• Title/Summary/Keyword: Protective Material

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High Luminous Efficacy and Low Driving Voltage PDP with SrO-MgO Double Protective Layer

  • Whang, Ki-Woong;Jung, Hae-Yoon;Lee, Tae-Ho;Cheong, Hee-Woon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.173-176
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    • 2009
  • We suggest a new protective layer for PDP consists of SrO and MgO double layer. This double layer structure protects SrO layer from the contamination by $H_2O$ or $CO_2$ in the air and enable SrO to play as the main cathode material. It was confirmed that the high secondary electron emission characteristics of SrO by Xe ion can bring considerable driving voltage reduction and improvement of luminance and luminous efficacy in PDP.

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Corrosion Inhibition Screening of 2-((6-aminopyridin-2-yl)imino)indolin-3-one: Weight Loss, Morphology, and DFT Investigations

  • Nadia Betti;Ahmed A. Al-Amiery
    • Corrosion Science and Technology
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    • v.22 no.1
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    • pp.10-20
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    • 2023
  • Because of its inexpensive cost, mild steel is frequently employed as a construction material in different industries. Unfortunately, because of its limited resistance to corrosion, a protective layer must be applied to keep it from decaying in acidic or basic environments. The presence of heteroatoms, such as nitrogen, oxygen, and pi-electrons in the Schiff base could cause effective adsorption on the mild steel surface, preventing corrosion. The weight loss method and scanning electron microscopy (SEM) were used to investigate the inhibitory effects of APIDO on mild steel in a 1 M hydrochloric acid environment. The efficiency of inhibition increased as the inhibitor concentration increased and decreased as the temperature increased. The SEM analysis confirmed that the corrosion inhibition of APIDO proceeded by the formation of an organic protective layer over the mild steel surface by the adsorption process. Simulations based on the density functional theory are used to associate inhibitory efficacy with basic molecular characteristics. The findings acquired were compatible with the experimental information provided in the research.

DENTINAL MICROLEAKAGE STUDY ON THE LIGHT CURABLE RESTORATIVE GLASS IONOMER CEMENT (광중합형 충전용 글라스 아이오노머 시멘트의 상아질 변연누출에 관한 정량분석)

  • Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.20 no.2
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    • pp.832-838
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    • 1995
  • The purpose of this study was to evaluate the amount of marginal microleakage of 2 light curable GI cements(Fuji II LC & VariGlass), which contain some resin components. 4 volunteers kept on acrylic resin plates, which contained dentin disks with cavities filled with test materials for 2 weeks. The time when polishing was done(5 minutes and 24 hours after filling) and the use of protective agents were varied, so 8 groups with each 6 specimens were tested. After having specimens(disks with cavities filled with materials) penetrated with 1% Methylene Blue solution, specimens were stored in 40% nitric acid solution for 4 days to extract adsorbed dye material. Supernatants of centrifuged samples were diluted 5 times and Spectrophotometer was used to determine the degree of absorption. Dye concentration was calculated through the pre-obtained Linear Regression Curve. The results were as follows. 1. The best result was seen in groups (PF24, PV24) which were protected and polished 24 hours later and the opposite phenomenon was seen in groups(NF24, NV24) which were held without protection and polished 24 hours later. Groups polished S minutes later showed moderate leakage pattern. 2. Groups polished 5 minutes later showed similar leakage amount irrespective of using of protective agent. But statistically insignificant lower values were seen in VariGlass than in Fuji II LC groups, So It was considered that VariGlass may be more resistant to early moisture attack than Fuji II LC. 3. In groups polished 24 hours later, there was no significant difference between materials but was definitely significant difference according to the use of protective agent. If the cement in which polishing will be done 24 hours later, Protective agent should be used to cover the surface.

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Visualization of Self-Healing Function of Protective Coating for Concrete (콘크리트 보호코팅재의 자기치유 기능의 시각화)

  • Kim, Dong-Min;Choi, Ju-Young;Jin, Seung-Won;Nam, Kyeong-Nam;Park, Hyeong-Joo;Chung, Chan-Moon
    • Journal of Convergence for Information Technology
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    • v.9 no.10
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    • pp.87-93
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    • 2019
  • Microcapsules were prepared by using a mixture of linseed oil and a small amount of fluorescent fluid as a core material. Self-healing protective coatings were prepared by applying coating formulations containing varying amounts of microcapsules on mortar surface. After scratch or crack was generated in the coating, when the damaged region was exposed to ultraviolet light (${\lambda}=365nm$), it was observed that fluorescence emission area increased with increasing microcapsule loading. In the cases of the self-healing coatings having 20wt% or more microcapsule loading, the damaged region was almost filled with the healing agent. In water sorptivity test, the self-healing coating having 20wt% or more microcapsule loading showed a healing efficiency of about 85%. The fluorescence emission from the damaged region was easily observed at a distance of 3 m. The self-healing protective coating is expected to be useful to confirm its self-healing function with the eye.

Anti-oxidative Effects of Taraxaci Herba and Protective Effects on Human HaCaT Keratinocyte (포공영 추출물의 항산화 효과 및 피부 각질세포 보호효과)

  • Kim, Hyung-Woo;Kim, Byung-Joo;Lim, Se-Hyun;Kim, Hyun-Yung;Lee, Sook-Young;Cho, Su-In;Kim, Young-Kyun
    • The Korea Journal of Herbology
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    • v.24 no.3
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    • pp.103-108
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    • 2009
  • Objectives : This study was carried out to investigate anti-oxidative effects of Taraxaci Herba (TH) and protective effects on Human HaCaT keratinocyte. Methods : Anti-oxidative effects were measured by estimating the amount of total phenolics and flavonoids. In addition, DPPH free radical scavenging activities were estimated. Protective effects of TH on HaCaT keratinocytes against oxidative stress induced by hydrogen peroxide were also measured. Results : In our results, treatment with TH did not show cytotoxicity on HaCaT keratinocyte beneath the concentration of 200 $\mu$g/ml. 42.64$\pm$1.90 $\mu$g/ml of total phenolics and 28.09$\pm$1.84 $\mu$g/ml of flavonoids was detected from TH ethanol extract. In addition, DPPH free radical scavenging activities of TH were elevated in dose-dependent manner. In addition, The value of half maximal inhibitory concentration (IC$_{50}$) was 165.5 $\mu$g/ml. Finally, TH showed protective effect against cell death of HaCaT cell induced by hydrogen peroxide significantly. Conclusions : In conclusion, these results suggest that TH may have anti-oxidantic action in human skin and also suggest the possibility as cosmetic material.

A Study on Impact Resistance Properties with Composition Materials and Installation Conditions of Protective Panel (방호 패널의 구성 재료 및 설치 조건에 따른 내충격 특성에 관한 연구)

  • Seok, Won-Kyun;Kim, Young-Sun;Lee, Yae-Chan;Nam, Jeong-Soo;Kim, Gyu-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.6
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    • pp.715-726
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    • 2023
  • This study suggested that protective panels should be installed as sacrificial members as a safety design method for structures with potential explosions such as hydrogen charging stations to minimize direct damage to the structure and have resilience. To this end, the focus of the experiment is on quantitatively evaluating the impact of the structure when the protection panel is installed closely or spaced apart from the structure in a high-speed collision situation of the projectile. The experimental design used steel plates instead of concrete structural members mainly used in the past for excellent reproducibility, and the impact of structural members was compared and analyzed through deformation differences on the back of the steel plate. In addition, the impact of changes in the physical properties of the elastic body used as a separation material for the protective member and the difference in shock wave transmission time according to the protective member and the elastic body on the structural member was investigated.

A Study on the Two-Step CMP for Prevention of Over-polishing (과다연마 방지를 위한 두 단계 CMP에 관한 연구)

  • Shin, Woon-Ki;Kim, Hyoung-Jae;Park, Boum-Young;Park, Ki-Hyun;Joo, Suk-Bae;Kim, Young-Jin;Jeong, Hae-Do
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.525-526
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    • 2007
  • Over-polishing is required to completely remove the material of top surface across whole wafer, in spite of a local dishing problem. This paper introduces the two-step CMP process using protective layer and high selectivity slurry, to reduce dishing amount and variation. The 30nm thick protective oxide layer was deposited on the pattern, and then polished with low selectivity slurry to partially remove the projected area while suppressing the removal rate of the recessed area. After the first step CMP process, high selectivity slurry was used to minimize the dishing amount and variation in pattern structure. Experimental result shows that two-step CMP process can be successfully applicable to reduce the dishing defect generated in over-polishing.

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Effect of Long-term Corona-discharge on RTV Silicone Rubber (장기 코로나 처리에 따른 RTV 실리콘 절연재료의 특성변화)

  • Youn, Bok-Hee;Ahn, Jong-Sik;Huh, Chang-Su
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.266-269
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    • 2001
  • This paper investigated the aging characteristic under long-term corona discharge on roan temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge. the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains $(CH_3)$ and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

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Effect of Long-term Corona-discharge on RTV Silicone Rubber (장기 코로나 처리에 따른 RTV 실리콘 절연재료의 특성변화)

  • 연복희;안종식;허창수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.266-269
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    • 2001
  • This paper investigated the aging characteristic under long-term corona discharge on loon temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge, the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains (CH$_3$) and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

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The Protective Effect of Zizania latifolia Extract against t-BHP-induced Oxidative Stress in HepG2 Cells (고장초 추출물의 t-BHP로 산화적 손상이 유도된 HepG2 세포 보호 효과)

  • Park, Se-Ho;Lee, Jae-Yeul;Yang, Seun-Ah;Bang, Daesuk;Jhee, Kwang-Hwan
    • Journal of Life Science
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    • v.31 no.3
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    • pp.338-345
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    • 2021
  • Zizania latifolia has long been used as a tea for both edible and medicinal purposes. However, research into the use of Z. latifolia as a high value-added edible material is lacking. In a previous study, we confirmed that tricin is the major component in Z. latifolia. In this study, we investigated the protective effect of a Z. latifolia extract (ZLE). Toxicity tests of ZLE or tricin on HepG2 cells revealed no toxicity due to ZLE or tricin at all concentrations used. The reduction in cell viability by tert-butyl hydroperoxide (t-BHP) was suppressed by treatment with ZLE or tricin. In addition, ZLE or tricin effectively inhibited the production of reactive oxygen species (generation of hydrogen peroxide, alkoxy free radicals, and peroxyl free radicals by t-BHP) and oxidative damage. ZLE or tricin treatments also increased the protein expression of superoxide dismutase 1 (SOD1), catalase, heme oxygenase-1 (HO-1), and nuclear factor erythroid-related factor 2 (Nrf2), which are known as antioxidant enzymes, suggesting that the protective effect of ZLE is related to activation of tricin. Taken together, the results indicate that Z. latifolia can be developed as a functional food material for improving liver function.