• Title/Summary/Keyword: barrier discharge

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폴리이미드 필름과 금속의 접촉력 향상을 위한 대기압 플라즈마 표면 연구

  • Seo, Jin-Seok;O, Jong-Sik;Yeom, Geun-Yeong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.335-335
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    • 2012
  • 금속 박막과 PI film 과의 접촉력을 증가시키기 위하여 remote - type modified dielectric barrier discharge (DBD) module을 이용하여 대기압 플라즈마 표면 처리를 실시한 결과, 접촉각이 매우 낮게 형성됨을 관찰 할 수 있었다.

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Spatiotemporal Changes of the Sand Barrier using Marine Charts Analysis in the Nakdong River Estuarine (해도분석을 통한 낙동강 하구 사주 면적의 시.공간 변화)

  • Yoo, Chang-Ill;Yoon, Han-Sam;Ryu, Cheong-Ro;Lee, In-Cheol
    • Journal of Ocean Engineering and Technology
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    • v.20 no.6 s.73
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    • pp.54-60
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    • 2006
  • This study discusses characteristic of spatiotemporal changes of the sand barrier in the Nakdong estuarine for the last century, focusing on geomarphologic evolution and mobility of sand barriers in the view of coastal engineering. The Nakdong estuarine, the research subject, has a complexly changing natural environment by interaction between ground and marine elements such as ocean wave, tidal current, sediment, etc. Moreover, recently, unnatural geomorphologic changes (e.g., seaside reclamation, new harbor construction, etc.) has been radically increased in this area with increasing desire for coastal development. Because of this, its sand barrier has developed quite unstable condition. Therefore, to identify the development process of geomorphologic changes in this area, required is a close examination on historical characteristics of spatiotemporal changes of the sand barrier in relation to surrounding seaside reclamation and physical environmental changes. This study, based on the marine charts published in between 1927 and 1995 year, analyzes the length and area of the sand barrier for the last hundred years, and investigates the cause of the changes by looking into the change of water depth for the last two years and doing ocean-physical site observations. In conclusion, the sand barrier of the Nakdong estuarine expands toward the open sea by $7.4{\sim}26m$ in annual average, maintaining a fixed distance of $1,241{\sim}1.279m$, and its area is expected to increase about $2.8km^2$ annually. This is characterized by the wocean wave from the open sea and the discharge of Nakdong River.

A Study on the Ralstonia Solanacearum Inactivation using Improved Plasma Process (개선된 플라즈마 공정을 이용한 Ralstonia Solanacearum 불활성화에 관한 연구)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.23 no.3
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    • pp.369-378
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    • 2014
  • Effect of improvement of the dielectric barrier discharge (DBD) plasma system on the inactivation performance of bacteria were investigated. The improvement of plasma reactor was performed by combination with the basic plasma reactor and UV process or combination with the basic plasma reactor and circulation system which was equipped with gas-liquid mixer. Experimental results showed that tailing effect was appeared after the exponential decrease in basic plasma reactor. There was no enhancement effect on the Ralstonia Solanacearum inactivation with combination of basic plasma process and UV process. The application of gas-liquid mixing device on the basic plasma reactor reduced inactivation time and led to complete sterilization. The effect existence of gas-liquid mixing device, voltage, air flow rate (1 ~ 5 L/min), water circulation rate (2.8 ~ 9.4 L/min) in gas-liquid mixing plasma, plasma voltage and UV power of gas-liquid mixing plasma+UV process were evaluated. The optimum air flow rate, water circulation rate, voltage of gas-liquid mixing system were 3 L/min, 3.5 L/min and 60 V, respectively. There was no enhancement effect on the Ralstonia Solanacearum inactivation with combination of gas-liquid mixing plasma and UV process.

Comparison of Phenol Removal between Electrochemical Reaction and Plasma Reaction

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.25 no.7
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    • pp.905-916
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    • 2016
  • The characteristics of phenol removal and $UV_{254}$ matters variance were investigated and compared by the variation of operating factors (NaCl concentration, air flow rate, initial phenol concentration) in electrochemical reaction (ER) and dielectric barrier discharge plasma reaction (DBDPR), respectively. The phenol removal rate was shown as $1^{st}$ order both in ER and DBDPR. Also, the absorbance of $UV_{254}$ matters which means aromatic intermediates was analyzed to investigate the complete phenol degradation process. In ER, the phenol degradation and aromatic intermediates production rates increased by the increase of NaCl concentration. However, in DBDPR, the variation of NaCl concentration had no effect on the degradation of phenol and $UV_{254}$ matters. Air flow rate had a little effect on the removal of phenol and the variation of $UV_{254}$ matters in ER. The phenol removal rate in ER was a little higher than that in DBDPR. The produced $H_2O_2$ and $O_3$ amounts in ER were 2 times and 10 times higher than those in DBDPR. The chlorine intermediates ($ClO_2$ and free chlorine) were produced in ER, however, they were not produced in DBDPR.

Removal of NO/SO2 by the low temperature plasmas and photocatalysts (저온 플라즈마와 광촉매에 의한 NO/SO2 제거)

  • Kim, Dong-Joo;Kim, Kyo-Seon
    • Journal of Industrial Technology
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    • v.26 no.A
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    • pp.181-188
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    • 2006
  • In this study, we analyzed the effects of several process variables on the removal efficiencies of NO and $SO_2$ by the dielectric barrier discharge process combined with photocatalysts. The $TiO_2$ photocatalysts were coated onto the spherical-shaped glass beads as dielectric materials by the dip-coating method to analyze the effects of photodegradation reaction on the NO and $SO_2$ removal. As the voltage applied to the plasma reactor increases, or as the pulse frequency of applied voltage increases, the NO and $SO_2$ removal efficiencies increase. Also as the residence time increases, or as the initial concentration of NO decreases, the NO and $SO_2$ removal efficiencies increase. The higher the amount of $TiO_2$ particles coated onto the glass bead is, the larger the surface area of $TiO_2$ particles for the photodegradation reaction is and the NO and $SO_2$ are removed more quickly by the faster photodegradation reactions.

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