass polymer exposed to a penetrant solvent are completed. Concentration profiles in good agreement with observations are obtained

Nonlinear Properties of the Semiregular Variable Stars

We demonstrate how, with a purely empirical analysis of the irregular lightcurve data, one can extract a great deal of information about the stellar pulsation mechanism. An application to R Sct thus shows that the irregular lightcurve is the result of the nonlinear interaction of two highly nonadiabatic pulsation modes, namely a linearly unstable, low frequency mode, and the second mode that, although linearly stable, gets entrained through a 2:1 resonance. In the parlance of nonlinear dynamics the pulsation is the result of a 4 dimensional chaotic dynamics.Comment: 8 pages to appear in "Mass-Losing Pulsating Stars and Their Circumstellar Matter", Eds. Y. Nakada & M.Honma, ASSL Ser. (in press). a version with better quality figures is available from http://www.phys.ufl.edu/~buchler

Shock Formation in a Multidimensional Viscoelastic Diffusive System

We examine a model for non-Fickian "sorption overshoot" behavior in diffusive polymer-penetrant systems. The equations of motion proposed by Cohen and White [SIAM J. Appl. Math., 51 (1991), pp. 472–483] are solved for two-dimensional problems using matched asymptotic expansions. The phenomenon of shock formation predicted by the model is examined and contrasted with similar behavior in classical reaction-diffusion systems. Mass uptake curves produced by the model are examined and shown to compare favorably with experimental observations

The Assessment of Clinical Reasoning in Preceptors Across the Athletic Training Profession

Clinical reasoning (CR) is defined as a complex multi-factorial metacognitive process for diagnosis formulation. Clinical reasoning begins as a student and develops over a career. Students are typically taught an analytical approach defined as hypothetico-deductive reasoning (HDR). Expert clinicians use a non-analytical approach defined as the Knowledge Based Model (KBM) of CR. It is accepted that clinicians use the KBM with cases that they have more experience to streamline the evaluation process. Unfortunately, because of the nuance of CR there have been limited investigations within athletic training to evaluate CR outside of the student population. The overarching purpose of this dissertation was to investigate CR in athletic training preceptors. To achieve this purpose, three interrelated projects were conducted. The first project involved a systematic review to investigate the use of the Diagnostic Thinking Inventory (DTI). The second project assessed clinical reasoning using the Diagnostic Thinking Inventory for Athletic Trainers (DTI-AT) in athletic training preceptors. The second project was guided by the Longitudinal Framework for Fostering Critical Thinking and Diagnostic Reasoning to establish appropriate demographic questions associated with CR development. The final project explored preceptors’ perceptions of CR in athletic training. The systematic review confirmed that the DTI was a valid, reliable, and widely used instrument to assess CR in healthcare professions. The instrument was used in medicine, physiotherapy, and athletic training. Project II indicated that the athletic training preceptors studied scored higher on the DTI than the averages of all other professions assessed in the literature, however, all other professions included both students and professionals. Professional sociability was found to be the only demographic factor related to higher scores on the DTI-AT. This finding contrasted with the Longitudinal Framework for Fostering Critical Thinking and Diagnostic Reasoning. Project III identified that CR processes in athletic training are highly variable between individual clinicians based on their experiences, confidence, patients, and external factors. Findings from these three projects indicate the importance of continued CR assessment of athletic training professionals, inclusion of soft skills in athletic training education, and encouraging professional sociability both inter- and intraprofessionally

Nonlinear Analysis of Irregular Variables

The Fourier spectral techniques that are common in Astronomy for analyzing periodic or multi-periodic light-curves lose their usefulness when they are applied to unsteady light-curves. We review some of the novel techniques that have been developed for analyzing irregular stellar light or radial velocity variations, and we describe what useful physical and astronomical information can be gained from their use.Comment: 31 pages, to appear as a chapter in `Nonlinear Stellar Pulsation' in the Astrophysics and Space Science Library (ASSL), Editors: M. Takeuti & D. Sasselo