• Corrosion Science and Technology
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• v.4 no.6
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• pp.222-225
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• 2005

The adhesion strength of metal plating on PC was studied. In this study, surface was treated by chemical agents or DBD(dielectric barrier discharge) plasma to imporve the adhesion. The surface roughness, contact angle, gloss of plating and adhesive strength were measured. Adhesion strengths of Ni plating on prepared PC by NaOH and KOH solution were $12.3kgf/cm^2$ and $7.5kgf/cm^2$, respectively. The highest adhesion strength was obtained in the plasma treated one, $27.8kgf/cm^2$.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.171-171
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• 2011

Atmospheric pressure- plasma enhanced chemical vapor deposition(AP-PECVD)Processes are recognized as promising and cost effective methods for wide-area coating on sheets of steel, glass, polymeric web, etc. In this study, $SiO_xC_y$ thin films were deposited by using AP-PECVD with a dielectric barrier discharge(DBD). The characteristic of $SiO_xC_y$ thin films were investigated as afunction of the HMDSO/O2/He flow rate. And the moisture permeability of $SiO_xC_y$ thin films was studied. The $SiO_xC_y$ thin films were characterized by the Fourier-transformed Infrared(FT-IR) spectroscopy and also investigated by X-ray photo electron spectroscopy(XPS), Auger Electron Spectroscopy(AES). The moisture permeability of $SiO_xC_y$ thin films was investigated by $H_2O$ permeability tester Detailed experimental results will be demonstrated through th present work.

• Food Science and Preservation
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• v.24 no.3
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• pp.483-489
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• 2017

Phloridzin is a predominant member of the chemical class of dihydrochalcones and mainly found in apple. The biological activity of phloridzin treated with dielectric barrier discharge (DBD) plasma was evaluated to investigate whether exposure to plasma can be used as a tools to enhance the biological activity of natural resources. DBD plasma treatment of phloridzin was carried out for three different exposure times. The antioxidant effects of degraded phloridzin for different reaction time were evaluated via radical scavenging assay using DPPH radical. In addition, the anti-diabetic and anti-obesity properties of the degraded phloridzin were measured based on ${\alpha}$-glucosidase and pancreatic lipase inhibitory activities. Phloridzin treated for 60 min showed significantly higher radical scavenging, ${\alpha}$-glucosidase and pancreatic lipase inhibitory activities compared to the tested positive controls. Degradation of phloridizin induced by DBD plasma might be responsible for enhancing the biological activity of phloridizin.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1352-1353
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• 2008

In this study, aluminium - doped zinc oxide (ZnO:Al) transparent conducting film was deposited on PET(polyethylen terephthalate) substrate by r.f. magnetron sputtering method. PET substrate was surface-treated in an atmospheric pressure DBD(dielectric barrier discharge) plasma to increase deposition rate and to improve electrical propesties. Morphological changes by DBD plasma were obsered using contact angle measurement. The contact angle of water on PET was reduced from 62$^{\circ}$ to 42$^{\circ}$ by DBD plasma surface treatment. The plasma treatment also increased deposition rate and electrical propesties. The electrical resistivity as low as $4.97{\times}10^{-3}[{\Omega}-cm]$ and the deposition rate of 234[${\AA}$-m/min] were obtained in ZnO:Al film with surface treatment time of 5min, and 20min., respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.552-552
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• 2013

In our study we consider Al2O3 ceramic substrates for Plasma Surface Treatments in order to improve deposited diamond surface and increase diamond deposition rate by applying DBD (Dielectric Barrier Dischrge) system. Because Plasma Surface Treatments was used as a modification method of material surface properties like surface free energy, wettability, and adhesion. By applying Plasma Surface Treatments diamond films are deposited on the Al2O3 ceramic substrates. DC Arc Plasmatron with mathane and hydrogen gases is used. Deposited diamond films are investigated by SEM (Scanning Electron Microscopy), AFM (Atomic Force Microscopy) and XRD (X-ray Diffractometer). Then the C-H stretching of synthetic diamond films by FTIR (Fourier Transform Infrared Spectroscopy) is studied. As a result, nanocrystalline diamond films were identified by using SEM and diamond properties in XRD peaks at (111, $43.8{\Box}$, (220, $75.3{\Box}$ and (311, $90.4{\Box}$ were shown. Absorption peaks in FTIR spectrum, caused by CHx sp3 bond stretching of CVD diamond films, were identified as well. Finally, we improved such parameters as depostion rate ($2.3{\mu}m$/h), diamond surface uniformity, and impurities level by applying Plasma Surface Treatments. These experimental results show the importance of Plasma Surface Treatments for diamond deposition by a plasma source.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.459-466
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• 2012

In order to improved treatment performance of dielectric barrier discharge (DBD) plasma, plasm + UV process and gas-liquid mixing method has been investigated. This study investigated the degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical). The basic DBD plasma reactor of this study consisted of a plasma reactor (consist of quartz dielectric tube, titanium discharge (inner) and ground (outer) electrode), air and power supply system. Improvement of plasma reactor was done by the combined basic plasma reactor with the UV process, adapt of gas-liquid mixer. The effect of UV power of plasma + UV process (0~10 W), gas-liquid mixing existence and type of mixer, air flow rate (1~6 L/min), range of diffuser pore size (16~$160{\mu}m$), water circulation rate (2.8~9.4 L/min) and UV power of improved plasma + UV process (0~10 W) were evaluated. The experimental results showed that RNO degradation of optimum plasma + UV process was 7.36% higher than that of the basic plasma reactor. It was observed that the RNO decomposition of gas-liquid mixing method was higher than that of the plasma + UV process. Performance for RNO degradation with gas-liquid mixing method lie in: gas-liquid mixing type > pump type > basic reactor. RNO degradation of improved reactor which is adapted gas-liquid mixer of diffuser type showed increase of 17.42% removal efficiency. The optimum air flow rate, range of diffuser pore size and water circulation rate for the RNO degradation at improved reactor system were 4 L/min, 40~$100{\mu}m$ and 6.9 L/min, respectively. Synergistic effect of gas-liquid mixing plasma + UV process was found to be insignificant.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1627-1634
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• 2014

Odor control technology include absorption, adsorption, incineration and biological treatments. But, most of processes have some problems such as secondary organic acids discharge at the final odor treatment facility. In order to solve the problems for effective treatment of organic acids in odor, it is necessary to develop a new type advanced odor control technology. Some of the technology are plasma only process and plasma hybrid process as key process of the advanced technology. In this study, odor removal performance was compared DBD(Dielectric Barrier Discharge)plasma process with PCHP(plasma catalysis hybrid process) by gaseous ammonia, formaldehyde and acetic acid. Plasma only process by acetic acid obtained higher treatment efficiency above 90%, and PCHP reached its efficiency up to 96%. Acetic acid is relatively easy pollutant to control its concentration other than sulfur and nitrogen odor compounds, because it has tendency to react with water quickly. To test of the performance of DBD plasma process by applied voltage, the tests were conducted to find the dependence of experimental conditions of the applied voltage at 13 kV and 15 kV separately. With an applied voltage at 15 kV, the treatment efficiency was achieved to more higher than 13 kV from 83% to 99% on ammonia, formaldehyde and acetic acid. It seems to the odor treatment efficiency depends on the applied voltage, temperature, humidity and chemical bonding of odors.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.553-553
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• 2013

상압 플라즈마 기술은 표면처리, 온존 발생장치, VOC (Volatile Organic compound) 제거등 다양한 산업분야에서 응용되고 있다. 상압플라즈마 기술 또한 DBD (Dielectric barrier discharge), Griding Arc, SDIP (Surface Discharge Induced Plasma) 등 다양한 기술들이 개발되어져 왔다. VOC를 제거하기 위한 다양한 플라즈마 기술중 특히 BDB 방법과 SDIP 기술들은 플라즈마에 의한 VOC 분해 뿐만 아니라 오존 발생을 통하여 VOC성분을 분해하는 것으로 알려져 있으며 효율이 매우 뛰어난 것으로 보고 되고 있다. 그러나 BDB 방전의 경우 방전이 발생하는 간격이 매우 작아 공기를 정화시키기 위해 좁은 유로를 통하여 일정넓이를 이동하여하 하기 때문에 압력감소가 심하며 이를 개선하기위해 다단으로 설계할 경우 구조가 복잡하고 가격이 고가인 단점이 있다. 본 연구에서는 두 개의 면 전극이 마주보는 형태로 된 DBD 구조의 단점을 보완하기 위하여 빗살무늬 모양의 다층구조의 선형전극으로 구조를 변화시켜 전극에 의한 압력감소를 방지하고 효율적으로 플라즈마 및 오존을 발생시킬 수 있는 VOC제거용 상압 플라즈마 발생장치를 개발하였다. 또한 플라즈마 발생 및 오존발생량이 우수한 것으로 알려져 있는 SDIP 장치 또한 제작하여 비교 평가를 하였다. 제작된 플라즈마 발생장치는 60 Hz와 20kHz의 교류 고압파워 서플라이를 이용하여 플라즈마 발생실험을 진행하였다. 선행 연구에서는 60 Hz의 고압 파워 서플라이를 이용하여도 플라즈마 방전이 잘 된다고 보고되었는데 본 실험에서 60 Hz 파워 서플라이를 사용할 경우 15 kV 이상이 인가될 때 아주 약하게 오존이 발생하는 현상이 관찰되었으나 육안으로 구분이 될 만큼의 플라즈마 방전은 발생하지 않았다. 20kHz의 고압파워 서플라이를 사용한 경우에는 비교적 낮은 전압인 7 kV에서 방전이 관찰되었으며 분당 22 mg의 오존이 발생하였다. SDIP를 이용한 경우 플라즈마가 발생하는 조건은 SDIP의 기하학적 형상에 많이 의존하게 된다. 본 실험에 SDIP 장치는 매우 낮은 전압에서 방전을 시작하였다. 기존의 DBD와는 다르게 1.7 kV에서 플라즈마 발생하였으며 1.8 kV에서 정상적인 플라즈마 방전이 발생하였다. 이때 분당 3.1 mg의 오존이 발생하였다. 오존 발생양은 앞에 빗살형 플라즈마 방전장치에 비하여 낮은데 인가되는 전력을 고려하면 입력된 전기 에너지당 오존발생양은 비슷한 수준이였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.209.1-209.1
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• 2016

우리에게 잘 알려져 있지 않은 강장동물 히드라는 뛰어난 세포 분열 능력을 가지고 있다. 출아(무성생식)를 하면서도 환경에 따라 유성생식을 하기도 하는 몇 안 되는 생물 중 하나인 히드라는 재생능력이 강하여 몸의 200분의 1만 잘려도 재생을 할 수 있는 능력을 가지고 있다. 이러한 히드라의 재생능력을 높은 에너지인 플라즈마에 노출시켜 보았다. 플라즈마는 열, 빛, 화학 활성종, 이온, 전자를 발생하며 이 중 열 및 화학적 자극을 중심으로 관찰하였다. 생물이 수용할 수 있는 열에너지를 넘게 받는다면 그 성질이 변하는 점을 이용해 액체 방전소스를 이용하여 플라즈마의 열적인 효과를 주었고, DBD소스로는 약 염기를 띠는 라디칼(활성종)용액을 배양액으로 만들어 히드라에게 배양시켜 히드라의 생장능력 변화를 알아보았다. 생장능력의 변화는 히드라의 개체 수를 통해 관찰하였다. 플라즈마를 발생시키는 소스는 다양하며 그 중 이번 실험에서는 액체 방전 소스와 DBD를 이용하였다. 액체방전 소스는 누전을 막기 위해 세라믹 관에 금속선을 넣어 고전압을 인가하여 방전하였고, DBD(Dielectric Barrier Discharge의 약어)는 유전체 장벽을 이용하여 기체를 방전시키는 방식이다. DBD는 주로 살균 용도로 연구 중이며, DBD는 주변 기체들을 반응시켜 라디칼을 상당히 만들어 낼 수가 있다. 한편, 생물학에서 주목 받고 있는 히드라는 200분의 1만 잘려도 재생이 되는 재생능력을 갖고 있다. 히드라의 이러한 생장 및 재생속도는 생체모방 기술로도 주목을 받고 있다. 이번 실험은 최근 연구되고 있는 플라즈마의 효과를 히드라에 적용한 것으로 플라즈마의 간접적인 영향이 히드라에 어떠한 영향을 줄 것인지 알아보았다. 간접적인 영향으로는 크게 열적인 요인과 화학적인 요인으로 나누어 관찰하였다. 실험을 통해 히드라의 변화를 알아보고 그 결과가 실용가능한지를 알아보고자 한다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.5
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• pp.44-51
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• 2008

UV lamp systems have been used for cleaning of display panels of TFT LCD or Plasma Display Panel (PDP). However, the needs for high efficient cleaning and low cost made high voltage plasma cleaning techniques to be developed and to be improved. Dielectric-Barrier Discharges (DBDs), also referred to as barrier discharges or silent discharges have been exclusively related to ozone generation for a long time. In this paper, a 6kW high voltage plasma power supply system was developed for LCD cleaning. The 3-phase input voltage is rectified and then inverter system is used to make a high frequency pulse train, which is rectified after passing through a high-power transformer. Finally, hi-directional high voltage pulse switching circuits are used to generate the high voltage plasma. Some experimental results showed the usefulness of atmospheric plasma for LCD panel cleaning.