• Bulletin of the Korean Space Science Society
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• 2000.10a
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• pp.50-50
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• 2000

No Abstract, See Full Text

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.215-216
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.331-332
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• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2009.10a
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• pp.305-308
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• 2009

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.10a
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• pp.69-71
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2010.04a
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• pp.173-174
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• 2010

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.5
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• pp.434-448
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• 2014

The aerosol characteristics between haze episode and Asian dust event were identified in January and March, 2013 in Gwang-ju of Korea to investigate the metal elements, ionic concentrations and carbonaceous particles of $PM_{2.5}$ and $PM_{10}$. In the haze episode, the concentrations were increased 1~3.2 times of ionic species and 1.6~2.7 of metal elements. Especially, the concentration of $NO{_3}{^-}$, $SO{_4}{^2-}$ and $NH{_4}{^+}$ consists of 50 percent in ionic species during haze episode that was higher than Asian dust event. This suggests that secondary aerosols from anthropogenic air pollution were mainly contributed by haze episode. During the Asian dust event, increase of metal concentrations was higher than haze episode because of remarkable increase of Ti, K and Fe originated from soil. The concentrations of carbonaceous particles were increased 2.5 times during haze episode, and 2.4 times of OC and 2.1 times of EC during Asian dust event in $PM_{2.5}$. However, these aerosol mass concentration does not affect the OC/EC ratio. The average equivalence ratios of cations/anions in $PM_{2.5}$ were 0.99 in haze episodes and 0.94 during non-event day. The neutralization factor of $NH_3$ was higher than that of $CaCO_3$. Futhermore, $NH{_4}{^+}$ aerosol was aged due to atmospheric stagnation that might be affected by the haze episode.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.65-73
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• 2014

Objectives: The purposes of this study are to investigate workers' exposures to respirable particles generated in taconite mines and to compare two metric methods for mass concentrations using direct-reading instruments. Methods: Air monitorings were conducted at six mines where subjects have been exposed primarily to particulate matters in crushing, concentrating, and pelletizing processes. Air samples were collected during 4 hours of the entire work shift for similarly exposure groups(SEGs) of nine jobs(N=37). Following instruments were employed to evaluate the workplace: a nanoparticle aerosol monitor(particle size range; 10-1000 nm, unit: ${\mu}m^2/cc$, Model 9000, TSI Inc.); DustTrak air monitors($PM_{10}$, $PM_{2.5}$, unit: $mg/m^3$, Model 8520, TSI Inc.); a condensation particle counter(size range; 20-1000 nm, unit: #/cc, P-Trak 8525, TSI Inc.); and an optical particle counter(particle number by size range $0.3-25{\mu}m$, unit: #/cc, Aerotrak 9306, TSI Inc.). Results: The highest airborne concentration among SEGs was for furnace operator followed by pelletizing maintenance workers in number of particle and surface area, but not in mass concentrations. The geometric means of $PM_{2.5}$ by the DustTrak and the Ptrak/Aerotrak were $0.04{\mu}m$(GSD 2.52) and $0.07{\mu}m$(GSD 2.60), respectively. Also, the geometric means of RPM by the DustTrak and the Ptrak/Aerotrak were $0.16{\mu}m$(GSD 2.24) and $0.32{\mu}m$(GSD 3.24), respectively. The Pearson correlation coefficient for DustTrak $PM_{2.5}$ and Ptrak/Aerotrak $PM_{2.5}$ was 0.56, and that of DustTrak RPM and Ptrak/Aerotrak RPM was 0.65, indicating a moderate positive association between the two sampling methods. Surface area and number concentration were highly correlated($R^2$ = 0.80), while $PM_{2.5}$ and RPM were also statistically correlated each other($R^2$ = 0.79). Conclusions: The results suggest that it is possible to measure airborne particulates by mass concentrations or particle number concentrations using real-time instruments instead of using the DustTrak Aerosol monitor that monitor mass concentrations only.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.751-762
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• 2015

This study was performed to investigate the stability of soil moisture in controlling air ventilation rate within a horizontal biofilter, and to compare removal efficiency (RE) of indoor air pollutants including fine dust, volatile organic compounds (VOCs), and formaldehyde (HCHO), depending on whether dieffenbachias (Diffenbachia amoena) were planted in the biofilter. The relative humidity, air temperature, and soil moisture contents showed stable values, regardless of the presence of D. amoena, and the plants grew normally in the biofilter. REs for number of fine dust particles (PM10 and PM2.5) within the biofilter filled with only soil were at least 30% and 2%, respectively. REs for number of fine dust particles (PM10 and PM2.5) within the biofilter including the plants were above 40% and 4%, respectively. RE for fine dust (PM10) weight was above 4% and 20%, respectively, in the biofilter containing only soil or soil together with plants. In the case of the biofilter filled with only soil, REs for xylene, ethylbenzene, toluene or total VOC (T-VOC) were each more than 63%; however, REs for benzene and formaldehyde (HCHO) were above 22% and 38%, respectively. In the biofilter with the plants, REs for xylene, ethylbenzene, toluene, and T-VOC were each above 72%, and REs for benzene and HCHO were above 39%. Thus, RE of the biofilter integrated with plants was found to be higher for volatile organic compounds than for fine dust. Hence, the biofilter was very effective for indoor air quality improvement and the effect was higher when integrated with plants.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.5
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• pp.227-234
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• 2006

Microstructures of free surface and interior of glass-ceramics obtained by heat treating silicate glass specimen containing electric arc furnace dust(EAF dust) were observed. The crystallization temperature, $T_c$ of glassy specimen was measured around $850^{\circ}C$ from the result of different thermal analysis so heat treatment temperature to obtain glass-ceramic specimen was selected as $950^{\circ}C$ for 1 hr. Glass specimens containing 50 wt% dust were amorphous, while glass specimens containing 70 wt% dust showed spinel crystal peaks in XRD results. In case of glass-ceramic specimens, spinel crystalline phase was appeared with willemite, and willemite crystal peak intensity increased with increasing dust contents. The fractured surface of glass specimens containing 50 wt% dust was smooth like mirror surface, but that containing 70 wt% dust showed spinel crystals of 10 ${\mu}m$ size in glass matrix. In case of glass-ceramic specimens, ZnO crystal particles of $2{\sim}5{\mu}m$ size were produced in free surface and glassy phase, spinel and willemite crystal phases existed in interior. There were no crystals in glasses containing 50 wt% dust, while glass containing 70 wt% dust had 14 vol% crystals. Crystallinity of glass-ceramic specimens containing 50 and 70 wt% dust were 19 and 43%, respectively. When microstructures of glass and glass-ceramic specimens were observed through SEM after TCLP experiment, glass specimens showed flaking phenomenon while glass-ceramic specimens showed a slight corrosion evidence without any cracks.