• Journal of Electrochemical Science and Technology
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• v.3 no.1
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• pp.50-56
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• 2012

Nickel modified NiOOH electrodes were used for the electrocatalytic oxidation of ethanol in alkaline solutions where the methods of cyclic voltammetry (CV) and chronoamperometry (CA) were employed. In CV studies, in the presence of ethanol, an increase in the current for the oxidation of nickel hydroxide is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of ethanol is being catalysed through mediated electron transfer across the nickel hydroxide layer comprising of nickel ions of various valence states. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of ethanol was found to be $1{\times}10^7cm^2s^{-1}$.

• Journal of the Korean institute of surface engineering
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• v.38 no.1
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• pp.14-20
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• 2005

The control of internal stress is extremely important in electroforming because of the deliberately low adhesion between the electro form and the mandrel. Excessive tensile or compressive stress can cause distortion, separation problem, curling, peeling or separation of electroform prematurely from the mandrel, buckling and blistering. Nickel sulfamate bath has been widely used in electroforming because of its low internal stress and moderate hardness. In this study, real-time stress sensor has been used for stress control in chloride-free nickel sulfamate bath for 400 mm x 300 mm x 500 ㎛ nickel electroform. It was found that compressive stress found at low current density indicated the contamination of electrolyte, which is very useful in procuring buckling and peeling of electroform. No compressive stress is allowed for plate electroform. The real-time stress can also be used for accurate stress control of nickel electroform. The tensile stress was found to be increased slightly with increase in nickel electroform thickness, i.e., from initial 1.47 ksi to 2.02 ksi at 320 ㎛.

• Journal of the Korean institute of surface engineering
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• v.15 no.1
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• pp.1-10
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• 1982

Electroless plating is the continious formation of metallic coatings from metal ions by che-mical reduction without the use of electrical current. This is, however, more expansive than the conventional electroplating but is often used because of certain adventage. Here, general description of past research on electroless nickel plating, especially about the merits of each research was given. Part(Ⅰ) is for the conposition of solution, pretreatment and facilities of electroless nickel plating.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.572-575
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• 1997

The embedded atom method based on density functional theory was developed as a new means for calculating ground state properties of realistic metal system by Murray S. Daw, Stephen M. Foiles and Michael I. Baskes. In the paper, we had corrected constitutive formulae and parameters on the nickel for the purpose of doing Embedded Atom Method analysis. And then we have computed the properties of the nickel on the fundamental scale of the atomic structure. In result, simulated ground state properties, such as the lattice constant, elastics constants and sublimation energy, show good agreement with Daw's simulation data and with experimental data.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2546-2548
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• 2007

• Current Photovoltaic Research
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• v.11 no.4
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• pp.103-107
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• 2023

A Nickel oxide (NiO_x) thin films were prepared via sol-gel process on a transparent conductive oxide glass substrate. The NiO_x thin films were spin-coated in ambient air and subsequently annealed for 30 minutes at temperatures ranging from 150℃ to 450℃. The structural and optical characteristics of the NiO_x thin films annealed at various temperatures were measured using X-ray diffraction, field emission scanning electron microscopy, and ultraviolet-visible spectroscopy. After optimizing the NiO_x coating conditions, perovskite solar cells were fabricated with p-i-n inverted structure, and its photovoltaic performance was evaluated. NiO_x thin films annealed at 350℃ exhibited the most favorable characteristics as a hole transport layer, resulting in the highest power conversion efficiency of 17.88 % when fabricating inverted perovskite solar cells using this film.

• Bulletin of the Korean Chemical Society
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• v.22 no.5
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• pp.523-526
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• 2001

• Journal of the Korean institute of surface engineering
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• v.21 no.2
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• pp.76-82
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• 1988

The bright nickel electroplatings were carried out the Watt bath containg a solobel saccharin as class I brightner and para substituted benzaldehydes as class II one. Extended Huckel MO calculation was done and polarization was measured to examine between $\pi$-electron density and the brightness. The correlation is also investigated between $\pi$-electron density of oxygen atom of aldehyde group and slope of polarization curve. As a result of the analysis of rate equation of nucleation, the surface energy of the deposited particle was obtained from the slope of the plot of $\ell$nI against 1/η2, and also the reat equation of nucleation found to influnced on the leveling on the basis of adsorption theory. We have proposed the general electroplating mechanism that is applied other to all other electroplating but nickel one. The above elucidated mechanism can be extended can be extended to the all electroplating other than bright nickel electroplating.

• The Journal of the Korean dental association
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• v.51 no.10
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• pp.551-555
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• 2013

The purpose of this study was to give a guideline for selecting the nickel-titanium (NiTi) file by review from many studies. Since the early 1990s, several instrument systems manufactured from NiTi have been introduced into endodontic practice. The specific design characteristics vary, such as tip shape and size, cross sectional view, helix angle, and pitch space. Some of the early systems have been removed from the market or play only minor roles; others are still widely used. New designs continually are produced, but the extent to which clinical outcomes will depend on design characteristics is difficult to forecast. In this study, I have reviewed the different design characteristics in respect of the safety and efficiency. With the review from many studies, I concluded that the clinicians must be understand the specific design characteristics for selecting the ideal NiTi rotary instruments.

• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.773-777
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• 2016

A betavoltaic battery was prepared using radioactive $^{63}Ni$ attached to a three-dimensional single trenched P-N absorber. The optimum thickness of a $^{63}Ni$ layer was determined to be approximately $2{\mu}m$, considering the minimum self-shielding effect of beta particles. Electroplating of radioactive $^{63}Ni$ on a nickel (Ni) foil was carried out at a current density of $20mA/cm^2$. The difference of the short-circuit currents ($I_{sc}$) between the pre- and post-deposition of $^{63}Ni$ (16.65 MBq) on the P-N junction was 5.03 nA, as obtained from the I-V characteristics. An improved design with a sandwich structure was provided for enhancing performance.