The biodegradation of five polychlorinated biphenyls (PCBs) by
Hudson River and Silver Lake sediments was studied using gas
chromatography with electron capture detection (GC/ECD) and gas
chromatography with mass spectrometry (GC/MS) analyses. Methanogenic
sediments from the Hudson River and Silver Lake were used to inoculate
four anaerobic filter reactors. The...
The effects of vertical ground motion are particularly significant
in the design of highway bridge girders. Conventional codes do
not recommend methods for solving the problem. The intent of this
work is to suggest an approach for such design.
A set of curves for velocity spectra which are the average...
As mass-timber building construction rises around the globe, there exists the need to verify the long-term, in-situ behavior and performance of these structural systems. Structural health monitoring (SHM), generally defined as a damage detection strategy consisting of a network of sensors, a data acquisition system, and algorithms for data analysis,...
A problem confronting the Corps of Engineers and other water resources planners in the Pacific Northwest is the prediction of anadromous fish enhancement benefits that would result from a proposed high dam project. These benefits are expected from augmenting natural streamflows with relatively cold reservoir withdrawals. The resulting increased streamflows...
A spreadsheet-based transport model was developed in Microsoft Excel™ as part of a six-year National Cooperative Highway Research Program project conducted at Oregon State University. The model simulated the leaching, transport, removal, and retardation processes that occur in the surface and subsurface pathways of the near highway environment. For all...
The environment has been exposed to a number of hazardous chlorinated
organic compounds. These compounds may be anaerobically biotransformed by
sequential reductive dechlorination reactions in which the chlorine atoms are
replaced with hydrogen atoms. Because reductive dechlorination processes may
occur very slowly in the environment and chlorine position affects the...
The concept of placing high strength linear reinforcements in a
soil backfill to produce a vertical retaining structure is a recent idea
that has been applied with success at a number of locations. Rational
procedures have been developed for the design of these structures
when the reinforcements consist of long...
Unmanned aircraft systems (UAS), also known as drones, are an increasingly popular method of collecting surveying and mapping data. Two common drone-based mapping techniques are lidar and structure from motion (SfM) photogrammetry, and a frequently-heard (yet nearly impossible to answer) question is: “which is better?” The most common metric for...
Bio-cementation is a promising method for the liquefiable mitigation of loose saturated sands. In the improvement process a bacterium that can be found naturally in soil deposits is fed urea. The bacterium consumes and breaks down the urea to form ammonium and carbonate. In the presence of calcium, calcium carbonate...
This thesis presents a novel approach for propagation of uncertainty in river systems. Errors in data observations and predictions (e.g., stream inflows), in model parameters, and resulting from the discretization of continuous systems, all point to the need to accurately quantify the amount of uncertainty carried through the modeling process....
Salt-encrusted flats, or Sabkha, are common in arid and semi-arid regions worldwide, including coastal and inland areas. Due to their low shear strength and high compressibility, these soils are often unsuitable for supporting infrastructure or structures. The unique salt content of sabkha formations sets them apart from other soil types....
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...
In this study, a coupled potential flow-viscous flow model is used for numerical wave tank simulation. The solver satisfies all the requirements for such a simulation environment. The coupling scheme is based on a non-overlapping heterogeneous domain decomposition method. In this method, the flow domain consists of two subdomains. In...
The combination of increased training tempo due to military base closures and the reduction in military budgets have placed a severe burden on the infrastructure at many military installations and emphasized the need for an integrated facility management support system. This research involved linking existing facility, environmental, and operational data...
Metal-plate-connected (MPC) trusses have traditionally been designed based on a
tributary load distribution and a simplified truss model. This design method ignores the
load-sharing and composite action in MPC roof truss systems, the semi-rigidity of MPC
joints, and joint eccentricity.
The main objective of this study was to provide a...
This study presents a practical method to model an actual Metal-Plate-
Connected (MPC) roof truss assembly using a commercial program, SAP2000, to
investigate its system performance. Truss assembly modeling was examined
because the conventional single truss design method ignores system effects, such as
variability of modulus of elasticity (MOE), interaction...
Recent concern over the potential environmental impact of highway construction
and repair materials on surface and ground waters has lead to extensive laboratory
screening and subsequent testing of a set of new materials and waste amended mixes. As
part of Phase II of a three-phase project for the National Cooperative...
In recent decades, the occurrence of large, high severity wildfires has increased substantially in many parts of the world, including the western United States. These fires have the potential to impact water quality, aquatic ecosystems, and downstream communities for many decades. As such, it is increasingly important to understand the...