• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2016년도 춘계학술대회
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• pp.132-134
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• 2016

The Study mainly focused on bioremediation of 16 types PAHs and heavy metals in contaminated marine sediments at filed scale study using slow release biostimulant ball (BSB) was investigated. In our experiment, filed scale study ($1m{\times}1m$) was performed and the effect of BSB on PAHs and heavy metals were analysed. BSB size and distance were determined and optimum size and distance were 3cm and 5.5cm respectively. BSB containing nutrients of acetate, nitrate and sulphate which can enhance the activity of microorganism to increase degrading capacity of PAHs and enhance the heavy metals stabilization also to decrease bioavailability. PAHs containing 16 types of 2, 3, 4, 5 and 6 rings compound PAHs were found and to degrade upto 100% in 2, 3 rings, upto 90 to 94% in 4 and 5 rings and 6 ring compound was degrade up to 70%. For heavy metals stabilization percentage was increased using BSB sediment and exchangeable portion was decreased and residual portion was increased in all analysed heavy metals. BSB enhance the PAHs degradation and stabilization of heavy metals percentages. BSB is a promising method for remediation of PAHs and heavy metals in contaminated marine sediments.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 춘계학술대회 논문집
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• pp.156-163
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• 1997

Recently, attempts have been made to be join ceramics to metals in order to make up for the brittleness of ceramics. The difference in the coefficients of linear expansion of the two materials joined at high temperature will cause residual stress, which has a strong influence on the strength of the bonded joints. In this paper, the residual stress distribution and stress intensity factors of the ceramic/metal bonded joints were analyzed by 2-dimensional elastic boundary element method. Fracture toughness tests of ceramic/metal bonded joints with an interface crack were carried out. So the advanced method of quantitative strength evaluation for ceramic/metal bonded joints is to be suggested. Fracture surface and crack propagation path were observed using scanning electron microscope.

• Journal of Welding and Joining
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• 제29권4호
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• pp.73-79
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• 2011

Friction stir welding (FSW) is a solid state joining method patented in 1991 by The Welding Institute (TWI). It is widely used for joining light metals such as Al and Mg alloys. Foreign railway vehicle manufacturing companies have been applying FSW to car body welding, but domestic companies are in the beginning of feasibility study. Therefore, lots of experimental and analytical study is needed. In this study, three-dimensional finite element modeling of the friction stir welding of two Al6061-T6 plates was carried out. And temperature field and residual stresses were obtained and compared to experimental results in the literature. It is found the analytic thermal field is in a good agreement with the experimental results, but there are some differences between numerical and experimental residual stresses.

• 대한환경공학회지
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• 제36권1호
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• pp.67-73
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• 2014

본 연구에서는 토양세척기법으로 1차 처리한 광미에 제거되지 않고 남아있는 중금속을 인산염을 이용해서 안정화하였다. 광미에 잔류하는 오염물질 농도는 As (1,861 mg/kg), Cd (20 mg/kg), Cu (56 mg/kg), Pb (2,149 mg/kg), Zn (633 mg/kg)이었다. 안정화제로는 $CaHPO_4$, $Ca(H_2PO_4)_2{\cdot}H_2O$, hydroxyapatite를 사용하였고, 안정화제의 첨가량은 0.1 wt%, 1 wt%, 10 wt%, 안정화 기간은 1, 3, 5, 7, 14일로 조절하였다. 세 가지 안정화제 모두 효율이 높았지만, 그 중에서 $Ca(H_2PO_4)_2{\cdot}H_2O$의 효율이 가장 높았고 첨가량은 1 wt%가 적당했다. 안정화 기간에 따른 효율차이는 크지 않았다. 1 wt% $Ca(H_2PO_4)_2{\cdot}H_2O$를 사용해서 1일 동안 안정화처리를 한 경우, TCLP 용출액의 비소와 중금속 농도는 As (0.328 mg/L), Cd (0.250 mg/L), Cu (0.143 mg/L), Pb (0.359 mg/L), Zn (2.622 mg/L)로 모두 각각의 RCRA-TCLP 기준치 이하로 나타나 안정성이 있는 것으로 평가되었다.

• 한국버섯학회지
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• 제19권4호
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• pp.294-299
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• 2021

본 연구를 통해 국내 주요 한약재인 복령의 유해물질에 대한 안전성 확립과 허용기준치 설정의 기초자료를 제공하고자 한다. 국내 유통 중인 복령 10건(국내산 5건, 중국산 5건)에 대한 잔류농약(321종), 중금속(7종), 방사능(3종), 회분 함량을 분석하였다. 잔류농약은 국내산 1건에서만 농약 성분인 cypermethrin 0.03 mg/kg이 검출되었으나 기준치 이하로 나타났다. cypermethrin은 과수 및 원예농업에서 해충 방제의 살충제로 사용되는 성분이다. 중금속은 Hg를 제외한 Zn, Pb, Ni, Cu, Hg, Cr가 모든 시료에서 검출됐지만 기준치 이하로 나타났다. Cd는 중국산 1건에서 0.011 mg/kg이 검출되었다. 방사능 농도도 모든 시료에서 MDA값 이하로 나타나 불검출 수준이었으며, 회분 함량도 모든 시료에서 기준치인 1.0% 이하로 나타났다. 이번 조사에서 국내에 유통 중인 복령의 유해물질에 대한 위해성은 안전하게 나타났다. 일반적으로 버섯류는 중금속 함량이 높다고 알려져 있다. 복령은 토양 속에서 생장하는 재배 특성상 유해물질에 항시 노출되어 있으므로 재배, 저장, 유통 등 생산단계 전반에 대한 지속적인 모니터링과 체계적인 관리기준 설정이 필요할 것으로 보인다.

• 대한본초학회지
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• 제23권4호
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• pp.51-58
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• 2008

Objectives: To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after a decoction. Methods: The heavy metal contents before/after a decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometer(ICP-AES) and mercury analyzer. In order to analyze pesticides in 5 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide($SO_2$) were performed by Monier-Williams distillation method. Results: 1. The mean values of heavy metal contents(mg/kg) for the samples were as follows: Galgeun-tang(before decoction-Pb; 0.793, Cd; 0.133, As; 0.016 and Hg; 0.005, after decoction-Pb; 0.033, Cd; 0.004, As; 0.002 and Hg; not detected), Gumiganghwal-tang(before decoction-Pb; 0.934, Cd; 0.197, As; 0.046 and Hg; 0.006, after decoction-Pb; 0.062, Cd; 0.007, As; 0.004 and Hg; 0.0001), Sosiho-tang(before decoction-Pb; 0.891, Cd; 0.134, As; 0.091 and Hg; 0.014, after decoction-Pb; 0.036, Cd; 0.002, As; 0.004 and Hg; not detected), Ojuck-san(before decoction-Pb; 0.907, Cd; 0.136, As; 0.084 and Hg; 0.007, after decoction-Pb; 0.074, Cd; 0.007, As; 0.011 and Hg; 0.0005) and Samsoeum(before decoction-Pb; 1.234, Cd; 0.154, As; 0.016 and Hg; 0.007, after decoction-Pb; 0.094, Cd; 0.006, As; 0.002 and Hg; 0.001). 2. Contents(mg/kg) of residual pesticides before/after a decoction in all samples were not detected. 3. Contents(mg/kg) of sulfur dioxide($SO_2$) before a decoction in Galgeun-tang, Gumiganghwal-tang, Sosiho-tang, Ojuck-san and Samsoeum exhibited 1.2, 3.4, 11.1, 12.0 and 5.7, respectively. However, contents of sulfur dioxide after a decoction in all samples were not detected. Conclusions: These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• 대한한의학회지
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• 제30권4호
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• pp.108-117
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• 2009

Objective: To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after a decoction. Methods: The heavy metal contents before/after a decoction were measured by inductively-coupled plasma atomic emission spectrometer (ICP-AES) and mercury analyzer. In order to analyze pesticides in 5 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide ($SO_2$) were performed by Monier-Williams distillation method. Results: 1. The mean values of heavy metal contents (mg/kg) for the samples were as follows: Sipjeondaebo-tang (before decoction - Pb; 1.163, Cd; 0.257, As; 0.080 and Hg; 0.016, after decoction - Pb; 0.059, Cd; 0.007, As; 0.006 and Hg; 0.0003), Palmul-tang (before decoction - Pb; 1.181, Cd; 0.242, As; 0.152 and Hg; 0.014, after decoction - Pb; 0.067, Cd; 0.008, As; 0.008 and Hg; 0.0003), Sagunja-tang (before decoction - Pb; 1.285, Cd; 0.283, As; 0.063 and Hg; 0.012, after decoction - Pb; 0.047, Cd; 0.009, As; 0.004 and Hg; not detected) and Samul-tang (before decoction - Pb; 1.025, Cd; 0.169, As; 0.099 and Hg; 0.013, after decoction - Pb; 0.065, Cd; 0.007, As; 0.010 and Hg; 0.001). 2. Contents (mg/kg) of residual pesticides before/after a decoction were not detected in any samples. 3. Contents (mg/kg) of sulfur dioxide ($SO_2$) before a decoction in Sipjeondaebo-tang, Palmul-tang, Sagunja-tang and Samul-tang exhibited 5.0, 6.0, 14.0 and 6.9, respectively. However, contents of sulfur dioxide after a decoction were not detected in any samples. Conclusion: These results will be used to establish a criterion for heavy metals, residual pesticides and sulfur dioxide.

• 사상체질의학회지
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• 제21권1호
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• pp.237-246
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• 2009

1. Objectives To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after decoction. 2. Methods The heavy metal contents before/after decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and mercury analyzer. In order to analyze pesticides in 3 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide (SO2) were performed by Monier-Williams distillation method. 3. Results 1) The mean values of heavy metal contents (mg/kg) for the samples were as follows: Yuldahanso-tang (before decoction - Pb; 1.85, Cd; 0.148, As; 0.042 and Hg; 0.003, after decoction - Pb; 0.096, Cd; 0.006, As; 0.006 and Hg; 0.002), Chongsimyonja-tang (before decoction - Pb; 1.193, Cd; 0.094, As; 0.084 and Hg; 0.008, after decoction - Pb; 0.053, Cd; 0.007, As; 0.011 and Hg; not detected) and Taeyeumjowee-tang (before decoction - Pb; 0.878, Cd; 0.078, As; 0.302 and Hg; 0.004, after decoction - Pb; 0.079, Cd; 0.005, As; 0.006 and Hg; not dectcted). 2) Contents (mg/kg) of residual pesticides before/after decoction in all samples were not detected. 3) Contents (mg/kg) of sulfur dioxide (SO2) before decoction in Yuldahanso-tang, Chongsimyonja-tang and Taeyeumjowee-tang exhibited 6.1, 37.8, 31.5 and 19.7, respectively. However, contents of sulfur dioxide after decoction in all samples were not detected. 4. Conclusion These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• 한국습지학회지
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• 제14권3호
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• pp.365-374
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• 2012

양돈 농가에서 구리, 아연 등의 성장촉진제와 항생제들이 사료 첨가제로 사용되는데 사료에 주입된 많은양이 분뇨로 배설되고 있다. 국내 양돈 폐수의 90% 이상이 퇴, 액비 형태로 농지에 적용되고 있는 상황에서 퇴,액비 내에 함유된 중금속과 항생물질은 토양에 흡착되어 농지에 잔류하거나 지하수나 지표수로 유출되어 수계로 빠져나간다. 농지에 살포된 중금속과 항생물질의 토양 내에서의 거동을 살펴보기 위해 실험실 기초 실험을 수행하였는데, Jar test와 칼럼 용출 실험을 수행하였다. 실험결과 아연의 86.4와 구리의 68%가 토양에 흡착되는 것으로 나타난 반면, 액비에 포함된 항생물질의 60% 이상은 칼럼 유출수로 용출되는 것으로 나타났다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권4호
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• pp.39-45
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• 2010

In order to treat paddy soils contaminated by Pb, Cd, and As near the abandoned mine, $H_2PO_4$ was used for stabilization of Pb ($PO_4$/Pb mole ratio of 2/1). In addition, $CaCO_3$ and $FeSO_4$ were used as stabilizers for treating Cd and As (2% w/w), respectively. Leaching tests were conducted with artificial rain in the column to assess the heavy metal stabilization efficiency. The mass of heavy metals in the effluents passed through the columns were analyzed. The remaining heavy metals in the soils were also analyzed as Korean soil standard method, phytoavailability test and sequential extraction test. Lead in the effluent was not detected when $H_2PO_4$ was used as a stabilizer. This result suggests that $H_2PO_4$ is efficient for Pb stabilization. In addition results of sequential extraction scheme suggest that heavy metals are present as residual forms which is not easily extracted.