• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.152-153
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• 2015

알루미늄 공기전지의 환원전극으로 많은 재료들이 쓰이고 있지만 그중에서도 니켈은 값이 싸며 전기 전도도가 높아 많이 쓰이고 있다. 니켈 메쉬표면에 이산화망간을 촉매로써 처리하지만 이산화망간 용액을 적시고 말리는 기존방법에서는 균일하게 처리가 되지 않고 공기가 통하지 않는 경우도 있기 때문에 보다 균일한 처리를 위해 전해도금을 연구하였다.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.296.1-296.1
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• 2008

• Proceedings of the Korean Magnestics Society Conference
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• 2016.11a
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• pp.42-42
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• 2016

• Economic and Environmental Geology
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• v.46 no.5
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• pp.375-390
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• 2013

The Kenticha rare-element (Ta-Li-Nb-Be) mineralized zone is located in ophiolitic fold and thrust complex of southern Ethiopia and was firstly discovered by joint exploration program of Ethiopia-Soviet in 1980s. It includes Dermidama, Kilkele, Shuni Hill, Kenticha, and Bupo pegmatites from south to north. The Kenticha pegmatite intruded parallel to NS-striking serpentinite and talc-chlorite schist, and is exposed approximately 2 km length and 400-700 m width. The Kenticha pegmatite is internally zoned and subdivided into lower quartz-muscovite-albite granite, intermediate muscovite-quartz-albite-microcline pegmatite, and upper spodumene-quartz-albite pegmatite, based on their mineral assemblage. The major, trace elements (e.g., Rb, Li, Nb, Ta, and Ga), and element ratios (e.g., K/Rb, Nb/Ta, Mg/Li, and Al/Ga) suggest that the fractionation and solidification of pegmatite have progressed from the lower towards upper pegmatite. In contrast, unlike general magmatic fractionation, Mg/Li ratios of the Kenticha pegmatite tend to be increased towards the upper pegmatite. It may result from post-magmatic hydrothermal alteration and/or interaction with upper ultramafic rock. Rare-element mineralization in Kenticha pegmatite concentrates on the upper pegmatite, which contains up to 3.0 wt % $Li_2O$, 3,780 ppm Rb, 111 ppm Cs, 1,320 ppm Ta, and 332 ppm Nb. Ore minerals in Kenticha pegmatite mostly include tantalite, spodumene, and lepidolite, and tantalite has an association with coarser quartz-spodumene and relatively fine sacchroidal albite. The tantalite is classified into Mn-tantalite as a function of $Mn^*[Mn/(Mn+Fe)]$ and $Ta^*[Ta/(Ta+Nb)]$ values. Its compositions ($Mn^*$, $Ta^*$, and Nb/Ta) between coarse and fine tantalites are different and the former is strongly enriched in Ta and depleted in Nb compared to latter one. In conclusion, rare-element mineralization in the Kenticha pegmatite may has occurred in the latest stage of magmatic fractionation.

• Journal of environmental and Sanitary engineering
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• v.6 no.1
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• pp.47-62
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• 1991

Yellow Sand Phenomena was observed from April 8 th to 10 th in 1990. During this period particle was collected to investigate the chacteristics of chemical composition of particulate by High Volume Air Sampler and Andersen Air Sa~npler in Seoul. During this period the particle concentration was 350 yg/$m^3$ and the anions, cations, and metal concentrations were increased and the orders of these were $S0_4\;^{-2}>N0_3\;^->Cl^->F^-, Na^+>Ca^{+2}>NH_4\;^+>Mg^{2+}>K^+$, and Fe>Al>Si>Zn>Pb respectively. The principal source of Yellow Sand were identified soil and sea salt. Mn used by the trace element of soil, the persentage of contribution from soil was calculated to be about 81.3% for the particle increased by Yellow Sand Phenomena. Also the principal chemical compounds of particle were estimate metals(Fe, Al, Si, Zn) oxides, $CaSO_4, NaSO_4, MgSO_4, NaC1, MgCl_2$ and $(NH_4)_2SO_4$.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.52-58
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• 2000

This study was carried out to investigate the contents of heavy metals with respect to the depth, particle size and Tessier et al. method in surface sediment of the Nakdong river. The contents of Cd, Cu & Pb were high or similar with increasing depth, but Mn & Zn were high to middle depth. Generally, the contents of heavy metals were found to be high as the particle size become more small and more deep. Because the more particle size was small, the specific surface area was large, the contents of heavy metals was high for increasing affinity. It was estimated that the types of heavy metals contained in surface sediment by Tessier et al. method was dissimilar with anaerobic condition, pH and degradation of organic matter, etc.

• Journal of the Korean institute of surface engineering
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• v.24 no.1
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• pp.25-30
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• 1991

The evaporation characteristics of Ag, Al, Au, Cr. Cu, In, Mg, Mn, Pb, Pd, Si, SiO, Sn, Ti and Zn with the various resistive heating sources have been studied. The employed sources are refractory metal (Mo, Ta and W) boats, W-wire, ceramic (usually Al2O3)-coated and -barriered refractory metal boats, and special boats such as baffled boats and intermetallic boats (nitride compound and graphite). We investigated the melting mode, evaporation rate at a specific power, and lifetime of the sources. A special boat holder is also discussed which is needed to cool the sources at a large heat capacity.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.3
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• pp.277-284
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• 2005

Catalytic oxidation of toluene in low concentrations was investigated over various supports. As the manganese oxides loading was increased, the conversion of toluene increased at a lower temperature. The 18.2 $wt\%$ $Mn/\gamma-Al_2O_3$ appeared to be the most active catalyst. Among the supports, $\gamma-Al_2O_3$ was more active than $TiO_2$ and $SiO_2$. Manganese oxide catalysts prepared from manganese nitrate precursor were better for complete oxidation of toluene than those prepared from manganese sulfate and chloride precursor because sulfate from manganese sulfate and chloride from chloride manganese remained even after the calcination by XRD (X-Ray Diffraction) analyses.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.4
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• pp.43-47
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• 2009

Soil aggregation is an important part of influencing the soil behaviors in reducing rainfall-runoff and soil erosion, aeration, infiltration, and root penetration. Some inorganic materials such as clay minerals, Fe and Al oxides/hydroxides, and calcium carbonate can act as cementing agents within macroaggregates. The objective of this study was to determine the effects of different cementing agents (Fe, Mn, and Al) on soil aggregate formation in reclaimed tidelands. Water stable aggregate ratio and MWD (mean weight diameter) were higher in iron dioxides treatment than two other treatments. This result indicates significant correlation between soil aggregate formation and iron dioxides.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.50-51
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• 2002

최근 실온에서 약 40％ 이상의 높은 자기저항(magnetoresistance, MR)을 나타내는 자기 터널 접합(magnetic tunnel junction, MTJ)이 보고되면서 비휘발성 자기메모리로의 응용을 눈앞에 두고 있다.[1]. 이에 본 실험에서는 Substrate / Ta (base electrode) / NiFe / PtMn (AF pinning layer) / CoFe (pinned) / Ru / CoFe (fixed) / Al-O/ CoFe (free) / NiFe (free) / Ta & Ru (Capping Layer)과 같은 MTJ 증착 구조를 사용하여, MTJ의 보다 향상된 특성을 확보하기 위한 노력으로서 Al-O 두께, 어닐링 조건(Field Intensity ＆ Sequence)변화 등을 시도하였다. (중략)