• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.76-80
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• 2010

In this study, YDC powders with uniform composition and particle size were synthesized by a citrate method and their thin film deposition was conducted by electrospray deposition method. Polymeric precursor was prepared first by reaction of metal salts with citrate acid and ethylene glycol. Fluorite crystalline YDC powders were obtained by calcining the precursor at $750^{\circ}C$ for 3 h. The electrospray deposited films prepared at the optimum conditions became dense and defect-free after heat treatment at $1400^{\circ}C$ for 3 h. The film thickness was linearly varied with the deposition time.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.798-803
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• 2003

In synthesis of nano powders, the hard agglomeration for the synthesized powders occurred during the drying processing. In order to avoid hard agglomeration in particles the freeze drying process was used in this experiment. e fabricated the Yttira-Doped Ceria(YDC) nano powder by co-precipitation. Starting materials used in experiments were the cerium(III) nitrate and yttrium(III) nitrate solution with 야-water, which two solutions were mixed and then the precipitated hydroxides were prepared for adding sodium hydroxide. The co-precipitated powders were dried by the thermal drying at 8$0^{\circ}C$ for 24 h and by freeze drying at -4$0^{\circ}C$, 30 mtorr for 72 h. The lattice parameter and crystallite size as a function of calcination temperature was characterized by XRD analysis. The lattice parameter of YDC was decreased with addition amount of yttrium and was estimated as 5.401683 $\AA$ at $700^{\circ}C$. Crystallite size were calculated by XRD-LB method, and morphologies were confirmed with the observation of TEM and SEM. The freeze dried YDC powders had medium diameter of 17 nm with more uniform size distribution than the thermal dried YDC posers, which were mainly ascribed to the difference of agglomerates formation during drying stage.

• Journal of the Korean Ceramic Society
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• v.36 no.4
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• pp.391-402
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• 1999

Characteristics of composite electrolytes which were prepared by coating a thin film of YSZ (yttria sta-bilized zirconia : (ZrO2)0.92 (Y2O3)0.08) on YDC (yttria doped ceria : Ce0.8Y0.2O1.9) with mixed conductivity have been investigated in order to develop the low-temperature solid oxide fuel cell. The thickness (t) of spin-coated YSZ thin films after the heat-treatment at 600$^{\circ}C$ was increased proportionally to the sol con-centrations (C) while the decrease in its thickness with the spin rate ($\omega$) could be expressed in the e-quation of ln t=9.49-0.53 ln $\omega$(0.99mol//s sol conc.) When the sol concentration and the spin rate being less than 0.99 mol/l and higher than 1000 rpm respectively reliable YSZ/YDC composite electrolytes could be obtained by multi-coating although several micro-cracks were observed in singly coated YSZ film surfaces. The dense YSZ film with a 1$\mu\textrm{m}$ thickness was prepared by coating of 0.99 mol/l YSZ sol five-times at 2000 rpm followed by heat-treatment at 1400$^{\circ}C$ for 2h, The adhesion between YSZ film and YDC substrate was found to be very good. The open circuit voltages of H2/O2 single cell with YSZ/YDC composite electrolytes were 0.79∼0.82 V at 800$^{\circ}C$ and 0.75∼0.77V at 900$^{\circ}C$ The open circuit voltage was inversely proportioned to the thickness ratio of YSZ thin film (1$\mu\textrm{m}$) to YDC substrate(0.28-2.22 mm)

• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.154-159
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• 1989

Chromosomal DNA fragments of Bacillus sp. YA-14 isolated from soil as a potent xylan hydrolyzing bacterium, were ligated to a vector plasmid, pBR322, and used to transfer Escherichia coli HB101 cells. The recombinant plasmid pYDC21 was found to enable the transformants to produce xylanase. pYDC21 was found to contain the 3 kb HindIII fragment originated from the Bacillus sp. YA-14 chromosomal DNA by southern hybridization. The optimum temperature and pH for the reaction of xylanse produced by E. coli (pYDC21) were appeared at 50$_7$C and pH 7.0, respectiveiy. the xylanase enzyme was stable between pH 5.0 and 7.0 and maintained stably up to 4$0^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.34 no.10
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• pp.1067-1073
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• 1997

The yttria doped ceria (YDC) thin films were fabricated by electrochemical vapor deposition on the porous $\alpha$-Al2O3 substrate. The growth rates of the films obeyed a parabolic rate law, which constant was 259.0 $m^2$/hr at 120$0^{\circ}C$. As deposition temperature (above 110$0^{\circ}C$) increased, dense thin films were enhanced. Mole fraction of XYC13 had an effect upon surface morphologies. Electrical conductivity was increased with deposition temperature. The conductivity of YDC film prepared at XYC13=7.9$\times$10-2 was about 0.097 S/cm at 104$0^{\circ}C$ and the activation energy of conduction was calculated to be 26.6 kcal/mol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.687-694
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• 2015

The purpose of this study was to evaluate the yield, antioxidant content, and antioxidant activity of adzuki beans according to germination time. Cultivated varieties were Vigna angularis var. Nipponensis cv. Chungju-pat (CJP), and Yeonduchae (YDC), and Vigna radiata (L.) R. Wilczek cv. Dahyeon (DH). The moisture, crude protein, calcium, and magnesium contents of YDC significantly changed with increasing germination time, whereas potassium, natrium, and aluminium contents did not significantly change. Sprout yield, total polyphenol, flavonoid, and tannin contents of ethanolic extracts from adzuki and mung beans significantly increased with increasing germination time. Total polyphenol contents of ungerminated CJP, YDC, and DH were 1.96, 2.68, and 2.02 mg/g, and those of CJP and YDC germinated for 144 h were 3.33 and 3.47 mg/g, respectively. Total flavonoid content of adzuki beans substantially decreased with increasing germination time. Total tannin content substantially increased with increasing germination time, and YDC showed higher contents (0.85 mg/g) sample germinated for 120 h. DPPH radical scavenging activities of CJP and YDC substantially decreased with increasing germination time, whereas that of DH increased. ABTS radical scavenging activities of ungerminated CJP, YDC, and DH were 4.57, 6.51, and 2.82 mg/g, respectively, and increased after germination for 72~120 h.

• KSBB Journal
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• v.24 no.1
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• pp.25-29
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• 2009

Ceramide is important not only for the maintenance of the barrier function of the skin but also for the water-binding capacity of the stratum corneum. Though the effectiveness of ceramide is not understood fully, ceramide has become a widely used ingredient in cosmetic and pharmaceutical industries. However, ceramide production from Saccharomyces cerevisiae has not been widely studied and the quantity are very low. Gene deletion in the cell is used frequently to investigate the function of gene and verification research of drug target. Specially, deletion mutant library is useful for a large amount functional analysis of gene. In this study, deletion mutants of genes on the metabolic pathway of ceramide synthesis in S. cerevisiae were grown in a batch culture and the cellular content of ceramide was measured. The ceramide content was highest in ${\triangle}$ydc1 mutant and 6 mg ceramide/g cell was obtained.

• Research in Plant Disease
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• v.16 no.1
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• pp.97-100
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• 2010

Angular leaf spot of strawberry caused by Xanthomonas fragariae occurred sporadically in the farmers open field at Sugok-myon, Jinju city, and greenhouse at Okjong-myon, Hadong-gun, Gyeongnam province, Korea. Typical symptoms of angular leaf spot initially appeared as a minute, water-soaked, rotted lesion on the lower leaf surface and the minute spots expanded to form angular leaf spots, usually delimited by small veins. The lesion was translucent under the transmitted light and dark green under reflected light. The slow growing pathogen was a gram-negative, motile bacterium with single polar flagellum, and producing yellowish orange pigment on YDC medium. It showed very strong pathogenicity on the leaves of strawberry. On the basis of biological characteristics and pathogenicity test on host plants, the bacteria was identified as a Xanthomonas fragariae. This is the first report on angular leaf spot of strawberry caused by X. fragariae in Korea.

• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.265-270
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• 1995

Transposon mutation of Xanthomonas campestris pv. vesicatoria (Xcv) was induced by using transposon omegon ($\Omega$)-Km (Tn $\Omega$Km), which was confirmed by resistance to kanamycin (KMr), and nonpathogenic mutants were selected through the inoculation test on pepper plants. The mutagenesis frequency was about 6$\times$10-8, and 53 out of 2,000 Kmr bacterial colonies tested were nonpathogenic to the pepper cultivar Cheung-Hong. Optimum conditions for the Tn $\Omega$Km mutagenesis of Xcv were Luria Bertani (LB) broth medium for culture of Xcv, yeast extract-dextrose-CaCO3 (YDC) agar medium for selection of Tn $\Omega$Km-mediated mutants, and over 1 to 2 in the ratio of the donor (Escherichia coli S17-1 with the plasmid pJFF350 $\Omega$Km) and the recipient (Xcv) in the culture for the mutagenesis. One of the 4 nonpathogenic mutants (WNP1, WNP3, WNP4 and WNP5), which had been reconfirmed through the inoculation on pepper cv. Dabokgun, showed no differences in the production of exoenzymes such as protease and polygalacturonase and extracellular polysaccharides in vitro and the bacterial growth rate from those of the wild type of Xcv.

• Research in Plant Disease
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• v.11 no.2
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• pp.146-151
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• 2005

A new bacterial disease of sesame(Sesamum indicum) was observed on field-grown plants in Suwon, Hongchun and Yeonchun in 2000. Leaf symptoms initially appeared as water-soaked spots that gradually enlarged, became necrotic and were often bordered by a small zone of lemon yellow tissue. In the case of severe infection, dead leaves were defoliated. Isolations made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow-pigmented bacterium typical of a xanthomonad. Two bacterial strains were purified and used for farther tests. Pathogenicity of strains was confirmed on 3-week-old sesame plants sprayed with bacterial suspensions containing $10^{8}cfu/ml$ of phosphate buffered saline. The Biolog and fatty acid analyses of the two strains(SL3451 and SL3476) 1mm sesame leaf blight showed that they could be identified as ft campestris pv. sesami because of their high similarity to the tester strain(X. campestris pv. sesami LMG865) with a match probability of $100\%$. The bacterium grew well between 18 and 36$^{\circ}C$, but optimum temperature was $27^{\circ}C$ on LB broth. This is the first report of bacterial blight of sesame in Korea. Symptoms of bacterial blight of sesame are difficult to differentiated with those of bacterial leaf spot caused by Pseudomonas syringae pv. sesami.