• Title/Summary/Keyword: Nickel (Ni)

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Preparation of Nickel Powders by the Reduction of Ni(OH)2 Reactant Slurries from Nonaqueous Media (비수용성 매질로부터 Ni(OH)2 반응슬러리의 환원반응에 의한 니켈 분말의 제조)

  • Choi Eun Young;Lee Yoon Bok;Yoon Suk Young;Kim Kwang Ho;Kim Jin Chun;Rhyim Young Mok;Kim Hyong Kuk;Kim Yang Do
    • Korean Journal of Materials Research
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    • v.15 no.5
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    • pp.334-339
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    • 2005
  • Nickel Powders were synthesized by the reduction of $Ni(OH)_2$ reactant slurries from nonaqueous media, and the morphological characteristics of nickel powders with the addition of NaOH, the composition of mixed solvents, reaction temperature and reaction time were investigated. The NaOH addition changed the structure of agglomeration in the submicron range. As the volume ratio of TEA to DEA increased, the powders slightly suppressed the agglomeration between particles and their size increased. The reaction temperature on size and shape of nickel powders was significant. As reaction time was shortened from 40 min to 0.3 min at $220^{\circ}C$, size distribution of nickel powders was transferred to a narrow size distribution owing to the presence of smaller particles with below $1.0\;{\mu}m$.

Histological Indicator Change of the Abalone, Haliotis discus hannai Exposed to Nickel Chloride (NiCl2) (염화니켈 (NiCl2) 노출에 따른 북방전복, Haliotis discus hannai의 조직학적 지표 변화)

  • Kim, Suji;Jeon, Mi Ae;Ju, Sun Mi;Kim, Jae Won;Kang, Ju-Chan;Lee, Jung Sick
    • The Korean Journal of Malacology
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    • v.31 no.2
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    • pp.143-150
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    • 2015
  • This study was conducted to find out accumulated concentration of nickel, survival rate and falling rate, structural changes of abalone, Haliotis discus hannai exposed to nickel chloride. Experimental groups were composed of one control condition and five nickel chloride exposure conditions (5.9, 8.8, 13.3, 20.0, 30.0 mg/L). The accumulation of nickel in abalone was significantly increased all exposure group. Though the exposure groups had lower survival rate than the control group, higher falling rate than the control group. Histopathological changes in the foot, gill and hepatopancreas of abalone revealed obvious with exposure group than control group.

Research Trends in Coating Strategies for Residual Lithium Control in High-Nickel Li(NixCoyMn1-x-y)O2 Cathodes (고니켈 삼원계 층상구조 양극 물질의 잔류 리튬 제어를 위한 코팅 기술 연구 동향)

  • Ui Yeoun Song;Eun Ji Lee;Ji Eun Lee
    • Applied Chemistry for Engineering
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    • v.35 no.3
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    • pp.182-191
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    • 2024
  • Li(NixCoyMn1-x-y)O2 (NCM) is the intensively developed cathode material for expanding the electric vehicle market and developing lithium-ion batteries that meet higher capacity, longer life, and lower cost. High-nickel NCM increases the nickel content to 80% or more, securing price competitiveness by improving performance with high energy density and reducing the cost of cobalt. However, the high-nickel NCM materials have a residual lithium problem, leading to issues in battery performance degradation and stability. While various methods exist for removing residual lithium, such as washing, doping, and coating, this paper focuses on recent research trends in coatings aimed at enhancing NCM performance and stability by removing residual lithium.

Catalytic Hydrogenation of Triglyceride in a Semi-batch Reactor (Semi-batch 반응기에서의 트리글리세라이드 접촉 수소화 반응)

  • An, Jae-Yong;Lee, Choul-Ho;Jeon, Jong-Ki
    • Clean Technology
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    • v.25 no.2
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    • pp.101-106
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    • 2019
  • The aim of this study is to investigate the feasibility of an Ni-SA catalyst, which was prepared from nickel, kieselguhr, and alumina, for the hydrogenation of triglyceride in a bench-scale reactor. Ni-SA powders were prepared by precipitating nickel precursors on a silica and alumina support. The powder was reduced in a hydrogen flow, mixed with a saturated palm oil, and then cooled to prepare an Ni-SA catalyst tablet. The sizes of NiO crystals of a commercial Pricat catalyst and the Ni-SA catalyst prepared in this study were $35{\AA}$ and $38{\AA}$, respectively. The pore volume and pore size of the Ni-SA catalyst was much larger than the pore volume and pore size of the Pricat catalyst. In addition, the average particle size of the Ni-SA catalyst was much smaller than that of the Pricat catalyst. The triglyceride hydrogenation reaction was carried out in a semi-batch reactor using catalysts impregnated with oil and molded into tablets. It was found that the Ni-SA catalyst was superior to the commercial Pricat catalyst in triglyceride hydrogenation, which could be ascribed to the raw material and the products being less influenced by the diffusion resistance in the pores of the Ni-SA catalyst. The Ni-SA catalyst prepared in this study has the potential to replace the Pricat catalyst as a catalyst for use in the commercial process for hydrogenation of triglyceride.

A Study on Thermal Stability Improvement in Ni Germanide/p-Ge using Co interlayer for Ge MOSFETs

  • Shin, Geon-Ho;Kim, Jeyoung;Li, Meng;Lee, Jeongchan;Lee, Ga-Won;Oh, Jungwoo;Lee, Hi-Deok
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.2
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    • pp.277-282
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    • 2017
  • Nickel germanide (NiGe) is one of the most promising alloy materials for source/drain (S/D) of Ge MOSFETs. However, NiGe has limited thermal stability up to $450^{\circ}C$ which is a challenge for fabrication of Ge MOSFETs. In this paper, a novel method is proposed to improve the thermal stability of NiGe using Co interlayer. As a result, we found that the thermal stability of NiGe was improved from $450^{\circ}C$ to $570^{\circ}C$ by using the proposed Co interlayer. Furthermore, we found that current-voltage (I-V) characteristic was improved a little by using Co/Ni/TiN structure after post-annealing. Therefore, NiGe formed by the proposed Co interlayer that is, Co/Ni/TiN structure, is a promising technology for S/D contact of Ge MOSFETs.

Fabrication of Ni-AC/TiO2Composites and their Photocatalytic Activity for Degradation of Methylene Blue

  • Oh, Won-Chun;Son, Joo-Hee;Zhang, Kan;Meng, Ze-Da;Zhang, Feng-Jun;Chen, Ming-Liang
    • Journal of the Korean Ceramic Society
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    • v.46 no.1
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    • pp.1-9
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    • 2009
  • Activated carbon modified with nickel (Ni-AC) was employed the for preparation of Ni-activated carbon/$TiO_2$ (Ni-AC/$TiO_2$) composites. The $N_2$ adsorption data showed that the composites had a decreased surface area compared with pristine AC. This indicated blocking of the micropores on the surface of the AC, which was further supported by observation via SEM. XRD results showed that the Ni-AC/$TiO_2$ composite contained a mixed anatase and rutile phase while the untreated AC/$TiO_2$ contained only a typical single and clear anatase phase. EDX results showed the presence of C, O, and Ti with Ni peaks on the composites of Ni-AC/$TiO_2$. Subsequently, the photocatalytic effects on methylene blue (MB) were investigated. The improved decomposition of MB showed the combined effects of adsorptions and photo degradation. In particular, composites treated with Ni enhanced the photo degradation behaviors of MB.

Palladium-Nickel Alloy Electrodeposition Using Ethylenediamine as Complexing Agent (에틸렌디아민을 착화제로 사용하는 팔라듐-니켈 합금도금)

  • Choi, Byungha;Sohn, Ho-Sang;Kim, Kyung Tae;Son, Injoon
    • Journal of Surface Science and Engineering
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    • v.47 no.5
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    • pp.215-220
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    • 2014
  • Electrodeposition behaviors of Pd-Ni alloys were investigated from the polarization curves in a solution containing ethylenediamine as complexing agent. The microstructure and hardness of electrodeposited Pd-Ni alloys were also characterized. Codeposition of Pd-Ni alloys was successfully performed in the wide current density ranging from 2 to $5000A{\cdot}m^{-2}$ because the deposition potential of Pd became close to that of Ni in the ethylenediamine-contained solution. It was also found from X-ray diffraction patterns that the solid solution between Pd and Ni was formed with variation of the composition of alloys. The measured hardness of Pd-Ni alloys increased with increasing the contents of Ni due to solid solution strengthening and grain refinement. The electrodeposited Pd-Ni alloys also exhibited a crack free smooth surface morphology from the SEM observation.

Nickel Complexes Having (N-C-N) Tridentate Ligands ((N-C-N) 세자리 리간드를 가지는 니켈 착물)

  • Lee, Dong-Hwan;Park, Soon-Heum
    • Journal of the Korean Chemical Society
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    • v.51 no.6
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    • pp.499-505
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    • 2007
  • Monomeric complexes of nickel(II) having terdentate bis(imino)aryl ligands (N,C,N-pincer) are reported. New complexes (2,6-(ArN=CH)2C6H3)NiBr (Ar=2,6-dimethylphenyl (1), 2,6-diisopropylphenyl (2)) have been synthesized through oxidative addition of 1,3-(ArN=CH)2C6H3Br (bis(N-Ar)-2-bromoisophthalaldimine: Ar=Ph-2,6-Me2, Ph-2,6-iPr2) to Ni(COD)2 (COD=1,5-cyclooctadiene), in high yields. The development of a synthetic route to ligands and nickel complexes is outlined. The complexes were characterized by IR, 1H-NMR and elemental analysis. Full characterization of complexes 1 and 2 is discussed. An investigation into the catalytic activity of the complexes in ethylene polymerization was performed, resulting in no formation of polyethylenes but producing a small amount of oily oligomers. Preliminary results indicate that the pincer complexes were found to be inactive as catalysts in ethylene polymerization.

Studies on the Active Materials of Alkaline Storage Battery(II) Electrochemical Behavior of. Nickel Anode (알칼리 축전지의 활물질에 관한 연구(II)-니켈양극의 전기화학적 거동-)

  • 주충렬;이주성
    • Journal of Surface Science and Engineering
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    • v.15 no.3
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    • pp.146-151
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    • 1982
  • The electrochemical reaction behavior of nickel electrode of the nickel-cadium battery system in potassium hydroxide solution has been studied by cyclic voltammetry, controlled potential electrolysis and X-ray diffraction method. It has been found that the reaction mechanism of positive nickel electrode for charging was assumed to be proten transfer step with a rate controlling diffusion process and char-ging state of positive electrode was amorphous $\beta$-NiOOH.

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