• Title/Summary/Keyword: Carrier free

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막여과지에 의한 무단체 이트륨-90에 관한 연구 (Studies on Carrier-Free Yttrium-90 with Membrane Filters)

  • 제원목
    • 대한화학회지
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    • 제14권4호
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    • pp.347-355
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    • 1970
  • The state of carrier-free yttrium-90 has been studied by filtration method with membrane filters. The studies include the adsorption ratio of carrier-free yttrium-90 on membrane filters by the change of PH, concentration of yttrium-90, and the pore size of member filters. The adsorption followed to Freundlich adsorption isotherm. The adsorption mechanism was proposed by the adsorption of transient state as an ionic form of $Y^{3+}$, and the experimental results were explained satisfactorily by the proposal. The adsorbed state of yttrium was present in the forms of yttrium such as $Y^{3+},\;Y(OH)^{3+},\;Y(OH)^{2+},\;Y(OH)^+_3,\;and\;Y(OH)_3$,and the existing ratios of the forms of yttrium were sharply changed by PH. It seems to be valid tha the carrier-free yttrium-90 exists mostly in $Y^{3+}$ state.

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제어기 무장착 운송대를 위한 선형운동 자기부상 운송시스템 (Magnetically levitated transport system for a controller-free carrier)

  • 손영욱;박기환
    • 대한기계학회논문집A
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    • 제21권12호
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    • pp.2196-2208
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    • 1997
  • In this work, a magnetic levitation (maglev) system is developed to transport a wafer between semiconductor fabrication process modules in clean rooms to take advantages of eliminating particle and oil contamination that normally exist in conventional transport systems due to contact motion of mechanical components. A main feature of the maglev system developed in this work is that a controller and power supplying part are not mounted on the moving carrier but on the stationary track, which is defined a controller-free carrier, to reduce carrier's weight. Iron-core electromagnets and irons are used for levitation, and air-core electromagnets and permanent magnets are used for stabilization. Analysis, design, and modeling of the magnetically levitated transport system are presented. The performance of the maglev system is experimentally demonstrated.

MAGNETOTRANSPORT OF SEMIMETALLIC Bi THIN FILMS CROWN BY ELECTROPLATING AND SPUTTERING

  • M. H. Jeon;Lee, K. I.;Lee, K. H.;J. Y. Chang;K. H. Shin;S. H. Han;Lee, W. Y.;J. G. Ha
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2002년도 동계연구발표회 논문개요집
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    • pp.150-151
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    • 2002
  • In recent years, semi-metallic Bismuth (Bi) has attracted significant attention due to very large magnetoresistance (MR) at room temperature originating from long carrier mean free path l and small effective carrier mass m*[1, 2]. In particular, the MR behavior and long carrier mean free path l in Bi thin films can be exploited for spintronic devices, e.g. magnetic field sensors and spin-valve transistors. In present work, we present the magnetotransport properties of the electroplated and sputtered Bi thin films in the temperature range 4-300 K. (omitted)

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고체입자가 부상된 자유 횡분류 유동에 대한 전산모사 연구 (I) -2상 분류궤적과 운동량 전달기구- (Numerical Simulation Study on Gas-Particle Two-Phase Jets in a Crossflow (I) -Two-Phase Jet Trajectory and Momentum Transfer Mechanism-)

  • 한기수;정명균
    • 대한기계학회논문집
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    • 제15권1호
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    • pp.252-261
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    • 1991
  • 본 연구에서는 2상 횡분류의 평균 유동특성을 비교적 정확히 예측할 수 있는 방법을 제시하는데 있다. 이를 위하여 2상 기체 분류속에 유입되는 자유흐름의 질량 유입을 Keffer와 Baines의 유입함수를 이용하기로 하며, 입자와 기체분류사이의 궤적 이탈을 고려하기로 한다. 이런 모델을 이용하여 2상 횡분류의 분출초기의 입자와 기 체분류의 속도비(particle to gas velocity ratio at the jet exit)가 유동에 미치는 영향을 알아보고자 한다.

비등방성 반도체 양자우물에서의 자유전자 흡수에 의한 광자의 흡수계수의 모델링 (Modeling of free carrier absorption coefficients in anisotropic semiconductor quantum well structures)

  • 김경염
    • 한국광학회지
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    • 제10권1호
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    • pp.80-86
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    • 1999
  • 비등상성 반도체 양자우물에서의 자유전자 흡수에 의한 광자의 흡수계수를 모델링하였다. Intravalley scattering과 interalley scattering에 의한 자유전자 흡수가 모두 고려되었고 양자우물내의 각각의 부밴드가 광자의 흡수에 기여하는 정도도 따로 계산되었다. 또한 이 모델의 타당성을 검증하기 위해, Si에 $\delta$-도핑을 이용하여 형성한 얀자우물에 대하여 시물레이션을 수행하고 문헌의 실현결과와 비교하여 그 적절성을 보였다.

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MC-50 싸이클로트론을 이용한 In-111 제법 개발 (The Production of Carrier Free Indium-111 with MC-50 Cyclotron)

  • 전권수;서용섭;양승대;채종서;지광수;이종두
    • 대한방사선기술학회지:방사선기술과학
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    • 제13권2호
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    • pp.43-49
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    • 1990
  • [ $^{111}$ ]In has wide applications in nuclear medicine for labelling and in-vivo distribution studies. A method is developed for the production of carrier free $^{111}$In using the reaction $^{nat.}Cd(p,\;xn)$ $^{111}$In with MC-50 cyclotron. Carrier free $^{111}$In was separated from the irradiated metallic cadmium by liquid-liquid extraction and cation exchange chromatography. The yield of $^{111}$In at EOB is $0.8mCi/{mu}\;Ahr$ and the nuclidic purity is over 99%. $^{111}In-DTPA\;and\;^{111}In-bleomycin$ were prepared for medical study.

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CdSe 박막반도체의 반송자 밀도 (Carrier Densities of CdSe Thin Films)

  • 김기원
    • 대한전자공학회논문지
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    • 제21권5호
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    • pp.7-10
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    • 1984
  • 일반적으로 단결정반도체시편에서는 그의 자유반송자 밀도값이 측정방법을 달리해도 일정하다. 그러나 CdSe 박막반도체의 자유반송자 밀도간은 측정방법을 달리했을 때 다르게 나타난다. 본 연구에서는 C-V방법, Seebeck 효과 및 a. c. Hall 효과를 통해서 측정한 CdSe 박막반도체의 자유반송자가 1018/㎤∼1024㎤범위의 값을 나타냈다. 이들 값의 차이를 나타내는 원인을 논의하고자 한다.

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The Mitochondrial Tricarboxylate Carrier of Silver Eel: Chemical Modification by Sulfhydryl Reagents

  • Capobianco, Loredana;Impagnatiello, Tecla;Ferramosca, Alessandra;Zara, Vincenzo
    • BMB Reports
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    • 제37권5호
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    • pp.515-521
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    • 2004
  • The tricarboxylate (or citrate) carrier was purified from eel liver mitochondria and functionally reconstituted into liposomes. Incubation of the proteoliposomes with various sulfhydryl reagents led to inhibition of the reconstituted citrate transport activity. Preincubation of the proteoliposomes with reversible SH reagents, such as mercurials and methanethiosulfonates, protected the eel liver tricarboxylate carrier against inactivation by the irreversible reagent N-(1-pyrenyl)maleimide (PM). Citrate and L-malate, two substrates of the tricarboxylate carrier, protected the protein against inactivation by sulfhydryl reagents and decreased the fluorescent PM bound to the purified protein. These results suggest that the eel liver tricarboxylate carrier requires a single population of free cysteine(s) in order to manifest catalytic activity. The reactive cysteine(s) is most probably located at or near the substrate binding site of the carrier protein.