A study of the precision attainable by two methods of -ray photopeak computation has been carried out. The total peak area method (TPA) and the proposed new method have been compared. The method offered is digital and simulates repeatedly accumulations of -ray spectra. The method described here computes the apparent net peak area without a clear distinction between peak and non-peak related channels. The proposed method is considered to be the most advantageous because of its relatively high precision.
Authors:M. Czauderna, A. Pepłowski, and S. Smoliński
The yeast cells, Saccharomyces cerevisiae, were exposed to Hg2+ ions (10–4M) and SeO2 (2·10–4–10–2M) or Se- methionine (2·10–4M). Instrumental neutron activation analysis (INAA) was used to analyze changes in the Hg, Zn, Fe and Co levels in these cells. When the yeast was incubated in a medium containing 10–3M and 10–2M SeO2, the Hg content of the yeast markedly increased. It was also found that the uptake of Se and Hg influenced the levels of Zn, Fe and Co found in the cells. While the presence of Se-methionine (Se-Met), SeO2 or Hg2+ ions caused increases in the intracellular Zn levels, the combined presence of Hg2+ and SeO2 and their assumed interaction, reduced the efficiency of Se for increasing the Zn content of yeast.