• KSBB Journal
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• 제16권1호
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• pp.54-60
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• 2001

저품위 광석으로부터 유가 금속을 회수하기 위한 생물용출법의 적용에 있어 미생물의 활성은 매우 중요하며, 제련미생물은 금속이온에 대해 어느 정도 내성을 가지고 있어야 한다. 본 연구에서는 대표적인 제련미생물인 Thiobacillus ferrooxidans의 철산화속도에 미치는 단독 혹은 혼합 금속이온의 영향을 조사하여, T. ferrooxidans의 금속이온에 대한 내성 특성을 조사하였다. 생장 배지에 $Zn^{2+}$, $Cu^{2+}$, $Ni^{2+}$, 및 $Cd^{2+}$를 단독으로 첨가한 경우(첨가농도범위, $Zn^{2+}$ 60g/L이하, $Cu^{2+}$, $Ni^{2+}$, 및 $Cd^{2+}$ 6 g/L 이하)에는 T. ferrooxidans에 의한 철산화속도는 금속이온의 첨가량에 크게 저해 받지 않았다. $Zn^{2+}$를 제외한 $Cu^{2+}$, $Ni^{2+}$, 및 $Cd^{2+}$의 2 성분 혹은 3 성분의 혼합금속이온을 첨가한 경우에는 T. ferrooxidans의 철산화 활성에 대한 혼합 금속이온의 저해 효과는 최대 50% 정도로 크게 나타나지는 않았다. 그러나, $Zn^{2+}$을 타 금속이온과 2 성분 혹은 3 성분을 혼합하여 생장 배지에 첨가한 경우에는 T. ferrooxidans의 철산화 활성 저해에 대한 혼합 금속이온의 상승 효과가 큰 것을 밝혔다.

• 한국환경과학회지
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• 제28권1호
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• pp.99-106
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• 2019

Arsenic is among the heavy metals commonly found in aqueous environments. Iron oxide is known as an efficient adsorbent for the arsenic. A new synthetic method was applied to provide iron oxide giving a large specific surface area. The mixing method affects the formation of iron oxide. Ultrasonic waves assisted the formation of very fine iron oxide in an organic phase. The synthesized iron oxide is amorphous type with a high surface area of more than $181.3m^2/g$. Sorption capacity of the synthesized adsorbent was relatively very high for arsenic and varied depending on the oxidation state of arsenic: a higher capacity was obtained with As(V). Lower solution pH provided a higher sorption capacity for As(V). The competitive effect of co-exist anions such as chloride, nitrate, and sulfate was minimal in sorption capacity of the iron oxide for arsenic.

• 보존과학연구
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• 통권31호
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• pp.173-202
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• 2010

Within the framework of the Mongolian-Korean Joint Project for "Research and Preservation of Cultural Heritage", I enrolled in 3 months training course from February to May 2010 at the Metal laboratory of Conservation Science Division in National Research Institute of Cultural Heritage, Korea. Some metal artifacts, which are preserved in Institute of Archaeology, Mongolian Academy of Sciences, were brought and restored there. These chosen findings were found at Gobi and mountainous region of Mongolia, preserved under the different circumstances and dated back to Middle Age from Bronze Age. At the Metal laboratory of the NRICH, the conservation work was carried out for three months on 15 metal objects, including arrowhead, stirrup, caltrop, axe, knife, ring and so on, which were found at Khugshin Teel's ruin of Khairkhandulaan soum of Uvurkhangai province, Ungut of Altanbulag soum of Tuv province, Baruun Naran and Ukhaa khudag of Khankhongor and Tsogttsetsii soums of Umnugobi province. The report of the result of this conservation work is available here.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.335-338
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• 2001

With the use of the electron microscopy and X-ray phase analysis the regularities of carbon deposit formation in process of methane and propane pyrolysis on the zeolites, Kazakhstan natural clays, chrome and bauxite sludge containing metal oxides of iron subgroup, have been studied. In process of over-carbonization the trivalent iron was reduced to metal form. In addition, the carbon tubes of divers morphology had been impregnated with ultra-dispersed metal particles. The kinetic parameters of carbon formation in process of methane decomposition on the zeolite CoO mixture surface were investigated by method of thermo-gravimetric analysis. The morphology and structure of formed carbon fibrils, with the metal particles fixed at their ends, have been investigated, the formation of branched carbon fibrils pattern, so called octopus, being found.

• 열처리공학회지
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• 제10권3호
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• pp.159-164
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• 1997

Non-alloyed and 1.0%Ni alloyed ductile cast iron were cast into the sand mold and metal mold, and finer graphite size was obtained in case of metal mold casting. Direct tempering after casting showed the slight increase of absorbed energy, which is largely due to the relieving of residual stress that is developed during casting. After austempering heat treatment, higher impact energy was obtained in case of metal mold casting than sand mold casting, which is due to the finer graphite size.

• Corrosion Science and Technology
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• 제7권2호
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• pp.134-137
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• 2008

Cold arc welding of cast iron has been widely used with repair welding of metal structures. However its welding is often resulted in the galvanic corrosion between weld metal zone and heat affected zone(HAZ) due to increasing of hardness. In this study, corrosion properties such as hardness, corrosion potential, surface microstructures, and variation of corrosion current density of welding zone with parameters of used electrodes for cast iron welding were investigated with an electrochemical evaluation. Hardness of HAZ showed the highest value compared to other welding zone regardless of kinds of used electrodes for cast iron welding. And its corrosion potential was also shifted to more negative direction than other welding zone. In addition, corrosion current density of WM in polarization curves was qualitatively smaller than that of HAZ. Therefore galvanic corrosion may be apparently observed at HAZ. However galvanic corrosion may be somewhat controlled by using an optimum welding electrode.

• Animal cells and systems
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• 제14권4호
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• pp.245-252
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• 2010

Iron uptake in mitochondria and fractionated mitochondria compartments was studied to understand iron transport in heart mitochondria. The inner membrane is most active in iron uptake. Mitochondrial uptake was dependent on iron concentration and the amount of mitochondria. Iron transport was inversely proportional to pH in the range of 6.0 to 8.0. Iron transport reached a maximum after 30 min of incubation at $37^{\circ}C$. Iron uptake was inhibited by 1 mM ATP and stimulated by 1 mM ADP. The oxidative phosphorylation inhibitor oligomycin inhibited iron uptake, but rotenone and antimycin A did not. The divalent ions $Mg^{2+}$, $Cu^{2+}$, $Mn^{2+}$, and $Zn^{2+}$ suppressed iron uptake at $10\;{\mu}M$ and stimulated it at 1 mM. The divalent ion $Ca^{2+}$ stimulated iron uptake at $10\;{\mu}M$ and suppressed it at 1 mM, competing with iron. The uptake of calcium was stimulated by 10 to $1000\;{\mu}M$ ATP, while iron uptake was stimulated reciprocally by 10 to $1000\;{\mu}M$ ADP, suggesting that these ions have movements similar to those of ATP and ADP.

• 자원리싸이클링
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• 제21권4호
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• pp.35-43
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• 2012

본 연구는 날로 그 발생량이 증가하고 있는 산성광산배수의 처리과정에서 발생하는 슬러지를 재활용하기 위하여 수행되었으며, 슬러지의 주성분인 수산화철[$Fe(OH)_3$]이 중금속에 대한 흡착 능력이 우수한 점을 이용하여 슬러지를 광해방지용 중금속흡착제의 제조 원료로 활용하기 위한 연구를 수행하였다. 먼저 슬러지의 물성파악을 위하여 슬러지의 화학조성, 광물조성, 입도, 형상 등을 조사하였고 슬러지 첨가량, 시간, pH, 중금속 농도, 소결온도에 따른 중금속 종별 흡착능을 조사 검토하였다.

• 자원리싸이클링
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• 제14권3호
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• pp.48-54
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• 2005

FeCl$_3$용액으로 니켈프레임을 에칭하는 과정에서 발생한 폐액으로부터 철과 니켈을 분리, 회수하기 위해 용매추출과 환원실험을 수행했다. 추출제로 Alamine336을 사용하여 철과 니켈의 분리가 가능했으며, 유기상과 에칭폐액의 부피비가 7이상의 조건에서 99%의 철의 추출율을 얻었다. 0.01 M농도의 염산용액을 탈거액으로 사용하여 탈거액과 유기상의 부피비가 7인 조건에서 99%의 철 탈거율을 얻었다. 추출여액의 pH가 10.5이고 반응온도가 100$^{\circ}C$인 조건에서 환원제로 히드라진을 첨가하여 99%의 순도를 지닌 니켈 금속 분말을 얻었다. 용매추출과 화학환원을 이용하여 에칭폐액으로부터 니켈금속을 회수하고, 에칭액을 재생할 수도 있는 공정을 제시하였다.

• 환경위생공학
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• 제24권1호
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• pp.25-32
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• 2009

The analyzed results of the heavy metal concentration of air and soil at the D iron-manufacturing company area were as follows; The concentration of $PM_{2.5}$ in the case area exceeded the air standard level in 3 seasons except summer. The $PM_{10}$ level was similar to the standard level, which was similar to the standard level, which was $50{\mu}g/m^3$. The Pb concentration of air in the case area was $0.13{\mu}g/m^3$, which was slightly higher than $0.11{\mu}g/m^3$ in the control area. The concentration of Cd and Cr were higher in the control area. The heavy metal (Pb) concentration of soil in the case area was $10.7{\mu}g/m^3$, which was higher than that of the control area. For these results, it is necessary for the D iron-manufacturing company area to consider a counter plan for dusts and are duction plan for the heavy metal (Pb).