• Title/Summary/Keyword: UV resistance

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Purification and Characterization of Catalase-2 from Deinococcus radiophilus

  • Oh, Kyung-A;Lee, Young-Nam
    • BMB Reports
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    • v.31 no.2
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    • pp.144-148
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    • 1998
  • A bifunctional catalase-peroxidase, designated catalase-2, of a UV resistant Deinococcus radiophilus was purified to electrophoretic homogeneity by both chromatographic and electrophoretic methods. Its molecular weight was 310 kDa and composed of a tetramer of 80 kDa subunits. The catalase-2 exerted its optimal activity at $30^{\circ}C$ and around pH 9. Its $K_m$ value for $H_{2}0_{2} $ was about 10 mM. It showed the typical ferric heme spectrum with maximum absorption at 403 nm which shifted to 419 nm in the presence of cyanide. The ratio of A40i' A2S0 was 0.48. Fifty percent inhibition of the enzyme activity was observed at $4.6{\times}10^{-6}$, $7.7{\times}10^{-6}$, and $3.0{\times}10^{-6}$ M of NaCN, $NaN_3$, and $NH_{2}OH$, respectively. The enzyme was thermostable and not sensitive to 3-amino-1,2,4-triazole. Treatment of the enzyme with ethanol-chloroform caused a partial loss (30%) of its activity. The catalase-2 was distinct from the Deinococcal bifunctional catalase-3 in a number of properties, particularly in its molecular structure and substrate affinity.

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Screening and Characteristics of a Mutant of Actinoplanes teichomyceticus ATCC31121 Highly Producing Teicoplanin (Teicoplanin 생산성이 우수한 Actinoplanes teichomyceticus ATCC31121 변이주 선별 및 배양학적 특성)

  • 노용택
    • Korean Journal of Microbiology
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    • v.37 no.4
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    • pp.299-304
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    • 2001
  • Teicoplanin is a kind of glycopeptide antibiotics produced by Actinoplanes teichomyceticus, and used in the clinical antibiotic such as vancomycin against methicillin-resistant Stabphylococcus aureus (MRSA). Actino planes teichomyceticus ATCC 31121 was mutated with UV to obtain a superior mutant strain with increased level of teicoplanin production. In this investigation, lethal curve was obtained and the optimal condition to induce mutagenesis was determined to isolate the desirable mutant strain. It was also confirmed that teicoplanin activities by agar diffusion method was compared with the parent strain. One mutant strain, T991014-1 with the highest productivity, was finally selected, and was characterized through the various tests such as amylase activity, protease activity, halotolerance, antibiotic resistance, autotoxicity, and productivity. Ad fermentation characteristics of the mutant strain were also studied.

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The Qualitative Study on Outdoor Sportswear Purchase Behavior -Focusing on Functional Fabric Awareness Level and Benefits Sought- (아웃도어 스포츠웨어 구매행동에 관한 질적 연구 -기능성 인지수준과 추구 혜택을 중심으로-)

  • Rhee, Young-Ju;Lee, Eun-Ok
    • The Research Journal of the Costume Culture
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    • v.19 no.5
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    • pp.1088-1101
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    • 2011
  • The purpose of this study was to examine the outdoor sportswear purchase behavior, outdoorwear sportswear brand preference, functional fabric awareness, and benefits sought. The research was performed through in-depth interview during February to March 2011. Data were collected from 10 consumers who had purchased outdoor sportswear and experienced camping in 6 months. First, the results from study showed that functionality/comfortability, design, color, and brand name were important factors in selecting outdoor sportswear. Offline stores were the main place to purchase, however, internet shopping mall and portal online community were another shopping channel as well. Second, respondents preferred imported outdoor sportswear brand to national brand. According to the study, the respondents trusted the imported outdoor sportswear quality based on the brand name, value, and brand history more than national brand. Third, consumers who had low functional fabric awareness were more likely to evaluate apparel products based on the brand name. Knowledge levels for textile functions were high in elastic, UV protection, air permeable, and antibacterial properties. The essential features for camping were water absorbing and quick dry, water resistance, wind proof, UV protection, and fire retardant properties. Finally the results showed that there were two sportswear benefit soughts: functionality and status ostentation.

Phytogenic silver nanoparticles (Alstonia scholaris) incorporated with epoxy coating on PVC materials and their biofilm degradation studies

  • Supraja, Nookala;Tollamadugu, Naga Venkata Krishna Vara Prasad;Adam, S.
    • Advances in nano research
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    • v.4 no.4
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    • pp.281-294
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    • 2016
  • The advantages of nano-scale materials (size 1-99 nm in at least in one dimension) could be realized with their potential applications in diversified avenues. Herein, we report for the first time on the successful synthesis of homogeneous epoxy coatings containing phytogenic silver nanoparticles (Ag) on PVC and glass substrates by room-temperature curing of fully mixed epoxy slurry diluted by acetone. Alstonia scholaris bark extract was used to reduce and stabilize the silver ions. The surface morphology and mechanical properties of these coatings were characterized using the techniques like, UV-Vis (UV-Visible) spectrophotometry, X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FT-IR), Epifluorescence microscopy and scanning electron microscopy (SEM). The effect of incorporating Ag nanoparticles on the biofilm (scale) resistant epoxy-coated PVC was investigated by total viable counts ($CFU/cm^2$) from epoxy coating from (Initial) $1^{st}$ day to $25^{th}$ days. The phytogenic Ag nanoparticles were found to be significantly improving the microstructure of the coating matrix and thus enhanced the anti-biofilm performance of the epoxy coating. In addition, the antimicrobial mechanism of Ag nanoparticles played an important role in improving the anti-biofilm performance of these epoxy coatings.

A Development on the Non-Photomask Plate Making Technology for Screen Printing (III) (포토마스크가 필요 없는 스크린 제판 기술 개발(III))

  • Kang, Hyo-Jin;Park, Kyoung-Jin;Kim, Sung-Bin;Nam, Su-Yong;Ahn, Byung-Hyun
    • Journal of the Korean Graphic Arts Communication Society
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    • v.26 no.2
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    • pp.55-64
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    • 2008
  • We designed a UV-LED exposure system which has 365nm dominant wavelength due to the environment-friendly and economical maskless screen plate making. And the photoresist applied on the screen stretched was exposed without mask by beam projector with UV-LED light source. Then it was developed by air spray with $1.7\;kgf/cm^2$ of injection pressure. The pencil hardness and solvent resistance of curing photoresist film were excellent as those of conventional photoresist film and the maximum resolution of line image formed by maskless screen plate making. was $100{\mu}m$, so we could establish the possibility of environment-friendly maskless screen plate making technology. But the sharpness of the patterns were ${\pm}40{\mu}m$ since the exposure system for maskless plate making has weak light intensity and the diffusion of light.

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Synthesis and Properties of Blue Emitting Polymers Containing Carbazole Groups

  • Kwon, Young-Hwan;Wang, Hui;Kim, Yeon-Bo;Ryu, Jeong-Tak;Chang, Seung-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.473-474
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    • 2005
  • Blue-emitting polymers containing carbazole units In main chains were synthesized by palladium catalyzed polycondensation of aniline with dibromo-substituted monomers such as 3,6-dibromocarbazole, N-(2-ethylhexyl)-3,6-dibromocarbazole, and bis[6-bromo-N-(2-ethylhexyl)-carbazole-3-yl], respectively. All synthesized polymers exhibited relatively good solubility in common organic solvents, considerable molecular weights and high resistance to thermal degradation. From UV-Vis absorption and photoluminescence (PL) spectra of these solution-processable polymers, $\lambda_{max,UV}$ were in the range of 290 ~ 340 nm and $\lambda_{max,PL}$ were in the blue emission range of 440 ~ 478 nm, The polymers had HOMO energy (-5.19 ~ -5.64 eV) and wide band gap energy (2,91 - 3.42 eV).

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Preparation of UV-Curable Polyurethane Modified $Acrylate/SiO_2$ Hybrid Film Using Sol-Gel Process (졸-젤 공정을 이용한 광경화형 폴리우레탄 변형 아크릴레이트/실리카 하이브리드 필름의 제조)

  • Nam, Dae-Woo;Nam, Byeong-Uk;Cha, Bong-Jun;Kim, Baek-Jin
    • Polymer(Korea)
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    • v.31 no.2
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    • pp.111-116
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    • 2007
  • Polyurethane modified acrylate $(PUA)/SiO_2$ hybrid films were prepared by ultraviolet curing and their surface properties were investigated by hardness and adhesion test. The films were examined by the manipulation of mole-ratio of organic to inorganic components. Under the silica content controlled, highly desirable films were achieved and scratch resistance and hardness property of film were also enhanced, which indicates that the crosslinked silica particles are homogeneously dispersed within PUA film.

Roll-to-roll process for large-area transfer of Ag nanowire electrode (은 나노 와이어 전극의 대면적 전사를 위한 롤 투 롤 공정)

  • Park, Yangkyu;Kim, Jae Pil;Kim, Wan Ho;Jung, Kang;Jeong, Ho-Jung
    • Journal of Surface Science and Engineering
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    • v.55 no.3
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    • pp.173-179
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    • 2022
  • This study presents a roll-to-roll process which is capable of Ag nanowire (AgNW) transfer from polyethylene terephthalate (PET) film to polycarbonate (PC) film. We developed a roll-to-roll machine that consists of two film suppliers, a coater of photo-curable resin, a film laminator, an ultraviolet (UV) exposure unit, and a film winder to facilitate large-area electrode transfer between different flexible substates. Using the process, optimal fabrication condition was investigated by parametric experiments in terms of the UV exposure time, number of thermal cycling, and exposure time of high temperature and humidity. A fabricated AgNW on PC film showed sheet resistance of 52 Ω/sq and optical transmittance of approximately 80 % over a range of visible light.

Synthesis and Property of Colorless Polyimide and Its Nanocomposite for Plastic Display Substrate (유연성 디스플레이 기판 소재용 투명성 폴리이미드의 합성 및 그의 나노복합화에 대한 연구)

  • Ma Seung Lac;Kim Yong Seok;Lee Jae Heung;Kim Jung Su;Kim Insun;Won Jong Chan
    • Polymer(Korea)
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    • v.29 no.2
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    • pp.204-210
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    • 2005
  • We describe a colorless, transparent polyimide films for plastic display substrate which should have heat resistance, roll-to-roll processability and low CTE (coefficient of thermal expansion) property. Colorless polyimides were synthesized from 3,3',4,4'-oxydiphthalic anhydride (ODPA) 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and diamines such as sulfonyldianiline, aminophenoxybenzene (TPE-p, TPE-q, TPE-r) and bis[4-(3-aminophen oxy)phenyl] sulfone (m-BAPS). Their optical properties were measured by UV spectrophotometer, colormeter and hazemeter. We prepared polyimide/organophilic layered silicate nanocomposite to improve dimension stability. These colorless polyimide films showed UV transmittance by the level upper $89\%$, at 440 nm and excellent optical property having the value under yellow index (YI)=7. In addition, polyimide nanocomposite films also showed an improvement of CTE value as decreased according to the amount of layered silicate contents.

A Study on the Manufacture and Application of UV-Cured Multi-Functional(Anti-Stain/Virus) Coating Compounds for PVC Tile (PVC 바닥상재용 광경화형 복합기능(내오염/항균)성 코팅액의 제조 및 응용에 관한 연구)

  • Yoon, Hyun-Jung;Park, Bo-Ram;Ha, Jin-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3615-3620
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    • 2010
  • This study is development of UV-cured coating compounds which has more improved anti-stain and anti-biosis, about surface prevention of PVC Tile. We added water-soluble anti-static and anti-microbial agent to the resin. The process has prevented electrostatic and bacterial contagious disease. The result, which added 15wt% of water-soluble anti-static and 1wt% anti-microbial agent and coated with No.12 Bar-coater, coating composition had optimum surface property. It appear electric resistance($10^9{\Omega}/cm^2$), anti-stain (Ink Test, Dust Test), anti-biosis (99.99%), and adhesive power(100%).