• Journal of the Speleological Society of Korea
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• v.19 no.20
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• pp.29-62
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• 1989

Cheju Island, which was formed by volcanic activity, is an oval in its shape with the major axis 80km and the minor axis of 40km. The island holds in its heart Mt. Hanala rising 1,950m above the sea. Petrological study of this volcanic island has been made actively by Sang-Man Lee, Chong-Kwang Won and Moon-Won Li. The chronological measurements of the island by Chong-Kwan Won and Moon-Won Lee showed that it is composed of Sanbangsan trachytes and Backlokdam trachytes(25,000 year ago). These reports are based on the chemical analysis and the rediometric chronological measurements on the ground. However, there has been no reports about the inside of caves. We made an (composition) analysis of the inside of Manjang Cave by the fundamental parameter method in X-ray fluorescence spectrometry. The fundamental parameter method in X-ray fluorescence spectrometry is nondestructive analysis. and it enables us to make the values processed by a computer. The results obtained by this methods are as follows: SiO$_2$(49％), $Al_2$O$_3$(17％), Fe$_2$O$_3$(13％), CaO(8.1％), MgO(5.5％), Na2O(3.6％), TiO$_2$(2.1％), $K_2$O(0.86％), P$_2$O$_{5}$(0.28％), and MnO(0.20％) respectively. The data obtained by the fundamental parameter method in X-ray fluorescene was compared with the data provided by Chong-Kwan Won and Moon-Won Lee. Our measurement was made by K-Ar-method in cooperation with T. ITAYA. The samples are of 30,000-420,000 years ago. The composition of the values of our underground analysis with the existing values obtained by the analyses on the ground produced new data about Cehju volcanic island.d.

• Economic and Environmental Geology
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• v.32 no.3
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• pp.227-236
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• 1999

The Daeyou pegmatite is located at the central westerm part of the peninsula. Geology of the mine area consists mainy of pre-Combrian granite gneiss and leucoratic gneiss which are intruded by Mesozoic granites. The pegmatite deposits occur within granite gneiss. Most of pegmatites contain quartz, perthite, microcline-perthite, microcline, sodic plagioclase and tourmaline as dominant minerals with accessory minerals of mica (muscovite, biotite, sericite)and pyrite. Tourmaline occurs as four types: 1) unaltered single crystals, 2) patially sericitized grains bordered by sericite assemblage, 3) tourmaline intergrown with feldspar and qurtz grains, and 4) tourmaline introduced veinlet/ On the basic of optical, X-ray diffraction and chemical analysis, the composition of tourmaline mostly falls on the schorl-elbaite join, in the composition of tourmaline mostly falls on the schorl-elbraite join, in the composition of schorl end member from 0 to about 50%. In spite of the different occurrences, chemical composition of tourmaline shows the limited ranges as follows: $SiO_{2}$ (34.53~35.01 wt.%), $Al_{2}O_{3}$ (33.58~34.26wt.%), FeO (13.73~14.17wt.%), $Na_{2}O$ (1.60~1.72wt.%), MgO (0.56~0.72wt.%), MnO (0.12~0.18wt.%), CaO (0.02~0.06wt.%), $K_{2}O$(0.02~0.03wt.%) $TiO_{2}$ (0.02~0.05wt.%) and $Cr_{2}O_{3}$ (0.02~0.03wt.%). K-Ar ages of the muscovite and sericite fall between 1010$\pm$15 and 1074$\pm$16Ma and between 161.56$\pm$3.09 and 161.67$\pm$Ma, respectivrly. This means that hydrothrmal alteration occurred during middle Jurassic, whereas the pegmatite was initally formed during the late proterozoic age.

• Journal of the Speleological Society of Korea
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• v.21 no.22
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• pp.17-56
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• 1990

Cheju Island, which was formed by volcanic activity, is an oval in its shape with the major axis of 80km and the minor axis of 40km. The island holds in its heart Mt. Hanla rising 1,950m above the sea. Petrological study of this volcanic island has been made actively by Sang-Man Lee, Chong-Kwan won and Moon-Won Lee. The chronological measurements of the island by Chong-Kwan Won and Moon-Won Lee showed that it is composed of Sanbangsan trachytes and Backlokdam trachytes(25,000 year ago). These reports are based on the chemical analysis and the rediometric chronological measurements on the ground. However, there has been no reports about the inside of caves. We made an (composition) analysis of the inside of Manjang Cave by the fundamental parameter method in X-ray fluorescence spectrometry. The fundamental parameter method in X-ray fluorescence spectrometry is nondestructive analysis, and it enables us to make the values processed by a computer. The results obtained by this methods are as follows : SiO$_2$(49％), $Al_2$O$_3$(17％), Fe$_2$O$_3$(13％), CaO(8.1％), MgO(5.5％), Na$_2$O(3.6％), TiO$_2$(2.1％), $K_2$O(0.86％), P$_2$O$_{5}$(0.28％), and MnO(0.20％), respectively. The data obtained by the fundamental parameter method in X-ray fluorescence was compared with the data provided by Chong-Kwan and Moon-Won Lee. Our measurement was made by K-Ar-method in cooperation with T.ITAYA. The samples are of 30,000～420,000 year ago. The composition of the values of our underground analysis with the existing values obtained by the analyses on the ground produced new data about Cheju volcanic island.d.

• Journal of the Speleological Society of Korea
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• v.45 no.46
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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.

• Journal of the Speleological Society of Korea
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• v.34 no.35
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• pp.32-42
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• 1993

The Paektu-san mountains are geographically situated in the Korea strait to the north of the main peninsula, coordinated between the longitudes of W(127$^{\circ}$15'~128$^{\circ}$00')and E(128$^{\circ}$15'~129$^{\circ}$00'), and between the latitudes of S(41$^{\circ}$15'~42$^{\circ}$00') and N(42$^{\circ}$10'~42$^{\circ}$40'). The volcanic group of the Paektu-san mountains can be devided into 2 main kinds of volcanos by the method investigation, The ashes are mainly made of tremolite, trachte, basalt and pumice, or, a little quartz, labradorite and volcanic glass. These sorts, ratios and forms of the rocks are respectively similar. The Haeven lake is surrounded by 19 peaks. The central volcanic cone is a secant cone in shape, with an altitude of the 1800m to 2749,2m (Chang-kun-bong), an average diameter of 10km, and a shape of an ellipse seen high from the plane. They say there were several eruptions in 1668, 1700 and 1702 A. D. The crystal structure of the rock sample collected at the cave of Mt. Paektu-san is monoclinic. The quantitative analysis of the rock samples in the cave is done by using XRF this time. The chemical compositions by XRF fundamamental parameter analysis is : SiO$_2$: 50.72Wt%, TiO = 2.422Wt%, $Al_2$O$_3$= 17.65Wt%, Fe$_2$O$_3$= 9.371Wt%, CaO = 8.711Wt%, MgO = 4.l19Wt%, MnO = 0.l15Wt%, $K_2$O = 1.369Wt%, Na$_2$O : 3.028Wt% and P$_2$O$_{5}$ = 0.365Wt%. The K-Ar age of the rock sample is also determined to be 0.16Ma. This paper describes some problems experienced in dating young volcanic rocks, and then discusses chemical compositions, X-ray fluorescence analyses and the age of the formation of a lava tunnel such as in Mt. Paektu-san.n.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.89-97
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• 1986

To clarify the soil characteristics and genesis of the clayey terrace soils in Yeongnam area, the study were carried out with 9 typifying pedons of toposequential terrace soils in Yeongcheon (inland area) and Yeongil (coastal area) region. The results of soil genesis oriented investigations on soil mineralogical compositions and weathering characteristics were summarized as follows; 1. The contents of heavy minerals contained in sand fraction of the terrace soils were less than 5%, but the content in soil layers considered to be originated from other than terrace deposits had 9.8-16.2%. The content of feldspars in light minerals were higher in Yeongcheon sequence while the Yeongil sequence were characterized by having higher content in quartz. The ratios of quartz/feldspars in the soil layers where expecting lithological discontinuity, were different from that of terrace deposits. 2. The resistate index of maturity ranged around 76.7-29.9 in Yeongcheon area and around 85.6-67.2 in Yeongil area. The indices increased with the elevations of terraces. 3. The molar ratios of $SiO_2/Al_2O_3$ in clay fraction were around 1.93-2.65. The parent materials of the terrace deposits judged by the ratios of $Al_2O_3/TiO_2$ and $Fe_2O_3/Al_2O_3$ were considered to be the felsic materials. 4. The compositions of clay minerals detected by X-ray diffractogram and D.T.A. thermogram were dominated by kaolin and illite with subsidiary minerals of vermiculite, quartz, vermiculite intergrading to illite etc. It was distinguished from terrace deposits that by having higher amount of kaolin and montmorin minerals in the substrata of Bancheon soils in Yeongcheon area and Upyeong soils in Yeongil area, respectively.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.108-125
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• 2013

This study examined the actual reconstruction drawing, composite mineral, particle size and property test, fine organic matters, color differences and main ingredients of the earthen mold excavated in Dongcheon-dong, Gyungju. The cross-section of the inner mold and outer mold divides into inside (1st layer) and outside (2nd layer), with organic matters mixed outside. The cross-section has been altered due to heat and form removal agent. X-ray analysis revealed that the layer was made of minerals with high transmissivity and only quartz particles were observed through a polarizing microscope. The inside of cross-section in SEM observation identified enlarged air gap, with crack developed in the center, but no changes observed on the outside. The particle size of the composites is almost the same for the inner mold and outer mold and is silt clay loam. The ratio between silt clay and silt clay loam was about 2.7:1 and 2.9:1 respectively. In the property test, the density and absorption rate of inner mold and outer mold were similar, but porosity was different, with inner mold of 27.36% and outer mold of 31.09%. The color difference of cross-section seems to have been caused by the spread of soot on the 1st layer surface for removal of form or by the covering of ink to protect the 1st layer. Composite mineral analysis revealed the same composition for the inner mold and outer mold, except for the magnetite that was detected in the inner mold alone. As for the main ingredient analysis, the average content of $SiO_2$ was 71.64% and that of $Al_2O_3$ was 14.59%. As for the sub-ingredients, $Fe_2O_3$ was 4.51%, $K_2O$ 3.06%, $Na_2O$, MgO, CaO, $TiO_2$, $P_2O_5$ and MnO was less than 2%.

• Korean Journal of Heritage: History & Science
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• v.41 no.1
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• pp.5-19
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• 2008

Thirty six samples of Western asia glass vessel shards which were excavated from South Mound of Hwangnamdaechong were each measured for thickness, pore size and specific gravity and analyzed for ten major compositions and thirteen trace elements. The glass samples with colorless, greenish blue and dark purple blue were well classified by principal component analysis(PCA). All glass shards of Hwangnamdaechong belonged to Soda glass system ($Na_2O-CaO-SiO_2$) which have the range of 14~17% $Na_2O$ and 5~6% CaO. The corelation coefficients of (MgO, $K_2O$) and (MnO, CuO) showed above 0.90. The concentrations of thirteen trace elements apparently differentiated from colorless, greenish blue and dark blue glasses. We found that thirteen trace elements were very important indices for studying raw material of glass and the origin of glass making. Colorless glass : The specific gravity is $1.50{\pm}0.04$. Circle or oval circle pores are observed with regular direction in internal zone and the longest one is about 0.35 mm. The raw material of sodium must be the plant ash because sodium glasses contain HCLA(High CaO, Low $Al_2O_3$) and HMK(high MgO, high $K_2O$) and suggested to Sasanian glass. The total amount of coloring agent of colorless glass is below 1 % which is too small to attribute to the color. Greenish blue glass : The specific gravity is $1.58{\pm}0.04$. The fine pores which are 0.1~0.2mm are dispersed in internal zone. Sodium glasses are distributed to HCLA and HMK. Therefore the greenish blue glass also have used plant ash for raw material of sodium with the same as colorless glass. It was also suggested to the glass of Sasanian. The total amount of coloring agent of greenish blue glass is about 4% under the influence of working MnO, $Fe_2O_3$ and CuO. Dark purple blue glass : The specific gravity is $1.48{\pm}0.19$. There are rarely pores in internal zone. They are distributed to HCLA and LMK(Low MgO, Low $K_2O$) and suggested to Roman glass. The raw material of sodium is estimated to natron. The total amount of coloring agents of greenish blue is about 3% by $Fe_2O_3$ and CuO. These studies for western asia glass shards from South Mound of Hwangnamdaechong could be used in the future as the standard data which could be compared with those of other several graves in Korea and dispersed in foreign areas.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.108.1-108.1
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• 2010

분류층 가스화기는 석탄과 산소(공기) 및 수증기가 반응하여 $1200{\sim}1600^{\circ}C$의 고온, 20~60기압의 고압에서 작동되어 합성가스를 생성하며 합성가스에 포함된 입자 및 황화합물 등을 정제설비를 통하여 정제 후 발전 및 화학원료로 사용한다. 석탄가스화 중 석탄에 포함된 대부분의 회분은 용융슬래그 형태로 가스화기 벽면을 따라 흘러 내려 가스화기 하부의 냉각수조에서 급랭되어 배출된다. 이때 용융슬래그의 원활한 배출을 위해서는 일정범위의 점도를 유지하는 것이 필요하다. 슬래그의 점도는 가스화기 온도 및 Ash의 조성에 따라 크게 변하며 가스화기 설계 및 운전 시 매우 중요한 변수이다. 따라서 최적의 설계 및 운전을 위해서는 Ash의 점도예측이 중요하며, 분류층 가스화기내부에서 Ash 점도 예측을 위한 DooVisco 프로그램을 개발하였다. DooVisco는 가스화기 내부에서 슬래그 용융온도 및 온도별 점도, 가스화기 최소 운전온도 및 석회석 투입 효과 분석뿐만 아니라 석탄의 혼합 사용 시의 특성 예측도 가능하도록 개발되었다. DooVisco는 슬래그 주요 4성분인 SiO2, Al2O3, CaO, FeO 성분에 대한 Phase Diagram을 이용하여 1차적으로 슬래그용융온도(Liquidus Temperature)를 예측하고, 주요 4 성분 외에 Na2O, MgO, K2O, TiO2 등을 고려한 Kalmanovich Model을 이용하여 점도를 예측한다. 최종적으로 슬래그 용융온도와 점도를 활용하여 분류층 가스화기 운전가능 온도범위를 예측한다. 개발된 DooVisco를 활용하여 300MW급 실증 IGCC 플랜트에 사용가능성이 있는 석탄을 대상으로 슬래그의 용융온도 및 점도 등을 예측하였으며 최적 운전을 위한 슬form점도 조절용 Flux인 석회석 투입량 등을 평가하였다. 평가 결과 슬래그 용융온도가 $1700^{\circ}C$ 이상으로 석회석 투입이 필요하다고 판단되었다. 약 가스화기 내부 온도를 $1500^{\circ}C$ 정도에서 원활한 운전을 위해서는 석탄 대비 약 10% 내외의 석회석 투입이 필요할 것으로 평가되었다. DooVisco는 분류층 가스화기 설 계시 가스화기 최적 운전 온도 설정 및 Flux 투입필요성, 종류, 투입량 선정에 활용될 수 있을 뿐만 아니라 플랜트 운전시 석탄의 탄종 적합성 등을 판단하는데 활용될 수 있을 것이라 판단된다.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.591-598
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• 2023

In this study, the corrosion resistance by salt spray was evaluated using A6061-T6 for an electric vehicle battery pack case coated with an organic/inorganic hybrid solution. The lowest curing temperature of 190 ℃ resulted in significant corrosion and pitting. Meanwhile, no corrosion was observed in the coated specimens at 210 ℃ and 230 ℃ except at 210 ℃ - 6 min and 8 min. The surface of the as-received coating specimen observed by FE-SEM exhibited streaks and dents in the rolling direction, but the coating surface was clean. On the 190 ℃ - 6 min coating specimen, which had a lot of corrosion, rolling streaks spread, and dents were caused by corrosion. The 200 ℃ - 12 min coating specimen did not show corrosion, but it showed an etched surface. In the line profile, Si, the main component of the coating solution, was detected the most, and Ti was also detected. In the coating specimens with salt spray, O increased and Si decreased, regardless of corrosion. The peeling rate by adhesion evaluation was 26 - 87% for the 190 ℃ coating specimen, 4 - 83% for the 210 ℃ coating specimen, and 94 - 100% for the 230 ℃ coating specimen. The optimal curing conditions for the coating solution used in this study were 210 ℃ for 10 min.