A generalized, three-dimensional, finite element bridge model was created in order to efficiently and accurately assess live-load girder distribution factors for a variety of bridge types. This model shortens the time required by bridge analysts to develop individual finite element models for bridges of varying geometries. The creation of the...
Hydrogels have been attractive for use as a medium in porous flow studies,
but have always been limited in this role because of their poor mechanical properties.
This project analyzes and tests two recently developed hydrogels,
poly(methacrylamide-co-methacrylic acid) (PMM), and a heat-treated long chain
PVA hydrogel. Particle image velocimetry (PIV)...
The quality and availability of forage fishes and invertebrates can affect the behavior and productivity of predators that rely on these resources. This study measures the proximate composition of forage fishes and invertebrates from the southeastern Bering Sea to estimate prey energy density (quality) using a method that is ecologically...
Understanding how the interactions and feedbacks between plant function, climate, and soils ultimately affects the terrestrial water balance and subsurface flow processes is major challenge in scientific hydrology. This dissertation summarizes the findings of a manipulative climate warming experiment, an observational field study that utilized stable-isotope tracers, and associated modeling...
Remote sensing techniques have long been useful in quantifying changes in ecosystems and the field of remote sensing is constantly evolving to better assess and describe changes, both spatially and temporally. In this thesis I explored the novel use of two remote sensing methods to quantify ecosystems; repeat photograph to...
I conducted a field study using gray wolf and mountain lion urine to investigate white-tailed deer and mesopredator behavioral responses to novel predator cues in a natural setting and to see if any changes in wildlife activity correspond to changes in the local biodiversity of a wetland environment. I created...
Following their extirpation due to the maritime fur trade, northern sea otter (Enhydra lutris kenyoni) reintroduction in the 1960s has facilitated their recolonization in southeast Alaska. Sea otters are now sympatric with wolves (Canis lupus), which are widespread in southeast Alaska, and a colonizing coyote population (Canis latrans). Recent studies...
The finite element software framework, OpenSees, has been used by researchers
to simulate the response of structural and geotechnical systems to earthquake loading. Implementation of the Particle Finite Element Method (PFEM) has made it possible to simulate hydrodynamic forces through fluid-structure interaction (FSI) in OpenSees. To validate the FSI implementation...
The goal of this phase of the study was to develop a model of the Tualatin River incorporating Scoggins Creek and Hagg Lake. This tool will be used in conjunction with a hydrologic model, the EPA HSPF model (Johnson, Imhoff, and Kittle, 1984), to analyze management strategies to improve water...
The notion of a normal number and the Normal Number Theorem date back over 100 years. Émile Borel first stated his Normal Number Theorem in 1909. Despite their seemingly basic nature, normal numbers are still engaging many mathematicians to this day. In this paper, we provide a reinterpretation of the...