• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.149-149
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• 1999

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 1998년도 추계학술발표회 초록집
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• pp.79-80
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• 1998

• 한국광학회지
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• 제12권2호
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• pp.115-120
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• 2001

본 연구는 고온 고압의 전열(electrothermal)플라즈마내에 존재하는 구리원자의 발광 스펙트럼을 정량적으로 분석하는 방법에 대해 논하였다. 플라즈마는 플라즈마 발생장치내에 설치되어 있는 모세관 양단의 두 개의 전극이 방전함으로써 발생하며 고속으로 대기를 향해 전파해 나간다. 플라즈마의 특성을 분석하기 위해서는 플라즈마의 여기온도나 전자밀도와 같은 물리량의 측정이 필요하다. 그러나 여기온도나 전자밀동와 직접적으로 관련이 있는 발광 스펙트럼은 분광시스템의 파장에 따른 서로다른 응답 특성 때문에 왜곡되어질 수 있다 따라서 본 연구에서는 펄스 플라즈마 제트로부터 얻은 구리원자의 발광 스펙트럼을 정밀하게 보정하는 방법을 제시하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권10호
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• pp.710-715
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• 1999

The purpose of this work is to develop a high-efficiency air cleaning system for air pollutants such as particulate and gaseous state in indoor environments. In order to enhance a removal efficiency of gaseous state pollutants, we suggested that pulsed discharge plasma be combined with $TiO_2$ photocatalyst (photocatalytic plasma air cleaning unit). We investigated experimentally the basic characteristics of photocatalytic plasma air cleaning unit and measured air pollutants removal efficiency. The wavelength of light radiated from pulsed discharge plasma under the atmospheric condition was 310~380nm. Its energy is enough to excite the $TiO_2$ photocatalyst and it makes a photochemical reaction in the surface of $TiO_2$ photocatalyst. The removal quantity of trimethylamine$((CH_3)_3N)\; was\; 130mg/m^34 which is twice quantity of pulsed discharge plasma without $TiO_2$ phtocatalyst unit. From the result of gas analysis using FT-IR, nitric oxide was not detected and trimethylamine was decomposed to $H_2O\; and \;CO_2$. And trimethylamine removal efficiency was 95%. These experimental results indicate that photocatalytic plasma air cleaning unit is a potential method in removing the pollutants.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.119.1-119.1
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• 2014

Toxic waste disposal: Many people think that when toxic waste is dumped into the ocean or into the air, it disappears. This belief is incorrect. Rather than disappearing, it accumulates over time and slowly destroys the environment. Ultimately, it leads to the destruction of human race. Plasma is environmentally friendly: Plasma is environmentally friendly because it is created and disappears. When plasma is formed on the earth, you need certain conditions such as accelerating electrons by an electrical discharge or a particle accelerator. When this is gone, plasma completely disappears, leaving no impact on the environment. Plasmas produce radicals: Even if plasma density is low at atmospheric pressure, many radicals (excited states of molecules) are created. These radicals are chemically very aggressive. So instead of using harmful chemicals, plasma can be utilized for less of an impact on the environment. Plasma can reach very high temperatures: Plasma is also useful because when you control the density, you can easily reach high temperatures up to $5000{\sim}6000^{\circ}C$ at atmosphere pressure. Because of this heat and the chemical aggressiveness of the plasma, there are many green applications for plasma technology. Pulsed power technology: Pulsed electric field for extraction, drying and killing bacteria. Treatment of biological tissue by pulsed electric fields: Extraction of substances from cells: Sterilisation, Medical applications, Growth stimulation, Food preparation. Each application has its specialities, especially with respect to pulse shape and electric field strength.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.176.2-176.2
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• 2013

Property of optical diagnostics for pulse-discharged plasma in liquid and its biological applications to proteins are investigated by making use of high voltage Marx generator. The Marx generator has been consisted of 5 stages, where each charging capacitor is 0.5 ${\mu}F$, to generate a high voltage pulse with rising time of $1{\mu}s$. We have applied an input voltage of 6 kV to the each capacitor of 0.5 ${\mu}F$. High voltage pulsed plasma has been generated inside a polycarbonate tube by a single-shot operation, where the breakdown voltage is measured to be 7 kV, current of 1.2 kA, and pulse width of ~ 1 ${\mu}s$ between the two electrodes of anode-cathode whose material is made of tungsten pin, which are immersed into the liquids. We have investigated the emitted hydrogen lines for optical diagnostics of high voltage pulsed plasma. The emission line of 656.3 nm from $H-{\alpha}$ and 486.1 nm from $H-{\beta}$ have been measured by a monochromator. If we assumed that the focused plasma regions satisfy the local thermodynamic equilibrium conditions, the electron temperature and density of the high voltage pulsed plasma in liquid could be obtained by the Stark broadening of optical emission spectroscopy. For the investigation of the influence of pulsed plasma on biological proteins, we have exposed it onto the proteins such as hemoglobin and myoglobin. The structural changes in these proteins and their analysis have also been obtained by circular dichroism (CD) and ultraviolet (UV) visible spectroscopy.

• Journal of Welding and Joining
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• 제19권4호
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• pp.375-378
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• 2001

The new development of the surface hardening technology has been attracted to machine designer and materials scientist in the view point of improvement in the lifetime and performance of the machine. The heat-treatment process has been a well-known technology to make harden the metal surface despite of its inefficiency in productivity and its inherent environmental pollution problem. Therefore, the plasma technology has been applied to the conventional process to improve the above issues and become successful in diminishing the ecological harmfulness. However, the drastic short processing time has been sought to increase the productivity by means of new plasma technology so-called, high temperature pulsed plasma flux (HTPPF). The basic principle and features of this HTPPF will be introduced and the present status of this technology will be described in this paper.

• 한국전산유체공학회지
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• 제19권4호
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• pp.68-74
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• 2014

This computational study features the transient compressible and inviscid flow analysis on a metallic plasma discharge from the opposing composite electrodes which is subjected to pulsed electric power. The computations have been performed using the flux corrected transport algorithm on the axisymmetric two-dimensional domain of electrode gap and outer space along with the calculation of plasma compositions and thermophysical properties such as plasma electrical conductivity. The mass ablation from aluminum electrode surfaces are modeled with radiative flux from plasma column experiencing intense Joule heating. The computational results shows the highly ionized and highly under-expanded supersonic plasma discharge with strong shock structure of Mach disk and blast wave propagation, which is very similar to muzzle blast or axial plasma jet flows. Also, the geometrical effects of composite electrodes are investigated to compare the amount of mass ablation and penetration depth of plasma discharge.

• 한국표면공학회지
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• 제42권3호
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• pp.133-138
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• 2009

Effects of bipolar pulse driving frequency between 50 kHz and 250 kHz on the discharge shapes were analyzed by measuring plasma characteristics by OES (Optical Emission Spectroscopy) and Langmuir probe. Plasma characteristics were modeled by a simple electric field analysis and fluid plasma modeling. Discharge shapes by a continuous dc and bipolar pulsed dc were different as a dome-type and a vertical column-type at the cathode. From OES, the intensity of 811.5 nm wavelength, the one of the main peaks of Ar, decreased to about 43% from a continuous dc to 100 kHz. For increasing from 100 kHz to 250 kHz, the intensity of 811.5 nm wavelength also decreased by 46%. The electron density decreased by 74% and the electron temperature increased by 36% at the specific position due to the smaller and denser discharge shape for increasing pulse frequency. Through the numerical analysis, the negative glow shape of a continuous dc were similar to the electric potential distribution by FEM (Finite Element Method). For the bipolar pulsed dc, we found that the electron temperature increased to maximum 10 eV due to the voltage spikes by the fast electron acceleration generated in pre-sheath. This may induce the electrons and ions from plasma to increase the energetic substrate bombardment for the dense thin film growth.

• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1808-1815
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• 2001

The characteristics of a pulsed plasma jet originating from an electrothermal capillary discharge have been investigate using laser-induced fluorescence (LIF) measurement. Previous emission measurements of a 3.1 kJ plasma jet show trial upstream of the Mach disk the temperature and electron number density are about 14,000 K and and 10$\^$17/ cm$\^$-3/, while downstream of the Mach dick tole values are about 25,000 K and 10$\^$18/ cm$\^$-3/, respectively. However, these values are barred on line-of-sight integrated measurements that may be misleading. Hence, LIF is being used to provide both spatially and temporally resolved measurements. Our recent work has been directed at using planar laser-induced fluorescence (PLIF) imaging of atomic copper in the plasma jet flow field. Copper is a good candidate for PLIF studies because it is present throughout the plasma and has electronic transitions that provide an excellent pump-detect strategy. Our PLIF results to date show that emission measurements may give a misleading picture of the flow field, as there appeals to be a large amount of relatively low temperature copper outside the barrel shock. which may lead to errors in temperature inferred from emission spectroscopy. In this paper, the copper LIF image is presented and at the moment, relative density of atomic copper, which is distributed in the upstream of the pulsed plasma jet, is discussed qualitatively.