• 분석과학
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• 제15권2호
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• pp.108-114
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• 2002

고체 시료를 직접 분석하기 위하여 글로우 방전 원자 방출법을 이용한 새로운 장치를 개발하였다. 이 시스템은 기존의 gas-jet boosted nozzle을 개선한 새로운 방전 셀과 Radio-frequency 전원장치를 사용하였다. 기존의 gas-jet boosted nozzle의 경우 재침전이 적고, 시료 손실량이 많아서 낮은 방전 전력에서 저 합금강의 미량 분석에 적합하였다. 하지만 높은 방전 전력을 사용할 경우 시료 손실량이 많아지고, 재석출(redeposition)이 증가함으로 해서 플라스마가 불안정해지는 단점을 지니고 있었다. 기존의 글로우 방전 셀의 경우 방전 전력을 높일 수록 플라스마의 들뜸 온도가 증가하는 경향을 가진다. 이 때문에 높은 방전 전력에서는 플라스마의 온도가 높아져서 극미량 분석이 가능할 수 있지만, 기존의 노즐 부분에 문제점으로 인해 높은 방전 전력으로 분석하기에는 부적합하였다. 이러한 문제점을 modified gas-jet boosted nozzle은 시료 손실량이 같은 방전 전력에서 기존의 가스 제트 흐름노즐에 비하여 감소하지만 높은 방전 전력에서는 플라스마 안정도가 증가하여 극미량 분석이 가능하도록 개선하였다. 본 시스템은 여러 가지 방전에 미치는 실험 변수인 압력과 가스 흐름량 그리고 방전 전력의 변화에 따른 시료 손실 속도와 방출 세기 등의 변화를 측정하여 최적화 하였으며, 표준 시료 Fe합금을 이용하여서 미량 분석을 하였다.

• 한국응용곤충학회지
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• 제51권3호
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• pp.255-263
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• 2012

고주파 처리는 파밤나방(Spodoptera exigua)의 생리변화를 유발시켜 섭식행동, 발육 및 면역반응의 변화를 초래한다. 본 연구는 이러한 고주파의 영향을 파밤나방의 생화학적 변화를 통해 분석했다. 고주파(5,000 Hz, 95 dB) 처리는 중장 상피세포의 단백질 합성과 분비를 억제시켰다. 또한 이 고주파 처리는 중장의 인지질분해(phospholipase $A_2$) 소화효소의 활성을 현격하게 억제시켰다. 고주파 처리는 세 종류의 열충격단백질과 지질운송단백질(apolipophorin III)의 유전자 발현을 변동시켰고 이러한 변화는 중장 조직에서 뚜렷했다. 혈림프 혈장에 존재하는 지질 및 유리당의 함량이 고주파 처리에 의해 현격하게 증가했다. 이러한 결과는 고주파 처리가 파밤나방의 체내 생화학적 변화를 유발시켜 생리적 교란을 유도하는 스트레스로 작용한다는 것을 제시하고 있다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.904-907
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• 2002

In this study, the plasma-assisted $CO_2$ conversion characteristics were investigated in the streamer corona discharge and silent discharge reactors with dielectric of $Al_2O_3$, to improve the conversion efficiency $CO_2$. Some discharge characteristics of $CO_2$ as parameters of gap spacing and applied voltage frequency, in both corona and silent discharge reactor were also obtained. The maximum $CO_2$ conversion rate was 10.1 [%] under the 5.2 [W] of discharge power and 250 [Hz] of applied voltage frequency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.122-124
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• 2005

The flat panel lamp is used as back light. It is perceived the best type for the wide size LCD of back light system. However, the flat panel lamp has high value of heat. So it need to improve efficiency. Therefore, more researches are requested for the back light of the flat panel lamp. In this paper, the properties of spectrum is investigated according to change in frequency from 30kHz to 60kHz using power supplies voltage with changing from 500V to 700V. As a result, main spectrum peak of plasma showed in 450[nm], 630[nm], 750[nm] and spectrum peak of 750nm is the highest.

• Journal of Magnetics
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• 제18권2호
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• pp.163-167
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• 2013

We fabricated prototype cantilevers for mechanically detected high-frequency ESR measurement. Cantilevers are fabricated from silicon-on-insulator (SOI) wafers using standard MEMS techniques such as lithography, wet etching, and plasma etching. Using commercial SOI wafers, fabrication cost and the number of processes can be substantially reduced. In this study, three types of cantilevers, designed for capacitive and optical detection, are shown. Capacitive type with lateral dimensions of $3.5{\times}1.6mm^2$ is aimed for low spin concentration sample. On the other hand, optical detection type with lateral dimensions of $50{\times}200{\mu}m^2$ is developed for high-sensitive detection of tiny samples such as newly synthesized microcrystals.

• E2M - 전기 전자와 첨단 소재
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• 제10권8호
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• pp.807-811
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• 1997

In this paper we have investigated the removal characteristics of NOx by pulsed corona discharge with a multi-pointplane electrode where a magnetic field is applied in the discharge region. The efficiency of NOx removal was measured and analyzed as a function of pulse frequency gas flow rate NOx initial concentration magnetic flux density. In this result the highest removal efficiency of NOx was obtained at the following operating conditions; the frequency =400[Hz] gas flow =1[$\ell$/min] initial concentration= 400[ppm] and magnetic flux density=0.36[T].

• 한국전기전자재료학회논문지
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• 제14권8호
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• pp.622-628
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• 2001

We developed 1- and 2-dimensional fluid model for the analysis of a capacitively coupled Ar RF(Radio Frequency) glow discharge. This discharge is in pure Ar gas at the pressure 100[mTorr], frequency 13.56[MHz] and voltage amplitude 120[V}. This model is based on the equations of continuity and electron energy conservation coupled with Poison equation. 2-dimensional model is simulated on the condition of GEC(Gaseous Electronic Conference cell). The geometry of the discharge chamber and the electrodes used in the model is cylindrically simmetric; tow cylinders for the electrodes are surrounded by the grounded chamber. It is shown that 1-dimensional model is very useful on the understanding of RF glow discharge property and of the movement of charged particles. 2-dimensional model predicts off-axis maximum structure as in the experiments and has the results in qualitatively and quantitatively good agreement with the experiments. Effects of dc self-bias voltage, guard ring and reactor geometry is discussed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.290-290
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• 2011

In this study Diamond-like carbon (DLC) films were deposited on p-type Si substrates using a Radio-Frequency magnetron Sputtering system. The DLC film was deposited by bombarding graphite target with a N2/Ar plasma mixture with various conditions: substrate, pressure, deposition time, temperature of substrate, power and ratio of gas mixture. The effect on the conduction and hardness of DLC thin films were investigated. The conduction of DLC films were measured by I-V measurement. In addition, Raman analysis was performed to study the chemical bonding structure. The hardness was measured by Nano indentation. Atomic Force Microscopy was used for determined surface morphology of DLC film.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.224-227
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• 2007

The reconstruction characteristics of MgO (111) textured protective layer by over-frequency accelerated discharge in AC-PDP were investigated and correlated to the variations of electronic structures. The reconstruction process and exaggerated grain growth (EGG) were explained by defect-assisted 2-D nucleation and growth mechanism combined with charged cluster model.

• 한국세라믹학회지
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• 제48권5호
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• pp.342-347
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• 2011

Nanocrystalline TiN films were deposited on Si(100) substrate using asymmetric pulsed DC reactive magnetron sputtering. We investigated the growing behavior and the structural properties of TiN films with change of duty cycle and pulsed frequency. Grain size of TiN films were decreased from 87.2 nm to 9.8 nm with decrease of duty cycle. The $2{\theta}$ values for (111) and (200) crystallographic planes of the TiN films were also decreased with decrease of duty cycle. This shift in $2{\theta}$ could be attributed to compressive stress in the TiN coatings. Thus, the change of plasma parameter has a strong influence not only on the microstructure but also on the residual stresses of TiN films.