This study examines stream channel erosion processes in a small urbanizing watershed influenced by deposits of the Columbia Basin catastrophic floods: Kelley Creek, a 12-km² tributary of Johnson Creek, located just east of Portland, Oregon. Information on landscape history, stream channels, and sediment dynamics was compiled. The effects of future...
High-altitude color infrared photography is found to be
an effective tool for forest inventory in the Umpqua National Forest
of southwestern Oregon. Intelligent resource management requires
the rapid, accurate, and economical inventory results that can be
supplied by remote sensing. Color infrared film is shown to possess
properties that make...
Bees play a crucial role in pollinating crops, supporting biodiversity, and maintaining ecosystem health. Despite their importance, the decline in bee populations has become a global concern due to various factors including habitat loss, urbanization, and climate change. The purpose of this thesis is to write an article that highlights...
Juniper is a native species to Oregon and confers ecological benefits to wildlife when it is at savannah and transitional densities. Its range and extent have fluctuated with climatic change, but the current range expansion is unprecedented in its extent. The range expansion has been associated with the degradation of...
Irrigated agriculture constitutes the greatest consumptive water use globally, so that irrigation efficiency measures are an important part of global efforts to best utilize this limited resource. However, greater irrigation efficiency must be achieved while simultaneously maintaining or increasing crop yields and farming profitability. Incremental water use decisions are made...
An ionization chamber was constructed, using a fiberglass wall
sphere, for the purpose of measuring background radiation. The
system consists of the fiberglass wall chamber, 38.85 liters in
volume, air filled, not sealed, used in conjunction with a precision
capacitor, nulling voltage supply and electrometer. It was calibrated
against a...
A low-energy, low-exposure-rate, guarded-field ionization
chamber system with a sensitive volume of approximately 1040 cm³ and an exposure-rate range from 60 mR/h to less than 0.5 mR/h
was designed, constructed and calibrated. The calibration was
effected by constructing and calibrating a 60 cm³ volume transfer
chamber of similar design against...
The relationship of x-ray tube housing temperature to duty
cycle was studied for a superficial therapy x-ray installation, a
dental radiographic installation, and a rotating-anode medical diagnostic
installation. Thermistors were used to measure the tube
housing temperature at points selected to be representative of
thermal conditions on the surface of...
The objective of this study was to determine the distribution of
leakage radiation from two unshielded diagnostic-type X-ray tube
housings. This information was used to determine the shielding required
in the housings to bring them into compliance with the definition
of a diagnostic-type protective tube housing, as set forth by...