• 제목/요약/키워드: $^{211}At$

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Silicon Carbide Coating by Thermal Decomposition of tetramethylsilane

  • YOON Kyung-Hoon
    • Proceedings of the Korean Ceranic Society Conference
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    • 한국세라믹학회 1986년도 Priceedings Of The Third Korea-Japan Seminar On New Ceramics
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    • pp.211-225
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    • 1986
  • Silicon carbide coating has been studied using a graphite substrate, a mixture of tetramethylsilane and hydrogen or argon at deposition temperature (T) of 950 to $1200^{\circ}C$ total pressure of 20 to 50 torr and carrier gas flow rate of 0 to 901/h. Deposition kinetic study has shown that a transition, from a surface reaction limited process to a diffusion limited one, takes place near $1100^{\circ}C$. Deposition rate depends directly upon the experimental parameters. The influence of the main process parameters is also discussed to relate the physiochemical properties of the coating to the deposition conditions.

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Backscattering of TE Waves by Periodical Surfaces filled with Multiple Dielectric Layers (다층 유전체로 채워진 주기 구조에 의한 TE파의 후방 산란)

  • 손형석;박대우;송충호;이상설
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.211-214
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    • 1999
  • Periodical surfaces with the sawtooth profile are studied on their backscattering by the TE plane wave incident. The backscattering is calculated by the mode-matching method. The surfaces are perfect conductor and are covered with dielectric materials to make a flat surface. It is observed that a cover filled with multiple dielectric layers can be used to reduce the backscattering at an arbitrary incident angle.

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Characteristics of Ambient Aerosol Sizers (대기 에어로졸 입경분포 측정기의 특성 비교)

  • 배귀남;김민철;지준호;이승복;문길주
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 한국대기환경학회 2003년도 추계학술대회 논문집
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    • pp.211-212
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    • 2003
  • 지금까지는 주로 대기질 기준을 근거로 24시간 평균 TSP(total suspended particulates), PM$_{10}$, PM$_{2.5}$를 측정하여 왔다. 대기 에어로졸의 농도나 입경분포에 영향을 미치는 배출량, 기온, 상대습도, 풍향, 풍속, 혼합고 등이 12~24시간 이내의 스케일로 변한다(Shen et al., 2002). 그러므로, 대기 에어로졸의 일변화 특성을 파악하기 위하여 실험실에서 사용되던 실시간 에어로졸 입경분포 측정기가 대기 에어로졸 모니터링에 활용되고 있으며(배귀남 등, 2003; Woo et at., 2001; Laitinen et al., 1996), 최근에는 대기 에어로졸을 모니터링을 목적으로 개발된 제품이 시판되고 있다.(중략)략)

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NUMBER OF THE NONTRIVIAL SOLUTIONS OF THE NONLINEAR BIHARMONIC PROBLEM

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • 제18권2호
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    • pp.201-211
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    • 2010
  • We investigate the number of the nontrivial solutions of the nonlinear biharmonic equation with Dirichlet boundary condition. We give a theorem that there exist at least three nontrivial solutions for the nonlinear biharmonic problem. We prove this result by the finite dimensional reduction method and the shape of the graph of the corresponding functional on the finite reduction subspace.

Effect on the Orientation of Poly(trimethylene terephthalate) Fibers in Drawing Conditions(II) (연신조건이 PTT 섬유의 배향에 미치는 영향(II))

  • Kang, Seok-Jin;Kim, Kyoung-Hou;Cho, Hyun-Hok
    • Proceedings of the Korean Fiber Society Conference
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    • 한국섬유공학회 2003년도 가을 학술발표회 논문집
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    • pp.211-212
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    • 2003
  • Since Poly(trimethylene terephthalate)(PTT)'s synthetic method was first reported in 1941 by Whinfield et at. [l], many scientifical studies have worked for commercializing. Nevertheless, it was never commercialized because of many unstable sources. Like report of preceeding researchers, PTT was known to us that it had unique crystal structure such as coiled spring due to conformation of tggt. (omitted)

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Phase Equilibria in the System Y2O3-BaO-CuO (Y2O3-BaO-CuO계의 상평형)

  • 오승호;최종건;오근호;김인성
    • Journal of the Korean Ceramic Society
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    • 제25권1호
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    • pp.83-87
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    • 1988
  • Phase relationships in the system Y2O3-BaO-CuO were investigated at 950$^{\circ}C$ by XRD, SEM and EPM analysis. It was found that there was a new phase that has not been awared yet, closely near the range of sharing 123 and 211 compounds.

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Electric Properties of Superconductors for Electric Power Transmission

  • Lee Sang-Heon
    • KIEE International Transactions on Electrophysics and Applications
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    • 제5C권5호
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    • pp.211-213
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    • 2005
  • [$SiO_2$] film coated as a passivation layer for YBCO based electronic devices is investigated by measuring the micro wave properties of micro strip line resonators. The $SiO_2$ film coated resonators are compared with coated resonators for two degradation conditions, a $200^{\circ}C$ annealing in air and an exposure to air at $85^{\circ}C\;85\%$ relative humidity. The $SiO_2$ film reduces the YBCO thin film degradation caused by oxygen stoichiometry change and reaction with water.

Optimization of Lactic Acid Production from Kitchen Refuses (음식물쓰레기를 이용한 젖산 생산의 최적화)

  • 이백석;윤현희;김은기
    • KSBB Journal
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    • 제16권2호
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    • pp.207-211
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    • 2001
  • Statistical experimental design methods were employed to select the cultivation factors influencing latic acid production during the fermentation of kitchen refuses. Working volume and pH swings were identified as the main factors affecting lactic acid production. Optimum pH swing was pH 7.8 and working volume was 125 mL in a 250 mL flask. Under optimum condition, lactic acid was produced at 21.8 g/L, which was 6.2 times higher than produced during uncontrolled fermentation.

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Survey on the Occurrence of Scattering Dust at Construction Sites (건설현장의 비산먼지 발생실태에 관한 설문조사)

  • Han, Jae Goo;Kim, Young Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 한국건축시공학회 2020년도 봄 학술논문 발표대회
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    • pp.210-211
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    • 2020
  • In this study, a questionnaire survey on the occurrence status of fine dust in urban construction sites and the response level was conducted. Based on the results of the survey, it is intended to be used as basic data for establishing a method to reduce fine dust in construction sites.

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