• 한국연소학회:학술대회논문집
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• 2003.12a
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• pp.27-32
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• 2003

The effect of non-thermal plasma on diffusion flames in co-flow jets has been studied experimentally by adopting a dielectric barrier discharge technique. The generation of streamers was enhanced with a flame due to increased reduced electric fields by high temperature burnt gas and the abundance of ions in the flame region. The effect of streamers on flame behavior reveals that the flame length was significantly decreased as the applied voltage increased and the yellow luminosity by the radiation of soot particles was also significantly reduced. The formation of PAH and soot was influenced appreciably by the non-thermal plasma, while the flame temperature and the concentration of major species were not influence much with the plasma generation. The results demonstrated that the application of non-thermal plasma can be a viable technique in controlling soot generation in flames with low power consumption in the order of 1 W.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.2
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• pp.157-165
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• 2003

A combined process of non-thermal plasma and catalytic technique has been investigated to treat $CH_3$CN gas in the atmosphere. A planar type dielectric barrier discharge (DBD) reactor has been used to generate the non-thermal plasma that produces various chemically active species, such as O, N, OH, $O_3$, ion, electrons, etc. Several different types of the beads. which are Molecular Sieve (MS) 5A, MS 13X, Pt/alumina beads, are packed into the DBD reactor, and have been tested to characterize the effects of adsorption and catalytic process on treating the $CH_3$CN gas in the DBD reactor. The test results showed that the operating power consumption and the amounts of the by-products of the non-thermal plasma process can be reduced by the assistance of the adsorption and catalytic process.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.3
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• pp.105-112
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• 2002

A combined process of non-thermal plasma and catalytic techniques has been investigated to treat toxic gas compounds in air. The treated gas in the present study is $CH_3$CN that has been known to be a simulant of toxic chemical agent. A planar type dielectric barrier discharge(DBD) reactor has been used to generate non-thermal plasma that produces various chemically active species, O, N, OH, $O_3$, ion, electrons, etc. Several different types of adsorbents and catalysts, which are MS 5A, MS 13X, Pt/alumina, are packed into the plasma reactor, and have been tested to save power consumption and to treat by-products. Various aspects of the present techniques, which are decomposition efficiencies along with the power consumption, by-product analysis, reaction pathways modified by the adsorbents and catalysts, have been discussed in the present study.

• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.183-189
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• 2007

We have investigated the oxidation of gas phase elemental mercury using dielectric barrier discharge (DBD). In the DBD process, active species such as $O_3$, OH, O and $HO_2$ are generated by collisions between electrons and gas molecules. Search active species convert elemental mercury into mercury oxide which is deposited into the wall of DBD reactor because of its low vapor pressure. The oxidation efficiency of elemental mercury has been decreased from 60 to 30% by increasing the initial concentration of the elemental mercury from 72 to $655{\mu}g/Nm^3$. The gas retention time at the DBD reactor has showed the little effect on the oxidation efficiency. The more oxygen concentration has induced the more oxidation of elemental mercury, whereas there has been no appreciable oxidation within pure $N_2$ discharge. It has indicated that oxygen atom and ozone, generated in air condition determine the oxidation of elemental mercury.

• 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 Korean Society of Occupational and Environmental Hygiene
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• v.29 no.3
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• pp.414-419
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• 2019

Objectives: The objective of this study was to evaluate the inhibitory effect of non-thermal dielectric barrier discharge (DBD) plasma by air volume against Mycobacterium tuberculosis (MTB). Methods: Plasma generators (TB-300, Shinyoung Airtec, Seongnam-si, Korea) were operated in a 2A type biosafety cabinet. The plasma generator was set to a wind flow rate of 14 ($80m^3/h$), 18 ($110m^3/h$), and 22 ($150m^3/h$), and exposure times were set to 0 hours, 3 hours, 6 hours, 9 hours, and 24 hours. Results: The inhibitory effects of plasma at air volume 14 with prolonged exposure time of three hours was 20%, 64% at six hours, 82.3% at nine hours, and 100% after 24 hours exposure. With air volume of 18, the inhibitory effects upon plasma exposure were 36% for three hours, and 100% from 24 hours. Greater air volume resulted in greater inhibition of tuberculosis bacterial growth. In particular, the maximum inhibitory effect (100%) was shown in air volume of 22 ($150m^3/h$) after three hours of plasma exposure. Conclusions: The results showed the correlating inhibitory effects of plasma on the growth of MTB in combination with increasing plasma exposure time and air volume.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.5
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• pp.717-720
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• 2012

Various types of dielectric-barrier-discharge (DBD) devices have been developed for diverse applications for the last decade. In this study, a flat non-thermal DBD micro plasma source under atmospheric pressure has been developed. The flat-panel type plasma is generated by bipolar pulse voltages, and driving gas is air. In this study, the plasma source was investigated with intensified charge coupled device (ICCD) images and Optical Emission Spectroscopy (OES). The micro discharges are generated on the crossed electrodes. For theoretical analysis, 2-dimensional fluid simulation was performed. The plasma source can be driven in air, and thus the operation cost is low and the range of application is wide.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.117-121
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• 2006

Non-thermal plasma technology has many applications in various areas. One of the applications is regenerating diesel particulate filter (DPF). DPF is a widely applied device to control the particulate emission of diesel engines. But it needs periodic removal of clogged soot for the smooth running of engine. Conventional high-temperature removal processes easily leads to the breakage of DPF. Herein, low-temperature plasma formed in a dielectric barrier discharge (DBD) reactor was used to form active oxidants such as ozone and nitrogen dioxide. Experimentally, the effects of discharge power and frequency on the performance of DBD reactor were studied. Two oxidants, $O_3$ and $NO_2$, were synthesized and used for incinerating soot in the used DPF. Performances of the two oxidants on the reduction of soot were compared, and it was found that $NO_2$ is more effective than $O_3$ for getting rid of soot

• Journal of Environmental Science International
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• v.21 no.5
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• pp.597-603
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• 2012

Non-thermal plasma processing using a dielectric barrier discharge (DBD) has been investigated as an alternative method for the degradation of non-biodegradable organic compounds in wastewater. The active species such as OH radical, produced by the electrical discharge may play an important role in degrading organic compound in water. The degradation of N, N-Dimethyl-4-nitrosoaniline (RNO) was investigated as an indicator of the generation of OH radical. The DBD plasma reactor of this study consisted of a plasma reactor, recycling pump, power supply and reservoir. The effect of diameter of external reactor (15 ~ 40 mm), width of ground electrode (2.5 ~ 30 cm), shape (pipe, spring) and material (copper, stainless steel and titanium) of ground electrode, water circulation rate (3.1 ~ 54.8 cm/s), air flow rate (0.5 ~ 3.0 L/min) and ratio of packing material (0 ~ 100 %) were evaluated. The experimental results showed that shape and materials of ground were not influenced the RNO degradation. Optimum diameter of external reactor, water circulation rate and air flow rate for RNO degradation were 30 mm, 25.4 cm/s and 4 L/min, respectively. Ground electrode length to get the maximum RNO degradation was 30 cm, which was same as reactor length. Filling up of glass beads decreased the RNO degradation. Among the experimented parameters, air flow rate was most important parameters which are influenced the decomposition of RNO.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.910-916
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• 2022

The purpose of this study is to evaluate the effect of underwater non-thermal dielectric barrier discharge plasma (DBD plasma) on the sterilization of three types of pathogenic bacteria that cause diseases in freshwater fish and the reduction of a tetracycline antibiotics. This experiment was conducted in the DBD plasma generator, and the voltages used to generate plasma were 11.6 kV and 23.1 kV. The measurement intervals were 0, 1, 5, 10 and 15 min. As a result of DBD plasma treatment, Aeromonas hydrophila, Edwardsiella tarda and Pseudomonas fluorescens were removed 93-99% after 5 min at 23.1 kV, and the tetracycline antibiotics were reduced 70-95% after 15 min at 23.1 kV. In this study, as a result of treating the effluent with DBD plasma at a fish farm where the medicinal bath was conducted with oxytetracycline-HCl (OTC-HCl) products, OTC-HCl decreased by 62% after 10 min at 23.1 kV.