• Journal of the korean society of oceanography
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• 제32권3호
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• pp.112-119
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• 1997

Coastal sediments collected near the Youngkwang Nuclear Power Plant were analysed for major(Al$_2$O$^_3$, Fe$^_2$O$^_3$, MgO, CaO, Na$^_2$O, K$^_2$O, TiO$^_2$, MnO), trace (Ba, Sr, V, Co, Cr, Cu, Ni, Zn, Pb) metal, and P$^_2$O$^_5$ contents. The composition of bulk metals from most stations fits within the range as those in the average crustal and sedimentary rocks, suggesting that the anthropogenic perturbation of these components is insignificant. The abundance and distribution of total contents for the majority of metals in the surface sediment could be explained by the grain size and were associated with mud (<63 ${\mu}$m) contents. However, distributions of Ca, K, Sr and Ba did not have any significant association with the sediment grain size. This may be due to the geochemical coherence among these metals in certain minerals abundant in coarse grained fractions. The distribution of Pb appears to be partly affected by the contribution from aerosol fallout. Using the R'-mode factor analysis, we show that the variance of the metal contents could be explained by four factors which account for 93.7% of the total variance. It appears that texturally controlled and/or sorting factors influenced by fine fraction are the most dominant factors which determine the relative abundance and distribution of metals in the study area.

• 자원환경지질
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• 제56권6호
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• pp.745-764
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• 2023

In the Republic of Congo, Banded iron formations (BIFs) occur in two areas: the Chaillu Massif and the Ivindo Basement Complex, which are segments of the Archean Congo craton outcropping in the northwestern and southwestern parts of the country. They show interesting potential with significant mineral resources reaching 2 Bt and grades up to 60% Fe. BIFs consist mostly of oxide-rich facies (hematite/magnetite), but carbonate-rich facies are also highlighted. They are found across the country within the similar geological sequences composed of amphibolites, gneisses and greenschists. The Post-Archean Australian Shale (PAAS)-normalized patterns of BIFs show enrichment in elements such as SiO₂, Fe₂O₃, CaO, P₂O₅, Cr, Cu, Zn, Nb, Hf, U and depletion in TiO₂, Al₂O₃, MgO, Na₂O, K₂O, Sc, Th, Ba, Zr, Rb, Ni, V. REE diagrams show slight light REEs (rare earth elements; LREEs) compared to heavy REEs (HREEs), and positive La and Eu anomalies. The lithological associations, as well as the very high (Eu/Eu^*)_SN ratios> 1.8 shown by the BIFs, suggest that they are related to Algoma-type BIFs. The positive correlations between Zr and TiO₂, Al₂O₃, Hf suggest that the contamination comes mainly from felsic rocks, while the absence of correlations between MgO and Cr, Ni argues for negligeable contributions from mafic sources. Pr/Pr^* vs. Ce/Ce^* diagram indicates that the Congolese BIFs were formed in basins with redox heterogeneity, which varies from suboxic to anoxic and from oxic to anoxic conditions. They were formed through hydrothermal vents in the seawater, with relatively low proportions of detrital inputs derived from igneous sources through continental weathering. Some Congolese BIFs show high contents in Cr, Ni and Cu, which suggest that iron (Fe) and silicon (Si) have been leached through hydrothermal processes associated with submarine volcanism. We discussed their tectonic setting and depositional environment and proposed that they were deposited in extensional back-arc basins, which also recorded hydrothermal vent fluids.

• 자원환경지질
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• 제45권5호
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• pp.535-549
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• 2012

이 연구의 주목적은 영광-나주지역에 분포하는 송림-대보화강암류를 지질시대, 광물조성, 화학성분과 조직에 따라 각섬석-흑운모화강섬록암, 흑운모화강암, 반상화강암과 복운모화강암의 네가지 암상으로 구분하였다. 이들 화강암류는 동원마그마로부터 분화된 일련의 분화산물로 이루어진 화성암 복합체이며, 페름기말에서 트라이아스기 사이에 옥천습곡대와 영남육괴 사이에서 지괴들의 충돌운동으로 유발된 응력장하에서 형성되었고, 그리고 이 변형대의 형성기에 전후하여 정치된 화강암류가 대보운동을 받아 엽리상화강암류와 비변형화강암류를 형성하였다. 이들 영광-나주지역에 분포하는 화강암질암류의 구성광물 성분은 사장석, 흑운모. 백운모와 각섬석으로 구성되어있다. 사장석은 오리고클레스($An_{19.3-27.7}$)와 안데신($An_{28.4-31}$)성분에 해당하며 누대구조의 성분변화도 좁은영역에 치우치면 이는 느린 결정작용과 이들 결정들의 성장이 최종고결작용 이전에 일어났음을 보여준다. 흑운모의 Mg 함량은 산소의 압력과 분화도의 증가에 따른다(프로고파이트에서 시데로피라이트로 변함). $Al^{iv}$/$Al^{total}$ 관계는 전체 알루미나양에 따라 증가한다. 백운모는 일차기원이며 높은 $TiO_2$함량을 보이는 세라도나이트이다. 각섬석은 회각섬석류에 속하며 지질압력계로 계산한 화강암질암의 고결심도는 11.3-17.2 Km이다.

• 자원환경지질
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• 제25권4호
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• pp.435-446
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• 1992

REE, major and trace elements analyses of the Jurassic Daebo granite and Cretaceous Bulguksa granite were carried out to interpet their petrogenesis and relationships between petrogenesis and tectonics. Analytical results are summarized as follows. (1) $SiO_2$ content of the Bulguksa granite (aver. 74.6%) are significantly higher than those of the Daebo granite (aver. 68.1%). Major elements of $TiO_2$, $Al_2O_3$, $P_2O_5$, CaO, MgO, Total FeO, and trace elements of Co, V and Sr are negatively correlated with $SiO_2$. Incompatible elements such as Ba, Sr, Y, Zr and HREE are contained differently in the Bulguksa granites distributed in between Okchon folded belt and Kyongsang sedimentary basin. (2) Trace element abundances show a good discrimination between two goups of granitic rocks. Ba, Sr and V are enriched in Daebo granites, while Zn and Cr are depleted in them. (3) Jurassic granites have quite different Eu anomalies and REE patterns from those of Cretaceous granites: Large negative Eu anomaly in the former and mild or absent Eu anomaly in the latter. The large Eu negative of Cretaceous granitic rocks are interpreted as a differentiated product of fractional crystallization of granitic magma from the upper mantle. Meanwhile, the Daebo plutonic rocks was resulted from the partial melting of subcrustal material or crustal contamination during ascending granitic magma from the mantle. Senario of igneous activities of Mesozoic age in South Korea was proposed based on Kula-Pacific ridge subduction model.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1102-1103
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• 2006

The pretreatment for substrate was carried out in change of gun pressure of $0.5\sim3.5$ bar using wet blasting. The size of $Al_2O_3$ powder was about $50{\sim}150{\mu}m$. As the results, the surface roughness of cemented carbide substrate was improved with increment of gun pressure of wet blasting. A new surface layer was formed and Co particles were uniformly distributed over the entire surface after pretreatment. The adhesion of the pretreated substrate in same PVD-TiAlN film was improved and in approximately $Ra=90\sim120\;nm$ shown the best adhesion value.

• 한국토양비료학회지
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• 제19권2호
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• pp.89-97
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• 1986

영남지역(嶺南地域)에 분포(分布)된 단구지토양(段丘地土壤)의 특성(特性)과 생성(生成)을 구명(究明)하기 위하여 영천(永川)(내륙(內陸)) 및 영일(迎日) (해안(海岸))지역(地域)에서 대표적(代表的)인 단구군(段丘群)을 선정(選定)하여 1, 2차광물(次鑛物)의 조성(助成)과 특성(特性)을 토양생성(土壤生成)과 연관시켜 분석(分析)하여 본 결과(結果)는 다음과 같다. 1. 단구퇴적물(段丘堆積物)의 중세사(中細砂)에 함유(含有)된 중광물(重鑛物)은 5% 이하(以下)이었으나 모재(母材)의 불연속성(不連續性)이 예상되는 토층(土層)에서는 9.8~16.2%로 높았고 경험물(輕驗物) 중(中) 장석류(長石類)의 함량(含量)은 영천지역(永川地域)에서 높은 반면(反面)에 석영(石英)은 영일지역(迎日地域)에서 높았으며 석영(石英)/장석비(長石比)도 모재(母材)의 불연속예상토층(不連續豫想土層)은 단구퇴적물(段丘堆積物)과 구분(區分)되었다. 2. 풍화잔사물(風化殘渣物)의 성숙도지수는 영천지역(永川地域)이 76.7~29.9이었으며 영일지역(迎日地域)은 85.6~67.2로서 고위단구(高位段丘) 일수록 높은 경향이었다. 3. 점토(粘土)의 규반비(珪礬比)는 1.93~2.65로서 낮았고, $Al_2O_2/TiO_2$비(比)와 $Fe_2O_3/Al_2O_3$비(比)를 기준(基準)한 모재(母材)는 산성암류(酸性岩類)에 속하였고 모재(母材)의 불연속성(不連續性)도 구별(區別)되었다. 4. X-선회절분석(線回折分析) 및 시차열분석(示差熱分析)에 의한 점토광물(粘土鑛物)은 Kaolin 및 Illite가 주광물(主鑛物)이었고 일부(一部)는 Vermiculite 및 Vermiculite-Illite중간형광물(中間型鑛物) 등(等)이었으며 모재(母材)의 불연속성(不連續性)이 예상(豫想)되는 영천(永川)의 반천통기층(盤泉統基層)에서는 Kaolin함량(含量)이 증가(增加)되었고 영일(迎日)의 우평통기층(牛坪統基層)에서는 Montmorin계광물(系鑛物)이 다량(多量) 검출(檢出)되는 등(等)으로 단구퇴적물(段丘堆績物)과 구별(區別)되었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.306-308
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• 2007

Poly(ethylene glycol) dimethyl ether (PEGDME)/fumed silica/ 1-methyl -3-propylimidazolium iodide (MPII)/$I_2$ mixtures were used as polymer electrolytes in solid state dye-sensitized solar cells (DSSCs). The contents of MPII were changed and the concentration of $I_2$ was fixed at 0.1 mole% with respect to the MPII. The maximum ionic conductivity was obtained at [EG]:[MPII]:[$I_2$]=10:1.5:0.15. It was supposed that the maximum of ionic conductivities would match with that of cell efficiencies, if the ionic conductivity is a rate determining step in the sol id state DSSCs. However, the maximum composition did not show the maximum solar cell performance, indicating the mismatch between ionic conductivity and cell performance. This suggests that the ionic conductivity may not be the rate controlling step in determining the cell efficiency in these experimental conditions, whereas other parameters such as the electron recombination might play an important role. Thus, we tried to modify the surface of the $TiO_2$ particles by coating a thin metal oxide such as $Al_2O_3$ or $Nb_2O_5$ layer to prevent electron recombination. As a result, the maximum of the cell efficiency was shifted to that of the ionic conductivity. The peak shifts were also attempted to be explained by the diffusion coefficient and the lifetime of electrons in the $TiO_2$ layer.

• KEPCO Journal on Electric Power and Energy
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• 제1권1호
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• pp.115-120
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• 2015

$K_2CO_3$-based dry regenerable sorbents were prepared by spray-drying techniques to improve mass produced $K_2CO_3-Al_2O_3$ sorbents (KEP-CO2P, hereafter), and then tested for their $CO_2$ sorption capacity by a $2,000Nm^3/h$ (0.5 MWe) $CO_2$ capture pilot plant built for Unit 3 of the Hadong thermal power station in 2010. Each of the sample sorbents contained 35 wt.% $K_2CO_3$ as the active materials with various support materials such as $TiO_2$, MgO, Zeolite 13X, $Al_2O_3$, $SiO_2$ and hydrotalcite (HTC). Their physical properties and reactivity were tested to evaluate their applicability to a fluidized-bed or fast transport-bed $CO_2$ capture process. The $CO_2$ sorption capacity and percentage utilization of $K_2CO_3$-MgO based sorbent, Sorb-KM2, was $8.6g-CO_2/100g$-sorbents and 90%, respectively, along with good mechanical strength for fluidized-bed application. Sorbs-KM2 and KT were almost completely regenerated at $140^{\circ}C$. No degradation of Sorb-KM by $SO_2$ added as a pollutant in flue gas was observed during a cycle test.

• 동굴
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• 제45권46호
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• pp.9-31
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• 1996

The Mt. Peakdu is situated in north of the main peninsula, commanding geographically coordinated between longitude W($127^{\circ}$ 15' - $128^{\circ}$ 00') to E($128^{\circ}$ 15'- $129^{\circ}$ 00'), between latitude from S($41^{\circ}$ 15'- $42^{\circ}$ 00') to N($42^{\circ}$ 10'- $42^{\circ}$ 40'). The Manjyang-Gul in Cheju volcanic island is situated in the south of the main peninsula, commanding the Korean Strait, geographically coordinated longitude N($33^{\circ}$ 32' 26") and E($126^{\circ}$ 46' 48"). The quantitative analysis using XRF of volcanic rock samples for the north of Lu- Ming- Feng in Mt. Peakdu Group and the Manjang-Gul in Cheju island was Performed. The major chemical components by group analysis are as follows; Peakdu-Mt. Cheju Peakdu-Mt. Cheju (1) $Na_2O$(3.29Wt% and 3.27Wt%) (2) MgO (3.95Wt% and 6.l5Wt%) (3) $Al_2O_3$((17.64Wt% and 15.l7Wt%) (4) $SiO_2$((50.62Wt% and 50.99Wt%) (5) $P_2O_5$ (0.36Wt% and 0.30Wt%) (6) $K_2O$ (1.37Wt% and 1.04Wt%) (7) CaO (8.56Wt% and 8.06Wt%) (8) $TiO_2$ (2.37Wt% and 2.l5Wt%) (9) MnO (0.llWt% and 0.l6Wt%) (10) $Fe_2O_3$(9.l2Wt% and 12.56Wt%) The Group analysis data were compared in the relation within the age of formation for $0.16{\pm}0.08Ma$ in Mt. Peakdu Group, and $0.42{\pm}42Ma$ or $0.42{\pm}42Ma$ in Cheju island for K-Ar age. The crystal structure are mixed crystal of monoclinic, hexagonal and triclinic system in Mt. Peakdu Group and mixed structure of triclinic and cubic system in Cheju volcanic island.ic island.

• 한국군사과학기술학회지
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• 제7권2호
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• pp.81-87
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• 2004

Semiconductor thick film gas sensors based on tin oxide are fabricated and their gas response characteristics are examined for four simulant gases of chemical warfare agent (CWA)s. The sensing materials are prepared in three different sets. 1) The Pt or Pd $(1,\;2,\;3\;wt.\%)$ as catalyst is impregnated in the base material of $SnO_2$ by impregnation method.2) $Al_2O_3\;(0,\;4,\;12,\;20\;wt.\%),\;In_2O_3\;(1,\;2,\;3\;wt.\%),\;WO_3\;(1,\;2,\;3\;wt.\%),\;TiO_2\;(3,\;5,\;10\;wt.\%)$ or $SiO_2\;(3,\;5,\;10\;wt.\%)$ is added to $SnO_2$ by physical ball milling process. 3) ZnO $(1,\;2,\;3,\;4,\;5\;wt.\%)$ or $ZrO_2\;(1,\;3,\;5\;wt.\%)$ is added to $SnO_2$ by co-precipitation method. Surface morphology, particle size, and specific surface area of fabricated sensing films are performed by the SEM, XRD and BET respectively. Response characteristics are examined for simulant gases with temperature in the range 200 to $400^{\circ}C$, with different gas concentrations. These sensors have high sensitivities more than $50\%$ at 500ppb concentration for test gases and also have shown good repetition tests. Four sensing materials are selected with good sensitivity and stability and are fabricated as a sensor array A sensor array Identities among the four simulant gases through the principal component analysis (PCA). High sensitivity is acquired by using the semiconductor thick film gas sensors and four CWA gases are classified by using a sensor array through PCA.