• Title/Summary/Keyword: OZONE RESISTANCE

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Ozone resistance of radiosensitive strains of escherichia coli K-12 (Escherichia coli K-12 방사선 감수성 균주의 오존 내성)

  • Harvey, Michel
    • Korean Journal of Microbiology
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    • v.26 no.2
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    • pp.113-121
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    • 1988
  • Ozone, an atmospheric pollutant, can damage similar UV and X-rays DNA and its components. It is possible then that the KNA damage produced by this gas are similar, to some extent, to those of radiations and that they could be repaired by the same DNA repair mechanisms. It has been observed in Escherichia coli that radiosensitive strains such as lex A, rec A and pol A, all deficient to some extent for DNA repair, are more sensitive to ozone than a wild type strain. We have thendetermined the ozone resistance and host-cell reactivation of ozone-damaged T3 phages for the E. coli double mutants pol A, lex A, uvr B, lex A, uvr A, rec A and rec A lox A. According to the results, the DNA polymerase 1 plays a key role in ozone resistance and Type 11 mechanism and/or shory patch excision repair are the most important for it. The interactions between the different DNA repair mechanisms are secondary. There is a strong correlation between ozone resistance and the capacity to reactivate T3 phages damaged by ozone.

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Experimental Study on Evaluation of Bond Strength after Ozone Treatment and Ozone Resistance of Concrete Metal Spray Coating for Advanced Water Treatment (고도정수처리용 콘크리트 금속용사 피막의 내오존성 및 오존처리 후 부착강도 평가에 관한 실험적 연구)

  • Park, Jin-Ho;Jang, Hyun-O;Lee, Han-Seung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.4
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    • pp.68-75
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    • 2018
  • The introduction of advanced water treatment facilities has increased as the conventional purification method cannot remove the substance clearly. However, the internal waterproofing and Anticorrosion materials of the advanced water treatment facility using ozone deteriorate due to the oxidation power of ozone and affects the concrete, which causes a decrease in durability. This study is to evaluate the ozone resistance according to the type of spray metal and the surface treatment method of the coating, and the bond strength after ozone treatment in order to develope a finishing method to prevent deterioration of concrete structure of water treatment facility using metal spraying method as a way to construct metal panel with excellent ozone resistance and chemical resistance by an easier way than the previous. The Experimental results show that spray metal Ti has superior ozone resistance even after spraying. It is considered to be the most suitable method for ozone resistance and bond performance by finishing using Teflon sealing as surface treatment method.

Effect of Environmental Factors on the Properties of Polymeric Material : Oil and Ozone Reaction Time (고분자재료의 물성에 미치는 환경인자의 영향: 오일 및 오존반응시간)

  • 박찬영
    • Journal of Environmental Science International
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    • v.9 no.6
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    • pp.511-515
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    • 2000
  • The purpose of this experiment is to prepare ethylene propylene diene terpolymer(EPDM)/ acrylonitrile butadiene rubber(NBR) blend which represents good environmental resistant properties including favorable oil and ozone resistance. With incorporation of EPDM, NBR and other ingredients, the rubber and chemical additives were mixed by mechanical method such as Banbury mixer and open 2-roll mill. Then rubber vulcanizates were manufactured by hot press and mechanical properties, oil and ozone resistance of the test specimens were measured. The oil resistance and ozone resistance of EPDM and NBR, respectively, is remarkably improved by blending EPDM with NBR. The optimum results of oil and zone resistant characteristics were obtained at EPDM/NBR(=25/75 wt%) composition ratio.

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Effects of Ozone Oxidation on the Contact Resistance of DRAM Cell (오존 산화가 DRAM 셀의 콘택 저항에 미치는 영향)

  • 최재승;이승욱;신봉조;박근형;이재봉
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.2
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    • pp.121-126
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    • 2004
  • In this paper, the effects of the ozone oxidation of the landing polycrystalline silicon on the cell contact resistance of the DRAM device were studied. For this study, the ozone oxidation of the landing polycrystalline silicon layer was performed under various conditions, which was followed by the normal DRAM processes. Then, the cell contact resistance and $t_{WR}$ (write recovery time) of the devices were measured and analyzed. The experimental results showed that the cell contact resistance was more significantly increased for higher temperature of oxidation, longer time of oxidation, and higher concentration of ozone in the oxidation furnace. In addition, the TEM cross-sectional micrographs clearly showed that the oxide layer at the interface between the landing polycrystalline silicon layer and the plug polycrystalline silicon layer was increased by the ozone oxidation. Furthermore, the rate of the device failure due to too large write recovery time was also found to be well correlated with the increase of the cell contact resistance.

Effect of Environmental Factors including Ozone on the Properties of EPDM Rubber and CR Rubber Blend (오존을 포함한 환경인자가 EPDM고무와 CR고무 블렌드의 물성에 미치는 영향)

  • Min, Seong Gi;Lee, Won Gi;Park, Ye Jin;Hyeon, Jung Won;Park, Chan Yeong
    • Journal of Environmental Science International
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    • v.13 no.4
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    • pp.421-427
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    • 2004
  • With the help of mechanical mixing method such as Banbury mixer and open 2 roll mill, ethylene propylene diene terpolymer (EPDM) was blended with the chloroprene rubber (CR) then mechanical properties and ozone resistance test of blends were subsequently investigated. It was noted that the hardness increased with an increasing of CR contents. Generally the hardness was increased with heat aging time most likely due to the post cure. In ozone resistance test of blend, after 8 hours a portion of fine crack is obtained for pure CR. It is confirmed that ozone resistance is greatly improved by addition of 25wt% EPDM to CR.

Change of SOD, POD Activity and Stomata Resistance for Ozone on Rice(Oryza sativa L.) (오존 처리에 의한 벼 품종간 SOD, POD 활성과 기공저항성의 변화)

  • Chung, Ill-Min;Kim, Kwang-Ho;Kang, Byeung-Hoa
    • Korean Journal of Environmental Agriculture
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    • v.19 no.2
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    • pp.160-165
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    • 2000
  • This study was carried to select the tolerance in rice varieites for ozone treatment through comparing SOD, POD and stomata resistance. In SOD Acivity, Sangnambatbyeo showed the highest activity on 1 hr after ozone treatment and after 24 hr, SOD activity was decreased. SOD activity of Hangangchalbyeo was not different in observed all times after ozone treatment. In POD activity, Hangangchalbyeo, Sangnambatbyeo and Ilpumbyeo were similar to POD activity but Baeknabyeo was the lowest activity on 1 hr after ozone treatment. Also, all varieties represnted the highest activity (above 90 %) an 24 hr after ozone treatment. In stomata resistance, Sangnambatbyeo was decreased stomata resistance on 1 hr after ozone treatment. Hangangchalbyeo, Sangnambatbyeo and Baekna were decreased stomata resistiance on 24 hr after ozone treatment except Ilpumbyeo.

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Preparation and Characterization of Hybrid Ozone Resistance Coating Film Using Carbon Nanotube (탄소나노튜브를 이용한 하이브리드 내오존성 코팅 막의 제조 및 특성)

  • Kim, Sung Rae;Lee, Sang Goo;Yang, Jeong Min;Lee, Jong Dae
    • Polymer(Korea)
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    • v.38 no.5
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    • pp.573-579
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    • 2014
  • The effect of synthesis conditions such as carbon nanotube (CNT), 2,2,2-trifluoroethylmethacrylate (3FMA), and composition of organic-inorganic material in ozone resistance and surface characteristics of ultraviolet cured organic-inorganic hybrid coating film has been investigated. Coating solution was prepared using tetraethoxysilane (TEOS), silane coupling agent methacryloyloxypropyltrimethoxysilane (MPTMS), 3FMA, various organic materials with acrylate group, and CNT, then bar-coated on substrates using applicator, and densified by UV-curing. It was found that ozone resistance and adhesion of the coating film were strongly dependent upon contents of TEOS, 3FMA, and CNT. Especially, ozone resistance, adhesion, and surface hardness of coating film with CNT were improved, relatively. Ozone resistance of coating film with a high TEOS content was increased, but adhesion was decreased. In addition, it was also found that ozone resistance of coating film was increased with contents of 3FMA. On the other hand, surface hardness was decreased with increase of 3FMA.

Varietal Difference of Resistance to Ozone Injury in Rice Plant (벼 품종별 오존 피해 저항성 차이)

  • 손재근;이상철
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.3
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    • pp.338-343
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    • 1997
  • The response of seventy-five rice cultivars to ozone (O$_3$) were tested in the open-top chamber with ozone producing and monitoring system to determine the varietal difference of resistance to $O_3$ stress. Ozone was produced by electrostatic discharge in oxygen and was monitored by UV absorption ozone analyzer. Difference in response of rice to ozone was more clearly appeared on rice plants treated for 2 to 4 hours at 0.3 ppm concentration of $O_3$. Varietal resistance of rice to ozone was more distinctly classified at 21- to 35-day seedlings compared with 14-day rice plants. Most of indica and Tongil(indica$\times$japonica) type rice cultivars were more resistant than that of japonica cultivars based on the leaf injury to $O_3$. Eight Korean cultivars belong to japonica groups showed highly resistant reaction to $O_3$. Ozone exposure during booting stage caused lower grain fertility than exposures during seedling, maximum tillering and heading stages of rice.

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A study on the evaluation of field application for the waterproofing or corrosion proof construction method, as coating high quality filtration plant with ozone resistance paints of phenol degeneration polyamine (페놀 변성 폴리아민계 내오존도료를 이용한 고도정수처리장의 방수$\cdot$방식 공법에 대한 현장 적용성 평가에 관한 연구)

  • Jung Mun-Jung;Kwon Shi-Won;Oh Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2005.11a
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    • pp.33-38
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    • 2005
  • It is applied in the high quality equipment construction by introduction of this high duality treating technology (ozone treating, activated carbon treating, high quality oxidation treating, UV treating etc.)waterproofing or corrosion proof method caused secondary economy damage of operation discontinuance and high quality treating equipment for applying existent waterproofing method that corrosion proof ability (ozone resistance performance, chemical resistance etc.) and abrasion resistance performance by comprehension insufficiency of user and designer. Therefor, In this study, we will analyze problem of waterproofing and corrosion material of existing construction application by high quality treating, and measure physical performance change by various condition. It is required to waterproofing and corrosion system and application of the field valuation.

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Studies on the Ozone Resistance and Physical Properties of SBR/EPDM Blend Compound due to EPDM Content Variation (EPDM 함량 변화에 따른 SBR/EPDM 블렌드 혼합물의 내오존성과 물리적 성질에 관한 연구)

  • Ha, Ki-Ryong;Lee, Jong-Cheol;Kim, Tae-Geun;Hwang, Ki-Seob
    • Elastomers and Composites
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    • v.43 no.1
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    • pp.8-17
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    • 2008
  • Styrene-butadiene rubber(SBR) has good abrasion resistance, miscibility, and anti-vibration property. however, it is easily damaged by ozone and swelled by hydrocarbon fluids because of unsaturation part in main chain, that causes loss of visco-elasticity and reduction of product's life cycle. Therefore, object of this study is to cope with this problem. SBR is blended with various proportion of ethylene-propylene-diene terpolymer(EPDM), which has excellent ozone and oxygen resistance, to improve physical properties and ozone resistance, and diverse analytical techniques are used to measure morphology, glass transition temperature$(T_g)$, ozone-resistance, degradation temperature, static spring constant, hardness for considering a suitability for anti-vibration industrial product. We found that the blend consisting of SBR 70% and EPDM 30% showed no crack after ozone test and good miscibility between SBR and EPDM from this study.