Physical Sciences and Mathematics Commons^™

Reaction Rate Of 17f(P,Γ)18ne And Its Implications For Nova Nucleosynthesis, Suzanne Parete-Koon

Masters Theses

The rate of the 17F(p,γ)18Ne reaction has a profound effect on the abundances of several isotopes produced during a nova outburst. In 1999 a new rate for 17F(p,γ)18Ne was determined from a measurement of the excitation function for the 1H(17F,p)17F reaction at Oak Ridge National Laboratory's (hereafter ORNL) Holifield Radioactive Ion Beam Facility[1]. This experiment yielded the first definite evidence of a Jπ =3+ state in 18Ne. This state provided a new resonance in the 17F +p capture, which could, depending on its properties, dominate the rate of 17F(p,γ)18Ne at stellar explosive temperatures. The new rate for 17F(p,γ) 18Ne was …

Adaptive Simulated Annealing: An Alternative Approach For The Error Minimization Of Neural Networks, Yuxing Sun

Masters Theses

This work introduces an alternative algorithm, simulated annealing, to minimize the prediction error from neural networks that traditionally use back-propagation methods. The simulated annealing algorithm stochastically samples the parameter space formed by weights of the neural network until a minimal error is found.

Three problems were investigated in this work: the radiator problem, the spiral problem, and the time series prediction problem. Each of them was examined using the same neural network architecture, i.e., a 2-layer network, and trained by both back-propagation and simulated annealing.

The simulated annealing algorithm consumes longer computation time in searching for the global minimum than …

Subaerial Paleokarst In The Upper Pennington Formation (Upper Mississippian) Limestones At Leatherwood Ford, Big South Fork, Tennessee, Sara Elizabeth Humbert

Masters Theses

The uppermost Pennington Formation (Mississippian - latest Chesterian) consists of limestone deposits, which, in some areas, contain evidence of paleokarst. A 100 m long continuous outcrop of the upper Pennington Formation was studied at Big South Fork National River and Recreation Area, in Scott County, Tennessee, using both field and petrographic methods, in order to test the hypothesis that the paleokarst is of subaerial origin.

The upper Pennington limestone section was subdivided into 4 depositional units, interpreted as recording sea-level change through the end of the Mississippian. Although there was an overall regression toward the end of the Mississippian, changes …