• 제목/요약/키워드: niobium

검색결과 193건 처리시간 0.033초

Radiation Damage Effects in $NB^+$ Implanted Sapphire After Annealing

  • Huang, N.K.;Naramoto, H.
    • 한국진공학회지
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    • 제7권s1호
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    • pp.78-84
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    • 1998
  • Niobium ions of 380 keV energy have been implanted at 300k in sapphire with a dose of $5\times10^{16}\textrm{ions/cm}^2$ and subsequently thermal annealed up to $1100^{\circ}C$ at reducing atmosphere. The behavior of the radiation damage produced by ion implantation followed by annealing is investigated using optical absorption technique and X-ray photoelectron spectroscopy(XPS). It is found that different defects annealed are dependent on the annealing temperature owing to different mechanisms which are proposed on the basis of the optical absorption measurement, and the implanted niobium in sapphire is in different local environments with different charge states after annealing, which are analyzed by XPS measurements.

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RSFQ DFFC Circuit Design for Use in ALU

  • Nam, Doo-Woo;Kim, Kyu-Tae;Kang, Joon-Hee
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2003년도 High Temperature Superconductivity Vol.XIII
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    • pp.50-50
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    • 2003
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Surface characteristics and osteoblastic cell response of alkali-and heat-treated titanium-8tantalum-3niobium alloy

  • Lee, Bo-Ah;Kang, Choong-Hee;Vang, Mong-Sook;Jung, Young-Suk;Piao, Xing Hui;Kim, Ok-Su;Chung, Hyun-Ju;Kim, Young-Joon
    • Journal of Periodontal and Implant Science
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    • 제42권6호
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    • pp.248-255
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    • 2012
  • Purpose: The aim of the present study was to evaluate the biological response of alkali- and heat-treated titanium-8tantalum-3niobium surfaces by cell proliferation and alkaline phosphatase (ALP) activity analysis. Methods: Commercial pure titanium (group cp-Ti) and alkali- and heat-treated titanium-8tantalum-3niobium (group AHT) disks were prepared. The surface properties were evaluated using scanning electron microscopy, energy dispersed spectroscopy and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy and a profilometer. The contact angle and surface energy were also analyzed. The biological response of fetal rat calvarial cells on group AHT was assessed by cell proliferation and ALP activity. Results: Group AHT showed a flake-like morphology microprofile and dense structure. XPS analysis of group AHT showed an increased amount of oxygen in the basic hydroxyl residue of titanium hydroxide groups compared with group cp-Ti. The surface roughness (Ra) measured by a profilometer showed no significant difference (P>0.05). Group AHT showed a lower contact angle and higher surface energy than group cp-Ti. Cell proliferation on group AHT surfaces was significantly higher than on group cp-Ti surfaces (P<0.05). In comparison to group cp-Ti, group AHT enhanced ALP activity (P<0.05). Conclusions: These results suggest that group AHT stimulates osteoblast differentiation.