• 한국식품과학회지
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• 제43권4호
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• pp.513-517
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• 2011

PS 필름에 접종된 S. Typhimurium, E. coli O157:H7, L. monocytogenes를 저해시킬 때 헬륨을 사용한 플라즈마 처리의 경우에는 S. Typhimurium이, 헬륨과 산소를 동시에 사용한 플라즈마 처리의 경우에는 L. monocytogenes가 가장 많이 저해되었다. E. coli O157:H7과 L. monocytogenes는 헬륨과 산소를 함께 사용하여 플라즈마 처리하였을 때 헬륨만 사용하였을 때보다 더 큰 저해를 보였다. 헬륨과 산소를 함께 사용한 비열 플라즈마 처리는 L. monocytogenes가 소시지 케이싱이나 훈제연어에 감염되었을 때보다 PS 필름에 감염되었을 때 L. monocytogenes를 더 효과적으로 저해시켜 감염된 재료에 따라 다른 저해 효과를 보여 주었다. 비열 플라즈마 처리에 사용된 가스의 종류와 미생물이 감염된 재료는 그 처리의 항균 효과에 대한 평가에서 중요하게 고려되어야 할 것이다. 헬륨과 산소를 사용한 비열 플라즈마 처리는 공정 후 포장재에 감염된 L. monocytogenes를 효과적으로 저해할 수 있을 것으로 기대된다.

• 공업화학
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• 제22권3호
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• pp.249-254
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• 2011

Ferroelectric의 강유전체 소구들을 충전한 원통형의 비열 방전 플라즈마 반응기를 설계 제작하였으며, 강유전체 층방전 구조를 구성하는 평판(20 mm 간격) 금속망 전극 사이에 직경 2.0 mm인 $SrBiTaO_9$ (SBT) 소구들을 위치시키고 고압의 교류 전원을 인가하였다. SBT 소구는 상온($25^{\circ}C$)에서 150, 큐리온도($335^{\circ}C$)에서 500의 유전상수를 가졌다. 플라즈마 반응기에서 오존 생성속도는 거의 인가전압의 증가에 비례하였으며, SBT 소구들이 충전된 경우, 20 kV 이상의 인가전압에서 오존 생성속도는 급격하게 증가하였다. 부코로나 방전에서 오존 생성속도가 정코로나 방전에서의 경우보다 높았다. 그러나 톨루엔 및 메틸렌클로라이드의 분해율은 생성된 오존 농도에 비례하여 증가하지 않았다.

• 한국대기환경학회지
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• 제16권4호
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• pp.373-380
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• 2000

A new type of photocatalyst plasma air purification filter for decomposition of some VOCs has been developed. The photocatalyst plasma air purification filter employs the pulsed discharge plasma as an energy source of TiO2. photocatalyst instead of UV light. In closed room(2m3) test removal efficiency of some VOCs was 80∼100% in 15∼24 hours. In the initial step of phptocatalyst plasma reaction. Acetone and Nitromethane etc were detected. But they were completely oxidized to CO2 and H2O.

• 한국응용과학기술학회지
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• 제31권4호
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• pp.541-548
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• 2014

This study was performed to obtain high conversion efficiency of $C_7H_8$ using non-thermal plasma and metal-supported catalyst. Adsorption-desorption characteristics of toluene was performed using 4A type (Zeolite) filled in a concentration reactor. Through this test, it was found that the concentration reactor has 0.020 g/g of adsorption capacity (at ambient temperature and pressure) and 3,600 ppm of desorption property at $150^{\circ}C$ (with in 20 min). In case of developed catalyst, toluene decomposition rate of Pd-AO (Pd coated catalyst) was better than Pd/Cu-AO and Pd/Ag-AO (Pd/Ag composite metal catalyst). Developed non-thermal plasma system was obtained flame amplification effect using injection process of desorbed tolune, and 98% of removal efficiency.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.327-327
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• 2011

A nonthermal bioplasma source was developed for application to human liquid fluids by making use of nano-size tungsten tips. Characteristics of the plasma source are investigated. Here we have used the AC voltage system. The bioplasma source generated by a tungsten tip with quartz tube and ground electrode is a low-temperature plasma without making any noticeable damage to cells at a low power operation. The breakdown voltage and current signals are measured by high voltage probe (Tektronix P6015A) and current probe (P6021). Variation of breakdown temperature near the tip electrode is larger than that in the neighborhood of ground electrode. Bubble formation during discharge has been recorded and investigated by using the high speed camera. The existence and behavior of hydroxyl and superoxide radicals are detected and measured by spectrometers. The electrical and optical properties of breakdown characteristics are also investigated.

• 천문학논총
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• 제30권2호
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• pp.545-548
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• 2015

Most high energy cosmic rays (CRs) are thought to be produced by diffusive shock acceleration (DSA) in supernova remnants (SNRs) within the Galaxy. Plasma and MHD simulations have shown that the self-excitation of MHD waves and amplification of magnetic fields via plasma instabilities are an integral part of DSA for strong collisionless shocks. In this study we explore how plasma processes such as plasma instabilities and wave-particle interactions can affect the energy spectra of CR protons and electrons, using time-dependent DSA simulations of SNR shocks. We demonstrate that the time-dependent evolution of the shock dynamics, the self-amplified magnetic fields and $Alfv{\acute{e}nic$ drift govern the highest energy end of the CR energy spectra. As a result, the spectral cutoffs in nonthermal X-ray and ${\gamma}$-ray radiation spectra are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. We also find that the maximum energy of CR protons can be boosted significantly only if the scale height of the magnetic field precursor is long enough to contain the diffusion lengths of the particles of interests. Thus, detailed understandings of nonlinear wave-particle interactions and time-dependent DSA simulations are crucial for understanding the nonthermal radiation from CR acceleration sources.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2000년도 학술대회논문집
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• pp.209-213
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• 2000

In this paper, the removal rate of NO in a reactor is measured first using nonthermal plasma generated from a wire-cylinder type reactor, then the spatial density distribution of NO particles is investigated using ICCD(Intensified Charged Coupled Device) camera. This research uses nonthermal plasma from electrical discharge to analyze the NO characteristics, and the measurements of NO discharge image and Distribution are performed using the ICCD camera to examine the NO characteristics more closely. Furthermore, the method of Laser Induced Fluorescence (LIF) is used to analyze the particular behavior of NO particles more specifically, to suggest a method of reducing exhaust gas, a serious environmental problem.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.259.1-259.1
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• 2014

Recently non-thermal plasma has been frequently applied to various research fields. The liquid plasma have received much attention lately because of interests in surgical and nanomaterial synthesis applications. Especially, intensive researches have been carried out for non-thermal plasma in liquid by using various electrode configurations and power supplies. We have developed a bioplasma source which could be used in a liquid, in which outer insulator has been covered onto the outer electrode. Also we have also put an insulator between the inner and outer electrode. Based on the surface discharge mode, the nonthermal bioplasma has been generated inside a liquid by using an alternating current voltage generator with peak voltage of 12 kV under driving frequency of 22 KHz. Here the discharge voltage and current have been measured for electrical characteristics. Especially, We have measured discharge and optical characteristics under various liquids of deionized (DI) water, tap water, and saline by using monochromator. We have also observed nitric oxide (NO), hydrogen peroxide (H2O2), and hydroxyl (OH) radical species by optical emission spectroscopy during the operation of bioplasma discharge inside various kinds of DI water, tap water, and saline. Here the temperature has been kept to be $40^{\circ}C$ or less when discharge in liquid has been operated in this experiment. Also we have measured plasma temperature by high speed camera image and density by using either H-alpha or H-beta Stark broadening method.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2005년도 추계학술대회 논문집
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• pp.177-178
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• 2005

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2008년도 추계학술대회 논문집
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• pp.194-195
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• 2008