• Journal of Korean Society for Atmospheric Environment
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• v.26 no.2
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• pp.202-218
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• 2010

It is well known that the atmospheric inorganic aerosol has the hysteresis phenomena depending on the history of relative humidity. However, the current computational researches have assumed that the physical/chemical state of atmospheric aerosol is only determined by a branch of hysteresis, efflorescence or deliquescence. In this work, we applied the MATLAB-based UHAEROm thermodynamics module to simulate the dynamic interaction between gaseous species $NH_3$ and $HNO_3$, and the two mono-disperse particulate populations in the course of efflorescence and deliquescence, respectively. We conducted the 10 case studies considering the particulate phase with the atmospherically prevailing chemical composition and found that the final states of the particles are determined through the qualitatively five different trajectories by the dynamic interaction between gaseous and two different kinds of particulates. As a result, we show that the coexistence of meta-stable and stable particles drives the different physical/chemical destination comparing with the ones generated from the solitary efflorescence or deliquescence branch.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1176-1179
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• 2019

Measurements of activity concentrations of radionuclides in atmospheric releases were performed in 2017-2018 at vent stacks of seven Russian nuclear power plants. The selected instruments and research methods, with detection limits significantly lower than the existing detection limit of Russian NPPs routine control, allowed to reliably determine up to 26 radionuclides. Analysis of experimental data allows to determine the list of radionuclides for calculation the effective dose rates to public and the permissible annual discharge levels for each Russian NPP. Radiocarbon is determined as major contributor for the dose from the atmospheric releases of LWGR reactors - up to 98% for EGP-6 and RBMK-1000 (Smolensk NPP) reactors. For PWR reactors (VVER) radionuclides contribution to the annual dose from atmospheric releases is more complicated, but, in general, dose is formed by tritium, $^{14}C$ and noble gases. The special monitoring results with ranking of measured radionuclides according to their contribution to the effective dose makes it possible to optimize the list of controlled radionuclides in airborne releases of Russian NPPs from 94 to 8-16 for different NPPs.

• Asian Journal of Atmospheric Environment
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• v.5 no.3
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• pp.181-188
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• 2011

Photocatalysis is a photochemical catalytic reaction which is a highly promising tool for the environmental cleanup process. It is very effective in treatment of environmental pollutants by its unique redox property. It has wide applications in the treatment of atmospheric pollutants (e.g., nitrogen dioxide, trichloroethylene, volatile organics, hydrogen sulfide, benzene, etc) through oxidative removal and by disinfection (aeromicro flora). In this research, the fundamental aspects of photocatalysis are described with respect to the composition of catalysts, experimental conditions (e.g., temperature, duration, etc), and interfering factors (e.g., catalyst deactivation).

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.5
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• pp.593-601
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• 2004

In this study, we are going to compare the chemical composition of the precipitation that falls in the Dangjin and Anmyon-do areas by analyzing the water soluble components (anion and cation). We also examined the effects of seasonal change and regional difference in those data sets. The [$NO_3\;^- \;+\;SO_4\;^{2-}$] at 49.2${\mu}$eq/l is 67% of the total anion of 73.1${\mu}$eq/l, while that of [$NH_4\;^+\;+\;Ca^{2+}$] at 37.7${\mu}$eq/l is 62% of the cation in Dangjin area. Also, the [$NO_3\;^-\;+\;SO_4\;^{2-}$] concentration of 151.8 (${\mu}$eq/l) is 62% for the total anion of 143.5 (${\mu}$eq/l), and the [$NH_4\;^+\;+\;Ca^{2+}$] concentration of 119.7 (${\mu}$eq/l) is 47% for the cation of 254.3 (${\mu}$eq/l) in Anmyon-do area. The ion composition ratio is shown for the order by 22% of $SO_4\;^{2-}$, 20.8% of $NH_4\;^+$ and 15.4% of $Cl^-$ that is the sum of 58.7% for the total ion composition in Dangjin area, and is the order by 33.8% of $NH_4\;^+$, 16.3% of $SO_4\;^{2-}$ and 11.1% of $Cl^-$ in Anmyon-do area. Furthermore, We predicted that even areas which were previously clean will get acid rain if there is large scale construction there or nearby.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.423-434
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• 2012

This study was carried out to develop for the emission factor of greenhouse gas (GHG) from medium and smallscaled incineration facility using RPF which is considering as a part of renewable energy in UNFCC. The actual concentration of the exhaust gas and the fuel composition of RPF were measured for the calculation of GHG emission factor in RPF incinerators, and were compared with the IPCC guideline. The $CO_2$ and $N_2O$ emission factors by the actual concentration of exhaust gas were $2.3575{\pm}1.0070tCO_2/tRPF$ and $0.0014{\pm}0.0014tN_2O/tRPF$ respectively. Also, $CO_2$ emission factor by the RPF composition was $2.7057{\pm}0.0540tCO_2/tRPF$. The GHG emission factor per energy by the actual concentration was $83.0867{\pm}26.0346tCO_2e/TJ$ which showed higher consistency with the GHG emission factor ($80.3967tCO_2e/TJ$) of waste plastic in the IPCC guideline (2006b). The $CO_2$ and $N_2O$ emission factor calculated in this study is considered as a meaningful data for GHG emission factor of RPF incineration facility because of not being developed in ROK.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.2
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• pp.175-183
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• 2004

In order to investigate the composition ratio and the emission rate of monoterpenes emitted from coniferous trees during summer, the enclosure chamber experiments were carried out for two tree species (Pinus densiflora and Pinus rigida). The major monoterpenes from the pine trees were $\alpha$-pinene, $\beta$-pinene, myrcene and $\beta$-phellandrene. There was no difference of the composition ratio between two sites for P. densiflora, but the difference was observed for P. rigida. Clearly, the ratio of $\beta$-pinene (26.1 %) for P. rigida was higher than that of $\beta$-phellandrene (12%) at the Gumsung mountain site, but the ratio of $\beta$-phellandrene (22.2%) was higher than that of $\beta$-pinene (9.9%) at the Chiri mountain site. Particularly, the composition ratio of $\beta$-phellandrene was higher than that of $\beta$-pinene for P. densiflora, and the opposite trend was found for P. rigida at the Gumsung mountain site. The characteristics of the composition ratio between two species were similar at the Chiri mountain site. As a result of the emission rate measurements, it was observed that both sites did not show any significant $\beta$ value (slope between emission rate and temperature) and ERs (Standard Emission rate at 3$0^{\circ}C$) difference. However, the $\beta$ value and ERs at the Chiri mountain site were slightly greater than those of Gumsung mountain site for both pine species. P. densiflora (1.703 and 1.971 $\mu\textrm{g}$C/gdw/hr) showed the higher monoterpene ERs than those of P. rigida (0.572 and 0.698 $\mu\textrm{g}$C/gdw/hr) at both sites.

• Analytical Science and Technology
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• v.28 no.3
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• pp.139-159
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• 2015

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.351-353
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• 2005

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.372-374
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.323-325
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• 2008