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        검색결과 28

        21.
        1998.02 KCI 등재 서비스 종료(열람 제한)
        Toxic Mastoparan B(MP-B) which is purified from the venom of the hornet Vespa basalis is a cationic amphiphilic tetradecapeptide. MP-B and its Ala-substituted analogues were synthesized by solid phase method and the toxic peptide-membrane interactions were examined by circular dichroism(CD) spectra, fluorescence spectra, and leakage abilities in phospholipid membranes. In the presence of phospholipid vesicles, synthetic MP-B and its analogues formed amphiphilic α-helical structures, but in the buffer solution, those exhibited random coil conformation as measured by CD. Fluorescence spectra of MP-13 and its analogues which indicated the binding affinity of peptide on phospholipid vesicles showed that the replacement of Lys at position 2 and 11 with Ala caused a remarkable effect in the blue shift and that at position 2, in the leakage ability of the peptide.
        22.
        1997.10 KCI 등재 서비스 종료(열람 제한)
        This study was performed to investigate the riverbed structure and the pollution type in Nakdong River, Western Nakdong River, and Suyoung Stream. Sediment and water samples were collected at 15 in Nakdong River, 7 in Western Nakdong River, and 8 sites in Suyoung Stream from February 20, 1997 to June 15, 1997. The depth distributions of sampling sites in the three streams were measured and heavy metals(Cd, Pb, Cr, Cu) and pesticides in sediments and COD, BOD, and total nitrogen(T-N) in water samples were analyzed. The deepest and the shallowest sites were site 11(11.58m) and 9(3.35m) in Nakdong River, site 7(6.25m) and 4(2.06m) in Western Nakdong River, and site 8(2.89m) and 1(0.61m) in Suyoung Stream, respectively. The mean concentration of Cd(45.79ppm) was higher in the sediment of Western Nakdong River than in other two streams and those of Pb(76.25ppm), Cr(48.13ppm), and Cu(77.50ppm) were higher in the sediment of Suyoung Stream than in other two streams. Pesticides(1 kind of organophosphonis and 3 kinds of organochlorine pesticide) were detected only in the sediment of Western Nakdong River. The mean concentrations of COD(20.26ppm), BOD(25.36ppm), and T-N(18.05ppm) were higher in the water sample of Suyoung Stream than in other two streams.
        23.
        1997.10 KCI 등재 서비스 종료(열람 제한)
        This paper aims to describe the indoor-outdoor air quality in school environment through the analyses of heavy metal concentration by Inductively Coupled Plasma(ICP), which were observed at some school environment, such as traffic area, industrial area, seme-industrial area, and residence area. The results are as follows ; (1) Regardless indoor and outdoor, the area with the highest concentration of heavy metal is industrial area followed by traffic area, residence area and semi-industrial area in descending order of magnitude. And the heavy metal concentration of indoor is higher than that of outdoor. (2) The main heavy metal components with more high level concentration of indoor than those of outdoor are Zn, Al, Ca and these heavy metal concentrations are higher in class than in corridor and outdoor.
        24.
        1997.08 KCI 등재 서비스 종료(열람 제한)
        Pesticide residues were extracted with 70% acetone and transferred to dichloromethane. Extracts were applied to open-column chromatography with florisil and alumina-N. The final extract was analyzed by gas chromatography with electron-capture detector(GC/ECD) and nitrogen-phosphorus detector(GC/NPD). Recoveries of the 17 organochlorine pesticides were ranged from 60.8 to 84.9% and those of 15 organophosphate pesticides, from 70.5% to 100.0%(except phosmet and azinphos-methyl). The minimum detectable levels of this analytical method were low(0.021-0.058㎎/㎏).
        25.
        1997.06 KCI 등재 서비스 종료(열람 제한)
        A halophilic V. vulnificus is an estuarine microorganism that has been associated with fatal wound infection and life-threatening septicemia. Hemolysin is defined as toxic substance produced by various species of bacteria including V. vulnificus. Hemolysin from marine V. vulniiicus was purified and the effect of pH, temperature, metal ion on the activity of hemolysin, and thermostability of hemolysin were tested in this study. Hemolysin lysed the sheep red blood cell and the optimum pH was 8.0, the optimum temperature was 40℃, and K^+ increased but Mn^2+ decreased the hemolytic activity of hemolysin, but hemolysin was unstable to heat.
        26.
        1997.04 KCI 등재 서비스 종료(열람 제한)
        Organophosphate pesticides were extracted with 70% acetone and then transferred to dichloromethane. Extracts were applied to open-column chromatography with florisil The final extract was analyzed by gas chromatography with nitrogen-phosphorus detector(GC/NPD). Recoveries of the 18 organophosphate pesticides were ranged from 88.7% to 100.0% for the narrow-bore capillary GC(Ultra-2). The minimum detectable level of this analytical method was 0.019 - 0.035 ㎎/㎏. Sample throughput(extraction, open-column chromatography, and GC analysis) was decreased considerably (8h per sample).
        27.
        1996.12 KCI 등재 서비스 종료(열람 제한)
        Cation exchange distribution coefficients of poly(dithiocarbamate) were presented for Cd^2+, Cr^3+, and Pb^2+ in HCl. The distribution coefficients were determined by using the batch method. Based on these distribution data, the separation possibilities of the heavy metal ions were discussed. The distribution coefficients of three heavy metal ions on dithiocarbamate resin were decreased as HCl concentrations were increased. The selective separation of Cr^3+ and Cd^2+ was possible by using 0.1 M HCl in dithiocarbamate resin and the reproducibility test showed that the average absorptivity of resin was 90% in the case of Cd^2+ ion by the column method.
        28.
        1996.12 KCI 등재 서비스 종료(열람 제한)
        The sediment in the highly contaminated Gamjeon brook was collected, mixed with the raw material of the tile, and then the commercial tile was produced using the mixture. The concentrations of the heavy metals in the mixture-before and after the tile was produced-were analyzed and the effects of the acid solution on the produced file were examined. The production of the tiles was successful and the result of heavy metal analysis showed that the concentration of Fe was the highest and that of Cd was the lowest The amount of heavy metal in the sediment - the raw material of the tile mixture was more than that of the produced tile. The elution concentration of the heavy metal by the acid solution(pH = 4 - 7) was low and the quality of the produced tile was better than the commercial tile. The result of this study suggested that the contaminated sediment was removed to produce good tiles, therefore the water pollution and soil pollution were reduced.
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