• Journal of Environmental Science International
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• v.21 no.4
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• pp.479-488
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• 2012

A Dielectric barrier discharge (DBD) plasma is shown in the present investigation to be effective of phenol degradation in the aqueous solutions in batch reactor with continuous air bubbling. Removal of phenol and effects of various parameters on the removal efficiency in the aqueous solution with high-voltage streamer discharge plasma are studied. The effect of 1st voltage (80 ~ 220 V), air flow rate (3 ~ 7 L/min), pH (3 ~ 11), electric conductivity of solution (4.16 ${\mu}S$/cm, deionized water) ~ 16.57 mS/cm (addition of NaCl 10 g/L) and initial phenol concentration (2.5 ~ 20.0 mg/L) were investigated. The observed results showed that phenol degradation was higher in the basic solution than that of the acidic. The optimum values on the 1st voltage and air flow rate for phenol degradation were 140 V and 6 L/min, respectively. It was considered that absorbance variation of $UV_{254}$ of phenol solution can be use as an indirect indicator of change of the non-biodegradable organic compounds within the treated phenol solution. Electric conductivity was not influenced the phenol degradation. To obtain the removal efficiency of phenol and COD of phenol over 97 % (initial phenol concentration, 10.0 mg/L), 80 min and 120 min were need, respectively. Phenol and COD degradation showed a pseudo-first order kinetics.

• Journal of Environmental Health Sciences
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• v.37 no.3
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• pp.218-225
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• 2011

Objectives: In this paper, a dielectric barrier discharge (DBD) plasma reactor was investigated for degrading the dye Rhodamine B (RhB) in aqueous solutions. Methods: The DBD plasma reactor system in this study consisted of a plasma component [titanium discharge (inner), ground (outer) electrode and quartz dielectric tube], power source, and gas supply. The effects of various parameters such as first voltage (input power), gas flow rate, second voltage (output power), conductivity and pH were investigated. Results: Experimental results showed that a 99% aqueous solution of 20 mg/l Rhodamine B is decolorized following an eleven minute plasma treatment. When comparing the performance of electrolysis and plasma treatment, the RhB degradation of the plasma process was higher that of the electrolysis. The optimum first voltage and air flow rate were 160 V (voltage of trans is 15 kV) and 3 l/min, respectively. With increased second voltage (4 kV to 15 kV), RhB degradation was increased. The higher the pH and the lower conductivity, the more Rhodamine B degradation was observed. Conclusions: OH radical generation of dielectric plasma process was identified by degradation of N, N-dimethyl-4-nitrosoaniline (RNO, indicator of OH radical generation). It was observed that the effect of UV light, which was generated as streamer discharge, on Rhodamine B degradation was not high. Rhodamine B removal was influenced by real second voltage regardless of initial first and second voltage. The effects of pH and conductivity were not high on the Rhodamine B degradation.

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.364-364
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• 2009

• 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.

• Food Science and Preservation
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• v.23 no.7
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• pp.960-966
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• 2016

This study was conducted to explore the potential for use of atmospheric pressure dielectric barrier discharge plasma (atmospheric pressure DBD plasma) as a non-thermal sterilization technology for microorganisms in dried red pepper. The effects of key parameters such as power, exposure time and distance on the sterilization efficiency and the quality of red dried pepper by the atmospheric pressure DBD plasma treatment were investigated. The results revealed that the plasma treatment was very effective for sterilization of Staphylococcus aureus, with 15 min of treatment at 1.0 kW and 20 mm sterilizing 82.6% of the S. aureus. Increasing the power or exposure time and decreasing the exposure distance led to improved sterilization efficiency. The atmospheric pressure DBD plasma treatment showed no effect on the ASTA (American spice trade association) value or hardness of dried red pepper. Furthermore, no effects of atmospheric pressure DBD plasma treatment were observed on the sensory properties of dried red pepper. To assess the storage stability, the dried red pepper was treated with atmospheric pressure DBD plasma (1.5 kW power, 15 min exposure time and 10 mm exposure distance), then stored for 12 weeks at $25^{\circ}C$. Consequently, the ASTA value, hardness and capsaicin concentration of dried red pepper were maintained.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.407-408
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• 2000

유전체 장벽 방전 반응기 (Dielectric Barrier Discharge (DBD) Reactor)를 이용한 비열 플라즈마(Non-thermal plasma) 공정에서 NO 제거 특성을 실험적으로 연구하였다. 질소 분위기에서 전자에 의한 NO 의 제거는 $N_2$ + e $\longrightarrow$ N + N + e 반응에 의한 질소의 전자충돌해리 (electron-impact dissociation)와 이 반응에 의하여 생성된 질소원자에 의한 NO 의 환원반응 N + NO $\longrightarrow$ $N_2$ + O 으로 설명될 수 있으며, 이로 인하여 $O_2$ 나 $H_2O$ 의 첨가에 따른 부산물(O, $O_3$, OH 등)에 의한 산화반응이 주로 일어나는 경우 (XO + NO $\longrightarrow$ X + NO$_2$) 와는 달리 NO 제거에 소모된 에너지를 평가하기에 용이한 장점이 있다(Penetrante et al., 1995). (중략)

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1521-1523
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• 2005

High voltage plasma power supply was adopted to control polluted gases and an ozone generation. Bidirectional pulse power supply consisted of power semiconductor switch devices, a high voltage transformer, and a control board adapted switching method. Plasma power supply with sinusoidal bidirectional pulse, which has output voltage range of 0-20kV and output frequency range of 1kHz-20kHz, is realized. Using proposed system, pulsed high voltage/high frequency discharges were tested in a DBD(dielectric barrier discharge) reactor, and the spatial distribution of a glow discharge was observed. The system showed stable operational characteristics, even though the voltage and the frequency increased. Above features were verified by experiments.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.260-260
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• 2014

Dermatophytes can invade in keratinized tissues and cause dermatophytosis [1] that rank among the most widespread and common infectious diseases world-wide. Although several systemically and topically administered drugs with activities against these fungi are available, still complete eradication of some of these infections, is difficult and relapses and remissions are often observed [2,3]. In addition, some people are allergic to many of the available drugs which add complications even more. Therefore, the search for novel, selective and more effective therapy is always required and it may help the clinicians to choose the correct treatment for their patients. Non-thermal plasmas primarily generate reactive species and recently have emerged as an efficient tool for medical applications including sterilization. In this study, we evaluated the ability of non-thermal dielectric barrier discharge (DBD) plasma for the inactivation of clinical isolates of Trichophyton genera, Trichophyton mentagrophytes (T. mentagrophytes) and Trichophyton rubrum (T. rubrum), which cause infections of nails and skin and, are two of the most frequently isolated dermatophytes [4]. Our results showed that DBD plasma has considerable time dependent inactivation potential on both T. mentagrophytes and T. rubrum in-vitro. Furthermore, the mechanisms for plasma based T. mentagrophytes and T. rubrum inactivation and planning for in-vivo future studies will be discussed.

• Journal of Animal Science and Technology
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• v.54 no.3
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• pp.191-198
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• 2012

The objective of this study was to evaluate the potential use of a dielectric barrier discharge (DBD) plasma system to improve microbial safety of sliced cheese. The atmospheric pressure plasma (APP) effect on visual appearance and a sensory evaluation were also carried out. The number of Escherichia coli inoculated on cheese slices decreased by 0.09, 0.47, 1.16 and 1.47 log cycles with helium (4 liters/min [lpm]) and 0.05, 0.87, 1.89 and 1.98 log cycles with He/$O_2$ mixture (4 lpm/15 standard cubic centimeters per minute), after being treated with plasma for 1, 5, 10, and 15 min, respectively. Significant reductions were also observed in Staphylococcus aureus inoculated onto cheese slices ranging from 0.05 to 0.45 log cycles with He and from 0.08 to 0.91 log cycles with He/$O_2$-treated samples, respectively. Adding oxygen resulted in a significant increase in inactivation of both pathogens. No visible change in the plasma-treated cheese slices was observed even though the instrumental analysis showed a significant decrease in the $L^*$-value and an increase in the $b^*$-value. The cheese slices were damaged after 10 and 15 min of plasma treatment. In addition, significant reductions in sensory quality including flavor, odor, and acceptability of plasma-treated cheese slices were observed. The results indicate that the DBD plasma system has potential for use in sanitizing food products, although the effect was limited. Further development of the APP system is necessary for industrial use.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.391-394
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• 2006

This paper presents soft switching zero voltage switching high frequency inverter for rare gas fluorescent lamp using dielectric-barrier discharge phenomenon. The simple high-frequency inverter can completely achieve stable zero voltage soft switching (ZVS) commutation for wide its output power regulation ranges and load variations under its constant high frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally described and discussed for a constant high-frequency PDM control strategy under a stable ZVS operation commutation, together with its output effective power regulation characteristics-based on the high frequency PDM strategy. The experimental operating performances of this high frequency Inverter are illustrated as compared with computer simulation results and experimental ones. Its light dimming characteristics due to power regulation scheme are evaluated and discussed on the basis of simulation and experimental results. The feasible effectiveness of this high frequency inverter appliance implemented here is proven from the practical point of view.