• Journal of Plant Biology
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• v.16 no.3_4
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• pp.40-44
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• 1973

Hawkeye(Fe-chlorosis resistant) and PI 54619-5-1(Fe-chlorosis sensitive) soybeans were grown with and without DPTA(diethylene triamine pentaacetic acid) in Yolo loam soil. The major purpose of the study was to compare leaf-stem distribution of microelements for different treatments which increase concentrations of microelements in plants to evaluate the role of the chelating agent in increasing translocation of the microelements. Plant responses and yields were recorded and Fe, Mn, Zn, Cu, Al, Co, N, Sn, Pb and Mo contents of leaves and stems were determined by emission spectrography. Sulfur(soil pH4) increased leaf concentrations of Mn, Zn, Cu, CO, Ni, Sn and Pb. DTPA, particularly at 50ppm in soil, increased leaf concentrations of Fe, Mn, Zn, Cu, Co, Ni and Mo. It increased Ti in leaves for the PI 54619-5-1 soybeans only. DTPA increased the ratios of the concentration in leaves to that in stems for Fe, Zn, Cu, Al, Ti, CO, Ni and Mo. Sulfur which increased the microelement concentration in both leaves and stems did not have this effect. DTPA increased the ratio at soil pH 6 and 8.5 in leaves to that in stems of the bush bean plants for Fe, Zn, Cu, Ni, but to a lesser extent in bush beans than in soybeans. PI 54619-5-1 soybeans tended to contain less of most of the metals than did Hawkeye soybeans.

• Carbon letters
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• v.24
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• pp.103-110
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• 2017

Carbon-based magnetic nanostructures in several instances have resulted in improved physicochemical and catalytic properties when compared to multi-wall carbon nanotubes (MWCNTs) and magnetic nanoparticles. In this study, magnetic MWCNTs with a structure of $Ni_xZn_xFe_2O_4/MWCNT$ as peroxidase mimics were fabricated by the one-pot hydrothermal method. The structure, composition and morphology of the nanocomposites were characterized with X-ray diffraction (XRD), Fourier transform infrared spectroscopy and transmission electron microscopy. The magnetic properties were investigated with a vibrating sample magnetometer. The peroxidase-like catalytic activity of the nanocomposites was investigated by colorimetric and electrochemical tests with 3,3',5,5'-tetramethylbenzidine (TMB) and $H_2O_2$ as the substrates. The results show that the synthesis of the nanocomposites was successfully performed. XRD analysis confirmed the crystalline structures of the $Ni_xZn_xFe_2O_4/MWCNT$ nanohybrids and MWCNTs. The main peaks of the $Ni_xZn_xFe_2O_4/MWCNT$s crystals were presented. The $Ni_{0.25}Zn_{0.25}Fe_2O_4/MWCNT$ and $Ni_{0.5}Zn_{0.5}Fe_2O_4/MWCNT$ nanocatalysts showed nearly similar physicochemical properties, but the $Ni_{0.5}Zn_{0.5}Fe_2O_4/MWCNT$ nanocatalyst was more appropriate than the $Ni_{0.25}Zn_{0.25}Fe_2O_4/MWCNT$ nanocatalyst in terms of the magnetic properties and catalytic activity. The optimum peroxidase-like activity of the nanocatalysts was obtained at pH 3.0. The $Ni_{0.5}Zn_{0.5}Fe_2O_4/MWCNT$ nanocatalyst exhibited a good peroxidase-like activity. These magnetic nanocatalysts can be suitable candidates for future enzyme-based applications such as the detection of glucose and $H_2O_2$.

• Journal of the Korean Magnetics Society
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• v.8 no.5
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• pp.295-299
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• 1998

The magnetic thin films can be prepared without vacuum process and under the low temperature(<100 $^{\circ}C$) by ferrite plating. We have performed ferrite plating of $Ni_xFe_{3-x}O_4$ (x=0.162~0.138) films on cover glass at the substrate temperature 80 $^{\circ}C$ and pH range of the oxidizing solution, 7.1~8.8. the crystal structure of the samples has been identified as a single phase of polycrystal spinel structure by x-ray diffraction technique. The deposition rate and the grain size of the film increased with the pH of oxidizing solution. The coercive force (H_C)$ decreased with the pH of oxidizing solution.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1018-1025
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• 2011

The improved properties of corrosion for 90Cu10NiFe alloy in natural seawater were explained by sodium diethyl dithio carbamate(NaDDC), namely organic compound, which is reagent for heavy metal extractions of waste water. The efficiency of NaDDC as corrosion inhibitor for 90Cu10NiFe alloy has been investigated in seawater after immersion in various concentrations of NaDDC solutions for 12~36hrs at pH 8.2 by weight loss test and electrochemical techniques including potentiodynamic polarization and SEM-EDS measurements. The results showed that the corrosion resistance of 90Cu10NiFe alloy improves with the increasing concentration of NaDDC but it did not improves with increasing time any more, so the highest inhibition efficiency was 93% at 100mg/L, 36hrs. The results obtained from weight losses and corrosion rates in polarization curve measurements were in good agreement. Therefore, it showed that NaDDC is a good inhibitor for copper corrosion of 90Cu10NiFe alloy.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.153-154
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• 2009

원자력발전소 증기발생기 전열관 보수 기술의 하나로 니켈 합금 전기 도금이 연구되고 있다. 여러 도금 공정변수 중 peak current density를 달리하여 Ni-P-Fe 전기도금층을 제조한 뒤, 열처리 온도 $325^{\circ}C$에서 10, 30일간 열처리를 한 후, 인장강도와 연신율을 측정하고, 그 파단면을 관찰하였다. 50mA/$cm^2$로 제조된 도금층은 100mA/$cm^2$로 제조된 도금층에 비해 우수한 열적안정성을 가짐을 알 수 있었다.

• Journal of the Korean Magnetics Society
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• v.23 no.3
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• pp.98-103
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• 2013

The magnetic easy axis of the ferromagnetic layer for the dual-type GMR-SV (giant magnetoresistance-spin valve) having NiFe/Cu/NiFe/IrMn/NiFe/Cu/NiFe multuilayer structure controlled by the post annealing treatment. The magnetoresistive curves of a dual-type IrMn based GMR-SV depending on the direction of the magnetic easy axis of the free and the pinned layers are measured by the different angles for the applied fields. By investigating the switching process of magnetization for an arbitrary measuring direction, the optimum annealing temperature having a steady and isotropy magnetic sensitivity of 2.0 %/Oe was $105^{\circ}C$. This result suggests that the in-plane orthogonal magnetization for the dual-type GMR-SV film can be used by a high sensitive biosensor.

• Journal of Powder Materials
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• v.5 no.1
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• pp.42-49
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• 1998

A study on the improvement of the impact energy in 93W heavy alloy with a Ni/Fe ratio of 9/1 has been carried out as a function of heat treatment temperature. The obtained results were compared to that of the traditional alloy system in which the Ni/Fe ratio is 7/3 or 8/2. With increasing heat treatment temperature from 1150 to 125$0^{\circ}C$, the impact energy of the alloy with the Ni/Fe ratio of 9/1 is remarkably increased from 42 to 72 J, which is higher than that of traditional alloy, up to 118$0^{\circ}C$ and then saturated. Fracture mode was also changed from brittle W/W boundary failure to W cleavage. The temperature showing the dramatic shrinkage by dilatometric anaysis of the heavy alloy with Ni/Fe ratio of 9/1 was found to be 1483 $^{\circ}C$, which is higher than that (146$0^{\circ}C$) of the heavy alloy with Ni/Fe ratio of 7/3. Auger Electron Spectroscopy showed that the segregation of impurities, such as S, P, and C in W/W grain boundary was considerably decreased with increasing heat treatment temperature from 1150 to l18$0^{\circ}C$. From the above results, it was found that the impurity segregation in W/W grain boundary played an important role on the decrease of impact properties, and the heat treatment temperature should be appropriately chosen, as considering the Ni/Fe ratio of the alloy, in order to get good impact properties.

• Korean Journal of Environmental Biology
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• v.24 no.4
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• pp.408-415
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• 2006

Serpentines soil have high values of magnesium and low values of calcium, and are usually deficient in N and P, but rich in iron, Ni, silicates. We investigated serpentine soil properties and measured the content of nutrient elements and heavy metals in shoots and root of plant species which were in common at serpentine and non-serpentine areas in Andong, Korea. The soils showed higher pH value above 6.9. The contents of Ni, Cr, Fe and Mg of serpentine soils exhibited 77, 27, 5.5 and 12.5 times more than in non-serpentine soils, respectively. The content of Na was almost same but K was two times higher in non-serpentine soil, compared with serpentine soil. The contents of nutrient element such as K, Ca, Na and P in serpentine plants did not show conspicuous differences with non-serpentine plants. On the other hand, the concentrations of Ni, Cr, Fe, Mg and Mg/Ca were very high in plant on serpentine area. The all plant species collected at the serpentine site were bodenvag plants, which are not restricted to a specific type of substrate. By the plant species and parts of plant tissues, the absorption levels and patterns showed high variation and were species-specific. Carex lanceolata, Lysimachia clethroides and Cynanchum paniculatum contained much chromium and Eupatorium chinense and C. paniculatum exhibited high contents of Ni. In leaf tissue, C. lanceolata, Rubus parvifolius, Festuca ovina, Quercus serrata, and L. clethroides took comparatively large amount of Cr in serpentine area. E. chinense contained large amount of Ni, Cr and Fe in a leaf tissue. The stem of Galium verum, Juniperus rigida included high amount of Cr, Ni and Fe. And C. paniculatum absorbed large amount of Ni and Cr in the stem.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.4
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• pp.322-327
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• 2003

Giant magnetoresistance(GMR) NiO multilayer, which has been used to reading head of highly dense magnetic recording, was fabricated, and oxidized in an air during 80 days to study the dependence of magnetoresistance properties on residual stress in the interfaces. The magnetoresistance ratio and the exchange biasing $field(H_{ex})$ of $NiO(60nm)/Ni_{81}Fe_{19}(5nm)/Co(0.7nm)/Cu(2nm)/Co(0.7nm)/Ni_{81}Fe_{19}(7nm)$ spin valves were increased from 4.9% to 7.3%, and 110 Oe to 170 Oe after natural oxidation in the atmosphere for 80 days, respectively. The sheet resistivity ${\rho}$ decreased from $28{\mu}{\Omega}m$ to $17{\mu}{\Omega}m$, but ${\Delta}p$ did not almost change after the oxidation. Therefore, the increase of MR ratio is due to the decrease in the sheet resistivity. the reduced resistance may result from the increase in the reflection of conduction electrons at the oxidized top surface. Also, the increase in the exchange biasing field is originated from the reduction of residual stress at the interface of $NiO/Ni_{81}Fe_{19}$ according as the aging time increases.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.250-250
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• 2012

Recently, multiferroic materials have attracted much attention due to their fascinating fundamental physical properties and potential technological applications in magnetic/ferroelectric data storage systems, quantum electromagnets, spintronics, and sensor devices. Among single-phase multiferroic materials, $BiFeO_3$, in particular, has received considerable attention because of its very interesting magnetoelectric properties for application to spintronics. Enhanced ferromagnetism was found by Fe-site ion substitution with magnetic ions. In this study, $BiFe_{1-x}Ni_xO_3$ (x=0 and 0.05) bulk ceramic compounds were prepared by solid-state reaction and rapid sintering. High-purity $Bi_2O_3$, $Fe_3O_4$ and NiO powders were mixed with the stoichiometric proportions, and calcined at $450^{\circ}C$ for 24 h to produce $BiFe_{1-x}Ni_xO_3$. Then, the samples were directly put into the oven, which was heated up to $800^{\circ}C$ and sintered in air for 20 min. The crystalline structure of samples was investigated at room temperature by using a Rigaku Miniflex powder diffractometer. The Raman measurements were carried out with a Raman spectrometer with 514.5-nm-excitation Ar+-laser source under air ambient condition on a focused area of $1-{\mu}m$ diameter. The field-dependent magnetization and the temperature-dependent magnetization measurements were performed with a vibrating-sample magnetometer. The x-ray diffraction study demonstrates the compressive stress due to Ni substitution at the Fe site. $BiFe_{0.95}Ni_{0.05}O_3$ exhibits the rhombohedral perovskite structure R3c, similar to $BiFeO_3$. The lattice constant of $BiFe_{0.95}Ni_{0.05}O_3$ is smaller than of $BiFeO_3$ because of the smaller ionic radius of Ni3+ than that of Fe3+. The field-dependent magnetization of $BiFe_{0.95}Ni_{0.05}O_3$ exhibits a clear hysteresis loop at 300 K. The magnetic properties of $BiFe_{0.95}Ni_{0.05}O_3$ were improved at room temperature because of the existence of structurally compressive stress.