• The Journal of the Petrological Society of Korea
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• v.2 no.2
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• pp.74-94
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• 1993

Metabasites and metapelites in the Mungyong area were intruded by Cretaceous granites with radius of 4-8 km. As the distance from granite body increases, the mineral assemblage of metabasite changes from amphibole + plagioclase through amphibole + plagioclase + epidote to amphibole + plagioclase + epidote + chlorite. The compositional variations of amphibole and plagioclase according to the change of metamorphic grade and bulk rock compositions are very complex. Towards the Mungyong Cretaceous granite body, the mineral assemblage of metapelite changes from chlorite+ muscovite(ch1orite zone) through biotite + chlorite + muscovite(biotite zone) to andalusite+biotite + muscovite${\pm}$chlorite or cordierite+ biotite+ muscovite${\pm}$chlorite(cordierite zone). The estimated metamorphic conditions of cordierite zone are 480~$580^{\circ}C$ 1.5-3.3 kb. The theoretical study on the thermal metamorphism caused by the Cretaceous granite with radius longer than 4 km in the Mungyong area suggests the followings: The degree of metamorphism is mainly determined not by the size of granite body but by the temperature of granite intrusion; The country rocks within 2 km from Cretaceous granite have undergone metamorphism with temperature higher than $500^{\circ}C$, which is consistent with the petrological study in the Mungyong area. Mungyong Cretaceous granite caused a low P/T thermal metamorphism to the country rocks; the amphibolite facies metamorphism to the country rocks within 1-2 km from the granite body and the epidote-amphibolite and greenschist facies metamorphism to the country rocks within 2-5 km.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.1-7
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• 1992

Sand and silt size fractions of soils which were derived from five major rocks of granite, granite-geniss, limestone, shale, and basalt in Korea were studied. Determination of the mineralogical and chemical composition of rock-forming mineral breakdown which is accompanied by the formation of secondary minerals. The chemical composition of the fraction was largely changed with the content of weatherable and resistant soil minerals such as ferromagenesian minerals, carbonates, and guartz. In the sand fractions of the soils from the granite and granite-gneiss, chlorite-vermiculite mixed layers seem to be an intermediate weathering product prior to the weathering state of the formation of vermiculite from chlorite. Kaolin minerals in the silt fractions of the soils from the granite-gneiss are considered to be formed by the pseudomorphic transformation of plagioclase. In the sand and silt fractions of the soils derived from the limestone, large amount of calcite and dolomite seems to have been inherited from the parent rocks. The primary chloritc, micas, and feldspars are considered to be formed from the weathering remains after leaching of carbonate minerals during the soil formation. In the residual soils(Gueom series) developed from the basalt, quartz and micas were coexisted with plagioclase and augite inherited from the parent rock.

• The Journal of the Petrological Society of Korea
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• v.17 no.1
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• pp.16-35
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• 2008

We study metamorphism of metasedimetary rocks and origin and evolution of leucogranite form Samcheok area, northeastern Yeongnam massif, South Korea. Metamorphic rocks in this area are composed of metasedimentary migmatite, biotite granitic gneiss and leucogranite. Metasedimentary rocks, which refer to major element feature of siliclastic sediment, are divided into two metamorphic zones based on mineral assemblages, garnet and sillimanite zones. According to petrogenetic grid of mineral assemblages, metamorhpic P-T conditions are $740{\sim}800^{\circ}C$ at $4.8{\sim}5.8\;kbar$ in the garnet zone and $640-760^{\circ}C$ at 2.5-4.5kbar in sillimanite zone. The leucogranite (Imwon leucogranite) is peraluminous granite which has high alumina index (A/CNK=1.31-1.93) and positive discriminant factor value (DF > 0). Thus, leucogranite is S-type granite generated from metasedimentary rocks. Major and trace element diagram ($R_1-R_2$ diagram and Rb vs. Y+Nb etc.) show collisional environment such as syn-collisional or volcanic arc granite. Because Rb/sr ratio (1.8-22.9) of leucogranites is higher than Sr/Ba ratio (0.21-0.79), leucogranite would be derived from muscovite dehydrate melting in metasedimentary rocks. Leucogranites have lower concentration of LREE and Eu and similar that of HREE relative to metasedimentary rocks. To examine difference of REEs between leucogranites and metasedimentary rocks, we perform modeling using volume percentage of a leucogranite and a metasedimenatry rock from study area and REE data of minerals from rhyolite (Nash and Crecraft, 1985) and melanosome of migmatite (Bea et al., 1994). Resultants of modeling indicate that LREE and HREE are controlled by monazites and garnet, respectively, although zircon is estimated HREE dominant in some leucogranite without garnet. Because there are many inclusions of accessary phases such as monazite and zircon in biotites from metasedimentary rocks. leucogranitic magma was mainly derived from muscovite-breakdown in metasedimenary rocks. Leucogranites can be subdivided into two types in compliance with Eu anomaly of chondrite nomalized REE pattern; the one of negative Eu anomaly is type I and the other is type II. Leucogranites have lower Eu concetnrations than that of metasedimenary rocks and similar that of both type. REE modeling suggest that this difference of Eu value is due to that of components of feldspars in both leucogranite and metasedimentary rock. The tendency of major ($K_2O$ and $Na_2O$) and face elements (Eu, Rb, Sr and Ba) of leucogranites also indicate that source magma of these two types was developed by anatexis experienced strong fractionation of alkali-feldspar. Conclusionally, leucogranites in this area are products of melts which was generated by muscovite-breakdown of metasedimenary rock in environment of continetal collision during high temperature/pressure metamorphism and then was fractionated and crystallized after extraction from source rock.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1314-1316
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• 1995

Basic discharge characteristics of a ferroelectric ball and mica sheet double barrier have been studied for learning the fundamentals of the barrier discharges and for checking the potential to be used as a plasma generator. It is found that plasma generation of the plasma generator was influenced greatly by the dielectric constant of the ferroelectric ball barrier and applied power frequency. As a result, there are optimum conditions of the dielectric constant as a barrier and the applied frequency to generate ozone effectively, which were ${\varepsilon}_r$=600 and f=4 kHz at the present experimental case.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.226-227
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• 2004

본 연구에서는 원자력 연구소 내에 건설할 고준위 폐기물 지하처분연구시설 부지에 관한 특성을 파악하고, 연구시설의 위치를 선정하기 위한 지질학적 연구를 실시하였다. 지표지질조사를 통하여 연구소 내에 분포하는 암석들의 분류와 선구조 분석을 실시하였고, 지구물리탐사와 시추조사를 통한 지하 암반의 분포양상과 연구시설 주변의 추정되는 파쇄대의 분포를 확인하였다. 지표지질조사결과 복운모화강암과 화강섬록암질 편마암이 점이적인 관계로 분포하고 있으며 (Fig.1, 3), 이들 화강암류 내에는 암맥상으로 중성 혹은 염기성 암맥들이 절리의 방향과 동일하게 관입 분포한다. 절리의 방향성은 N30E, N80W, NS방향으로 분포하고 있다(Fig. 2).(중략)

• Journal of the Korean Ceramic Society
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• v.22 no.1
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• pp.35-39
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• 1985

Synthetic mica $NaMg_{2.5}(Si_4O_{10})F_2 (Na-TSM)$ was treated with HCl solution and H-type exchange resin to investigate the chemical stability and the ion exchange by measuring the dissolution of chemical components and the exchanged $H^+$ ion. The replacement of $Na^+$ ion occurred in contact with HCl solution and H-type ion exchange resin at the surface of Na-TSM particles reached $Na^+$ ions at maximum value of 70~80%. $Mg^{2+}$ ion of octahedral layer became to dissolve from the pH2 solution and th amount of it dissolved in-creased almost proportional to $H^+$ ion concentration from around 0.02N $H^+$ ion equilibrium concentration. The crystalline structure of Na-TSM was destructed by dissolution of Mg2+ ion in cncentrated hydrochloric acid solution and resulted silica gel precipitation.

• Journal of the Korean Ceramic Society
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• v.24 no.3
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• pp.215-222
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• 1987

${\alpha}$-Ferric Hydrous Oxide and ${\alpha}$-Ferric Oxide were obtained as following processes that Ferric Nitrate solution was adjusted to pH 6-8 with Ammonium Hydroxide, refluxed the Iron precipitate for 1 hr. at 80$^{\circ}C$, washed it with water and Methanol (95%), dried it to obtain ${\alpha}$-Ferric Hydrous Oxide at 60$^{\circ}C$, and then heated in atmosphere to prepare ${\alpha}$-Ferric Oxide for 1 hr. at 450$^{\circ}C$. Mica particles cleaned with ultrasonicator (45KHz) in water were mixed with Ferric Nitrate solution and treated it to adsorb ${\alpha}$-Ferric Oxide on the surface of mica particles by using the abovementioned processes, but the heated temperature was at 500$^{\circ}C$. The maximum wavelength of reflected light on the surface of mica-${\alpha}$-Ferric Oxide (50%) was appeared at 546nm but -Ferric Oxide free mica only was at 436 nm. The maximum wavelength was shifted to longer when the weight ratios of ${\alpha}$-Ferric Oxide to mica was changed from 1% to 50%.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.05a
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• pp.372-374
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• 2004

최근들어 비금속광물의 구조적 특성을 이용한 활용분야가 매우 다양해지고 있다. 특히 판상광물은 차폐(은폐)력이 매우 우수하고, 층간특성을 이용한 흡착 및 저장특성이 매우 우수하다. 본 연구에서는 이와 같은 판상광물의 기본의 특성에 또 다른 기능성 물질을 흡착시킴으로써 부가적인 새로운 기능성을 갖는 친환경성 건축소재를 개발하고자 천연산 인상흑연 및 견운모를 기능성 모소재로 사용하고 미립화 및 표면 환경기능화를 위하여 BMK로 흑연입자 표면을 기능화하였다. 제조된 기능성 마감재인 닥터하우스를 모르타르에 도포하여 다양한 기능성을 측정한 결과 78% 이상의 유해가스(포름알데히드) 정화제거효과 및 99.9% 이상의 항균, 항곰팡이 효과를 갖는 것으로 나타났다.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.547-552
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• 2002

본 논문에서는 다수의 사람이 존재하는 입력영상에서 입술 움직임 정보를 이용한 실시간 화자의 클로즈업(close-up) 시스템을 구현한다. 칼라 CCD 카메라를 통해 입력되는 동영상에서 화자를 검출한 후 입술 움직임 정보를 이용하여 다른 한 대의 카메라로 화자를 클로즈업한다. 구현된 시스템은 얼굴색 정보와 형태 정보를 이용하여 각 사람의 얼굴 및 입술 영역을 검출한 후, 입술 영역 변화량을 이용하여 화자를 검출한다. 검출된 화자를 클로즈업하기 위하여 PTZ(Pan/Tilt/Zoom) 카메라를 사용하였으며, RS-232C 시리얼 포트를 이용하여 카메라를 제어한다. 실험결과 3인 이상의 입력 동영상에서 정확하게 화자를 검출할 수 있으며, 움직이는 화자의 얼굴 트레킹이 가능하다.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.151-154
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• 1988

Mica glass ceramics are known for their good electrical, mechanical, and thermal properties. These materials are produced by appropriate heat treatment of a suitable glass composition. In this paper electrical properties of mica glass ceramics with fluorcphlogopite crystalline phase have been investigated. At frequency range 1kHz-10MHz dielectric constants fall in the range fran 7.5 to 8.5 with law dissipation factors(0.002-0.008)at room temperature.