Pulsed laser deposition was used to create 0.1-Bi(Zn₀.₅ Ti₀.₅)O₃-0.9-BaTiO₃ (BZT-BT) thin films to examine the effects of laser energy (2.25 or 2.5 J/cm²) , pulse frequency (2 Hz or 5 Hz), and deposition temperature (550, 600, 650, and 700°C) on the electrical properties of the films. These effects were analyzed...
This dissertation focuses on the evolutionary forces of genetic drift and gene flow in frog populations. The balance of these two forces and the force of mutation largely determine the amount of neutral genetic variation within populations as well as the degree of genetic similarity among populations. The stochastic evolutionary...
Optical tweezers are capable of trapping micron sized particles through the transfer of
the momentum of light. These capabilities are expanded through the use of computer
controlled holograms for beam shaping. This hologram creation is facilitated through the use of
a spatial light modulator, which is a liquid crystal device...
In this dissertation, I present electronic spectra of a few polycyclic aromatic hydrocarbons (PAHs): tetracene, pentacene, pyrene, benzo[g,h,i]perylene and benzo[a]pyrene using resonantly enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron spectroscopy. The work of tetracene and pentacene also combine a laser desorption source with a ZEKE spectrometer, demonstrating...
Cyanobacteria are photosynthetic bacteria capable of producing toxins, including complex cyclic peptides called microcystins. Hazardous cyanobacterial blooms are an emerging public health concern and are monitored throughout Oregon in various recreational and drinking water bodies. Oregon has been proactive and responsive to the problems associated with toxic cyanobacterial blooms, but...
This paper empirically examines the effects of population aging on international trade using a cross-country panel data set for a select group of 22 OECD countries. Other recent studies have examined the effects of population age on other economic variables such as growth, savings, and investment but none till now...
Proanthocyanidins (PACs) containing A-type linkages, like those found in cranberry, have been implicated as beneficial phenolic compounds in human health, but much research is still required to better understand their activity fully. One major impediment to progress has been the existence of effective analytical methods for A-type PAC quantification. This...
Locating archaeological sites that predate the arrival of modern sea level has been difficult along the Oregon coast. This is in part believed to be the result of geologic processes that have influenced the preservation, distribution, and visibility of sites within the Oregon coastal landscape. Because of these changes, researchers...
Increasing numbers of children are entering kindergarten without the behavioral skills needed to cope with the demands of the classroom environment. Moreover, a number of studies have documented that young children's behavioral regulation (including attention, working memory, and inhibitory control skills) plays an important role in later academic achievement (McClelland,...
Originally used as a method to densify loose soils, controlled blasting has expanded its applicability to geotechnical engineering by becoming a research tool to physically generate liquefaction for full-scale in-situ tests, ranging from seismic performance of deep foundations to evaluating ground improvement techniques. Current methods used to design the blasting...