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姜榮浩,金道聖,高在杰 慶北大學校 1981 論文集 Vol.32 No.-
Charged particles create their tracks in most dielectric solids. These tracks can be viewed under optical microscope after proper chemical etching. Tracks of uranium fission fragments in obsidians also can be viewed after etching by HF solution and used for age dating. In this paper, dating formula and experimental procedures for fission track dating are introduced. And spontaneous and induced fission tracks by thermal neutrons are counted under optical microscope (magnification of 400x). Measured fission track ages of obsidian samples, OM No. 147 and HM No. 40 are 8.86 x 10 exp (5)y and 7.67 x 10 exp(5)y, respectively.
姜榮浩 慶北大學校 1958 論文集 Vol.2 No.-
We are under the influence of natural radioactivity and artificial radioactivity caused by the experimets with atomic and hydrogen bombs. Among those radioactive isotopes are Sr 90 and Ce 144 which have been proved to be critically harmful to human bodies. Since such radioactive substances are being accumulated in the atmosphere and soil, the measurement of their intensity at present will be of considerable importance in order to make comparison with future data. This experiment was done with subsurface water, rain water, edible vegetables and some other plants available, and the results were as follows; (1) There have no great influence on mean value of background. (2) Mean value for subsurface water were very small compared to that for rain water. (3) By Table 12. it clear that isotopes in rain water have long half lives. According to the Nuclear Decay Chart (General Electric Co. USA 1956). Those isotopes were seemed to be Sb^126(28d), Cr^51(27d), Cm^24(27d), Pa^233(27.4d), Nb^95(35d), Cm^241(35d) and W^185(74d), but chemical analysis for those isotopes were not done yet that it remains to be determined whether rain water actually contains the above mentioned isotopes or not. (4) The wild edible vegetables, in general, are more radioactive than cultivated vegetables. (5) It may be that the geometrical differences of plants have a great influence on the degree of contamination; i.e. plants with big leaves with hairs are more severely contaminated than plants with small leaves and fragile stems.