• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.146-150
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• 2004

The effects on non-thermal plasma generation by duty Ratio and frequency of pulse voltage were investigated experimentally. For these, a new type of non-thermal plasma generator with mesh electrode was manufactured and it was possible to generate the surface and silent discharge simultaneously by new type of non-thermal plasma generator. Duty ratio and frequency were selected as main parameters to control the movement of electron which is mainly related to the non-thermal plasma generation. The characteristics of non-thermal plasma generation were investigated indirectly by measuring the I-V curve and quantity of ozone generation. The most effective condition of duty ratio and frequency to generate the non-thermal plasma was identified by experiments with manufactured non-thermal plasma generator.

• Defense and Technology
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• no.3 s.289
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• pp.66-77
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• 2003

상압플라즈마(APPJ)1)는 반응성이 좋은 이온화된 기체로서 유해한 부산물을 생성해 내지 않고 병원균과 독성 물질의 중화가 가능하며, 저온에서 운용되기 때문에 전자.정밀장비에 손상을 주지 않는 제독무기체계로 활용이 가능한 혁신적인 신기술이다. 아크와 코로나 방전의 장점들만 재조합하여 저압상태에서 반응성이 매우 좋은 입자들을 고밀도로 생성할 수 있으므로 대기압 상태에서 일정한 비열의 플라즈마 방출이 가능한 것으로 판단되다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.1
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• pp.98-103
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• 2001

In this parer, the removal rate of NO in a reactor is rreasured first using nonthermal plasma generated from a wire-cylinder type reactor, then the discharge image and horizontal signal strength and vertical signal strength of NO particles is observed using ICCD(Intensified Charged Coupled Device) carrera It was fOlmd that NO rerroval rate was iflLTeased with NO concentration c1ecreasing, and that honzontal signal strength and vertical signal strength were also increased with NO concentration decreasing. Especially, this research is a1!Tffl at clarifying the discharge mechanism of NO particles by observing the images of AC discharge wnen the nonthermal plasma generated by an discharge was used.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.513-517
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• 2011

The effects of nonthermal plasma treatments against Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes living on polystyrene (PS), sausage casings, and smoked salmon were investigated. Inoculated PS, casings, and salmon were treated with nonthermal plasma generated with helium (5 L/min) or with both helium (5 L/min) and oxygen (100 mL/min) at 60 Hz and 30 kV/cm for 2, 5, or 10 min. S. Typhimurium exhibited the highest sensitivity to the helium-used treatment. The greatest reduction (3.9${\pm}$0.8 log$CFU/cm^2$) was observed with L. monocytogenes on PS after the treatment with the mixed gas for 5 min. The treatment with the mixed gas inhibited L. monocytogenes on casings and salmon by 0.5${\pm}$0.3 log$CFU/cm^2$ and 1.0${\pm}$0.3 log CFU/g, respectively. Different treatment times did not result in different reductions of L. monocytogenes on both casings and salmon. The types of treatment gas and material of contamination need to be considered for evaluating the antimicrobial effects of nonthermal plasma treatments.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.735-741
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• 2013

Effects of cold plasma treatment (CPT) against Salmonella Typhimurium inoculated on cabbage and lettuce, naturally occurring bacteria in black pepper powder and red pepper powder, and Bacillus cereus inoculated onto red pepper powder were investigated. The numbers of S. Typhimurium on cabbage and lettuce were reduced by $1.5{\pm}0.2CFU/cm^2$ (900W, 5 min) and $1.1{\pm}0.1$ log $CFU/cm^2$ (900W, 10 min), respectively. The numbers of naturally occurring aerobic bacteria in both black pepper powder and red pepper powder were reduced by $2.3{\pm}0.3$ and $0.6{\pm}0.2$ log CFU/g, respectively. The numbers of B. cereus vegetative cells on red pepper powder were reduced by $1.5{\pm}0.1$ log CFU/g, but the numbers of spores remained unchanged. The inhibition of S. Typhimurium on cabbage was adequately described by Fermi's model and the Weibull model. The predicted optimum treatment power and time for S. Typhimurium inoculated onto cabbage were 746 W and 6.8 min, respectively. Our results indicate that CPT represents a useful method for microbial decontamination of vegetables and spices.

• Food Engineering Progress
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• v.14 no.3
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• pp.202-207
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• 2010

Low-pressure plasmas (LPPs) were generated with different gases such as air, oxygen and nitrogen, and their inactivation effects against Escherichia coli were compared in order to evaluate the potential as a non-thermal microbial disinfection technology. Homogeneous plasmas were generated under low pressure below 1 Torr at gas flow rate of 350 mL/min regardless the types of gases. Temperature increases by LPPs were not detrimental showing less than ${10^{\circ}C}$ and ${25^{\circ}C}$ increases after 5 and 10 min treatments, respectively. The smallest temperature increase was observed with air LPP, and followed by oxygen and nitrogen LPPs. More than 5 log reduction in E. coli was achieved by 5 min LPP treatment but the destruction effect was retarded afterward. The LPP inactivation was represented by a iphasic first order reaction kinetics. The highest inactivation rate constant was achieved in air LPP and followed by oxygen and nitrogen LPPs. The small D-values of the LPP also supported its potentialities as a non-thermal food surface disinfection technology in addition to the substantial microbial reduction of more than 5 logs.

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.33-46
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• 2000

In the present study, a systematic chemical kinetic calculations were made to investigate the augmentation of NO-$NO_2$ conversion due to the addition of various hydrocarbons (methane, ethylene, ethane, propene, propane) in the nonthermal plasma treatment. It is included in the present conclusion that the reaction between hydrocarbon and oxygen radicals induced by electron collision, is believed to be a primarily process for triggering the overall NO oxidation and the eventual NOx reduction. Upon the completion of the initiating step, various radicals (OH, $NO_2$ etc.) successively produced by hydrocarbon decomposition form the primary path of NO-$NO_2$ conversion. When the initiating step is not activated, hydrocarbon consumption rate appeared to be very low, thereby the targeted level of NO conversion can only be achieved by the addition of more input energy. Present study showed ethylene and propene to have higher affinity with 0 radical under all conditions, thereby both of these hydrocarbons show very fast and efficient NO-$NO_2$ oxidation. It was also shown that propene is superior to ethylene in the aspect of NOx removal.

• 한국연소학회:학술대회논문집
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• 2000.05a
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• pp.178-188
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• 2000

In the present study, a systematic chemical kinetic calculations were made to investigate the augmentation of $NO-NO_{2}$ conversion due to the addition of various hydrocarbons (methane, ethylene, ethane, propene, propane) in the nonthermal plasma treatment. It is included in the present conclusion that the reaction between hydrocarbon and oxygen radicals induced by electron collision, is believed to be a primarily process for triggering the overall NO oxidation and the eventual NOx reduction. Upon the completion of the initiating step, various radicals (OH, $HO_{2}$ etc.) successively produced by hydrocarbon decomposition form the primary path of $NO-NO_{2}$ conversion. When the initiating step is not activated, hydrocarbon consumption rate appeared to be very low, thereby the targeted level of NO conversion can only be achieved by the addition of more input energy. Present study showed ethylene and propene to have higher affinity with 0 radical under all conditions, thereby both of these hydrocarbons show very fast and efficient $NO-NO_{2}$ oxidation. It was also shown that propene is superior to ethylene in the aspect of NOx removal.

• Journal of the Korean Society of Combustion
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• v.5 no.2
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• pp.37-50
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• 2000

In the present study, a systematic chemical kinetic calculations were made to investigate the augmentation of $NO-NO_2$ conversion due to the addition of various hydrocarbons (methane, ethylene, ethane, propylene, propane) in the nonthermal plasma treatment. It is included in the present conclusion that the reaction between hydrocarbon and oxygen radicals induced by electron collision, is believed to be a primarily process for triggering the overall NO oxidation and the eventual NOx reduction. Upon the completion of the initiating step, various radicals (OH, $HO_2$ etc.) successively are produced by hydrocarbon decomposition form the primary path of $NO-NO_2$ conversion. When the initiating step is not activated, hydrocarbon consumption rate appeared to be very low, thereby the targeted level of NO conversion can only be achieved by the addition of more input energy. Present study showed ethylene and propylene to have higher affinity with O radical under all conditions, thereby both of these hydrocarbons show very fast and efficient $NO-NO_2$ oxidation. It was also shown that propylene is superior to ethylene in the aspect of NOx removal.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.320-325
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• 2000

비열플라즈마를 이용한 방전기술(NTPD)은 배기가스로부터 발생되는 NOx와 $SO_2$의 제거에 있어서 최근 혁신적인 후처리 기술중의 하나다 NTPD는 전자빔과 전기적 방전을 사용하여 발생시킬 수 있는데, 두 방법 모두 동일한 기본적인 원리를 갖고 있다. 전기적 에너지의 대부분이 활동적인 전자들을 발생시키는데 이용되고 주위의 가스와 이온들에게는 거의 에너지가 전달되지 않아 효율적이다.(중략)