• Applied Biological Chemistry
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• v.35 no.1
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• pp.55-63
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• 1992

The essential oil of Korean ginger(Zingiber officinale Roscoe) was isolated by liquid carbon dioxide extraction method and fractionated into one hydrocarbon fraction and two oxygenated hydrocarbon fractions by using silica gel column chromatography. The compositions of the resulting oils were investigated by GC and GC-MS spectrometry. Out of 102 identified compounds, 44 were identified by comparing GC retention time and mass spectral data with authentic samples and 58 were tentatively identified according to mass spectral data only. The major compounds of hydrocarhon fraction were $zingiberene,\;{\beta}-sesquiphellandrene,\;{\gamma}-bisabolene,\;{\gamma}-cardinene,\;ar-curcumene$, and those of oxygenated hydrocarbon fractions wee geranal, sesquisabinene hydrate, borneol and zingiberenol. The major compounds of ginger oil were zingiberene, $citronellol+{\beta}-sesquiphellandrene,\;geranial,\;{\gamma}-bisabolene\;and\;ar-curcumene+geranyl\;acetate$, and ginger oil contained higher amounts of sesquiterpene hydrocarbons. The yield of extract was 6.96%.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.41-49
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• 2012

This study was aimed at the development of catalysts for the direct methanol synthesis by partial oxidation of methane. Mo-Bi-V-Al mixed oxide catalysts were prepared and characterized and used in the direct methanol synthesis reaction. The catalysts prepared by the sol-gel method had much larger surface areas than those prepared by the co-precipitation method. The larger the surface area was, the less the methanol selectivity was. The catalysts having larger surface area facilitate the complete oxidation of methane, decreasing the selectivity of methanol. The catalysts prepared by the sol-gel method showed higher methanol selectivity of 13% at $20^{\circ}C$ lower temperature than those prepared by the co-precipitation method. Through XRD analysis, it was revealed that the structures of the catalysts prepared by the two methods were different. In the reaction, methanol selectivity increased and carbon dioxide selectivity decreased with pressure due to the suppression of complete oxidation reaction at a high pressure.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.185-189
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• 2011

In this work, nano-sized M-ferrites (M=Co, Ni, Cu, Zn) for the decomposition of carbon dioxide were synthesized by the chemical co-precipitation. From the thermogravimetric analysis, it was clear that the maximum weight loss of each sample took place below $350^{\circ}C$. High temperature calcination resulted in more systematic crystallines, smaller specific surface area and larger particle size. An analysis by FTIR in the range of $375{\sim}406cm^{-1}$ revealed the presence of chelates at the octahedral site, which implies the formation of spinel structure in the ferrites. The current work showed that a $500^{\circ}C$ is the optimum heat treatment temperature of metal ferrites for $CO_2$ decomposition reaction.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.205-210
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• 2015

In this paper, microalgae lipid extractions were performed using conventional organic solvent and supercritical carbon dioxide (SC-$CO_2$) for biodiesel-convertible lipid fractions. The highest levels (58.31%) of fatty acid methyl ester (FAME) content in the lipid extracted by SC-$CO_2$ was obtained, and 18.0 wt.% crude lipid yield was achieved for Bligh-Dyer method. In the SC-$CO_2$ extraction, methanol as a co-solvent was applied to increase the polarity of extract. The experimental results indicated that crude lipid yield, FAME content and yield extracted by combination of SC-$CO_2$ with methanol were 12.5 wt.%, 56.32% and 7.04 wt.%, respectively, and this method could reduce the extraction time from 2 hour to 30 min when compared to SC-$CO_2$ extraction. Therefore, SC-$CO_2$ extraction is proven to be an environmentally-friendly and an effective method for lipid extraction from microalgae.

• Korean Journal of Materials Research
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• v.6 no.3
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• pp.324-332
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• 1996

DLC 박막을 RF 플라즈마 화학증착법(PECVD)을 이용하여 CH4와 CO2기체로부터 합성하였다. 증착압력, CH4와 CO2가스의 조성비, 바이어스 전압(-VB) 등의 증착조건 변화에 따른 증착속도는 증착층의 두께를 알파스텝으로 측정하여 결정하였으며, 박막의 구조 변화에 따른 증착속도는 증착층의 두께를 알파스텝으로 측정하여 결정하였으며, 박막의 구조 변화는 FTIR 분광분석을 이용하여 분석을 행하였다. 이 연구로부터 얻은 실험 결과는 다음과 같다: 1) 증착속도는 증착압력 및 바이어스 전압의 증가에 따라 증가한다. 2)바이어스 전압 300V이상에서, CO2량 증가는 순증착속도를 증가 시킨다. 3) 순수한 CH4가스를 사용할 경우에는 바이어스전압(-VB)이 증가함에 따라 박막내 수소의 함량과 sp3/sp2비는 감소하는 경향을 나타낸다. 4)증착압력이 증가함에 따라 박막내 수소함량은 증가하며, sp3/sp2비는 감소한다. 5)50mTorr의 증착압력에 증착시, CH4-+Co2 혼합가스에서 이산화탄소의 부피분율에 따라서는 박막내 수소함량은 감소하며, sp3/sp2비는 증가한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.273-279
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• 2003

버섯은 수확 후 이산화탄소 발생량이 2$0^{\circ}C$에서 200-500mg$CO_2$/kgㆍhr로 호흡속도가 아주 높은 편으로 저장이나 유통 중에 호흡속도를 낮추는 것이 버섯의 품질유지에 효과적이다. 따라서 저장고 또는 포장내의 기체조성을 변화시켜 신선 농산물의 호흡속도를 조절하여 저장하는 CA(Controlled Atmosphere)저장법이나, MAP(Modified Atmosphere Packaging)저장법을 버섯 저장에 이용하는 연구들이 보고되고 있으며 환경기체조성이 저장중인 버섯의 생리적인 현상에 미치는 영향에 관한 연구도 보고되고 있다. (중략)

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.29 no.9
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• pp.56-62
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• 2000

1997년 12월 일본 교토에서 개최된 COP3를 계기로 1999년 3월 에너지보존법이 대폭적으로 개정 및 강화되어졌다. 지구온난화의 주된 원인이 되는 이산화탄소는 에너지와 밀접한 관계를 가지고 있으므로, 에너지보존·자원보존의 추진은 지구온난화 대책의 추진과 동등한 의미를 가지고 있다고 하여도 과언이 아니다. 여기서는 건축설비계획의 관점에서 에너지보존법 개정의 요점과 그 대응책에 관해서 개요를 소개하였다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.33 no.6
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• pp.24-31
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• 2004

국내의 경우, 2004년 5월부터 시행예정인 다중이용시설 등의 실내공기질관리법에 따라서, 학교 등의 일부 건축물을 제외하고 신축공동주택 및 대부분의 거주용 공간에 대한 실내공기질관리법이 제정되었다. 이러한, 건축물 내에는 다양한 오염원(sources)과 휘발성유기화합물(VOCs), 포름알데히드(HCHO), 라돈(Radon), 석면(Asbestos), 일산화탄소(CO), 이산화탄소($CO_2$), 이산화질소(NO$_2$), 오존(O$_3$), 미세 먼지(PM10), 부유세균 등 유해오염물질(contaminants)이 존재하고 있다. 또한, 실내공기오염은 각 오염원에서의 유해오염물질 방산정도(emission rate)가 실내외 환경조건, 적용 건축자재의 종류 및 공법 , 환기설비의 특성 및 유형 등에 따라 큰 차이를 보이고 있으므로, 이에 대한 정확한 측정방법의 정립과 그에 따른 적절한 실태조사의 실시가 필요하다. (중략)

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.565-569
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• 2009

The interaction between polyvinylpyrrolidone(PVP) and silver cation has been studied in water at room temperature and atmospheric pressure. The PVP and PVP/Ag composite was observed by transmission electron microscopy (TEM), UV-VIS absorption spectroscopy, Raman spectroscopy and oxygen/carbon dioxide analyzer. We identified silver cations interacting with nonbonding electrons of the oxygen atom in the carbonyl group of PVP. It was shown that PVP/Ag formed stable composites.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.29-33
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• 2007

In order to protect the environment from the refrigerant pollution, the $CO_2$ may be regarded as one of the most attractive alternative refrigerants for an automotive air-conditioning system. Control methods for a $CO_2$ system should be different because of $CO_2$'s unique properties as a refrigerant. Especially, the high-side pressure of a $CO_2$ system should be controlled for the effective operation of the system. In this study, the high-side pressure setpoint algorithm was developed by using a neural network and a Lagrange interpolation method. These methods were compared. Simulation results showed that a Lagrange interpolation method was more effective than a neural network in the respect of its easiness of programming and shorter execution time.