• Title/Summary/Keyword: Pd/Co

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Improvement of $CO_2$Decomposition by Impregnating Noble Metals to Nano-size (Ni, Zn)-ferrites (귀금속 첨가에 의한 나노 (Ni, Zn)-페라이트의 $CO_2$분해 향상)

  • Kim, Jeong-Sik;An, Jeong-Ryul;Gang, Gye-Myeong
    • Korean Journal of Materials Research
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    • v.11 no.10
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    • pp.846-850
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    • 2001
  • In the present study, nano-size powders of ternary ferrites, $Ni_{0.5}Zn_{0.5}Fe_2O_4$, as the potential catalysts of $CO_2$decomposition, were prepared by the wet processing of hydrothermal synthesis and coprecipitation method, and the catalyzing effects of impregnation of the noble metals, Pt and Pd, onto $Ni_{0.5}Zn_{0.5}Fe_2O_4$for the $CO_2$decomposition were investigated. XRD results of the synthesized ferrites showed a typical spinel structure of ferrite and the particle size was very small as about 6~10 nm. BET surface area of the ternary ferrites was not affected by the impregnation of Pt and Pd. The reactivity of the $CO_2$decomposition to carbon was improved by the impregnation of the noble metals of Pd and Pt. The effect of Pd-impregnation on the $CO_2$decomposition rate was higher than Pt-impregnation.

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Effect of metal primers and tarnish treatment on bonding between dental alloys and veneer resin

  • Choo, Seung-Sik;Huh, Yoon-Hyuk;Cho, Lee-Ra;Park, Chan-Jin
    • The Journal of Advanced Prosthodontics
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    • v.7 no.5
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    • pp.392-399
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    • 2015
  • PURPOSE. The aim of this study was to evaluate the effect of metal primers on the bonding of dental alloys and veneer resin. Polyvinylpyrrolidone solution's tarnish effect on bonding strength was also investigated. MATERIALS AND METHODS. Disk-shape metal specimens (diameter 8 mm, thickness 1.5 mm) were made from 3 kinds of alloy (Co-Cr, Ti and Au-Ag-Pd alloy) and divided into 4 groups per each alloy. Half specimens (n=12 per group) in tarnished group were immersed into polyvinylpyrrolidone solution for 24 hours. In Co-Cr and Ti-alloy, Alloy Primer (MDP + VBATDT) and MAC-Bond II (MAC-10) were applied, while Alloy Primer and V-Primer (VBATDT) were applied to Au-Ag-Pd alloys. After surface treatment, veneering composite resin were applied and shear bond strength test were conducted. RESULTS. Alloy Primer showed higher shear bond strength than MAC-Bond II in Co-Cr alloys and Au-Ag-Pd alloy (P<.05). However, in Ti alloy, there was no significant difference between Alloy Primer and MAC-Bond II. Tarnished Co-Cr and Au-Ag-Pd alloy surfaces presented significantly decreased shear bond strength. CONCLUSION. Combined use of MDP and VBATDT were effective in bonding of the resin to Co-Cr and Au-Ag-Pd alloy. Tarnish using polyvinylpyrrolidone solution negatively affected on the bonding of veneer resin to Co-Cr and Au-Ag-Pd alloys.

Exchange Bias Perpendicular Magnetic Anisotropy and Thermal Stability of (Pd/Co)N/FeMn Multilayer ((Pd/Co)N/FeMn 다층막에서의 교환바이어스 수직자기이방성과 열적안정성)

  • Joo, Ho-Wan;An, Jin-Hee;Kim, Bo-Keun;Kim, Sun-Wook;Lee, Kee-Am;Lee, Sang-Suk;Hwang, Do-Geun
    • Journal of the Korean Magnetics Society
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    • v.14 no.4
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    • pp.127-130
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    • 2004
  • Magnetic properties and thermal stability by exchange biased perpendicular magnetic anisotropy in (Pd/Co)$_{N}$FeMn multilayer deposited by do magnetron sputtering system are investigated. We measured the perpendicular magnetization curves of (Pd(0.8nm)/Co(0.8nm)$_{5}$FeMn multilayer as function of FeMn thickness and annealing temperature. As FeMn thickness increases from 0 to 21nm, the perpendicular exchange bias(Hex) obtained 127 Oe at FeMn thickness 15nm. As the annealing temperature increases to 24$0^{\circ}C$, the E$_{ex}$ increased from 115 Oe to 190 Oe and disappeared exchange biased perpendicular magnetic anisotropy effect at 33$0^{\circ}C$.