• Journal of the Korean Chemical Society
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• v.15 no.2
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• pp.55-63
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• 1971

In this study, several nickel catalysts for the steam-hydrocarbon reforming process were prepared from various nickel salt, magnesium oxide, alumina and kaolinite. The activity and strength of the catalysts were investigated. 1. The proper composition of the calcined catalysts are: NiO (5-15%)-MgO(10-20%)-$Al_2O_3$(10-40%)-Kaolinite(50-80%). 2. The admixed or cosedimented ingredients of the catalysts was pelletized and calcinated at 1000 or $1150^{\circ}C$. Calcination at $1150^{\circ}C$ for an hour was optimum. 3. The water to oil ratio (W/O) for reforming of hexane should be above 7 mole/mole. As the W/O increases, more carbon dioxide and hydrogen, but less carbon monoxide was produced. Also carbon deposition become lessen at higher W/O. 4. Maximum conversion had attained at about $850^{\circ}C$. As the reaction temperature increases, more carbon monoxide and hydrogen, but less carbon dioxide and lower hydrocarbon was produced. 5. The percent conversion at $850^{\circ}C$ was about 80%, using a catalyst which the nickel oxide content are 5%.

• Korean Journal of Materials Research
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• v.10 no.12
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• pp.831-837
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• 2000

To improve the catalytic activity of platinum on polymer electrolyte fuel cell(PEFC), platinum was alloyed with cobalt and nickel at various temperature. By XRD, it was observed the crystal structure of alloy catalysts were the ordered face centered cubic(f.c.c) due to the superlattice line at $33^{\circ}$. As heat-treatment temperature was increased, the particle size of alloys also were increased and the crystalline lattice parameters were decreased. According to the results from mass activity, specific activity and Tafel slope measured by cell performance test and cyclic voltammogram, the catalyst activities of alloys are higher than that pure platinum.

• Advances in environmental research
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• v.2 no.4
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• pp.309-321
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• 2013

High AA new high capacity sorbent for preconcentration and determination of nickel in environmental samples was synthesized. The sorbent was synthesized by copolymerization of allyl glaycidyl ether / imminodiacetic acid with N,N-dimethylacrylamide as functional monomers in the presence of N,N-bismethylenacryl amid as cross linker and characterized by Fourier transform infra red spectroscopy, elemental analysis, thermogravimetric analysis and scanning electron microscopy. A recovery of 93.6% was obtained for the metal ion with 0.1 M, sulfuric acid as the eluting agent. The sorption capacity of the functionalized sorbent was 55.9 $mgg^{-1}$. The equilibrium sorption data of Ni(II) on polymeric sorbent were analyzed using Langmuir, Freundlich, Temkin and Redlich.Peterson models. Based on equilibrium adsorption data the Langmuir, Freundlich and Temkin constants were determined 0.87 (L mg-1), 25.87 ($mgg^{-1}$) $(Lmg^{-1})^{1/n}$ and 171.4 ($Jmol^{-1}$) respectively at pH 4.5 and $20^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.210-210
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• 2000

Vertically well aligned multi-wall carbon nanotubes (CNT) were grown on nickel coated glass substrates by plasma enhanced hot filament chemical vapor deposition at low temperatures below 600$^{\circ}C$. Acetylene and ammonia gas were used as the carbon source and a catalyst. Effects of growth parameters such as pre-treatment of substrate, plasma intensity, filament current, imput gas flow rate, gas composition, substrate temperature and different substrates on the growth characteristics of CNT were systematically investigated. Figure 1 shows SEM image of CNT grown on Ni coated glass substrate. Diameter of nanotube was 30 to 100nm depending on the growth condition. The diameter of CNT decreased and density of CNT increased as NH3 etching time etching time increased. Plasma intensity was found to be the most critical parameter to determine the growth of CNT. CNT was not grown at the plasma intensity lower than 500V. Growth of CNT without filament current was observed. Raman spectroscopy showed the C-C tangential stretching mode at 1592 cm1 as well as D line at 1366 cm-1. From the microanalysis using HRTEM, nickel cap was observed on the top of the grown CNT and very thin carbon amorphous layer of 5nm was found on the nickel cap. Current-voltage characteristics using STM showed about 34nA of current at the applied voltage of 1 volt. Electron emission from the vertically well aligned CNT was obtained using phosphor anode with onset electric field of 1.5C/um.

• Korean Journal of Materials Research
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• v.16 no.10
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• pp.656-662
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• 2006

We fabricated thermal evaporated 10 nm-$Ni_xCo_{1-x}$ (x=0.2, 0.5 and 0.8) /(poly)Si films to form nanothick cobalt nickel composite silicides by a rapid thermal annealing at $700{\sim}1100^{\circ}C$ for 40 seconds. A field emission scanning electron microscope and a micro-Raman spectrometer were employed for microstructure and silicon residual stress characterization, respectively. We observed self-aligned micro-pinholes on single crystal silicon substrates silicidized at $1100^{\circ}C$. Raman silicon peak shift indicates that the residual tensile strain of $10^{-3}$ in single crystal silicon substrates existed after the silicide process. We propose thermal stress from silicide exothermic reaction and high temperature silicidation annealing may cause the pinholes. Those pinholes are expected to be avoided by lowering the silicidation temperature. Our results imply that we may use our newly proposed composite silicides to induce the appropriate strained layer in silicion substrates.

• Journal of Industrial Technology
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• v.42 no.1
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• pp.7-12
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• 2022

High nickel layered oxide cathodes are gaining increasing attention for lithium-ion batteries due to their higher energy density and lower cost compared to LiCoO₂. However, they suffer from the formation of residual lithium on the surface in the form of LiOH and Li₂CO₃ on exposure to ambient air. The residual lithium causes notorious issues, such as slurry gelation during electrode preparation and gas evolution during cell cycling. In this review, we investigate the residual lithium issues through its impact on cathode slurry instability based on deformed polyvinylidene fluoride (PVdF) as well as its formation and reduction mechanism in terms of inherently off-stoichiometric synthesis of high nickel cathodes. Additionally, new analysis method with anhydrous methanol was introduced to exclude Li⁺/H⁺ exchange effect during sample preparation with distilled water. We hope that this review would contribute to encouraging the academic efforts to consider practical aspects and mitigation in global high-energy-density lithium-ion battery manufacturers.

• Korea Trade Review
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• v.47 no.4
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• pp.177-195
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• 2022

This study analyzed the volatility spillover effect between international non-ferrous metal futures markets using the BEKK-GARCH model. Statistical data are futures price data of copper (CU), aluminum (AL), nickel (NI), tin (SN) from Shanghai Futures Exchange (SHFE) and London Metal Exchange (LME) from April 1, 2015 to December 31, 2021. Combining the research results, first, in the case of copper, aluminum, and nickel, it was found that there was a two-way volatility spillover effect between the Shanghai and London markets, and the international influence of the London market was greater. Second, in the case of the tin, it was found that the Shanghai market has a volatility spillover effect on the London market from stage I, and it is strengthened in stage II. Third, in the case of nickel, it was found that there was a two-way volatility spillover effect in the first stage, but in the second stage, the London market had a unidirectional volatility spillover effect with respect to the Shanghai market. This study confirmed that China's influence in the international non-ferrous metal futures market is gradually increasing. In addition, it suggested that international investors can engage in arbitrage and hedging using China's non-ferrous metal futures market.

• Journal of the Korean Chemical Society
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• v.37 no.2
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• pp.206-212
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• 1993

Syntheses and properties of zwitterionic dithiocarbamates and their nickel(Ⅱ) complexes are described. The complexes have been characterized by mass infrared and electronic absorption spectroscopy, and conductivity measurement. Ni(Ⅱ)-dithiocarbamato complexes are soluble in polar solvents such as water, methanol, and acetone etc. The possible structures were proposed on the basis of elemental analyses and physical properties.

• Membrane and Water Treatment
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• v.1 no.1
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• pp.39-47
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• 2010

Using a conventional two-compartment cell with stirrers the separation of an aqueous solution of HCl-$NiCl_2$ by an anion-exchange membrane Neosepta-AFN was investigated. The dialysis process was characterized by the permeability coefficient of the membrane towards to $Cl^-$ ions. This quantity was determined by the numerical integration of equations, which describe the time dependence of the total concentration of $Cl^-$ ions in compartment initially filled with stripping agent (water), combined with an optimizing procedure. The analysis of the experimental results showed that this permeability coefficient is a satisfactory characteristic for the process studied. It can be graphically correlated with the initial acid and initial salt concentrations in the compartment initially filled with acid+salt mixture.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.2
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• pp.1-5
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• 2010

According to the high demand of hybrid components, the hybrid materials development and processing technology were increased in the industry field. Although hybrid materials have various machining technologies, the research about them has rarely been proceed. This study is to carry out results about design technology of miniaturized high-speed air spindle and machining characteristics of hybrid materials using that. We studied machining characteristics in Nickel-Chrome alloy(Ni-Cr) according to change rotating speed using miniaturized high-speed air spindle. As the following results, the change of surface shape and roughness was investigated as the processing conditions such as rotating speed of miniaturized high-speed air spindle.