• 한국안광학회지
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• 제11권4호
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• pp.311-315
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• 2006

플라스마 포커스장치에서 방사되는 전자기파 중에서 X선에 대한 특성을 조사하였다. X선 측정은 pin 포토다이오드와 0.5mm 핀홀카메라로 이루어졌으며, X선 이외의 전자기파를 차폐하기 위해 $25{\mu}m$ 베리륨박막을 사용하였다. X선 발생조건은 방전전압이 15kV이었고, 아르곤 기체압력은 0.12torr 이었다. X선 발생의 재현성이 조사되었고, 방사되는 X선의 온도는 3keV 이상이었다.

• 한국안광학회지
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• 제5권2호
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• pp.163-165
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• 2000

펄스형 방전플라즈마 발생장치인 플라스마 포커스장치에서 발생하는 가시광선영역의 빛을 시간적분 분석법으로 분광 분석하였다. 플라스마 포커스장치는 펄스방전에 의해 전기에너지를 빛에너지로 발생시킬 수 있는 장치이다. 분광분석기는 초점거리가 0.5 m인 모노크로메터를 사용하였다. 시간적분 분석법은 분광된 일정한 범위의 가시광선영역의 파장대를 필름에 현상하여 densitometer로 분석하는 방법이다. 가시광선 발생은 방전전압과 기체압력의 최적조건에서 발생되었는데 방전전압은 13kV이고 아르곤과 헬륨기체가 가시광선영역의 빛을 발생시키는데 사용되었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 추계학술발표회요약집
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• pp.68-68
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• 1998

• 한국분말재료학회지
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• 제11권5호
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• pp.363-368
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• 2004

In the present study, the focus is on the analysis of the effect of the mold dimensions on the temperature distribution of a die during plasma activated sintering. The temperature distribution of a cylindrical mold with various dimensions was measured using K-type thermocouples. The temperature homogeneity of the die was studied based on the direction and dimensions of the die. A temperature gradient existed in the radial direction of the die during the plasma activated sintering. Also, the magnitude of the temperature gradient was increased with increasing sintering temperature. In the longitudinal direction, however, there was no temperature gradient. The temperature gradient of the die in the radial direction strongly depended on a ratio of die volume to punch area.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2687-2696
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• 2023

The fuel operating ranges of fusion tokamak-based power plants are estimated using the improved engineering breakeven equation. The Lawson criterion equations are derived in the form of a triple product with a focus on engineering breakeven and the subbreakeven operating range. The relationship of fuel parameters to the power plant net efficiency is outlined. Analysis shows that the operating ranges of the suitable fuel parameters form a closed area, the size of which affects the net efficiency of the power plant. The obtained fuel operating ranges confirm the well-known fact that DT fuel is currently the only fusion fuel useable in tokamak-based fusion power plants. It is also shown that the energy utilization of pB fuel is possible in the subbreakeven operating range but is conditioned by the very high efficiency of the power plant equipment. For the utilization of DD, DHe3, and pB fuels, the required magnetic fields are indicatively estimated.

• 한국전기전자재료학회논문지
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• 제37권2호
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• pp.188-194
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• 2024

This paper introduces an optimized oxygen (O₂) plasma surface treatment technique to enhance sphere lithography on hydrophobic photoresist surfaces. The focus is on semiconductor manufacturing, particularly the creation of finer structures beyond the capabilities of traditional photolithography. The key breakthrough is a method that makes substrate surfaces hydrophilic without altering photoresist patterns. This is achieved by meticulously controlling the O₂ plasma treatment duration. The result is the consistent formation of nano and microscale patterns across large areas. From an academic perspective, the study deepens our understanding of surface treatments in pattern formation. Industrially, it heralds significant progress in semiconductor and precision manufacturing sectors, promising enhanced capabilities and efficiency.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.332-332
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• 2011

The extreme ultraviolet (EUV) radiation, whose wavelength is from 120 nm down to 10 nm, and the energy from 10 eV up to 124 eV, is widely utilized such as in photoelectron spectroscopy, solar imaging, especially in lithography and soft x-ray microscopy. In this study, we have investigated the plasma diagnostics as well as the debris characteristics between the two types of dense plasma focusing devices with coaxial electrodes of Mather and hypocycloidal pinch (HCP), respectively. The EUV emission intensity, electron temperature and plasma density have been investigated in these cylindrical focused plasma along with the debris characteristics. An input voltage of 5 kV has been applied to the capacitor bank of 1.53 uF and the diode chamber has been filled with Ar gas at pressure ranged from 1 mTorr and 180 mTorr. The inner surface of the cathode was covered by polyacetal insulator. The central anode electrode has been made of tin. The wavelength of the EUV emission has been measured to be in the range of 6~16 nm by a photo-detector (AXUV-100 Zr/C, IRD). The visible emission has also been measured by the spectrometer with the wavelength range of 200~1,100 nm. The electron temperature and plasma density have been measured by the Boltzmann plot and Stark broadening methods, respectively, under the assumption of local thermodynamic equilibrium (LTE).

• 대한지역사회영양학회지
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• 제8권6호
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• pp.822-830
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• 2003

Carotenoid-rich foods focus one's attention on the prevention age-related diseases. This study was conducted to investigate the carotenoid status and look into the factors that affect the bioavailability of carotenoid in 121 elderly nonsmoking Korean women. Carotenoids and lipids in plasma, and nutrient intakes including carotenoid were studied. The mean plasma total-cholesterol, HDL-cholesterol, LDL-cholesterol and triacylglycerol concentrations were 220.0 mg/dl 49.5mg/dl , 139.2mg/dl and 157.4mg/dl , respectively. Significantly positive correlations were found between the plasma lutein + zeaxanthin, lycopene and $\beta$-carotene concentrations and the intake of fruits (r=0.17, r=0.20, r=0.19). However, significantly negative correlations were found between the plasma zeaxanthin, and $\beta$-carotene concentrations that adjusted for carotenoid intakes and intakes of vegetables (r=-0.21, r=-0.19), and between plasma lutein＋zeaxanthin, lycopene and $\beta$-carotene concentrations that adjusted for carotenoid intakes and intakes of fruits (r= -0.21, r=-0.18, r=-0.24). After the adjustment for plasma lipids, there was no correlation between the plasma carotenoid concentrations and the carotenoid-rich foods. However, after adjustment for fiber intake, significantly strong positive correlations were found between the plasma carotenoid concentrations and carotenoid-rich foods. The plasma levels of carotenoid biomarkers (plasma carotenoid concentrations adjusted for dietary fiber intakes) decreased with age, and the plasma levels of lycopene biomarkers (plasma lycopene concentrations adjusted for dietary fiber intakes) increased with regular exercise. However alcohol drinking had no impact. These results suggested that age, physical activity, and dietary fiber intake affected the bioavailability of carotenoid. Therefore, when the elderly have carotenoid-rich foods, they should consider ways of increasing the bioavailability of carotenoid through cooking methods and Physical activity.

• 대한금속재료학회지
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• 제50권7호
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• pp.545-548
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• 2012

The optical and electronic properties of Indium Tin Oxide (ITO) thin films deposited on a RF-plasma treated glass substrate were investigated by X-Ray Photoelectron Spectroscopy (XPS), Ultra-violet Photoelectron Spectroscopy (UPS), Reflected Electron Energy Loss Spectroscopy (REELS). The modification of glass substrates was carried out by varying the time of the plasma surface treatment in an oxygen atmosphere. The focus of this research was to examine how the optical and electronic properties of ITO thin films change with the plasma treatment time. The surface energy increased since the carbon bonds were removed from the surface after the glass substrate received the surface treatment. The ITO thin films produced on the glass substrate with surface treatment showed that the high optical transmittance was approximately 85%. The measured band gap energy was as high as 3.23 eV when the plasma treatment time was 60 s and the work function after the treatment was increased by 0.5 eV in comparison to that before the treatment of 60 s. The ITO thin film exhibited an excellent sheet resistance of $2.79{\Omega}/{\Box}$. We found that the optical and electronic properties of ITO thin films can be improved by RF-plasma surface treatment.

• 대한지역사회영양학회지
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• 제3권5호
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• pp.685-694
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• 1998

This cross-sectional study was conducted to describe the changes of plasma cardiovascular disease(CVD) risk factors in Korea. Overnight fasting plasma levels of total cholesterol, high density lipoprotein(HDL)-cholesterol, triacylglycerol and glucose were analyzed. Blood pressure and anthropometric data were also measured. Health practice factors such as smoking status, alcohol consumption and frequency fo exercise were evaluated by a self-administered questionnaire. Questions regarding dietary habits and food preferences were also asked. Seventy eight percent of the subjects had more than one CVD risk factor. Plasma total cholesterol, triacylglycerol, and fasting blood glucose were significantly increased according to the subjects body mass index$(kg/m^2$, BMI), whereas HDL-cholesterol, low density lipoprotein(LDL)-cholesterol and blood pressure showed no significant differences with BMI. Current smokers had significantly high plasma total cholesterol, LDL-cholesterol and triacylglycerol levels. Alcohol consumption significantly increased plasma total cholesterol and fasting blood sugar, but regular exercise had no effects on the plasma CVD risk factors. Overeating and frequency of fast food consumption were positively correlated with the CVD risk score, whereas intake of grains, meats and vegetables were negatively correlated with that score. A stepwise multiple regression analysis was performed to examine the effects of specific dietary factors on plasma lipid levels. For plasma total cholesterol level, the frequency of fast food intake explained 8% of the variance, followed by habitual overeating, frequency of grain intake and high cholesterol food intake(Model $R^2$=22.4%). For plasma triacylglycerol level, preference of oily foods accounted for 7.5% of the variance, followed by eating breakfast, preference of fruit and frequency of grain intake(Model $R^2$=22.0%). The findings suggest that intervention programs to reduce the risk of CVD should focus on health practice through reducing BMI, smoking cessation and moderate or no alcohol drinking. Moreover, desirable dietary habits such as eating breakfast, not overeating and reduced intake of fast food may improve CVD risk.