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박지호 ( Ji-ho Park ),김원일 ( Won-ii Kim ) 한국산업융합학회 2005 한국산업융합학회 논문집 Vol.8 No.1
Titanium specially has high specific strength, excellent mechanical properties as fatigue strength and fracture ductility, good corrosion resistance, and therefore are broadly applied to the various fields. It is required the development for the skills of wire-cut electrical discharge machining(WEDM), but the WEDMed surface was found to be worst due to the attached components of wire. Therefore precision maching method like lapping is necessary for getting high quilty surface. Roughness of lapped surface, surface hardness to each process depth and improved method of surface shape were stuided experimentally, by changing of grain size of diamond lap material and lapping pressure with constant speed in lapping process.
고우리 ( Woo Ri Go ),김지영 ( Ji Young Kim ),류지혁 ( Ji Hyock Yoo ),이지호 ( Ji Ho Lee ),( Anitha Kunhikrishnan ),이정미 ( Jeong Mi Lee ),김계훈 ( Kye Hoon Kim ),김두호 ( Doo Ho Kim ),김원일 ( Won Ii Kim ) 한국환경농학회 2012 한국환경농학회지 Vol.31 No.3
BACKGROUND: Increase of heavy metals in agricultural ecosystem has become a social issue nationwide as it is related to public health. This study was performed to find out the status and long-term trends with consecutive application with the commercial liquid pig manure in the agricultural fields. METHODS AND RESULTS: Heavy metals including arsenic, cadmium, copper, lead, nickel, and zinc were analyzed in the 41 samples of paddy fields and 54 samples of upland fields consecutively applied with commercial liquid pig manure for 0 to 16 years, Heavy metal accumulation were not increased statistically at the both paddy and upland fields as the consecutive application year of commercial liquid pig manure were increased. However, some of surveyed upland soils exceeded the criteria of cadmium, copper, and zinc designated by the Soil Environmental Conservation Act in Korea, CONCLUSION: Therefore, analysis of heavy metals, specially copper and zinc, in agricultural fields is absolutely necessary before liquid pig manure application to the fields, In addition, heavy metal accumulation in agricultural fields following to the long-term application of liquid pig manure will be monitored periodically considering with bioavailability of copper and zinc to the crops as an essential nutrients.
정구복 ( Goo Bok Jung ),권순익 ( Soon Ik Kwon ),홍성창 ( Sung Chang Hong ),김민경 ( Min Kyeong Kim ),채미진 ( Mi Jin Chae ),김원일 ( Won Ii Kim ),이종식 ( Jong Sik Lee ),강기경 ( Kee Kyung Kang ) 한국환경농학회 2012 한국환경농학회지 Vol.31 No.2
BACKGROUND: Mine drainage from metal mining districts is a well-recognized source of environmental contamination. Oxidation of metal sulfides in mines, mine dumps and tailing impoundments produces acidic, metal-rich waters that can contaminate the local surface water and soil. METHODS AND RESULTS: This experiment was carried out to investigate the pollution assessment of heavy metal on the water quality of mine drainage, paddy soils and sediment in lower watershed affected by mine drainage of the Sambo mine. The average concentrations of dissolved Cd (0.018∼0.035 mg/L) in mine drainage discharged from the main waste rock dumps(WRD) was higher than the water quality standards (0.01 mg/L) for agricultural water in Korea. Also, the average concentrations of dissolved Zn, Fe and Mn were higher than those of recommended maximum concentrations (Zn 2.0, Fe 5.0, Mn0.2 mg/L) of trace metal in irrigation water proposed by FAO (1994). The average contents of Pb and Zn in paddy soils was higher than those of standard level for soil contamination (Pb200, Zn 300 mg/kg) in agricultural soil by Soil Environmental Conservation Act in Korea. Also, the concentrations of Cd, Pb and Zn in sediment were higher than those of standard level for soil contamination (Cd10, Pb400, Zn 600 mg/L) in waterway soil by Soil Environmental Conservation Act in Korea. The enrichment factor (EFc) of heavy metals in stream sediments were in the order as Cd>Pb>Zn>As>Cu>Cr>Ni. Also, the geoaccumulation index (Igeo) of heavy metals in stream sediments were in the order as Zn>Cd>Pb>Cu>As>Cr>Ni, specially, the geoaccumulation index (Igeo) of Zn (Igeo3.1∼6.2) were relatively higher than that of other metals in sediment. CONCLUSION(s): The results indicate that stream water and sediment were affected by mine drainage discharged from the Sambo mine at least to a distance of 1 km downstream (SN-1, SN-2) of the mine water discharge point.