• Title/Summary/Keyword: anti-abrasion

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Development of Composite Fly Ash Pipe (비회 운송용 유리섬유 복합관 개발)

  • Jeong, Gyu-Sang;Won, Sam-Yong;Moon, Jin-Sung
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.33-36
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    • 2007
  • The majority of fly ash pipes in thermal power stations use steel pipes. This makes frequent replacement inevitable due to severe abrasion near the hot and curved section of pipes. Recently, there have been efforts to prevent this abrasion with lining techniques using ceramic or basalt on the inner wall of the pipe. This study uses composite and anti-wear material to maximize the anti-abrasion effects on the hot section of the pipe. The thickness of the abrasion layer was determined by the abrasion ratio of material found through the experiment; the thickness of the reinforcement layer was determined by micromechanics. Experiments were conducted on epoxy resins to test for heat and abrasion. Anti-abrasion test using particle impingement was intended to recreate realistic conditions when abrasion occurs within the hot section of an actual pipe. This study analyzes the abrasion ratio obtained from both the specimen experiment and from on-site measurement and provides evidence that a combination of composites and anti-wear agent can be used to create a fly ash pipe that is lower in costs and higher in quality than what is used currently.

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Anti-Reflective Coating with Hydrophilic/Abraion-Resistant Properties using TiO2/SiOxCy Double-Layer Thin Film (TiO2/SiOxCy 이중 박막을 이용한 투명 친수성/내마모성 반사방지 코팅)

  • Lee, Sung-jun;Lee, Min-kyo;Park, Young-chun
    • Journal of the Korean institute of surface engineering
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    • v.50 no.5
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    • pp.345-351
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    • 2017
  • A double-layered anti-reflective coating with hydrophilic/abrasion-resistant properties was studied using anatase titanium dioxide($TiO_2$) and silicon oxycarbide($SiO_xC_y$) thin film. $TiO_2$ and $SiO_xC_y$ thin films were sequentially deposited on a glass substrate by DC sputtering and PECVD, respectively. The optical properties were measured by UV-Vis-NIR spectrophotometer. The abrasion-resistance and the hydrophilicity were observed by a taber abrasion tester and a contact angle analyzer, respectively. The $TiO_2/SiO_xC_y$ double-layer thin film had an average transmittance of 91.3%, which was improved by 10% in the visible light region (400 to 800 nm) than that of the $TiO_2$ single-layer thin film. The contact angle of $TiO_2/SiO_xC_y$ film was $6.9^{\circ}$ right after UV exposure. After 9 days from the exposure, the contact angle was $10.2^{\circ}$, which was $33^{\circ}$ lower than that of the $TiO_2$ single-layer film. By the abrasion test, $SiO_xC_y$ film showed a superior abrasion-resistance to the $TiO_2$ film. Consequently, the $TiO_2/SiO_xC_y$ double-layer film has achieved superior anti-reflection, hydrophilicity, and abrasion resistance over the $TiO_2$ or $SiO_xC_y$ single-layer film.

Improved Corrosion and Abrasion Resistance of Organic-Inorganic Composite Coated Electro-galvanized Steels for Digital TV Panels

  • Jo, Du-Hwan;Noh, Sang-Geol;Park, Jong-Tae;Kang, Choon-Ho
    • Corrosion Science and Technology
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    • v.14 no.5
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    • pp.213-217
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    • 2015
  • Recently, household electronic industries require environmentally-friendly and highly functional steels in order to enhance the quality of human life. Customers especially require both excellent corrosion and abrasion resistant anti-fingerprint steels for digital TV panels. Thus POSCO has developed new functional electro-galvanized steels, which have double coated layers with organic-inorganic composites on the zinc surface of the steel for usage as the bottom chassis panel of TVs. The inorganic solution for the bottom layer consists of inorganic phosphate, magnesium, and zirconium compounds with a small amount of epoxy binder, and affords both improved adhesion properties by chemical conversion reactions and corrosion resistance due to a self-healing effect. The composite solution for the top layer was prepared by fine dispersion of organic-inorganic ingredients that consist of a urethane modified polyacrylate polymer, hardener, silica sol and a titanium complex inhibitor in aqueous media. Both composite solutions were coated on the steel surface by using a roll coater and then cured through an induction furnace in the electro-galvanizing line. New anti-fingerprint steel was evaluated for quality performance through such procedures as the salt spray test for corrosion resistance, tribological test for abrasion resistance, and conductivity test for surface electric conductance regarding to both types of polymer resin and coating weight of composite solution. New composite coated anti-fingerprint steels afford both better corrosion resistance and abrasion properties compared to conventional anti-fingerprint steel that mainly consists of acrylate polymers. Detailed discussions of both composite solutions and experimental results suggest that urethane modifications of acrylate polymers of composite solutions play a key role in enhanced quality performances.

Design of Anti-abrasive curved ducts for high-velocity gas-solid flow (내마모성을 갖는 고속 분립체 이송용 곡관의 형상 설계)

  • 권동구;김윤제
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2000.04a
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    • pp.229-235
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    • 2000
  • A study on the improvement of anti-abrasion nature of curved ducts for high-velocity gas-solid flow which are typically equipped in a coal-burned steam power plant has been investigated numerically and experimentally. To reduced the abrasion of pipe by particle, we have tried to form the vortex flow field in the region where flow changes its direction , modelled with two different shapes. 22.5$^{\circ}$and 90$^{\circ}$ elbows. the governing equations for three -dimensional , turbulent flow fields are discretized by FVM and solved bySIMPLE algorithm . From the numerical analysis, the new designed elbows for reducing abrasion have been developed. Numerical results are compared with the experimental abrasion data which are obtained from one of the operating coal burned steam power plants in Korea. Comparison of these results show that the developed elbows have much more durability than the original one.

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Wet Environmental and Mechanical Characteristics for Polyethylene-based Insulating Materials (Polyethylene 계열 절연재료의 환경적·기계적 특성)

  • Song, Woo-Chang;Choi, Won-Seok;Park, Ha-Yong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.2
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    • pp.119-123
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    • 2014
  • In this study, four kinds of specimens of PE(polyethylene)-based insulating materials were prepared for selecting the optimum insulation materials in a wet environment. The specimens were tested by various methods, the anti tracking test, the transmittance test in the water vapor transmittance(WVT) and the abrasion resistive test, etc. The HDPE(high-density polyethylene) specimen was showed excellent property in the tracking resistance test and the lowest transmittance in water vapor transmittance test. In the abrasion resistive test, the LLDPE(linear low-density polyethylene) and MDPE(medium-density Polyethylene) were showed excellent mechanical properties. The value of cut-through resistance for MDPE and HDPE were superior to that for LLDPE and LDPE(low-density polyethylene).

Local Cervical Immunity in Women with Low-grade Squamous Intraepithelial Lesions and Immune Responses After Abrasion

  • Ekalaksananan, Tipaya;Malat, Praphatson;Pientong, Chamsai;Kongyingyoes, Bunkerd;Chumworathayi, Bandit;Kleebkaow, Pilaiwan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.10
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    • pp.4197-4201
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    • 2014
  • Minor trauma to the uterine cervix is supposed to induce local immunity to prevent cervical lesions caused by human papillomavirus (HPV) infection. This study aimed to investigate the local cervical immunity in women with low grade squamous intraepithelial lesion (LSIL) and effects of abrasion after cryosurgery or Pap smear. One hundred women with LSIL and known results of HPV detection were recruited. HPV positive women were randomly divided according to abrasion into cryotherapy and Pap smear observation groups. Cervical tissues and cervico-vaginal lavage (CVL) were collected at 6 and 12 months after allocation. The levels of cytokines at first recruitment were compared with cytokine levels at 6 months after abrasions. The mRNA of IFN-${\gamma}$, TNF-${\alpha}$ and IL-10 in cervical tissues and these cytokines secreted in CVL were determined using real time PCR and ELISA, respectively. Anti-HPV16 IgG and IgA antibodies in CVL were assessed by western blotting. At first recruitment of women with LSIL (100 cases), IL-10 mRNA and cytokine in HPV positive group (60 cases) was significantly higher than negative group (40 cases). IFN-${\gamma}$ and TNF-${\alpha}$ mRNA level in both groups were comparable but their secretions in CVL were significantly increased in HPV negative group. After abrasion for 6 months in HPV-positive women, all mRNA and secreted cytokines were changed, but no significant difference was observed between cryotherapy and observation groups. When individuals were compared between first recruitment and after abrasion for 6 months, IFN-${\gamma}$ mRNA and anti-HPV16 L1 IgA antibodies were significantly increased in the cryotherapy group. The results suggest that modulation of local cervical immunities by abrasion might promote different effects in clearance of HPV-related cytological abnormalities.

A Study on Coating Performance Design for Ice Belt Zone of the Arctic Vessels (극지 운항 선박 Ice Belt Zone의 도장 사양 설계 연구)

  • Baek, Yun-Ho;Park, Chung-Seo;So, Yong-Shin
    • Special Issue of the Society of Naval Architects of Korea
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    • 2013.12a
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    • pp.66-72
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    • 2013
  • The demand for an ice class ship is rising expected to rise according to the increase of energy consumption and the opening of arctic sea routes. Ice class ship should be designed to cope with the severe environmental conditions of arctic sea such as a high mechanical impact and abrasion damage, caused by pack ice, ice bergs and low temperature. The ice class ship hulls are coated with an anti-abrasion and low friction coating such as a solvent free epoxy or high solid-volume epoxy. These coatings require two-component heating pump and a high grade surface preparation. In this study, the coating performances for the arctic vessels, such as puncture absorbed energy, abrasive wear loss, friction coefficients and impact absorbed energy were evaluated. Based on this study, a proper coating performance specification for the arctic vessels was proposed and coating selection guideline in terms of coating performance and workability was also established.

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A Study on Wear Characteristics of High strength aluminum alloys by Surface Hardening (표면경화에 의한 고강도 알루미늄 합금의 마모 특성에 관한 연구)

  • Lee, Nam-Soo;Huh, Sun-Chul;Lee, Kwang-Young;Park, Won-Jo
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1601-1606
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    • 2007
  • In order for high strength aluminum alloys to be used in transportation systems and the aerospace industry, excellent mechanical and physical properties are required. In particular, excellent anti-abrasion property is indispensable for parts that require driving force. In general, surface treatment technologies such as high frequency heat treatment, gas solid carburizing, surface rolling, shot peening are used as ways of improving anti-abrasion property. Among various surface treatment technologies, this research chose shot peening processing for Al7075-T6, which is well known as representative high-strength alloy steel. Wear characteristics were compared and analyzed after shot peening processing with shot ball velocities of 40m/s and 70m/s in order to investigate the effects of shot peening processing on wear characteristics.

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A study on the improvement for performance of floor finishing materials using poly urethane with water reacting urethane (수반응 우레탄과 바닥용 경질 폴리우레탄을 이용한 바닥마감재의 성능향상에 관한 실험적 연구)

  • Kang, Hyo-Jin;Park, Jin-Sang;Park, Jong-Ook;Oh, Sang-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.653-656
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    • 2006
  • It is necessary for the new material and construction concept to make up for weak point which related to high durability and finish ability to solve exposure limit of exist construction method. This paper is deal with performance test(tier load, anti abrasion, anti impact, permeability, bond test) compositive using for water reacting soft urethane and rigid urethane to improve the exist problem which are crack movement, adhesive on the wet surface, impact and abrasion by tier load. It is getting decreasing demage compare with other exist materials after test by transfer load, movement and impact.

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Durability Enhancement of Textile Materials for Thermotherapy Massager (온열안마기용 섬유재료의 내구성 향상)

  • Lee, Joo-Young;Kim, Ho-Dong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.6
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    • pp.2292-2299
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    • 2010
  • The wear and abrasion mechanism of conventional PET/Cotton fabric which is used as a lining layer for thermotherapy massager was elaborately investigated in order to increase the life-span of the fabrics for Thermotherapy Massager. Based on the destruction mechanism, the feasible PET fabrics were prepared and its anti-wearing performance was evaluated. It is revealed that the wearing destruction is mainly caused by the repeat abrasion on a specific part of folded fabric as well as abrasion itself. Therefore, it is necessary that the prevention of fabric folding while massager is running is essential and the recovery from the crease on a fabric is also necessary to solve this problem. Covered elastic yarn, high twisted yarn, change of fabric structure or different fiber were utilized to prepare the possible alternatives. As a result, the anti-wearing performance of the fabrics are greatly improved to have about 2 times and 1.5 times longer life-span for the fabric with covered elastic yarn and high twisted yarn, respectively.