• Environmental Engineering Research
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• v.11 no.1
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• pp.33-44
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• 2006

The objective of this study was to develop and assess a method for estimating the rain scavenging ratios (RSRs) of particle-bound PAHs and PCBs using measured scavenging ratio of particulate matters (PM) and routinely available data of physico-chemical properties of PM. Paired atmospheric and rainwater sampling was conducted for a total of 4 rain events. Assuming equilibrium partitioning in rainwater-gas-PM system, an equation was derived for estimating the RSR of particle-bound chemicals as a function of RSR of PM and three equilibrium partition constants (i.e. dimensionless Henry's law constant, gas-particle partition coefficient, and water-particle partition coefficient). For all PAHs, the model significantly under-predicted the RSR while the model prediction for PCBs agreed with observation mostly within a factor of 5. The RSR model for the chemicals is of limited use as its accuracy critically depends on how close the observed partitioning of the chemicals in the gas-PM-rainwater system is to that estimated under the equilibrium assumption.

• Environmental Analysis Health and Toxicology
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• v.19 no.1
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• pp.109-117
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• 2004

The purpose of the present study was to examine the effect of diesel exhaust particles on human aortic vascular smooth muscle cells (VSMCs). DNA synthesis, cell viability and morphology of VSMCs after treatment of diesel exhaust particles (DEP) and fine particulate matter (PM$_{2.5}$) were assayed. PM$_{2.5}$ inhibited the DNA synthesis of VSMCs in a concentration -dependent manner, whereat DEP did not affect VSMCs up to 50$\mu\textrm{g}$/mL. These results were confirmed by morphological examination of VSMCs. PM$_{2.5}$ showed a dose-dependent cytotoxicity of VSMCs by MTT assay. Fraction 4 (organic acids) and fraction 8 (moderately polar compounds) showed the most potent inhibition of DNA synthesis of VSMCs, and fraction 7 (slightly polar compounds), fraction 9 (higher polar compounds), and fraction 6 (aromatic compounds) were next order. These results were confirmed by morphological examination of VSMCs. These results suggest that PM$_{2.5}$ inhibits the DNA synthesis of VSMCs through the cytotoxicity.oxicity.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.183-188
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• 2007

Recently, diesel engine has been frequently applied to RV, SUV and light duty truck due to the good fuel economy and high thermal efficiency. $NO_x$ and PM, environmental pollution materials are basically produced in diesel combustion process. The most important target in diesel engine research is the development of system to reduce the emissions of $NO_x$ and PM. Cooled EGR system is an effective method for the reduction of $NO_x$ emission and PM emission from a diesel engine and EGR cooler is the key component of the system. This study investigates the EGR cooler of oval gas tubes compared with the EGR cooler of shell & tubes to verify the heat exchange efficiency of cooler by means of engine dynamometer tests, rig performance tests and numerical analyses.

• Journal of environmental and Sanitary engineering
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• v.18 no.2
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• pp.67-74
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• 2003

In 15 schools where were chosen each location (East, West, South, North, Central) of Seoul area, 9 items were measured such as thermo circumstance(temperature, relative humidity, air current, intensity of illumination) particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide being based on the school indoor environment standard. It was showed that indoor temperature, relative humidity and air movement were suitable in comparison with school indoor environment standard. Intensity of illumination was suitable in comparison with all schools, only exception 2 schools. In all investigated schools were adequate for carbon monoxide, sulfur dioxide and nitrogen dioxide, in which each indoor environment standard (10ppw, 0.25ppm/hr, 0.15ppm/hr), but in 5 schools the carbon dioxide were exceeded for standard limit 1,000ppm of Korea. Indoor concentration of dust(PM-10) induced from respiration dust the standard of Korea ($150{\mu}g/m^3$) at all schools.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.229-230
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• 2003

최근에 대기오염이 심각해지면서 입자상 물질(particulate matter)의 농도가 증가하고 있으며, 이로 인해 대기의 시정뿐만 아니라 건강상의 문제를 일으킬 수 있다는 보고가 늘어나고 있다. 또한 미세 입자는 화학적 조성에 의해 인체에 미치는 영향이 증가할 수 있다. 중량농도 및 무기이온의 농도는 대부분 겨울철에 높으며, 특히 음이온 중에서는 SO$_4$$^{2-}$ , NO$_3$$^{-}$이, 양이온 중에서는 NH$_4$$^{+}$ 이온이 중량농도 중 차지하는 비율이 높다. (중략)

• Journal of the korean Society of Automotive Engineers
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• v.18 no.6
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• pp.33-39
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• 1996

최근 서울의 일부 지역에서는 오존 주의보에 의한 대기 오염의 수치가 발표되고 있어 이의 심각성이 대두되고 있다. 대기오염의 주범은 자동차이며, 자동차에서 주로 많이 배출되는 질소산화물(NOx)과 탄화수소(HC) 및 디젤자동차에서의 입자상 물질(PM: Particulate Matter)등이 대기환경에 미치는 영향이 크므로 이러한 물질의 저감에 대한 요구가 점차 강화되어가고 있다. 특히, 디젤 엔진이 가솔린 엔진에 비해 대기오염의 주원인이라는 편견이 일반적으로 널리 알려져 있지만, 이는 눈에 보이는 Black smoke에 대한 거부반응이 있다는 점이다. 실제로 디젤 엔진의 유해 배출 성분 중에서 NOx는 가솔린과 비슷한 수준이나 HC와 CO성분은 상당히 적게 배출되고 있다. 또한, 디젤 엔진은 연료 경제성 및 지구 온난화의 원인인 CO$_{2}$ 배출이 적다는 장점이 있으므로 디젤 엔진에서 많이 배출되는 성분으로서 입자상 물질(PM) 및 NOx를 줄이는 방안이 요구되고 있다. 이를 저감시키는 방법은 여러가지가 있으나 분사계 측면에서 전자제어식 고압 연료 분사가 요구되고 있으며 이의 개발 필요성에 대해서 논하기로 한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.60-68
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• 2002

Experiments have been conducted to investigate the effects of emulsified fuels on the spray characteristics and exhaust emissions in a diesel engine. Four different fuels were examined : diesel, emulsified fuels with water contents which were varied with 13, 15, and l7wt%. Characteristics of fuel spray were measured by an optical method, PLLIF(planar liquid laser induced fluorescence). Compared to diesel fuel, emulsified fuels which had relatively high kinematic viscosity showed smaller spray angle and longer spray tip penetration. The qualitative droplet distributions of emulsified fuels showed worse atomization process than that of diesel fuel. As the water contents were increased, PM and NOx could be reduced simultaneously. It was specially noted that the emulsified fuel with l7wt% water content was found to be the best in reducing rates, NOx 30% and PM 40%.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.136-142
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• 2000

With the significant growth of the number of vehicles environmental problems is raised. NOx SOx, and PM emissions in diesel powered vehicles are larger than that in gasoline because the development of pollutants reduction techniques has not been yet achieved. So it is need to develop after-tratment or to convert into alternative fuel to satisfy emission regula-tion. Among the after-treatment systems to reduce the diesel emissions studies with diesel oxidation catalyst(DOC) are done greatly. In this study using DOC reduction efficiency with the change of temperature and catalyst loading was calculated through measurements of CO, HC, PM. and SOX.

• Particle and aerosol research
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• v.13 no.4
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• pp.165-172
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• 2017

For precise particle measurements in combustion environments, various dilution sampling methods were compared. Dilution equipments using dilution tunnels and hot/cold dilution with porous tube dilutors were most frequently used so far. The combination of porous tube dilutor and ejector diluter has relatively small footprint, and it results in lower particle losses compared to other methods. To determine the portion of condensable particulate matter, proper temperature control and flow control is required.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.152-157
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• 2006

The air pollutant emission from the railroad diesel locomotive is still a significant environmental concern in many countries including Korea and Unites States. The emission characteristics of the railroad diesel locomotive were extensively studied in this study. Particulate matter (PM) and nitrogen oxides ($NO_x$) emitted from a large locomotive engine (2-cycle, 16-cylinder, and 3,000-horsepower) under various engine-rating conditions was analyzed with a scanning mobility particle sizer and a gas stack sampler by using a dilution tunnel. We could gain the emission values of 2.1 g/horsepower-hour for PM and 42.7 g/horsepower-hour for $NO_x$. We proposed the emission reduction goal of the railroad diesel locomotive for Korea in comparison with the regulation of United States.