ROSS (Robotic Oceanographic Surface Sampler) is an autonomous boat, equipped with oceanographic sensors, used for studying the ocean’s surface. One of its advantages over traditional research vessels is its ability to sample near glaciers, an area too dangerous for manned ships. In order to properly ascertain deep ocean heat’s effect...
This dissertation investigates the dynamics of the tidally modulated outflow from the Columbia River mouth using high resolution measurements of velocity, density and turbulent microstructure. At high tide, flow through the river mouth reverses from flood (onshore) to ebb (offshore). During ebb, buoyant fluid issues from the river mouth and...
Tide-topography coupling is important for understanding surface-tide energy loss, the intermittency of internal tides, and the cascade of internal-tide energy from large to small scales. Although tide-topography coupling has been observed and modeled for 50 years, the identification of surface and internal tides over arbitrary topography has not been standardized....
In this thesis, I investigate the organization of eelgrass (Zostera marina L.) and mesograzer communities across local and regional scales in three upwelling- influenced estuaries located along the Oregon coast, USA. Eelgrass ecosystems are an important source of primary production in estuarine systems, providing numerous ecosystem services, including nursery habitat...
The dissertation examines the effect of two separate yet significant individual level factors—physical and cognitive traits—on entrepreneurial outcomes. The physical factor on which the dissertation focuses is the entrepreneur’s vocal cues and the cognitive traits that the dissertation investigates are the entrepreneur’s goal orientation and his/her ability to take perspectives....
In this three-essay dissertation I explore how CEOs’ self-serving motivation, specifically driven by their relative pay standing and celebrity status, is useful for advancing the understanding of executive behavior and strategic decision-making. In the first essay, focusing on CEOs’ motivation to reduce the dissonance caused by pay inequity, I examine...
Estimating the hydraulic conductivity of earth materials is important for many water resource modeling efforts, including predicting the transport of pollutants in ground water, computing surface runoff for flood control, and computing water budgets. This research implicitly used topography, soil, and climate data to estimate plausible continuous hydraulic conductivity values...
The shallow, poorly-confined, sand and gravel aquifer underlying the lower
Malheur River basin is contaminated by nitrate and metabolites of the herbicide
dimethyl tetrachloroterephthalate (DCPA), first detected in 1983 and 1985,
respectively. The aquifer supplies water for the Ontario municipal water system,
domestic and industrial uses, and irrigation. In response...
The objective of this study was to develop a numerical model for the movement
and fate of chlorinated phenols in groundwater. In the first part, a numerical model for
several different equilibrium and nonequilibrium sorption processes under isothermal
conditions is developed for one-dimensional, steady-state water flow in soil columns.
The...
Studies are currently underway to determine the suitability of Yucca Mountain
in Nevada as the nation's first high-level nuclear waste repository. Values of net
infiltration are required to determine pre-waste emplacement groundwater travel times
and the performance of the repository as a waste containment system. The objective of
this study...
Estimates of average annual precipitation (AAP) are-needed for hydrologic modeling at
Yucca Mtn., Nevada, site of a proposed, high-level nuclear waste repository. Historical
precipitation data and station elevation were obtained for stations in southern Nevada and
southeastern California. Elevations for 1,531 additional locations were obtained from
topographic maps. The sample...
Groundwater resources have become seriously threatened
due to improper use by industrial, municipal, and even public
sectors. Widespread contamination of aquifer systems has
jeopardized human health and the environment and methods for
restoring these systems are needed. Biological and chemical
in situ remediation, where contaminants are degraded within
the natural...
Understanding the transport and retention of radionuclides in the environment is important for protecting freshwater supplies and minimizing impact to biologic systems. Technetium-99 (Tc⁹⁹) is a radionuclide of interest due to its long half-life (2.13 x 10⁵ years) and toxicity. In the form of pertechnetate (TcO₄⁻), Tc is expected to...
Understanding the processes involved in the transport of dissolved gas plumes in groundwater aquifers is essential for comprehending the effect that these transport processes can have on site characterization and remedial design applications. Previous laboratory and field studies have indicated that dissolved gas transport in groundwater can be greatly affected...
Groundwater at Oak Ridge National Laboratory's Field Research Center (FRC) is contaminated with U(VI) and Tc(VII), has pH values as low as 3.3, and nitrate concentrations as high as 120 mM. The objective of this research was to determine if in-situ bio-immobilization is a viable treatment alternative for this water....
A field study was conducted to determine the applicability of multivariate
geostatistical methods to the problem of estimating and simulating pesticide
concentrations in groundwater from measured concentrations of nitrate and pesticide,
when pesticide is undersampled. Prior to this study, no published attempt had been made
to apply multivariate geostatistics to...
A method was developed for assessing the vulnerability
of groundwater to contamination from contaminant sources
at the soil surface, using a numerical groundwater flow
model linked to a digital map database. The method was
applied using the pcARC/INFO Geographic Information System
(GIS) to input, store, and manipulate base maps, resulting...