• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.331.1-331.1
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• 2016

내부지름이 2.0 mm 이하인 PTFE와 PE 튜브에 진공장치를 이용하여 튜브 내부의 압력을 감압하여 진공상태를 형성하였다. 진공기밀 후에 반응성 가스를 인입하여 튜브 외부에 장착된 전극을 통하여 고전압의 AC 전압을 인가하여 튜브 내부에 선택적으로 유전체 장벽 방전을 유도하였다. 본 연구에서는 유전율이 3.0 이하로 낮은 PTFE와 PE 튜브에 유전체 장벽방전이 유도될 때 나타나는 전압과 전류의 파형을 분석하여 방전의 개시와 방전의 형태를 조사하였다. 주파수 40 kHz인 AC 전원(PEII, Advanced Energy)과 Loadmatch 모듈을 이용하여 4 kV 이하의 전압을 인가하여 플라즈마 방전 유도하였다. 튜브에 인가고전압 프로브와 전류 프로브를 이용하여 오실로스코프를 I-V 분석을 실시하였고, 실험 결과 대기압 방전에서 유도되는 유전체 장벽방전의 I-V 특성과 달리 방전의 형태가 유전체장벽방전과 글로우방전이 혼합된 형태로 나타났다. 또한 유전체 장벽방전을 통해 튜브 내부에 형성되는 플라즈마에 대한 분석으로 OES 광분석을 실시하여, 방전 시간과 전압 변화에 따른 고분자 표면으로부터 방출되는 활성종에 대한 분석을 실시하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.290-293
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• 2012

The analysis and performance evaluation of DBD actuator for plasma flow control was described. The experimental apparatus was designed to measure the flow velocity as the discharge conditions, and to find out the optimal discharge condition of the DBD actuator. The average-velocity increased with increasing the discharge voltage. The experimental results was compared with CFD analysis.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.222-227
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• 2017

This study aimed to explore the potential for food-industry application of atmospheric pressure dielectric barrier discharge plasma (atmospheric pressure DBD plasma) as a non-thermal sterilization technology for microorganism. The effects of the key parameters such as power, oxygen ratio, exposure time and distance on Escherichia coli KCCM 21052 sterilization by the atmospheric pressure DBD plasma treatment were investigated. The experimental results revealed that increasing the power, exposure time or oxygen ratio and decreasing the exposure distance led to an improvement in the sterilization efficiency of E. coli. Furthermore, the atmospheric pressure DBD plasma (1.0 kW power, 1.0% (v/v) $O_2$, 5 min exposure time and 20 mm exposure distance) treatment was very effective for the sterilization of food-borne pathogenic bacteria. The sterilization rate of E. coli, Bacillus cereus KCCM 40935, Bacillus subtilis KCCM 12027, Bacillus thuringiensis KCCM 11429 and Bacillus atrophaeus KCCM 11314 were 72.3%, 74.6%, 88.5%, 84.7% and 91.3%, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.6
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• pp.492-498
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• 2012

Characteristics of DBD(Dielectric Barrier Discharge) plasma actuator as design parameters were investigated for plasma flow control. Flow velocity and power consumption of the DBD plasma actuator were measured according to the design parameters such as discharge voltage and frequency, gap, width and length of electrode, and the thickness of dielectric barrier. The flow velocity and power consumption increased as the discharge voltage and frequency increased. As the electrode gap increased, the flow velocity increased with decreasing the power consumption, whereas high voltage was required for the plasma discharge. The flow velocity increased as the upper-electrode width decreased, and as the lower-electrode width increased at the constant power consumption. The performance of the DBD plasma actuator can be estimated at the given discharge and geometry conditions.

• 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.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.544-550
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• 2013

This work investigated the environmental application of an underwater dielectric barrier discharge plasma reactor consisting of a porous hydrophobic ceramic tube to the decolorization of an azo dyeing wastewater. The reactive species generated by the plasma are mostly short-lived, which also need to be transferred to the wastewater right after the formation. Moreover, the gas-liquid interfacial area should be as large as possible to increase the decolorization rate. The arrangement of the present wastewater treatment system capable of immediately dispersing the plasmatic gas as tiny bubbles makes it possible to effectively decolorize the dyeing wastewater alongside consuming less amount of electrical energy. The effect of discharge power, gas flow rate, dissolved anion and initial dye concentration on the decolorization was examined with dry air for the creation of plasma and amaranth as an azo dye. At a gas flow rate of $1.5Lmin^{-1}$, the good contact between the plasmatic gas and the wastewater was achieved, resulting in rapid decolorization. For an initial dye concentration of $40.2{\mu}molL^{-1}$ (volume : 0.8 L; discharge power : 3.37 W), it took about 25 min to attain a decolorization efficiency of above 99%. Besides, the decolorization rate increased with decreasing the initial dye concentration or increasing the discharge power. The presence of chlorine anion appeared to slightly enhance the decolorization rate, whereas the effect of dissolved nitrate anion was negligible.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.527-528
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• 2012

DBD (Dielectric Barrier Discharge) plasma actuator was designed for aerodynamic drag reduction using plasma flow control, and the drag reduction was measured by wind-tunnel tests using 2D test model. At the zero wind velocity, the plasma flow control had no effect on the drag reduction because the flow separation and surface friction drag were not occurred. At the wind velocity of 2m/s, 9.7% of drag was reduced by the flow separation control. The drag reduction decreased as the wind velocity increased.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.344-351
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• 2023

Purpose: This study aimed to evaluate the effectiveness of a dielectric barrier discharge (DBD) plasma module for sterilizing airborne bacteria in indoor spaces and measure the concentration of ozone generated during plasma discharge. Method: The DBD plasma module was installed in a 76m³ space, and air samples were collected under various discharge times to compare the reduction of airborne bacteria. Result: The results showed a significant decrease in airborne bacteria, ranging from 92.057% to 99.999%, with an average ozone concentration of 0.04 ppm, below the reference value. Conclusion: The study suggests that plasma discharge can be used as a means of preventing the spread of airborne bacteria and viruses, while ensuring safety for human exposure.

• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.281-289
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• 2022

Plasma ozone is utilized in a variety of applications in the field of sterilization due to its high sterilization performance. Dielectric materials used in DBD(dielectric barrier discharges) are mainly polymer, quartz and ceramics. These dielectric layers have the advantage of limiting the amount of supplied electron charge and allowing plasma to occur evenly on the surface of dielectric. Actually, the target or environment for sterilization is often a complex structure, so research and academic study are needed by utilizing the concept of space sterilization. In this study, the device is applied to generate DBD plasma at atmospheric pressure for disinfection due to the effectiveness in producing radicals and ozone. The generator of plasma ozone is a basic structure of dielectric barrier discharge by placing ceramic tube dielectrics and stainless steel electrical conductors at regular intervals. Various applications can be developed based on the proposed design method. Plasma ozone generation for space sterilization device is recognized as an excellent sterilization device. Through the design and verification of the device, we intend to establish an optimal design of the spatial sterilization device and provide the basis data for sterilization applications.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.10
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• pp.1217-1223
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• 2011

In this paper, the dielectric barrier discharge plasma generator has been studied for producing of the high concentration ozone gas. Proposed plasma generator has the structure of extremely narrow discharge air gap(0.15mm) in order to realize the high electric field discharge. We investigate the performance of the dielectric barrier discharge plasma generator experimentally and the results show that the generator has very high ozone concentration characteristics of 13.7[wt%/$O_2$] at the oxygen flow rate of 1[${\ell}$/min] of each discharge cell. So, we confirmed that the proposed plasma generator is suitable for the high concentration ozone production facility of the eco-friendly ozone functional water cleaning system in the electronic components cleaning process.