• 대한예방의학회:학술대회논문집
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• 1994.02a
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• pp.585-595
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• 1994

The region of the respiratory tract where inhaled particles deposit can have important implications for the causation of local or systemic toxic effects. For most aerosols of occupational importance, respiratory tract deposition can be predicted from the aerodynamic diameter of the particles. With the advent of cascade impactors, particularly those of personal sampler size, the determination of the aerodynamic diameters of aerosols has become more common. Some limitations of cascade impactor use are well recognized (e.g., particle bounce and substrate overloading) and are generally correctable. However, two important limitations of the instruments may not be receiving adequate attention: relative humidity effects on potentially hygroscopic aerosols and the collection characteristics of fibrous aerosols as compared to their actual deposition site potential. The results of this study, when compared to results of previous controlled laboratory trials, suggest that, while potentially hygroscopic lead aerosols from lead acid battery plant operations do not appear to be affected by changes in plant environmental humidity levels, the potential - exists for significant size changes upon inhalation. Secondly, fibers were detected in aerodynamic size ranges that would be associated with deep lung deposition; however, upon microscopic examination, these same fibers would actually be predicted to deposit in the upper airways. This study suggests that the physicalchemical properties and morphological features of an aerosol should be carefully considered by industrial hygienists before cascade impactors are used in attempts to predict the effects of inhaled aerosols.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.1
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• pp.44-50
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• 1993

The suspended particulate matters had been collected by a cascade impactor having 9 size fragnated stages for 2 years (Dec. 1989 to Nov. 1991) in Kyung Hee University-Suwon Campus. The particulate matters were then collected on each stage by membrane filters. The weight concentration on each stage was estimated by a microbalance and further chemical element concentrations were determined by an XRF system. The study focused on developing of a receptor model using the TTFA (target transformation factor analysis) to apportion aerosol mass with the 30 ambient data sets. Each data set consists of the 8 size-ranged subdata sets characterized by 13 element variables. Even though a couple of sources could not be identified, three to five sources were extracted from each aerosol size-range, and then 9 statistical source profiles were generated. Finally, source contribution of particulate matters on each size-range could be estimated in Suwon area.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.600-604
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• 2001

The relation between the aerodynamic diameter and some morphological parameters was studied for flame-generated aggregates. $SiO_{2}$ aggregates were generated from $SiCl_{4}$ in premixed methane/air flames. These aggregates were sampled and classified according to their aerodynamic diameter by a cascade impactor; moreover, computer program was developed and tested to find the equivalent area diameter and the fractal dimension of the aggregates. We calculated the parameters from the digitized images of the aggregate TEM micrographs. The aerodynamic diameters of the sampled aggregates were larger than $0.4{\mu}m$ in this experiment. In most cases, fractal dimension of their projection image was very close to 2.0 for these large aggregates. It was found that the equivalent area diameter of these aggregates was approximately three times larger than the Stokes' diameter of them.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.285-286
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• 2003

다단임팩터(cascade impactor)는 대기환경 연구에 있어 입자상물질의 물리ㆍ화학적 분석에 유용하게 사용되고 있는 입자상물질 포집장치이다. 본 연구그룹에서는 분리입경이 각각 10.07, 4.92, 2.49, 1.02, 0.7$\mu\textrm{m}$인 5단 다단임팩터를 이미 개발하여 성능평가를 수행하였으며, 그 연구결과를 발표하였다(Kwon et al., 2003). 또한 개발된 임팩터를 2002년 4월 8일 부터 29일까지 제주도 고산지역에서 실시된 ACE-Asia 측정 기간동안 설치 운영하여 대기 중 에어로졸 샘플링을 하였다(Park et al., 2003). 본 연구에서는 다단임팩터 사용자의 불편을 최소화하고, 장치의 상용화가 가능하도록 최적 설계에 주안점을 두었다. (중략)

• Journal of Biomedical Engineering Research
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• v.30 no.5
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• pp.438-443
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• 2009

Nebulizer is designed to atomize medicinal fluid for patient with small particles(0.5-$5{\mu}m$) and also able to deliver particles from devices to the lungs when patient inhales air. Several particle size measurements are currently used to size aerosol particles. The most commonly used test is the cascade impactor method in as a standard. But, other methods for comparative particle size distribution data such as the particle size range and reproducibility are acceptable. Therefore, in this study a new test methode is suggested for nonventilatory nebulizer evaluation equipment.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.165.2-166
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• 2003

Diesel exhaust is suspected to cause acute and chronic adverse effects on health. In recent. the effect of estrogenic endocrine disruptor in diesel particulate matter was little studied. Therefore, we examined the estrogenic activity of respirable diesel exhaust particulate matter derived from diesel engine motor. PM2.5 diesel exhaust of vehicle was collected using a high volume samples equipped with a cascade impactor. (omitted)

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.3
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• pp.291-298
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• 1995

An intensive field study was carried out during Aug. 1993 in Seoul to study the characteristics of summertime visibility and diurnal trend of ionic composition of ambient particles. A transmissometer, nephelometer with heated and unheated inlets, PM3 fine particle sampler, and cascade impactor were used to measure optical and particle properties of ambient air. During this study period, a weak smog episode has occurred. Light scattering by particles is the most dominant factor on total light extinction. The effect of light absorption by particles in Seoul is much higher than other major cities in U.S.A. throughout the summer and fall with relatively constant values. The effect of water on $b_{sp}$ was small during the period. The particle size distribution shows a typical bimodal one. Sulfate, ammonium, chloride, and nitrate are the major chemical species in fine fraction aerosols, about 30% of toral mass concentration. Concentraion of sulfate is higher during the daytime while those of nitrate and chloride are higher during the nighttime. Ammonium concentration is constant through the daytime.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.1
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• pp.67-77
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• 1996

Total suspended particulate matters (TSP) were collected based on a size segregation method by a cascade impactor for 6 consecutive years (form Dec. 1989 to sep. 1994) in the Kyung Hee University-Suwon Campus, and 6 trace metals (Ca, Si, Fe, Pb, Cu, Zn) were determined by an x-ray fluorescence spectroscopy. Total number of samples collected during the study are 118 sets and each set of sample comsists of 9 filters. The levels of TSP and 6 trace metals were then used to examine seasonal and annual variations with respects to their size distributions. For statistical analyses, raw data were initially transformed by both logarithmic and root transformating to approximately normalize them, and then size distribution functions for each trace element were separately developed season-to-season by a regression analysis in order to obtain maximum amount of physical information, Subsequently, each developed model was verified by comparing with supervised data collected on 1994. The result showed that each prediction model was in good agreement except the fall, partly due to lack of the data collected on fall, 1994.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.11a
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• pp.115-117
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• 2004

제주시 지역 대기부유분진의 입경별 조성특성을 살펴보기 위하여 제주시청 별관 옥상에서 다단계 분진 포집기(8-stage non viable cascade impactor)를 사용하여 대기부유분진을 채취하여 분진의 질량농도 및 수용성 이온성분의 입경분포를 조사하였다. 조사결과 제주시 지역의 대기부유분진은 0.9, 5, $9.5{\mu}m$부근에서 peak를 보이는 삼산형분포(tri-modal distribution)를 나타내었고 $Na^+,\;Ca^{2+},\;Mg^{2+}$ 및 $Cl^-$와 같이 주로 해염에 기인하는 이온 성분들은 $2.1{\mu}m$이상의 조대입자 영역에 존재하고 있었으며 주로 $4{\mu}m$와 $9.5{\mu}m$부근에서 peak를 보였다. $NH_4^+,\;K^+,\;SO_4^{2-}$는 $2.1{\mu}m$이하의 미세입자 영역에 존재하고 있으며 $NO_3^-$의 경우는 계절에 따라 약간의 차이가 있긴 하지만 주로 0.9, 4, $9.5{\mu}m$에서 peak를 나타내고 있다.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E2
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• pp.57-68
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• 2002

Atmospheric dry deposition fluxes and size segregated concentrations of particulate metal elements were measured at four sites in Kunpo, a small city in the Seoul metropolitan area in Korea. At each site, aerosol samples were collected by dry deposition plates, a cascade impactor, and a coarse panicle rotary impactor during four sampling periods. At all sites, the average fluxes of metals measured during daytime were higher than nighttime fluxes due to higher wind speeds and higher ambient concentrations during daytime. The average fluxes of crustal elements (Al, Ca) were 1∼2 orders of magnitude higher than anthropogenic elements (As, Cd, Cu, Mn, Ni, Pb, and Zn). The daytime fluxes of Al and Ca were between 90 and 12000 $\mu\textrm{g}$ m$\^$-2/ day$\^$-1/, and the nighttime fluxes of Al and Ca were between 20 and 2200 $\mu\textrm{g}$ m$\^$-2/ day$\^$-1/. The daytime fluxes of Pb, a typical anthropogenic element, were between 20 and 160$\mu\textrm{g}$ m$\^$-2/ day$\^$-1/, and the nighttime fluxes of Pb were between ND and 100$\mu\textrm{g}$ m$\^$-2/ day$\^$-1/. Also the ambient metal concentrations during daytime were higher than nighttime. Based on a dust emission estimation study in Kunpo, it was found that dust emissions during daytime are higher than nighttime. The concentrations of crustal elements were higher than anthropogenic elements. The distributions of heavy metals were mainly in small particles (D$\_$p/ 9㎛). The fraction of crustal elements in the large particles (D$\_$p/> 9㎛) were higher than anthropogenic elements.