• 제목/요약/키워드: UV resistance

검색결과 415건 처리시간 0.025초

The Coating Performance of UV Curable Urethane Acrylate Coatings for Fancy Veneer Overlayed Plywood Flooring

  • Lee, Byoung-Hoo;Kim, Hyun-Joong;Lee, Young-Kyu
    • Journal of the Korean Wood Science and Technology
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    • 제32권6호
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    • pp.23-35
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    • 2004
  • The goal of study was to investigate the influence of the acrylated urethane oligomer on mechanical properties, the chemical resistance and thermal resistance of the UV curable urethane acrylate coatings for fancy veneer overlayed plywood flooring. The pencil hardness and abrasion resistance of the coated fancy veneer overlayed plywood floorings increased with increasing the acrylate functionality of the acrylated urethane oligomer. In the case of the UV cured film containing hexa-functional acrylated aliphatic urethane oligomer, high discoloration of the coated fancy veneer overlayed plywood flooring was observed near the cracks at the beginning of the chemical treatment. In this study, it was found that the degradation of the UV cured film caused by an alkaline reagent was higher than that of the UV cured film caused by an acidic treatment.

EFFECTS OF UV-B RADIATION ON GROWTH AND DEVELOPMENT OF RICE CULTIVARS (ORYZA SATIVA L.).

  • T.Kumagai;Kang, H.S.;J.Hidema;T.Sato
    • 한국식물학회:학술대회논문집
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    • 한국식물학회 1994년도 94 Symposium on Plant science September 10, 1994 Ewha Womans University, Seoul, Korea 94 식물학 심포지움 환경 스트레스와 식물의 반응
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    • pp.29-39
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    • 1994
  • Serious issues about the changes in the environmental conditions on earth associated with human activities have arisen, and the interest in these problems has increased. It is urgent to determine how the expansion of terrestrial UV-B radiation due to the stratospheric ozone depletion influences living matters. In this connection, we have been investigating the effects of UV-B radiation on the growth of rice cultivars (Oryza sativa L.). We report here some physiological and genetic aspects of resistance to inhibitory effects of UV-B radiation on growth of rice cultivars as described below. Elevated UV radiation containing large amount of UV-B and a small amount of UV-C inhibited the development of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Similar results were obtained in experiments, in which elevated UV-V radiation. Similar results were obtained in experiments, in which elevated UV-B radiation (transmission down to 290 nm) was applied instead of UV-B radiation containing a small amount of UV-C. The inhibitory effects of UV radiation was alleviated by the elevated CO2 atmospheric environment or by the exposure to the high irradiance visible radiation. The latter suggested the possibility that the resistance to the effects of UV radiation was either due to a lower sensitivity to UV radiation or to a greater ability to recover from the injury caused by UV radiation through the exposure to visible radiation. The examination of cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes (aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups showed the following: Various cultivars having different sensitivities to the effects of UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to UV rakiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultuvars are cultivated. Form the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F2 plants generated by reciprocally crossing Sasanishiki and Norin 1 and F3 lines generated by self-fertilizing F2 plants, it was evident that the resistance to the inhibitory of elebated UV radiation in these rice plants was controlled by recessive polygenes.

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EFFECTS OF UV-B RADIATION ON GROWTH AND DEVELOPMENT OF RICE CULTIVARS (ORYZA SATIVA L.).

  • Kumagai, T.
    • Journal of Photoscience
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    • 제1권2호
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    • pp.135-141
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    • 1994
  • Elevated near-UV radiation, containing a large amount of UV-B and a small amount of UV-C, inhibited the development of leaves and tillers, the increase in biomass production, the elongation of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Elevated UV-B radiation filtered through cellulose diacetate film or UV-31 cut filter (transmission down to 290 nm) similarly suppressed each growth component above. Near-UV radiation-caused injuries were alleviated either by elevated CO$_2$ atmosphere or by exposure to high irradiance-visible radiation. On the basis of these findings, we examined cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes ( aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups. It was shown that .various cultivars having different sensitivities to the effects of near-UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to near-UV radiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of near-UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultivars are cultivated. From the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F$_2$ plants generated by reciprocally crossing Sasanishiki and Norin 1 and F$_3$ lines generated by self-fertilizing F$_2$ plants, it was evident that the resistance to the inhibitory effects of elevated near-UV radiation in these rice plants was controlled by recessive polygenes.

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유-무기 하이브리드 재료와 자외선 흡수제의 배합에 의한 자외선 차단 코팅 (UV Blocking Coatings by Combination of Organic-inorganic Hybrid Materials and UV absorbers)

  • 유동식;이지호;하진욱
    • 한국산학기술학회논문지
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    • 제7권6호
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    • pp.1296-1301
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    • 2006
  • 눈은 자외선과 가시광선에 노출되어 있다. 눈은 자외선 노출에 해로우므로 모든 자외선으로부터 눈을 보호해야 한다. 본 연구에서는 자외선 차단을 위해 투명 플라스틱에 유-무기 하이브리드 재료와 자외선 흡수제의 배합에 의한 자외선 차단 코팅하였고, PMMA, CR 39 및 PC기재에 적용하여 자외선 차단 효과를 조사하였다. 자외선 흡수제의 양이 증가할수록 자외선의 투과도는 낮았다. PMMA의 경우 자외선 투과도를 현저히 감소시켰으며 CR 39에서도 자외선 차단 효과가 있는 것으로 나타났다. 한편, PC자체에서는 자외선 차단효과가 있는 것으로 평가되었다. CR 39 렌즈의 부착력, 내약품성, 내온수성은 우수하였고, 연필 경도의 경우 4H였으며 내마모성은 좋지 않았다.

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아마직물의 방추성과 복합기능성 향상을 위한 연구 (Improvement of Wrinkle Recovery and Functional Properties in Linen Fabrics)

  • 강미정;권영아
    • 한국의류학회지
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    • 제34권11호
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    • pp.1859-1869
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    • 2010
  • This study provides improved wrinkle recovery and UV protection capabilities as well as an antibacterial and deodorizing function to linen fabrics for summer shirts. The results obtained from this study are as follows. By setting catalyst concentration to 1.2% and DMDHEU concentration to 6% respectively and applying a heat treatment to them at $160^{\circ}C$ for 5 minutes, the decrease of fabric strength could be minimized and the crease resistance of linen fabrics improved. Compared to the treatment with DMDHEU only, the crease resistance of linen fabrics could be maintained and degradation of their properties could be more effectively prevented by applying the mixture of the UV absorber and the nano silver to the DMDHEU resin. The UV protection of fabrics could be improved by adding the UV absorber. Although the separate treatment of resin or the nano silver had no effect on the improvement of the UV protection properties for treated fabrics, they could increase the UV protection capability when they were combined with the UV absorber. Linen fabrics could possess an antibiosis and deodorizing capability by applying the mixture of the UV absorber, the nano silver, and the resin. The UV protection, crease resistance and flexibility of finished fabrics were maintained even after laundering. Washed treated fabrics maintained excellent antibiosis and odor free capabilities compared to untreated fabrics.

옥외용 고분자 절연재료의 자외선 열화특성 연구 (A Study on the Ultraviolet Aging Characteristics of Outdoor Polymeric Insulating Materials)

  • 김영성;정순옥
    • 한국재료학회지
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    • 제9권4호
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    • pp.409-413
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    • 1999
  • Recently, the polymeric insulators have been accepted in several countries for the outdoor high voltage applications. In comparison with the conventional porcelain, polymeric insulators offer various advantages such as light weight, superior vandal resistance and better contamination performance. The outdoor polymeric insulating materials such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged under the various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-under the various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-ray on the surface of silicone rubber were investigated by using the weather-Ometer. The accelerated aging stresses were simulated by UV radiation, high temperature and humidity as well as water spray. These aging characteristics were examined through contact angle measurements, tracking resistance test, FT-IR and SEM/EDS analysis. The experimental results showed that tracking resistance decreases with increase in the UV-ray irradiation period. But the surface of silicone rubber kept hydrophobicity. It is found that the inorganic filler such as)$ Al(OH_3$ improves tracking resistance and the $Tio_2$is very effective in preventing degradation of silicone rubber surface from UV-ray.

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한강물로부터 분리된 방사선 내성 세균들의 계통학적 다양성 및 UV 내성 분석 (Phylogenetic diversity and UV resistance analysis of radiation-resistant bacteria isolated from the water in Han River)

  • 이재진;주은선;이도희;정희영;김명겸
    • 미생물학회지
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    • 제52권1호
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    • pp.65-73
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    • 2016
  • 이 논문은 서울 한강물에서 분리한 방사선 내성 세균군집과 분리된 신종 세균의 UV 내성 특성에 관한 내용이다. 세균은 R2A agar와 1/10 R2A agar를 사용하여 3 kGy가 조사된 한강물에서 분리되었다. 그 결과 방사선에 내성을 가지는 것으로 추측되는 균주를 60주 분리하였고, 본 연구 분석 자료로 사용하였다. 16S rRNA 유전자 염기서열 분석을 통해 분리균주 60개의 계통수를 파악한 결과, 3개의 문(4개의 속)이 확인되었고, Deinococcus-Thermus (Deinococcus)가 61.7%, Firmicutes(Exiguobacterium)는 15%, Bacteroidetes (Hymenobacter, Spirosoma)는 23.4%의 비중을 나타냈다. 분리균주 중 29개 균주가 Deinococcus, Hymenobacter, Spirosoma에 속하는 신종 또는 다른 신속으로 분류될 가능성을 보였으며, 앞으로 추가적인 신종 실험이 진행될 예정이다. 그리고 신종 예상균주를 9개 선정하여 UV 내성 실험을 진행한 결과, 9개 균주 모두 D. radiodurans $R1^T$ 균주 만큼 높은 UV 내성을 가지는 것으로 나타났다. 또한 분리된 Firmicutes (Exiguobacterium) 균주는 아직까지 방사선 내성 연구 보고가 되어 있지 않아서 추가적인 방사선 내성 연구가 필요하다.

Thermal Assisted UV-Ozone Treatment to Improve Reliability of Ag Nanoparticle Thin Films

  • Lee, Inhwa;Kim, Taek-Soo
    • 마이크로전자및패키징학회지
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    • 제21권1호
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    • pp.41-44
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    • 2014
  • We employed UV-Ozone treatment method for the fabrication of dense and highly conductive nanoparticle thin films. We demonstrated the UV-Ozone treatment effect on the silver nanoparticle thin films as a function of time and temperature. The capping layers of nanoparticles were decomposed after UV-Ozone treatment and dense nanoparticle thin films were obtained. Moreover, electrical and mechanical properties of the thin films after UV-Ozone treatment were measured by using resistance measurements under tension in an in-situ tensile tester. The initial resistance of nanoparticle thin films was decreased by 82.6% with optimized UV-Ozone treatment condition of $150^{\circ}C$ for 20 minutes.

DNA Repair Activity of Human rpS3 is Operative to Genotoxic Damage in Bacteria

  • JANG CHANG-YOUNG;LEE JAE YUNG;KIM JOON
    • Journal of Microbiology and Biotechnology
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    • 제15권3호
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    • pp.484-490
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    • 2005
  • Human ribosomal protein S3 (rpS3), which has a DNA repair endonuclease activity, is a multifunctional protein. This protein is involved in DNA repair, translation, and apoptosis. In particular, rpS3 has a lyase activity, which cleaves the phosphodiester bond of damaged sites such as cyclobutane pyrimidine dimers and AP sites. Here, using deletion analysis, we identified that the repair endonuclease domain resides in the C-terminal region (165-243 aa) of rpS3. We also found that ectopic expression of GST-rpS3 in bacterial strain BL21 promoted the resistance of these cells to ultraviolet (UV) radiation and hydrogen peroxide ($H_{2}O_{2}$) treatment. The repair domain of rpS3 was sufficient to exhibit the resistance to UV irradiation and recover cell growth and viability, showing that the repair activity of rpS3 is responsible for the resistance to UV irradiation. Our study suggests that rpS3 is able to process DNA damage in bacteria via its repair domain, showing the resistance to genotoxic stress. This implies that rpS3-like activity could be operative in bacteria.

옥외용 고분자 절연재료의 자외선 열화특성 연구 (A Study on the Ultraviolet Aging characteristics of Outdoor Polymeric Insulating Materials)

  • 김영성;이상진;박완기;정순욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1404-1406
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    • 1998
  • The outdoor polymeric insulating materials such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged by various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-ray on surface of silicone rubber were investigated by using the weather-Ometer. The accelerated aging stresses were simulated by UV radiation. high temperature and humidity as well as water spray. These the aging characteristics were examined through contact angle measurements, tracking resistance test, FT-IR and SEM/EDS analysis. the experimental results showed that tracking resistance decreases with increase in the UV-ray irradiation period. But the surface of silicone rubber kept hydrophobicity. It is found that the inorganic filler such as $Al(OH)_3$ improves tracking resistance and the $TiO_2$ is very effective in preventing degradation of silicone rubber surface from UV-ray.

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