• Proceedings of the Korea Air Pollution Research Association Conference
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• 2010.04a
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• pp.402-403
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• 2010

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.2
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• pp.131-141
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• 2012

A large fraction of urban $PM_{10}$ concentrations is due to non-exhaust traffic emissions including road dust, tire wear particles, and brake lining particles. Although potential health and environmental impacts associated with tire wear debris have increased, few environmentally and biologically relevant studies of actual tire wear debris have been conducted. Tire wear particles (TWP) are released from the tire tread as a result of the interaction between the tire and the pavement. Roadway particles (RP), meanwhile, are particles on roads composed of a mixture of elements from tires, pavements, fuels, brakes, and environmental dust. The main objective of present study is to identify the contribution of tires to the generation of RP and to assess the potential environmental and health impacts of this contribution. First, a mobile measurement system was constructed and used to measure the RP on asphalt roads according to vehicle speed. The equipment of the mobile system provides $PM_{10}$ concentrations by Dusttrak DRX and number density & size distribution measurements of fine and ultra-fine particles by a fast mobility particle sizer (FMPS) and an aerosol particle sizer (APS). When traveling on an asphalt road at constant speed, there is a clear tendency for $PM_{10}$ concentration to increase slightly in accordance with an increase in the vehicle speed. It was also found that considerable brake wear particles and particles from tire/road interface were generated by rapid deceleration of the vehicle. As a result, the $PM_{10}$ concentration and particle number of ultra-fine particles were measured to be very high.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.6
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• pp.475-486
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• 1997

The characteristics of atmospheric aerosols were investigated as a function of particle size and water solubility. The atmospheric aerosols were sampled with classifying into 12 size ranges by the use of Andersen low-pressure impactor. Collected aerosol particles were extracted by ultrapure water and filtered to be separated into water-soluble and insoluble components. The concentrations 12 elements in both components were determined by PIXE analysis. And the concentrations of 8 ions in the soluble component were analyzed by ion chromatography. In general, the mass size distribution of particulate matter was represented as a bimodal distribution. The mass size distributions of S$(SO_4^{2-}), K(K^+), Zn and NH_4^+$ skewed to the smaller size range and those of Si, Ca$(Ca^{2+}), Fe, Na^+ and Mg^{2+}$ skewed to the larger size range. They had roughly one peak in the fine and coarse particle region,respectively. On the other hand, the mass size distribution of Ti, Mn, Ni, Cu, $Cl^- and NO_3^-$ were represented as the bimodal distribution. Fe and Si in the aerosol particles extracted into pure water are existing in high insoluble state. Conversely, almost the whole of S is dissolved in water.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.126-129
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• 2007

The particle formation using pyrolysis has many advantages over other particle manufacturing techniques. The particles by pyrolysis have relatively uniform size and chemical composition. Also, we can easily produce high purity particles. Thus, we studied the formation of silicon particles by pyrolysis of 50% $SiH_4$ gas diluted in Ar gas. A pyrolysis furnace was used for the thermal decomposition of $SiH_4$ gas at $800^{\circ}C$ and atmospheric pressure. The aerosol flow from furnace is separated into two ways. The one is to the Scanning Mobility Particle Sizer (SMPS) for particle size distribution measurement and the other is to the particle deposition system. The produced silicon particles are deposited on the wafer in the deposition chamber. SEM measurement was used to compare the particle size distribution results from the SMPS. Depending on the experimental conditions, particles of high concentration in the $30\sim80$ nm size range were generated.

• Asian Journal of Atmospheric Environment
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• v.4 no.2
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• pp.72-79
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• 2010

In this study, the ionic composition of volcanogenically derived particles and their temporal and spatial distributions have been investigated to evaluate the impact of the volcanic eruption on the local ecosystem and residents. To this end, an intensive field study was conducted to measure the size-segregated particulate matters at the east part of Sakurajima in Japan. Fractionated sampling of particles into > $PM_{10}$, $PM_{10-2.5}$, and $PM_{2.5}$ was made by a multi nozzle cascade impactor (MCI). The concentration of various ions present in the size-resolved particles was determined by Ion chromatography. The time dependent 3-dimensional Volcanic Ash Forecast Transport And Dispersion (VAFTAD) model developed by the NOAA Air Resources Laboratory (ARL) indicated that the sampling site of this work was affected by the volcanic aerosol particles plume. The temporal distributions of sulfate and $PM_{2.5}$ during the field campaign were significantly variable with important contributions to particle mass concentration. The chlorine loss, suspected to be caused by acidic components of volcanic gases, occurred predominantly in fine particles smaller than $10\;{\mu}m$.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.3
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• pp.321-328
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• 2008

The number of patient with allergic asthma and atopy have increased in the cities of Korea steadily. In order to elucidate the primary factor, we investigated whether the house dust particles collected from an apartment of the middle classes has promoting effects of allergen-related airway inflammation and airway hyperresponsiveness. Mice were treated with 0.1 mL of 1 mg/mL of house dust particles suspension by intratracheal instillation once weekly for 10 weeks combined with ovalalbumin (OVA) sensitization. Intratracheal instillation of house dust particles and OVA sensitization caused an increase in the level of serum L-lactate dehydrogenase (LDH), immunoglobulun-E (IgE) and histamine, and an elevation in respiratory resistance. It also enhanced infiltration of eosinophils in the bronchoalveolar lavage fluid (BALF) of mice, IgE and eotaxin expression in blood, and T helper type 2 cell derived cytokine levels such as of interleukin (IL)-4, IL-13 and IL-5 in the BALF. However, it did not influence T helper type 1 cytokine such as interferon-gamma in the BALF. These results indicate that house dust particles elevate allergen-related airway inflammation and airway hyperresponsiveness in mice and may play an important role in the aggravation of asthma and atopy in Korea.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.6
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• pp.644-655
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• 2012

As soon as a new air filter is applied to an air purification process, the filter gets loaded with dust particles. Thus, the study on the particle loading characteristics of air filter is very essential in order to understand the real filtration phenomena during filter use. In this study, we investigated the effect of particle and filter charge on the particle loading property of air filter. Charged filter and uncharged filter prepared by discharging the charged filter by isopropyl alcohol were used as test samples, and three types of particle having different charge states were supplied to filters tested. For neutralized particles there was a big difference in areal mass loading rates between charged and uncharged filters due to the very small amount of particle charge, on the other hand the difference was diminished for atomized particle and finally almost vanished for corona charged particles. The pressure drop of filter loaded with corona charged particles was only half of those for neutralized and atomized particles at the same areal mass loading because of the porous structure of particle deposit formed on filter fibers, caused by the space charge effect between particles.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.3
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• pp.263-272
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• 1995

Characteristics of anbient at Korean, Cheju Island have been studied during the intensive field study period on March 11 .sim. 17, 1994 in collaboration with other research organizations from Korea and abroad. The particle size distribution was measured using an Electrical Aerosol Analyzer(EAA) and an Optical particle Counter(OPC). Fine particles(PM1 and PM3) have been collected by filter pack samplers and their ionic compositions have been analyzed. sampling errors inherent to the filter pack sampling method are discussed and the method to analyze those errors are presented. The rine mass concentrations of this study show very similar mass concentrations when Seoul is clear. This is somewhat surprising result, because the most of researchers believe that Kosan is one of the cleanest area in Korea. Bimodal volume size distributions with peak values around 0.1 .sim. 0.2.mu.m and 3.mu.m in particle dimeter were observed for most of the measurement period, particle mass loadings and ionic composition data show a large fraction of particles are from non-sea salt origins. Estimation of water content and acidity of particles based on measurement by a gas/particle equilibrium model, SCAPE, reveals that the pH values of particles are comparable to or lower than those estimated based on measurements in Los Angeles, U.S.A. during the SCAQS study. These findings with the meteorological conditions during the study period suggest that the particles collected during the period have originated from outside Cheju Island.

• Particle and aerosol research
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• v.10 no.2
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• pp.75-82
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• 2014

It is necessary to find out the reaction characteristics of $CaCO_3$ sorbent particles in air and $O_2/CO_2$ atmospheric conditions in order that an in-furnace desulfurization technique can be applied to oxy-fuel combustion system. In this study, rate of change of GMD(geometric mean diameter) and specific surface area of $CaCO_3$ sorbent particles reacted in DTF(drop tube furnace) experimental setup were analyzed to investigate the effect of particle size and humidity on the reaction characteristics of them. In air atmospheric condition, calcination process occurs actively within shorter residence times as the particle size increases. On the contrary, in $O_2/CO_2$ atmospheric condition, a calcination process is delayed as particle size increases. The increment of humidity accelerates calcination process in an air atmospheric condition and increase rate of calcination in an $O_2/CO_2$ atmospheric condition.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.358-359
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• 2002

Particulate matter smaller than $10{\mu}textrm{m}$ in aerodynamic diameter (PM10) is known as thoracic particles that are capable of reaching the thoracic region of humans. PM10 is further divided into two size ranges, which are fine particles (nuclei mode plus accumulation mode) and coarse particles, based on different sources and chemical composition. Fine particles can penetrate deep into the alveolar region of the human lungs, while coarse particles be deposited in the upper respiratory system. (omitted)