• Journal of Environmental Health Sciences
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• v.29 no.4
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• pp.10-16
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• 2003

Atmospheric samples were conducted from September 2001 to July 2002 with GPS-l PUF sampler in rural site to concentration distributions of gas/particle PCBs and to calculate dry deposition flux of PCBs. $\Sigma$PCBs concentrations of gas/particle PCBs were 59.29$\pm$48.83, 6.56$\pm$6.59 pg/㎥, respectively. Gas contribution (%) of total PCBs (gas + particle) was 90% which existed gas phase in the atmosphere. The particle contribution (%) of PCB congeners increased relatively more of the less volatile congeners with the highest chlorine number. The correlation coefficients (r) between total PCBs and temperature ($^{\circ}C$) showed negative correlation in - 0.62 (p<0.0l) for particle phase, positive correlation in 0.63 (p<0.01) for gas phase. In other word, particle phase PCBs is enriched in colder weather which could be due to greater in corporation of condensed gas phase at low temperature. The calculated dry deposition of total PCBs (gas + particle) was 0.008, 0.008 $\mu\textrm{g}$ $m^{-2}$ da $y^{-l}$ which showed maximum dry deposition flux in December, minimum data in July Bs in the atmosphere. The calculated dry deposition fluxes of total PCBs were influenced by particle phase PCBs even though PCBs in the atmosphere were present primarily in the gas phase.e.

• Korean Journal of Materials Research
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• v.12 no.8
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• pp.661-668
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• 2002

A study was made to examine the electrical, compositional, structural and morphological properties of Ag thin films deposited by DC magnetron sputtering in $O_2$ atmosphere with deposition temperature from room temperature to 15$0^{\circ}C$ using in-line sputter system. The Ag films deposited at temperature above $100^{\circ}C$ in oxygen atmosphere gave a similar specific resistivity to and even lower oxygen content than those deposited using pure Ar sputter gas The Ag films deposited with pure Ar gas was mainly composed of crystallites with [111] preferred orientation, while, for those deposited in oxygen atmosphere, more than 50% of the volume was composed of crystallites with [100] orientation. The difference in the micro structure did not cause any difference in the specific resistivity of Ag films. The results showed that the transparent conducting oxide films and the Ag films could be processed sequentially in the same deposition chamber with careful control of deposition temperature, which might result in a cost reduction for constructing the large scale in-line deposition system.

• Asian Journal of Atmospheric Environment
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• v.11 no.3
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• pp.202-216
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• 2017

Nitrogen (N) is an essential macronutrient. Thus, evaluating its flows and stocks in rice paddy ecosystems provides important insights into the sustainability and environmental loads of rice production. Among the N sources of paddy fields, atmospheric deposition and irrigation inputs remain poorly understood. In particular, insufficient information is available for atmosphere-rice paddy exchange of gaseous and particulate reactive N (Nr, all N species other than molecular N) which represents the net input or output through dry deposition and emission. In this study, we assessed the N inputs via atmospheric deposition and irrigation to a Japanese rice paddy area by weekly monitoring for 2 years with special emphasis on gas and particle exchange. The rice paddy during the cropping season acted as a net emitter of ammonia ($NH_3$) to the atmosphere regardless of the N fertilizer applications, which reduced the effects of dry deposition to the N input. Dry N deposition was quantitatively similar to wet N deposition, when subtracting the rice paddy $NH_3$ emissions from N exchange. The annual N inputs to the rice paddy were 3.2 to $3.6\;kg\;N\;ha^{-1}\;yr^{-1}$ for exchange, 8.1 to $9.8\;kg\;N\;ha^{-1}\;yr^{-1}$ for wet deposition, and 11.1 to $14.5\;kg\;N\;ha^{-1}\;yr^{-1}$ for irrigation. The total N input, 22.8 to $27.5\;kg\;N\;ha^{-1}\;yr^{-1}$, corresponded to 38% to 55% of the N fertilizer application rate and 53% to 67% of the brown rice N uptake. Monitoring of atmospheric deposition and irrigation as N sources for rice paddies will therefore be necessary for adequate N management.

• Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.167-176
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• 2005

Atmospheric deposition and riverine waters were sampled throughout a year, to estimate the loading fluxes of polycyclic aromatic hydrocarbons (PAHs) into the Masan Bay and its vicinity, Korea. Atmospheric deposition fluxes of total PAHs in the surveyed area varied from 62.2 to 464 ${\mu}g/m^2/year$. Concentration of total PAHs in water samples from six rivers ranged from 34.6 to 239 ng/L. Contribution of the carcinogenic PAHs to the total PAHs occupied $38\%$ and $50\%$ for atmospheric deposition and river waters, respectively. Atmospheric deposition fluxes and water concentrations of PAHs were slightly low or moderate to those in locations from some countries. Correspondence analysis was used to investigate the loading characteristics of PAHs according to transport routes. Atmospheric deposition samples were corresponded to higher molecular aromatics of PAHs, while riverine water samples were associated with lower molecular weight of PAHs. The results indicate that the higher-molecular-weight PAHs can be primarily transported by atmosphere deposition and the lower-molecular-weight PAHs can be mainly contaminated by riverine discharge into the Masan Bay and its vicinity. Loadings fluxes of PAHs into the Masan Bay and its vicinity were 39.2 g/day via atmosphere and 10.3 g/day via rivers, showing that atmospheric input was about 4 times higher than riverine one. Therefore, in order to minimize the contamination burden of PAHs from terrestrial sources to the Masan Bay and its vicinity, the control and management of PAHs deriving from atmosphere will be necessary.

• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.219-223
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• 2006

The thermal decomposition of tetrakis(ethylmethylamido) titanium (TEMAT) has been investigated in Ar and $H_2$ gas atmospheres at gas temperatures of 100-400 ${^{\circ}C}$ by using Fourier Transform infrared spectroscopy (FTIR) as a fundamental study for the chemical vapor deposition (CVD) of titanium nitride (TiN) thin film. The activation energy for the decomposition of TEMAT was estimated to be 10.92 kcal/mol and the reaction order was determined to be the first order. The decomposition behavior of TEMAT was affected by ambient gases. TEMAT was decomposed into the intermediate forms of imine (C=N) compounds in Ar and $H_2$ atmosphere, but additional nitrile (RC$\equiv$N) compound was observed only in $H_2$ atmosphere. The decomposition rate of TEMAT under $H_2$ atmosphere was slower than that in Ar atmosphere, which resulted in the extension of the regime of the surface reaction control in the CVD TiN process.

• Journal of Surface Science and Engineering
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• v.22 no.3
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• pp.118-127
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• 1989

The rate of electrodeposition Zinc-nickel alloy on to electrolytic ione in sulface solution both under an inter and air atmospherss has studied by use of a rotating disc geometry. The kinetics shows 1st order reaction, and the rate constants are proportional to the square root of rpm, however, they are less than the valuse suggested by Levich. The rate constants of zinc deposition approach the total mass transfer rate constants with increasing potential and deviate with increasing rotaing speed, but those of nickel deposition are constant. Below $40^{\circ}C$ the activation engrgies of zinc deposition and nikel deposition were 4.4Kcal/mol and 6.3Kcal/mol respectively. There results show that overall reaction rate of zinc-nickel plaeting is controlled by mixed reaction and zinc deposotion is more affected by mass transfer reaction than nickel. The current density for the zinc-nickel plating was less in an air atmosphere than in a nitrogen atmosphere. The cathode efficiency increased with decreasing cathode rotating speeds, potentials, and increasing temperatures. Zzinc-nickel platings are more improved in microhardnss than zinc platings.

• Nuclear Engineering and Technology
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• v.34 no.3
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• pp.242-249
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• 2002

The relationship between the tritium release rate from the nuclear power plant and tritium concentration in the environment around the Kori site was modeled. The tritium concentration in the atmosphere was calculated by multiplying the release rates and $\chi$/Q values, and the d3V deposition rate at each sector according to the direction and the distance was obtained using a dry deposition velocity. The area around Kori site was divided into 6 zones according to the deposition rate. The six zones were divided into 14 compartments for the numerical simulation. Transfer coefficients between the compartments were derived using site characterization data. Source terms were calculated from the dry deposition rates. Tritium concentration in surface soil water and groundwater was calculated based upon a compartment model. The semi-analytical solution of the compartment model was obtained with a computer program, AMBER. The results showed that most of tritium deposited onto the land released into the atmosphere and the sea. Also, the estimated concentration in the top soil agreed well to that measured. Using the model, tritium concentration was predicted in the case that the tritium release rates were doubled.

• Nuclear Engineering and Technology
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• v.35 no.2
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• pp.171-177
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• 2003

A dynamic compartment model was required for the prediction of radiological consequences of the tritiated vapor released from the nuclear facility after an accident. A computer code, ECOREA-T, was developed by incorporating the unit models for the evaluation of tritium behavior in the environment. Dry deposition of tritiated vapor from the atmosphere to the soil was calculated using a deposition velocity. Transport of tritium from the atmosphere to the plant was calculated using a specific activity model, and the result was compared with the Belot's analytic solution. Root uptake of tritiated water from the soil and formation of OBT from T were considered in the model. The ECOREA-T code was verified by comparing the results from the other computer codes using a scenario developed through BIOMOVS II study. The results showed good agreements.

• Journal of the Korean Society for Heat Treatment
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• v.30 no.1
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• pp.1-5
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• 2017

A 100 nm thick $SnO_2$ thin films were prepared by radio frequency magnetron sputtering on glass substrates and then annealed in nitrogen atmosphere for 30 minutes at 100, 200, and $300^{\circ}C$, respectively. While the visible light transmittance and electrical resistivity of as deposited $SnO_2$ films were 81.8% and $1.5{\times}10^{-2}{\Omega}cm$, respectively, the films annealed at $200^{\circ}C$ show the increased optical transmittance of 82.8% and the electrical resistivity also decreased as low as $4.3{\times}10^{-3}{\Omega}cm$. From the observed results, it is concluded that post-deposition annealing in nitrogen atmosphere at $200^{\circ}C$ is an attractive condition to optimize the optical and electrical properties of $SnO_2$ thin films for the various display device applications.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.5
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• pp.421-432
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• 1998

Deposition processes limit the life time of pollutants in the atmosphere and control the distance travelled before deposition. Thus the understanding about atmospheric deposition processes is essential for a proper assessment of the environmental impacts due to the anthropogenic pollutants. The dry deposition velocities are related to surface types, atmospheric stabilities, friction velocities, air pollutants and so on. In this study we simulated the dry deposition velocities of O3 in Pusan region. The calculated deposition velocities compared to the observed O3 data obtained during the summer of 1988 over a deciduous forest in Canada. The comparison showed that the model somewhat overpredicted deposition velocities for the average diurnal variations with maxima in daytime and minima in nighttime mostly due to the turbulence intensity.