• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.477-480
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• 2007

Hydrate phase equilibrium for the binary CO2+water and CH4+water mixtures in silica gel pore of nominal 6, 30, and 100 nm were measured and compared with the cacluated results based on van der Waals and Platteeuw model. At a specific temperature three-phase hydrate-water-vapor (HLV) equilibrium curves for pore hydrates were shifted to the higher-pressure condition depending on pore sizes when compared with those of bulk hydrates. Notably, hydrate phase equilibria for the case of 100 nominal urn pore size were nealy identical with those of bulk hydrates. The activities of water in porous silica gels were modified to account for capillary effect, and the calculation results were generally in good agreement with the experimental data.

• Nuclear Engineering and Technology
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• 제44권8호
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• pp.971-976
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• 2012

Silica-coated Au with Ag, Co, Cu, and Ir bimetallic radioisotope nanoparticles were synthesized by neutron irradiation, after coating $SiO_2$ onto the bimetallic particles by the sol-gel St$\ddot{o}$ber process. Bimetallic nanoparticles were synthesized by irradiating aqueous bimetallic ions at room temperature. Their shell and core diameters were recorded by TEM to be 100 - 112 nm and 20 - 50 nm, respectively. The bimetallic radioisotope nanoparticles' gamma spectra showed that they each contained two gamma-emitting nuclides. The nanoparticles could be used as radiotracers in petrochemical and refinery processes that involve temperatures that would decompose conventional organic radioactive labels.

• 한국산업보건학회지
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• 제26권1호
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• pp.20-29
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• 2016

Objectives: The purpose of this study is to simplify and standardize analytical method of polar solvents(methanol, isopropanol, n-butanol, acetone, methylene chloride and MIBK) in the working environmental by GC. Because NIOSH methods are various and complicated. Methods: The method is using the same stationary phase(5% phenyl 95% dimethylpolysiloxane), absorbent(silica gel) and desorption solvent(DMSO) for above 6 solvents. For the 6 solvents desorption efficiency, calibration curve, and limit of detection were studied Results: As the results, 6 solvents{2 groups ; first group(methanol/isopropanol/butanol) and second group(acetone/methylene chloride/MIBK)} could be separated and quantified within 10 minutes. Desorption efficiency from silica gell of 6 solvents using dimethylsulfoxide(DMSO) was methanol 86.2%, isopropanol 103.2%, n-butanol 101.8%, acetone 98.2%, methylene chloride 103.9% and MIBK 106.2% in the range of 0.2, 0.5, 2.0 times of TWA, consequently, satisfied NIOSH estimation level(beyond 75%). Correlation coefficient(r)in the range of 0.2~2.0 times of TWA, was above 0.999 for 6 solvent. LOD(mg/DMSO ml) using calibration curve in the range of 0.2~2 times of TWA was methanol 0.11, isopropyl alcohol 0.20, n-butanol 0.03, acetone 0.50, methylene chloride 0.05, MIBK 0.04 respectably. Conclusions: This method can be used at the sampling and analytical method for polar solvents by GC. Also, will be able to be applied with NIOSH methods.

• Journal of Applied Biological Chemistry
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• 제54권4호
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• pp.309-312
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• 2011

Chipped stem wood from Lindera glauca was extracted repeatedly with 80% aqueous methanol at room temperature, and the concentrated methanolic extract was successively partitioned with ethyl acetate (EtOAc), n-butyl alcohol, and $H_2O$. From the EtOAc fraction, four sterols were isolated through a repeated silica gel and octadecyl silica gel column chromatography. The chemical structures of the sterols were elucidated as ${\beta}$-sitosterol (1), 7-ketositosterol (2), 7${\beta}$-hydroxysitosterol (3), and daucosterol (4). Among them, compounds 2 and 3 were isolated for the first time from the stem woods of this plant.

• 한국식품과학회지
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• 제30권4호
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• pp.848-854
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• 1998

멸치어유로부터 EPA와 DHA가 농축된 분획을 제조할 목적으로, 흡착제, 보조용매, 추출압력을 달리하여 초임계 이산화탄소로 추출 분획한 후 추출수율과 지방산 조성을 측정하였다. 추출수율은 흡착제를 사용하지 않은 경우 추출시간의 증가에 따라 급격히 증가하여, 추출 3시간 후에는 63%였지만, 흡착제로 실리카겔과 질산은을 코팅한 실리카겔을 사용한 경우는 완만하게 증가하여 각각 26%와 33%였다. 어유를 질산은으로 코팅한 실리카겔과 혼합하여 추출하였을 때 추출잔류물 분획에 고도불포화지방산들이 농축되었다. 어유를 실리카겔과 혼합하여 초임계 이산화탄소에 보조용매로 hexane, ethyl acetate, ethanol과 함께 추출하였을 때 추출 2시간 후 추출수율은 각각 53.1, 86.3, 88.5%로 초임계 이산화탄소만으로 추출하였을때인 20.0%에 비하여 $2.7{\sim}4.4$배 증가하였다. 보조용매로 ethyl acetate를 사용하였을 때 추출잔류물 분획에서의 EPA와 DHA의 농도가 가장 높았다. 어유를 질산은이 코팅된 실리카겔과 혼합하여 초임계 이산화탄소에 보조용매로 ethyl acetate와 함께 추출하였을 때 추출 3시간 후 추출수율은 207, 276, 345 bar에서 각각 67.3, 76.4, 67.1%로 초임계 이산화탄소만을 사용하였을 때인 33.1%보다 2배 이상 증가하였다. 추출물 분획들의 지방산 조성은 원료 어유에 비하여 모든 추출압력 조건에서 $C14{\sim}C18$의 농도는 증가하였고, EPA와DHA 농도는 큰 폭으로 감소하였다. 추출압력 276 bar에서 추출잔류물 분획의 EPA와 DHA 농도는 각각 28.2%와 38.3%로 원료 어유에 비하여 각각 212%와 236% 농축되었다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.369-374
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• 2008

This study is an inorganic foaming ceramic by sol-gel reaction in order to overcome weak point of insulator using in construction equipment. We shall be able to confirm as the existing product substitute is possible result of this study. The solution where the silicate, the ceramic powder and the additive are included which makes foaming ceramic slurry, then the insulator made by used $CO_2$ Sol-Gel reaction. There being will be able to manufacture the insulator where the economical efficiency is excellent confirmed at the start product which is completed. The recording gel time decreases when the silicate will increase. Uses the hydrogen peroxide and fe make foam, when additionally surface preparation the fluorine resin, the water tolerance increases and will be able to complement the weak point of the silicate which omits in the water. The case which will use the loess powder with the research method which sees specially was environment-friendly product and according to appearing, the physical properties of nonflammability.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.118-119
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• 2016

γ-C₂S is known as a kind of substance that it does not react with water at room temperature. However it could react with the CO₂ producing CaCO₃ and silica gel as the carbonation products. Thus γ-C₂S can be used as a mineral addition to improve the compressive strength and durability of concrete. On the other hand, the manufacture of γ-C₂S can give an effective utilization of industrial by-product with low energy consumption and low CO₂ emission. This paper aims to summarize the development situation on this field.

• 대한화학회지
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• 제8권4호
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• pp.188-191
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• 1964

微量元素分析用 燃燒爐 內에서 內部酸化劑(酸化銀과 二酸化 망간의 混合物)와 함께 有機試料를 헤륨 氣流下에서 燃燒시키고 發生한 물은 칼슘카바이드管에 通하여 아세틸렌으로 變換시킨다. 二酸化炭素와 아세틸렌을 molecular sieve 5A 管에 室溫에서 吸着시킨 후 $340^{\circ}C$까지 溫度${\cdot}$프로그탬法으로 脫着시켜 실리카켈管을 通하여 分別流出시키고 熱傳導式 檢知器로 $CO_2$와 $C_2H_2$를 定量하는 方法을 發展시켰다. 벤조酸을 標準物質로 하여 作成한 檢量線을 使用하여 各種 有機試料中의 炭素 및 水素含量을 分析한 結果 平均誤差가 炭素의 경우 ${\pm}0.5%$, 水素인 경우${\pm}0.33%$ 이었다.

• Applied Biological Chemistry
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• 제49권1호
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• pp.82-85
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• 2006

산딸나무 열매를 100% MeOH로 추출하고, 얻어진 추출물을 EtOAc, n-BuOH 및 물로 용매 분획 하였다. 이 중 EtOAc 분획으로부터 silica gel과 octadecyl silica gel(ODS) column chromatography를 반복하여 3종의sterol 화합물을 분리, 정제하였다. 각 화합물의 화학구조는 NMR, MS 및 IR 등의 스펙트럼 데이터를 해석하여, ${\beta}-sitosterol$(1), $stigmast-4-en-6{\beta}-ol-3-one$(2), daucosterol(3)으로 동정하였다. 이 화합물들은 산딸나무에서 처음 분리되었다.

• Journal of Applied Biological Chemistry
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• 제55권4호
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• pp.217-220
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• 2012

오가피(Acanthopanax sessiliflorus Seeman) 열매를 실온에서 70% ethanol (EtOH)로 추출하고 이 추출물을 ethyl acetate (EtOAc) 분획, n-butyl alcohol 분획, $H_2O$ 분획으로 나누었다. EtOAc 분획에 대하여 silica gel, octadecyl silica gel 및 Sephadex LH-20 column chromatography를 반복 실시하여 2종의 화합물을 분리, 정제하였다. NMR, infrared spectroscopy, 및 electron ionization/mass spectrometry 등의 spectrum을 해석하여, 화합물 1과 화합물 2를 각각 3,5-dihydroxycinnamic acid과 protocatechuic acid 로 구조를 결정하였다. 화합물 1은 오가자에서는 처음으로 분리된 화합물이다. 또한 이 화합물에 대한 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)diammonium salt, 1,1-diphenyl-2-picrylhydrazyl 및 oxygen radical absorbance capacity radical 소거능을 이용한 항산화 활성을 측정하였는데, 모두 vitamin C보다 2배 이상 활성이 높은 것으로 나타났다.