• Bulletin of the Korean Chemical Society
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• 제24권4호
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• pp.527-530
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• 2003

• 한국자동차공학회논문집
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• 제6권1호
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• pp.108-121
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• 1998

Using gas chromatography, the light hydrocarbon emissions were analyzed from SI engine fueled with methane and liquified petroleum gas(LPG), and the effects of fuel and engine operating condition were discussed. For this purpose, 14 species of light hydrocarbon including 1, 3-butadiene were separated, calibrated with standard gas, and measured from undiluted emissions. The brake specific hydrocarbon emission(BSHC) and ozone forming potential(BSO)3 were calculated and discussed with the changes of fuel, engine speed, load, fuel/air equivalence ratio, coolant temperature, and spark timing. As a result, exhaust emission was composed of mainly fuel composed of mainly fuel comp- onent and other olefin components of similar carbon number. The olefin components such as ethylene and propylene determine most of the ozone forming potential. The fraction of fuel component in total hydrocarbon emission was bigger with methane fuel than with LPG fuel. Also fuel fraction increased at high speed or high speed or high temperature of exhaust gas, and to lesser extent with high coolant temperature and retarded spark. However, the effect of equivalence ratio had different tendency according to fuels.

• Applied Biological Chemistry
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• 제29권4호
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• pp.366-371
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• 1986

광도(光度)가 다른 포장조건에서 자란 6년근 인삼잎과 온도별 20시간 처리된 관행재배 6년근 절제엽중(切除葉中)의 지방산을 gas chromatography로 분석하였다. 재배광도(온도)가 높을수록 지방산 함량이 감소하였다. Linoleic, linolenic, palmitic과 palmitoleic acid가 다량(多量)지방산으로 80%였다. 지방산 조성의 유사도는 광도 20%까지는 차이가 크지 않았으나 30%에서 차이를 보여 20%가 재배 한계 광도인 것 같다. 재배광도가 높을수록 불포화 지방산비율이나 불포화대(不飽和帶)의 비율이 적어져서 고온에 대한 적응 기작으로 보였다. 30% 수광율과 수확기잎이 지방산특성이 유사하였으며 고온적응과 노화(老化)의 관계가 불분명(不分明)하였다. 단시간(短時間)의 고온처리 ($25^{\circ}$ 및 $35^{\circ}C$)는 지방산함량, 불포화산비율 및 불포화도의 비율을 증대시켰고 지방산 조성이 유사하여 장기 온도효과와는 반대의 결과였다.

• 한국기계가공학회지
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• 제19권10호
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• pp.1-7
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• 2020

In this study, a multichannel gas-liquid microextraction system is designed by integrating the automatic elution of extraction line and multichannel gas-purging liquid phase microextraction. The system uses an injection pump and inert gas to push the extraction solvent to a sample bottle of a gas-phase color autosampler and then implements multichannel gas-liquid microextraction and gas chromatography-mass spectrometry. The system also employs a three-way integrated micro-high-temperature heater, syringe pump, and microflow controller to realize the simultaneous processing of multiple groups of samples, thus improving the sample pretreatment speed and reproducibility and reducing human error. Autoinjection experiments were implemented with polycyclic aromatic hydrocarbon standard samples. The experiments show that the average recovery rate of the system exceeds 70%, and the relative standard among the channels is less than 15%.

• Journal of Mechanical Science and Technology
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• 제19권12호
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• pp.2197-2204
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• 2005

The combination of Gas chromatography (GC) for separation and Flame Ionization Detection (FID) for detection and identification of the components of a mixture of compounds is a fast and strongly proved method of analytic chemistry. The objective of this research was to design a combined High-speed miniature screening Gas chromatograph along with a Flame Ionization Detector for quick, quantitative and qualitative analysis of gas components. This combined GC-FID system is suitable to detect the volatile and semi-volatile hydrocarbons present in a gas mixture. The construction made it less expensive, easy to use and movable. The complete gas path was developed. On/off valves, temperature and flow sensors and their interface electronics were used for controlling purpose. A Microcontroller was programmed to measure the temperature and gas flow using the sensors and to control and regulate them using the electronics and valves. A pocket PC with its touch screen served as a user interface for the system. Software was developed for the pocket PC, which makes the communication possible with the Microcontroller. The system parameters can be indicated in the Pocket PC as simple text and also the analysis result can be displayed.

• 대한화학회지
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• 제7권2호
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• pp.122-127
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• 1963

Pyrolysis fo polyethylene and polypropylene has been studied in order to clarify the mechanism of chain scission and effect of oxygen on degradation. Rate of weight decrease was measured under nitrogen and air atmosphere at constant temperature for the samples of high density polyethylene, low density polyethylene and isotactic polypropylene, and then gaseous hydrocarbons produced from pyrolysis were analysed by gas chromatography. Although there is little substantial difference between composition of hydrocarbon gases from pyrolysis of high density polyethylene and low density polyethylene except some difference in quantity of total gas produced, gas composition from polypropylene pyrolysis differs from that of polyethylene pyrolysis. Gases from pyrolysis under air contain much more unsaturated hydrocarbons than those from pyrolysis under inert gas.

• 한국동물위생학회지
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• 제29권3호
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• pp.317-330
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• 2006

This study was conducted to develop the analytical method about simultaneous determination for synthetic antimicrobials in muscle by high performance liquid chromatography - mass selective detector (HPLC- MSD). Solid phase extraction (SPE), matrix solid phase dispersion (MSPD) and liquid-liquid extraction (LLE) have been adapted as pretreatment procedures for HPLC- MSD. Among various solvent tested, methanol was chosen for extraction of synthetic antimicrobials in muscles. For the optimized response, the values of various MS parameters including fragment voltage, drying gas flow, nebulizer pressure, drying gas temperature were verified. The average recovery rates using MSPD and SPE for muscles of bovine and pork were 78.9-127.1% and 78.3-121.7%, respectively. This method was verified the satisfactory performance for fourteen synthetic antimicrobials excepting carbadox in muscle of pork as detection limit of $0.05{\mu}g/g$ on API/ES SIM mode.

• 한국환경과학회지
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• 제11권4호
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• pp.375-382
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• 2002

The total hydrocarbon distribution of oil products obtained from the pyrolysis of four kinds of mixtures of polyethylene-polystyrene waste has been studied by multidimensional chromatography(high performance liquid chromatography followed by capillary gas chromatography)/mass spectrometry. Saturated, unsaturated and aromatic hydrocarbons in oil products were selectively pre-separated according to structural groups by HPLC and the weight fraction of each group was estimated by analysis of each component using GC-FID response factors. The hydrocarbon distribution of aliphatic fraction consists of $C_{5}$ to $C_{25}$ saturated and unsaturated hydrocarbons. And that of aromatics fraction consists of benzene, toluene, xylene, styrene, propenyl benzene, naphthalene, and some of derivatives. Pyrolysis temperature did not affect the ratio of total weight fraction of aliphatic over aromatic hydrocarbon distribution in case of PS only and PE-PS mixtures (1:1 and 1:4 wt. ratio) as a feed while affected the ratio of total wt. fraction in case of PE only. The optimal temperature for the maximum oil production was $600^{\circ}C$ for pyrolysis of PS and 1:1 and 1:4 mixtures of PE and PS. The optimal condition for aromatic recovery was $600^{\circ}C$ with 1:1 mixture of PE and PS. In this condition, aromatic was produced up to 90% of total oil product. The maximum yield of toluene, xylene, styrene, and propenyl benzene were 8.6, 8.9, 51.0 and 7.4% of feed for pyrolysis PS at $700^{\circ}C$, respectively. However, only 1.3% naphthalene was recovered at $700^{\circ}C$ with 1:1 PE:PS(by wt.).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.278-283
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• 2000

The activity of catalysts obtained by self-propagating high temperature synthesis in reaction of partial methane oxidation at atmospheric pressure was investigated. Basing on the compared results of X-ray analysis and gas chromatography analysis of reaction products, the dependence of compounds formation on the phase concentrations in the studied catalyst samples was found.

• 한국식생활문화학회지
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• 제21권3호
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• pp.319-324
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• 2006

묵은 배추김치의 휘발성 성분들을 고진공승화법을 이용하여 분리, 농축하였으며, GC-MS로 분석하였다. 총 62가지의 휘발성 성분들이 검출되었으며, 7개의 sulfur-containing compounds, 8개의 terpenes, 5개의 esters, 8개의 acids, 15개의 alcohols, 2개의 nitriles, 2개의 ketones, 11개의 aliphatic hydrocarbons, 4개의 miscellaneous compounds등으로 구성되어 있었다. 이 중 특히, acids인 acetic acid와 butanoic acid가 높은 함량을 나타내었다. 묵은 배추김치에서 향기활성성분을 규명하기 위해 고진공승화법을 이용하여 휘발성 성분들을 분리 및 농축 후 향 추출물 희석분석법으로 flavor dilution(FD) factor($Log_3FD$)를 구하였으며, GC-MS 및 GC-Olfactometry(GC-O)법으로 휘발성 성분들을 동정하였다. 이 결과 묵은 배추김치에서 총 16종의 화합물이 검출되었다. 이중 시큼한 냄새, 군덕내의 특성을 지닌 acetic acid, butanoic acid가 높은 FD factor를 보였으며, acids외에 높은 (FD > 9)를 나타내는 성분들로는 linalool, 2-vinyl-4H-1,3-dithin 등이 있었다.