• 한국자동차공학회논문집
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• 제11권1호
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• pp.64-71
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• 2003

In order to analyze the effect of the chemical structure and the cetane number of reformed diesel fuels by ultrasonic energy irradiation, proton nuclear magnetic resonance spectrometer$(^1H-NMR)$ was used. From the study, following conclusive remarks can be made. 1) Branch Index(BI), aromatics percentages, and alpha methyl radical$(H_{\alpha})$ of the reformed diesel fuels by ultrasonic energy irradiation decreased more than the conventional ones. 2) All the cetane numbers which were calculated from carbon type structure and hydrogen type distribution of the reformed diesel fuels increased more than the conventional ones. 3) It is more reasonable to predict cetane number equation from carbon type structure than from hydrogen type distribution. 4) BI, aromatics percentages, and $H_{\alpha}$ on both for conventional fuel and reformed diesel fuels by ultrasonic energy irradiation are inversely proportional to cetane number fur these fuels.

• 한국대기환경학회지
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• 제8권4호
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• pp.229-239
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• 1992

A receptor model application was performed by using a chemical mass balance (CMB) model to identify and apportion the specific source of airborne organic pollutants, particularly polynuclear aromatic hydrocarbons (PAHs). Source profiles of PAHs produced from the combustion of fossil fuels for CMB modeling were prepared by measuring them in emission gases. The emission sources which were examineed for the development of PAH source profiles are a coal-fired furnace using Yontan, a bunker-C iol heating boiler, and gasoline-and diesel engine automobiles. The ambient concentrations of PAHs were determined at four sites in Daejon city in 1991 with a seasonal variation. Wintertime air samples contained more extractable organic matter than summertime samples. The results of CMB modeling were various depending on the sampling sites and seasons, but the emission from bunker-C oil heating boliers was the predominant factor to affect local air quality throughout the year.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.181-184
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• 2003

메인모타 추진제의 연소속도를 예측하기 위하여 표준모타를 제작하고 지상연소시험을 수행하였다. 이를 위하여 중, 소형 모타의 시험에 적합한 지상연소시험장을 구축하고 경량화된 6 inch 급의 표준모타를 개발하여 여러 차례의 시험에 적용하였고, 메인모타의 연소속도와 비교하였다. 그 결과 표준모타를 이용하는 방법이 기존의 연소속도 측정 방법에 비해 메인모타의 연소속도를 비교적 잘 반영하는 것으로 나타나, 앞으로의 추진제 개발 활동 및 양산품의 품질보증 활동에 적극 활용할 계획이다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.47-53
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• 2006

산화제 과잉 예연소기는 고성능 closed cycle 액체추진로켓 시스템에 적용된다. 이러한 산화제 과잉 연소기는 산화제-연료 혼합비가 약 50이상에서 작동하므로, 예연소기에서 분무특성과 혼합성능이 연소 안정성에 큰 영향을 주게 된다 본 연구에서는 예연소기에 적용 가능한 분사기를 설계하고, 유량측정, 가시화 실험을 수행하여 예연소기 분사기의 분무특성을 연구하기로 한다.

• Journal of Advanced Marine Engineering and Technology
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• 제16권5호
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• pp.6-16
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• 1992

Since world-wide oil shock on 1970s, many large size-low speed diesel engines, instead of steam turbines, are used for the industrial electric power generating plants due to their economic advantage of low specific fuel consumption. But it is very important to control their electric power fluctuation problems for the purpose of smooth parallel operation with existing power plants. In this paper the fluctuation problem of KEPCO Nam-cheju No.1 generator driven by diesel ngine(B & W 7K 60MC, 13931x138.5RPM) is investigated with analysis of torsional vibration of which 4th harmonic component is related to its power fluctuation. The problem can be improved by modification of cylinder arrangement and flywheel position in reverse sequence, equalizing the combustion gas pressure of all cylinder and installation of torsional vibration damper enlarged 30%(Je=7287Kg.m$^{2}$) and high quality balancing of generator rotor.

• Journal of Advanced Marine Engineering and Technology
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• 제36권7호
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• pp.910-918
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• 2012

Carbon monoxide (CO) is a primary air pollutant as an indicator of air quality released from motor vehicle combustion. A comparative study of the distributions of CO concentration with no heat source in two tunnel models open and closed at both end sides is simulated with a commercial CFD code. The tunnel models are used to investigate the CO concentration distributions at three Reynolds numbers, which are computed by the inlet velocities of 0.3, 0.6 and 1.0 m/s. For a better tunnel design, the CFD predictive approaches are available in qualitatively studying the distributions of CO concentration. In the case of the tunnel open at both end sides in sixty seconds, the total CO concentrations are approximately twenty eight percent higher than those in the closed case.

• 한국콘텐츠학회논문지
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• 제10권2호
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• pp.444-451
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• 2010

본 연구는 초정리의 지역이미지통합 전략을 수립하는데 기초가 되는 지역이미지 및 중요요인에 대해 살펴보았다. 연구결과 지역이미지 통합을 위해 중요시 되는 요인은 자연성과 독창성이었으며, 인구통계적 특성에 따라 부분적으로 인식의 차이가 있는 것을 알 수 있었다. 이를 통해 지역이미지 통합을 위해서는 지역 대표자원을 이용해 자연적이면서, 차별화된 이미지통합 전략이 수립되어야 함을 알 수 있었다.

• 한국산업융합학회 논문집
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• 제19권3호
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• pp.154-159
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• 2016

Recently it has been focused that the automobile engine has developed in a strong upward tendency for the use of the high viscosity and poorer quality fuels in achieving the high performance, fuel economy, and emission reduction. Therefore it is not easy to solve the problems between low specific fuel consumption, and exhaust emission control at automotive engine In this study, it is designed and used the test bed which is installed with fuel injector controller. In addition to equipped engine using CRDI by controlling the injection timing with modulator, it has tested and analyzed the engine cycle variation characteristics, as it is varied that they are the operating parameters: fuel injected quantity, injection timing, engine speed and scavenging pressure.

• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.590-596
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• 2014

Wooden cultural heritages of Korea have been destroyed by fire in many cases. As a result, a number of methods to protect wooden cultural properties against fire were introduced. A way of protecting wooden cultural properties installations of fire equipments such as sprinkler, fire alarm system, or fire extinguisher. Another way of protecting wooden cultural properties is to treat them with flame retardants for their safety. Development of a very effective flame retardant with a good performance without affecting danchung and wood quality is required. At the same time, methods of evaluating flame retardant treated woods should be devised to assess their efficacy. In this study, combustion characteristics using cone-calorimeter, limit oxygen index, moisture absorption, iron corrosive and weathering were analyzed to evaluate the flame resistance efficacy and performance of flame retardants treated woods. The evaluation methods of flame retardants for wooden cultural heritage were suggested.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.235-237
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• 2012

Geodae-Uksae 1 is a variety of Miscanthus sacchariflorus recently discovered in Korea. It is being mass-cultivated for use as energy crop due to its superior productivity, as high as 30 ton/ha/yr for the dry mass. This study investigates the method of producing biochar and bio-oil from the crop using slow pyrolysis. Especially, the study focused on assessing the biochar properties for its application to soil to improve soil quality and sequestrate carbon. Using an electrically heated packed bed reactor, the products of slow pyrolysis from Geodae-Uksae 1 were produced over a temperature range of $300-700^{\circ}C$ with a heating rate of $10^{\circ}C/min$. The biochar, condensable vapor (bio-oil) and residual gases were characterized for the physical and chemical properties. It was concluded that the ideal temperature for pyrolysis to produce biochar is $500^{\circ}C$.