Engineering Commons^™

Development Of A Low-Dose Radiation Therapy Device For Acute Respiratory Distress Syndrome, Thomas Heath Davis

Doctoral Dissertations

This research focuses on developing a low-dose radiotherapy (LD-RT) device for treating acute respiratory distress syndrome (ARDS). This respiratory illness affects millions of people a year. Using orthovoltage (200 – 500 keV) X-ray energy provides many advantages over traditional radiotherapy delivery with linear accelerators, such as low cost and greater accessibility. In addition, X-ray tubes have been shown throughout history to provide good treatment outcomes for pneumonia, and research has shown LD-RT to be just as effective with ARDS. This proposal summarizes my efforts in determining the dosimetric properties of an LD-RT system to deliver treatment quickly and effectively. My …

Nuclear Thermal Rocket Engine Instrumentation Addressing Environmental Limitations On Temperature Measurements, Dan C Floyd

Doctoral Dissertations

The development of nuclear thermal rockets has received renewed interest in recent years due to the benefits that can attained from this method of propulsion. Currently, instrumentation work is focused on the evaluation of current and near-term technology for implementation within a nuclear thermal rocket engine. One aspect of this evaluation is focused on the various instrumentation requirements of the system regarding necessary measurement parameters and environmental conditions for survivability. Historical nuclear rocket programs that have been conducted in the United States provide the basis for this information and indicates a critical need for high temperature measurement technology that can …

Semi-Implicit Direct Kinetics Methodology For Deterministic, Time-Dependent, Three-Dimensional, And Fine-Energy Neutron Transport Solutions, James Ernest Banfield

Doctoral Dissertations

Using a semi-implicit direct kinetics (SIDK) method that is developed in this dissertation, a finer neutron energy discretization and improved fidelity for transient radiation transport calculations are facilitated to reduce uncertainties and conservatisms in transient power and temperature predictions. These capabilities are implemented within a parallel computational solver framework, which is able to represent an arbitrary number of neutron energy groups, angles, and spatial discretizations, while internally coupled to an unstructured finite element multi-physics code for temperature and displacement calculations. This capability is demonstrated on a three-dimensional control rod ejection simulation run in parallel utilizing forty-four neutron energy groups.

An …