• Food Science and Biotechnology
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• v.15 no.2
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• pp.220-226
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• 2006

Component having antioxidant activity on lard during heating was separated from hexane extract of spinach, and its characteristic chemical structure was speculated through nuclear magnetic resonance spectroscopy, liquid chromatography-mass spectrometry, and Fourier transform infrared spectrophotometry. Lard was heated with hexane-, ethyl ether-, ethyl acetate-, or ethanol extract of spinach at $180^{\circ}C$ for 20 hr. Hexane extract of spinach, having highest antioxidant activity on lard during heating, was fractionated by silicic acid column chromatography (SACC), and SACC fractions having higher antioxidant activity on lard during heating were further separated by thin layer chromatography (TLC). Isolated compound from SACC fractions of hexane extract of spinach by TLC had sugar moieties and benzene ring along with hydroxy, carbonyl, and alkyl groups in the structure.

• Journal of the Korean Chemical Society
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• v.28 no.4
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• pp.244-250
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• 1984

Separation and identification of the polycyclic aromatic compounds (PAC) from pyrolysis products of cellulose and lignin were performed using a combination of acid-base solvent partitioning and silicic acid column chromatography with fused-silica capillary column gas chromatography/ mass spectrometry. Sixteen PAC were positively identifited by retention indices and mass spectra data. Both materials produced the same kinds of PAC. But lignin produced much more PAC than cellulose. Almost no highly carcinogenic heterocyclic PAC containing nitrogen and sulfur were produced.

• Journal of the Mineralogical Society of Korea
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• v.9 no.2
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• pp.82-92
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• 1996

The coarse-grained (0.05∼0.2mm) zeolites occur as the single-crystal cement in the sandstones of the Chunbuk Formation in the Pohang area. The zeolite cements unusually consist of the composite phases of heulandite and clinoptilolite and in a crystal. The zeolite crystals show chemical zoning ranging from 3.56 to 4.10 in Si/(Al+Fe), and tend to become continuously more silicic and alkalic from the margin toward inside of the crystal. The DTA and high-temperature XRD analyses also show complex patterns of both zeolites. Such a composite crystal showing chemical zoning and complex thermo-chemical behaviors indicates that heulandite and clinoptilolite are constituting a solid solution resulted from the coupled substitution of K+Si4+=Ca2+Al3+.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2000.12a
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• pp.54.1-54
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• 2000

한국 남해안 완도지역에 자생하는 미역 (Undaria pinnatifida)의 부위별 지방산조성 특성을 계통적으로 분석코자 미역의 부위별 지방질 및 지방산 조성을 silicic acid 컬럼과 기체-액체 크로마토그래피 분석하였다. 총지방질 함량을 비교해 볼 때 엽상부 3.37%, 포자엽 4.59% 및 줄기 2.50%였으나, 엽상부는 총 포리엔산과 linolenic acid(18:3, n-3), stearidonic acid(18:4, n-3), eicosapentaenoic acid(20:5, n-3) 및 docosahexaenoic acid(22:6, n-3)와 같은 n-3계열의 포리엔산의 조성비율이 높았다. 즉 총 포리엔산과 n-3계열의 포리엔산 조성비율을 볼 때 엽상부는 44.18% 및 29.69%였고, 포자엽은 23.63% 및 5.58% 줄기는 26.66% 및 7.37%였다. 한편 중성지방질, 당지방질 및 인지방질의 n-3 포리엔산의 함량을 볼 때 엽상부는 22.40%, 35.82% 및 3.53%로 다른 부위에 비하여 현저하게 높았으나, 줄기는 5.26%, 9.51% 및 2.37%였고 포자엽은 4.49%, 8.01% 및 2.14%로 가장 낮았다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.583-590
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• 1990

Free and esterified forms of provitamin D in 30-day-old mele rat skin were isolated and quantitated using silicic acid column chromatography and high-performance liquid chromatography(HPLC) systems. Two forms of free provitamin D(cholesta-5, 7-dien-$3{\beta}$-ol and cholesta-5, 7, 24-trien-$3{\beta}$-ol) and at least thirteen esterified forms of provitamin D were isolated. The average total concentration of provitamin D in the whole skin was $6,056ng/cm^2$. The skin contained $846ng/cm^2$ of free provitamin D and $5,209ng/cm^2$ of esterified provitamin D. The proportion of esterified provitamin D in the skin was 86%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.4
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• pp.376-380
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• 1991

The contents of total lipids from Korean marine benthic algae Miyeok(Undaria pinnatifida) and Pare(Enteromorpha compressa)were 1.8% and 0.7% on the dry basis, respectively. They were fractionated by silicic acid column chromatography and identified by gae liquid chromatography. The ratios of neutral lipids, glycolipids and phospholipids in total lipids were 3.5 : 74.1 : 22.4 in Miyeok and 33.1 : 48.4 : 18.5 in Pare. Total fatty acids in Miyeok and Pare were composed of 28.5 and 33.2% of saturates, 9.8 and 10.8% of monoenes, 61.7 and 56.0% of polyenes, respectively and the polyunsaturated acid was the most predominent component. $\omega$-3 polyunsaturated fatty acids were C18:4(15.9 and 17.1%) and C20:5(10.6 and 6.0%).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.113-114
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• 2017

In this study, the change of composition of cement hardened at high temperature through XRD was observed. The specimen was made of cement paste and the heating rate condition was applied at rapid thermal annealing (10.0℃ / min). The decrease of calcium hydroxide was not confirmed, but the calcium carbonate tended to be impossible or decreased after 800℃. Calcium silicate and larnite were observed to increase with increasing temperature. It is considered that silicic acid, which is a stable structure due to the decomposition of calcium silicate, is changed into a phase such as lime.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.330-330
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• 2003

Several volcanics are found within the Tertiary sedimentary basins, southeastern part of Korea. The sedimentary basins have been interpreted to have formed in the framework of separation of the East Sea. The volcanics are Eocene or Early and Middle Miocene in ages, showing a distincetve chronological gap, and show mafic and silicic (bimodal) in composotion. The Miocene volcanics were regionally and stratigraphically grouped into two varieties along the Hyeongsan fault; younger volcanics (13.6-15.2 Ma, K) from the north of the fault, erupted after the opening of the East Sea, and older volcanics (16.2-21.1 Ma) from the south of the fault. (omitted)

• YAKHAK HOEJI
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• v.27 no.1
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• pp.29-36
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• 1983

Shogaol, one of the main pungent principles of the rhizome of Zingiber officinale, Roscoe, was biodegraded by Aspergillus niger to produce two main metabolites. The crystalline metabolite obtained after silicic acid column chromatography was proved to be 1-(4-hydroxy-3- methoxyphenyl)decan-10-ol-3-one. The oily metabolite obtained after prolonged fermentation was 1-(4-hydroxy-3-methoxyphenyl)-decan-3, 10-diol. The results suggest that shogaol should be biodegraded to 1-(4-hydroxy-3-methoxyphenyl)-dec-4-en-10-ol-3-one or to 1-(4-hydroxy-3-methoxyphenyl)-decan-3-one, and to 1-(4-hydroxy-3-methoxyphenyl)-decan-10-ol-3-one then to 1-(4-hydroxy-3-methoxyphenyl)-decan-3, 10-diol and finally to carbon dioxide and water.

• Journal of Ceramic Processing Research
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• v.13 no.spc1
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• pp.145-148
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• 2012

Spherical silica aerogel powders were fabricated via an emulsion polymerization method from a water glass. A water-in-oil emulsion, in which droplets of a silicic acid solution are emulsified with span 80 (surfactant) in n-hexane, was produced by a high power homogenizer. After gelation, the surface of the spherical silica hydrogels was modified using a TMCS (trimethylchlorosilane)/n-hexane solution followed by solvent exchange from water to n-hexane. Hydrophobic silica wet gel droplets were dried at 80 ℃ under ambient pressure. A perfect spherical silica aerogel powder between1 to 12 ㎛ in diameter was obtained and its size can be controlled by mixing speed. The tapping density, pore volume, and BET surface area of the silica aerogel powder were approximately 0.08 g·cm-3, 3.5 ㎤·g-1 and 742 ㎡·g-1, respectively.