• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.5
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• pp.1-11
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• 2008

This study was carried out to provide primary data set for cleaning of contamination site. By having hydroponic culture on Salix alba and S. caprea seedling treated with Ni solution, the result of Ni accumulation came out as followings : In a treatment of Ni to the Salix alba and S. caprea, Ni accumulation increased in its root, leaves, and stem, as Ni concentration became higher until $10.0{\mu}mol$. But in a $100.0{\mu}mol$ treatment, the seedlings died after 4 weeks. Ni accumulation in the Salix alba and S. caprea was the highest in its roots, second-highest in leaves, and the lowest in stems. In the case of $10.0{\mu}mol$ treatment of Ni solution, Ni accumulation in roots were above 500.0mg/L, and leaves were above 20.0mg/L. But it was lower than 13.0mg/L in stems. Ni accumulation in the plant increased more when nutrient solution containing Ni was weekly changed than just refilling the same amount of nutrient solution that evaporated Ni accumulation in Salix alba was higher than S. caprea when the nutrient solution had been refilled only.

• Journal of Magnetics
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• v.6 no.4
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• pp.145-147
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• 2001

The effect of interface roughness between [Ni/Mn] superlattice and pinned NiFe layer on magnetoresistance (MR) of [Ni/Mn] superlattice-based spin valve films was investigated. Antiferromagnetic phase structure and interface roughness of [Ni/Mn] superlattice spin valve films were compared in the as-deposited and the annealed samples at 240$\^{C}$, respectively. Surface morphology of spin valves was substantially flattened due to the formation of the antiferromatic NiMn phase. In case of Co insertion between Cu and NiFe, the interlace roughness and MR ratio in the annealed [NiMn] superlattice and pinned NiFe/Co layer increased more than those in the annealed [Ni/Mn] superlattice and pinned NiFe layers respectively.

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.1
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• pp.78-90
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• 2012

To understand the electronic structure of $[NiS_4]^-$ complex ions, two complexes with such $[NiS_4]^-$ core, $FcCH=CHPymCH_3[Ni(dmit)_2]$ (Pym = pyridinium, $dmit^{2-}$ = 2-thioxo-1,3-dithiole-4,5-dithiolate) and $FcCH=CHPymCH_3[Ni(dddt)_2]{\cdot}{\frac{1}{2}}H_2O$ ($dddt^{2-}=5,6-dihydro-1,4-dithiin-2,3-dithiolato$), were synthesized to be characterized by X-ray crystallography, single crystal electron paramagnetic resonance (EPR) and density functional theory (DFT) calculation. Powder EPR spectra show narrow g-anisotropy but the anisotropy is bigger in $[Ni(dmit)_2]^-$ than in $[Ni(dddt)_2]^-$, indicating bigger spin density in Ni(III) d-orbital of $[Ni(dmit)_2]^-$ than in $[Ni(dddt)_2]^-$, which is consistent to DFT results. EPR studies of the crystals of the complexes surprisingly suggest that the $g_y$-axis of $[Ni(dddt)_2]^-$ is approximately on or perpendicular to the $[NiS_4]^-$ plane while the $g_y$-axis of $[Ni(dmit)_2]^-$ is on the plane, though DFT study of the complexes of this study and previously reported $[NiS_4]^-$ complexes indicate that the $g_y$-axis is on the $[NiS_4]^-$ plane.

• Progress in Superconductivity
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• v.1 no.1
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• pp.51-55
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• 1999

A Ni/Ag/Stainless steel 310S(SS310S) multi-layer sheet has been fabricated by a combination of vacuum brazing, cold rolling and texture annealing processes. After heat-treating the thin Ni/Ag/SS310S multi-layer sheet at $900^{\circ}C$ for 2h, development of (100)<001>cube texture on Ni surface was revealed by (111) pole figure. Quantitative chemical analysis was made by EPMA for the cross-section of the Ni/Ag/SS310S multi-layer sheet. EPMA results showed that Ag diffusion into the Ni layer, which may suppress the cube texture development, was negligible. A small amount of Cr atoms were detected in the Ni layer. It showed that Ag can be used as a chemical barrier of alloying element atoms in Ni layer for the Ni/Ag/SS310S multi-layer sheet and a strong cube texture was developed for the Ni layer in the Ni/Ag/SS310S multi-layer sheet.

• Korean Journal of Materials Research
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• v.13 no.1
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• pp.6-10
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• 2003

Electroplated Ni and Ni-W micro-molds using LIGA-like process for replication of micro-components such as microfluidic parts and micro optical parts have been investigated. In general, it is hard to produce micro-parts using conventional mechanical processes. Micro-mold formed by LIGA-like process could fabricate micro-parts with high aspect ratio. In this paper, fabrication and properties of electroplated Ni molds with varying applied current types as well as those of Ni-W molds were investigated. Ni molds fabricated under pulse-reverse current showed the highest hardness value of about 160 Hv. Ni-W molds showed the hardness of about 500 Hv which was much harder than that of Ni electroplated molds. The above results suggested that high quality micro-molds could be fabricated by using Ni electroplating of pulse-reverse type for core molds and sequential Ni-W alloys coating.

• Journal of Welding and Joining
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• v.30 no.6
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• pp.106-112
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• 2012

This study was carried out to investigate the effect of bonding temperature and holding time on microstructure and mechanical properties in brazing joints of Ni-base superalloy using MBF-30 (Ni-4.5Si-3.2B [wt.%]). The heating rate was $20^{\circ}C$/min to the bonding temperatures $1050^{\circ}C$, $1070^{\circ}C$, $1090^{\circ}C$ under high vacuum condition. The holding times were 100s, 400s, 900s and 1600s. $Ni_3B$ phases and proeutectic Ni were observed in the interlayer of Ni-201. Then, Ni3B and Ni3Si were found in the middle region of brazing joint. Cr-boride phase appeared in the interlayer of Inconel-625. Tensile strength and elongation were decreased at $1050^{\circ}C$-1600s, $1070^{\circ}C$-900s and $1090^{\circ}C$-400s. After observation the fracture specimens, There was Ni3B which is very brittle phase in the grain boundary of Ni201.

• Proceedings of the Korean Magnestics Society Conference
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• 1997.11a
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• pp.28-29
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• 1997

• Journal of the Korean Magnetics Society
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• v.5 no.6
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• pp.963-967
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• 1995

Ultra thin layers of NiFeCo or NiFe were inserted at the interfaces of Ni and Cu to form a multilayer structure. In case of inserting a NiFe layer, the magnetoresistance was about 6%, the saturation magnetic field was 50 Oe and the hysteresis of R-H (resistance-magnetic field) was very small. In case of inserting a NiFeCo layer, the magnetoresistance increased to about 7% but the saturation magnetic field and hysteresis were also increased. The increase of the output under biased magnetic field was much larger in case of inserting a NiFe layer because of relatively smaller hysteresis in R-H behavior.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.2993-2999
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• 2015

Steel companies are applying Ni-B or Ni-Co alloy plating to protect the surface of Continuous casting mold, and they are using saccharin polish which causes crack on plating layer due to sulfur in saccharin. It is considered that the Ni-S compound causes the cracking and additional tensile stresses. The Ni-Mn-B ternary alloy plating was developed for suppression of crack by forming Mn-S compound before Ni-S compound is formed, but there were no domestic or international standard on the Ni-Mn-B alloy plating. Therefore, reliability evaluation standard was established to evaluate the newly developed Ni-Mn-B plating. To develop accelerating life testing method, FMEA(Failure Mode & Effective analysis) was used to analyze the cause of the main failure in plating. The Ni-Mn-B reliability standard included accelerating life test method, and it was categorized by the fundamental performance test, environment test, and accelerated life test, and was designed to guarantee 1 000 hours of B10 life with 80 % reliable level.

• Journal of Welding and Joining
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• v.13 no.4
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• pp.147-154
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• 1995

In order to study the bonding mechanism of Ni/B/Ni transient liquid phase bonding system, width of liquid layers were calculated, where in this system melting point of insert material(B) is higher than bonding temperature and melting point of base metal(Ni). Caclulated values were compared with experimental ones which were measured by bonding Ni/B/Ni system at 1433-1474K under vacuum atmosphere. As results, the width of initial liquid layer of Ni/B/Ni system was calculated as $W_{IL}$ = $W_{o}$[1 + {2.100..rho.$_{S/}$ ( $X_{3}$ + $X_{4}$)..rho.$_{Ni}$ }-.rho.$_{S/}$.rho. Ni/], and it was nearly same with experimental values. Maximum width of liquid layer, width of liquid layer during isothermal solidification and isothermal solidification time were calculated also.o.o.o.