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        검색결과 94

        82.
        2005.06 KCI 등재 서비스 종료(열람 제한)
        It has been well known that soil erosion and sediments from alpine agricultural fields are causing severe water quality and turbidity problems in receiving waters. Also these result in the loss of money because farmers have to buy top soils to provide enough root zone in the following year. Thus, there have been needs to reduce soil erosion and sediment discharge into the stream networks. To accomplish this end, an effective erosion control plans should be developed based on scientific research, not by rule of thumb. The Universal Soil Loss Equation (USLE) has been widely used to estimate the soil erosion in many countries over the years. In this study, the USLE was used to estimate soil erosion potential under different cropping scenarios in HongCheon County, Kangwon. The soil erosion potential for continuous corn cropping was the highest compared with those from continuous potato find average cropping scenarios. This indicates the soil erosion plans need to be established considering cropping system in the field. The Unit Stream Power Erosion-Deposition (USPED) was applied for HongCheon County to estimate soil erosion and deposition areas. The USPED estimated results can be used to complement USLE results in developing effective erosion control plans.
        86.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        To obtain the residual organochlorine pesticides in the coastal environment, the methods of analysis for BHC's isomer, Kelthane, Orthocide and Endrin by GC-ECD are surveyed. The relative retention time for α-BHC, β-BHC, γ-BHC and δ-BHC is 1.00, 1.18, 1.24, 1.31 and it's of Kelthane, Orthocide, Endrin is 1.56, 1.70, and 2.02, respectively. The BHC isomers, Kelthane, Orthocide and Endrin are separated on the base line. The plate height(H) for α-BHC, β-BHC, γ-BHC and δ-BHC is 50mm, 35mm, 32mm and 29mm, and it's of Kelthane, Orthocide, Endrin is 81mm, 68mm and 48mm, respectively. The qualified defection concentration for α-BHC, β-BHC, γ-BHC and δ-BHC is 0.26, 0.36, 0.37 and 0.39ng/g and it's of Kelthane, Orthocide, Endrin is 0.55, 1.39 and 0.56ng/g, respectively. BHC's isomer, Kelthane, Orthocide and Endrin are not detected in soil environment on South Cheju Island. Also residual organochlorine pesticides are not detected in the sea water and sediment in the ocean environment.
        91.
        1997.02 KCI 등재 서비스 종료(열람 제한)
        In investigating heavy metal contents at specific areas, the method of selecting sampling points is important. A general method is, according to the law , random sampling of zigzag-form in the selected field. In this work, we studied whether the measured values obtained from a certain method of selecting sampling points is a representative of heavy metal contents in the selected field or not. The selected field for this study is located on the lower Yangsan-river; Gasan-li, Mulgum-myon, Yangsan-gun, KyoungNam. 1 km away from the main stream of Nakdong river. The heavy metals investigated were Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. The inductively coupled plasma(ICP) atomic emission spectrometer was used to measure these metals quantitatively. The number of total sampling points were 24. We compared the total mean values with the mean obtained from various methods of selecting sampling points.
        93.
        1995.08 KCI 등재 서비스 종료(열람 제한)
        PCBs have been measured using GC-ECD, GC-MS, GC-ELCD, HPLC, TLC, NMR and Immunoassay. The analysis of PCBs using GC- ECD include the peak pattern method as none derivatization and the perchlorination method as derivatization. This study was conducted to establish the perchlorination method with SbCl_5 from PCBs to decachlorinated biphenyl(DCB). The aroclor 1242 of PCBs was chlorinated and then, converted into the DCB which showed a single peak in GC-ECD chromatogram. The detection limit of DCB was 2pg. The quantification detection concentration of PCBs extracted with soxhlet was 0.5ng/g in the soil. PCBs were not detected in the suburban soil, but 174ng/g in the soil of industrial complex. Mean PCBs concentration of Shinchun stream at Kumho river and Jinchun stream at Nakdong river was calculated average 88ng/g in the sediment. PCBs concentration in the sediment of Kumho river near 2-7㎞ from conjunction with Nakdong river was average 154ng/g. PCBs concentration in the sediment of Nakdong river near conjunction with Kumho river was average 159ng/g.
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