• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.683-693
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• 2014

This study was carried out to investigate the characteristics of the organic liquid fertilizer and find out optimum fermentation conditions of Effective Microorganisms (EM) including ascidian tunic. During the EM fermentation by adding ascidian tunic, electrical conductivity (EC) was increased, contrast to decrease the pH value, on related to the initial dosage molasses rate. Additionally, the total nitrogen quantity was shown to be increased on EM fermentation and the most effective increasing was recorded up to 220% on more than 15% molasses dosage condition. The phosphorus quantity was to be maximum rate on 21th of EM fermentation, and other contents, such to potassium, calcium, magnesium, sodium, had be shown an increasing patten during the fermentation period. After the EM fermentation, the concentration of hazardous material (Zn, As, Cd, Cu, Cr, Hg, Ni, pb) was measured below than the official criteria for commercial fertilizer. As a effective material in fermentated fertilizer, the 29 kinds free amino acids were detected and their total concentration was measured to 7080.94 mg/L.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3589-3595
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• 2013

Changes of phenolics, antioxidant activities and fatty acid contents were determined in the mangrove plant exposed to Cu, Ni and Cd. Propagules of Rhizophora mangle were cultured for 12 weeks under the Cu (0.01 and 1 ppm), Ni (0.1 and 10 oom) and Cd (0.1 and 10 ppm) stresses. In comparison with control, morphological changes of mangrove root were not observed in 12 weeks. Significant changes of phenolics were not detected and antioxidant activities were dramatically increased in the metal-treated mangroves. Fatty acid, C14:1, C15:1 and C18:3n-6, contents were changed in the all of tested propagules. These results shows that DPPH radical scavenging assay and determination of fatty acid contents could be useful biomarkers for diagnosing responses of mangrove plant under heavy metal stress.

• The Journal of the Petrological Society of Korea
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• v.12 no.4
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• pp.170-183
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• 2003

The Sokli complex in the northeastern Baltic Shield (Finland) forms a part of the extensive Devonian Kola Alkaline Province. The complex contains ultramafic lamprophyres occurring as dikes of millimetric to metric thickness. The Sokli ultramafic lamprophyres have petrographical and geochemical affinities with aillikite. High concentrations of Cr and Ni with low Al$_2$O$_3$ content of the Sokli aillikites indicate a strongly depleted harzburgitic source. However, compared to the kimberlites, the lower Cr and Ni contents and mg-number with weaker HREE depletion of the Sokli aillilkites imply a smaller proportion of garnet in the source and thus suggest a shallower melting depth of the source. In order to account for high concentrations of all incompatible elements and LREEs, with high volatile content (especially CO$_2$), an additional enriched material is thought to have been incorporated into the Sokli aillikite source. An anomalous enrichment of K in the Sokli aillikites, compared to nearby ultrapotassic rocks and world-wide ultramafic lamprophyres, indicate a presence of K-rich phase (probably phlogopite) in the source mantle.

• Journal of the Korean Society of Tobacco Science
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• v.1 no.2
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• pp.103-110
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• 1979

The contents of Sodium, Magnesium, Iron, nickel , Copper, Maganese and Zinc in Korean tobacco leaves Produced in 1978, were investigated. The contents of each mineral element in tobacco leaves of various varieties were as follows ; Mg was 5370$\mu{g}/g-7640\mu{g}/g$, Burley> Flue -cured >Native. Mn was 210$\mu{g}/g-1290\mu{g}/g$, Burley>Flue -cured>Native. Fe was 330$\mu{g}/g-590\mu{g}/g$, Burley>Flue -cured>Native. Zn was 500$\mu{g}/g$ -100, Native > Burley>Flue-cured. Na, Ni and Cu showed no difference between the types. The contents of Ha, Mg, Mn, Ni and Cu were reduced in the order of Heavy 5, 3, 1 and increased in the order of Light 1, 3, 5 grades. The correlation coefficient (r) between Mg and grade in Hicks, SC 72 and HC 2326 were 0.770-0.981, and significance level was 0.1 % .

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.220-225
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• 1994

This study was conducted to investigate the influence of treatment of fly ash on heavy metal contents in the grain. Rice was cultivated on the two types of paddy field, clay loam and sandy loam soil, with 0, 4, 8, 12t/10a of anthracite fly ash and bituminous coal fly ash, respectively. And soybean was cultivated on the same types of upland field with those of 0, 3, 6, 9t/10a, respectively. Also. rice and soybean were cultivated the same types of paddy and upland field with those ashes of 0, 12ton/10a and 0, 9ton/10a, yearly for three years. At the harvest time, the heavy metal contents in rice and soybean were Investigated. The results were summarized as follows : 1. Amount of application. 1) The contents of Cd in brown rice increased in the clay loam soil. Cr and Ni increased sandy loam soil with the application of anthracite fly ash. 2) The contents of Zn in rice increased in the sandy loam soil with the application of bituminous coal fly ash. 3) The contents of Cu in soybean increased with the application of anthracite and bituminous coal fly ash, but Zn, Pb, Cr and Ni increased only with the bituminous. 2. Successive application. 1) The contents of Cd in brown rice increased in the clay and sandy loam soil, however Cu, Zn, Ni, Cr and Fe increased only in sandy loam soil with the anthracite fly ash. 2) The contents of Cr in soybean were increased in the clay and sandy loam soil, but Cu, Fe increased only sandy loam soil with anthracite fly ash. 3) The contents of Cd, Zn, and Cr in brown rice increased in the clay and sandy loam soil, but those of Cu, Mn increased only in the sandy loam soil with application of bituminous. 4) The contents of Cd, Pb, and Cr in soybean increased in the sandy loam soil with the application of bituminous coal fly ash.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.2
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• pp.71-79
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• 2021

In this study, we have successfully fabricated the Sn-Ni paste and evaluated the bonding properties for high-temperature endurable EV (Electric Vehicle) power module applications. From evaluating of the micro-structural changes in the TLPS (Transient Liquid Phase Sintering) joints with Sn and Ni contents in the Sn-Ni pastes, a lack of Ni powders and Ni particle agglomerations by Ni surplus were observed in the Sn-20Ni and Sn-50Ni joints (in wt.%), respectively. In contrast, relatively dense microstructures are observed in the Sn-30Ni and Sn-40Ni TLPS joints. From differential scanning calorimetry (DSC) thermal analysis results of the fabricated Sn-Ni paste and TLPS bonded joints, we confirmed that the complete reactions of Sn with Ni to form Ni-Sn intermetallic compounds (IMCs) at bonding temperatures occurred, and there is no remaining Sn in the joints after TLPS bonding. In addition, the interfacial reactions and IMC phase changes of the Sn-30Ni joints under various bonding temperatures were reported, and their mechanical shear strength were investigated. The TLPS bonded joints were mainly composed of residual Ni particles and Ni₃Sn₄ intermetallic phase. The average shear strength tended to increase with increasing bonding temperature. Our results indicated a high shear strength value of approximately 30 MPa at a bonding temperature of 270 ℃ and a bonding time of 30 min.

• Journal of the Korean Ceramic Society
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• v.40 no.1
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• pp.11-17
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• 2003

The effect of$ZrO_2$addition on the microstructure and electrical properties of Ni-Mn oxide NTC thermistors was studied. Major phases present in the sintered bodies of $Ni_{1.0}Mn_{2-x}Zr_xO_4$ were the solid solutions of Ni-Mn-Zr oxides with a cubic spinel structure and the $ZrO_2$ with a tetragonal structure. The $ZrO_2$ was formed by the partial decomposition or incomplete formation of the Ni-Mn-Zr oxides during sintering. With increasing the amount of added $ZrO_2$, the $ZrO_2$ phase increased. The relationship between log resistivity (log p) and the reciprocal of absolute temperature (1/T) of the NTC thermistors prepared was linear, indicative of NTC characteristics. The resistivity, B constant and activation energy of the thermistors increased with increasing $ZrO_2$ content.

• Korean Journal of Materials Research
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• v.8 no.8
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• pp.685-692
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• 1998

Since a wet-seal area of Molten Carbonate Fuel Cell (MCFC) operated at $650^{\circ}C$ is exposed to severe environment, a life-time of MCFC is influenced by the corrosion resistance of separator. In order to improve corrosion resistance of 316L stainless steel used as separator material, AI- base alloy such as NiAI has been widely used as coat¬ing material on the wet-seal area. The purpose of this work is to develope a more protective coating material by adding yttrium on NiAI alloy. An immersion test and a polarization test were performed in molten carbonate salt at $650^{\circ}C$ to estimate corrosion resistance of the NiAI alloy and the NiAl/Y alloys with up to L5at% yttrium. NiAl/Y alloys showed better corrosion resistance than NiAI alloy. We found that more than 0.7 at% yttrium was required to improve the corrosion resistance of NiAI alloy in molten carbonate salt at $650^{\circ}C$.

• Korean Journal of Metals and Materials
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• v.47 no.9
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• pp.533-541
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• 2009

Materials used for a reactor pressure vessel(RPV) are required high strength and toughness, which determine the safety margin and life of a reactor. Ni-Mo-Cr low alloy steel shows better mechanical properties than existing RPV steels due to higher Ni and Cr contents compared to the existing RPV steels. The present study focuses on effects of Ni, Cr contents on the cleavage fracture toughness of Ni-Mo-Cr low alloy steels in the transition temperature region. The fracture toughness was characterized by a 3-point bend test of precracked Charpy V-notch(PCVN) specimens based on ASTM E1921-08. The test results indicated that the fracture toughness was considerably improved with an increase of Ni and Cr contents. Especially, control of Cr content was more effective in improving fracture toughness than manipulating Ni content, though Charpy impact toughness was changed more extensively by adjusting Ni content. These differences between changes in the fracture toughness and that in the impact toughness were derived from microstructural features, such as martensite lath size and carbide precipitation behavior.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.35.1-35.1
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• 2009

오스테나이트계 Fe-10Cr-10Ni-xC(x=0.2, 0.5, 0.6and 0.7wt.%)합금에서 변형유기마르텐사이트상변태가 Sliding 마모저항성에 미치는영향을 탄소 및 온도에 따라 조사하였다. 변형유기마르텐사이트상변태가 미치는 영향을 살펴보기 위해 석출물적고 grain의 크기가 비슷한 합금내에서 조사하였다. 변형유기마르텐사이트상변태가 일어나는데 필요한 에너지를 변형률-응력 곡선을 통해 구할 수 있으며, 이를 임계변형에너지라 규명했다. 그 결과, 상온에서 Carbon 함량에 따라 변형유기마르텐사이트상변태가 일어나는데 필요한 임계변형에너지는 증가하였으며, Sliding 마모저항성은 저하되었다. 이는 carbon이 오스테나이트 안정화원소(austenite stabilityelement)이므로 carbon 함량이 증가할수록 변형유기마르텐사이트상변태가 유발하기위해서는 많은 에너지가 필요하기 때문에 low C에 비해 high C의 마모저항성이 저하된 것으로 사료된다. 또한 변형유기마르텐사이트상변태가 고온 Sliding 마모저항성에 미치는 영향을 살펴보기 위해 Fe-Cr-Ni-xC(x=0.2, 0.5, 0.6 and 0.7wt.%)합금을 온도별(25, 100, $300^{\circ}C$)로 조사하였다.