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...
More efficient methods are needed for the in-situ evaluation of mass transfer parameters which describe the movement of solutes through aquifer material. The objective of this study was to develop a method for estimating diffusion rate and capacity coefficients using a single-well, "push-pull" tracer test. The method consists of the...
Opakapaka (Pristipomoides filamentosus) is a snapper (family Lutjanidae) native to the waters around Hawaii. Recent population declines of this commercially important species have increased interest in the culture of this fish. Survival of this fish through the larval period in culture has been consistently low, usually not exceeding 2%. The...
The purpose of this study was to investigate the distribution
and magnitude of scattered radiation from a typical
mobile radiographic examination as an aid in evaluating
the potential health hazards of the scattered radiation.
Also discussed are current radiation protection standards and
recommendations for mobile radiography.
A Manonite phantom represented...
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...
A pulse reader for ionization chambers has been developed,
tested, and calibrated. An insulated gate field effect transistor
(IGFET) was used to detect the pulses and Victoreen Model 362
Pocket Chambers were used as ionization chambers. The energy
dependence of the Victoreen Model 362 Pocket Chamber was determined
to be...
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...
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...
Disposal of chlorinated hydrocarbons is a major environmental concern due to the lack of a satisfactory means of safe remediation at all contaminated locations. Current technologies rely primarily on incineration, a process that can lead to dangerous byproducts such as dioxin. If the chlorine substituent can be removed prior to...