• 환경생물
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• 제40권4호
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• pp.641-650
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• 2022

본 연구의 목적은 양식장 배출수 내에 포함된 5종의 항생제(tetracycline, doxycycline, oxytetracycline, clindamycin 및 erythromycin)를 제거하기 위해 사용한 수중 비열 유전체장벽 방전 플라즈마(Dielectric Barrier Discharge plasma, DBD plasma) 장치 안으로 공기와 산소를 각각 주입했을 때 항생제의 제거효율을 비교하는 것이다. DBD plasma를 발생시키기 위해서 주어진 전압은 27.8 kV이었고, 처리간격은 0, 0.5, 1, 2, 4, 8, 16 및 32분이었다. 3종의 tetracycline계 항생제는 공기를 주입했을 때는 4분만에 유의하게 감소하였고, 산소를 주입했을 때는 30초만에 유의성을 나타내었다. 32분째 공기와 산소를 각각 주입한 결과, tetracycline은 78.1%와 95.8%, doxycycline은 77.1%와 96.3% 그리고 oxytetracycline은 77.1%와 95.5% 감소하였다. Clindamycin은 공기를 주입했을 때 59.6%가 감소되었고, 산소는 83.0% 감소되었다. 또한, erythromycin은 공기주입 시 53.3%가 감소되었고 산소 주입 시 74.3%가 감소하여 두 항생제 모두 tetracycline계 항생제보다 낮은 제거 효율을 보였다. 결론적으로 수중 DBD plasma는 양식장 배출수 내에 포함된 5종의 항생제를 감소시킬 수 있고, 제거 효율은 공기보다 산소를 주입하는 것이 더 효과적이다.

• 한국염색가공학회지
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• 제27권1호
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• pp.18-26
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• 2015

para-aramid fibers were treated by atmosphere air plasma to improve the interfacial adhesion. The wettability of plasma-treated aramid fiber was observed by means of dynamic contact angle surface free energy measurement. Surface roughness were investigated with the help of scanning electron microscopy and atomic force microscopy. The tensile test of aramid fiber roving was carried out to determine the effect of plasma surface treatments on the mechanical properties of the fibers. A pull-out force test was carried out to observe the interfacial adhesion effect with matrix material. It was found that surface modification and a chemical component ratio of the aramid fibers improved wettability and adhesion characterization. After oxygen plasma, it was indicated that modified the surface roughness of aramid fiber increased mechanical interlocking between the fiber surface and vinylester resin. Consequently the oxygen plasma treatment is able to improve fiber-matrix adhesion through excited functional group and etching effect on fiber surface.

• 융합정보논문지
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• 제11권6호
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• pp.146-153
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• 2021

최근 페로브스카이트 반도체 물질에 대한 연구가 이루어지고 있고, 이 물질에 대한 표면 처리를 이용한 특성 평가는 후속 연구들의 기반이 된다. 따라서, 본 논문에서는 상압분위기에서 플라즈마가 형성되는 상압플라즈마 장비로 산소 플라즈마를 생성하여 공기중에 약 6개월정도 노출시킨 페로브스카이트 박막을 표면 처리한 결과에 대해 연구하였다. 6개월간 노출시킨 이유는 페로브스카이트 박막은 유기물과 무기물로 이루어져 있기 때문에 공기 중에 노출되면, 산소나 수증기와의 반응을 통해 표면이 변화된다. 따라서, 이러한 변화를 원래 막으로의 복원이 가능한지 알아보기 위함이다. 산소플라즈마 분위기에서 1초부터 1200초까지 공정 시간을 변화시켜 가면서 표면 형상과 원소들 비율을 분석하였다. 이러한 결과는 페로브스카이트 막이 시간에 따라 변화가 일어나더라도 플라즈마 처리를 통해 이를 해결하는 방안을 제공한다.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.983-989
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• 2012

The purpose of this paper is to decide the optimum synthesis conditions of polycrystalline diamond films according to the ratio of gas mixture. Diamond films were deposited with cyclo-hexane as a carbon precursor by the microwave plasma enhanced chemical vapor deposition process. The optimum oxygen ratio to cyclo-hexane was reached about 125 % under the fixed 0.3% c-hexane in hydrogen. Oxygen plays a role in etching the graphitic components of carbon sp2 bond effectively. By OES measurement, the best synthesis conditions found out about 12.5 % and 15.75 %, which is the emission intensity ratios of CH(B-X) and $H{\beta}$ on $H{\alpha}$, respectively. Also, the electron temperature was similar about 5,000 to 5,200 K in this work.

• 한국전기전자재료학회논문지
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• 제11권5호
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• pp.340-346
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• 1998

In this study, we intended to investigate aging effect of polyimide prepared by VDPD(vapor deposition polymerized method). The prepared polymide was treated by the oxygen and argon gas plasma. And we evaluated the polyimide treated by plasma from contact angle, surface leakage current, FT-IR and SEM. We know that the structure of polyimide at surface are changed to amide structure by plasma treating. It seems that strong energy of plasma causes breaking the molecular chin of the polyimide. And surface roughness increases with plasma treating time increased and sequentially the wettability and leakage current increases.

• 한국표면공학회지
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• 제40권3호
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• pp.144-148
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• 2007

To prepare the transparent electrode for electronic devices such as flat panel or flexible displays, solar cells, and touch panels; tin doped $In_2O_3$ (ITO) films with low resistivity and a high transparency were fabricated using a facing target sputtering (FTS) system at the various oxygen gas flow rate. The carrier concentration and mobility of ITO films were measured by Hall Effect measurement. And the transmittance was measured using the UV-VIS spectrometer. As a result, we can obtain the ITO thin films prepared at 10% oxygen gas flow ratio, thickness 150 nm with transmittance 85% and resistivity $8.1{\times}10^{-4}{\Omega}cm$ and surface roughness 5.01 nm.

• 공업화학
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• 제25권4호
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• pp.386-391
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• 2014

본 연구에서는 상압 저온 코로나 방전 플라즈마를 화산암재(스코리아) 분말의 살균에 적용하였다. 스코리아 분말에 Escherichia coli (E. coli) 배양액을 살포하여 균일하게 혼합한 후, 코로나 방전 플라즈마 특성 인자인 방전전력, 방전시간, 주입기체, 전극간격 등의 조건을 변화시키며 E. coli 살균효율을 조사하였다. 실험 결과 상압 저온 코로나 방전 플라즈마는 분말상의 스코리아 살균에 아주 효과적인 것으로 나타났으며, 방전전력 15 W에서 5 min 동안 살균한 결과 E. coli가 99.9% 이상 사멸하였다. 방전전력, 방전시간, 인가전압이 증가할수록 사멸율이 향상되었다. 반응기에 주입되는 기체의 종류에 따른 살균력 실험 결과, 산소 > 모사공기(산소 20%) > 질소 순으로 나타났다. 코로나 방전 플라즈마에 의한 E. coli 살균은 자외선과 활성산화종(산소라디칼, OH라디칼, 오존 등)에 의한 세포막 침식 및 에칭, 그리고 플라즈마 방전 스트리머에 의한 대장균 세포막 파괴로 설명할 수 있다.

• Fibers and Polymers
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• 제4권4호
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• pp.145-150
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• 2003

Polypropylene nonwoven fabrics were exposed to He/$O_2$ atmospheric pressure glow discharge plasma. Surface chemical analysis and contact angle measurement revealed the surface oxidation by formation of new functional groups after plasma treatment. Weight loss (%) measurement and scanning electron microscopy analysis showed a significant plasma etching effect. It was investigated in low-stress mechanical properties of the fabrics using Kawabata Evaluation System (KES-FB). The surface morphology change by plasma treatment increased surface friction due to an enhancement of fiber-to-fiber friction, resulting in change of other low-stress mechanical properties of fabric.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.608-611
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• 2000

Large area plasma source becomes important as the substrate size increases. In this work, four inductively coupled plasma(ICP) unit sources are distributed 2${\times}$2 array. E-ICP concept is applied to the 2${\times}$2 array ICP and its effect is examined. Characteristics of the plasma are measured, and photoresist etching is performed with oxygen plasma. Good etching characteristic in terms of etching rate and uniformity can be obtained with E-ICP.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.68.1-68.1
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• 2012

The best part of graphene is - charge-carriers in it are mass less particles which move in near relativistic speeds. Comparing to other materials, electrons in graphene travel much faster - at speeds of $10^8cm/s$. A graphene sheet is pure enough to ensure that electrons can travel a fair distance before colliding. Electronic devices few nanometers long that would be able to transmit charge at breath taking speeds for a fraction of power compared to present day CMOS transistors. Many researches try to check a possibility to make it a perfect replacement for silicon based devices. Graphene has shown high potential to be used as interconnects in the field of high frequency electrical devices. With all those advantages of graphene, we demonstrate characteristics of electrical and optical properties of graphene such as the effect of graphene geometry on the microwave properties using the measurements of S-parameter in range of 500 MHz - 40 GHz at room temperature condition. We confirm that impedance and resistance decrease with increasing the number of graphene layer and w/L ratio. This result shows proper geometry of graphene to be used as high frequency interconnects. This study also presents the optical properties of graphene oxide (GO), which were deposited in different substrate, or influenced by oxygen plasma, were confirmed using different characterization techniques. 4-6 layers of the polycrystalline GO layers, which were confirmed by High resolution transmission electron microscopy (HRTEM) and electron diffraction analysis, were shown short range order of crystallization by the substrate as well as interlayer effect with an increase in interplanar spacing, which can be attributed to the presence of oxygen functional groups on its layers. X-ray photoelectron Spectroscopy (XPS) and Raman spectroscopy confirms the presence of the $sp^2$ and $sp^3$ hybridization due to the disordered crystal structures of the carbon atoms results from oxidation, and Fourier Transform Infrared spectroscopy (FTIR) and XPS analysis shows the changes in oxygen functional groups with nature of substrate. Moreover, the photoluminescent (PL) peak emission wavelength varies with substrate and the broad energy level distribution produces excitation dependent PL emission in a broad wavelength ranging from 400 to 650 nm. The structural and optical properties of oxygen plasma treated GO films for possible optoelectronic applications were also investigated using various characterization techniques. HRTEM and electron diffraction analysis confirmed that the oxygen plasma treatment results short range order crystallization in GO films with an increase in interplanar spacing, which can be attributed to the presence of oxygen functional groups. In addition, Electron energy loss spectroscopy (EELS) and Raman spectroscopy confirms the presence of the $sp^2$ and $sp^3$ hybridization due to the disordered crystal structures of the carbon atoms results from oxidation and XPS analysis shows that epoxy pairs convert to more stable C=O and O-C=O groups with oxygen plasma treatment. The broad energy level distribution resulting from the broad size distribution of the $sp^2$ clusters produces excitation dependent PL emission in a broad wavelength range from 400 to 650 nm. Our results suggest that substrate influenced, or oxygen treatment GO has higher potential for future optoelectronic devices by its various optical properties and visible PL emission.