Spacecrafts experience radiation in the course of their operation
and all electronic equipment on board these spacecrafts has to
be designed to withstand the effects of this radiation.
This thesis describes the effects of total ionization dose (TID)
and single event transients (SET) in phase-locked loops - an
important circuit...
Circuits operating outside the earth’s atmosphere are more vulnerable to cosmic radiation and require special design consideration. The purpose of this work is to explore methods of mitigating the effect of radiation in phase locked loop (PLL) circuits. Several voltage controlled oscillators (VCOs) and two complete PLLs are designed and...
My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial and aquatic systems. I used meta-analysis to quantify the effects of UVB radiation on a diversity of aquatic organisms (Chapter 2). UVB...
Delayed tree mortality is an unpredictable occurrence when prescribed burning is implemented. Fire scorched trees may die as the result of crown scorching, stem charring, root injury, bark beetle attack, or through a combination of these factors. This study examined ponderosa pine mortality and the incidence of two bark beetle...
Ultraviolet-B radiation (UVB) is an abiotic stressor in both terrestrial and aquatic systems. The stratospheric ozone layer, depleted due to anthropogenic activities and the cause of elevated UVB at earth's surface over the last four decades, is predicted to recover by 2065. However, UVB levels in aquatic systems may continue...
There has been increased concern about radiation dose to the female breasts, with approximately 200,000 new breast cancers being diagnosed each year in the United States. The unprecedented increase in the use of radiologic exams on younger women has also raised some additional concerns about how procedures are performed. The...
The Demonstration of Ecosystem Management Options (DEMO) study is a large-scale, multi-year, interdisciplinary project examining the effects of various levels and patterns of green-tree retention on multiple forest features. Six retention levels and patterns were examined and replicated across six blocks of predominately Douglas-fir forested land in western Oregon and...
Ultraviolet-B radiation (UV-B) has been suggested as a factor contributing to global amphibian population declines. While ambient UV-B levels damage the eggs and embryos of some amphibian species, few studies have addressed how UV-B affects other life history stages or sublethal responses. My dissertation focuses on (1) investigations of sublethal...
Quantitative procedures were developed to determine the effect of variability in the model parameters required for the estimation of microbial shelflife and thermal processing time. Monte Carlo simulations combined with these predictive models were implemented in Microsoft Excel™. In the first study,
predictive models were used for shelf-life predictions based...