• Title/Summary/Keyword: Nb

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Development of CCFL with Nb/Ni Gad Electrode for high efficiency (Nb/Ni Clad 전극을 이용한 고효율 CCFL 개발)

  • Park, Ki-Duck;Yang, Seong-Su;Park, Doo-Sung;Kim, Seo-Yoon;Lim, Young-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.441-443
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    • 2005
  • According as CCFL(Cold Cathode Fluorescent lamp) of light source in Backlight unit for Note PC (Personal computer) is presently needed to low power consumption and long life time, the development focus of CCFL is going on the discharge gas, phosphor and electrode material. First of all, discharge voltage characteristic of CCFL is closely connected with electrode material For low discharge voltage, the characteristic of electrode material is needed to low work function, low sputtering ratio and superior manufacturing property. We developed new CCFL with Nb/Ni Clad electrode superior to conventional CCFL. Because Nb/Ni Clad electrode with Ni material and Nb material, the electrical characteristic is superior to other electrode materials. The electrode of Nb/Ni Clad is composed that Ni of outside material has superior manufacturing property and Nb of inside material has low work function. Nb/Ni Clad of new electrode material is made by process of Rolling mill at high pressure and heat treatment. We compared electrical characteristic of Nb/Ni clad electrode with conventional Mo electrode by measurement. Mo electrode and Nb/Ni Clad electrode of cup type with diameter 1.1 mm and length 3.0mm are used to this experiment. Material content of Mo electrode is Mo 100%. But, Nb/Ni Clad electrode is composed by content of Nb 40% and Ni 60%. The result of comparison measurement between new CCFL with Nb/Ni Clad electrode and conventional CCFL was appeared that CCFL with Nb/Ni Clad electrode had superior characteristic than conventional CCFL. As a result of experiment, we completed Note PC with low power consumption and long life time by application of new CCFL with Nb/Ni Clad electrode.

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Measurement of $^{93}Nb(n,n{\alpha})^{89m}Y$, $^{93}Nb(n,{\alpha})^{90m}Y$ and $^{93}Nb(n,2n)^{92m}Nb$ Cross Sections for 14 MeV Neutrons ($^{93}Nb(n,n{\alpha})^{89m}Y$, $^{93}Nb(n,{\alpha})^{90m}Y$$^{93}Nb(n,2n)^{92m}Nb$ 반응의 14 MeV 중성자 반응 단면적 측정)

  • Kim, Y.S.;Kim, N.B.;Chung, K.H.;Bak, H.I.
    • Nuclear Engineering and Technology
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    • v.18 no.2
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    • pp.92-96
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    • 1986
  • The $^{93}Nb(n,n\alpha)^{89m}Y$, $^{93}Nb(n,{\alpha})^{90m}Y$ and $^{93}Nb(n,2n)^{92m}Nb$ cross sections at a neutron energy of 14.6 MeV have been measured relative to the $^{27}Al(n,p)^{27}Mg$ and $^{27}Al(n,{\alpha})^{24}Na$ cross sections. A small accelerator utilizing $T(D,n)^4He$ reaction was used as a neutron source and the neutron energy spread is about 0.4MeV at the sample. All induced activities were measured with a 70cc HPGe detector in the same geometry.

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Effects of V on the Formation of Ti-Nb-V Cabonitrides and Mechanical Properties in Low Carbon HSLA Steels (저탄소.저합금강의 Ti-Nb-V 복합 탄질화물 형성 및 기계적 특성에 미치는 V 첨가의 효과)

  • Kang, J.S.;Kim, D.J.;Park, C.G.
    • Transactions of Materials Processing
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    • v.15 no.8 s.89
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    • pp.581-585
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    • 2006
  • Effects of V on both the formation of Ti-Nb-V carbonitrides and mechanical properties of Ti-Nb bearing low carbon HSLA steels were investigated. Hot rolling process was simulated by using Gleeble 3500 system with the steels containing three different levels of V ($0{\sim}0.1wt.%$). Vanadium precipitated as Ti-Nb-V carbonitrides at austenite region but it did not precipitate as VC during austenite to acicular ferrite or bainitic ferrite phase transformation. As V content increased, the amount of Nb precipitates was decreased but the average size of Ti-Nb-V carbonitrides was increased due to larger diffusivity of V than that of Nb. Coarsened Ti-Nb-V carbonitrides could act as heterogeneous nucleation site during ${\gamma}{\rightarrow}{\alpha}$ phase transformation, thus, acicular ferrite transformation was promoted as V content increased, resulting in increase of upper shelf energy.

Effect of Metallic Tungsten Concentration on Resistance Switching Behavior of Sputtered W-doped NbOx Films

  • Lee, Gyu-Min;Kim, Jong-Gi;Na, Hui-Do;Son, Hyeon-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.288-288
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    • 2012
  • In this study, we investigated that the resistance switching characteristics of W-doped NbOx films with increasing W doping concentration. The W-doped NbOx based ReRAM devices with a TiN/W-doped NbOx/Pt/Ti/SiO2 were fabricated on Si substrates. The 50 nm thick W-doped NbOx films were deposited by reactive dc magnetron co-sputtering at $400^{\circ}C$ and oxygen partial pressure of 35%. Micro-structure of W-doped NbOx films and atomic concentration were investigated by XRD, TEM and XPS, respectively. The W-doped NbOx films showed set/reset resistance switching behavior at various W doping concentrations. The process voltage of set/reset is decreased and whereas the initial current level is increased with increasing W doping concentration in NbOx films. The change of resistance switching behavior depending on doping concentration was discussed in terms of concentration of metallic tungsten of oxygen of W-doped NbOx.

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Germination and Seedling Growth Response of Sprouts and Leafy Vegetables after Applying Oxygen Nanobubble Water

  • Lee, Seo Youn;Jung, Seo Hee;Cho, Ah Ram;Shim, Myung Syun;Chung, You Kyung;Kim, Yoon Jin
    • Journal of People, Plants, and Environment
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    • v.24 no.6
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    • pp.609-617
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    • 2021
  • Background and objective: The nanobubbles remain stable in water, and it increased dissolved oxygen (DO) in the water that promotes the seed germination and the plant growth. We evaluated the seed germination and growth of sprouts (radish, wheat, and barley) and leafy vegetables (red mustard and pak choi) when irrigated with various DO of nanobubble water (NB). Methods: The oxygen NB was generated by surface friction and treated in 4 levels: NB 0% (control, DO 9.21 mg·L-1), NB 20% (DO 15.40 mg·L-1), NB 33% (DO 20.93 mg·L-1), and NB 100% (DO 39.29 mg·L-1). Results: The root length of radish and wheat increased more in NB 33% than the control plot. The fresh weight increased in NB 33% compared to the control plot in radish and wheat, and both fresh and dry weight increased more in NB 20%, NB 33%, and NB 100% than the control plot of barley. The leaf length and width of red mustard decreased more in NB 33% and NB 100% than the control plot and NB 20%, which indicated the leaf compactness. The fresh and dry weight of shoot and root increased more in NB 100% than the control plot in red mustard. In pak choi, the shoot fresh weight increased more in NB 100% than the control plot. In leafy vegetables, the germination rate of red mustard in NB 100% was higher than the control plot, however, it was not significantly different between oxygen NB plots in sprout vegetables. Conclusion: The results showed that the root growth and biomass increased after applying NB 33% in sprout vegetables. The leaf growth properties as the number of leaves and leaf size were not significantly different or decreased in NB treatments compared to control plots, but NB 100% (DO 39.29 mg·L-1) effectively increased the root growth and plant biomass in leafy vegetables.

Electrochemical Corrosion Properties of Amorphous Co-Nb-B Alloys Prepared by Melt-Spinning Method (액체급냉법에 의해 제조한 비정질 Co-Nb-B 합금의 전기화학적 부식 특성)

  • Kim, Eun-Sun;Kim, Hyun-Goo;Jang, HeeJin
    • Corrosion Science and Technology
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    • v.13 no.4
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    • pp.152-156
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    • 2014
  • This study was undertaken to examine the electrochemical corrosion properties of an $Co_{80}Nb_{10}B_{10}$ and $Co_{82}Nb_8B_{10}$ amorphous alloys prepared by melt-spinning method under various conditions. The potentiodynamic polarization responses at various levels of pH (pH 2, pH 7, pH 12) showed that the corrosion current rate of $Co_{80}Nb_{10}B_{10}$ alloy is lower than that of $Co_{82}Nb_8B_{10}$ alloy in all levels of pH, implying the general corrosion resistance of the alloy with higher Nb content is better than that with higher Co content. The pitting potential of $Co_{80}Nb_{10}B_{10}$ alloy was also better than that of $Co_{82}Nb_8B_{10}$, evidenced by the higher pitting potential. Nb is thought to be effective in increasing the protectiveness of the passive film and hence to improve the corrosion resistance of Co-Nb-B alloys.

Optical Characterizations of $LiNbO_{3}$ Single Crystals Doped with $MgO/TiO_{2}$

  • You-song Kim
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.1 no.1
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    • pp.1-4
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    • 1991
  • The applicability of $LiNbO_{3}$ as a substrate for fabrication of Ti-indiffused waveguide electro-optic devices is limited. Ti diffuses comparatively in congruently melting $LiNbO_{3}$; the Curie temperature of this material is too low to permit diffusion temperatures much above $1100^{\circ}C$ without the necessity of re-poling the crystal. Both of hese difficulties could be eliminated by incorporating certain dopants in $LiNbO_{3}$. Crystals of $LiNbO_{3}$ doped with Ti and Mg were grown and evaluated. The electroptic coefficients and birefringence of $LiNbO_{3}$ doped crystals were measured at ${\lambda}=.6328$ and $1.32\;$\mu{m}$. Curie temperatures were measured. The Curie temperature of both undoped and Ti-doped $LiNbO_{3}$ was $1130^{\circ}C$; that for Mg-doped $LiNbO_{3}$ was $30^{\circ}$ higher. From these data, a composition for the crystals was estimated. Thermogravimetric data confirmed this estimate and showed that the composition of Mg : $LiNbO_{3}$ was $49.3{\pm}0.2mole%\;Li_{2}O$ ; the composition of the undoped and Ti : $LiNbO_{3}$ samples was $48.6{\pm}0.2mole%$. Diffusion of Ti into both Mg-doped and Ti-doped $LiNbO_{3}$ crystals was studied as a function of $Li/NbO_{3}$ ratio and temperature.

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A study on corrosion resistance of Ti-Nb alloys by Nb contents (Nb 함량에 따른 Ti-Nb계 합금의 내식성에 대한 연구)

  • Park, Geun-Hyeung
    • Journal of Technologic Dentistry
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    • v.28 no.1
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    • pp.61-66
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    • 2006
  • Titanium alloys have been used for dental materials due to it's very good biocompatibility. Ti-6Al-4V alloy instead of pure titanium is being widely used as biomaterials has some characteristics such as high fatigue strength, tensile strength and corrosion resistance. But it has been reported recently that the vanadium element expresses cytotoxicity and carcinogenicity and the aluminium element is related with dementia of Alzheimer type and neurotoxicity. The Ti-Nb alloys has designed and examined corrosion resistance. Ti-3wt.%Nb($\alpha$type), Ti-20wt.%Nb(${\alpha}+{\beta}$type) and Ti-40wt.%Nb($\beta$type) alloys were melted by vacuum arc furnace. The corrosion resistance of Ti alloys was evaluated by potentiodynamic polarization test in the solution of 0.9% NaCl and 5% HCl. The results can be summarized as follows: 1) For the corrosion test in the solution of 0.9% NaCl and 5% HCl, the corrosion behaviour of Ti-Nb alloys was similar to ASTM grade 2 CP Ti. 2) The corrosion resistance of Ti-20Nb alloy was better than that of CP-Ti, Ti-3Nb, Ti-40Nb alloy in 0.9% NaCl and 5% HCl, solutions.

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The Structural properties of $BaTiO_3+Nb_2O_5$ ceramics with sintering temperature (소결온도에 따른 $BaTiO_3+Nb_2O_5$ 세라믹스 구조적 특성)

  • Lee, Sang-Chul;Kim, Ji-Heon;Kim, Kang;Ryu, Ki-Won;Lee, Young-Hie
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.05c
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    • pp.127-130
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    • 2001
  • The $BaTiO_3+xNb_2O_5$(x=6, 8, 10wt%) ceramics were prepared by conventional mixed oxide method. The structural properties of the $BaTiO_3+Nb_2O_5$ ceramics with the sintering temperature and addition of $Nb_2O_5$ were investigated by XRD and SEM. Increasing the sintering temperature, the $2{\theta}$ value of BT(110) peak was shifted to the lower degree and intensity of the $Ba_6Ti_2Nb_8O_{30}$ (133) peak was increased. Increasing the addition of $Nb_2O_5$, the intensity of $BaTiNb_4O_{13}$ (201) peak was decreased and $Ba_6Ti_2Nb_8O_{30}$ (133) peak was increased. The grain size of the $BaTiO_3+Nb_2O_5$ ceramics sintered at $1500^{\circ}C$ were almost uniform.

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