• 제목/요약/키워드: surface protection

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데이터베이스 보호를 위한 법적 대응 방안에 관한 연구 (A Study on the Legal Countermeasure for the Protection of Databases)

  • 안계성;조소연
    • 정보관리학회지
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    • 제16권2호
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    • pp.27-48
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    • 1999
  • 저작권법에 의한 데이터베이스 보호에 문제가 제기되자 세계 각국에서는 추가적인 데이터베이스 보호법 제정 여부를 놓고 열띤 논의를 벌이고 있다. 본 연구에서는 저작권법에 의한 데이터베이스 보호의 문제점 및 최근 선진 각국의 데이터베이스 보호 입법 동향을 살펴보고 이를 토대로 국내 데이터베이스 산업 활성화를 위한 법적인 보호 대응책을 제안하였다.

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Corrosion protection behavior of AZ31 magnesium alloy with cathodic electrophoretic coating pretreated by cerium based conversion coatings at various pH

  • Fazal, Basit Raza;Phuong, Nguyen Van;Moon, Sungmo
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2015년도 추계학술대회 논문집
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    • pp.268-268
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    • 2015
  • The corrosion protection behavior of AZ31 magnesium alloy (Mg alloy) with cathodic electrophoretic coating (E-coating) pretreated by cerium-based conversion coatings at various pH was investigated in this study. Cerium-based conversion coatings (CeCCs) were deposited on AZ31 Mg alloy by immersion treatment in the nitrate-based cerium salt solution. The morphology and composition of the CeCCs were analyzed using scanning electron microscopy and energy dispersive X-ray spectroscopy. The corrosion properties of the AZ31 Mg alloy pretreated with cerium coating and subsequently E-coated were studied during salt-spray testing. The surface morphologies of the E-coated Mg alloy were examined in detail after different testing times using digital photography. It was found that the protective properties of the E-coating on AZ31 Mg alloy generated are heavily dependent upon the CeCC factors such as treatment time, coating thickness and pH of the solution.

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표면복사특성이 단열성능에 미치는 영향 (Effects of surface radiation on the insulation for mechanical system)

  • 오동은;박종일;이민우;홍진관;강병하;김석현
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.1006-1011
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    • 2006
  • In this study, a rational procedures for estimation of insulation thickness for condensation control or personnel protection has been investigated. Both horizontal pipe and vertical wall configuration are included. Design parameters are pipe diameter or, height of the wall, thermal conductivity, emissivity, and operating temperatures. The results Indicated that the surface emissivity plays a very important role in the design of insulation for the purpose of surface temperature control, especially in natural convection situation. radiation heat transfer coefficients for some new insulation material surface, such as elastomers, estimated to be more than 90% of the total surface heat transfer coefficient. Adequate revision of specifications or standards has been also suggested.

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이차전지 원료 해쇄용 그라인딩 디스크 어셈블리 표면 특성 시험에 관한 연구 (A Study on the Surface Properties Test of the Grinding Disk Assembly for Crushing Materials in Secondary Cells)

  • 한상필;이동혁
    • Design & Manufacturing
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    • 제17권2호
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    • pp.33-41
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    • 2023
  • Metal raw materials and chemical additives, which are raw materials for secondary batteries, are pulverized by the high-speed rotation of the Grinding Disc of the Classifier Separator Mill (CSM). Grinding discs are required to withstand abrasion, corrosion, high-speed rotational force and impact. In order to analyze the stability of domestic and foreign grinding discs, quality tests including surface roughness, surface lubrication, surface state measurement, and surface 3D shape measurement were analyzed. When producing developed products, it shows that excellent products can be produced.

매설가스배관의 음극방식이 배관의 파괴인성에 미치는 영향 (The Effects of cathodic protection on fracture toughness of buried gas pipeline)

  • 김철만;김우식
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집A
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    • pp.573-578
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    • 2001
  • For the corrosion protect ion of the natural gas transmission pipelines, two methods are used, cathodic protection and coating technique. In the case of cathodic protection, defects are embrittled by occurring hydrogen at the crack tip or material surface. It is however very important to evaluate whether cracks in the embrittled area can grow or not, especially in weld metal. In this work, on the basis of elastic plastic fracture mechanics, we performed CTOD test ing with varying test conditions, such as the potential and current density. The CTOD of the base steel and weld metal showed a strong dependence of the test conditions. The CTOD decreased with increasing cathodic potential and current density. The morphology of the fracture surface showed quasi-cleavage. Hydrogen introduced fractures, caused by cathodic overprotection.

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Study on Hygrothermal Degradation and Corrosion Protection of Epoxy Coatings Cured by Different Amine Based Curing Agents

  • Shon, Min-Young;Kwon, Huck-Sang
    • Corrosion Science and Technology
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    • 제9권5호
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    • pp.201-208
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    • 2010
  • Epoxy coatings cured by different amine based curing agents have been prepared. Atomic force microscopy (AFM) has been used to monitor the surface topology changes of epoxy coatings before and after hygrothermal cyclic test. The glass transition temperature ($T_g$) and coefficient of thermal expansion (CTE) of the epoxy coating were measured by Thermo-mechanical Analysis (TMA). The Electrochemical impedance spectroscopy (EIS) with hygrothermal cyclic test has been introduced to evaluate the corrosion protection of the epoxy coatings. In conclusion, thermal properties of epoxy coatings were in good agreement with the results of corrosion protection of epoxy coated carbon steel obtained result by EIS with hygrothermal cyclic test. The relationship between thermal properties, surface roughness changes and corrosion protection of epoxy coatings are discussed in this study.

Airborne HPGe spectrometer for monitoring of air dose rates and surface activities

  • Marcel Ohera;Lubomir Gryc;Irena Cespirova;Jan Helebrant;Lukas Skala
    • Nuclear Engineering and Technology
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    • 제55권11호
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    • pp.4039-4047
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    • 2023
  • This contribution describes the application of HPGe detector for the airborne quantitative analysis. The hardware of the airborne HPGe system was designed from the commercial components with only exception of the newly designed AirHPGeSpec special software to control, measure and process the data. The system was calibrated for the local air kerma rates measured on helicopter board and its conversion to the air kerma rates at 1 m above the ground was proposed. Two examples of the air kerma rates measured over the former uranium mining areas are presented and compared with the results of other airborne system on the board. This airborne HPGe system could be also used for measuring the surface activities in a radiation event. The nuclides of 131I, 132Te - 132I, 133I, 134I, 135I, 137Cs, 134Cs, 88Rb and 103Ru were selected from possible nuclear power plant emergency scenarios. The Monte Carlo simulation was used to calculate HPGe detector efficiencies for the flight altitudes from 25 to 300 m for the energies from 300 keV to 3 MeV of the nuclides in question. Also, the detection limits according to the Currie method as well as ISO 11929-2010 for selected nuclides are presented.

무산소동의 표면부식 방지기술 적용에 관한 연구 (A Study on the Application of Anti-Corrosion Techniques on the Surface of Oxygen Free Copper)

  • 주형건;이대영;장다콴;이강용;아잠카미스
    • 대한기계학회논문집A
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    • 제33권4호
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    • pp.425-429
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    • 2009
  • The protection for copper tarnish was developed by surface treatment method and volatile corrosion inhibiting (VCI) technology. The performance of surface treatment and VCI material is also examined in simulated test environment. Benzotriazole (BTAH) solution that contained molybdate showed best performance than others. Usage of VCI materials with surface treatment was more effective. The protection film foamed on the surface of copper was investigated by auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). Molybdate does not participate in the formation of the protective film but promotes the passivation effect. This facilitates the stabilization of the cuprous oxide film, and strengthens the adsorption of BTAH.