• 접착 및 계면
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• 제24권3호
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• pp.95-99
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• 2023

본 연구에서는, 판상형의 천연 마이카에 이산화티타늄의 코팅 및 환원을 통해 라이다 인지형 검은색 소재를 제조하였으며, 이를 도료로 응용하여 라이다 실증 검증을 진행하였다. 상세히는, 졸-겔 반응을 통해 천연 마이카에 이산화티타늄을 코팅하고, 수소화붕소나트륨을 통해 검은색으로 환원하여 Black TiO₂@Mica 소재를 제조하였다. 이후, 도료로서 응용 가능성을 확인하기 위해 친수성 투명 바니시에 혼합하고 유리 기판에 분사하였다. 그 결과, 제조한 Black TiO₂@Mica 기반의 도료는 실제 검은색의 명도(L*=12.1)와 높은 근적외선 반사율(30.2 R%)을 나타내었다. 더불어, 제조한 판상형 검은색 소재는 성공적으로 라이다 센서에 인식되는 것을 확인하였다. 이는, 굴절률이 다른 천연 마이카와 이산화티타늄 간의 계면에서 빛의 반사가 일어나는 프레넬의 반사 법칙에 기인한 것이다. 본 연구 결과를 통해, 라이다 센서에 인식되는 검은색 소재를 제조함으로써 자율주행차 뿐만 아니라 로봇, 드론 등 다양한 분야에서 활용될 수 있을 것으로 기대된다.

• 한국광물학회지
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• 제13권2호
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• pp.53-64
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• 2000

Chlorite from the talc deposits in the Chungnam area, Korea, has been studied using electron microprobe analysis and high resolution transmission electron microscopy (HRTEM), Talc orea are hydrothermal alteration products of serpentinite which was originated from ultramafic rocks. Chlorite occurs in close association with talc ores of with the black alteration zone between talc ore bodies and granitic gneiss. It is the most abundant impurity mineral of talc ores. Chlorite in association with talc is characterized by very high but narrow variation in Mg/(Mg+Fe) ratios (0.784~0.951), significant octahedral substitution (-0.200~0.692), wide variation in Al contents (1.085~3.160 / 14 oxygens), and high Cr and Ni contents. It was formed under a very limited but high Mg/(Mg+Fe) condition in close connection with serpentinite. Chlorite in the black alteration zone is characterized by a high Fe content, wide variation in Mg/(Mg+Fe) ratios (0.378~0.852), narrow octahedral substitution (-0.035~0.525), high narrow Al contents (1.468~2.959), and low Cr and Ni contents. It was formed under a low Mg/(Mg+Fe) and relatively Al-rich condition in close connection with county rocks. Two different chemical modes for chlorite suggest two different origins for two different chlorites. Although most of chlorites show typical 14-$\AA$ lattice fringe images under HRTEM, some chlorites show fringe images of 21-$\AA$ (14$\AA$+7$\AA$) spacings within (001) lattice-fringe images of chlorite (14$\AA$). But brown chlorite from the black zone has high Ti and K contents suggesting that mica was the precursor of brown chlorite. Such possibility is also supported by the fact that lattice-fringe images of brown chlorite show 14-$\AA$ chlorite layers in which 10-$\AA$ mica single layer or packets are interlayered. Partial terminations from 3 mica layers to 2 chlorite layers are often observed. It, therefore, is suggested that the chlorite associated with talc ores is a hydrothermal alteration products of serpentinite, whereas the chlorites in the black alteration zone is a hydrothermal alteration product of granitic gnesis under a partial influence of serpentinite.

• Bulletin of the Korean Chemical Society
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• 제23권11호
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• pp.1531-1540
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• 2002

With the invention of the inlaying technique for celadon in the latter half of the 12th century, the Koryo potters reached a new height of artistic and scientific achievement in ceramics chemical technology. Inlaid celadon shards, collected in 1991 during the surface investigation of Kangjin kilns found on the southwestern shore of South Korea, were imbedded in epoxy resin and polished for cross-section examination. Backscattered electron images were taken with an electron microprobe equipped with an energy dispersive spectrometer. The spectrometer was also used to determine the composition of micro-areas. Porcelain stone, weathered rock of quartz, mica, and feldspar composition were found to be the raw material for the body and important components in the glaze and white inlay. The close similarity between glaze and black inlay in the microstructure suggests that the glaze material was modified by adding clay with high iron content, such as biotite, for use as black inlay. The deep soft translucent quality of celadon glaze is brought about by its microstructure of bubbles, remnant and devitrified minerals, and the schlieren effect.

• 한국전기전자재료학회논문지
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• 제30권12호
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• pp.812-816
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• 2017

$Fe_3O_4$ was prepared on the $TiO_2-coated$ natural mica substrate. The natural mica has an average particle size of $22{\mu}m$. The substrate was coated on $TiO_2$ thin films using hydrothermal synthesis at pH 1.5-2.5 at $75^{\circ}C$. The Fe precursor solution was prepared by mixing $FeSO_4$ (for $Fe^{2+}$ ion) and $FeCl_3$ (for $Fe^{3+}$ ions) with different molar ratios such as 1/2, 1/1, 2/1, 3/0, and $Fe_3O_4$ only. X-ray diffraction analysis shows that the crystal structure depends on the $FeCl_3-to-FeSO_4$ molar ratio. $Fe_3O_4$ crystal phase could be obtained at higher $FeSO_4$ contents.

• 보존과학회지
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• 제37권2호
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• pp.77-89
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• 2021

이 연구에서는 울산의 원삼국시대 장현동과 중산동 및 교동리 유적에서 출토된 흑색토기에 대하여 태토의 재료학적 특성과 제작기술을 검토하였다. 흑색토기의 표면은 흑색이지만 속심은 흑색 또는 적황색을 보인다. 현미경 관찰 결과, 태토는 붉은색 철산화물이 풍부한 토양을 사용하였으며 주로 석영과 알칼리 장석 및 운모류가 동정되었고, 부분적으로 미르메카이트 조직의 입자가 관찰된다. 또한 SiO₂와 Fe₂O₃ 및 CaO 함량에서 다소 차이가 있는 것으로 보아, 각 유적지 주변에 분포하는 모암과 태토의 조성이 영향을 준 것으로 판단되며 근거리에서 채토하여 토기를 제작한 것으로 보인다. 라만분광분석 결과, 이 토기의 흑색층에는 비정질 탄소인 연매가 사용되었다. 표면층과 접하는 기질에서는 투명한 갈색의 칠이 관찰되었고 탄소가 농집된 것으로 보아, 흑색층은 연매와 옻을 칠하여 흑색발색을 유도한 것으로 해석된다. 태토의 광물조성과 미세조직으로 볼 때 이 토기의 소성온도는 750~850℃의 범위로 추정되며, 칠은 468℃에서 열분해되었다. 따라서 흑색을 이루는 연매와 칠의 혼합층은 소지의 소성 이후에 칠해진 것으로 판단된다.

• 헤리티지:역사와 과학
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• 제50권4호
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• pp.122-147
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• 2017

중산동 유적은 선캠브리아기의 석영편암층과 운모편암층에 걸쳐 분포하며, 풍화층에는 운모, 석영, 장석, 각섬석 및 녹니석 등 다양한 비가소성 광물이 다량 포함되어 유적지의 지반을 형성하고 있다. 중산동 유적 신석기시대 토기는 다양한 갈색계열을 보이며, 일부 시료는 속심과 내면을 따라 흑심이 발달하고 예리한 빗살시문과 손누름 자국이 관찰된다. 이들은 비가소성 입자의 조성과 입도 및 분급과 원마도가 다양하여 특징적 광물조성에 따라 4 유형으로 세분하였다. I-형은 장석질 토기로 장석이 주성분이며 석영과 운모를 포함하기도 한다. II-형은 운모질 토기로 녹니석화된 운모류, 활석과 투각섬석 및 투휘석의 조합을 이룬다. III-형은 활석질 토기로 미량의 석영과 운모를 동반한다. IV-형은 석면질 토기로 투각섬석과 미량의 활석을 포함한다. 중산동 토기는 내외면의 색상이 다소 불균질하다. I-형 토기군은 장석류 함량에 따라 적색 및 황색도에 차이가 있으며, III-형 토기군과 유사하다. II-형은 적색도가 다소 높아 IV-형과 유사하다. 유적지 토양은 토기에 비해 적색 및 황색도가 높다. 전암대자율은 0.088~7.360(${\times}10^{-3}$ SI unit)의 넓은 범위이나, 각 유형별 주성분 광물에 따라 구분된다. 토기의 부피비중과 흡수율은 1.6~1.7 및 13.1~26.0%의 범위를 보인다. 각 유형별 토기군은 I-형의 유기물 고착시료 < III-형 및 IV-형 < I-형 < II-형 (IV-형의 IJP-15 포함)의 순으로 공극률과 흡수율이 증가하며 뚜렷한 영역 차이를 보였다. 이는 비가소성 입자의 종류와 입도 등에 따라 물리적 성질의 차이가 나타나기 때문이다. 중산동 토기는 다양한 재료의 혼합으로 이루어져 있으나, 유적지 토양은 중산동 토기가 갖는 모든 광물조성을 공급할 수 있는 지질조건을 갖추고 있다. 따라서 원료는 유적지 주변 석영편암과 운모편암의 풍화대에서 수급이 가능하였을 것으로 판단된다. 그러나 구성광물, 입도 및 암편이 다양한 양상을 보여 원료 채취장소가 여러 곳이었을 가능성이 높으며, 이에 따른 점토화 및 풍화도의 차이가 있는 것으로 해석할 수 있다.

• Environmental Engineering Research
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• 제20권3호
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• pp.285-289
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• 2015

Complicated and expensive seawater desalination technology is a big challenge in boron removal process. Conventional seawater desalination process of coagulation utilized for pre-treatment is difficult to remove boron. Boron can be removed more effectively in Reverse Osmosis (RO) process than any other processes. In this study, a coagulant with the name Mineral Cluster was examined its boron removal ability. Boron removal efficiency of Mineral Cluster depended on pH value and Mineral Cluster dosage. Desalination process combines the pre-treatment process with Mineral cluster diluted at the ratio of 1:2500 and the RO membrane process. The original sea water could be desalinated to drinking water quality, 1 mg/L, without any pH adjustments. Therefore, if the Mineral cluster is added without any other chemicals for adjusting pH, the desalination process would be much safer, efficient and economical.

• 자원환경지질
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• 제32권5호
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• pp.519-535
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• 1999

Precambrian metasedimetay rocks in the Sunchang Shear Zone (so-called Seologri and Yongamsan Formation) consist of black slate, phylite, mica schistm quartzite and rarely calc schist. The metamorphic rocks in the area have undergone at least three stages of metamorphism, which are two prograde (M1 and M2) and one contact metamorphism (M3). The metamorphism which made the most prevailing mineral assemblages in the area, is M2 stage metamorphism. The metamorphic grade of M2 methamorphism in metapelites increases from the Chlorite zone through Biotituzone, Garnet zone to Staurolite zone. The M1 stage metamorphism is recognized by kyanite and sillimanite pressure type regional metamorphism. The M3 stage methamorphism is represented in the contact boundary, which area is the chlorite zone and biotite zone near the Sunchang foliated granite and the namwon granite. The M3 stage methamorphism is characterized by andalusite bearing mineral assemblages. The peak temperature condition of M2 metamorphism estimated from coexising garnet and biotite (Kretz, 1990) is 518~598$^{\circ}C$.

• 자원환경지질
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• 제16권2호
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• pp.111-123
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• 1983

The studied area is situated in tho southern part of the Ogcheon fold belt, where the "Ogcheon Group" is widespread with Jurassic and Cretaceous intrusions. The regional stratigraphy may be divided into three formations, the lower pebble bearing phyllitic, the middle dark grey phyllitic, and the upper black phyllitic formations. For the purposes of the present study, the area has been partitioned to three structural subareas based on major fold axes and fault line. The main subjects of the research have been discussed from two different points, multiple deformation and minor-micro fold styles. The former is analyzed by pebble elongation, folding and lineation in a pebbly formation as well as schistosity, crenulation cleavage and crenulated lineation in the phyllitic formation. The later describes the characteristic features of fold style in each formation and structural subarea. Although minor fold axes within broad pelitic rocks usually tend to trend northeast and to plunge northward, most of these were probably formed by two stages, first a similar fold phase and second a kink fold phase. Measured structural elements indicate that crenulation cleavage in phyllite formed parallel to fold axes of folded pebble followed a NE phase of first deformation and a fold axes of pebbles diagonal to bedding of phyllite are represented by a NW phase of a second deformation. Microscopically, quartz and mica grains form a micro fold enabling one to establish tectonic levels which occur in different deformation modes in each stratigraphic sequence. Microtextures such as crenulation cleavage, kink band, aggregate band of mica and pressure shadows of porphyroblast of quartz related to qarnet and staurolite may suggest the time relation of crystallization and tectonism. The result of this study may conform that three deformation phase, NE first phase-NE second phase-NW phase, occurred in the area.

• 자원환경지질
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• 제31권5호
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• pp.415-424
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• 1998

In order to investigate soil-gas $^{222}Rn$ concentrations, Kwanak Campus (Seoul National University), Boeun (Choong-buk) and Gapyung (Kyonggi) areas were selected and classified depending on their base rock types. Radon risk indices of these study areas decrease in the order of Gapyung>Kwanak Campus>Boeun areas, and in the order of rock type as banded gneiss>granite gneiss>granite>black slate-shale>mica schist>shale-lirnestone>phyllite-schist. Radon emanating trends with water content and grain size of soils were assessed by modified Morse 3 min. method. Radon emanation increases with the increase of water content in soils which is lower than 6~16 wt.%, and decreases in the range of higher than 6-16 wt. %. It shows that Rn emanation increases with the decrease of soil grain size. Radioactivity analysis of radionuclides of 238U series in some soil samples shows that radioactive disequilibrium state between $^{226}Ra$ and $^{238}U$ exists owing to different geochemical behavior of each radionuclide, and, it is necessary to carry out radioactive isotope geochemical approach for soil-gas $^{222}Rn$ study.