• Korean Journal of Materials Research
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• v.24 no.1
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• pp.43-47
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• 2014

NiO-doped hibonite pigments were synthesized by the solid state method to get stabilized blue color pigment in both oxidation and reduction atmospheres. Optimum substitution condition with NiO for hibonite blue pigment was investigated. Experimental results were comparable to those of previous cobalt-minimization studies performed with other phosphate- or oxide-based cobalt-containing ceramic pigments (having olivine ($Co_2SiO_4$), spinel ($CoAl_2O_4$), or with co-doped willemite ($(Co,Zn)_2SiO_4$) structures). Composition was designed varying the NiO molar ratio increasing with $SnO_2$. The optimum substitution content is 0.93 mole NiO with 0.75mole $SnO_2$. The characteristics of the synthesized pigment were analyzed by XRD, Raman spectroscopy, SEM, and UV-vis. Synthesized pigment was applied to a lime-barium glaze with 10 wt% each and fired at an oxidation atmosphere of $1250^{\circ}C/1h$ and a reducing atmosphere $1240^{\circ}C/1h$. Blue color was obtained with $L^*a^*b^*$ values at 43.39, -6.78, -18.20 under a reducing atmosphere and 41.66, -6.36, -14.7 under and oxidation atmosphere, respectively.

• Journal of Magnetics
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• v.18 no.4
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• pp.428-431
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• 2013

We demonstrate that a partial loading of $Ni_{0.5}Zn_{0.5}Fe_2O_4$ (Ni-Zn ferrite) film remarkably improves impedance matching of electrically small $Ba_3Co_2Fe_{24}O_{41}$ ($Co_2Z$) hexaferrite antenna. A 3 ${\mu}m$ thick Ni-Zn ferrite film was deposited on a silicon wafer by the electrophoresis deposition process and post-annealed at $400^{\circ}C$. The fabricated Ni-Zn ferrite film has saturation magnetization of $268emu/cm^3$ and coercivity of 89 Oe. A partial loading of the Ni-Zn ferrite film on the $Co_2Z$ hexaferrite helical antenna increases antenna return loss to 24.7 dB from 9.0 dB of the $Co_2Z$ antenna. Experimental results show that impedance matching and maximum input power transmission to the antenna without additional matching elements can be realized, while keeping almost the same size as the $Co_2Z$ antenna size.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.303-307
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• 2008

$NiO,\;Cu_2O,\;Mn_2O_3$ and $Cr_2O_3$ as p-type semiconductors were added in CoO with 15 wt.% ethylene glycol binder and measured the butane gas sensing characteristics. The highest sensitivity is obtained for the NiO-CoO sensors. CoO-20 at.% NiO sensor with 15 wt.% ethylene glycol binder sintered at $1100^{\circ}C$ for 24 h exhibits high sensitivity of 90 % to 5000 ppm butane gas at the sensor temperature of $250^{\circ}C$, compared to low sensitivities at the low operating temperature for commercial sensors. Response and recovery times are, respectively, within few seconds and 1min in the static flow system, indicating rapid adsorption and desorption of butane gas on sensor surface even at this low temperature.

• Journal of the Korean Applied Science and Technology
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• v.24 no.4
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• pp.427-435
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• 2007

에너지원으로서 수소를 생산하기 위하여 하니컴 구조를 갖는 모노리스에 10 wt% $Ni/CeO_2-ZrO_2$ 촉매를 담지한 후 메탄의 수증기 개질 실험을 수행하였다. 다른 $CeO_2/ZrO_2$ 몰비를 갖는 촉매들 중에서, $Ni/CeO_2-ZrO_2(CeO_2/ZrO_2=4/1)$촉매가 $700-800^{\circ}C$에서 높은 메탄의 전환율을 보여 주었다. 10wt% $Ni/CeO_2-ZrO_2$ 촉매가 담지된 금속 모노리스 촉매체는 높은 열전도도와 비표면적들로 인하여 좋은 촉매 특성을 보여줌을 확인할 수 있었다. 또한, 금속모노리스 촉매체는 반응물에서 과다의 수증기에 의한 수소 수율에서 크게 영향을 받지 않음을 알 수 있었다. $GHSV=30,000h^{-1}$, 반응물 비$(H_2O/CH_4=3.0)$ 반응온도 $800^{\circ}C$에서 금속모노리스 촉매체는 98%이상의 메탄의 전환율을 보여주었다. 생성물 가스에서 $CO_2/CO$의 비는 수증기/메탄의 반응물비가 증가할수록 수성가스화 반응에 의하여 증가됨을 알 수 있었다.

• Resources Recycling
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• v.24 no.1
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• pp.35-42
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• 2015

To obtain the fundamental information on the dissolution of nickel into the slag in the pyrometallurgical processes for treatment of wasted PCB, the distribution ratios of nickel between CaO-$SiO_2-Al_2O_3$-MgO slag and copper-5 wt%Ni alloy were measured at 1623 K to 1823 K under a controlled $CO_2$-CO atmosphere. The distribution ratio of Ni increased linearly with increasing oxygen partial pressure. Therefore, the dissolution reaction of nickel into the slags could be described by the following equation; $$Ni(l)_{metal}+\frac{1}{2}O_2(g)NiO(l)_{slag}$$ The distribution ratio of Ni increased linearly with increasing content of basic oxides(CaO and MgO) in slag. However, the distribution ratio of Ni decreased linearly with increasing temperature. From these results, the empirical equation of distribution ratio of Ni was obtained by the following equation from the analysis of experimental conditions by multiple regression. $${\log}L_{Ni}=0.4000{\log}P_{O2}-5.1{\times}10^{-4}T+0.3375\(\frac{X_{CaO}+X_{MgO}}{X_{SiO2}}\)$$

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.285-291
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• 2004

As a part of assessment of the structural material for the molten salt handling system, corrosion behavior of Inconel 718, X-750, Haynes 75 and Haynes 263 alloys in the molten salt of LiCl-Li$_2$O-O$_2$was investigated in the range of temperature; $650^{\circ}C$, time; 24~168h, $Li_2O$; 3wt%, mixed gas; Ar~10%$O_2$. In the molten salt of LiCl-$Li_2O-O_2$, the order corrosion rate was Haynes 263 ＜ Haynes 75 ＜ Inconel X-750 ＜ Inconel 718. Haynes 263 alloy showed the highest corrosion resistance among the examined alloys. Corrosion products of alloys were as fellows: Haynes 75: $Cr_2O_4$, $NiFe_2O_4$, $LiNiO_2$, $Li_2NiFe_2O_4$, Inconel 718; $Cr_2O_4$, $NiFe_2O_4$, Haynes 263; $Li(Ni,Co)O_2$, $NiCr_2O_4$, $LiTiO_2$, Inconel X-750; $Cr_2O_3$, $NiFe_2O_4$,$FeNi_3$, (Al,Nb,Ti)$O_2$. Haynes 263 showed local corrosion behavior and Haynes 75, Inconel 718 and Inconel X-750 showed uniform corrosion behavior.

• Clean Technology
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• v.9 no.3
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• pp.125-132
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• 2003

Activity improvement of Ni metal catalysts for carbon dioxide reforming was studied using HY-zeolite as the main supporter. As the reaction temperature increased, $CH_4$ and $CO_2$ conversions increased, and conversions higher than 80% was obtained above $700^{\circ}C$. As the Ni loading increased, the catalyst activity increased, and the highest activity was shown for the Ni loading of 13wt%. The HY-zeolite support showed the highest intial conversions of $CH_4$ and $CO_2$, but it showed faster deactivation than a ${\gamma}-Al_2O_3$ support. Nevertheless, it maintained the $CH_4$conversion higher than 80% after 24 hr reaction. The effect of promoters such as Mg, Mn, K, and Ca was also studied. It was observed that the Mg promotor exhibited the highest catalyst activity and less deactivation compared with Mn, K and Ca. After 24hr reaction, The optimum Mg content was found to be 5wt%.

• Journal of the Korean Magnetics Society
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• v.7 no.1
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• pp.19-24
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• 1997

Composition and process conditions for low temperature sintered NiCuZn ferrites were investigated, so as to fabricate multilayered chip inductor. The$Fe_2O_3$ deficiency for low temperature sintering was decreased with NiO contents of NiCuZn ferrites. The permeability of NiCuZn ferrites can be controlled in the range of 12~562 with the variation of NiO and $Co_3O_4$ contents. The $Q_{max} $ frequency of NiCuZn ferrites was decreased from 50 MHz to 3 MHz linearly with permeability increase from 60 to 560. The relation between the $Q_{max}$ frequency(Y) and permeability(X) of NiCuZn ferrites was expressed with the following empirical equation, logY=4.2-1.4logX.

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.1
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• pp.24-34
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• 2003

For gaseous fuel combustion with inherent $CO_2$ capture and low NOx emission, chemical-looping combustion may yield great advantages for the savings of energy to $CO_2$ separation and suppressing the effect on environment, In chemical-looping combustor, fuel is oxidized by metal oxide medium in a reduction reactor. Reduced particles are transported to oxidation reactor and oxidized by air and recycled to reduction reactor. The fuel and the air are never mixed, and the gases from reduction reactor, $CO_2$ and $H_2O$, leave the system as separate stream. The $H_2O$ can be easily separated by condensation and pure $CO_2$ is obtained without any loss of energy for separation. In this study, five oxygen carrier particles such as NiO/bentonite, NiO/YSZ, $(NiO+Fe_2O_3)VYSZ$, $NiO/NiAl_2O_4$, and $Co_{\chi}O_y/CoAl_2O_4$ were examined &om the viewpoints of reaction kinetics, oxygen transfer capacity, and carbon deposition characteristics. Among five oxygen particles, NiO/YSZ particle is superior in reaction rate, oxygen carrier capacity, and carbon deposition to other particles. However, at high temperature ($>900^{\circ}C$), NiO/bentonite particle also shows enough reactivity and oxygen carrier capacity to be applied in a practical system.

• Journal of the Korean Electrochemical Society
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• v.16 no.2
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• pp.59-64
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• 2013

Using $Na_2CO_3$ and $MeSO_4$ (Me = Ni, Co and Mn) as starting materials, the precursor of $[Ni_{0.6}Co_{0.2}Mn_{0.2}]CO_3$ has been synthesized by carbonate co-precipitation. The precursor was mixed with $Li_2CO_3$, and calcined at 750, 850, and$950^{\circ}C$ in air. Effect of calcinations temperature on characteristics of $Li[Ni_{0.6}Co_{0.2}Mn_{0.2}]O_2$ cathode materials was investigated. The structure and characteristics of $Li[Ni_{0.6}Co_{0.2}Mn_{0.2}]O_2$ were determined by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and electrochemical measurements. The X-ray diffraction (XRD) results show that the intensity ratio of $I_{(003)}/I_{(104)}$ increased and the R-factor ratio decreased with the increase of calcinations temperature. And Scanning electron microscopy (SEM) result show that the primary particle size increased. Especially, the $Li[Ni_{0.6}Co_{0.2}Mn_{0.2}]O_2$ calcined at $950^{\circ}C$ for 24 H shows excellent electrochemical performances with reversible specific capacity of $165.3mAhg^{-1}$ [cut-off voltage 2.5~4.3 V, 0.1 C($17mAhg^{-1}$)] and good capacity retention of 95.4% after 50th charge/discharge cycles[cut-off voltage 2.5~4.3 V, 1 C($170mAhg^{-1}$)].