• Corrosion Science and Technology
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• 제13권4호
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• pp.145-151
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• 2014

The objectives of this study are to investigate the effect of the concentration ratios of Ni and Fe ions on crud deposition onto the fuel cladding surface in the simulated primary environments of a pressurized water reactor. Crud deposition tests were conducted in the Ni and Fe concentration ratios of 20:20 ppm, 39:1 ppm and 1:39 ppm at $325^{\circ}C$ for 14 days. In the case of the same Ni and Fe ion ratio (20:20), nickel ferrite with a polyhedral shape was formed. Nickel oxide deposits with a needle shape were formed in the condition of high Ni to Fe ion ratio (39:1), While polyhedral iron oxide and needle-like nickel oxide formed in the condition of low Ni to Fe ion ratio (1:39). The amount of deposits increased, when Fe oxides were formed. This indicates that Fe rich oxides stimulated Ni oxide deposition.

• 한국표면공학회지
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• 제43권5호
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• pp.243-247
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• 2010

The micro Vickers hardness and internal stress of Ni-Fe metal thin film synthesized by electrodeposition method at $25^{\circ}C$ were studied as a function of bath composition, and surface microstructure and atomic compositions of thin films were investigated by SEM and EDS. And the shape change of $200\;{\AA}$ Ni-Fe nanowires made using anodic aluminum oxide(AAO) templates by electrodeposition method were observed by SEM as a function of ultrasonic treatment time and bath composition. The Fe deposition contents on the substrate non-linearly increased with Fe ion concentration over total metal ion concentration. In case of low Fe contents film, the grain size is smaller and denser than high Fe contents deposited films, and the micro Vickers hardness increased with Fe contents of electrodeposited films. These results affected the shape change of nanowire after ultrasonic treatments.

• 대한화학회지
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• 제56권4호
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• pp.448-458
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• 2012

In order to develop alloy resistance in aggressive sulphat ion, the corrosion behavior of metallic glasses $Ni_{92{\cdot}3}Si_{4.5}B_{32}$, $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ (at %) at different concentrations of $H_2SO_4$ solutions was examined by electrochemical methods and Scanning Electron Microscope (SEM) and X-ray Photoelectron Microscopy (XPS) analyses. The corrosion kinetics and passivation behavior was studied. A direct proportion was observed between the corrosion rate and acid concentration in the case of $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ alloys. Critical concentration was observed in the case of $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ alloy. The influence of the alloying element is reflected in the increasing resistance of the protective film. XPS analysis confirms that the protection film on the $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ alloy was NiS which is less protective than that formed on Cr containing alloys. The corrosion rate of $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$. alloys containing 7% and 13% Cr are $7.90-26.1{\times}10^{-3}$ mm/y which is lower about 43-54 times of the alloy $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ (free of Cr). The high resistance of $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ alloy at the very aggressive media may due to thicker passive film of $Cr_2O_3$ which hydrated to hydrated chromium oxyhydroxide.

• 한국자기학회지
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• 제11권4호
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• pp.151-156
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• 2001

최근 망간산화물 Ln$_{1-x}$A$_{x}$MnO$_3$(Ln=La, Pr, Nd등의 lanthannide; A=Ca, Sr, Ba, Pb 등의 +2가 이온)는 초거대자기저항(CMR) 특성으로 많은 연구그룹의 주목을 받고 있다. 그런데 chalcogenide spinels에서도 CMR특성이 관측되는 것으로 보고되고 있다. 본 논문에서는 chalcogenide Ni$_{x}$Fe$_{1-x}$Cr$_2$S$_4$에서 Ni이온이 CMR 특성에 미치는 효과를 X선 회절 실험, 자기저항측정, 그리고 Mossbauer 분광실험으로 조사하였다. 그 결과 Ni이온의 치환은 Jahn-Teller distortion을 심화시키고, 또한 T$_{c}$ 값에 증가를 초래하여 CMR현상에 영향을 준다. T$_{c}$ 부근에서 일어나는 CMR현상은 망간산화물에서의 $Mn^{3+}$ 와 $Mn^{4+}$ 사이의 이중교환상호작용과는 다르게 동적 Jahn-Teller효과에 기인한 도체-반도체전이와 자기장하에서 절반 금속성의 에너지밴드구조를 갖는 시료의 스핀편향에 의한 전도현상 그리고 자기구역의 정렬에 의하여 발생되는 것으로 나타났다.

• 한국균학회지
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• 제19권3호
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• pp.220-225
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• 1991

1. 표고버섯 중 정제된 ATPase는 $Fe^{3+},\;Fe^{2+},\;Cd^{2+},\;Mg^{2+},\;K^{+}$ 및 $Co^{2+}$ 이온에 의하여 활성화 되었으나 $Zn^{2+},\;Ca^{2+},\;Cu^{2+}$ 및 $Ni^{2+}$ 이온에 의하여는 그 활성도가 억제되었다. 2. 5 mM $Fe^{3+}$, 10 mM $Fe^{2+}$, 1 mM $Cd^{2+}$, 5 mM $Mg^{2+}$, 5 mM $K^{+}$ 및 5 mM $Co^{2+}$이온은 이효소의 활성을 각각 130, 65, 65, 68, 105 및 23% 증가시켰다. 3.10 mM $Zn^{2+}$, 10 mM $Ca^{2+}$, 0.5 mM $Cu^{2+}$ 그리고 10 mM $Ni^{2+}$ 이온은 이효소의 활성을 각각 18, 19, 27% 그리고 30%의 억제효과를 보였다. 4. 10 mM ${Co_3}^{2-}$, 20 mM $CN^{-}$, 20 mM ${CH_3COO}^{-}$ 그리고 20 mM ${NO_3}^{-}$의 음이온은 이효소의 활성을각각 98, 95, 70% 그리고 50%를 억제시켰으나,${SO_4}^{2-}$ 이온은 농도증가에 따라 활성화 되었고, 20 mM 용액에서 21%로 활성도 증가의 최대치를 보였다.

• 한국재료학회지
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• 제11권10호
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• pp.859-862
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• 2001

The crystal structure and magnetic properties of the $Ni_{1-x} Cd_xFeAlO_4$(0$\leq$x$\leq$0.5) have been investigated by means of X-ray diffractometry and Mossbauer spectroscopy. The samples($0\leq$x$\leq$0.5) have been prepared by the ceramic sintering method. The X-ray diffraction pattern shows that the crystal structure of the samples is a cubic spinel type. The lattice constant has been found by extrapolation using the Nelson- Riley function and it increases slightly from $8.321{\AA}$ to $8.410{\AA}$ with Cd concentration. The Mossbauer spectra for x<0.4 show a superposition of two sextets and a paramagnetic doublet at room temperature. The cation distribution for x=0 was determined to be $[Fe_{0.75}Al_{0.25}]^A[NiFe_{0.25}Al_{0.75}^BO_4$. The superparamagnetic doublet for x< 0.4 seems to be due to A1 ion in tetrahedral site by the superparamagnetic clustering effect.

• 자원리싸이클링
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• 제16권6호
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• pp.3-9
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• 2007

생활 폐기물은 대부분 유리류와 자기류뿐만 아니라 많은 양의 iron을 함유하고 있으며 약 $3{\sim}11%$에 달한다. 대부분의 iron은 Ni-Fe와 Ni-Cr-Fe 같은 합금으로 존재하거나, 부식방지와 광택을 위해 Ni와 Cr로 도금된 iron으로 존재하고 있기 때문에 소각로에서 소각될 경우 철 재품 표면에 심하게 파손된 $Fe_3O_4$층과 함께 $NiFe_2O_4$와 FeCr_2O_4$을 형성하게 되어 바닥재에 존재하게 되어 중금속산화물 층을 형성시킬 수 있다. iron은 자력이 매우 강해 자력선별에 의해 쉽게 선별되며 이러한 효과로 인해 중금속 산화물의 선별까지 얻을 수 있다. 또한 바닥재는 다양한 Ni와 Cr 산화물들을 함유하고 있으며, Ni와 Cr은 강자성을 띈 물질이기 때문에 자력선별에 의해 큰 영향을 받을 수 있다. 따라서 자력선별에 따른 Ni와 Cr의 거동에 대해 조사하였으며 그 밖의 다른 중금속(Cu, Pb, Cd, As)들의 거동 또한 확인해 보았다. 그 결과 Ni와 Cr은 약 $45{\sim}50%$의 선별율을 보였으며, Cu와 Pb는 $15{\sim}20%$을 나타냈다. 또한 자력선별 전과 후의 바닥재에 대해 Ni와 Cr의 용출량을 확인해본 결과 자력선별 후 바닥재의 용출량이 더 낮음을 확인할 수 있었다.

• 환경위생공학
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• 제24권1호
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• pp.33-39
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• 2009

In order to investigate effect of metal ion and antioxidant on rancidity of crude rapeseed oil (CRO), $Fe^{2+}$, $Cu^{2+}$, $Co^{2+}$, $Ni^{2+}$, $Cr^{2+}$, $Sn^{2+}$, $Mn^{2+}$, $Zn^{2+}$, and antioxidants including BHA, Vitamin C, and Tocopherol were used. The specific gravity and refractive index of CRO were $0.92g/cm^3$ and 1.45, respectively. The chromaticities of light, red, and yellow in CRO were 88.6 and 98.7, respectively. Among various fatty acids, Oleic acid (C18:1) concentration was highest, 62.3% and Linoleic acid (C18:2) concentration was 19.16%. In the case of Linolenic acid (C18:3) and Palmitic acid (C16:0), they were 9.88 and 5.2%, respectively. The concentrations of unsaturated fatty acids and saturated fatty acid were 92.2 and 7.8%, respectively. The degree of expediting rancidity of CRO was an order of $Fe^{2+}$> $Cu^{2+}$> $Cr^{2+}$> $Zn^{2+}$> $Ni^{2+}$> $Al^{2+}$> $Mn^{2+}$> $Mn^{2+}$> $Sn^{2+}$> $Co^{2+}$> $Li^{2+}$. Especially, when $Cu^{2+}$ and $Fe^{2+}$ was used, the peroxide value concentration was about 4.0 fold higher than non addition of them. The inhibition effect of rancidity of CRO using antioxidant with $Cu^{2+}$ and $Fe^{2+}$ was an order of BHA> Vitamin C> Tocopherol.

• 환경위생공학
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• 제9권2호
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• pp.8-23
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• 1994

During the period from Mar., 1991 to Feb., 1992 66 tSP samples were collected by Hi volume air sampler at 1 sampling site in Seoul and the amount of concentration of 21 components(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Al, Ba, Ca, Cd, Cr, Cu, Fe, It Mg, Mn, Na, Ni, Pt Si, Ti, Zn, Zr ) were measured. And monthly and seasonal variation were surveyed and the principal component analysis( PCA ) were carried out with respect to these amount of pollutants, minimum of visibility and radiation on a horizontal surface. The total amount of soluble ion in water was high in order o(SO$_{4}$$^{2-}$> NO$_{3}$$^{-}$> N%'>Cl$^{-}$ and metal ion was high in order of Na> Ca>Si> Fe> Al> K> Mg> Zn> Pb> Cu>Ti> Mn > Ba> Cr> Zr> Ni> Cd. There was Seasonal variation in concentration for SO$_{4}$$^{2-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Na, Al, Ca, Bt Mg, Fe and Si. It was assumed that the components of the highest concentration on April were depend on yellow sand and the frequency of wind velocity and direction. As the results of PCA, the amount of pollution components was able to characterized with two principal components(Z$_{1}$, Z$_{2}$ ). The first principal components Z$_{1}$ was considered to be a factor indicating the pollutants originated from natural generation and The second principal components Z$_{2}$ was considered to be a factor indicating the pollutants originated from human work. The monthly concentration of pollutants in ISP, minimum of visibility and radiation on a horizontal surface was possible to evaluate by the use of these two principal components Z$_{1}$ and Z$_{2}$ .

• Korean Chemical Engineering Research
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• 제48권2호
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• pp.157-163
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• 2010

CRT 용 shadow mask의 생산속도 향상을 위해 첨가제를 투입한 염화제이철 수용액을 개발하였고 이를 shadow mask의 식각속도 향상에 적용하였다. $Fe(ClO_4)_3$ 첨가제를 종래의 식각용액인 염화제이철 수용액에 투입한 결과, shadow mask의 식각속도가 크게 향상되었으며, 이때 첨가제의 농도가 증가할수록 식각속도가 증가함을 알 수 있었다. 또한 첨가제가 투입된 식각용액으로 순수 니켈과 철-니켈 합금(Invar 강)의 식각속도를 비교한 결과, 대부분의 공정조건에서 둘 사이의 식각속도 차이가 작음을 알 수 있었고, 이는 첨가제의 투입에 따라 니켈과 철의 식각속도가 모두 향상된 결과로 해석되었다. 첨가제의 주입에 따라 식각속도가 증가하는 이유는, 첨가제 내의 음이온인 $ClO^{4-}$가 염화제이철 수용액 내의 $Cl^-$에 비해 전자를 이동하는 가교로서의 역할이 우수하여 전자를 더 빠르게 이동시킬 수 있기 때문인 것으로 추정된다.