• The Plant Pathology Journal
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• 제24권4호
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• pp.423-432
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• 2008

The difference of carbon source utilization and fatty acid composition between the pathotypes of Xanthomonas strains, which causing citrus bacterial canker was compared, and the physiochemical characteristics were used to analyze relationship of the strains for the first time. The pattern of several carbon sources utilization and fatty acids composition reliably discriminated the pathotypes of Xanthomonas strains. The dendrogram which was constructed by 95 carbon source utilization profiles differentiated X. axonopodis pv. citri A, $A^*$ and $A^w$ from the other pathotypes. When the dendrogram was drawn by combined analysis of carbon source utilization pattern and fatty acid composition, X. axonopodis pv. aurantifolii B, C and X. axonopodis pv. citrumelo formed a distinct cluster. The difference of carbon source utilization and fatty acid composition could be used effectively for the identification of pathotypes of citrus bacterial canker. The physiochemical characteristics strongly indicated that the strains isolated in Korea belong to X. axonopodis pv. citri A type. The cluster analysis by the band patterns of ERIC-, BOX- and REP-PCR allowed the discrimination of the pathotypes isolated from Korea. However, the rep-PCRs could not differentiate X. axonopodis pv. citri A types from $A^*$ and $A^w$ types. The overall results of metabolic profiles and rep-PCRs strongly indicated that the Korean isolates are X. axonopodis pv. citri A type.

• Applied Science and Convergence Technology
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• 제26권2호
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• pp.34-41
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• 2017

A 2.45 GHz microwave plasma with linear antenna has been prepared for hydrophobic and wear-resistible surface coating of carbon steel. Wear-resistible properties are required for the surface protection of cutting tools and achieved by depositing a hydrogenated amorphous carbon film on steel surface through linear microwave plasma source that has $TE_{10}-TEM$ waveguide. Compared to the existing RF plasma source driven by 13.56 MHz, linear microwave plasma source can easily generate high density plasma and provide faster deposition rate and wider process windows. In this study, $Ar/CH_4$ gas mixtures are used for hydrogenated amorphous carbon film deposition. When microwave power of 1000 W is applied, 40 cm long uniform $Ar/CH_4$ plasma could be obtained in gas pressure of 200~400 mTorr. The Vickers hardness measurement of hydrogenated amorphous carbon film on steel surface was evaluated. It was found the optimized deposition condition at $Ar:CH_4=25:25$ sccm, 300 mTorr with microwave power of 1000W and RF bias power of 100W. By deposition of hydrogenated amorphous carbon film, contact angle on steel surfaces increases from $43.9^{\circ}$ to $93.2^{\circ}$.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.374-377
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• 2000

본 연구에 사용한 Pseudomonas sp. BCNU 154는 Gram 음성 toluene 내성세균으로 형태적${\cdot}$생리적 특성을 비교하여 보았을 때 Pseudomonas 속임이 확인되었다. 폭넓은 유기용매에 대한 내성한계를 가지고 있으며 Pseudomonas sp. BCNU 154 toluene 내성균주는 Modified Luria-Bertani(LBM) 배지에서 잘 자랐으며, $30^{\circ}C$에서 최적의 생육상태를 나타내었다. 최적 pH는 6에서 7로 나타났으며 1%의 toluene을 첨가하였을 경우에는 pH 2에서 8에 이르는 넓은 pH대에서 잘 자랐으며, cumene은 pH 6에서 10까지의 범위에서 좋은 성장을 보였다. Pseudomonas sp. BCNU 154 균주의 toluene, ethylbenzene, ${\rho}$ -xylene, cumene분해는 $1g/{\ell}$의 농도로 첨가시 toluene의 경우 97%이상이 분해되었고, ${\rho}$은 92%, ethylbenzene은 80%이며, cumene은 90% 이상이 분해되는 것으로 나타났다. 따라서 각 유기용매에 대해 대체로 12시간 내에 90%이상의 분해가 이루어졌으며, ethylbenzene의 경우에는 성장곡선과 마찬가지로 일정시간이 지난 후 성장과 분해가 둔화되다가 다시 성장과 분해가 일어나는 현상을 보였다.

• Journal of Microbiology and Biotechnology
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• 제6권5호
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• pp.315-320
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• 1996

The role of glyoxylate bypass in a lysine-producing Corynebacterium lactofermentum strain was analyzed. Unlike the wild type, the strain expressed enzymes of glyoxylate bypass during growth in the fermentation broth containing glucose as the carbon source. To evaluate the importance of glyoxylate bypass in the strain, we disrupted chromosomal aceA by using a cloned fragment of the gene. Site-specific disruption of aceA which codes for the isocitrate lyase, the first enzyme of the bypass, was confirmed by Southern blot analysis. The aceA mutant strain completely lost isocitrate lyase activity and ability to grow in a minimal medium containing acetate as the sole carbon source. The mutant strain was similar to its parental strain in growth characteristics and produced comparable amounts of lysine in shake flasks containing glucose as the carbon source. The amount of oxaloacetate accumulated in the fermentation medium was similar for both strains, suggesting that expression of glyoxylate bypass does not necessarily lead to the increase in intracellular oxaloacetate. These data clearly demonstrate that glyoxylate bypass does not function as one of the routes of carbon supply for lysine production in the strain. It appears that the leakiness of the glyoxylate bypass in the strain might be the result of a secondary mutation which arose during previous strain development by random mutagenesis.

• 한국식물병리학회지
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• 제1권1호
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• pp.56-60
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• 1985

본 실험은 질소 및 탄소원이 Cercospora kikuchii 균사생장에 미치는 영향과 여러 배양조건에서 생장한 C. kikuchii가 세균생장을 저지하는 정도를 알아보았다. C. kikuchii 균사생장에 적합한 질소원은 yeastextract였고, 탄소원으로는 sucrose, glucose, maltose, fructose를 첨가하였을 때 균사생장이 좋았다. C. kikuchii의 세균생장저지 실험에서 wild type은 pH 조건은 5.0에서, 질소원으로는 yeast-extract 또는 peptone.을 첨가하였을 때, 탄소원으로는 sucrose, maltose, glucose, fructose를 첨가한 배지에서 생장하였을 때 Erwinia carotovora와 Pseudomonas solanacearum의 생장을 크게 저지시켰다. 그러나 albino 돌연변이균주는 실허된 세균의 생장을 거의 저지시키지 못하였다.

• 한국세라믹학회지
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• 제35권3호
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• pp.231-238
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• 1998

Cr3C2 -dispersed TiC composites were prepared via HPCS(high pressure-self combustion sintering) pro-cess using mixtures of Ti, Cr and a carbon source for the purpose of increasing the facture toughness and sinterability of TiC. In this study the microstructure and properties of the composites were investigated in terms of relation to the carbon source the particle size of Ti and the amount of Cr. It was found that car-bon black was the most effective carbon source among the various carbon sources tested and the reaction was more effective as the particle size of Ti decreased. Among the sintered composites of Ti-C-Cr system the one with 30wt% Cr showed the best physical properties with 0.5% in apparent porosity 98.8% in re-lative density 18.2 GPa in hardness and 4.46 MPa.m1/2 in fracture toughness. In addition it was observed that the lattice constant of TiC decreased gradually with increasing the amount of Cr.

• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1101-1108
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• 2011

The rise in global energy demand has prompted researches on developing strategies for transforming coal into a cleaner fuel. This requires isolation of microbes with the capability to degrade complex coal into simpler substrates to support methanogenesis in the coal beds. In this study, aerobic bacteria were isolated from an Indian coal bed that can solubilize and utilize coal as the sole source of carbon. The six bacterial isolates capable of growing on coal agar medium were identified on the basis of their 16S rRNA gene sequences, which clustered into two groups; Group I isolates belonged to the genus Rhizobium, whereas Group II isolates were identified as Chelatococcus species. Out of the 4 methods of whole genome fingerprinting (ERIC-PCR, REP-PCR, BOX-PCR, and RAPD), REP-PCR showed maximum differentiation among strains within each group. Only Chelatococcus strains showed the ability to solubilize and utilize coal as the sole source of carbon. On the basis of 16S rRNA gene sequence and the ability to utilize different carbon sources, the Chelatococcus strains showed maximum similarity to C. daeguensis. This is the first report showing occurrence of Rhizobium and Chelatococcus strains in an Indian coal bed, and the ability of Chelatococcus isolates to solubilize and utilize coal as a sole source of carbon for their growth.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.74-74
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• 2009

The ArF PR mask was. developed to overcome the limit. of sub 40nm patterning technology with KrF PR. But ArF PR difficult to meet the required PR selectivity by thin PR thickness. So need to the multi-stack mask such as amorphous carbon layer (ACL). Generally capacitively coupled plasma (CCP) etcher difficult to make the high density plasma and inductively coupled plasma (ICP) type etcher is more suitable for multi stack mask etching. Hybrid Coupled Plasma source (HCPs) etcher using the 13.56MHz RF power for ICP source and 2MHz and 27.12MHz for bias power was adopted to improve the process capability and controllability of ion density and energy independently. In the study, the oxide trench which has the multi stack layer process was investigated with the HCPs etcher (iGeminus-600 model DMS Corporation). The results were analyzed by scanning electron microscope (SEM) and it was found that etching characteristic of oxide trench profile depend on the multi-stack mask.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.352-355
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• 2000

Production of pullulan by Aureobasidium pullulans HP-2001 with agro-industrial byproducts was investigated. Agro-industrial byproducts from the rice processing industry for the traditional Korean food (AIB-A), apple juice production (AIB-B), and soybean sauce production (AIB-C) were used for carbon and nitrogen source for production of pullulan. Major components of AIB-A were glucose, maltose, maltotriose, and dextran. AIB-A and B were found to be good substitute to glucose as carbon source. Productivity of pullulan with AIB-A and B as carbon source was similar to that glucose. Molecular weight of pullulan produced with AIB-A and B was higher than that with glucose. Major components of AIB-B and C were carbohydrate, protein, fat and ash. AIB-C was also a good substitute to yeast extract as nitrogen source. Some of physiological conditions were examined for the large scale production of pullulan.

• 한국표면공학회지
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• 제44권5호
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• pp.190-195
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• 2011

Diamond-like carbon (DLC) has many outstanding properties such as low friction, high wear resistance and corrosion resistance. However, it is difficult to achieve enough adhesion on the metal substrates because of weak bonding between DLC film and the metal substrate. The purpose of this study is to enhance an adhesion of DLC film. For improving adhesion, the substrate was treated by active screen plasma nitriding before DLC film deposing. Nitrided substrates were investigated by Glow Discharge Spectrometer (GDS), Micro-Vickers Hardness. DLC films were deposited on several metals by linear ion source, and characteristics of the films were investigated using nano-indentation, Field Emission Scanning Electron Microscope (FESEM). The adhesion was measured by scratch tester. The adhesion of DLC films was increased when nitriding layer was formed before DLC deposition. Therefore, the adhesion of DLC film can be enhanced as increasing the hardness of materials.