This paper discusses the advantages of stable-element tags over radioactive ones in studying complex systems outside the laboratory, and illustrates three applications. These are collaborative investigations of atmospheric transport of dust, seabed movement of sand, and long-term survival rates of freshwater fish. All use lanthanide tags, with analysis by instrumental neutron activation. The importance of a high-throughput, inexpensive analytical method is stressed.
Authors:Ihsanullah, J. Akhter, A. Rauf and M. Atta
A comprehensive radiochemical procedure for the measurement of gamma/beta activity of131I has been standarized by optimizing different steps. The procedure is mainly divided into three stages, i.e., (1) concentration
of iodine using anion exchange column followed by elution; (2) extraction of iodine into CCl4 and back extraction, and (3) precipitation as AgI. The percent chemical recovery and the lower limit of detection (LLD) were
found to be 75.5±5% and 0.014 mBq/ml, respectively.
A fully automated neutron activation analysis (NAA) facility has been constructed at the Whiteshell Nuclear Research Establishment. This high-capacity facility has been designed for use with a wide variety of neutron sources, including Canada's SLOWPOKE II and MAPLE research reactors. Its pneumatic transfer system is driven by a Square-D Model 500 programmable controller, linked in turn to a Nuclear Data ND6700 computer/spectrometer. Custom software for data entry and system control has been combined with Nuclear Data software for gamma-spectrum acquisition and processing to create a flexible, easy-to-use facility for NAA. Its design and performance are discussed.
Authors:M. Zommara, M. Hung, K. Imaizumi and M. Atta
The effect of diets containing corn, olive, roselle seed oils and ghee (pure milk fat) on growth and tissue lipid profiles of C57PL/6N mice was investigated. No diet had deleterious effect on mice growth; however milk fat significantly increased mice body weight gain. Comparing with ghee, vegetable oils reduced serum cholesterol; whereas corn oil had the superior effect. Serum of mice fed olive oil and ghee held significantly higher levels of HDL cholesterol than the other groups. Among all mice, serum total/HDL cholesterol ratio was significantly lower in corn oil group, however, the olive oil diet significantly reduced serum LDL cholesterol. The ghee group held significantly eminent serum triglycerides (TG) content. Liver cholesterol content of mice fed corn or roselle seed oil was significantly lower than that of the other groups. The weight of adipose tissue and its content of TG were comparable among all groups. The present study demonstrates for the first time the nutritional properties and beneficial effects of roselle seed oil on tissue lipid profiles using experimental animals. The obtained results may support the claim of using roselle seed oil in human nutrition.
Authors:J. Chen, E. Hildebrandt, H. Delaney, W. Boivin, E. Bialas, E. Bialas, E. Attas and M. Heinrich
Automated alpha and gamma spectrometry systems have been fabricated to analyze large numbers of samples in batches and to perform on-line analysis for a number of experiments concurrently. Specially designed sample changers for alpha and gamma spectrometry and gamma scanners for used fuel and in-situ glass leach experiments have been built. These communicate through digital interfaces, microprocessors, microcomputers and programmable controllers to a Nuclear Data model ND6700 computer/spectrometer. Application software for data entry and reports has been written to interact with Nuclear Data software to pemit easy and efficient operation.