• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.485-490
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• 2010

In our previous studies, continuous SiC fiber-reinforced SiC-matrix composites ($SiC_f$/SiC) had been fabricated by two different slurry infiltration methods: vacuum infiltration and electrophoretic deposition (EPD). 12 wt% of $Al_2O_3-Y_2O_3$-MgO with respect to SiC powder was used as additives for liquid-phase assisted sintering. After hot pressing at $1750^{\circ}C$ under 20 MPa for 2 h in Ar atmosphere, a high composite density could be achieved for both cases, whereas the problems such as large grain size and non-uniform distribution of liquid phase were observed, which was resulted in the relatively poor mechanical properties of composites. Therefore, efforts have been made to reduce the grain growth during the sintering, including the optimization for hot pressing condition and utilization of spark plasma sintering using a SiC monolith. Based on the results, spark plasma sintering was found to be effective method in decreasing the amount of sintering additive, time and grain growth, which will be explained in comparison to the results of hot pressing in this paper.

• The Korean Journal of Mycology
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• v.16 no.2
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• pp.95-100
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• 1988

Isozyme band patterns were investigated by isoeletric focusing Esterase and Leucine amino peptidase of Pleurotus spp. in Korea. Esterase patterns of mycelia and fruitbody were distinquished. However, those of primordia, cap and stem were similar. Interspecies differences of Pleurotus ostreatus, P. cornucopiae and P. florida of Esterase zymogram were found. Species identification by electrophoretic zymogram may be a role as an additional taxonomic tool.

• Journal of Sensor Science and Technology
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• v.27 no.1
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• pp.1-5
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• 2018

Two-dimensional (2D) niobate-based nanosheets have attracted attention as high-k dielectric materials. We synthesized strontiumsubstituted calcium niobate ($Ca_{0.8}Sr_{1.2}Nb_3O_{10}$) nanosheets by a two-step cation exchange process from $KCa_{0.8}Sr_{1.2}Nb_3O_{10}$ ceramic. The $K^+$ ions were exchanged with $H^+$ ions, and then H+ ions were exchanged with tetrabutylammonium ($TBA^+$) cations. The $Ca_{0.8}Sr_{1.2}Nb_3O_{10}$ nanosheets were then exfoliated, decreasing the electrostatic interaction between each niobate layer. Furthermore, $Ca_2Nb_3O_{10}$ nanosheets were synthesized in same process for comparison. Each exfoliated nanosheet shows a single-crystal phase and has a lateral size of over 100 nm. The nanosheets were deposited on a $Pt/Ti/SiO_2/Si$ substrate by the electrophoretic deposition (EPD) method at 40 V, followed by ultraviolet irradiation of the films in order to remove the remaining $TBA^+$ ions. The $Ca_{0.8}Sr_{1.2}Nb_3O_{10}$ thin film exhibited twice the dielectric permittivity (~60) and lower dielectric loss than $Ca_2Nb_3O_{10}$ thin films.

• Korean Journal of Food Science and Technology
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• v.18 no.3
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• pp.173-180
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• 1986

To investigate on the biochemical characteristics of muscle fiber, myofibrils and actomyosins were prepared front red muscle and white muscle, and their ATPase activities and SDS-polyacrylamide gel electrophoretic patterns were compared. Also biochemical characteristics of bovine muscle were compared with those of chicken muscle for the detection of species characteristics. SDS-polyacrylamide gel electrophoretic analysis indicated that red muscle contained nlore 30K component of myofibril than white muscle. Differences in KCI concen-tration dependency of actomyosin ATPase activities and ATPase activity-pH cone were observed, when bovine muscle were compared with chicken muscle.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.44-52
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• 2007

Contaminated sediments more than 30 million/$m^3$ is generated from dredging work for harbours and coastal maintenance in Korea. Approximately 300 million/$m^3$ of sediments is dredged to deepen harbours and shipping lanes in US and of which $3{\sim}12million/m^3$ is highly contaminated. Although much is known about technologies for the remediation of heavy metal contaminated soil, much less is known about the treatment of contaminated sediment. In general, negatively charged fine particles will migrate towards positively charged system of electrodes under the influence of electrophoresis. However, the electrically induced migration of colloidal particles contaminated with heavy metals may be hindered by the positively charged heavy metal contaminants adsorbed onto the soil surfaces depending on the contamination level. This paper demonstrates settling behaviour of clayey soil by comparison with electrophoretic particle movement under the effects of heavy metal contamination, applied electric field strength, and its polarity changed by the electrode configuration.

• Korean journal of food and cookery science
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• v.7 no.3
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• pp.13-20
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• 1991

This study was performed to examine the electrophoretic properties of Job's tears (Yulmoo: Coix lachryma-jobi L. var. Ma-yuen Stapf. & Yeomjoo: Coix lachryma-jobi L.) proteins. Albumins, globulins, gliadins and glutelins were extracted from the polished Yulmoo and brown Yeomjoo by the modified Osborne method. For a comparison, rice proteins were extracted and fractionated by the same method. The relative proportions of protein fractions were 17.4 : 19.6 : 55.2 : 7.7% in polished Yulmoo, 12.6 : 62.2 : 4.2 :21.0% in brown Yeomjoo and 14.2 : 57 4 : 0.77 : 27.8% in rice, in the order of albumis, globulins, gliadins and glutelins. Polyacrylamide gel electrophoresis (PAGE) and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) were peformed to identify the subfractions of each protein fraction extracted from polished Yulmoo, brown Yeomjoo and rice. The electro-phoregrams of polyacrylamide gel electrophoresis showed that the same fractions of both polished Yulmoo protein and brown Yeomjoo protein had very similar electrophoretic patterns to each other respectively, but there were significant differences in the patterns between Job's tears proteins and rice proteins.

• Clean Technology
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• v.15 no.3
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• pp.194-201
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• 2009

Reductive reactivity of zero-valent iron nanoparticles was investigated for removal of nitrate-nitrogen which is considered one of the major water pollutants. To elucidate the difference in reactivity between preparation methods, iron nanoparticles were synthesized respectively from microemulsion and aqueous solution of ferric ions. Iron nanoparticles prepared from microemulsion were deposited on aluminum by electrophoretic method, and their reaction kinetics was compared to that of the same nanoparticles suspended in aqueous batch reaction. With an approximation of pseudo-first-order reaction, rate constants for suspended nanoparticles prepared from microemulsion and dilute aqueous solution were $3.49{\times}10^{-2}min^{-1}$ and $1.40{\times}10^{-2}min^{-1}$, respectively. Iron nanoparticles supported on aluminum showed ca. 30% less reaction rate in comparison with the identical nanoparticles in suspended state. However, supported nanoparticles showed the superior effectiveness in terms of nitrate-nitrogen removal per zero-valent iron input especially when excess amounts of nitrates were present. Iron nanoparticles deposited on aluminum maintained reductive reactivity for more than 3 hours, and produced nitrogen gas as a final reduction product of nitrate-nitrogen.

• Journal of Ginseng Research
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• v.20 no.1
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• pp.49-53
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• 1996

The purpose of this study was to analyze the electrophoretic patterns of soluble proteins from ginseng roots and to compare the protein patterns from Korean ginseng and American quinquefolium. The size difference was found in the major protein bands of a molecular weight of about 27,000 between Korean ginseng and American quinquefolium. The protein band of a molecular weight of 22,000 showed a quantitative difference in its amount. The major 27 K proteins appeared to form a complex heterodimer of 66,000 and to have internal bisulfide bonds, from band shifting studies under non-denaturing conditions. Three peaks appeared when the protein extract from root homogenates was purified using gel filtration and DEAE ion exchange chromatography. The examination of physiological activity and further purification of these fractions are underway.

• Korean Journal of Microbiology
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• v.12 no.3
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• pp.138-146
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• 1974

Taxonomic relations among three species of some edible fleshy fungi(Lentinus edodes, Pleurotus ostreatus, Flammulina velutipes) in the family Tricholomataceae were examined by using polyacrylamied gel disc electrophoresis. The soluble, crude extract of mycelium grown on potato sucrose broth was subjected to electrophoresis. Similarities in the protein bands for each isolated of one species were compared with those for others. In the banding patterns there was a closer relationship between isolates within one species than among isolates of different species. However, the isozyme patterns obtained from each isolate of Peurotus ostreatus (esterase, peroxidase, tyrosinase) were appeared to represent the degree of geographical variability within one species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.292-298
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• 1999

Myofibril and actomyosin were prepared from red muscle and white muscle of fresh water fish and sea water fish, and their biochemical characteristics and SDS PAGE patterns of myofibril were compared. SDS PAGE analysis showed that electrophoretic patterns of myofibril were similar be tween white muscle and red muscle, while difference of 30kDa component of myofibril was detected between fresh water fish and sea water fish. When myofibril were treated with trypsin, difference in hydrolysis of heavy chain was observed between white muscle and red muscle. In activities of Ca ATPase, Mg ATPase, EDTA ATPase and ATPase activity pH curve, myofibrillar protein from fresh water fish showed higher specific activity than those from sea water fish.