• Archives of Metallurgy and Materials
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• v.66 no.3
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• pp.771-776
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• 2021

Iron oxide nanoparticles were incorporated to form composite microspheres of SiO₂ and Fe₂O₃ for magnetic separation of the particles after adsorption or photochemical decomposition. Economic material, sodium silicate, was purified by ion exchange to prepare aqueous silicic acid solution, followed by mixing with iron oxide nanoparticles. Resulting aqueous dispersion was emulsified, and composite microspheres of SiO₂ and Fe₂O₃ was formed from the emulsion droplets as micro-reactors during heating. Removal of methylene blue using the composite microspheres was performed by batch adsorption process. Synthesis of composite microspheres of silica containing Fe₂O₃ and TiO₂ nanoparticles was also possible, the particles could be separated using magnets efficiently after removal of organic dye.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.151-157
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• 2000

This study was carried out to isolate and identify the maysin and related flavonoid analogues in corn silks. Silks were covered with silk bag to prevent pollination and were sampled at 3-5 days after silking. The silks were filled with 100% MeOH and stored at $0^{\circ}C$ until analysis. The MeOH extracts of corn silks were filtered and concentrated at 35-4$0^{\circ}C$. The ${CH}_2$${Cl}_2$ was added on the concentrated aqueous solution to remove the chlorophyll and lipids. The Cis open column (25mm$\times$54 cm) was washed and activated with serial treatment of 500$m\ell$ of 100% MeOH(twice)longrightarrow75% MeOH longrightarrow50% MeOHlongrightarrow30% MeOHlongrightarrow100% $H_2$O(2 times). The concentrated aqueous solution was applied to the $C_{18}$ column and washed with $H_2O$ several times to remove the sugars and water soluble pigments. Neochlorogenic acid, chlorogenic acid and 4-caffeoylquinic acid were eluted with 10% MeOH, and rhamosyl isoorientin was eluted with 30% MeOH, but maysin was eluted with 50% MeOH from the $C_18$ open column. Collected fractions were analyzed with HPLC by using revers-phase Ultras-phere $C_{18}$ column (4.6$\times$250mm, 5$\mu\textrm{m}$) and $H_2$O (10% MeOH containing 0.1% $H_3$${PO}_4$)/MeOH (100% MeOH containing 0.1% H$_3$PO$_4$) linear gradient from 20% to 90% MeOH for 35 minutes, a flow rate of 1 $m\ell$/min and detection at 340nm. The selected fractions were concentrated and applied to the silicic acid column. Maysin was eluted with 500$m\ell$ of 100% ethyl acetate from the silicic acid column for the first purification, and the purity of collected fractions was about 75%, but the purity from the second purification with the Cis column (1/2 $\times$ 43") was greater than 95%. FAB-MS spectral data was obtained with VG7O-VSEQ VG analytical fast atom bombardment mass (UK). $^1$H-NMR and $^{13}$ C-NMR data were obtained with Bruker DPX 400 MHz NMR spectrometers (German) in DMSO-d$_{6}$ at 400 and 100 MHz, respectively.vely.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.169-176
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• 1988

Lipid contents, fatty acid compositions and free sugar contents of dried ginsengs grown for different years were studied. The lipid and free sugar were separated and quantified by silicic acid column chromatography, thin layer chromatography, gas liquid chromatography and high performance liquid chromatography. Ginseng contained $1.07{\sim}67%$ crude lipid and the hightest lipid content was shown in 3 year old root. The lipid fractions obtained by silicic acid column chromatography were mainly composed of neutral lipid$(51.35{\sim}72.30%)$. The contents of phospholipid and glycolipid in total lipids were $15.03{\sim}34.59%$ and $11.83{\sim}20.72%$, respectively. As the ginseng grew, neutral lipid content increased gradually but glycolipid decreased to the half of the one year old root. Seven components of neutral lipid separated by thin layer chromatography were identified but the other two components were not able to be identified. Triglyceride content was $14.42{\sim}23.91%$, sterol ester and unidentified material(II) were $13.58{\sim}21.26%$ and $7.13{\sim}15.83%$ respectively. The major fatty acids were linoleic acid, palmitic acid, oleic acid and linolenic acid. Linoleic acid content of total and neutral lipid was $61{\sim}65%$ palmitic acid content in phospholipid was $26{\sim}39%$ and one year old root showed the hightest contents. The fatty acid composition of neutral lipid was similar to the pattern of total lipid. Linolenic acid content of glycolipid decreased gradually. Free sugars were composed of rhamnose, fructose, glucose, sucrose, maltose and an unidentified material. The content of sucrose was $92{\sim}94%$ of total free sugars. Two year old root showed the highest sugar content and it decreased since then.

• Economic and Environmental Geology
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• v.28 no.6
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• pp.571-577
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• 1995

Several acid-sulfate clay deposits associated with silicic magmas occur in the Haenam area of the southwestern part of Korea. Geology of the studied area consists of tuffs, granitic rocks, quartz porphyry, rhyolite, andesite and sedimentary rocks. The granitic rocks and quartz porphyry intruded tuffs and sedimentary rocks. The rhyolite and tuffs around the mines have undergone hydrothermally weak or strong alteration. Gold contents with major and trace elements have been determined for a total of sixty-seven specimens of fresh igneous rocks, wall rocks and minerals such as dickite and alunite by graphite furnace atomic absorption spectrometer and inductively coupled plasma. Gold is enriched in the alunite vein and the silicified zone, but is depleted in dickites and hydrothermally altered rocks with dickite of the Seongsan deposit. Gold is especially concentrated near the faults or conjunction area of two faults. High content of gold is shown in the mineral assemblages of alunitequartz- pyrite in the alunite vein and silicic zone of the Seongsan deposit compared with that of minerals and rocks from another deposits distributed in the studied area. Gold content in tuffs and dickites with pyrite is generally low. Gold content in silicified tuff tends to show positive correlations with content of As, Hg and Sb. Variation trends of Cd, Hg and Sb are similar to those of gold content. From the result of gold content variations, gold may be transported and concentrated by mineralizing solutions ascending along the cracks like fault. Therefore, it is important to survey alunite vein and silicified zone at the conjunction of faults, and to analyze pathfinder elements such as As, Hg and Sb for geological and geochemical exploration of gold in the studied deposits.

• Journal of Conservation Science
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• v.18 s.18
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• pp.89-96
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• 2006

Surface layers of stone cultural properties including the soluble salt need consolidation because they are mostly very weak. There is a lot of research on the penetration depth of consolidant in stone and the effect of consolidant on mechanical stability of deteriorated structure. But some conservation experiences show that consolidation with silicic acid ester is not successful on salt contaminated stone cultural properties. In this study, in order to assess the influence of soluble salts$(CaSO_4\;2H_2O,\;NaNO_3)$ on the efficiency of consolidation on the deteriorated stone cultural properties(Nationalgalerie, Berlin, Germany) sandstone samples have been soaked with the salts solution. The impregnation of consolidant based on ethyl filicate have been afterwards carried out on these samples. As a result, it confirms that the soluble salts act as a preventer or consolidation. They fill up the pores in the stone and prevent that sufficient amount of consolidant enter deeply into the stone. According to this result, if use silicic ethyl ester as a consolidant for the research object which is built by Nebra sandstone, desalination is necessary before the treatment with consolidant. But it is also reported by other researches that some soluble salts improve the consolidation effect. Therefore it should be necessary to pre-study about salt and its harmfulness before the consolidation treatment. In order to consolidate without the aggravative damage in salt contaminated stone cultural heritage, we must first of all study the relations among salt, stone and consolidant.

• Analytical Science and Technology
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• v.23 no.4
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• pp.423-428
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• 2010

In this study, VOCs of black gel pen inks was screening to identify individual characteristic of gel pen inks. Detected VOCs was total 20 species(isopropylalcohol, 2-methyl-2-propanol, 2-butanone, hydrazinecarbothioamide, benzeneacetic acid (ethyl ester), benzeneacetic acid, dimethoxymethy-silane, 2,2-dimethoxybutane, tetrahydro-2-methyl-furan, 1,2-ethanediol, silicic acid (tetramethyl ester), 1,2-propanediol, propyleneglycol, 3-ethyl-3-hexanol, 1,1-dipropoxy-propane, 2-butoxy-ethanol, 2,2'-oxybisethanol, 1-butyl-benzene, 2-pyrrolidinone, 2-(2-butoxyethoxy)-ethanol). We detected 2,2-dimethoxybutane (3.02~47% ratio) and tetrahydro-2-methyl-furan (1.19~52.19% ratio), 1,2-ethanediol (52.83~95.84% ratio). In case of manufacturer, manufactured ink was able to discriminate between Japan and Korea by distinct characteristics (Japan: 1,2-ethanediol, 52.83~95.84%, Korea: 1,2-propanediol, 76.17~93.51%). The results of this study indicated that distinct characteristic about manufacturers and brands could make a classifring tool of inks for identification of between gel pen inks.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.214-222
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• 1996

This study was carried out to obtain the basic data on artificial culture of Phellinus linteus. The optimum condition for the mycelial growth was $25{\sim}30^{\circ}C$ and pH $6.0{\sim}7.0$. The carbon sources such as D-glucose, D-mannose and Dextrose were favorable to mycelial growth. As nitrogen sources, peptone, cassamino acid and glutamic acid appeared to be favorable. The optimum C/N ratio was about 20:1, when 2% of glucose was provided as a carbon source. The better organic acids and vitamin among tested ones were gallic, silicic acids and biotin. The mineral nutrients of $KH_2PO_4,\;FeSO_4{\cdot}7H_2O,\; MgSO_4{\cdot}7H_2O,\;ZnSO_4{\cdot}7H_2O$ were effective and the optimum concentrations were 0.05, 0.001, 0.02 and 0.003%, respectively.

• Korean Journal of Food Science and Technology
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• v.7 no.2
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• pp.74-81
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• 1975

Nonvolatile organic acids were determined in raw Chinese cabbage, Kimchis fermented at $6^{\circ}{\sim}7^{\circ}C$ and at $22^{\circ}{\sim}23^{\circ}C$. Total acids were isolated by ion-exchange chromatography and quantitative determination of individual acids was performed by silicic acid partition column chromatography. Acids were identified qualitatively by paper chromatography. Palatability of Kimchis was evaluated by nine pannels. Results were as follows: Maleic, fumaric, lactic, succinic, malonic, oxalic, glycolic, malic, citric, tartaric, sulphuric and phosphoric acid were found in raw Chinese cabbage. Kimchis fermented at $6^{\circ}{\sim}7^{\circ}C$, and at $22^{\circ}{\sim}23^{\circ}C$. In raw Chinese cabbage, most of organic acids were in salt form and malic acid was highest in amount. In Kimchi fermented at $6^{\circ}{\sim}7^{\circ}C$, the amount of lactic acid and succinic acid was higher than that in Kimchi fermented at $22^{\circ}{\sim}23^{\circ}C$, and, tartaric, oxalic, malic, malonic, maleic, glycolic and fumaric acids were less than those in Kimchi fermented at $22^{\circ}{\sim}23^{\circ}C$. Kimchi fermented at $6^{\circ}{\sim}7^{\circ}C$ had a more flavorous sour taste than Kimchi fermented at $22^{\circ}{\sim}23^{\circ}C$. It is assumed that large amount of lactic acid and succinic acid in Kimchi fermented st $6^{\circ}{\sim}7^{\circ}C$ have a connection with flavorous sour taste.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.1
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• pp.15-21
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• 1986

This study was conducted to research the industrial utilizaion of the maize germs separated in the manufacture of the cornstarch. The maize germs contained crude protein (25.3%) and crude fat (19.2%), with the 512 Kcal/100g of determined food energy values. It was found to have the valuable amounts of essential minerals, such as the content of calcium and phosphorus were low (53.0, 12.3mg%), while those of potassium (495.4mg%), magnesium (95.0mg%), zinc (48.3ppm) and manganese (45.2ppm) were plentiful. It was noted that the iodine value was 44.0, saponification value 292.3, acid value 1.5 and peroxide value about 3.3. The lipid fractions obtained by silicic acid column chromatography were mainly composed of neutral lipid, whereas, the contents of glycolipid and phospholipid were scarcely. The major fatty acids in total lipids were linoleic $(60{\sim}62.5%)$, oleic $(20{\sim}22.5%)$ and palmitic $(10{\sim}13.5%)$ acids. The content of the unsaturated fatty acids was more predominant than that of the saturated fatty acids. The content of the insoluble proteinous nitrogen (32.5%) was the most abundant. whereas, the contents of soluble proteinous nitrogen (12.7%) and peptide proteinous nitrogen (3.3%) were low. The major amino acids of the maized germs were glutamic, glycine, alanine and aspartic. It has been identified by the SDS-disc electrophoresis that the protein of maized germs had $5{\sim}6$ bands. Compared with standard substances, the molecular weight of the main protein was estimated to be $14,500{\sim}24,500$.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.23-28
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• 1987

The effects of phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI), phosphatidic acid (PA), phosphatidyl glycerol (PG), and cardiolipin (CL) on the flavor stability of purified soybean oil were studied. Purified soybean oil obtained from soybean oil by silicic acid chromatography does not contain measurable iron, tocopherols and phospholipids. Three hundred ppm of PC, PE, PI, PA, PG, or CL was added to the purified soybean oil, with and without 1ppm ferrous iron added. The flavor stability of sample, which was stored at $60^{\circ}C$ for 10 days in dark oven, was determined by a combination of volatile compounds formation and molecular oxygen disappearence in the headspace of air-tightly sealed serum bottle every 48 hrs. Results showed that, in general, phospholipids worked as prooxidant in the pufified soybean oil without ferrous iron added, and worked as antioxidant in the oil, when added 1ppm ferrous iron. The results also suggest that phospholipids work as prooxidant by increasing the solubility of oxygen on the surface of oil, and work as antioxidant in the oil containing 1 ppm ferrous iron by chelating iron. The results showed that PE and PA are better antioxidants than PC and PG. CL and PI showed the lest antioxidant activities in the oil will 1ppm ferrous iron added.