• 자원환경지질
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• 제30권1호
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• pp.1-14
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• 1997

The shales from the Euiseong area are interbedded along the bedding in Cretaceous Gyeongsang Supergroup, which are composed mainly of quartz, plagioclase, K-feldspar and associated with trace amount of biotite, muscovite, chlorite, pyrite, hematite, carbonate and clay minerals. The ratio of $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ in shales from the Shindong Group are ranged from 9.16 to 24.32 and from 1.70 to 5.97, and the Hayang Group ranged from 2.76 to 8.89 and from 0.42 to 2.74, which are negative correlated between $K_2O/Na_2O$ and $Al_2O_3/Na_2O$ against $SiO_2/Al_2O_3$ respectively. Those are suggested that controlled of mineral compositions in shales due to substitution and migration of elements by sedimentation and diagenesis. These shale formation were deposited in basin of terrestrial environments originated from the igneous rocks, and the REE of these rocks are not influenced with diagenesis and hydrothermal alterations on the basis of $Al_2O_3$ versus La, La against Ce, Zr versus Yb, the ratios of La/Ce (0.43 to 0.62) and Th/U (1.11 to 10.71). The narrow range in trace and REE element characteristics as Co/Th (0.63 to 1.92), La/Sc (1.98 to 5.90), Sc/Th (0.58 to 1.30), V/Ni (0.90 to 3.25), Cr/V (0.45 to 1.78), Ni/Co (1.88 to 6.67) and Zr/Hf (30.04~60.87) of these shales argues for inefficient mixing of the simple source lithologies during sedimentation. These rocks also show much variation in $La_N/Yb_N$ (6.90 to 17.02), Th/Yb (4.17 to 13.68) and La/Th (1.98 to 5.90), and their origin is explained by derivation from a mixture of intermediate to acidic igneous rocks.

• 상하수도학회지
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• 제22권3호
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• pp.379-387
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• 2008

The pH & alkalinity adjustment method by lime and carbon dioxide($CO_2$) for corrosion control in water distribution system was investigated to evaluate the corrosion characteristics of metal pipes, such as galvanized iron, copper, stainless steel, and carbon steel. When the pH in sand filtered and ozone+GAC treated water was increased with lime and $CO_2$ from 7.5 to 8.0, the concentration of residual chlorine decreased at higher pH and longer reaction time; the concentration of trihalomethane increased. The corrosion rate of coupons with corrosion control using lime and carbon dioxide was showed much smaller than those without corrosion control using pilot-scale simulated distribution system. The galvanized iron was corroded much faster than carbon steel, copper, and stainless steel. Especially, copper and stainless steel coupons were hardly corroded. The galvanized iron and carbon steel coupons with corrosion control were produced the corrosion products less than those without corrosion control by the results of environmental scanning electron microscope(ESEM) and energy dispersive x-ray spectroscopy(EDS) analyses. The galvanized iron coupon with pH and alkalinity adjustment by lime and carbon dioxide was detected about 30 percent of zinc, when the carbon steel was detected about 30 percent of calcium by calcium carbonate products formation. For the results of X-ray diffraction(XRD) analyses, the goethite(${\alpha}$-FeOOH) was identified as primary corrosion product of galvanized iron without corrosion control, while the Zinc oxide(ZnO) was found on corrosion products of galvanized iron coupon with corrosion control as the results of EDS analyses. However, the carbon steel corrosion products regardless of corrosion control were composed predominantly of maghemite(${\gamma}-Fe_2O_3$) and hematite(${\alpha}-Fe_2O_3$).

• 한국지구과학회지
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• 제23권1호
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• pp.97-104
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• 2002

Mulgeum, Yangseong, Maeri and Kimhae iron ore deposits in Gyeongnam Province are hydrothermal skarn type magnetite ore deposits in propylitized andesitic rock near the contact with Cretaceous Masanite. Symmetrical zoned skarns are commonly developed around the magnetite veins. The skarn zones away from the vein are quartz-garnet skarn, epidote skarn and epidote-orthoclase skarn. Oxygen isotope analyses of coexisting minerals from andesitic rock, Masanite and major skarn zones, and of magnetite, hematite and quartz were conducted to provide the information on the formation temperature, the origin and the evolution of the hydrothermal solution forming the iron ore deposits. Becoming more distant from the ore vein, temperatures of skarn zones represent the decreasing tendency, but most ${\delta}^{18}O$ and ${\delta}^{18}O_{H2O}$ values of skarn minerals represent no variation trend, and also the values are relatively low. Judging from all the isotopic data from the ore deposits, the major source of hydrothermal solution altering the skarn zones and precipitating the ore bodies was magmatic water derived from the deep seated Masanite. This high temperature hydrothermal solution rising through the fissures of propylitized andesitic rock was mixed with some meteoric water, and occurred the extensive isotopic exchange with the propylitized andesitic rock, and formed the skarns. During these processes, the temperature and ${\delta}^{18}O_{H2O}$ value of hydrothermal solution were lowered gradually. At the main stage of iron ore precipitation, because all the alteration was already finished, the new rising hydrothermal solution formed only the magnetite ore without oxygen isotopic exchange with the wall rock.

• 보존과학회지
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• 제28권2호
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• pp.101-112
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• 2012

동관왕묘(보물 제142호)는 조선시대(1602)의 건축물로서 관우, 장비, 우장군, 주창 및 조자룡 등의 소조상이 안치되어 있다. 이 소조상들의 채색층은 먼지 등 무기오염물로 인해 안료의 원색이 손상되었으며, 수차례의 보수 및 덧칠로 인해 원형이 훼손되어 있다. 소조상의 채색안료에 대한 정밀분석을 위해 X-선 회절분석, SEM-EDS, P-XRF 및 색도 측정을 실시한 결과, 적색과 갈색의 안료는 진사, 석간주, 연단이며, 연적색은 석고를 첨가하여 조색하였다. 흑색과 금색은 각각 흑연과 금(Au)박이 사용되었으며, 녹색 안료에서는 공작석, 염화동 및 해록석이 동정되었다. 매우 선명하게 발색된 청색은 현대 안료로 보채한 것으로 판단되며, 백색은 백악, 석고, 연백이 모두 검출되었다. 석황과 밀타승은 각각 황색과 연황색 채색에 사용되었다.

• 한국재료학회지
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• 제23권5호
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• pp.286-292
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• 2013

Generally, the color gold has had a biased conception due to its traditional use. Thus, this bias has resulted in a lack of usage of golden glaze on ceramics and also a lack of extensive studies of such glazes. In this paper, optimum conditions and mechanism of formation of gold color crystallization glaze containing $Fe_2O_3$(hematite), which is developed for gold colors of ceramic glazes, were studied. Experimental result showed that there are pyroxene based on diopside and $TiO_2$ phase in the base of a crystallization glaze with a value of $TiO_2$ of 6 wt% confirmed by XRD and Raman Spectroscopy. When $Fe_2O_3$ was used as a colorant for the gold color, the $TiO_2$ peak became extinct and the intensity of the diopside peak was sharper. Feldspar of 60 wt%, talc of 20 wt% and limestone of 20 wt% were used as the starting materials and these were tested using a three component system. The best result of test was selected and extended to its vicinity as an experiment to determine $TiO_2$ and $Fe_2O_3$ contents. The glaze with $TiO_2$ of 6 wt% and $Fe_2O_3$ of 12 wt% addition showed stable pyroxene based diopside crystals and the development of gold color. This gold color was obtained with CIE-$L^*a^*b^*$ values of 51.27, 4.46, 16.15 (a grayish yellow brown color), which was gained using the following firing conditions: temperature increasing speed $5^{\circ}C$/min, holding for 1 h at $1280^{\circ}C$, annealing speed $3^{\circ}C$/min till $1100{\circ}C$, holding for 2 h at $1100{\circ}C$, and finally natural annealing.

• 한국광물학회지
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• 제24권3호
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• pp.189-194
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• 2011

화성의 암권 진화 연구에서 최근 각광받는 광물은 적철석으로 대표되는 3가철 산화물이다. 물리적 방법의 하나인 잔류자화기억도 실험은 비파괴적이고 지구 기원이 아닌 고체 시료의 자화특성 규명에 유용하게 사용된다. 금번 연구에서는 알루미늄 농도를 조절하며 열수반응과 탈수반응을 통해 총 8개 성분의 3 가철 산화물을 합성하였다. 이들 시료에 대해 잔류자화기억도와 자화상실온도($T_N$)를 측정하였다. 3가철 산화물의 격자상수는 알루미늄의 3가철 함량이 증가하며 감소한다. 3 가철 산화물의 자화상실 온도 역시 알루미늄의 몰농도가 증가하며 감소한다. 알루미늄이 거의 첨가되지 않은 적철석의 $T_N$은 광물의 합성방법과 무관하게 대략 $690^{\circ}C$로 수렴한다. 탈수반응으로 합성된 3가철 산화물의 잔류자화기억도는 알루미늄의 함량에 거의 무관하게 매우 높지만, 열수반응으로 합성된 3가철 산화물의 잔류자화기억도는 알루미늄 함량이 증가하며 동반 상승한다. 상대적으로 쉽고 측정이 간단하며 비파괴적인 잔류자화기억도를 이용하면 추후 암석 내 3가철 산화물 입자의 성인 유추가 가능하며, 특히 화성의 암권 진화 규명에도 일조하리라 예상된다.

• 자원환경지질
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• 제27권4호
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• pp.335-343
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• 1994

The Eonyang amethyst deposits are composed of vug quartz emplaced in the Eonyang granites of Mesozoic Cretaceous age. The Eonyang granites are composed of biotite granite, porphyritic biotite granite, aplite and miarolitic granite. The petrochemical data of the Eonyang granites show the trend of subalkaline magma, calc-alkaline magma, I-type granitoid and magnetite series. The vug quartz show the characteristic growth zoning (white quartz-smoky quartz-amethyst) from wall side. Generally fluid inclusions in the vug quartz can be divided into four main types based on compositions (I-type: gas inclusion, II-type: liquid inclusion, III-type: polyphase inclusion, IV-type: liquid $CO_2$-bearing inclusion). Solid phase of polyphase inclusions are halite(NaCl), sylvite(KCl), hematite ($Fe_2O_3$) and unknown anisotropic solid. Homogenization temperatures inferred from the fluid inclusion study ranges from $440^{\circ}C$ to $485^{\circ}C$ in white quartz, from $227^{\circ}C$ to $384^{\circ}C$ in smoky quartz, from $133^{\circ}C$ to $186^{\circ}C$ in amethyst, respectively. Salinities of fluid inclusions in each mineralization stages ranges from 40 wt.% to 58 wt.% in white and smoky quartz, from 1.0 wt.% to 8.7 wt.% in amethyst respectively. A consideration of the pressure regime during vug quartz deposition based on the boiling evidence suggests lithostatic pressure of less than 72 bars. This range of pressure indicate that vug quartz lay at depth of 750 m below the surface at the during mineralization.

• 자원환경지질
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• 제25권3호
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• pp.283-296
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• 1992

The Keumryeong deposits is a low grade copper deposits in which copper minerals form disseminated grains and thin veinlets in felsic volcanics seem to be dacite. Alteration of the volcanics consists mainly pervasive propylitization and silicification. Potassic alteration characterized by biotite developed locally adjacent to southwestern contact of granodiorite body. Principal sulfide minerals in altered zone are mainly pyrite and lesser chalcopyrite. Chalcopyrite content in potassic zone is relatively higher than that of surrounding propylitized zone. Pyrite and chalcopyrite accompanies magnetite, molybdenite, sphalerite, pyrrhotite, arsenopyrite, pentlandite, marcasite, hematite, ilmenite, rutile, bismuthinite and native Bi as disseminations, veinlets and knots. Granodiorite body is propylitized and contains veinlets of pyrite, chalcopyrite and molybdenite. Fluid inclusions in sulfide-bearing quartz veinlets and quartz grains of felsic volcanics and granodiorite in altered zone consist of liquid-rich, vapor-rich, $CO_2-bearing$ and halite-bearing inclusions. These four types of inclusion intimately associated on a microscopic scale and indicate condensing or boiling of ore fluid during mineralization. Homogenization temperature of coexisting fluid inclusions are mostly in the range of 350 to $450^{\circ}C$. High salinity fluid contains 28.6 to 48.4 weight percent NaCI equivalent and moderate salinity fluid cotains 0.5 to 12.5 weight percent NaCl equivalent. Pressure estimated from $CO_2$ mole fraction of $CO_2-bearing$ inclusion range 160 to 375 bars. The Kigu copper deposits is a fissure filling copper vein developed 500 m south from the Keumryong deposits. Mineralogy and fluid inclusion data of the Kigu deposits are similar to that of the Keumryeong deposits. Homogenization temperature of fluid inclusions from the Kigu deposits are reasonable agreement with temperature estimated from sulfidation curve of cubanite-chalcopyrite-pyrite-pyrrhotite and pyrite-pyrrhotite mineral assemblages. Not only mineral occurrence and wall rock alteration in the Keumryeong deposits but also fluid inclusion data such as temperature, salinity, pressure and boiling evidences are similar to those of porphyry copper deposits.

• 한국재료학회지
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• 제30권9호
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• pp.447-452
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• 2020

In this work, α-Fe₂O₃ nanocrystals are synthesized by co-precipitation method and used as adsorbent to remove Cr⁶⁺, Cd²⁺, and Pb²⁺ from wastewater at room temperature. The prepared sample is evaluated by XRD, BET surface area, and FESEM for structural and morphological characteristics. XRD patterns confirm the formation of a pure hematite structure of average particle size of ~ 40 nm, which is further supported by the FESEM images of the nanocrystals. The nanocrystals are found to have BET specific surface area of ~ 39.18 m² g^-1. Adsorption experiments are carried out for the different values of pH of the solutions, contact time, and initial concentration of metal ions. High efficiency Cr⁶⁺, Cd²⁺, and Pb²⁺ removal occur at pH 3, 7, and 5.5, respectively. Equilibrium study reveals that the heavy metal ion adsorption of the α-Fe₂O₃ nanocrystals followed Langmuir and Freundlich isotherm models. The Cr⁶⁺, Cd²⁺, and Pb²⁺ adsorption equilibrium data are best fitted to the Langmuir model. The maximum adsorption capacities of α-Fe₂O₃ nanocrystals related to Cr⁶⁺, Cd²⁺, and Pb²⁺ are found to be 15.15, 11.63, and 20 mg g^-1, respectively. These results clearly suggest that the synthesized α-Fe₂O₃ nanocrystals can be considered as potential nano-adsorbents for future environmental and health related applications.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.156-156
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• 2016

The effect of nitrogen doping on the mechanical and tribological performance of single-layer tetrahedral amorphous carbon (ta-C:N) coatings of up to $1{\mu}m$ in thickness was investigated using a custom-made filtered cathode vacuum arc (FCVA). The results obtained revealed that the hardness of the coatings decreased from $65{\pm}4.8GPa$ to $25{\pm}2.4GPa$ with increasing nitrogen gas ratio, which indicates that nitrogen doping occurs through substitution in the $sp^2$ phase. Subsequent AES analysis showed that the N/C ratio in the ta-C:N thick-film coatings ranged from 0.03 to 0.29 and increased with the nitrogen flow rate. Variation in the G-peak positions and I(D)/I(G) ratio exhibit a similar trend. It is concluded from these results that micron-thick ta-C:N films have the potential to be used in a wide range of functional coating applications in electronics. To achieve highly conductive and wear-resistant coatings in system components, the friction and wear performances of the coating were investigated. The tribological behavior of the coating was investigated by sliding an SUJ2 ball over the coating in a ball-on-disk tribo-meter. The experimental results revealed that doping using a high nitrogen gas flow rate improved the wear resistance of the coating, while a low flow rate of 0-10 sccm increased the coefficient of friction (CoF) and wear rate through the generation of hematite (${\alpha}-Fe_2O_3$) phases by tribo-chemical reaction. However, the CoF and wear rate dramatically decreased when the nitrogen flow rate was increased to 30-40 sccm, due to the nitrogen inducing phase transformation that produced a graphite-like structure in the coating. The widths of the wear track and wear scar were also observed to decrease with increasing nitrogen flow rate. Moreover, the G-peaks of the wear scar around the SUJ2 ball on the worn surface increased with increasing nitrogen doping.