• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2910-2915
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• 2008

This paper was investigated the behaviors of the engine and combustion phenomena for various LPG compositions in the semi-return type system, which is not recircurated to LPG tank through furl rail, applied LPi engine during a cold idle condition and including a cold start of the engine. Cyclic HC and NOx emissions were measured at exhaust port to examine their formation mechanical and reduction mechanical with fast response gas analyzers. Various ignition timing is experimented to study the characteristics of combustion phenomena, HC/NOx emissions during fast idle. Also, this study was investigated start delay time, cylinder pressure, HC/NOx emissions, Mass Fraction Burned, starting time to evaluate performance of transient cold startability. Compared to the return type system, the semi-return type system have advantages in point of production cost and equivalent performance of engine starting time and pressure settling time.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3317-3322
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• 2007

THC(Total Hydrocarbon) emissions during cold start and warm-up phase constitute the majority of THC emissions during the FTP-75 mode. As the basic approach to improve the emission performance of Gasoline engine during transient phase, the effect of spark timing retard from MBT on THC emission characteristics is studied by engine test using a Fast response Flame Ionization Detector(FFID). A cyclic analysis of the combustion process shows that high THC emissions are produced first few cycles during the transient phase. This paper presents the results of engine performance and emission of Gasoline engine with various spark timing. consequently, This paper was focused on the combustion phenomena with various spark timing during transient phase which was analyzed by Fast response Flame Ionization Detector (FFID) equipment to measure the cyclic THC emission characteristics.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.12
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• pp.907-914
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• 2008

This study is mainly focused on the assessment of return, semi return, and returnless fuel supply system for an LPi engine. In order to compare the return type with returnless one with various LPG blends, combustion analysis and cyclic THC emission characteristic were tested at the part load operating condition of the LPi engine. Considering heat balance of each fuel supply systems, pressure and temperature increment of return type showed lower at the fuel rail during idle warm up operation. However, those of returnless type at LPG tank maintained stable and slow increment because the heat transfer from the LPi engine was minimized. Finally, hot restartability of each fuel supply systems were evaluated with the various LPG blends and fuel temperatures. As a result, semi return type has equivalent performance to return type considering combustion and emission characteristic, hot restartability performance for LPi engine.

• Analytical Science and Technology
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• v.31 no.1
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• pp.23-30
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• 2018

Twenty-two allergy-induced aromatics in children were analyzed using a gas chromatography flame ionization detector (GC-FID) and gas chromatography mass spectrometer (GC-MSD). Analytes were extracted using an automatic Soxhlet extractor and centrifuged for 10 min in a fast freezing centrifuge, and the supernatant was transferred into a 2 mL vial and injected in split mode. Under the established conditions, the calibration curve showed linearity with a correlation coefficient of 0.996 or more. A wide range of sensitivity of 6.7 to 1,859,839 depending on the device characteristics and detector used was shown. The detection limit of the device was 0.0032 to $0.0335{\mu}g/mL$, and the maximum detection limit was less than $0.1{\mu}g/mL$. The detection limit of the method ranged from 0.0033 to $0.1161{\mu}g/mL$. In addition, the limit of quantification ranged from 0.0100 to $0.5422{\mu}g/mL$, with a level of precision ranging from 0.21 % to 4.89 % and a degree of accuracy ranging from 89 % to 111 %. The analytical method developed in this study was applied to commercial products.