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

• YAKHAK HOEJI
• /
• v.27 no.1
• /
• pp.29-36
• /
• 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
• /
• v.13 no.spc1
• /
• pp.145-148
• /
• 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.

• Applied Biological Chemistry
• /
• v.28 no.4
• /
• pp.226-232
• /
• 1985

Changes in lipid and fatty acid composition in Korean native Meju were investigated at one week interval over 6 weeks of fermentation. For the systematically, salicic acid column chromatography and gas liquid chromatography were used. Following results were obtained. 1. The lipid fraction obtained from the soared soybean and the cooked soybean were mainly composed of $72.47%{\sim}92.35%$ of neutral lipid, phospholipid and glycolipid were 4.64% and 4.88%, respectively. During fermentation period, lipid content decreased to 80.59%, but glycolipid and phospholipid contents increased. 2. The triglyceride contents of nonpolar lipids prepared from the cooked soybean and the soaked sobean was 89.66% and 87.83% respectively. Free fatty acid, diglyceride and sterol contents increased during fermentation, whereas triglyceride content decreased. 3. Lipids extracted from the soaked soybean and the cooked soybean were composed of 54.58% linoleic acid, $22{\sim}20%$ oleic acid, $10{\sim}12%$ palmitic acid and $3{\sim}5%$ stearic acid. 4. During the Korean native Meju fermentation in palmitic acid decreased from the second week and stearic acid through $3rd{\sim}4th$ week. Oleic acid and linoleic acid content decreased gradually, but linolenic acid content increased. 5. During the fermentation, myristic acid content of glycolipid fraction increased. Lipase activity reached to the maximum at the 3rd week.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.16 no.3
• /
• pp.75-84
• /
• 1987

Lipids in Bush Clover (Lespedza bicolor) seed were extracted with the mix ture of chloro-form-methanol (2 : 1, v/v) and then fractionated into neutral lipids, glycolipids and phospholipids by silicic acid column chromatography. Components and fatty acid composition of each fraction were determined by thin layer and gas chromatographies. The results were summarized as follows. In Bush Clover seed, the contents of neutral lipids, glycolipids and phospholipids were 71.75%, 23.26% and 4.99% respectively. Triglycerides(61.90%) and free fatty acids(22.04%) were the major components among the neutral lipids. Esterified sterols, free sterols, diglycerides and monoglycerides were the minor components. The major components of glycolipids were monogalactosyl diglycerides(38.19%) the others were esterified steryl glycosides, cerebrosides and digalactosyl diglycerides. The major components of the phospholipids were phosphatidyl cholines(36.46%), phosphatidyl inositols(21.52%) and phosphatidyl ethanolamines(17.29%). The major fatty acid of total lipid, neutral lipids and glycolipids were linoleic acid, linolenic acid, oleic acid and palmitic acid. On the other hand, predominate fatty acid of phospholipids were linoleic acid, palmitic acid, linolenic acid and stearic acid.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.13 no.4
• /
• pp.406-412
• /
• 1984

Total lipids (TL) from Korean pinenut (Pinuskoraiensis S & Z) were extracted, purified and fractionated into three lipid classes (neutral lipid: NL, glycolipid; GL, phospholipid; PL). Lipid contents(constituent components) and fatty acid composition of three lipid classes were determined by thin layer chromatography and gas chromatography. TL ranged from 69.0% to 69.8% in fresh pinenut and consisted of 95.9% to 96.7% NL, 3.2% to2.5% GL and 0.9% to 0.8% PL. In the NL, triglycerides were predominant (80.8%) with the smaller amounts of sterol, diglycerides, free fatty acids, sterol esters and hydrocarbons. Monogalactosyl diglycerides and esterified steryl glycosides (23.5%) were the major components of GL, but cerebrosides, steryl glycosides and digalactosyl diglycerides were also found as minor components. Of the PL, phosphatidyl choline (40.2%) and phosphatidyl ethanolamine (19.4%) were the major components, comprising over 60% of this class. Phosphatidyl inositol, lysophosphatidyl choline were also present in the PL. The major fatty acids in the NL were linoleic acid (48.6%), oleic acid (28.8%) and arachidic acid(14.4%), The fatty acid composition in the GL was similar to the pattern in the NL, but PL contained a higher percentage of palmitic acid (17.7%) and stearic acid (6.0%) than other lipid classes.

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

• Clean Technology
• /
• v.27 no.2
• /
• pp.115-123
• /
• 2021

This study demonstrates a new method for the synthesis of organic-inorganic hybrid particles composed of an inorganic silica shell and organic core particles. The organic core particles are prepared with a uniform size using droplet-based microfluidic technology. In the process of preparing the organic core particles, uniform droplets are generated by independently controlling the flow rates of the dispersed phase containing photocurable resins and the continuous phase. After the generation of droplets in a microfluidic device, the droplets are photo-polymerized as particles by ultraviolet irradiation at the ends of microfluidic channels. The core particle is coated with a nano complex composed of polyallylamine hydrochloride (PAH) and phosphate ion (Pi) through strong non-covalent interactions such as hydrogen bonding and electrostatic interaction under optimized pH conditions. The polyamine nano complex rapidly induces the condensation reaction of silicic acid through the arranged amine groups of the main chain of PAH. Therefore, this method enabled the preparation of organic-inorganic hybrid particles coated with inorganic silica nanoparticles on the organic core. Finally, we demonstrated the synthesis of organic-inorganic hybrid particles in a short time under ambient and environmentally friendly conditions, and this is applicable to the production of organic-inorganic hybrid particles having various sizes and shapes.

• Korean Chemical Engineering Research
• /
• v.60 no.3
• /
• pp.407-413
• /
• 2022

This study demonstrates a method for synthesis of amine functionalized and easily size controllable silica nanoparticles through biomimetic polyamine complex. First, we generate a polyamine nanocomplex composed of polyallylamine hydrochloride (PAH) and phosphate ion (pi) to synthesize silica nanoparticles. The size of polyamine nanocomplex is reversibly adjusted within the range of about 50 to 300 nm according to the pH conditions. Amine groups of the PAH in the nanocomplex catalyzes the condensation reaction of silicic acid. As a results, silica nanoparticles are synthesized based on nanocomplex in a very short time. Finally, we synthesize silica nanoparticles with various sizes according to the pH conditions. In the process of synthesizing silica nanoparticles, polyamine chains that act as catalysts are incorporated into the inside and surface of the particles, subsequently, amine groups are exposed on the surface of silica nanoparticles. As a results, the synthesis and surface modification of silica nanoparticles are performed simultaneously, and the silica nanoparticles introduced with amine groups can be easily synthesized by adjusting the sizes of the silica nanoparticles. Finally, we demonstrate the synthesis of functional silica nanoparticles in a short time under milder conditions than the conventional synthetic method. Furthermore, this method can be applicable to bioengineering and materials fields.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.14 no.3
• /
• pp.280-283
• /
• 1985

Lipid fractions of the roots of cultured (five years old) and wild (eight years old) Codonopsis lanceolata were analyzed. The most abundant fraction of the lipids extracted from cultured and wild roots of C. lanceolata was neutral lipid and the next came phospholipid and glycolipid in descending order. The percentage, however, of the neutral lipid in total lipid was comparatively low, while that of phospholipid, particularly high; 41.30% and 29.34% in that of cultured and wild one respectively. The richest fraction of neutral lipid was triglyceride; 39.49% and 32.88% in the cultured and the wild respectively, and followed by sterol esters and free acid. Noticed amounts of sterol esters and monoglycerides which is able to be used as an emulsifiers, were contained in the neutral lipid of roots; 27.74% and 5.11% respectively. The unsaturated fatty acid fraction of the total lipid hydrolyzate contained in cultured and wild C. lanceolata roots was 72.87% and 74.37% respectively. The main fatty acid contained in the total lipid hydrolyzate was linoleic acid, and followed by linolenic acid palmitic acid. The main saturated fatty acid was palmitic acid and lauric acid.