• Carbon letters
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• 제3권4호
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• pp.187-191
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• 2002

In the present research, we prepared the activated carbon (AC) sorbents to remove gas-phase mercury. The mercury adsorption of virgin AC, chemically treated AC and fly ash was performed. Sulfur impregnated and sulfuric acid impregnated ACs were used as the chemically treated ACs. A simulated flue gas was made of SOx, NOx and mercury vapor in nitrogen balance. A reduced mercury adsorption capacity was obtained with the simulated gas as compared with that containing only mercury vapor in nitrogen. With the simulated gas, the sulfuric acid treated AC showed the highest performance, but it might have the problem of corrosion due to the emission of sulfuric acid. It was also found that the high sulfur impregnated AC also released a portion of sulfur at $140^{\circ}C$. Thus, it was concluded that the low sulfur impregnated AC was suitable for the treatment of flue gas in terms of stability and efficiency.

• 약학회지
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• 제39권3호
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• pp.283-288
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• 1995

Rapid gas chromatographic profiling method was applied to saliva from healthy subjects for the analysis of free organic acids. Saliva samples were first saturated with NaHCO$_{3}$ and extracted with diethyl ether. The aqueous phase was solid-phase extracted using Chromosorb P as the adsorbent and diethyl ether as the eluent after the acidification and NaCl saturation, followed by triethylamine treatment. The resulting tiiethylammonium salts of acids were directly converted into stable tert.-butyl-dimethylsflyl derivatives, with subsequent analysis by dual-capiuary column gas chromatography and gas chromatograpy -mass spectrometry. From the ten saliva samples studied, twenty eight free organic acids including various fatty acids, hydroxy acids, dicarboxylic acids, md aromatic acids were tentatively identified. Among the acids identified , the concentration of lactic acid was highest for five saliva samples while $\alpha$-hydroxyisocaproic acid was most abundant for me sample, and succinic acid and glycolic acid for two samples. respectively. When the GC profiles were simplified to the corresponding acid retention index spectra of bar graphical form, they presented characteristic patterns for each individual.

• 한국식품과학회지
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• 제4권3호
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• pp.213-223
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• 1972

This paper chose the methods of methylesterification of the use of methoxide, the mixture solution of methanol-benzen-sulfuric acid in transesterification of the fat in cow's milk and modified powder milk and separated by gas liquid chromatography with F.F.A.P., D.E.G.A. as liquid phase. Quantitative analysis of the fatty acid of milk fat in cow's milk and modified powder milk was determined by gas liquid chromatography using the method of temperature programming which should be used to obtain satisfactory separation of short chain fatty acid on the chromatogram. It was found that the fatty acid composition of cow's milk and modified powder milk are all the major fatty acid of milk fat obtained by GLC analysis. Main components was found to be from butyric acid to arachidonic acid showing Fig. 3, 4, 5 and Table 4, 5, 6, 7, 8, 9.

• Journal of Acupuncture Research
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• 제28권2호
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• pp.89-95
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• 2011

Objectives : The purpose of this study was to investigate the composition of Rehmannia glutinosa's essential oils with Rehmanniae Radix herbal acupuncture Methods : I obtained the essential oils of Rehmannia Radix by hydrodistillation extraction method and supercritical fluid extraction(SFE) method, and then I analyzed those by GC/MS(gas chromatography/mass spectrum). Results : 1. With GC(gas chromatography) and GC/MS(gas chromatography/mass spectrum) analysis. I identified 9 compounds in the Rehmanniae Radix's essential oil obtained through the SFE method. The main compounds were as follows : Hexachloroethane(2.24%), N-Butyl-benzenesulfonamide(2.05%), hexadecanoic acid(1.93%), hexadecanoic acid, ethyl ester(3.49%), 9,12-Octadecadienoic acid(z,z)(2.70%), (9E)-9-Octadecenoic acid(6.14%), ethyl linoleate(4.43%), ethyl oleate(5.80%). 2. I failed to get Rehmanniae Radix's essential oil obtained through the hydrodistillation method. 3. With GC(gas chromatography) and GC/MS(gas chromatography/mass spectrum) analysis. I identified 4 compounds in the Rehmanniae Radix's essential oil obtained through the hydrodistillation method. The main compounds were as follows : Ethylbis(trimethylsilyl)amine(1.04%), 2-(Trimethylsiloxy)benzoic methyl ester(2.65%), Hexadecanoic acid trimethylsilyl ester(12.61%), octadecanoic acid, trimethylsilyl ester(6.28%). Conclusions : The substances by hydrodistillation method may not perfectly match with the substances by supercritical fluid extraction(SFE) method in essential oils extracted form Rehmanniae Radix. But, the main substances was assumed Hexadecanoic acid and octadecanoic acid.

• 한국식품영양과학회지
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• 제6권1호
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• pp.49-53
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• 1977

시판(市販) 고가(高價)의 기름에 저렴(低廉)한 기름을 혼입(混入)시키는 일이 흔히 일어나므로 이것을 쉽게 검색(檢索)하기 위한 방편(方便)으로 각 식용유(食用油)의 지방산조성(脂肪酸組成)을 gas chromatography 법(法)에 의해서 조성비(組成比)를 조사(調査)하였으며 이들 지방산(脂肪酸)의 조성(組成)을 보면 참기름은 myristic, palmitic, stearic, linoleic acid와 미량(微量)의 linolenic acid로, 미강유(米糠油)와 대두유(大豆油)는 myristic, palmitic, stearic, oleic, linoleic 및 linoleic acid, 들기름은 palmitic, stearic, oleic, linoleic, linolenic acid, 해바라기 기름은 palmitic, stearic, oleic acid 및 linoleic acid로 이루어져 있다. 이상의 결과로 볼 때 참기름에도 linolenic acid가 극미량(極微量) 밖에 존재하지 않으므로 이것이 풍부한 타(他)의 기름이 혼입(混入)되었을 경우 쉽게 검출(檢出)할 수 있을 것이다.

• 한국환경과학회지
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• 제5권5호
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• pp.555-560
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• 1996

미생물 세포벽의 독성 물질 (내독소)을 incubator, centrifuge와 UV-Vis spectrophotometer를 이용하여 추출한 후 지방산 조성을 Gas Chromatography로 분석하였으며 독성 물질의 치사 독성과 발열 활성을 측정, 그 결과를 서로 비교하였다. 지방산 조성 분석 결과 V. vulnificus의 독성 물질 (내독소)에 대해 tetradecanoic acid가, E. coli게 대 해서는 dodecanoic acid, 그리고 S. typhimurium에 대해서는 decanoic acid가 주 지방산이었으며 이들 세 지방산이 세가지 독성 물질에서 대부분을 차지하였다 (70% 이상). 지방산 조성에서 특이한 점은 tetra-decanoic acid가 V. vulnificus에 대해 주 지방산이라는 점과 세가지 독성 물질 모두 hexadecanoic acid의 양이 매우 적다는 것이다 (2% 이하). V. vulnificus의 독성 물질의 mice 에서의 치사 독성 (LD50이 52.5 mg/kg)은 E. soli(56.5mg/kg)와 비슷하였으나 S. typhimunum (37.5mg/kg) 보다는 약하였으며 V. vulnificus의 독성 물질의 rabbit에서의 발열 활성은 E. coli보다 강하였으나 5S typhimurium 보다는 약하였다.

• 한국식품과학회지
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• 제4권1호
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• pp.24-28
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• 1972

Synthetic food preservatives were analysed in foods collected in Seoul area on Aug. 10, 1971. Sorbic acid, benzoic acid, dehydroacetic acid and butyl p-hydroxybenzoate were determined by the simultaneous gas chromatography using FID at $200{\circ}C$ and a column of Chromosorb W coated with 5% $DGS{\sim}1%\;H_3PO_4$. The recovery rates of each preservative were from 76.7% to 96.3%. The calibration curves show linearity within a range from 0.3 to $2.5{\mu}g$ of standard preservatives. The results obtained were as follows: 1) Benzoic acid was used as well as butyl p-hydroxybenzoate in soy. 2) Sorbic acid was not found in soy. 3) From all breads and biscuits benzoic acid was found as trace. 4) Detected preservatives were below the range of permitted limit. 5) From 2 soy among 15 samples dehydroacetic acid was found.

• 환경위생공학
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• 제4권2호
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• pp.91-99
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• 1989

An anaerobic acidogenic fermentation experiment was carried out in order to investigate the distribution of volatile acid products and gas generations with varing temperatures and pH values. The experiment was carried out using $1\%$ glucose as substrate and a pair of 3.5 liter vessle as bench scale batch reactors. The reactors were operated for 7 days at 25, 30 and $35^{\circ}C$ and at pH values of 4.0, 4.5, 5.0, 5.5 and 6.0 at each temperature conditions. Major products at all experiment pH's at $35^{\circ}C$ were acetic acids and butyric acids which together composed around $90^{\circ}F$ of total product acids. At higher pH values at $35^{\circ}C$, propionic acid reached around $10\%$. At all experiment conditions, 52 to $55\%$ of generated gases comprised of hydrogen gas and 45 to $48\%$ of carbon dioxide. With temperature increase from 25 to $35^{\circ}C$, the production rate of acetic acid increased 2.9 fold, butyric acid 22 fold, hydrogen gas 2.0 fold and carbon dioxide gas 2.3 fold. Optimum reaction conditions for highest production of acetic acid and hydrogen gas was determined to be pH 5.5 at $35^{\circ}C$.

• 공업화학
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• 제33권2호
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• pp.229-233
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• 2022

In this study, a gas-liquid hybrid atmospheric pressure plasma reactor of the dielectric barrier discharge method was fabricated and characterized. The solubility of copper oxide in the organic acid solution was increased when argon having a larger atomic weight than helium was used during plasma discharge. There was no significant effect of mixing organic acid solutions under plasma discharge treatment on the variation of copper oxide's solubility. As the applied voltage for plasma discharge and the concentration of the organic acid solution increased, the dissolution and removal power of the copper oxide layer increased. Solubility of copper oxide was more affected by the concentration in organic acid solution rather than the variation of plasma applied voltage. The usefulness of hybrid plasma reactor for the surface cleaning process was confirmed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.317-319
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• 2000

We fabricated the QCM with Langmuir-Blodgett(LB) film deposited at the different subphase pH and investigated the resonant frequency response by the injection of organic gas response. In the $\pi$-A isotherms, the monolayer on the air/water interface had different limiting area per molecule and showed more condensed status as increasing the subphase pH. When palmitic acid LB film was deposited on the QCM, the resonant frequency shift was proportional to the deposited layer and had more resonant frequency shift in the case of the higher pH range as expected. In the resonant frequency for the injection of organic gas, it has been improved in the case of LB film fabricated at the lower subphase pH range and dependant upon the molecular weight of organic gas.