• 한국진공학회지
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• 제1권1호
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• pp.32-36
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• 1992

ECR 플라즈마 장치를 설계 제작하였다. ECR 플라즈마의 흐름을 얻기 위해 자기장 의 기울기를 조작할 수 있는 전자석계가 필요하였다. 요크를 사용하면 같은 전류로 자기장 을 1.5배 더 크게 할 수 있었다. 이 장치로 만든 ECR 플라즈마의 특성을 조사하기 위하여, 랑뮈르 탐침을 이용하여 챔버의 축방향을 따라 위치에 따른 전자온도 Te와 전자밀도 Ne의 공간분포를 실험적으로 구하였다.

• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2535-2542
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• 2020

To understand the fundamental parameters of Alvand tokamak, A Rogowski coil with an active integrator was designed and constructed. Considering the characteristics of the Alvand tokamak, the structural and electrical parameters affecting the sensor function, were designed. Calibration was performed directly in the presence of plasma. The sensor has a high resistance against interference of external magnetic fields. Plasma current was measured in various experiments. Based on the plasma current profile and loop voltage signal, the time evolution of plasma discharge was investigated and plasma behavior was analyzed. Alvand tokamak discharge was divided into several regions that represents different physical phenomena in the plasma. During the plasma discharge time, plasma had significant changes and its characteristic was not uniform. To understand the plasma behavior in each of the phases, the Rogowski sensor should have sufficient time resolution. The Rogowski sensor with a frequency up to 15 kHz was appropriate for this purpose.

• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1691-1698
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• 2001

In recent years, significant progress has been made in modeling turbulence behavior in plasma and its effect on transport. It has also been made in diagnostics for turbulence measurement; however, there is still a large gap between theoretical model and experimental measurements. Visualization of turbulence can improve the connection to theory and validation of the theoretical model. One method to visualize the flow structures in plasma is a laser Schlieren imaging technique. We have recently applied this technique and investigated the characteristics of a highly underexpanded pulsed plasma jet originating from an electrothermal capillary source. Measurements include temporally resolved laser Schlieren imaging of a precursor blast wave. Analysis on the trajectory of the precursor blast wave shows that it does not follow the scaling expected for a strong shock resulting from the instantaneous deposition of energy at a point. However, the shock velocity does scale as the square root of the deposited energy, in accordance with the point deposition approximation.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.99-101
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• 2013

The equivalence ratio is measured by LIBS(Laser-induced Breakdown spectroscopy) in hydrocarbon flame and high temperature (${\sim}3200^{\circ}C$) oxyhydrogen flame, where a stoichiometric mixture of hydrogen and oxygen is produced from water through electrolysis. The ratio of the hydrogen and oxygen (H/O) atomic lines intensities is used for quantitatively determining the quivalence ratio. laser energy is evaluated for determining the optimal condition for plasma diagnostics. The minimum laser energy for generating plasma in a laminar premixed hydrocarbon flame was about 70 mJ, whereas oxyhydrogen flame. consequently the irradiated spot of a lower density in high temperature oxyhydrogen flame gave rise to bigger plasma in size, thus limiting the spatial resolution of the LIBS measurement.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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• pp.29-39
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• 1999

Both conventional and PI3 implanters require dense sources for high productivity rate, and small sheath expansion in PI3 besides. The problem of the creation of large volume uniform plasma in PI3 facilities replaces that of beam forming in accelerators. Some aspects of ion extraction in both cases and Langmuir probe plasma diagnostics with be discussed. Plasma parameters of large volume multicusp dc hot cathode and inductively coupled RF plasma sources obtained with Langmuir probe and ion mass analyzer with be presented. Design features and performances of high current Freeman and ECR ion sources will be described.

• Applied Science and Convergence Technology
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• 제24권5호
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• pp.196-202
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• 2015

Human blood consists of 55% of plasma and 45% of blood cells such as white blood cell (WBC) and red blood cell (RBC). In plasma, there are many kinds of promising biomarkers, which can be used for the diagnosis of various diseases and biological analysis. For diagnostic tools such as a lab-on-a-chip (LOC), blood plasma separation is a fundamental step for accomplishing a high performance in the detection of a disease. Highly efficient separators can increase the sensitivity and selectivity of biosensors and reduce diagnostic time. In order to achieve a higher yield in blood plasma separation, we propose a novel fluid wing structure that is optimized by COMSOL simulations by varying the fluidic channel width and the angle of the bifurcation. The fluid wing structure is inspired by the inertial particle separator system in helicopters where sand particles are prevented from following the air flow to an engine. The structure is ameliorated in order to satisfy biological and fluidic requirements at the micro scale to achieve high plasma yield and separation efficiency. In this study, we fabricated the fluid wing structure for the efficient microfluidic blood plasma separation. The high plasma yield of 67% is achieved with a channel width of $20{\mu}m$ in the fabricated fluidic chip and the result was not affected by the angle of the bifurcation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.147-147
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• 2012

Cutoff probe has been used for measuring a plasma density using the cutoff peak which is located at the plasma frequency in the low pressure plasma. However, research on analysis of low frequency region of transmission microwave frequency (TMF) spectrum does not performed even though important plasma parameters are located in the low frequency region, i.e., ion plasma frequency and collision frequency. In this research, we analyzed the low frequency region of the TMF spectrum. Experimental results reveal the effect of plasma parameters on the low frequency region on the TMF spectrum. Based on the response of TMF spectrum from changing of plasma parameters, deduction of the plasma parameters was tried. This comprehensive analysis of TMF spectrum expands applicable area of cutoff probe.

• 진공이야기
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• 제4권2호
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• pp.10-14
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• 2017

In this paper, I present the introduction of cutoff probe in plasma diagnostics. This paper shows the whole progress for the cutoff probe including how to start to develop the cutoff probe in the initial period, what idea has been included during the development, how to evolve the probe during ten years.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.300-300
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• 1999

• 동의생리병리학회지
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• 제20권6호
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• pp.1658-1663
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• 2006

Panax notoginseng (Buck) F.H chen. root (PNS) is used as a therapeutic agent to stop haemorrhages and a tonic to promote health in Korean and Chinses medicine. The pharmacokinetic profiles of the main PNS are still not accurately investigated. Our preliminary aim is to elucidate the pharmacokinetics features of the PNS in rats. Objective of this study is to determine whether PNS affects hepatic microvascular dysfunction elicited by gut ischemia and reperfusion (I/R), since gut I/R causes hepatic microvascular dysfunction, and to investigate the role of nitric oxide (NO). No has been found to be a modulator of the adhesive interactions between platelet and endothelial cells. Male Wistar rats were exposed to 30 min of gut ischemia followed by 60 min of reperfusion. Intravital microscopy was used to monitor the number of non-perfused sinusoids (NPS). In another set of experiments, PNS (1 g/kg pre day intragastrically) was administered to rats for 7 days. In some experiments, dexamethasone (ST) (2 mg/kg per day intravenously) was administered. In control rats, gut I/R elicited increases in the number of NPS, and plasma TNF-${\alpha}$ and ALT activities, and these changes were mitigated by the pretreatment with PNS. Pretreatment with an No synthase inhibitor diminished the protective effects of PNS on the increase in NPS and plasma TNF-${\alpha}$ levels, but not its effect on the increase in plasma ALT activities. Pretreatment with PNS increased plasma nitrite/nitrate levels. The responses caused by gut I/R were attenuated by the pretreatment with ST. Pretreatment with an NO synthase inhibitor did not affect the effect of ST. These results suggest that PNS attenuates the gut I/R-induced hepatic microvascular dysfunction and inflammatory responses such as TNF-${\alpha}$ production in the early phase via enhancement of NO production, and sequential hepatocellular damage via its anti-inflammatory effect like corticosteroid effect.