• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.207-210
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• 2004

Effect of electron accepters on anaerobic degradation of petroleum hydrocarbons by an anaerobic sludge taken from a sludge digestion tank in a soil artificially contaminated with 10,000 mg/kg soil of diesel fuel was tested. Treatments of soil with 30 mL of the digestion sludge (2,000 mg/L of vss (volatile suspended solids)) were incubated under several anaerobic conditions including nitrate reducing, sulfate reducing, methanogenic, and mixed electron accepters conditions for 120 days. Treatments with the digested sludge showed significant degradation of diesel fuel under all anaerobic conditions compare to control treatments with an autoclaved sludge and without the sludge. The amount of TPH degradation after 120days incubation was the largest in the treatment with the sludge and mixed electron accepters (75% removal of TPH) followed in order by sulfate reducing, nitrate reducing, methanegenic condition as 67%, 53％, 43%, respectively. However, the rate of TPH degradation in the nitrate- and sulfate reducing condition within 105 days were comparable with that of the mixed electron accepters condition. Microorganisms in each electron acceptor condition were plated on solid mediums containing nitrate or sulfate as sole electron acceptor and several nitrate- and sulfate reducing bacteria showed effective degradation of diesel fuel within 30 days incubations. These results suggest that anaerobic degradation of diesel fuel in soil with digested sludge is effective for practical remediation of soil contaminated with petroleum hydrocarbons.

• 공업화학
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• 제28권6호
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• pp.714-719
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• 2017

연료가 혼합된 엔진오일은 차량의 문제(엔진마모, 화재, 급발진 등)를 초래하여, 운전자의 안전을 위협할 수 있다. 본 연구에서는 연료가 혼합된 엔진오일의 다양한 성능을 분석하였다. 분석결과, 연료혼합 엔진오일은 인화점, 유동점, 밀도, 동점도, 저온 겉보기점도가 낮아졌다. 사구법 내마모성능시험에서는 연료가 혼합된 엔진오일이 열악한 윤활성으로 마모흔(wear scar)이 증가하였다. 또한 우리 연구팀은 ASTM D2887 방법을 적용한 고온모사증류시험(SIMDIST, simulated distillation)을 통해 엔진오일 내 연료성분을 분석하였다. SIMDIST 분석결과 연료는 엔진오일보다 짧은 머무름시간을 보였으며, 엔진오일 내 연료성분의 정량분석이 가능하였다. 이 SIMDIST 분석방법을 통해 기존 많은 분석장비, 시료양, 분석시간이 필요한 물성분석법을 대신하여 엔진오일 내 연료 오염여부 및 정도를 효과적으로 판단할 수 있을 것이다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 제35회 춘계학술대회
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• pp.120-129
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• 2002

New method and device for the on-line measurement of soot concentration in a diesel engine oil are proposed, where the measurement principle is based mainly on attenuated internal total reflection. Various laboratory tests of the detector were performed mainly with carbon black particles of different contamination levels. It was found that the proposed detector could be well used to monitor oil deterioration due to soot contamination. Operational range of the detector was found from 0 to 5 mass percentage of soot content. Test results with water and fuel dilution showed that these effects were not remarkable. However, adsorption of carbon black particles to a measurement surface was considered to be a critical problem in the new detector. Effects of particle deposition onto the interface was experimentally evaluated with the oil temperature and turbulence and discussed throughout this work.

• 한국자동차공학회논문집
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• 제8권3호
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• pp.181-189
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• 2000

The aerodynamic characteristics of large transport vehicle has become more and more important in recent vehicle design to improve driving performance in high speed cruising and raise the product valve with regard to a comfortable driving condition. Hence, detailed knowledge of the flow field around truck coner vane is essential to improve fuel efficiency and reduce the dirt contamination on vehicle body surface. In this study, three-dimensional flow characteristics around corner vane attached to truck cabin were computed for the steady, incompressible, and high speed viscous flow, adopting the RNG k-$\varepsilon$ turbulence model. In order to investigate the influence of configuration and structure of corner vane, computations were carried out for four cases at a high Reynolds number, Re=4.1$\times$106 (based on the cabin height). The global flow patterns, drag coefficient and the distributions such as velocity magnitude, turbulent kinetic energy around the corner vane, were examined. As a result of this study, we could identify the flow characteristics around corner vane for the variation of corner vane length and width. Also, suggest the improved structure to reduce the dirt contamination in cabin side.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1757-1763
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• 2011

In recent years, accordance to industrial development project on railway investment, adverse environmental issues of the investment, such as disputed cases about recycling and usage of Ballast Cleaner excavated soil, have been continuously increasing. It will not only enhance the regulation of soil contamination but take considerable time and cost in future. In this study, we investigated soil contamination and burnability with soil of Chungang Line, Taebaek Line, Chungbuk Line, in order to seize a possibility of recycling Ballast Cleaner excavated soil for the natural materials and substantial heat sources, which are necessary resources for cement manufacturing process. As a result of this study, It is found that Ballast Cleaner excavated soil is satisfied with a standard. The excavated soil contains a lot of cement ingredients and fossil fuel dust incurred from freight transportation, so it is expected to use for ingredients of cement and replacement of heat sources.

• Tribology and Lubricants
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• 제19권5호
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• pp.251-258
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• 2003

New method and device for the on-line measurement of soot concentration in a diesel engine oil are proposed, where the measurement principle is based mainly on attenuated internal total reflection. The detector were evaluated in various ranges of contaminated oils by carbon black particles. It was found that the proposed detector could be well used to monitor the oil deterioration due to soot contamination. Operational range of the detector was found from 0 to 5 mass percentage of soot content. Test results with water and fuel dilution showed that these effects were not remarkable. However, adsorption of carbon black particles onto the measurement surface was considered to be a critical problem of the detector. Effects of particle deposition on the interface was experimentally evaluated with the oil temperature and flow turbulence and discussed throughout this work.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.119-122
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• 2003

Quantitation methods of total petroleum hydrocarbons to determinate oil contaminated level in soil were discussed. Extraction characteristics of several pretreatment methods and practical detection limit and reappearances in gas chromatography/mass spectrometry. with each pretreatment method were investigated. The obtained results showed that the newly adopted quantitation method and mechanical shaking extraction method using methanol with extraction solvent are more practical and applicable to real sample than the conventional methods. In applying these methods to gasoline, kerosene, fuel oil which are major source of soil contamination, the practical quantitation limit and % relative standard deviation was able to determine with range of 2.5 - 10 ppm, 5 - 7 ％.

• 한국수소및신에너지학회논문집
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• 제18권4호
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• pp.432-438
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• 2007

The reforming process for hydrogen production generates some impurities. Impurities in hydrogen such as $CO_2$, CO, $H_2S$, $NH_3$ affect fuel cell performance. It is well known that CO generated by the reforming process may negatively affect performance of cell, cause damage on catalysts resulting performance degradation. Hydrogen produced by reforming process includes about 2% methane. The presence of methane up to 10% is reported negligible degradation in cell performance. However, methane more than 10% in hydrogen stream had not been researched. The concentration of impurity supplied to the fuel cell was verified by gas chromatography(GC). In this study, the influence of $CH_4$ on performance of PEM fuel cell was investigated by means of current vs. potential experiment, long run(10 hr) test and electrochemical impedance measurement when the concentrations of impurities were 10%, 20% and 30%.

• Tribology and Lubricants
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• 제28권2호
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• pp.93-98
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• 2012

The engine oil is an oil used for lubrication of various internal combustion engines. Recently, the vehicle and engine oil manufacture usually guarantee for oil change over 15000~20000 km mileage, but the most of driver usually change engine oil every 5000 km driving in Korea. In this case, it is possible to cause environmental contamination by used engine oil and increase the cost of driving by frequently oil change. In this study, we investigate the various physical properties such as flash point, pour point, kinematic viscosity, cold cranking simulator, total acid number, and four-ball test for fresh engine oil and used engine oil after vehicle driving (5000 km, 10000 km). The test result showed that the total acid number and wear scar by four-ball test of used engine oil had increased than fresh engine oil, but 2 kind of used oil (5000 km and 10000 km) had similar physical properties.

• 동력기계공학회지
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• 제18권6호
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• pp.106-112
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• 2014

The diesel engine, which has high compression ratio than other heat engines, has been using as the main power source of marine transport. Especially, since marine diesel engines offer better specific fuel consumption (SFC), it is environment-friendly compared to those used in other industries. However, attentio should be focused on emissions such as nitrous oxide ($N_2O$) which is generated from combustion of low-grade fuels. Because $N_2O$ in the atmosphere is very stable, the global warming potential (GWP) of $N_2O$ is 310 times as large as that of $CO_2$, and it becomes a source of secondary contamination after photo-degradation in the stratosphere. It has been hitherto noted on the $N_2O$ exhaust characteristics from stationary power plants and land transportations, but reports on $N_2O$ emission from the marine diesel engine are very limited. In this experimental study, a author investigated $N_2O$ emission characteristics by using changed diesel fuel components of nitrogen and sulfur concentration, assessed on the factors which affect $N_2O$ generation in combustion. The experimental results showed that $N_2O$ emission exhibited increasement with increasing of sulfur concentration in fuel. However, all kinds of nitrogen component additives used in experiment could not change $N_2O$ emission.