• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1231-1236
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• 1996

The electrode resistance of semiconducting PTC BaTiO3 ceramic material was studied in some detail. Comme-rical In-Ag paste In-Ga alloy and electroless plated Ni as well as evaporated Al were chosen as electrode. The contact resistance of electroded samples were measured by both dc resistivity and ac impedance analysis. The aging effect on contact resistance under cyclic loading from -1$0^{\circ}C$ to 85$^{\circ}C$ was also monitored for the prolonged period of time. In case of Al electroded samples the heat treatment and protective coating had effects on the stability against contact resistance degradation. It was also found that the samples with commercial In-Ag paste and electroless plated Ni electrode had good properties of contact resistance against aging.

• Journal of the Semiconductor & Display Technology
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• v.11 no.3
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• pp.63-67
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• 2012

The films were deposited at evaporator system and were annealed at heat treatment. The films had a dense microstructure with fine grains. The electrical properties of the films were dramatically controlled with annealing. Samples Preparation were analyzed in term of positive temperature coefficient of Resistivity Samples were made in the substrate tempera-true of $400^{\circ}C$ deposition time of 10 hours, and forward power of 210watt. R-T(resistivity-temperature) Characteristics of the samples were investigated as a function of the substrate type and the ambient temperature. The resistivity of the thin film specimens was compared with that of the bulk type specimens. By using RF/DC magnetron sputtering system, we obtained lower resistivity in the thermistor with thin $BaTiO_3$ film than that in the bulk type thermistor.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.477-481
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• 2004

In bean sprout culture water imbibition and benzyladenopurine (BA) treatment are done at the same time. The study was carried out to check the effect of treatment period (3, 5, and 7 hours) on growth of mungbean (cv. Keumseongnogdu, Owoolnogdu, and Zhong Lu 1) sprouts and to analyse its absorption amount on the base of their moisture content. The 3 cultivar seeds were soaked in 50 ppm BA solution immediately before 3 hour aeration and then cultured for 6 days. The sprouts were sorted by 4 categories on the base of hypocotyl length; > 7cm, 4 to 7cm < 4cm, and non-germination, and their morphological characters, fresh and dry weights were measured. The cultivar Zhong Lu 1 had the highest rate in longer than 7cm hypocotyls of the three cultivars but the lowest one in shorter than 4cm. Rates of the above 4 categories in cv. Keumseongnogdu, Owoolnogdu showed no significant difference between the treatment periods while one of longer than 7cm hypocotyls in cv. Zhong Lu1 was decreased with longer treatment period. Lateral roots were less formed with longer treatment period, especially as lengthened from 3 to 5 hours. Hypocotyl and root were also lengthened with longer treatment period and hypocotyl was more thickened in 5 hour treatment period than in the two others. Total fresh and dry weights per sprout showed no significant difference between treatment periods although cv. Zhong Lu1 relatively faster grew than the other cultivars. In the case of shorter than 5hour treatment periods the absorption amount of BA was the greatest in cv. Zhong Lu1 but in 7 hour treatment period it was the greatest in cv. Keumseongnogdu and Zhong Lu 1.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.141-147
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• 2012

Biogenic amines have been used as chemical indicators to estimate bacterial spoilage of foods, particularly fish and fish products, cheese, and fermented foods. So far many chromatography methods have been developed to detect biogenic amines in foods. Although these instrumental analyses exhibit good sensitivity, they cannot be used as rapid detection methods due to the chemical treatment of the samples and the time-consuming process involved. For the rapid and simple detection of biogenic amines, enzyme linked immunosorbent assay kits are commercially available. In addition, analytical systems with enzyme-based amperometric biosensor detection have been increasingly developed. The biosensors used to detect the biogenic amines are based on the action of either amine oxidases or amine dehydrogenases that catalyzes the oxidative deamination of biogenic amines to the corresponding aldehydes and ammonia. This review mainly focused on the principle, development, and applications of the detection methods for rapid detection of biogenic amines in foods.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.43-49
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• 1985

This study was conducted to investigate the existance of dormancy in newly collected tubers of Eleocharis kuroguwai Ohwi from paddy fields and to determine the effect of various growth regulators on the bud sprouting and tuberization of E. kuroguwai. The maximum percent sprouting of E. kuroguwai collected at every month during winter was less than 60% regardless of varied collection tunes until 50 days after incubation, suggesting the presence of dormancy in E. kuroguwai tubers. This dormancy was markedly broken as the time went by, probably due to the exposure of tubers the extremly low temperature. The treatment of $BA10^{-3}M$ and $BA10^{-3}+GA10^{-6}M$ increased bud sprouting about 10 and 11 times, respectively, than that of the untreated control indicating that BA seems to be one of the most effective agents among the growth regulators used on the bud sprouting of E. kuroguwai. Foliar application of BA increased tuberization of E. kuroguwai by an average of 34.4% as compared with the untreated control. The highest increase, 39.8% was obtained with BA treatment at $10^{-5}M$.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.456-464
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• 2012

This study was conducted to establish the in vitro optimal condition for seed germination and organogenesis of wild Angelica gigas. The experiment was evaluated the effects of $GA_3$ for pre-treatment with different periods of time (0h, 24h, 48h, 72h) and followed the treatment of seeds by control, scarification and methanol-heating method. As a result, the highest rates (15%) of seed germination was shown under the treatment without soaking of $GA_3$ and methanol-heating treatment. The seed germination was highly increased 60% under the condition of treatment on ultrasonic waves (frequency 80 KHz) with methanol-heating treatment including 0.1 mg/L $GA_3$. The highest callus induction rate was obtained from in vitro germinated stem, root and hypocotyl on the MS medium with 1.0 mg/L NAA and 0.5 mg/L BA. The highest percentages of shooting (50%) and rooting (85%) induction were observed in hypocotyl and root cultured on PGRs free medium and 0.1 mg/L NAA, respectively. In addition, somatic embryogenesis was observed from stem (1.0 mg/L 2,4-D) and hypocotyl (0.1 mg/L NAA).

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.772-777
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• 1999

$Y_2Ba_1Cu_1O_5(Y211)$ powders were prepared by pyrophoric synthesis method and by solid state reaction method using $Y_2O_3(99.9%)$, $BaCO_3(99.9%)$, and CuO(99.9%) powders in both of these processes. The phase formation and reaction kinetics of $Y_2Ba_1Cu_1O_5$ powders have been studied using X-ray diffraction analysis(XRD) of samples at various heat treatment temperatures and reaction time. The reaction characterization suggested that the phase formation rate is mainly controlled by the particle size of Y211 powders. The activation energy(${\Delta}E_a$) of Y211 phase formation in this pyrophoric synthesis method was found to be 136.42 kJ/mol compared with 149.46 kJ/mol for that of solid state reaction method. These results data showed that the pyrophoric synthesis method is kineticaly more efficient than the solid state reaction method in this $Y_2Ba_1Cu_1O_5$ system.

• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.811-815
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• 1997

The present work describes the effect of dry grinding of a mixture composed of $Y_2O_3$, $BaCO_3$ and CuO powders with a planetary ball mill before heat treatment on crystal structure and superconductivity in the $YBa_2Cu_3O_{7-y}$. The specific surface area of the ground product of mixture decreased with an increase in the grinding time, after showing an upward trend up to 60 minutes of grinding. The critical current density, which was influenced by the grinding time of mixture, indicates the maximum value of about $150A/cm^2$ in the case of 60 minutes grinding, while the critical temperature, which were around 90K, for the sintered bodies were almost independent of the grinding time.

• Korean Journal of Materials Research
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• v.4 no.8
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• pp.870-876
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• 1994

In order to investigate the growth behavior of $Y_{2}Ba_{1}Cu_{1}O_{5}$(211) particles in $Y_{1}Ba_{2}Cu_{3}O_{7-\delta}$(123), 123 samples were quenched in air after heat treatment on polycrystal and single crystal MgO substrates at $1100^{\circ}C$ for various periods. 211 grains grew with the increase in holding time. The growth of 211 grains was faster on the polycrystal MgO substrate than on the single crystal MgO substrate. In the samples with the compositions of 211+xCuO($0.2\le X \le 0.8$), the growth rate of 211 grains increased with the increase in CuO content. In the sample with x=0.6 the largest 211 grains were observed. 211 grains in the $Y_{2}Ba_{1}Cu_{1.8}Sn_{0.1}O_{5+\delta}$ samples were distributed very finely and homogeneously. The retarding effect of $SnO_2$ addition on the growth of 211 grain appeared more pronounced in a CuO melt than in a $BaCuO_{2}$+ CuO melt.

• Progress in Superconductivity and Cryogenics
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• v.16 no.1
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• pp.6-8
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• 2014

The influence of quenching temperature, heating atmosphere and annealing time on superconducting characteristics has been studied for $LuBa_2Cu_3O_{7-z}$ compound which has been recently synthesized in a nearly phase-pure form. Resistivity measurements for the as-prepared sample heated at $300^{\circ}C$ in oxygen and subsequently quenched into liquid nitrogen revealed that there is no significant change in $T_c$. On the other hand, $T_c$ of the sample slightly increased when the sample was heated at $300^{\circ}C$ either in air or in $N_2$ atmosphere. It was also found that $T_c$ of the sample decreased when the annealing temperature in $N_2$ atmosphere increased above $400^{\circ}C$. The experimental results indicated that the as-prepared sample is under overdoped state. The enhanced superconducting transition observed in the samples after heating at $300^{\circ}C$ in air or $N_2$ atmosphere was discussed in conjunction with a slight removal of oxygen and ordering of oxygen atoms in the as-prepared sample.