• Title/Summary/Keyword: 오존열화

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Early Detection of Foliar Damage Caused by Ozone Exposure with Thermal Image Analysis (식물체 잎표면의 열화상 분석을 통한 오존 피해 조기 진단)

  • 허재선;이충일
    • Korean Journal Plant Pathology
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    • v.12 no.1
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    • pp.132-136
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    • 1996
  • 오존에 의한 식물체의 가시피해 발현 이전에 나타나는 비가시적 피해를 찾아내기 위하여 적외선 열화상장치(infrared thermography)를 이용하여 하루 8시간씩 0.3 ppm 오존에 노출된 나팔꽃(Ipomoea purpurea)잎표면의 온도분포 변화를 조사하였다. 노출 첫날에는 온도분포의 뚜렷한 변화를 볼 수 없었다. 노출 2일째, 오존 노출 2시간 결과후, 완전히 자란 제3엽의 특정 부분에서 급격한 온도분포 변화를 보였으며, 그로부터 약 4시간 경과 후에 동일 지점에서 최초의 가시적 피해가 발생했다. 급격한 온도분포 변화를 보인 부분과 최초 가시피해가 발생한 부분이 일치한 점은 가시피해 발생과 그 이전의 온도분포 변화가 밀접하게 상관되어 있다는 것을 의미한다고 하겠다. 잎표면의 열화상 분석방법을 대기오염원에 의한 식물체의 가시피해 발현 이전에 진행되고 있는 비가시적 반응의 조기진단에 적용할 수 있으며 생태환경 친화적인 대기 환경관리를 위한 대기오염원은 배출조절용 생체반응기(biosensor)로 이용 가능하겠다.

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Techniques for Characterizing Surface Deterioration of Epoxy Exposed to Ozone Damage (오존에 노출된 에폭시 코팅재의 표면 열화특성 평가기술)

  • Choi, Sung-Min
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.3
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    • pp.167-177
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    • 2014
  • New technologies for water purification are continuously emerging to address global water quality problems, and one such technology involves advanced hermetic water purification facilities made by concrete that utilize ozone treatment processes. Better knowledge about surface deterioration of epoxy coating exposed to ozone treatment is needed as a foundation for development of improved methods and materials in the future. This study utilized atomic force microscopy (AFM), nanoindentation methods, and existing indirect methods such as visual observation, changes in mass, surface observation and chrominance analysis, to evaluate epoxy water-resistance and anti-corrosiveness. This study considered six different epoxy formulations to assess typical degradation characteristics of epoxy surfaces with regard to water-resistance/anti-corrosiveness. AFM and nanoindentation techniques emerged as promising direct methods with potential to provide quantitative measures of surface quality that are improvements upon existing indirect methods. The experiments also confirmed that some of the epoxy-coatings were severely iMPacted by ozone exposure, and thus the results demonstrate that concern about such deterioration is justified.

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.

고분자(高分子) 재료(材料)의 오존열화(劣化) 및 방지(防止) 메커니즘

  • Heo, Dong-Seop
    • Elastomers and Composites
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    • v.16 no.4
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    • pp.217-227
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    • 1981
  • 오존은 PE나 고무 등 고분자재료(高分子材料)의 표면(表面)에 존재하는 이중결합(二重結合)에 대(對)하여 친전자적부가반응(親電子的付加反應)으로 ozonide가 생성되고 이어서 제(第)3급(級) 수소(水素)를 공격하므로서 주쇄(主鎖)가 절단된다. 따라서 aldehyde, ketone 등의 carbonyl 화합물(化合物)이 생성된다. 이들이 재료표면(材料表面)의 굴곡변형(變形)의 증가에 따라 열(熱) 또는 공(光)에 의하여 다시 분해(分解)를 촉진시킨다. 2개(個)의 N분자(原子)에 방향족(芳香族) 및 지방족기(脂肪族基)를 각각 치환시킨 p - phenylene diamine 유도체(誘導體) 등과 같은 전자공흥성(電子供與性)이 큰 화합물(化合物)은 친전자적(親電子的)인 오존과 우선적으로 3급(級) 수소에 비하면 약 100 배(倍)로 반응성이 크다는것을 표(表)3으로 알수 있다. 미단이중결합(未端二重結合)에 대한 오존과의 반응은 다음 반응식과 같이 이중결합(二重結合)에 오존의 부가반응(付加反?)으로 개시(開始)되어 peroxi methylene이 유리되면서 미단(未端)은 aldehyde로 변화한다. 또 1개의 반응은 제(第)3급(級) 탄소-수소 결합에 오존이 삽입되고 계속 일어나는 분해반응으로서 hydroperoxide의 생성 및 탈염화수소(脫鹽化水素)반응이 일어난다. 이와같은 반응(反?)으로 생성(生成)된 내부(內部) 이중결합(二重結合)에 대한 오존의 반응은 olefin의 경우와 마찬가지로 molozonide나 ozonide의 과정을 거쳐 주쇄(主鎖)가 개열(開裂)되는 것이다.

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Evaluation of Ozone Resistance and Anti-Corrosion Performance of Water Treatment Concrete according to Types of Metal Spray Coating (수처리시설용 콘크리트의 금속용사 피막 종류에 따른 내오존성 및 전기화학적 방식 성능 평가)

  • Park, Jin-Ho;Choi, Hyun-Jun;Lee, Han-Seung;Kim, Sang-yeol;Jang, Hyun-O
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.4
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    • pp.61-68
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    • 2019
  • As the pollution of water resources deteriorates due to industrialization and urbanization, it is difficult to supply clean water through a water treatment method using chlorine. Therefore, the introduction of advanced water treatment facilities using ozone is on the increase. However, epoxy which is used as waterproofing and anticorrosives and stainless steel used in conventional waterproofing and anti-corrosive methods have deteriorated because of the strong oxidizing power of ozone, causing problems such as leaking. Moreover, it even causes the durability degradation of a concrete. Therefore, in this study, metal spraying system was used as the means of constructing a metal panel with excellent ozone resistance and chemical resistance which is an easier method than an existing construction method. Ozone resistance was evaluated in accordance with the type of metal sprayed coatings to develop a finishing method which can prevent the concrete structure of water treatment facilities from deterioration. Furthermore, electrochemical stability in actual sewage treatment plant environment was evaluated. Experimental results showed that Ti has superior ozone resistance after spraying and the electrochemical stability in the sewage treatment plant environment showed that Ti has the highest polarization resistance of $403.83k{\cdot}{\Omega}{\cdot}cm^2$, which ensures high levels of durability.

Characterization of $SnO_2$ Thin Films Prepared by Thermal-CVD (열화학증착법으로 제조된 $SnO_2$박막의 특성)

  • Ryu, Deuk-Bae;Lee, Su-Wan
    • Korean Journal of Materials Research
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    • v.11 no.1
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    • pp.15-19
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    • 2001
  • Transparent and conducting tin oxide thin films were prepared on soda lime silicate glass by thermal chemical vapour deposition. Thin films were fabricated from mixtures of tetramethyltin (TMT) as a precursor, oxygen or oxygen containing ozone as an oxidant. The properties of fabricated tin oxide films are highly changed with variations of substrate temperature. Optimized thin films could be prepared on TMT, which flow rate of 8 sccm, oxygen flow rate of 150 sccm and substrate temperature of 38$0^{\circ}C$. We reduced deposition temperature about$ 180^{\circ}C$ by using of oxygen containing ozone instead of pure oxygen and resistivity of thin films was decreased from ~ ${\times}10^{-2}{\Omega}cm$ to ~${\times}10^{-3}{\Omega}cm$.

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Influence of Thermal Aging on the Properties of Polyurethane Coating of Waterproof. (우레탄 도막 방수재의 열열화 특성)

  • Kim, Sung-Rae;Shin, Hong-Chol;Shin, Ju-Jae;Kim, Young-Geun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.931-934
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    • 2008
  • Polyurethane apply to the waterproof widely. Polyurethane rubbers are prepared that the influences of a thermal aging on the properties are investigated. Polyol and Polyisocyanate were varied ratio in the range mixed by using individual product that was vulcanized by a hot. The waterproofs of Polyurethane were investigated about tensile strength, tear strength and elongation after the thermal Aging for 168, 336, 504 hrs at 70$^{\circ}$C and 80$^{\circ}$C in the air oven. As the increase of the thermal aging time, tensile strength, tear strength and elongation were reduced.

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TRACKING AND DIELECTRIC CHARACTERISTICS OF OZONE AGED SILICONE RUBBER USED FOR OUTDOOR INSULATI0N (옥외용 실리콘 고무의 장기 오존열화에 따른 내트랙킹 특성 및 유전특성 변화)

  • Lee, C.Y.;Kim, Y.H.;Lee, S.J.;Park, W.K.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1541-1543
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    • 1996
  • This paper describes the results of characteristics on the tracking resistance, hydrophobicity and dielectric properties of silicone rubbers used for outdoor insulation with ozone ageing. The tracking and ozone ageing tests for this purpose ware made in according to IEC 587 and ASTM D 1149, respectively. Additionally, we investigated the surface structure of the silicone rubbers with FT-IR and SEM. From the test results, it is proven that the higher the degree of ozon ageing, the worse tracking characteristics.

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A Literature Study on the Ozone Degradation of Concrete Structures in Water Treatment Facilities (수처리 시설 콘크리트 구조물의 오존 열화에 관한 문헌적 연구)

  • Park, Jin-Ho;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.177-178
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    • 2015
  • Recently, Advanced water treatment facilities with Ozone are being introduced owing to domestic water pollution. However, waterproofing/corrosion prevention construction method of concrete structure for existing advanced water treatment makes waterproofing/corrosion prevention materials and concrete deteriorated because of strong oxidation of ozone. it causes increase of maintenance cost and water quality degradation. Therefore, in this study, it will figure out problems of waterproofing/corrosion prevention construction method being applied to through existing studies.

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