• 제목/요약/키워드: Thin filament

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HF-CVD법에 의한 세라믹스 기판에의 다이아몬드박막 합성과 그 밀착성 평가 (Diamond Film Deposition on Ceramic Substrates by Hot-Filament CVD and Evaluation of the Adhesion)

  • 신순기
    • 한국재료학회지
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    • 제10권8호
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    • pp.575-580
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    • 2000
  • Ta(TaC) 필라멘트를 이용한 HF-CVD 법에 의하여 $Si_3N_4$, SiC, WC, $Al_2O_3$를 기판으로 다이아몬드 박막을 증착하고, 그 밀착특성을 평가하였다. 로내의 $CH_4$농도를 10%로 높게 하였을 경우에는 막중에 graphitic(amorphous) carbon이 생성됨을 확인할 수 있었다. 박막을 $12\mu\textrm{m}$ 정도까지 두껍게 하면, WC기판에서는 부분적 박리형상이 관찰되었으나, $Si_3N_4$를 기판으로 하였을 경우에는 안정한 박막을 얻을 수 있었다. Indentation test 결과로부터 grainding에 의한 기판표 처리가 밀착성 향상에 효과적이라는 것을 알 수 있었다. 또 compression topple test에서는 박막의 두께는 밀착성과 반비례의 관계를 가지는 것을 알 수 있었다. 수 있었다.

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Synthesis of diamond thin films by hot-filament C.V.D

  • 최진일
    • 한국결정성장학회지
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    • 제8권2호
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    • pp.227-232
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    • 1998
  • Si, Mo 등을 substrate로 하고 Hot-Filament C.V.D법으로 저압으로 다이아몬드 박막을 생성시킬 때 탄화수소의 부착과정, 핵생성 및 성장을 조사하였다. 특성은 substrate의 종류, 온도, 압력, 유속 및 $CH_4-H_2$가스의 몰분율과 같은 process 변수로 조사하였으며 다이아몬드는 Ra-man spectroscopy로 측정하였다. 특히 다이아몬드 핵생성과 성장은 scratch와 같은 결함이 있는 곳에 발생하였고 표면확산 등이 핵생성 초기단계에서 중요한 역할을 하였다.

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SiC 필라멘트를 이용한 소염 직전의 확산화염 온도 계측 (SiC filament Pyrometry in Near Extinction Diffusion Flame)

  • 심성훈;신현동
    • 대한기계학회논문집B
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    • 제26권11호
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    • pp.1481-1487
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    • 2002
  • The thin SiC filament technique has been employed to identify the possibility of measuring flame temperature, and especially unstable near-extinction flame temperature in an oxidizer deficient ambience, by comparing the relative visible (non-IR) luminosities of SiC filaments with thermocouple measured temperature in co-flowing, laminar propane/air diffusion flames. The results show good agreement between the digitized relative visible luminosity profiles of the SiC filaments and temperature profiles measured using a thermocouple at temperatures above $700^{\circ}C$, although, a non-linear calibration is probably required far the whole temperature range. The highest radial peak temperature exists near to the nozzle exit. and the centerline temperatures were virtually unchanged with increasing flame height in an oxidizer deficient near-extinction flame.

Growth and Characterization of Vertically well Aligned Crbon Nanotubes on Glass Substrate by Plasma Enhanced Hot Filament Chemical Vapor deposition

  • Park, Chong-Yun;Yoo, Ji-Beom
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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    • pp.210-210
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    • 2000
  • Vertically well aligned multi-wall carbon nanotubes (CNT) were grown on nickel coated glass substrates by plasma enhanced hot filament chemical vapor deposition at low temperatures below 600$^{\circ}C$. Acetylene and ammonia gas were used as the carbon source and a catalyst. Effects of growth parameters such as pre-treatment of substrate, plasma intensity, filament current, imput gas flow rate, gas composition, substrate temperature and different substrates on the growth characteristics of CNT were systematically investigated. Figure 1 shows SEM image of CNT grown on Ni coated glass substrate. Diameter of nanotube was 30 to 100nm depending on the growth condition. The diameter of CNT decreased and density of CNT increased as NH3 etching time etching time increased. Plasma intensity was found to be the most critical parameter to determine the growth of CNT. CNT was not grown at the plasma intensity lower than 500V. Growth of CNT without filament current was observed. Raman spectroscopy showed the C-C tangential stretching mode at 1592 cm1 as well as D line at 1366 cm-1. From the microanalysis using HRTEM, nickel cap was observed on the top of the grown CNT and very thin carbon amorphous layer of 5nm was found on the nickel cap. Current-voltage characteristics using STM showed about 34nA of current at the applied voltage of 1 volt. Electron emission from the vertically well aligned CNT was obtained using phosphor anode with onset electric field of 1.5C/um.

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혼방 및 연사방법에 따른 춘하용 아크릴 니트소재의 주관적 감성평가 (The Subjective Sensibility Evaluation of the S/S Acrylic Fabrics Knitted with Various Blended and Twisted Yarns)

  • 김미진;박명자
    • 한국의상디자인학회지
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    • 제9권1호
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    • pp.35-50
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    • 2007
  • We performed the subjective sensibility evaluation on knitted fabrics by the following procedures: setting acrylic fabrics used for S/S among fabrics as basis, five kinds of blended spun yarns and four kinds of twisted filament yarns made by different twisting methods then, we did questionnaire survey targeting sixty females in the expert groups. Utilizing SPSS 12.0, correlation, ANOVA, Duncan, and Multidimensional Standard way were analyzed. The results are as following. First, the result of evaluating on preferred knits followed by the analysis of the sense factor, in the 'drape sense', the acrylic/rayon blended knit was preferred as the most flexible, pliable, and elastic knit; in weight/bulk factor, the acrylic filament knit the most twisted was preferred as the least bulk, thin, cool and transparent knit; in 'surface depression sense' factor, A(F)W acrylic/wool blended knit was preferred as the most haggard, straight, dry knit. Second, the result of evaluating on preferred knits followed by the analysis of the sensibility factor, in the 'neatness' the acrylic filament hit was preferred as the most clean, neat and delightful knit; in the 'comfortableness', the acrylic/wool blended knit was preferred as the most natural, stable, and comfortable knit. Third, according to the result of evaluating on preferred knits as the spring and summer, generally the acrylic filament twisted yarn knits were more preferred than the acrylic blended yarns. However the preference on the kinds of the acrylic twisted filament yarn showed that there is a little difference on the acrylic blended yarn knit.

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Vasorelaxing Effect of Hypoxia via Rho-kinase Inhibition on the Agonist-specific Vasoconstriction

  • Je, Hyun-Dong;Shin, Chang-Yell
    • Biomolecules & Therapeutics
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    • 제16권3호
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    • pp.249-254
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    • 2008
  • The present study was undertaken to determine whether hypoxia influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Hypoxia significantly inhibited fluoride-induced contraction regardless of endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction suggesting that other pathway such as $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, hypoxia significantly decreased fluoride-induced increase of phospho-myosin-targeting subunit of myosin light chain phosphatase (pMYPT1). Interestingly, hypoxia didn't inhibit significantly phenylephrine-induced contraction suggesting that myosin light chain kinase (MLCK) activity or thin filament regulation is less important on the hypoxia-induced vasorelaxation in the denuded muscle than Rho-kinase activity. In conclusion, this study provides the evidence and possible related mechanism concerning the vasodilation effect of hypoxia on the agonist-specific contraction in rat aortic rings regardless of endothelial function.

Poly-Si Thin Film Solar Cells by Hot-wire CVD

  • Lee, J.C.;Chung, Y.S.;Kim, S.K.;Yoon, K.H.;Song, J.S.;Park, I.J.;Kwon, S.W.;Lim, K.S.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.1034-1037
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    • 2003
  • Microcrystalline silicon(c-Si:H) thin-film solar cells are prepared with intrinsic Si-layer by hot wire CVD. The operating parameters of solar cells are strongly affected by the filament temperature ($T_f$) during intrinsic layer. Jsc and efficiency abruptly decreases with elevated $T_f$ to $1400^{\circ}C$. This deterioration of solar cell parameters are resulted from increase of crystalline volume fraction and corresponding defect density at high $T_f$. The heater temperature ($T_h$) are also critical parameter that controls device operations. Solar cells prepared at low $T_h$ ($<200^{\circ}C$) shows a similar operating properties with devices prepared at high $T_f$, i.e. low Jsc, Voc and efficiency. The origins for this result, however, are different with that of inferior device performances at high $T_f$. In addition the phase transition of the silicon films occurs at different silane concentration (SC) by varying filament temperature, by which highest efficiency with SC varies with $T_f$.

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김확 묘 출토직물 제직 특성 연구 (Characteristics of the Fabrics Excavated from the Tomb of Kimwhoak)

  • 조효숙;이은진
    • 복식
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    • 제61권2호
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    • pp.88-101
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    • 2011
  • This study emphasizes on the characteristics of the excavated fabrics from the tomb of Kimwhoak in the late 16th and early 17th centuries. All of 118 kinds of fabrics are used in excavated costume from the tomb of Kimwhoak. Classified by its materials, it is divided into small groups as follows: 63 pieces of spun silk tabby(53.6%), 14 of spun yarn silk(11.9%), 13 of thin filament silk tabby(11.0%), 8 of thin silk tabby(6.8%), 4 of satin without pattern(3.4%), 3 of filament silk tabby(2.5%), 3 of twill without pattern(2.5%), 2 of satin damask(1.7%), 2 of mixture fabric with silk and cotton(1.7%), and 2 of ramie fabric(1.7%), 1 of simple gauze without pattern(0.8%), 1 of damask with supplementary gold thread(0.8), 1 of cotton(0.8%), 1 of etc(0.8%). Classified by ways of weaving: 106 pieces of plain weave(89%), 6 of satin weave(5%), 3 of twill weave (3%), 1 of gauze weave(1%), 1 of compound weave(1%) and etc(1%). In point of patterns, the most of textiles are without pattern, there are only two of them are patterned textile. such as lotus patterns with vine, peony patterns with vine. Their patterns are very similar to those of other tombs in the same age.

진주류씨(晉州柳氏) 합장 묘 출토직물에 관한 연구 (The Characteristics of Excavated Fabrics from the Couple's Tomb of Jinju Ryu)

  • 조효숙;이은진
    • 대한가정학회지
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    • 제45권2호
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    • pp.51-62
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    • 2007
  • This study explicates some properties of the fabrics used in the 16th century by examining and analyzing the 90 pieces of fabric excavated from the graves of Mr. Ryu of Jinju and his wife Mrs. Park of Euiin. The fabrics were classified into silk tabby(紬), thin silk tabby, satin damask(段), complex gauze(羅), mixture fabric with silk and cotton(絲棉交織), cotton(棉布) etc. Compared to other contemporary fabrics excavated previously, the fabrics unearthed from the couple's graves presented very naive feelings. Patterned satin damask occupied a small portion. In the case of plain fabric, little filament silk tabby(絹) or thin filament silk tabby(細紬) was unearthed. Important data on the history of Korean costumes are provided by the noteworthy, first-ever excavation of a small cap made of complex gauze(羅) and the tiger-leopard embroidered patches called hyoongbae(胸背), which were worn on the front and back of official robes made of tabby with supplementary gold thread(金線). Only 3 pattern types could be clearly identified in form, cloud pattern, lotus and vine pattern(蓮花蔓草), and small flower and treasures pattern(七寶細花). These three patterns are very similar to those of other 16th century fabrics unearthed previously in terms of the form and arrangement of patterns.

MgO 박막의 $\gamma$ 계수 측정용 이온빔원의 시작 및 동작특성 (Some Characteristics of Ion Beam Source for $\gamma$-Coefficient Measurement of MgO Thin Film)

  • 정신수;김준호;김희제;조정수;박정후;박차수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 E
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    • pp.1752-1754
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    • 1997
  • The Kaufman type ion beam source with focusing lens was prepared to measure $\gamma$-coefficient of MgO thin film. Initial discharge of the system was started with the discharge voltage of 25V, the cathode filament current of 5.5A at the constant magnetic field of 150G. The system shows the maximum ion current density of $120{\mu}A/cm^2$, energy dispersion of 200eV and beam divergence of $30^{\circ}$ under the condition of Ar gas pressure $2.5{\times}10^{-4}Torr$, the beam voltage of 500V, the discharge voltage of 90V, the accelerator voltage of -200V and the cathode filament current of 6.1A. When the focusing lens was installed onto the ion beam source, the spreadness diameter of ion beam was about 10mm.

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