• Economic and Environmental Geology
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• v.27 no.4
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• pp.387-396
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• 1994

Mineralogical and geochemical studies on gold-bearing quartz veins and wallrock from the Mugeug mine were carried out in order to investigate the variation of mineralogical composition and the geochemical behavior of elements with distance from the gold-bearing quartz veins. Gold-bearing quartz veins occur in early Cretaceous medium- to coarse-grained biotite granite. The unaltered wallrock is composed mainly of quartz, plagioclase, orthoclase, microcline, biotite and hornblende with accessory minerals of sphene and apatite. Mineralogical changes in altered wallrock around the gold-bearing quartz veins were observed as follows; 1) biotite and hornblende altered into chlorite, and next to sericite, 2) plagioclase, orthoclase and microcline altered into sericite, and 3) calcite and quartz introduced into wallrock. Contents of $K_2O$, Rb, Cs, Au, As and Sb in altered wallrock increase, whereas those of $Na_2O$, CaO, Ba, and Sr decrease with proximity to the gold-bearing quartz veins. The loss on ignition also increases with the increase of alteration mineral. The width of primary dispersion increases in order $Au=SiO_2<As=Cs=Rb<K_2O=Sb$ and $MnO<Na_2O=CaO=Ba<Sr$. The sericitization index, $K_2O/(K_2O+Na_2O)$, is an important indicator to interpret the degree of alteration at the Mugeug mine, which is more than 0.8 in strongly and moderately altered granite, 0.5~0.8 in wea altered granite, and less than 0.5 in unaltered granite. Alteration indices for major and trace elements, and the ratio of Rb/Sr are also useful to discriminate alteration zones.

• Macromolecular Research
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• v.11 no.4
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• pp.260-266
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• 2003

Ethylene vinyl acetate (EVA)/clay nanocomposites were synthesized by blending a solution of ethylene vinyl acetate copolymer containing 12% vinyl acetate abbreviated as EVA-12 in toluene and dispersion of dodecyl ammonium ion intercalated montmorillonite (l2Me-MMT) in N,N-dimethyl acetamide (DMAc). X-ray patterns of sodium montmorillonite ($Na^+$-MMT) and 12Me-MMT exhibited $d_{001}$ peak at $2{\theta}=7.4^{\circ}$ and $2{\theta}=5.6^{\circ}$ respectively; that is, the interlayer spacing of MMT increased by about 0.39 nm due to intercalation of dodecyl ammonium ions. The XRD trace of EVA showed no peak in the angular range of $3-10^{\circ}(2{\theta})$. In the XRD patterns of EVA/clay hybrids with clay content up to 6 wt% the basal reflection peak of 12Me-MMT was absent. leading to the formation of delaminated configuration of the composites. When the 12Me-MMT content was 8 wt% in the EVA-12 matrix, the hybrid revealed a peak at about $2{\theta}=5.6^{\circ}$, owing to the aggregation of aluminosilicate layers. Transmission electron microscopic photograph exhibited that an average size of 12-15 nm clay layers were randomly and homogeneously dispersed in the polymer matrix, which led to the formation of nanocomposite with delaminated configuration. The formation of delaminated nanocomposites was manifested through the enhancement of mechanical properties and thermal stability, e.g. tensile strength of an hybrid containing only 2 wt% 12Me-MMT was enhanced by about 36% as compared with neat EVA-12.

• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.55-65
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• 2004

We have used the Naju Oryang-dong Kiln, the Jar coffin producing center from the 5th to early 6th century A.D. found for the first time in Korea in 2002 and conducted trace element analysis of Jar coffin objects excavated in Jar coffin the old tomb area formed mainly around Yeongsan valley, the consuming area of the same period as our main research objects. For this analysis, we have used both the NAA method, the non-parametric micro-minerals analysis. In order to compare and verify these remains, we have used the results from the analysis on the Jar coffin remains in the Mandong remains, Jeonbuk district. We have quantitatively analyzed 17 types of elements from the Jar coffin remains sample to allow for various and correct analysis. With their results, we could find out that the jar coffins made in Oryang-dong kiln teo are statistically identical to those in Daean-ri Old tomb/Shinchon-ri 9th old tomb, Okya-ri old tomb, and Banam-Old tomb. Also, we can conclude that there is a high possibility that ongwans produced from Oryang-dong kiln being used in Daean-ri Old tomb/Shinchon-ri 9th old tomb, Okya-ri old tomb, and Banam-Old tomb was distributed through some form of trade. On the other hand, we could obtain other analysis results that jar coffins excavated and investigated in the Mandong remains and Ithe npyong Old tomb were likely from other Jar coffin kilns through trade and distribution.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.107-114
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• 2005

모발은 고통 없이 검체를 채취할 수 있고 저장이 간편하며 인체에 장기간 축적된 미네랄과 중금속함량을 측정하는데 매우 적당한 재료이다. 그러므로 45세 전후의 남자두발을 검체로 하여 상습흡연자(3년 이상 하루 1갑 이상흡연자)와 비흡연자 그리고 청소년을 대상으로 15종의 영양원소와 8종의 독성원소, 그리고 15종류의 기타원소를 조사하여 이들 미네랄 함량의 기초 자료를 제시하고자 하였다. 총 38종류의 원소분석은 정확도를 기하기 위하여 Trace elements, Inc (Dallas, Tx, USA)사에 의뢰하였으며, 이곳에서는 유도결합 플라즈마 질량분석기를 사용하여 분석하였다. 결과는 흡연자가 비 흡연자에 비하여 영양원소는 대체적으로 비슷하였으나 특히 Mg(P<0.05)와 Cu함량이 각각 3.9와 2.4 ppm의 차이로 흡연자가 낮았고, 독성원소는 Hg(P<0.001)가 0.16과 0.31 ppm으로써 0.15 ppm 차이로 흡연자가 높은 특징을 보였는데, 이것은 최대허용치인 0.18 ppm과 비교해 보았을 때 약 2배 이상 초과하는 것이 였엇다. 이러한 원인들은 흡연에 있다고 볼 수 있으며, Hg의 중독증상은 중추신경 장애와 의욕상실, 만성피로를 일으킬 수 있으며 미나마타병의 원인물질로 알려져 있다. 한편,청소년과 성인에 있어서 영양원소의 함량은 Cu, P, Mn, B가 각각 3.2, 2.1, 0.016, 0.03 ppm의 차이로 성인에서 높았다. 그러나 생리활성물질인 Ca, Na, K은 각각 55.3, 15.2, 9.0 ppm의 차이로 청소년에서 높았는데, 이것은 성장기 청소년들에게 있어서의 특징이라고 할 수 있다. 독성원소는 Hg가 0.16 ppm으로 성인에서, Cd는 0.01 ppm으로 청소년에서 높았지만 각각 최대 허용치인 0.18과 0.014 ppm 이하였다.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.232-239
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• 1989

Three types of Korean strawberries, Gardian cultivated in vinyl house, Gardian cultivated on the field and Bogyo, at early variety, on the field were harvested after $10{\sim}34$ days from falling of flowers to investigate the chemical changes of fruits during maturing. The initial pH range after 10 days from falling of flowers was $4.13{\sim}4.28$, which was decreased to $3.40{\sim}3.49$ with maturing. The total acid was steadily increased for 26 days and then decreased thereafter. Vitamin C, not detected until 14 days, was gradually increased to $15.83{\sim}24.90mg%$ in 34 days. Reducing sugar content was increased for 24 days and then decreased, while total sugar, glucose and fructose were generally increased during maturing. Xylose was detected a little. For minerals, potassium was measured the highest value, followed by magnessium, and sodium. A trace amount of manganese, zinc and copper were detected. The strawberries had the content range of $6.00{\sim}24.60mg%$ of methyl alcohol and $6.00{\sim}24.40mg%$ of ethyl alcohol.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.390-395
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• 2002

Concentrations of minerals (Ca, K, Mg, Na, Se, Zn, Fe, and Mn) in 50 different Korean foodstuffs were determined through neutron activation analysis. To check the accuracy of this method, the U.S. NIST standard reference materials were analyzed. Anchovy, sesame, perilla, and laver were found to contain relatively higher concentrations of Ca, Mg, Fe, and Zn than the other foodstuffs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.825-834
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• 2021

This study was conducted to identify the food components and nutrition value of major fish roes on the market in Korea. The proximate compositions of the roes were 60.02-82.85% moisture, 14.61-29.21% protein, 1.24-14.59% lipid and 0.88-1.78% ash. The major total amino acids in the roes were glutamic acid, leucine, aspartic acid, lysine, and alanine. The major fatty acids were 22:6n-3 (docosahexenoic acid, 9.37-32.68%), 16:0 (5.96-21.39%), 18:1n-9 (12.64-25.30%), and 20:5n-3 (eicosapentaenoic acid, 3.79-16.99%). The mean major-mineral levels were phosphorus (291.63 mg/100 g edible portion), potassium (271.00 mg), sodium (175.86 mg), calcium (24.02 mg), and magnesium (22.15 mg). The mean trace-mineral levels were zinc (7.75 mg), iron (3.68 mg), and copper (0.81 mg). The results suggest that these fish roes are good sources of proteins, amino acids, n-3 fatty acids and minerals.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.173-182
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• 2022

Dongsuak crater, located in the mid-mountainous region of Jeju Island, is located at an altitude of about 700 m, and the newly discovered Dongsuak spinel peridotites was enclosed in Dongsuak alkaline basalt. The Dongsuak spinel peridotites are composed of olivine, orthopyroxene, clinopyroxene, and spinel with porphyroclastic texture under the an equilibrium state. The variations of mineral major and trace compositions indicates that the Dongsuak spinel peridotites originate at depth from 66 to 88 km under an equilibrium temperature of about 960℃~1068℃. The Dongsuak spinel peridotites have been undergone about 1~3% fractional melting. The LREE-enriched characteristics indicate that the Dongsuak spinel peridotites have been undergone cryptic metasomatism by silicate melt without new minerals.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.259-275
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• 2023

Pan African granitoids of Kaiama is comprised of K-feldspar rich granites, porphyritic granites, and granitic gneiss that are intruded by quartz veins and aplitic veins and dykes which trend NE-SW. In order to establish the geochemical signatures, petrogenesis, and tectonic settings of the lithological units, petrological, petrographical, and geochemical studies was carried out. Petrographic analysis reveals that the granitoids are dominantly composed of quartz, plagioclase feldspar, biotite, and k-feldspar with occasional muscovites, sericite, and opaque minerals that constitute very low proportion. Major, trace, and rare earth elements geochemical data reveal that the rocks have moderate to high silica (SiO₂=63-79.7%) and alumina (Al₂O₃=11.85-16.15) contents that correlate with the abundance of quartz, feldspars, and biotite. The rocks are calc-alkaline, peraluminous (ASI=1.0-<1.2), and S-type granitoids sourced by melting of pre-existing metasedimentary or sedimentary rocks containing Al, Na, and K oxides. They plot dominantly in the WPG and VAG fields suggesting emplacement in a post-collisional tectonic setting. On a multi-element variation diagram, the granitoids show depletion in Ba, K, P, Rb, and Ti while enrichment was observed for Th, U, Nd, Pb and Sm. Their rare-earth elements pattern is characterized by moderate fractionation ((La/Yb)_N=0.52-38.24) and pronounced negative Eu-anomaly (Eu/Eu^*=0.02-1.22) that points to the preservation of plagioclase from the source magma. Generally, the geochemical features of the granitoids show that they were derived by the partial melting of crustal rocks with some input from greywacke and pelitic materials in a typical post-collisional tectonic setting.

• Journal of The Geomorphological Association of Korea
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• v.27 no.3
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• pp.105-121
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• 2020

There has been a lot of controversy over the claim that ancient characters were engraved on a stone plane collected near the Samsin Mountain in Hadong-gun, and that it was used as an altar based on the contents on the stone. The importance of the role of geoscience in prehistoric petroglyph research was presented through analysis and comparison with representative domestic petroglyphs. First, by examining the geological formation process of the collected stone objects, it proved that prehistoric actions were not applied. Second, as a result of comparative analysis from the viewpoints of human geography and topography with representative petroglyphs in Korea, it is unreasonable to argue that the stone was made for an altar. Third, it is considered that among the ancient characters under debate, the straight line indicates a cleavage of carbonate minerals, and the curved shape results from the growth of lichens. Finally, we propose that reproducing the lines found on the stone was impossible by using ancient techniques, and that there was no trace of any artificial actions applied to the spots considered to be curved characters. As shown in such research cases, the results of petroglyph research will have high reliability, if research by experts in each field continues after the geoscientific basis is secured. In this respect, the contribution of Earth science to cultural assets and archeology is expected to increase in the future.