[en] A statistical procedure is presented that can be used to estimate the number of Working Level (WL) measurements that are required to calculate the average WL to any required precision, at given confidence levels. The procedure assumes that the WL measurements have a normal distribution. WL measurement from Canadian Uranium mines are used to illustrate a procedure of insuring that estimated Working Level Months can be calculated to the required precision. An addendum reports the results of tests of normality of the WL data using the W-test and the Kolmagornov-Smirnov test. (author)

[en] Topics presented include integrating neural networks and expert systems, neural networks and signal processing, machine learning, cognition and avionics applications, artificial intelligence and man-machine interface issues, real time expert systems, artificial intelligence, and engineering applications. Also considered are advanced problem solving techniques, combinational optimization for scheduling and resource control, data fusion/sensor fusion, back propagation with momentum, shared weights and recurrency, automatic target recognition, cybernetics, optical neural networks

No abstract available

[en] The differential equations governing the flow of iodine through a three-compartment model of iodine metabolism in man have been solved and the solutions compared to those obtained from two-compartment models. The boundary conditions used were those appropriate for a single acute exposure to radioiodine. The urinary excretion equation derived from the solutions to the three-compartment model exhibits a minimum at four days after the exposure time. This minimum can be used to calculate a maximum value for thyroid burden using a single urinary excretion rate measurement, and in conjunction with this value, an optimum urinary sampling frequency for the different radioiodines can be calculated. (author)

[en] Following the discovery of a ¹⁴C-bearing aerosol during the re-tubing of a CANDU reactor, a procedure was developed to monitor workers for inhaled ¹⁴C by measuring the amount of ¹⁴C excreted in feces. This procedure requires that an appropriate lung model be used to give the relationship between the fecal excretion and ¹⁴C in lung and possibly other tissues. Since preliminary studies on samples from air filters indicated that that the ¹⁴C aerosol was insoluble, it was decided to use the International Commission on Radiological Protection's (ICRP) lung model for insoluble material, commonly called Class Y (ICRP 1966; ICRP 1979). In order to ensure that the selection of the ICRP Class Y lung model was appropriate for this aerosol, an experiment was carried out to measure the rate that ¹⁴C was cleared from the deep lung to the GI tract and then excreted in feces, and the rate that ¹⁴C was solubilized and transferred to liver or excreted in urine in the rat. Liver and urinary excretion were chosen because it was assumed that any ¹⁴C transferred to blood would be in an unknown organic form, and hence taken up the liver, or would be as HCO₃^-/CO₂ . It is expected that both of these possibilities would result in ¹⁴C in urea in the urine (Orten and Neuhaus 1986). Extrapolations to humans can be made by comparison of the ¹⁴C results to those for a ¹⁴¹CeO₂ control exposure carried out at the same time. The CeO₂ was selected as the control exposure material as it was readily available and had been used by other laboratories (e.g., Lundgren et al. 1980). Its retention and excretion is consistent with that described by the ICRP Class Y model. Hence, if the ¹⁴C aerosol had a retention and excretion pattern similar to CeO₂, its retention and excretion would also be reasonably described by the Class Y model. This note summarizes the results of this experiment. (author)

[en] Over the past few years there has been intense experimental activity focused on measuring the spin-dependent structure functions of the proton and neutron, triggered by results reported in 1987 by EMC that implied only a relatively small fraction of the proton spin is due to the spins of the constituent quarks. Recent experiments have been performed with longitudinally polarized beams of electrons (at SLAC) or muons (at CERN) incident on longitudinally or transversely polarized nucleon targets, and have yielded substantial improvements in the experimental errors on the measurements. The latest results from these experiments will be reviewed and compared with predictions of the Bjorken sum rule, the Ellis-Jaffe sum rules, and expectations of the naive quark model. Prospects for the future will be discussed

[en] Four methods of estimating Working Levels with ''Instant Working Level Meters'' are reviewed. The accuracy and precision of these methods are evaluated for the range of concentrations of the short-lived daughters of ²²²Rn that exist in mining atmospheres. Included is a comparison of the overall uncertainty in the Working Level as measured using these methods with that measured with the more commonly used Kusnetz method. (author)

No abstract available

[en] Annual limits on intake and derived air concentrations are calculated for the radioiodines with mass numbers 123 to 135 using a currently accepted model of iodine metabolism in man and values for reference man. Results are also given for thyroid burdens and urinary excretion rates as functions of time for three exposure patterns. (author)

[en] The detectors, electronics and shielding used at Chalk River Nuclear Laboratories to measure in vivo radioactive isotopes, whose only emissions capable of penetrating to the outside of the body are low energy photons, are described. Also described are the methods used to calibrate these detectors, and electronic components, and the uncertainties associated with these calibrations, for the transuranic isotopes ²³⁸Pu, ²³⁹Pu, ²⁴⁰Pu, and ²⁴¹Am. (author)