• Title/Summary/Keyword: Molecular Characteristics

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Strain Identification and Comparative Analysis of Toxigenic Cyanobacteria Determined by PCR

  • Jung Jong-Mun;Jung Eun-Young;LEE You-Jung;Park Hong-Ki;Jung Mi-Eun;Ji Ki-Won;Joo Gea-Jae
    • Journal of Environmental Science International
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    • v.14 no.7
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    • pp.649-655
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    • 2005
  • Microcystis aeruginosa is common form of cyanobacteria (blue-green algae) capable of producing toxic heptapeptide (microcystin) that cause illness or death. The comparison of molecular genetic method with the morphological characteristics of cyanobacteria was conducted. We have designed PCR primers (JJM98F, JJM1141R) for cyanobacterial 16S rRNA and phycocyanin intergenic spacer (PC-IGS) gene domain. To confirm the production of microcystins, PCR primers for the N-methyltransferase (NMT) domain of microcystin synthetase gene mcyA were designed using 21 cyanobacteria strains Most of isolated strains from the Nakdong River was classified as Microcystis aeruginosa and the similarities were $99\%$ with M. aeruginosa AF 139292. $38.1\%$ of isolated strains contained microcystin synthesis gene. NMT (N-methyltransferase) were not detected in isolated strain in several strains, which means non-toxic. However, the NMTs of the strains were detected during the cultivation.

Liquid Crystal Alignment on Multi-stacked Layer HfO2 Thin Films Using a Solution-process (용액 공정 기반의 다중 적층된 HfO2 박막 상에서의 액정 배향)

  • Kim, Dai-Hyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.11
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    • pp.821-825
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    • 2013
  • Effect of multi-stacked layer (MSL), 0.1 mol (M) and 0.3 mol (M) hafnium oxide ($HfO_2$) alignment layers were fabricated via a solution-process for LCs orientation. The solutions were spin-coated and annealed in a furnace. MSL consists of three sub-layers using 0.1 M solution, mono-layer (ML) is composed of 0.3 M $HfO_2$ solution. Then ion-beam irradiation was treated with 1.8 keV for 2 min. $HfO_2$-based LC cells were investigated through photographs, pre-tilt angle using crystal rotation method, X-ray photoelectron spectroscopy (XPS) measurement, and surface roughness using atomic force microscopy(AFM) for their characteristic research. Good LC orientation characteristics were observed on MSL $HfO_2$ surface. The LC alignment mechanism on MSL $HfO_2$ and ML $HfO_2$ surfaces was attributed to van der Waals (VDW) interaction between the LC molecular and substrate surface.

New polymeric host material for efficient organic electro phosphorescent devices

  • Jung, Choong-Hwa;Park, Moo-Jin;Eom, Jae-Hoon;Shim, Hong-Ku;Lee, Seong-Taek;Yang, Nam-Choul;Liand, Duan;Suh, Min-Chul;Chin, Byung-Doo;Hwang, Do-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.843-845
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    • 2009
  • A polymeric host for triplet emitters composed of N-alkylcarbazole and tetramethylbenzene units was successfully synthesized. Efficient energy transfer was observed between this polymeric host and green phosphorescent dyes. The device fabricated using 5 wt% green 1 in the polymeric host as the emitting layer showed the best performance. Thin films of this host-guest system, exhibiting clear stripe patterns could be prepared through the LITI process. The patterned films were then used to fabricate electrophosphorescent devices, which show performance characteristics similar to those of spin-coated devices. The new host material is a good candidate to be used in polymer-based full-color electrophosphorescent light-emitting displays.

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Simultaneous Removal Characteristics of NOx, SOx from Combustion Gases using Plasma Chemical Reaction (플라즈마 화학반응에 의한 연소가스 중 NOx. SOx 동시제거 특성)

  • 박재윤;고용술;이재동;손성도;박상현;고희석
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.406-409
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    • 1999
  • Experimental Investigations were carried out to remove NOx, SOx simultaneously from simulated flue gas[NO(0.02%)-SO$_2$(0.08%)-$CO_2$-Air-$N_2$] by using a plasma chemical reaction. Ammonia gas(14.81%) balanced by argon was diluted by all and was Introduced to mall simulated flue gas duct through NH$_3$ Injection system which is in downstream of reactor. The NH$_3$ molecular ratio(MR) was determined based on (NH3) to [NO+S0$_2$]. MR is 1, 1.5, 2.5. The NOx removal rate significantly increased with increasing NaOH bubble quantity. The SO$_2$ removal rate was not significantly effected by applied voltage, however it fairly Increased with increasing NH$_3$ molecule ratio. By-product aerosol particle was observed by XRD(X-ray diffraction) after sampling, The NOx, SOx removal rates, when H2O vapour bubbled by dry all was injected to plasma reactor, were better than those of other cases. When aqueous NaOH solution(20%) bubbled by 2.5( ι /min) of $N_2$ and 0.5 ( ι /min) NH$_3$(MR=1.5) were injected to simulated flue gas, The NOx. SOx removal rate was 95 ~ 100[%]

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The surface discharge performance of silicone rubber in the Salt fog test (Salt fog 시험에서 silicone rubber에서 발생하는 방전 전류의 특성)

  • 강성화;박영국;이광우;김완수;이용회
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.565-569
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    • 1999
  • In these days, the silicone insulators have been increasingly studied and applied for outdoor insulators because it has superior characteristics than porcelain and glass insulators, which have been used for outdoor insulators. First of all, The excellent performance of the silicone rubber in polluted and wet conditions is attributed to the ability of the material to maintain the hydrophobicity of the surface in the presence of severe contamination and wet conditions. This is because of the presence of low molecular weight mobile fluid in the silicone rubber which diffuses to the surface and to above the contamination layer. But, the leakage current and some surface discharge occurs on surface of the composite polymeric insulation materials when the insulator is used for a long time with severe contaminative condition and it can lead the contamination flashover. So the leakage current and the discharge current are important to estimate the condition of the silicone rubber surface. In this paper, the average leakage current, the relation of surface discharge current and phase angle were study to investigate electrical conduction of silicone rubber surface with the salt fog condition.

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Isolation of the Exopolysaccharide Producing Enterobacter sp. and Pnysicochemical Properties of the Polysaccharide Produced by This Strain (다당 생성 Enterobacter sp.의 분리 및 생성 다당의 특성)

  • 김대진;이신영
    • KSBB Journal
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    • v.16 no.4
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    • pp.370-375
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    • 2001
  • For the production of new exo-biopolymers from microorganisms, an exe-biopolymer producing bacterial strain was isolated from the composter used in composting of organic wastes. Bacteriological properties of this strain and physicochemical properties of producing exo-biopolymer were investigated. The isolated strain was identified as Enterobacter sp. through its morphological, cultural and physiological characteristics. The results of color reactions, CPC (cetyl pyridinium chloride) precipitation and infra red absorption spectral analysis indicated that this exo-biopolymer was presumed as an acidic polysaccharide with uronic acid. This polysaccharide was identified as hetero-polysaccharide consisting of galactose, mannose and galacturonic acid by gas chromatography, and the molecular weight of exopolysaccharide purified by gel chromatography were about 370,000 daltons. The polysaccharide solutions(0.50-2.0%, w/v) exhibited non-Newtonian flow behavior with pseudoplastic property and showed the ability of gel formation at above 1.5% (w/v) of polysaccharide concentration.

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Development of Thermostable Fusant, CHY1612 for Lignocellulosic Simultaneous Saccharification and Fermentation (섬유질계 동시당화발효를 위한 내열성 융합 효모, Kluyveromyces marxianus CHY1612의 개발)

  • Kang, Hyun-Woo;Kim, Yule;Park, Ju-Yong;Min, Ji-Ho;Choi, Gi-Wook
    • KSBB Journal
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    • v.25 no.6
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    • pp.565-571
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    • 2010
  • To develop thermostable ethanol fermentative yeast strain for lignocellulosic simultaneous saccharification and fermentation, high ethanol producing yeast, Saccharomyces cerevisiae CHY1012 and thermostable yeast, Kluyveromyces marxianus CHY1703 were fused by protoplast fusion. The thermostable fusant, CHY1612 was identified as a Kluyveromyces marxianus by phenotypic and physiological characteristics, as well as molecular analysis based on the D1/D2 domains of the large subunit (26S) rDNA gene and the internally transcribed spacer (ITS) 1 + 2 regions. For lignocellulosic ethanol production, AFEX pretreated barley straw at $150^{\circ}C$ for 90 min was used in a simultaneous saccharification and fermentation (SSF) process using thermotolerant CHY1612. The SSF from 16% pretreated barley straw at $43^{\circ}C$ gave a saccharification ratio of 90.5%, a final ethanol concentration of 38.5 g/L, and a theoretical yield of 91.2%. These results show that K. marxianus CHY1612 has potential for lignocellulosic ethanol production through simultaneous saccharification and fermentation with further development of process.

Syntheses and Characteristics of Polymethine Squarylium and Croconium Dyes (Squarylium, Croconium계 Polymethine 색소의 합성과 특성)

  • Kim, Sung Hoon;Hwang, Seok Hwan;Song, Han Chul;Yoon, Nam Sik
    • Journal of the Korean Chemical Society
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    • v.40 no.12
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    • pp.741-747
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    • 1996
  • The syntheses and absorption spectra of squarylium and croconium dyes were studied. IR data and negative solvatochromism revealed that squarylium dyes have symmetrical 1,3-bonded squarylium rings. A new class of unsymmetrical squarylium dyes and their precursor have also been synthesized. The λmax of croconium dyes undergoes a bathochromic shift of about 100 nm compared with corresponding squarylium dyes. This shift can he calculated by the Pariser-Parr-Pople molecular orbital method.

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Separation and flux characteristics in cross-flow ultrafiltration of bovine serum albumin and bovine hemoglobin solutions

  • Hsiao, Ruey-Chang;Hung, Chia-Lin;Lin, Su-Hsia;Juang, Ruey-Shin
    • Membrane and Water Treatment
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    • v.2 no.2
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    • pp.91-103
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    • 2011
  • The flux behavior in the separation of equimolar bovine serum albumin (BSA) and bovine hemoglobin (HB) in aqueous solutions by cross-flow ultrafiltration (UF) was investigated, in which polyacylonitrile membrane with a molecular weight cut-off (MWCO) of 100 kDa was used. BSA and HB have comparable molar mass (67,000 vs. 68,000) but different isoelectric points (4.7 vs. 7.1). The effects of process variables including solution pH (6.5, 7.1, and 7.5), total protein concentration (1.48 and 7.40 ${\mu}M$), transmembrane pressure (69, 207, and 345 kPa), and solution ionic strength (with or without 0.01 M NaCl) on the separation were examined. It was shown that the ionic strength had a negligible effect on separation performance under the conditions studied. Although BSA and HB are not rigid bodies, the flux decline in the present cross-flow UF did not result from the mechanism of cake filtration with compression. In this regard, the specific cake resistance when pseudo steady-state was reached was evaluated and discussed.

The detection of Human Papillomavirus (HPV) by the polymerase chain reaction(PCR) in head and neck cancers (두경부암에서 중합효소 연쇄반응을 이용한 유두종 바이러스의 검출)

  • ;;;Richard E Hayden;David B Weiner
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1993.05a
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    • pp.87-87
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    • 1993
  • Polymerase chain reaction is widely used as a powerful tool in modern molecular biology. As there is agreement that the HPV is an important factor in the head and neck cancers, the detection of HPV DNA sequence in the head and neck cancer tissue has been tried in several ways. We used the PCR to detect the E1 open reading frames of the HPV in paraffin-embedded tissue of the patients with the head neck cancers. Eleven of the fifty-four tested samples (30%) showed positive result. We have analysed the clinical courses and characteristics related with Human Papillomavirus in those patients.

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