• 제목/요약/키워드: plasma frequency

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정상체중과 비만인 대학생의 UCP 2 유전자 다형성, 식습관, 비만도 및 체성분의 비교 연구 (Comparisons of UCP2 Polymorphism, Dietary Habits, and Obesity Index in Normal and Obese University Students)

  • 안명수;장인엽;김경희
    • 한국식생활문화학회지
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    • 제22권4호
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    • pp.404-413
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    • 2007
  • This study was carried out to compare UCP2 polymorphism, dietary habits, and obesity index in normal and obese university students. The survey was carried out using self-questionnaires collected from the 126 normal and 60 obese university students. The results are summarized as follows. Breakfast was skipped in 43.7% of normal and 49.3% of obesity students and it appeared obese students eat faster than normal students. The percentage of weight control experience were 49.2 and 71.0 in the normal and obese students, respectively. Blood levels of lipid profiles(triglyceride, LDL cholesterol, and HDL cholesterol), hemoglobin, AST and ALT were anaylzed. In UCP2 genes, the frequency of deletion homozygote(DD) was 71.5%, heterozygote(DI) was 26.9% and insertion homozygote(II) was 1.6%. Plasma levels of triglyceride, total cholesterol, LDL cholesterol, and HDL cholesterol of normal students were 79.06, 172.25, 100.86 and 57.03 mg/dl, and those of obese students were 93.06, 173.22, 101.22 and 54.39 mg/dl, respectively. Blood parameters were in normal range in both group. Plasma triglyceride, total cholesterol and LDL cholesterol levels of obese students were higher than those of normal students. On the other hand, plasma HDL cholesterol levels of obese students were lower than those of normal students. Plasma levels of AST and ALT were in normal range in both group. However, AST and ALT levels of obese students were higher than that of normal students. Thus, it was recommended for them to have a nutritional education program to improve their dietary and living habits for obese students’health. Nutritional education program should also be organized practically and systematically.

운전압력 변화에 따른 마이크로파 공기 플라즈마의 특성연구 (Characteristics of Microwave Air Plasma With a Wide Range of Operating Pressures)

  • 조정현;장봉철;박봉경;김윤환;정용호;김곤호
    • 한국진공학회지
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    • 제11권1호
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    • pp.68-75
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    • 2002
  • 본 연구에서는 운전압력을 1 mTorr~760 Torr까지 변화시키며 발생되는 마이크로파 공기 플라즈마의 특성을 관찰하였다. 마이크로파 공기 플라즈마 발생을 위하여 마이크로파의 전송선로인 도파관은 $TE_{01}$ mode로 설계 및 제작하였으며, 가정용 전자렌지에 사용되는 마그네트론을 이용하여 AC-type microwave source를 제작하였다. 입력 전력은 370 W로 일정하게 유지하였으며, 이때 발생하는 플라즈마의 특성 관찰은 고속주사 정전탐침과 OES (Optical Emission Spectroscopy)를 이용하였다. 최소 절연파괴 전기장의 세기(breakdown E-field)를 가지는 압력인 500 mTorr를 기준으로 발생 플라즈마의 특성은 많은 변화를 보였으며 이 압력은 입력주파수($\omega$)와 충돌주파수($V_c$)가 일치하는 조건이었다. 이때 공기의 유효충돌 단면적은 $9.23\times10^{-l6}\textrm{cm}^2$으로 계산되었다. 운전압력 500 mTorr 이하의 영역에서 절연파괴 전기장의 세기는 약 $5.7\times10^4$V/m-Torr의 값을 갖으며 압력에 반비례하여 감소하였고, 500 mTorr에서 전기장은 12.5 kV/m로 최저 값을 갖고, 500 mTorr 이상의 영역에서는 약 43 V/m-Torr로 압력에 비례하여 증가하였다. OES 측정결과 마이크로파 공기 플라즈마에서 발생되는 주요 이온의 성분은 산소, 아르곤, 질소였으며, 특히 500 mTorr 이하의 영역에서는 산소와 아르곤 이온의 발생이 지배적이었다. 공기내의 산소(O(II))의 이온온도는 압력이 증가함에 따라 약 1.2 eV에서 0.5 eV로 감소하는 경향을 보였다. 정전 탐침 측정 결과는 500 mTorr 이하의 영역에서 플라즈마 밀도가 증가하는 경향을 보였으며 500 mTorr 이상의 영역에서 플라즈마 밀도는 비교적 낮았다.

Etching characteristics of ArF and EUV resists in dual-frequency superimposed capacitively coupled $CF_{4}/O_{2}/Ar$ and $CF_{4}/CHF_{3}/O_{2}$/Ar plasmas

  • 권봉수;김진성;박영록;안정호;문학기;정창룡;허욱;박지수;이내응;이성권
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2009년도 춘계학술대회 논문집
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    • pp.252-253
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    • 2009
  • In this study, the deformation and etch characteristics of ArF and EUV photoresists were compared in a dual frequency superimposed capacitively coupled plasma (DFS-CCP) etcher systems using $CF_{4}/O_{2}/Ar$ and $CF_{4}/CHF_{3}/O_{2}/Ar$ mixture gas chemistry which are typically used for BARC open and $Si_{3}N_{4}$ teching chemistry, respectively. Etch rate of the resists tend to increase with low-frequency source power ($P_{LF}$) and high-frequency source ($f_{HF}$). The etch rate of ArF resist was hgither than that of EUV resist.

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AC-PDP의 광효율 향상을 위한 고주파 구동회로에 관한 연구 (A Study on High Frequency Sustaining Driver for Improving Luminance Efficiency of AC-PDP)

  • 최성욱;한상규;문건우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2005년도 전력전자학술대회 논문집
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    • pp.380-384
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    • 2005
  • Plasma display panel (PDP) has a serious thermal problem, because the luminance efficiency of the conventional PDP is about 1.5 lm/W and it is less than $3{\sim}5$ lm/W of cathode ray tube (CRT). Thus there is a need for improving the luminance efficiency of the PDP There are several approaches to improve the luminance efficiency of the PDP and we adopt the driving PDP at high frequency range from 400 kHz up to over 700 kHz. Since a PDP is regarded as an equivalent inherent capacitance, many types of sustaining drivers have been proposed and widely used to recover the energy stored in the PDP. However, these circuits have some drawbacks for driving PDP at high frequency range. In this paper, we investigate the effect of the parasitic components of PDP itself and driver when the reactive energy of panel is recovered. Various drivers are classified and evaluated whether it is suitable for high frequency driver, and finally current-fed type with do input voltage biased is proposed. This driver overcomes the effect of parasitic component in panel and driver and fully achieves ZVS of all full-bridge switches and reduces the transition time of the panel polarity.

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임신부의 비타민 $B_{6}$ 섭취와 모체와 제대혈 및 태반 조직의 비타민 $B_{6}$농도 (Maternal Vitamin $B_{6}$ Intake and Vitamin $B_{6}$ Level in Maternal, Umbilical Cord Plasma and Placenta)

  • 안홍석;이금주;정환욱
    • Journal of Nutrition and Health
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    • 제35권3호
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    • pp.322-331
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    • 2002
  • 본 연구는 정상만기분만 임신부 (30명)와 그들의 신생아를 대상으로 임신부와 비타민$B_{6}$ 섭취양상과 모체와 신생아 제대혈장 및 태반조직내의 비타민$B_{6}$ 농도를 측정하고 이들 농도와 임신결과와의 상관성을 조사하며, 모체에서 태아로 비타민$B_{6}$가 이동될 때, 태반의 역할을 규명하고자 하였다. 임신부의 평균 연령과 임신 전 체중 및 신장은 각각 25.9세, 53.8kg 및 161 cm 였으며, 임신 전 체중 및 신장은 각각 25.9세, 53.8 kg 및 161cm 였으며, 임신 전 BMI는 20.7kg/$m^2$로 정상 범위였다. 수축기와 이완기 평균 혈압은 122.5 mmHg 와 75.2mmHg의 결과로 안정적인 수준이었으며 헤모글로빈 농도와 헤마토크리트치는 12.1g/dl와 36.1%로 양호하였다. 연구대상자 중 93.3%에 해당하는 임신부가 영양보충제를 복용했으며 이 중 85.7%가 엽산과 철분이 포함된 빈혈 치료제를 이용한 것으로 조사되었다. 영양보충제의 평균 복용기간은 16.3주였다. 임신부가 1일 평균 열량 섭취량은 2189.5kcal로 권장량의 93.2%였으며, 단백질은 79.3g(113.3%)으로 권장량을 상회하였다. 비타민 B$_{6}$의 평균 섭취량은 권장량은 91.4%인 1.7mg이었고, 비타민 $B_{6}$의 평균 섭취량은 권장량은 91.4%인 1.7mg이었고, 비타민 $B_{6}$ 영양밀도와 단백질 g 당 섭취량은 각각 0.8와 0.02mg으로 양호한 결과였다. 그러나, 비타민$B_{6}$의 주된 공급식품이 곡류 및 전분류 (50%)와 야채 및 과일류 (33%)로 식물성 식품이 대부분이었다. 임신 말 모체 혈장과 신생아 제대혈장의 PLP 농도는 각각 16.7$\pm$4.1 nmol/l와 61.3$\pm$19.8 nmol/l로 제대혈장의 PLP 농도가 유의적으로 높았으며, 태반조직의 PLP 농도는 898.6$\pm$159.2ng/g으로 혈장의 PLP 농도에 비해 매우 높은 값을 보였다. 모체와 태반조직 및 신생아 제대혈장간 PLP 농도의 상관성을 조사한 결과, 모체 혈장과 태반 조직간 (p<0.0001), 태반 조직과 신생아 제대혈장간 (p<0.05), 모체 혈 장과 제대혈장간(p<0.05) 유의적인 양의 상관관계가 있었다.

AC-PDP Sustain Driver using Bidirectional Switches

  • Kang, Feel-Soon
    • Journal of Electrical Engineering and Technology
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    • 제6권1호
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    • pp.86-93
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    • 2011
  • To minimize the cost and power consumption of PDP TV, a practical sustain circuit topology is presented with an address-and-display-period-separated driving scheme. The proposed sustain driver employs bidirectional switches to reduce the number of components. Operational principles and corresponding features are illustrated and compared with the conventional approach. The valuable contributions of the proposed high-performing sustainer has been proven by computer-aided simulations and experiments by using a prototype equipped with 7.5-inch diagonal panel operated at 200 kHz switching frequency.

Thermal and Stress Analysis of The Faraday Shield in KSTAR ICH System

  • Yoon, B.J.;Han, J.M.;Jeong, S.H.;Yoon, J.S.;Hong, B.G.
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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    • pp.935-940
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    • 1998
  • The Korea Superconducting Tokamak Research (KSTAR) tokamak will have 6 MW of radio-frequency (rf) heating in the ion cyclotron range of frequencies (ICRF). The response of the antenna to the heat loads is analyzed and the resulting stresses in the Faraday shield during the normal operation is calculated. Various heat loading conditions including in the analyzes are the heat loads from the plasma, the ripple-trapped beam particles and the rf loss.

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High Efficacy and High Speed Addressing of a Spatial Positive Column Discharge PDP

  • Shiga, T.;Mikoshiba, S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.115-118
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    • 2007
  • Luminous efficacy of 6.0 lm/W has been realized by introducing a spatial positive column discharge together with delayed D pulses, shared sustain pulse voltage, and low sustain frequency drive. Also a high speed addressing of $0.25{\mu}s$ was achieved. The luminance was $157cd/m^2$, which is high enough for a 260-in. FHD display.

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글로우방전을 이용한 가스크로마토그라프 검출기의 개발 (Glow Discharge as Detector for Gas Chromatography)

  • 김효진;박일영;장성기;김박광;박만기
    • 약학회지
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    • 제37권1호
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    • pp.76-83
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    • 1993
  • The changes in discharge current, emission and/or oscillation frequency of the electric oscillation of a glow discharge are the potential sensitive measure of the concentration of an impurity in the argon plasma supporting gas. A single jet enhanced glow discharge has been interfaced with the gas chromatograph via 1/8" O.D. tube with a heating pad to study the changes in discharge current. To investigate the optimum operating conditions of the glow discharge system as detector for gas chromatography, pressure, gas flow rate, discharge current, distance between the anode and the cathode have been studied.

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