• 한국입자에어로졸학회지
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• 제11권2호
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• pp.29-36
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• 2015

The purpose of this research is to find out the collection property of nanoparticle in diffusion filter to know particle size dispersion of nanomaterial using inertial force and principle of Brownian diffusion motion. We used inertial filters which are two different type and diffusion filters made by various kinds of Wiremesh and the different pieces of filter to compare with particle size distribution using NaCl particles. Finally, We made a conclusion as follows : (1) the bigger available charging volume is and the larger specific surface area of inertial filter is, the better collection efficiency is. (2) The higher wire-mesh number of filter is, the more collection efficiency of small particle is increasing because the wire of the higher Wiremesh number filter is thinner and denser. (3) The more pieces of wire-mesh filter, the more collection efficiency is increasing because it makes the residence time longer.

• 대한기계학회논문집B
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• 제28권7호
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• pp.826-833
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• 2004

Cascade impactors are widely used to collect size classified aerosol. A major disadvantage of this instrument is the required long sampling time. Electrical low pressure impactor has been developed to overcome this disadvantage and to achieve real-time measurements on the particle size distribution. The instrument consists primarily of a corona charger, low pressure cascade impactor and multi channel electrometer. We designed and evaluated the performance of a potable 3-stage low pressure impactor using an electrical method. For the calibration of the impactor, monodispersed particles were generated using evaporation-condensation method followed by electrostatic classification using a DMA(Differential Mobility Analyzer). The collection efficiency curves of the stages can be determined by analysing the fraction of particles collected by each stage.

• 한국입자에어로졸학회지
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• 제17권4호
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• pp.133-148
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• 2021

This study aims to estimate the amount of air pollutants emitted from heavy industry facilities in North Korea. To compare the emission in 2017 from the heavy industry sector in North Korea with South Korea, the heavy industry sector was classified with the South Korean classification (Matching Heavy Industry sector) and air pollutant emissions by Matching Heavy Industry sector in North Korea were estimated. The CO, NO_x and SO_x emissions of Matching Heavy Industry sector in North Korea are 22%, 73%, and 31% of the emission in South Korea, respectively. The air pollutant emissions in the Matching Heavy Industry sector in North Korea for CO, NO_x and SO_x were 0.6%, 124%, and 24% of the total air pollutant emission in North Korea estimated from EDGAR, respectively. As for the distribution of emissions by administrative district of the Matching Heavy Industry sector in North Korea, NO_x was concentrated in the western part of North Korea, and CO and SO_x emissions were concentrated in Hamgyong-bukto.

• 한국대기환경학회지
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• 제13권1호
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• pp.51-63
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• 1997

Total suspended particulate matters in the ambient air were analyzed for eight chemical elements (Ca, Co, Cu, Fe, Mn, Pb, Si, and Zn) using an x-ray fluorescence spectrometry (XRF) at the Kyung Hee University - Suwon Campus during 1989 to 1994. To use these data as basis for source identification study, membership of each sample was selected to represent one of the well defined sample groups. The data sets consisting of 83 objects and 8 variables were initially separated into two groups, fine (d$_{p}$<3.3 ${\mu}{\textrm}{m}$) and coarse particle groups (d$_{p}$>3.3 ${\mu}{\textrm}{m}$). A hierarchical clustering method was examined to obtain possible member of homogeneous sample classes for each of the two groups by transforming raw data and by applying various distances. A disjoint principal component analysis was then used to define homogeneous sample classes after deleting outliers. Each of five homogeneous sample classes was determined for the fine and the coarse particle group, respectively. The data were properly classified via an application of logarithmic transformation and Euclidean distance concept. After determining homogeneous classes, correlation coefficients among eight chemical variables within all the homogeneous classes for calculated and meteorological variables (temperature. relative humidity, wind speed, wind direction, and precipitation) were examined as well to intensively interpret environmental factors influencing the characteristics of each class for each group. According to our analysis, we found that each class had its own distinct seasonal pattern that was affected most sensitively by wind direction.ion.

• 한국대기환경학회지
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• 제18권1호
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• pp.25-37
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• 2002

The purpose of the study was to survey the distribution patterns of inorganic elements of PM-10 in the various indoor environments and analyze the pollution patterns of aerosol in various places of indoor environment using a pattern recognition method based on cluster analysis and disjoint principal component analysis. A total of 40 samples in the indoor had been collected using mini-vol portable samplers. These samples were analyzed for their 19 bulk inorganic compounds such as B, Na, Mg, Al, K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, and Pb by using an ICP-MS. By applying a disjoint principal component analysis, four patterns of the indoor air pollutions were distinguished. The first pattern was identified as a group with high concentrations of PM-10, Na, Mg, and Ca. The second pattern was identified as a group with high concentrations B, Mg, At, Ca, Fe, Cu, and Ba. The third pattern was a group of sites with high concentrations of K, Zn. Cd. The fourth pattern was a group with low concentrations PM-10 and all inorganic elements. This methodology was found to be helpful enough to set the criteria standard of indoor air quality, corresponding pollutants, and classification of indoor environment categories when making an indoor air quality law.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.596-599
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• 2001

Recently, as the environmental pollution becomes an important issue, aerosols which are the main components of the atmospheric pollution become the subject of a lot of researches. An impactor is a kind of sampling and measuring equipment for aerosols since 1970s. The impactor uses coating materials to obtain high performance. However, there are a lot of situations when coating materials are not available and in this case the classification efficiency of the impactor decreases significantly. In this study, the impaction plate of the impactor is cooled, therefore the impactor performs efficiently when coating materials are not available.

• 대한원격탐사학회지
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• 제37권6_2호
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• pp.1891-1900
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• 2021

직경 2.5 ㎛ 이하인 초미세먼지는 급격한 도시화와 인구 증가로 인해 대도시에서 많이 발생하며, 유아 및 청소년기는 성인에 비해 초미세먼지에 취약하고 만성 질환으로 이어질 가능성이 높다. 특히 대부분의 청소년들은 학교에서 가장 많은 시간을 보내고 있으며, 다양한 이유에 의해 실외에서 발생한 초미세먼지가 실내로 유입된다. 본 연구는 외부 요인에 의해 발생하는 학교 초미세먼지를 예측하고 학교별 초미세먼지 범주화를 수행하였다. 10-fold cross validation과 grid-search method를 적용한 random forest (RF) 모델에 화학과 기상 인자, 위성 기반의 aerosol optical depth (AOD)를 입력 자료로 하여 학교 초미세먼지를 예측하고 정확도 평가를 위해 4가지 통계 지표를 이용하였다. 학교 미세먼지 범주화를 위해 6가지 유형을 가진 느슨한 기준과 엄격한 기준을 정의하였으며, 범주화 결과 느슨한 기준의 경우 유형 2와 3에, 엄격한 기준의 경우 유형 3과 4에 가장 많은 학교가 포함되었다.

• 한국입자에어로졸학회지
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• 제14권4호
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• pp.153-169
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• 2018

기존 대기 에어로졸에서의 유기성분 분석은 분석 기기로 파악한 피크 가운데 동정 가능한 성분 개수에 제한이 있었다. 이 문제를 극복하는 방법의 하나로 2DGC를 활용하여 보다 많은 성분을 동정하고, 이들 성분들의 특성 파악을 용이하게 하기 위해 검출된 피크들을 휘발도에 따라 3개, 극성도에 따라 2개로 분리하여 총 6개의 그룹으로 구분하고, 각 그룹의 피크를 정성/정성 분석하여 화학 특성에 따른 클래스로 구분하는 방법론을 제시하였다. 제시한 방법론을 서울에서 2013년 여름과 2014년 겨울에 측정한 대기 에어로졸의 유기 성분을 2DGC로 분석한 결과에 적용하여 특성 파악 연구를 수행하였다. 정성/정량 분석 결과 유기 성분을 8개의 클래스로 구분할 수 있었다. 이 성분들은 계절별 유사성과 차별성을 보여주었다. 한 예로 고극성-휘발성유기화합물(HP-VOC)의 정성분석 결과 여름에는 furanone 성분이 대부분이었으나, 겨울에는 furanone 성분이 검출되지 않았다. 저극성 반휘발성유기화합물(LP-SVOC)의 정성적 특징은 VOC와 OVOC가 대부분을 차지하고 있는 것이었으며 OVOC가 VOC보다 더 많은 종류로 검출되었다. 그러나 상대적 정량분석에서는 반대로 OVOC보다 VOC가 두 배 더 많은 양을 차지하고 있었다. 즉 LP-SVOC에서 OVOC는 더 다양한 종류가 발견되나 정량적으로 봤을 때는 VOC가 대부분을 차지하고 있다고 할 수 있다. 이러한 분석 결과는 보다 다양한 성분의 유기성분 분석과 함께 정성/정량 분석의 통합적 활용이 필요함을 보여주고 있다. 이 연구에서 2DGC 시스템 결과를 6개의 그룹으로 구분하여 미지 성분 피크를 그 그룹의 특성을 가진 것으로 정성/정량 분석하여 어느 정도 결과를 도출하였다. 그러나 각 그룹의 경계에 있는 성분들이 비슷한 특성을 갖는 경우가 나타났고, 정량 분석에는 아직도 미흡한 부분이 있는 제한점을 보였다. 이 부분에 대한 보다 심도 깊은 연구가 필요하다. 또한 2DGC 시스템은 단일 GC 시스템보다 검출 한도가 높은 제한점을 가지고 있으며, 정량이 아직 확실하지 않은 단점이 있다. 이들 문제점을 해결하기 위해서는 분석 시스템 자체에 대한 심도 깊은 연구가 필요하다.

• 한국대기환경학회지
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• 제28권6호
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• pp.688-696
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• 2012

The particle depolarization ratios were retrieved from the observation with a multi-wavelength Raman lidar at Gwangju, Korea ($35.11^{\circ}N$, $126.54^{\circ}E$). The measurements were carried out on 24 February and 9 March 2004. Using the particle depolarization ratios, the non-dust aerosol particles were distinguished from the Asian dust plume, and the proportion of the non-dust particle to total dust plume was retrieved. The calculated proportion of the non-dust particle was used for the retrieval of backscatter coefficients at 355, 532, and 1064 nm and extinction coefficients at 355 and 532 nm of non-dust particles in the dust plume. Microphysical parameters of non-dust particles including single-scattering albedo at 532 nm were retrieved using retrieved optical values. The retrieved single-scattering albedo of non-dust particles was 0.92~0.95 below 1 km height and 0.82~0.91 above 1 km height on 24 February 2004 and $0.81{\pm}0.03$ on 9 March 2004.

• 한국환경보건학회지
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• 제49권6호
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• pp.305-311
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• 2023

Background: The National Institute of Environmental Research (NIER)'s classification of and airborne fraction ratio for consumer chemical products (CCP) does not reflect the characteristics of various product classifications. Objectives: The purpose of this study was to reclassify the types of spray products according to the diverse spray characteristics of CCPs to evaluate the airborne fraction ratio of representative spray types and to compare them with previous CCPs types and airborne fraction ratios. Methods: One thousand seven hundred two products were selected through market research, and 932 newly reported products were selected. After that, 200 were selected to evaluate products with potential inhalation exposure. After classifying six product types that are expected to show differences in the airborne fraction ratio according to the type of product, a final 38 products were selected for use in the airborne fraction ratio through random sampling. Results: CCP has been reclassified from two to six types so that the characteristics of all products are well-reflected. The NIER simply had two airborne fraction ratios, but the results of experiments with six types of products showed a significant difference in values (p<0.01). Airborne fraction ratios of propellant general foam, pump general aerosol, and pump trigger foam in spray type, which were not previously present in NIER, were 7.1%, 24.4%, and 3.5%, respectively. Conclusions: For the diversified types of CCPs, the newly proposed classification was more appropriate than the existing NIER classification. The airborne fraction ratio was also different for each type, so a new value was suggested.