• Journal of Conservation Science
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• v.30 no.3
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• pp.249-261
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• 2014

This study aims to examine production technique of white wares from the Guyre-2ri 1st and 2nd kiln sites, Wonju, Gangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. White wares from the Guyre-2ri kiln sites contained high contents of coloring oxides and fluxes. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$ and some of them experienced a low temperature of $1000^{\circ}C{\pm}20^{\circ}C$ and a high temperature above $1200^{\circ}C$. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples, and the proportions were similar to each other. When analyzing the excavated white wares using the Seger formula, also, all the samples showed similar clay sources and production techniques. Moreover, the white wares were made of host rocks of the same geological origin, according to the result of rare earth elements analysis.

• The Journal of the Petrological Society of Korea
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• v.5 no.2
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• pp.188-199
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• 1996

Boeun granodiorite, which intruded into the metasedimentary rocks of the Ogcheon Group, show chemical natures of metaluminous and calc-alkaline. Generating and emplacing environment of the Boeun granodiorite would have been a active continental margin. Comparing to the contemporaneous Inje-Hongcheon granodiorite in the Gyeonggi massif, the Boeun granodiorite seems likely to have formed under more immature continental arc environment. Compositional changes of major, trace and rare earth elements in granodiorite and felsic dyke are not certain to indicate crystallization differentiation. From this fact, the simple fractional crystallization model would be in question to explain the magma process which controlled the formation of the Boeun granitic mass. The model calculations for Rayleigh fractionation, fractionation with variable major-component composition, assimilation-fractional crystallization (AFC) were carried out to examine the magma process of the mass. The results of former two models do not agree with the compositional variations in the mass. The AFC model can be, however, applied to the magma process. The conditions for AFC process are (1) composition of assimilated wallrock is similar to that of primary magma. (2) assimilating rate is similar to crystallizing rate, and (3) mass of assimilated wallrock is about 10% of that of the magma. These conditions deny a possibility that the assimilated wallrock was the metasedimentary rocks of the Ogcheon Group. This indicates that after having experienced the assimilation process in deeper crust, the granodiorite magma intruded into the Ogcheon group. Every model calculating suggests that the felsic dyke was differentiated not from the granodiorite magma, but from a different source magma.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.327-332
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• 1999

Manganese (Mn) oxides in soils have been a research subject since they react with nutrients and contaminants and Mn itself is an essential element for plant growth. Birnessite was synthesized in the presence of iron (Fe) in the precipitating solution. Influence of Fe, one of common elements in soils, on crytallinity, morphology, and chemical reactivity of birnessite was examined using X-ray diffraction (XRD), electron microscope, canon exchange capacity (CEC), and chromium (Cr) oxidation capacity. With increasing Fe concentration in the precipitating solution, crystallinity and crystal size decreased. Hexagonal plates of the birnessites formed at low Fe concentration were dominant and replaced more and more by aggregate of small particles with increasing the Fe concentration. There is no significant change in CEC with changing the Fe concentration. Chromium oxidation capacity of the birnessite increased with increasing the Fe concentration. Iron in the precipitating solution poisoned crystal growth by adsorption on the surface and increased nucleation. Since Fe is a common constituent under pedogenic environment and Fe and Mn oxides often coexist in Mn oxide nodules, the birnessite with small particle, low crystallinity, and high chemical reactivity is the form which is more likely to be formed in soils. The high CEC ($140cmol_ckg^{-1}$) and oxidation capacity of birnessite indicate that birnessite can be used in environment and agriculture.

• Journal of IKEEE
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• v.22 no.4
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• pp.1062-1067
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• 2018

In this study, the research processed with a chemical sensor for measuring trace amount of heavy metal ions which is based on the requirements of the efficient sensing technology as recent equipment is applies molecular system in the chemical sensing section that can precisely recognizing selective target substance and transmit its data to physical signal as a result. In this research is concentrated on realize highly precise by utilizing SPR sensor application of recognition functional sensing membrane. Consequently, according to DTSQ-dye sensing membrane, the resonance angle from low-concentration to the highest concentration $10^{-4}M$ of $Ag^+$ ion is $2.17[^{\circ}]$ and this result indicating 4.3 times larger resonance angle changes compare to the other metal substance. Based on SQ-dye sensing membrane, the difference of resonance angle between low concentration and the highest concentration $10^{-4}M$ of $Cu^{2+}$ ion is $2.3[^{\circ}]$ and this outcome is indicating 4.5 times greater resonance angle change to the other metal substance.

• Economic and Environmental Geology
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• v.45 no.6
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• pp.599-622
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• 2012

The phase I soil geochemical exploration was carried out targeting around Chau Binh area far from about 14 km with southeastern direction from Quy Chau within Nghe An province. The interval of sampling are horizontal 300 m with 14 line and longitudinal 500 m with 15 line, resulting in 194 soil samples. Based on the result of the phase I soil geochemical exploration, the phase II detailed pitting survey was carried out targeting the grid point with high TREO content, resulting in 56 soil samples within 7 pits. The geology of survey area are consisted of Ban Chieng biotite granite complex and Dai Loc gneissic granite complex intruding Bu Khang formation comprising of schist, gneiss and limestone. Main mineralization in the study area have the characteristics of occurrence with tin, ruby and REE-bearing monazite(about 300 g/t) and xenotime(about 10 g/t) to be thought as occurring at the alteration zone of granite complex. In order to elucidate the source rock of monazite and xenotime confirmed from heavy sand, soil geochemical exploration was carried out. As a analysis result with ICP-MS on the soil samples from the phase I soil geochemical exploration, total REE oxide content of background amount to about 2 times of crustal abundance, enriching the heavy rare earth(about 2 times) and light rare earth(about 1.84 times). As a analysis result with ICP-MS on the soil samples from the phase II soil detailed pit survey, we identified outcrop considering as economic ore body at the grid point 4-7 pit with N40W attitude. As a synthetic consideration on the phase I soil geochemical exploration and phase II detailed pit survey, we tentatively designated areas considering as the extension of economic ore body with REE anomaly. In the near future, we have the plan to carry out the geophysical exploration and test drilling targeting the interval anticipated to the economic ore body.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.555-566
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• 2006

Major, trace and rare earth elements data of the Cretaceous Jindong granitic rocks were investigated in order to constrain the magma source characteristics and to establish the paleotectonic environment of the southwestern part of the Gyeongsang Basin. Geochemical signatures of the granitic rocks from the study area indicate that all of the rocks have characteristics of calc-alkaline series in the subalkaline field, and progressively shift from metaluminous to peraluminous with differentiation. In the variation diagrams, the overall geochemical features of the granites show systematic variations in major and trace elements. Chondrite normalized REE patterns show generally enriched LREE((La/Yb)c=4.2-12.8) and slight negative to flat Eu anomalies. Rb-Sr isotope data of the Jindong granites show that the whole rock age and Sr initial ratio are $114.6{\pm}9.1Ma$ and 0.70457, respectively. The Sr initial ratio of the Jindong granites is very similar to those of the Creataceous granites from Masan, Kimhae and Busan area($^{87}Sr/^{86}Sr=0.7049-0.707$). These results suggest that the magma have the mantle signature and intruded into the area during the early Cretaceous age. The Jindong granites have higher $Al_{2}O_{3},\;Na_{2}O$, Sr and lower $K_{2}O$, Y concentrations compared with typical calc-alkaline granitic rocks. These adakitic signatures are similar to those of adakitic pluton on Kyushu Island, southwest Japan arc. On the ANK vs. ACNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type, VAG granite. Interpretations of the geochemical characteristics of the granitic rocks favor their emplacement at continental margin during the subduction of Izanagi plate.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2001.06a
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• pp.132-132
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• 2001

옥천변성대의 충주-황강리 지역내 앰피볼라이트의 기원암은 염기성 화성암으로 쏠레이아이트 계열의 변이질암에 속한다. Fe $O^{*}$/MgO값의 변화에 대하여 분별작용에 의해 영향을 받는 주성분 원소와 미량원소들의 변화를 보게되면 Ti $O_2$, Fe $O^{*}$와 불호정성 원소(incompatible element)인 Zr, Nb, Hf, Ta, Th 등은 분별작용동안 증가하는 반면 호정성 원소(compatible element)인 MgO, $Al_2$ $O_3$, Ni, Cr 등은 감소하는 경향을 보여주고 있다. Fe $O^{*}$/MgO, Ti $O_2$ 그리고 Fe $O^{*}$는 심해성 쏠레이아이트 영역으로부터 분화된 경향을 나타내 주고 있다. Ni, Cr은 Fe $O^{*}$/MgO값의 증가에 따라 급속히 감소하며 안정한 대륙과 해저화산의 영역에 도시되고 있으며 칼크-알칼리(CA)와는 관계가 없고 쏠레이아이트의 영역에서 변화 패턴을 보여주어 앰피볼라이트가 활동적인 대륙연변부의 지구조 환경보다는 안정한 대륙이나 해저화산과 관계가 더 있음을 시사한다. 경휘토류 원소(LREE)는 중휘토류 원소(HREE)에 비해 더욱 부화된 특성을 띠고 원자번호가 증가하면서 표준화된 휘토류 원소패턴의 경사가 점차 감소하는 경향을 보여주고 있다. 대부분의 시료들은 큰 Eu이상치를 갖고 있지 않아 마그마 정출 과정동안 사장석의 분별작용이 거의 수반되지 않았음을 지시하고 전체적인 휘토류 원소의 패턴은 거의 평행하게 나타나므로 기원 마그마가 유사함을 의미하고 있다. 비유동성 원소를 이용한 여러 판별도표들을 통해서 본암은 대륙성 현무암질암으로서 판내부 환경에서 유래되었으며 대륙내부 열곡의 알칼리 현무암과 대륙성 현무암 영역에 속하는 것으로 보아서 대륙지각내 열곡작용과 같은 장력운동에 수반되어 생성된 것임을 시사해 주고 있다. 앰피볼라이트의 지각혼성화를 평가하기 위해 이에 필요한 몇 개의 지화학적 매개변수를 계산한 결과 La/Ta, La/Nb, Nb/Th들의 값이 오염 안된 마그마의 값을 지시해 주어 본암이 지각혼성화 작용을 받지 않은 것으로 나타났다. 대부분의 시료들은 P-타입 MORB의 영역에 속하며 소수의 시료가 T-타입 MORB의 영역에 도시되고 있어 본 앰피볼라이트의 생성에는 양적으로 다른 두 가지의 유사한 마그마가 수반된 것으로 추정된다. 것으로 추정된다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.84-84
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• 2009

$BaTiO_3$는 perovskite 구조를 가지는 대표적인 강유전체 재료로서 MLCC (Multi Layer Ceramic Capacitor), PTC thermistor등에 널리 사용되어지고 있다. 최근 고용량 MLCC의 상업화와 함께 나노크기를 갖는 tetragonal phase의 $BaTiO_3$ 입자를 합성하기 위한 다양한 제조방법이 제시되고 있다. 또한 유전특성과 온도특성 및 신뢰성을 향상시키기 위해 많은 첨가제들이 연구되어지고 있다. 따라서 본 연구에서는 희토류 원소인 $Y_2O_3$를 첨가하여 유전특성 및 온도특성을 향상시키고자 하였다. 본 실험에서는 150nm 크기를 갖는 pure $BaTiO_3$ 분말을 사용하고 $Y_2O_3$의 양은 0.02 ~ 0.1wt%로 변수를 주어 첨가하였으며, 최적의 소결 조건을 찾기 위하여 1200, 1230, $1250^{\circ}C$에서 소결을 진행하였다. 실험방법으로는 균일한 혼합을 위하여 Iso-alcohol을 이용하여 48시간 ball-mill 하였으며 오븐에서 건조 후 ${\Phi}15$로 성형하여 소결을 진행하였다. 실험결과로는 $Y_2O_3$ 첨가량이 0.02wt% 부터 상온부터 상전이 온도 부근의 유전율 기울기는 완만해 지는 것을 확인할 수 있었으며, 소결시편의 정방정비 (tetragonality)도 뚜렷하게 나타났다. $Y_2O_3$ 첨가랑이 0.1 wt% 일 때는 첨가량의 증가로 인해 강유전성이 상쇄됨을 나타냈다. 이는 $2450^{\circ}C$에 이르는 매우 높은 용융온도와 $2350^{\circ}C$까지 상전이가 는 $Y_2O_3$를 미량 첨가할 때, 고온에서 높은 화학적 안정성과 내열성을 가져 온도 안정성이 향상된 것으로 판단된다.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.269-279
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• 1996

The porous armophous catalysts, composed of $SiO_2-TiO_2-V_2O_5$ were prepared through SOL-GEL process by differing the preparation parameters. Selected the optimum SOL-GEL catalyst which has the best NO removal activity through the screening test, and repeated coating it on the cordierite monolith which is the freely through and inert. And examined the NOx, SOx simultaneous removal effect under S. C. R. condition. In addition to its characterization performances by the DTA, TGA, BET, $NH_3$ and NO TPD, ESCA, XRD etc.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.817-821
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• 1998

$BaTiO_3$ particles were prepared using $Ba(OH)_2{\cdot}8H_2O$ and $Ti(OC_2H_5)O_4$ by the hydrothermal method and their characteristics treated at the various temperatures have been investigated. This prepared $BaTiO_3$ powder includes a very small amount of $H_2O$ and $OH^-$. By increasing the treated temperature from $200^{\circ}C$ to $1000^{\circ}C$, the mean particle size was accordingly increased from $0.022{\mu}m$ to $0.072{\mu}m$ and the tetrogonality(c/a)was increased from 1.02 to 1.2 so that the phase transition to tetroganal takes place. $BaTiO_3$ sintered at $1250^{\circ}C$ after heat treatment at $400^{\circ}C$ for 3 hrs showed a specific dielectric constant of 8120 and surface activation energy was 9680 kcal/mol.