• Proceedings of the Korean Magnestics Society Conference
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• 1997.11a
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• pp.24-25
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• 1997

• Proceedings of the Korean Ceranic Society Conference
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• 2004.10a
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• pp.81.3-81.3
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• 2004

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.19-19
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• 1999

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.33-33
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• 1999

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1999.04a
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• pp.19-20
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.283.2-283
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• 2002

• Journal of the Korean Society for Heat Treatment
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• v.9 no.2
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• pp.130-138
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• 1996

It has been investigated that the ion nitriding effects of a STD61 steel in various time conditions of 3 to 9 hours, and the microstructure of compound and diffusion layers of the ion nitrided specimen for 6 hours and subsequently reheated for 1 hour at various temperatures of $400{\sim}800^{\circ}C$ As the nitriding time increased, the thickness of compound and diffusion layers was increased, but the hardness of surface was not considerably increased (Max Hv=1045 at 9hrs). Some of the nitrogen was denitrided out of the surfac and diffused into the core, and also the oxides ($Fe_3O_4$, $Fe_2O_3$) were formed on the surface of the specimen during reheating. The compound layer was partially decomposed at about $600^{\circ}C$ but the diffusion layer was increased up to $800^{\circ}C$. With increasing reheated temperture, the hardness of the surface was decreased, whereas the hardness depth of diffusion layer (0.25mm) was increased up to $600^{\circ}C$ more than that of ion nitrided (0.18mm). The blend-heat treated STD61 steel by ion nitriding is therefore expected to hold on the characteristics of ion nitriding up to $600^{\circ}C$.

• Journal of Magnetics
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• v.5 no.1
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• pp.23-25
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• 2000

We have investigated the effects of Ar and$O_2$-ion milling on the exchange coupling field ($H_{ex}$) and coercive field ($H_c$) at the interfaces between substrates and NiO/NiFe films, to understand the exchange biasing mechanism. The $O_2$-ion milling was successfully performed by means of the electron cyclotron resonance (ECR) process. We found that the local roughness gradient of the NiO surface increased by $O_2$-ion milling. The ratio of $H_{ex}/H_c$ increased from 0.87 to 1.77, whereas $H_c$ decreased by almost a half as a results of the ion milling. The decrease in $H_c$could be interpreted as due to the refinement of magnetic domain size, which arose from the increase of the local roughness gradient of the NiO surface. The decrease in low $H_c$, and increase in $H_{ex}$ in NiO spin valves by ECR-ion milling are in the right direction far use in magnetoresistance (MR) heads.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.512-515
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• 2008

The removal of iron from neodymium chloride solution was carried out by solvent extraction using Alamine 336 in kerosine. The effect of Alamine 336, hydrochloric acid and chloride ion concentrations on the extraction of Fe were studied. The results showed that Alamine 336 as an extractant for removal of iron was effective and the extraction percentage of iron was increased with increasing hydrochloric acid and chloride ion concentration in aqueous solution. The extraction of 99% of iron is attained at a ratio of A/O = 4 by distilled water. The stripping yield of iron from loaded Alamine 336 decreased with decreasing hydrochloric acid concentration in stripping solution.

• Journal of Convergence for Information Technology
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• v.11 no.2
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• pp.117-123
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• 2021

The effects of electrolyte concentration on the electrochemical properties of Fe4[Fe(CN6)]3(FeHCF) as a novel active material for the electrode of aqueous zinc-ion batteries was investigated. The electrochemical reactions and structural stability of the FeHCF electrode were significantly affected by the electrolyte concentration. In the electrolyte solutions of 1.0-7.0 mol dm-3, the charge-discharge capacities increased with increasing electrolyte concentration, however gradually decreased as the cycle progressed. On the other hand, in the 9.0 mol dm-3 electrolyte solution, the initial capacity was relatively small, however showed good cyclability. Additionally, the FeHCF electrode after five cycles in the former electrolyte solutions, had a change in crystal structure, whereas there was no change in the latter electrolyte solution. This suggests that the performance of the FeHCF electrode is greatly influenced by the hydration structure of zinc ions present in electrolyte solutions.