Ever since composite laminate technology was introduced into the aerospace and automotive industry, there has been a need to fully understand the damage progression experienced by composite laminated plates in the presence of a notch. While numerous research studies have been conducted on this matter when subjected to in-plane loads,...
Cavitation instabilities in elastic-plastic solids under spherically-symmetric and axisymmetric loadings were investigated using the finite element method. Both quasi-static and dynamic analyses were used to solve these problems. In the quasi-static analyses, we investigated a cavitation instability in elastic/perfectly-plastic, linear hardening elastic-plastic, power hardening elasticplastic, and constrained silver materials. Here,...
The object of this research, project was to study how
different parameters effect the magnitude and frequency
composition of forces exerted on simulated heat exchange
tubes immersed in a cold fluidized bed. Two arrays of
tubes were assembled with the tubes mounted in an
equilateral triangular pitch pattern. The center...
A need exists to develop a non-destructive testing technique that can identify
the formation and propagation of diagonal tension cracks in conventionally
steel reinforced concrete deck girder (RCDG) highway bridges in the State of
Oregon. Such a technique could be included into a structural health
monitoring (SHM) system installed on...
This thesis presents two related studies on the methodology for creating, and
subsequently analyzing, an inverse food web model of an intertidal seagrass bed. The first study (Chapter 2) describes, for the first time in the literature, a method for incorporating isotopic information gained from Bayesian mixing models into an...
In the southern Fish Creek Range, Nye County Nevada,
Devonian rocks are found overlying younger rocks. These
Devonian units are allochthonous blocks that slid by
gravity into their present positions.
The allochthonous blocks represent several different
provenances commonly found to the west and northwest of the
area. The blocks include...
Understanding the tradeoff between water use and productivity is critical for modeling growth of intensively managed Douglas-fir forests in the Pacific Northwest. Evapotranspiration is closely linked to carbon dioxide intake during the process of photosynthesis. However, summer drought characterizing the growing season in this region imposes a limit on carbon...
Three viruses were isolated from dahlias using a modification of
Yarwood's leaf-disc method of inoculation. Two of these isolates have
been reported previously in dahlias. In addition, a fourth virus was
isolated using a liquid-nitrogen transmission technique.
Dahlia virus isolate 1 possessed host range and thermal inactivation
properties similar to...
Observations of bacterial soft rot of onions in the Lake Labish
area in the Willamette Valley of western Oregon showed that two distinct
symptom types occur during the growing season. The most
prevalent symptom type appears in infected plants as a wilting and
chlorosis of two or more lower leaves...