• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.625-635
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• 1990

The purpose of this study was focused on investigation of biochemical properties of amylases in germinating corn(Zea mays L.) the amylase(I), (II) and (III) from germinating corn seeds were partially purified by ammonium sulfate precipitation, DEAE-Sephadex A-50 ion exchange column chromatography and Sephadex G-100 gel filtration. The last step was effective for separation of the corn amylases to a homogeneous slate. the purified amylase(I) was identified as a kind of $\alpha$-amylase from the fact that 5％ starch solution was hydrolysed into mainly maltose and maltotetrose by it, and amylase(II) and amylase(III) were enzymes producing maltotetrose as main product. The molecular weight and specific activity of the amylase(I), (II) and (III) were determined to be 54,000 and 70.47 unit/mg, 39,000 and 62.98 unit/mg, and 51,000 and 80.39 unit/mg, respectively. It showed a tendency to increase the amylases activities in presence of Ba, Ca, Co and Fe groups, but inhibits in that of Ag, Sn, Hg and Zn groups, and amylase(I), (II) and (III) remained stable at pH 5-6 and 2$0^{\circ}C$ for 40 days in containing of 1 mM CaCl$_2$. The optimum pH and optimum temperatures were pH 6, pH 5 and pH 6 and 35$^{\circ}C$, 55$^{\circ}C$ and 55$^{\circ}C$, respectively. These results suggest that the amylase(I), (II) and (III) were different amylases.

• Economic and Environmental Geology
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• v.22 no.1
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• pp.35-63
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• 1989

Geochemical characteristics of the Guryongsan (Ogcheon) uraniferous black slate show that this is an analogue to the conventional Chattanooga and Alum shales in occurrences. Whereas, its highest enrichment ratio in metals including uranium, among others, is explained by the cyclic sedimentation of the black muds and quartz-rich silts, and the uniform depositional condition with some what higher pH condition compared to the conditions of the known occurrences. The cyclic sedimentation, caused by the periodic open and close of the silled basin, has brought about the flush-out) of the uranium depleted water and the recharge with the new metal-rich sea water, which consequently contributed to the high concentration of metals in mud. The metal-rich marine black muds, which mostly occur in the early to middle Palaeozoic times, is attributed by the geologic conditions which related to the atmospheric oxygen contents, and these are scarcely met in the late Precambrian and/or with the onset of Palaeozoic era in the geologic evolution of the earth.