• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.779-786
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• 2008

This study was performed to evaluate the characteristics of current air quality and to examine the monthly and yearly variation of $SO_2,\;O_3,\;CO,\;NO_2$, and fine particulate matter(PM-10) concentration in Seosan for the period of 1998-2006. During the recent 3 years, from 2004 to 2006, the yearly mean concentration of $SO_2,\;NO_2$, and PM-10 remained stability but CO and $O_3$ are gradually decreased. The monthly mean concentration of $NO_2$, CO, and $SO_2$ were high in the winter season and decreased steadily to the summer season, but the maximum concentration of $O_3$ and PM-10 appeared in the springtime. The number of days exceeding 24-hour standards for PM-10 were 54 times at Dokgodri and 25 times at Dongmundong. The number of sampling days exceeding the 1-hour and 8-hour standards for $O_3$ were 68 and 210 times at Dongmundong and at Dokgotri 93 and 213 times, respectively.

• Journal of Environmental Science International
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• v.26 no.12
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• pp.1333-1339
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• 2017

Coal-fired power plants emit various Particulate Matter(PM) at coal storage pile and ash landfill as well as the stack, and affect the surrounding environment. Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analyzer(FE-SEM/EDX) were used to develop identification factor and the physico-chemical analysis of PM emitted from a power plant. In this study, three samples of pulverized coal, bottom ash, and fly ash were analyzed. The pulverized coal was spherical particles in shape and the chemical composition of C-O-Si-Al and C/Si and C/Al ratios were 200~300 on average. The bottom ash was spherical or non-spherical particles in shape, chemical composition was O-C-Si-Al-Fe-Ca and C/Si and C/Al ratios were $4.3{\pm}4.6$ and $8.8{\pm}10.0$. The fly ash was spherical particles in shape, chemical composition was O-Si-Ai-C-Fe-Ca and C/Si and C/Al ratios were $0.5{\pm}0.2$ and $0.8{\pm}0.5$.

• Journal of Preventive Medicine and Public Health
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• v.51 no.6
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• pp.275-280
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• 2018

Objectives: The project Seoul Atopy Asthma-friendly School investigated the current status of childhood asthma to enable formulation of a preventative policy. We evaluated the current prevalence of childhood asthma in Seoul and its trends and related factors. Methods: The project was conducted annually from 2011 to 2016 and involved around 35 000 children aged 1-13 years. Based on the International Study of Asthma and Allergies in Childhood guidelines, the survey involved parents. The associations of the particulate matter ($PM_{10}$) concentration, and the number of days on which the daily air quality guidance level was exceeded in the 25 districts of Seoul, with the prevalence of asthma were assessed. Results: The age-standardized asthma prevalence in 2011 and 2016 was 6.74 and 4.02%, respectively. The prevalence of lifetime asthma treatment and treatment during the last 12 months tended to decrease from 2011 to 2016. Asthma treatment was significantly correlated with the number of days on which the daily air quality guidance level was exceeded, but not with the $PM_{10}$ concentration. Conclusions: This study reports the prevalence of asthma among children in Seoul and confirmed the relationship between childhood asthma and known risk factors in a large-scale survey.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.13-25
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• 2021

The particulate matters (PM₁₀ and PM_2.5) and ammonia emitted from livestock farms as dispersed to urban and residential areas can increase the public's concern over the health problem, social conflicts, and air quality. Understanding the atmospheric dispersion of such matters is important to prevent the problems for the regulatory purposes. In this study, AERMOD modeling was performed to predict the dispersion of livestock particulate matters and ammonia in Gwangju metropolitan city and five surrounding cities. The five cities were divided into 40 sub-zones to model the area-based emissions which varied with the number of livestock farms, species and growth stages of the animals. As a result, the concentrations of PM₁₀, PM_2.5 and ammonia resulted from livestock farms located in the surrounding cities were 2.00 ㎍ m^-3, 0.30 ㎍ m^-3 and 0.04 ppm in the southwestern part of Gwangju based on the average concentration of 1 hour. These values accounted for 0.7% of PM₁₀ concentration, 0.5% of PM_2.5 concentration, and 0.4% of the ammonia concentration in Gwangju, contributing to a small amount of air pollution compared to other sources. As preventive measures, the plantation was applied to high emission source areas to reduce particulate matters and ammonia emissions by 35% and 31%, respectively, and resulted in decrease of the area of influence by 57% for particulate matters and 59% for ammonia.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.79-85
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• 2009

Low temperature combustion regime for the simultaneous reduction of nitrogen oxides ($NO_x$) and paticulate matter (PM) is demonstrated in single cylinder engine at various operating parameters, such as EGR rate, injection timing, EGR temperature, amount of fuel and swirl rate. Low temperature combustion is accomplished by high exhaust gas recirculation (EGR) rate in this study. Generally, the emission of $NO_x$ almost completely disappears and PM significantly increases in the first decreasing regime of oxygen concentration but after peaking about 10~12% oxygen concentration, PM then decreases regardless of fuel injection quantity. Low temperature combustion regime was extended by low EGR temperature, high injection pressure and low amount of fuel.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.206-213
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• 2013

Glass eels (Anguilla japonica) are caught in the west coast of Korea on their migratory route from the breeding grounds in the Mariana Trench along the North Equatorial Current and the Kuroshio Current. To identify the food source of natural glass eels, we analyzed the stable C and N isotopes of glass eels caught in April 2012 and investigated possible food sources in the survey area. In particular, with respect to the stable C and N isotopes of particulate organic matter, we extended the surveying area to the northern parts of East China Sea as well as the west coast of Korea. The stable C and N isotope ratios of the glass eels caught in the west coast were found to be $-20.7{\pm}0.1$‰ and $5.0{\pm}0.2$‰, respectively. The stable C and N isotope ratios of the particulate organic matter in the west coast of Korea, in which the glass eels are assumed to eat the particulate organic matter as food source, were estimated to be $-24.0{\pm}0.3$‰ and $2.8{\pm}0.4$‰, respectively. Similar data were obtained from the northern part of the East China Sea, $-24.5{\pm}0.5$‰ and $0.8{\pm}0.3$‰. The stable isotope ratios showed values differing from the stepwise increasing rates up the food web in natural aquatic ecosystem, showing that particulate organic matter in the west coast of Korea and East China Sea was not served as the glass eels food source. This result suggested that the glass eels caught in the west coast might not assimilate nutrition from the marine environment during long migration.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.436-437
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.311-312
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• 2003

다단 임팩터는 수십 나노미터에서 수십 마이크로미터 크기의 대기 에어로졸의 입경분포를 측정하는 장비로 사용되어 왔다. 최근에는 전기적 임팩터가 개발되어 기존 다단임팩터의 문제점인 운전이 번거롭고, 측정시간이 오래 걸리는 단점을 보완하였다. 전기적 임팩터는 실시간으로 에어로졸의 크기분포를 측정할 수 있으므로, 대기환경 모니터링, 디젤 자동차에서 배출되는 입자상 물질(PM, particulate matter)의 측정, 대기오염 방시시설을 구비한 공장, 발전소, 소각로 등의 PM 모니터링 시스템 등에 응용될 수 있다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.157-158
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• 2002

다단임팩터(cascade impactor)는 대기환경 연구에 있어 입자상물질의 물리 화학적 분석에 유용하게 사용되고 있는 입자상물질 포집장치이다. 다단임팩터의 각 단은 외벽(stage wall), 가속노즐판(acceleration nozzle plate)과 충돌판(impaction plate)으로 구성되며 충돌판에는 입자상물질의 포집을 위하여 테플론 필터, 알루미늄 필터 등을 장착하게 되어 있다. (중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.278-284
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• 2006

The popularity of the diesel engine revolves around its fuel efficiency, reliability, and durability compared to the gasoline engine. However, the main disadvantage of diesel engine is the emission of particulate matter (PM) which is known as carcinogenic substance. Therefore recent progress in engine management and after-treatment systems has led to great improvement to satisfy strict emission regulations. To comply with powerful environment regulations, this study is focused on the decrease of PM(soot) as to increase significantly exhaust temperature. Therefore, HC injection is used as the method to go to the PM regeneration temperature in front of filters composed of diesel oxidation catalyst(DOC) and diesel particulate filter(DPF). And especially, LPG is used because it has good chemical reactions with exhaust. In this study, we could manufacture the test bench thought LPG injection - with which soot can be decreased-, construct 3 kinds of database(DB) according to quantity of temperature to decide the LPG injection quantity and develop DPF ECU algorithm.