• Journal of Environmental Science International
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• v.29 no.2
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• pp.177-189
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• 2020

We analyzed the recent characteristics of Particulate Matter (PM) including PM₁₀ (PM with diameter of less than 10 ㎛) and PM_2.5 (PM with diameter of less than 2.5 ㎛) observed in Busan metropolitan area, and compared them with those measured in Seoul metropolitan area. This analysis includes the monthly, seasonal, and annual variations and differences, in emissions and chemical compositions observed in both Busan and Seoul areas. Synoptic meteorological conditions were investigated at the time when high PM concentrations occurred in each of the two areas. The results showed clearly decreasing trends of annual mean concentrations with strong seasonal variations: lower in summer and higher in winter in both areas. In comparison with Seoul, the seasonal variation in Busan demonstrated relatively lower, but showed greater summer fluctuations than in Seoul metropolitan area. This is implying the importance of secondary generation of PM in summer via active photochemical reaction in Busan area. In high concentration days, Busan's chemical composition of sulfate was higher than that of nitrate in summer, whereas nitrate was higher than sulfate in Seoul. The ratios of NO₃^- to SO₄^2-(N/S ratio) showed lower in Busan approximately by a factor of 1/2(half of N/S ratio) in Busan compared with that in Seoul. Others such as synoptic characteristics and emission differences were also discussed in this study.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.40-48
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• 2019

New concept of fine dust measurement method is suggested based on ultrasonic scattering. These days, fine dust has been social problem in Korea, and many researches has been conducted including the area structural maintenance. Conventional measurement system such as optical scattering and semiconductor has a limit from environmental factors like relative humidity. However, ultrasound is based on mechanical waves, which perturb mechanical properties of medium such as density and elastic constants. Using the advantage, the algorithm for fine dust measurement is derived and evaluated using 2-D finite difference method. The numerical analysis simulates ultrasonic wave propagation inside multiple scattering medium like fine dust in air. Signal processing scheme is also suggested and the results show that the error of the algorithm is around minimum of 0.7 and maximum of 24.9 in the number density unit. It is shown that cross-section of fine dust is a key parameter to improve the accuracy of algorithm.

• 대한예방의학회:학술대회논문집
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• 2005.10a
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• pp.407-407
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• 2005

• 대한예방의학회:학술대회논문집
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• 1999.10a
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• pp.98-99
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• 1999

• 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.202-203
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• 2003

디젤 엔진에서 발생되는 입자는 대기 오염의 주 오염원이 되고 있다. 따라서 이를 감소시키기 위해 필터(Diesel Particulate Filter :DPF)를 이용한 다양한 후처리 시스템이 개발되고 있다. DPF 시스템에서 가장 많이 사용하는 필터는 cordierite로 구성된 벌집 모양의 세라믹 필터이다. 그러나 이러한 타입의 필터는 여과시 압력강하가 높을 뿐 아니라 재생을 위한 고온 상태에서 낮은 열전도율로 crack이 일어나거나 melting이 있어 필터 자체의 파손의 위험이 있다. (중략)

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.6
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• pp.803-810
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• 2004

Water contents in fine particles at Seoul and Gosan are estimated by using a gas/particle equilibrium model, SCAPE (Simulating Composition of Atmospheric Particles at Equilibrium). Also, sensitivity of particulate inorganic ionic concentrations on the total ionic species is estimated. Water content at Gosan is more sensitive to ambient relative humidity (RH) than Seoul. At both sites water content is most sensitive to sulfate concentration among sulfate, nitrate, and ammonium. Solid salts levels and compositions are also studied.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.289-292
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• 1999

In recent year, there has been a progressive increase in urban air pollution that is Characterized by high concentrations of atmospheric particulate matter (PM10), resulting primarily from increase of automobils, especially diesel engine powered cars. Although the mechanisms of underling respiratory morbidity due to PM10 are not nuclear, it is thought that the fine particles (PM2.5) are of gratest concern to health since they can be breathed most deeply into the lung, where they are likely to be more toxic than the larger particles.(omitted)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.308-309
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• 2002

대기오염의 주요발생원은 자동차 배기가스, 산업시설 발전소, 배경오염물질이다. 비차량 발생원, 질산화물, 일산화탄소, 차량으로부터 배출되는 일부 미세먼지들의 비교는 과거 30년에 걸쳐 사용되고 있는 전세계 차량의 증가 때문에 불균형하게 증가하였다. 대기질에 있어 인위적인 개선의 건강상 영향을 연구할 기회는 드물다. 월드컵기간동안 서울에서의 대기질 개선을 위한 노력의 일환으로 차량 2부제를 시행은 대도시 교통수단 변화의 영향을 연구할 기회를 제공하였다. (중략)

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.633-640
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• 2000

The effects of structure modification of the vortex finder on the collection efficiency and pressure drop have been investigated. The pressure drop in a cyclone having the two stage vortex finder is higher than that in a conventional cyclone and increases proportionally with the increase of square of gas inlet velocity in both cases. The pressure drop of both conventional cyclone of friction resistance at the boundary layer. The collection efficiency of fine dust has been enhanced by addition of vortex finder in a conventional cyclone and gas inlet velocity showing maximum dust removal efficiency increase to 17 m/s(1.7 times of saltation velocity). Optimum size of two stage vortex finder has been induced to 13 cm I.D$\times$2.6cm Length from the results of overall dust collection efficiency. Previous models were tested for the simulation of collection efficiency of cyclone having two stage vortex finder and the Dietz model predict the similar value with experimental results of the present study.