• 한국입자에어로졸학회지
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• 제5권4호
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• pp.179-188
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• 2009

The dry deposition fluxes of particulate polychlorinated biphenyls (PCBs) were measured along with their mass size distributions at Seoul and Incheon in fall in 1999. The dry deposition fluxes of PCBs were in the range of $16.7{\sim}62.2ng/m^2/day$. The ambient concentrations of particulate PCBs were in the range of 0.07 to $0.20ng/m^3$. Generally, the mass size distribution of particulate PCBs shows bi-modal distribution. The mass fraction of PCBs in the fine particle fraction ($D_p<2.1 {\mu}m$) was over than 55% of the total PCBs concentrations. It was found that Seoul and Incheon were not the major source of PCBs emissions in Korea. Based on the comparison with the measurement data in summer, 1999, it is likely that both the dry deposition fluxes and ambient particulate PCBs concentrations were not site-specific.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.849-853
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• 2018

Mechanistic calculations for wet scrubbing of aerosol/vapor from gas bubble rising in liquid pool are essential to safety of sodium-cooled fast reactor. Hence, scrubbing of volatile fission product from mixed gas bubble rising in sodium pool is presented in this study. To understand this phenomenon, a theoretical model has been setup based on classical theories of aerosol/vapor removal from bubble rising through liquid pools. The model simulates pool scrubbing of sodium iodide aerosol and cesium vapor from a rising mixed gas bubble containing xenon as the inert species. The scrubbing of aerosol and vapor are modeled based on deposition mechanisms and Fick's law of diffusion, respectively. Studies were performed to determine the effect of various key parameters on wet scrubbing. It is observed that for higher vapor diffusion coefficient in gas bubble, the scrubbing efficiency is higher. For aerosols, the cut-off size above which the scrubbing efficiency becomes significant was also determined. The study evaluates the retention capability of liquid sodium used in sodium-cooled fast reactor for its safe operation.

• 한국대기환경학회지
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• 제22권4호
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• pp.477-486
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• 2006

Dry deposition fluxes for $SO_2$, particulate sulfate, nitrate, ammonium and $HNO_3$ were estimated in urban area for the time period January$\sim$ October 2005. Fluxes were generated using atmospheric concentration data collected both in Acid Deposition and Air Quality Monitoring Networks, and deposition velocities computed by combining land-use data with meteorological information. The resulting annually averaged $SO_2$, $NO_3$, and aerosol deposition velocities were found to be 0.4 cm/s, 4.3 cm/s and 0.1 cm/s, respectively, and thus deposition rates were 4.4 mg/$m^2$. day for $SO_2$, and 5.4 mg/$m^2$ . day for $NHO_3$, and particulate sulfate, ammonium and nitrate recorded 1.0 mg/$m^2$ . day, 0.4 mg/$m^2$ . day and 0.4 mg/$m^2$ day, respectively. Maximum for in seasonal variation of monthly averaged deposition velocities occurred in summer in contrast to $HNO_3$ showing peak in spring. There was no significant variation for aerosol. The dry to total (wet and dry) deposition contributed about 40% for sulfur and 28% for nitrogen species in this study.

• Asian Journal of Atmospheric Environment
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• 제7권1호
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• pp.8-16
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• 2013

The fog water chemistry and deposition in northern Japan were investigated by fog water and throughfall measurements in 2010. Fog water was sampled weekly by an active-string fog sampler at Lake Mashu from May to November. Throughfall measurements were conducted using rain gauges under three deciduous trees along the somma of the lake from August to October. The mean fog deposition rate (flux) was calculated using throughfall data to estimate the total fog water deposition amount for the entire sampling period. $NH_4{^+}$ and $SO{_4}^{2-}$ were the most abundant cation and anion, respectively, in the fog water samples. A mean pH of 5.08 in the fog water, which is higher than those in rural areas in Japan, was observed. The [$NH_4{^+}$]/[$SO{_4}^{2-}$] equivalent ratio in fog water was larger than 1.0 throughout the study period, indicating that $NH_3$ gas was the primary neutralizing agent for fog water acidity. The mean rate and total amount of fog water deposition were estimated as 0.15 mm $h^{-1}$ and 164 mm, respectively. The amounts of nitrogen and sulfate deposition via fog water deposition were corresponded to those reported values of the annual deposition amounts via rainfall.

• 한국세라믹학회지
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• 제40권8호
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• pp.715-719
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• 2003

The Aerosol Deposition (AD) process will be proposed as a new fabrication technology for the integrated RF modules. $\alpha$-A1$_2$O$_3$ thick films were successfully grown on glass and Al substrates at room temperature by the AD process. Relative dielectric permittivity and loss tangent of the $Al_2$O$_3$ thick films on Al showed 9.5 and 0.005, respectively. To form microstrip lines on aerosol-deposited A1903 thick films, copper electroplating and lithography processes were employed, and the square-type cross section with sharp edges could be obtained. Low-pass LC filters with 10 GHz cutoff frequency were simulated by an electromagnetic analysis, exhibiting the validity of the AD process as a fabrication technology f3r integrated RF modules.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제37회 하계학술대회 초록집
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• pp.326-326
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• 2009

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제37회 하계학술대회 초록집
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• pp.296-296
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• 2009

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제37회 하계학술대회 초록집
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• pp.297-297
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• 2009

• 세라미스트
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• 제12권3호
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• pp.22-29
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• 2009

• Transactions on Electrical and Electronic Materials
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• 제14권4호
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• pp.165-171
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• 2013

Nanostructured pure a-C and nitrogen doped a-C: N thin films with small particle size of, ~50 nm were obtained by Aerosol-assisted CVD method from the natural precursor camphor oil. Five samples were prepared for the a-C and a-C: N respectively, with the deposition temperatures ranging from $400^{\circ}C$ to $600^{\circ}C$. At high temperature, the AFM clarifies an even smoother image, due to the increase of the energetic carbon ion bombardment at the surface of the thin film. An ohmic contact was acquired from the current-voltage solar simulator characterization. The higher conductivity of a-C: N, of ${\sim}{\times}10^{-2}Scm^{-1}$ is due to the decrease in defects since the spin density gap decrease with the nitrogen addition. Pure a-C exhibit absorption coefficient, ${\alpha}$ of $10^4cm^{-1}$, whereas for a-C:N, ${\alpha}$ is of $10^5cm^{-1}$. The high ${\sigma}$ value of a-C:N is due to the presence of more graphitic component ($sp^2$ carbon bonding) in the carbon films.