• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.155.1-155.1
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• 2015

Nowadays, Plasma has been used in biological, medical such as wound healing, plant grow, killing cancer. When plasma generated, UV light and ROS(Reactive oxygen species), RNS(Reactive nitrogen species) can generated and those things effect to biological material. So we made simple plasma device using needle type of electrode and generated plasma. We used three kinds of gas and measured applied voltage and current. Also we observed optical emission spectrum. Using deuterium ramp, we can observed absorption spectrum and calculated radical density by lambert-beer's law. It is around ~1016cm3. And we can see the time-resolved absorption spectrum from monochromator, PMT(photo multiply tube), IV-converter, oscilloscope.

• 한국표면공학회지
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• 제54권6호
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• pp.340-347
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• 2021

Among various metal oxide semiconductors, ZnO has an excellent electrical, optical properties with a wide bandgap of 3.3 eV. It can be applied as a photocatalytic material due to its high absorption rate along with physical and chemical stability to UV light. In addition, it is important to control the morphology of ZnO because the size and shape of the ZnO make difference in physical properties. In this paper, we demonstrate synthesis of size-controlled ZnO tetrapods using an atmospheric pressure plasma system. A micro-sized Zn spherical powder was continuously introduced in the plume of the atmospheric plasma jet ignited with mixture of oxygen and nitrogen. The effect of plasma power and collection sites on ZnO nanostructure was investigated. After the plasma discharge for 10 min, the produced materials deposited inside the 60-cm-long quartz tube were obtained with respect to the distance from the plume. According to the SEM analysis, all the synthesized nanoparticles were found to be ZnO tetrapods ranging from 100 to 600-nm-diameter depending on both applied power and collection site. The photocatalytic efficiency was evaluated by color change of methylene blue solution using UV-Vis spectroscopy. The photocatalytic activity increased with the increase of (101) and (100) plane in ZnO tetrapods, which is caused by enhanced chemical effects of plasma process.

• 진공이야기
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• 제2권4호
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• pp.9-15
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• 2015

Nonthermal bio-compatible plasma (bioplasma) sources and their characteristics operating at atmospheric pressure could be used for biological cell interactions, especially for plasma bioscience and medicines. The electron temperatures and plasma densities of this bioplasma are measured to be 0.7 ~ 1.8 eV and $(3-5){\times}10^{14-15}cm^{-3}$, respectively. Herein, we introduced general schematic view of the plasma-initiated ultraviolet photolysis of water inside the biological solutions or living tissue for the essential generation mechanism of the reactive hydroxyl radical [OH] and hydrogen peroxide [$H_2O_2$], which may result in apoptotic cell death in plasma bioscience and medicines. Further, we surveyed the various nonthermal bioplasma sources including plasma jet, micro-DBD (dielectric barrier discharge) and nanosecond discharged plasma. The diseased biological protein, cancer, and mutated cells could be treated by these bioplasma sources or bioplasma activated water to result in their apoptosis for new paradigm of plasma bioscience and medicines.

• 한국진공학회지
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• 제22권5호
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• pp.238-244
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• 2013

태양전지 제조공정에서 열처리로 레이저를 사용하는 도핑공정은 태양전지의 성능을 결정짓는 중요한 요소이다. 그러나 퍼니스를 이용하는 공정에서는 선택적으로 고농도(Heavy) 도핑영역을 형성하기가 어렵다. 레이저를 사용한 선택적 도핑의 경우 고가의 레이저 장비가 요구되어지며, 레이저 도핑 후 고온의 에너지로 인한 웨이퍼의 구조적 손상 문제가 발생된다. 본 연구는 저가이면서 코로나 방전 구조의 대기압 플라즈마 소스를 제작하였고, 이를 통한 선택적 도핑에 관한 연구를 하였다. 대기압 플라즈마 제트는 Ar 가스를 주입하여 수십 kHz 주파수를 인가하여 플라즈마를 발생시키는 구조로 제작하였다. P-type 웨이퍼(Cz)에 인(P)이 shallow 도핑 된(120 Ohm/square) PSG (Phosphorus Silicate Glass)가 제거되지 않은 웨이퍼를 사용하였다. 대기압 플라즈마 도핑 공정 처리시간은 15 s와 30 s이며, 플라즈마 전류는 40 mA와 70 mA로 처리하였다. 웨이퍼의 도핑프로파일은 SIMS (Secondary Ion Mass Spectroscopy)측정을 통하여 분석하였으며, 도핑프로파일로 전기적 특성인 면저항(sheet resistance)을 파악하였다. 도펀트로 사용된 PSG에 대기압 플라즈마 제트로 도핑공정을 처리한 결과 전류와 플라즈마 처리시간이 증가됨에 따라 도핑깊이가 깊어지고, 면저항이 향상하였다. 대기압 플라즈마 도핑 후 웨이퍼의 표면구조 손상파악을 위한 SEM (Scanning Electron Microscopy) 측정결과 도핑 전과 후 웨이퍼의 표면구조는 차이가 없음을 확인하였으며, 대기압 플라즈마 도핑 폭도 전류와 플라즈마 처리시간이 증가됨에 따라 증가하였다.

• 한국치위생학회지
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• 제14권5호
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• pp.783-788
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• 2014

Objectives : The purpose of this study was to investigate the effect of non-thermal atmospheric pressure plasma jet(NTAPPJ) on surface properties and Streptococcus mutans disinfection of denture base resin. Methods : Self-cured denture base resin (Jet denture repair resin, Lang dental Mfg, co., USA) was used to make specimen($12mm{\times}2mm$). To observe surface change before and after plasma process, surface roughness and contact angle were measured. For sterilization experiments, the surfaces of specimens were treated with nitrogen and air NTAPPJ for 1 minute after S. mutans was inoculated on the material surfaces. Results : Before plasma process, surface roughness of denture base resin was $0.21{\mu}m{\pm}0.02{\mu}m$. After air and nitrogen NTAPPJ process, surface roughness was $0.19{\mu}m{\pm}0.03{\mu}m$ and $0.18{\mu}m{\pm}0.01{\mu}m$ respectively. There was no significant difference(p>0.05). Contact angle of control group without plasma process was $83.81^{\circ}{\pm}3.14^{\circ}$, while after plasma treatment, contact angles of air NTAPPJ and nitrogen NTAPPJ groups were $63.29^{\circ}{\pm}2.27^{\circ}$ and $46.68^{\circ}{\pm}5.82^{\circ}$ respectively. The result showed a significant decrease in contact angle after plasma process(p<0.05). Compared to the control group 6020.33(CFU/mL) without plasma process, CFU decreased significantly after air NTAPPJ 90.75(CFU/mL) and nitrogen NTAPPJ 80.25(CFU/mL) treatment(p<0.05). Conclusions : It was considered that NTAPPJ can be used for denture disinfection without changing surface properties of materials.

• 조명전기설비학회논문지
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• 제27권6호
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• pp.31-38
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• 2013

A pulse driven atmospheric plasma jet controlled by external ballast capacitor is developed. Unlike the most commonly use DBD sources, the proposed device utilizes bare metal electrode. The discharge energy per pulse can precisely be determined by changing voltage and capacitance of the ballast capacitor. It is shown that the device can provide wide range of plasma, from stable glow mode to near arc state. Current-voltage waveforms, optical emission spectra and discharge images are investigated as a function of an injection energy. The OES shows that He and oxygen lines are increased as a function of the external ballast capacitor. Ozone and rotational temperature have similar tendency with a power consumption. The feeding gas is He and the applied DC voltage is from 400V to 800V when the gap distance is $500{\mu}m$.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.230.2-230.2
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• 2016

A new approach for antimicrobial is based on the overproduction of reactive nitrogen species (RNS), especially; nitric oxide (NO) and peroxinitrite ($ONOO^-$-) are important factors to deactivate the bacteria. Recently, non-thermal atmospheric pressure plasma jet (APPJ) has been frequently used in the field of microbial sterilization through the generation of different kinds of RNS/ROS species. However, in previous study we showed APPJ has combine effects ROS/RNS on bacterial sterilization. It is not still clear whether this bacterial killing effect has been done through ROS or RNS. We need to further investigate separate effect of ROS and RNS on bacterial sterilization. Hence, in this work, we have enhanced NO production, especially; by applying a 1% of HNO3 vapour to the N2 based APPJ. In comparison with nitrogen plasma with inclusion of water vapour plasma, it has been shown that nitrogen plasma with inclusion of 1% of HNO3 vapour has higher efficiency in killing the E. coli and different type of cancer cell through the high production of NO. We also investigate the enhancement of NO species both in atmosphere by emission spectrum and inside the solution by ultraviolet absorption spectroscopy. Moreover, qPCR analysis of oxidative stress mRNA shows higher gene expression. It is noted that 1% of HNO3 vapour plasma generates high amount of NO for killing bacteria and cancer cell killing.

• 전기의세계
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• 제24권6호
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• pp.77-84
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• 1975

This paper treats A.C. arc movement in a transverse A.C. magnetic field at atmospheric pressure with the purpose of selecting electrode materials and obtaining detailed data for design of A.C. air circuit breaker, plasma accelerator and plasma jet. Arc velocities in transverse magnetic field are measured by varying arc current, arc voltage, gap length, magnetic flux density and the erosion of electrode surface, which influence arc velocities. The main results are; 1)Arc velocities in transverse magnetic field have different values according to electrodes of various materials and decrease in a descending order of cold cathode, medium cathode and hot cathode. 2)Arc velocities in transverse magnetic field increases with arc current, arc voltage, gap length and magnetic flux densith and on the other hand decrease with the increase of electrode surface erosion. 3)D.C.arc velocity in D.C. magnetic field is higher than A.C. arc velocity in A.C. magnetic field of the same value.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.206-206
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• 2016

플라즈마(plasma)란 전자와 이온이 분리된 제 4의 물질 상태이다. 이 연구의 핵심인 플라즈마 제트(plasma jet)로 재생과 출아를 하는 히드라(Hydra)를 처리하여 플라즈마가 히드라의 출아 정도에 어떠한 영향을 미치는지에 대해 연구를 진행하였다. 히드라는 자포동물문 히드로충강 히드로충목 히드라과 히드라속에 속하며 무척추동물이다. 몸의 길이는 약 5-15mm정도이며 촉수가 6-8개가 있다. 먹이 섭취는 촉수로 먹이를 마비시켜 입을 통해 먹는다. 히드라는 못이나 늪 등의 풀잎이나 물속에 떨어진 낙엽과 썩은 나뭇가지에 붙어 산다. 특히 히드라는 영양 상태의 좋고 나쁨에 따라 무성생식을 하거나 유성생식을 한다. 또한 약 1/200의 아주 작은 단위에서도 재생을 하는 특성을 가지고 있다. 이러한 히드라에 플라즈마 처리를 함으로써 플라즈마가 히드라의 출아 특성에 어떠한 영향을 미치는지에 대해 연구를 수행하였다. 실험에서 사용한 플라즈마 소스는 대기압 플라즈마 제트(Atmospheric pressure plasma jet)이며 Ar(아르곤) 가스를 이용하여 플라즈마를 발생시켰다. 플라즈마가 발생되면 생체용액과 반응을 하면서 ROS(reactive oxygen species)와 RNS(reactive nitrogen species)가 생성되는데 이 활성 종들이 플라즈마의 주요한 특성이라고 할 수 있다. ROS와 RNS에 의해서 세포가 사멸을 하거나 활성화되기도 한다. 또한, ROS와 RNS가 생체 시스템에 영향을 주는 것은 매우 잘 알려져 있다. 이 점을 이용하여 히드라를 1분, 5분, 10분 동안 플라즈마 처리하여 히드라의 출아 특성을 관찰하였다. 관찰한 결과 1분 처리한 히드라 Group과 5분 처리한 히드라 Group이 가장 개체 수 변화가 뛰어났고 10분 처리한 히드라Group은 오히려 개체 수가 감소하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2892-2897
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• 2008

Plasma techniques have been proposed to generate a hydrogen enrich gas to investigate a feasibility of plasma techniques on a fuel reforming, we considered a dry reforming and a partial oxidation with methane in the atmospheric pressure. For these experiments, we employed an arc jet plasma reactor. The effects of input power and oxidizer in each process were investigated by product analysis, including carbon monoxide, hydrogen, ethylene, propane, and acetylene as well as methane and carbon dioxide. In both processes, input electrical power activated the reactions significantly. The increased ratio of the carbon dioxide to methane in the dry reforming doesn't affect to a methane conversion, whereas increased ratio of oxidizer to methane in the partial oxidation was very effective for the reaction. Moreover, for a simultaneous treatment of methane and carbon dioxide, a feasibility of a dry reforming combined with partial oxidation also has been investigated.