• 제목/요약/키워드: strontium

검색결과 403건 처리시간 0.024초

모나자이트 중의 납 정량을 위한 신속한 EDTA 적정법 (A Simple EDTA Titration Method for the Determination of Lead in Monazite)

  • 이철;조원지
    • 대한화학회지
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    • 제13권4호
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    • pp.313-316
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    • 1969
  • 모나자이트 중의 납함량을 신속하고 간편하게 결정하는 방법을 기술하였다. 즉 모나자이트 시료를 황산에 녹여 200ml가 되겠끔 희석하였다. 스트론튬으로 납을 정량적으로 분리한 후 3N 수산화나트륨에 녹였다. 여분의 Zn-EDTA를 가한 다음 남은 아연 이온을 0.01M EDTA표준용액으로 적정하였으며 이때 가리움제 (masking agent)러서 시안화칼륨 및 아세틸 아세톤을 가하였고 pH 5에서 자이렌을 오렌지(Xylenol orange)를 지시약으로 사용하였다.

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Particle Growth in Oxalate Process I

  • Park, Zee-Hoon;Shin, Hyo-Soon;Lee, Byung-Kyo
    • The Korean Journal of Ceramics
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    • 제2권2호
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    • pp.63-69
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    • 1996
  • Barium titanyl oxalates, strontium titanyl oxalates and calcium zirconyl oxalates were prepared with variation of solution concentration and method of adding mixed metal ion solution into oxalic acid. Then they were aged in distilled water, ethanol or methanol, respectively. Barium titanyl oxalates and calcium zironyl oxalates were grown in water and strontium titanyl oxalates were groun in both water and methanol. They were supposed to be grown through the solutionl and reprecipitation mechanism. Nonuniform dispersion of particles in liquid phase is thought to cause abnormal particle growth.

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Pechini법에 의한 Y-doped SrTiO3 분말의 합성 (Synthesis and Characterization of Y-doped SrTiO3 Powder by Pechini Method)

  • 윤미영;송락현;신동열;황해진
    • 한국분말재료학회지
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    • 제17권1호
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    • pp.59-64
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    • 2010
  • 8 mol% Y-doped $SrTiO_3$ powder was synthesized by Pechini method from titanium isopropoxide, strontium nitrate, yttrium nitrate, citric acid and ethylene glycol. A $Y_2Ti_2O_7$ pyrochlore phase-free perovskite powder was obtained by calcining a polymeric resin, which was prepared from a precursor solution, at $500^{\circ}C$ in an air atmosphere. Low temperature calcination could lead to a fine-grained microstructure. In the case of a solid-state reaction, an extended heat-treatment at high temperature in a reduced atmosphere needed to obtain a single phase perovskite $SrTiO_3$.

Influence of the Precursor Solutions on the Properties of BST Thin Films

  • Kang, Seong-Jun;Joung, Yang-Hee
    • Journal of information and communication convergence engineering
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    • 제1권2호
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    • pp.70-73
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    • 2003
  • We have studied the effects of solvents and additives in the precursor solutions on the characteristics of barium strontium titanate (BST) thin films. The solution having two solvents, ie. acetic acid for barium acetate and strontium acetate and 2-methoxyethanol for titanium isopropoxide and also having an additive of ethylene glycol shows good stability and remains homogeneous even after a month of ageing. It produces excellent BST thin film without cracks. Dielectric constant, loss tangent at 10KHz and leakage current density at 3V of the BST (70/30) thin film made from this solution are 339, 0.052 and 13.3 ${\mu}\textrm{A}$/$\texmrm{cm}^2$, respectively.

$SrTiO_3$/유기물 복합재료의 유전특성에 실란 커플링 처리의 효과 (Effect of Silane Coupling Treatment on Dielectric Properties of Strontium Titanate/Organic Composite)

  • 김준영;김상현;유명재;이우성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.219-220
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    • 2007
  • 실란 커플링제 종류에 따른 $SrTiO_3$/유기물 복합재료의 유전특성에 미치는 영향을 조사하여 비교하였다. 실란 커플링제는 amino계, epoxy계, methacryloxy계, acryloxy계, vinyl계를 사용하였으며, tape casting 방법으로 제작한 복합체 필름을 vacuum lamination 공정을 통하여 기판을 만들어 유전특성을 측정하였다. 실란 괴플링제의 종류에 따라 유전특성은 상이한 결과를 나타냈으며, acryloxy계를 제외한 다른 커플링제를 처리한 복합재료는 유전상수와 유전손실이 감소하는 경향을 확인할 수 있었다. Acryloxy계 커플링제를 처리한 복합재료는 커플링제가 처리되지 않은 복합재료와 비교하여 유전상수가 6%정도 증가하였며, 유전손실은 25%정도 감소하였다.

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Investigation of Isotope Selective Characteristics of the Strontium Magneto-optical Trap by the Fluorescence Detection

  • Ko Kwang-Hoon;Jeong Do-Young;Lim Gwon;Kim Taek-Soo;Cha Yong Ho;Cha Hyung Ki;Lim You-Kyoung
    • Journal of the Optical Society of Korea
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    • 제9권3호
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    • pp.87-91
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    • 2005
  • The strontium magneto optical trap followed by a Zeeman slower has been demonstrated. The isotope selective characteristics of the trap have been investigated. The fluorescence spectrum of the MOT was compared with those of other high resolution spectroscopic methods. The red detuned deflection beam is also considered for a more selective spectrum.

Cesium and strontium recovery from LiCl-KCl eutectic salt using electrolysis with liquid cathode

  • Jang, Junhyuk;Lee, Minsoo;Kim, Gha-Young;Jeon, Sang-Chae
    • Nuclear Engineering and Technology
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    • 제54권10호
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    • pp.3957-3961
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    • 2022
  • Deposition behaviors of Sr and Cs in various liquid cathodes, such as Zn, Bi, Cd, and Pb, were examined to evaluate their recovery from LiCl-KCl eutectic salt. Cations in the salt were deposited on the liquid cathode, exhibiting potential of -1.8 to -2.1 V (vs. Ag/AgCl). Zn cathode had successful deposition of Sr and exhibited the highest recovery efficiency, up to 55%. Meanwhile, the other liquid cathodes showed low current efficiencies, below 18%, indicating LiCl-KCl salt decomposition. Sr was recovered from the Zn cathode as irregular rectangular SrZn13 particles. A negligible amount of Cs was deposited on the entire liquid cathode, indicating that Cs was hardly deposited on liquid cathodes. Based on these results, we propose that liquid Zn cathode can be used for cleaning Sr in LiCl-KCl salt.

Initial Release of Nuclides from Spent PWR Fuels

  • Kim, S. S.;K. S. Chun;Kim, Y. B.;Park, J. W.
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
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    • pp.238-244
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    • 2004
  • The relationship between the leaching and gap inventory of spent fuel has been studied. When a specimen of J44H08 spent PWR fuel with 38 GWD/MTU has been leached in the synthetic granitic groundwater in Ar atmosphere, the released fraction of cesium was increased rapidly up to 0.7% at around 500 days and stayed below 0.8% until 3 years. This 0.7% of cesium might be released from the gap in this fuel. The measurement of gap inventory with C15I08 spent PWR fuel, having 35 GWD/MTU and 0.22% of fission gas release, was also determined near 0.6% for the cesium, which is a similar fraction of cesium released from the leaching experiment with J44H08 fuel. Its gap inventories of strontium and iodine were about 0.03 and less than 0.2% respectively. Respective fractions of cesium and strontium in grain boundary of C15I08 were 0.78, 0.09%.

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