• 제목/요약/키워드: material stability

검색결과 3,317건 처리시간 0.028초

Stability improvement for response attenuation of bridge columns with one dimensional meta-material based isolation systems

  • Saumitra Jain;Sumiran Pujari;Arghadeep Laskar
    • Earthquakes and Structures
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    • 제24권3호
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    • pp.193-204
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    • 2023
  • The concept of meta-material-based isolation systems (MMIS) for structural columns has been revisited in the present study in order to enhance the stability of rubber pads by using steel shim reinforced rubber (SSRR) layers. Analytical calculations have shown a significant improvement in the stability of MMIS with SSRR pads. Finite element analysis has also been conducted to further show the reduced response of a bridge with the modified MMIS under excitations having frequencies within the corresponding attenuation zone (AZ) as compared to the response of a conventional bridge without MMIS. FE analysis further shows the stress generated on the bridge with MMIS systems are within safe limits. Finally, a generalized procedure has been developed to design bridge columns with the proposed modified MMIS.

구리CMP공정시 알루미나 슬러리 안정성을 위한 Hydrogen peroxide의 적용 (Application of Hydrogen Peroxide for Alumina Slurry Stability in Cu CMP)

  • 이도원;김남훈;김인표;김상용;김태형;서용진;장의구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.136-139
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    • 2003
  • Copper has attractive properties as a multi-level interconnection material due to lower resistivity and higher electromigration resistance as compared with Alumina and its alloy with Copper(0.5%). Among a variety of agents in Copper CMP slurry, $H_2O_2$ has commonly been used as the oxidizer However. $H_2O_2$ is so unstable that it requires stabilization to use as oxidizer Hence, stabilization of $H_2O_2$ is a vital process to get better yield in practical CMP process. In this article the stability of Hydrogen Peroxide as oxidizer of Copper CMP slurry has been investigated. When alumina abrasive was used, $\gamma$-particle Alumina C had a better stability than $\alpha$-particle abrasive. As adding KOH as pH buffering agent, $H_2O_2$ stability in slurry decreased. Urea hydrogen peroxide was used as oxidizer, an enhanced stability was gotten. When $H_3PO_4$ as $H_2O_2$ stabilizer was added, the decrease of $H_2O_2$ concentration in slurry became slower. Even though adding $H_2O_2$ in slurry after bead milling lead to better stability than in advance of bead milling, it had a lower dispersibility.

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상전이물질을 함유한 폴리우레아 마이크로캡슐의 제조와 섬유복합소재에의 적용 (Preparation of Polyurea Microcapsules Containing Phase Change Material and their Application on Fiber Composites)

  • 김혜인;김현진;최해욱;박수민
    • 한국염색가공학회지
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    • 제19권1호
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    • pp.37-44
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    • 2007
  • In this study, for textile use, the octadecane of phase change materials(PCM) was encapsulated in several micro-diameter shell which prevents leakage of the material during its liquid phase. Microencapsulated PCM(PM) was prepared with the different weight ratio of core material to wall material and by interfacial polymerization methods using polyurea as shell material. Phase stability for O/W emulsion of PCM and PVA aq. (PE) was evaluated by Turbiscan Lab. The capsule formation win identified using FT-IR. Physical properties of microcapsules including diameter, particle distribution, morphology were investigated. Thermal transport properties of suede treated with PM(SPM) were determined by KES-F7 system.

무기질계 탄성 도막재와 고무 아스팔트를 적층한 일체형 방수재의 시공특성에 관한 실험적 연구 (A study on a performance the appliable rubber asphalt of monolithic waterproofing material of construction quality and the cement polymer modified waterproof coating membrane material of surface treatment.)

  • 박진상;최성민;박영태;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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    • pp.223-226
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    • 2005
  • In this study on the appliable Asphalt sheet of monolithic and inorganic matter waterproofing ,Fing material using of field because of problem of complex waterproofing sheet. Before this cement polymer modified waterproof coating and appliable asphalt sheet of monolithic whether have stability by method of construction about all style waterproofing that evaluate to new method of construction development naturally big emphasis put and try to approach. Did performance test item first at, as a result, drew by suitable thing in all KS items. This is considered to have more effective spot construction work because if means that have stability by material as well as method of construction.

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중금속 및 유류로 오염된 토질의 성토재료로서의 안정성에 관한 연구 (The Research on The Stability as Fill Material of Soil Defiled by Oil Element and Heavy Metals)

  • 이충숙;엄태규;최용규;이민희
    • 한국지반환경공학회 논문집
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    • 제5권2호
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    • pp.5-13
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    • 2004
  • 아파트 건설용 부지내에서 중금속 및 유류로 오염된 토사가 발견되었다. 7개 위치에서 대표적인 시료를 채취하였으며 이 오염된 토사의 지반공학적 안정성을 확인하기 위하여 중금속 및 유류에 대한 환경공학적 검토가 이루어졌다. 2개 위치의 토사는 유류로 심하게 오염되어 있어 현장의 특정지역으로 반출하여 폐기해야 하는 것으로 판단하였다. 토양오염우려수준인 1개 위치의 토사에 대하여 성토재로서의 활용가능성을 확인하기 위하여 성토 안정성에 대한 해석을 수행하였으며 성토재로 사용할 수 있는 것으로 판단하였다.

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High-k 감지막 평가를 통한 고성능 고감도의 Electrolyte-Insulator-Semiconductor pH센서 제작 (Study of High-k Sensing Membranes for the High Quality Electrolyte Insulator Semiconductor pH Sensor)

  • 배태언;장현준;조원주
    • 한국전기전자재료학회논문지
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    • 제25권2호
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    • pp.125-128
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    • 2012
  • We fabricated the electrolyte-insulator-semiconductor (EIS) devices with various high-k sensing membranes to realize a high quality pH sensor. The sensing properties of each high-k dielectric material were compared with those of conventional $SiO_2$ (O) and $SiO_2/Si_3N_4$ (ON) membranes. As a result, the high-k sensing membranes demonstrated better sensitivity and stability than the O and ON membranes. Especially, the $SiO_2/HfO_2$ (OH) stacked layer showed a high sensitivity and the $SiO_2/Al_2O_3$ (OA) stacked layer exhibited an excellent chemical stability. In conclusion, the high-k sensing membranes are expected to have excellent operating characteristics in terms of sensitivity and chemical stability for the biosensor application.

보수성 아스팔트 콘크리트의 특성에 관한 연구 (A Study on Properties of Retentive Asphalt Concrete)

  • 장석수;이승한;정용욱
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.565-568
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    • 2006
  • This study was retentive material into the porosities of the permeable asphalt concrete, we developed retentive asphalt concrete which can absorb water in rain and decrease the temperature of the pavement through the vaporization of rainwater. The experimental results showed that the maximum stability appeared in the 5.0% types of both AP-5 and SBS PMA. Between these two types, the maximum stability of the asphalt with AP-5 was 480kg, which means it met the stability requirement for walkways but didn't meet the requirement for roadways. On the other hand, the maximum stability of the asphalt concrete with SBS PMA was 676kg, which was 176 kg higher than the requirement for roadways(500kg) and satisfy the requirement of KS. The retentive material was 56.4% in the type of the retentive material with 30% diatomaceous earth, 66.6% in 50% type, 87.5% in 70% type. In the aspect of thermal properties, the retentive asphalt concrete can lower the surface temperature by about 15 degrees lower than the normal asphalt concrete can. This effect could be made by the evaporation cooling effect and the surface albedo. It should be noted that the evaporation cooling effect cools it by about 10 degrees and the surface albedo by about 5 degrees.

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Impact of carbon dioxide on the stability of the small-scale structures by trapping the material properties

  • Zhou, Yunlong;Wang, Jian
    • Advances in nano research
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    • 제13권1호
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    • pp.1-12
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    • 2022
  • The existence of active material in the environment causes the small-scale systems to be sensitive to the actual environment. Carbon dioxide is one of the active materials that exists a lot in the air conditions of the living environment. However, in some applications, the carbon dioxide-coated is used to improve the performance of systems against the destructive factors such as the corrosion; nevertheless, in the current research, the stability analysis of a carbon dioxide capture mechanism-coated beam is investigated according to the mathematical simulation of a rectangular composite beam utilizing the modified couple stress theory. The composite mechanism of carbon dioxide trapping is made of a polyacrylonitrile substrate that supports a cross-link polydimethylsiloxane gutter layer as the carbon dioxide mechanism trapping. Three novel types of carbon dioxide trapping mechanism involving methacrylate, poly (ethylene glycol) methyl ether methacrylate, and three pedant methacrylates are considered, which were introduced by Fu et al. (2016). Finally, according to introducing the methodology of carbon dioxide (CO2) trapping, the impact of various effective parameters on the stability of composite beams will be analyzed in detail.

A Study on the Long-Term Integrity of Polymer Concrete for High Integrity Containers

  • Young Hwan Hwang;Mi-Hyun Lee;Seok-Ju Hwang;Jung-Kwon Son;Cheon-Woo Kim;Suknam Lim
    • 방사성폐기물학회지
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    • 제21권3호
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    • pp.411-417
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    • 2023
  • During the operation of a nuclear power plant (NPP), the generation of radioactive waste, including dry active waste (DAW), concentrates, spent resin, and filters, mandates the implementation of appropriate disposal methods to adhere to Korea's waste acceptance criteria (WAC). In this context, this study investigates the potential use of polymer concrete (PC) as a high-integrity container (HIC) material for solidifying and packaging these waste materials. PC is a versatile composite material comprising binding polymers, aggregates, and additives, known for its exceptional strength and chemical stability. A comprehensive analysis of PC's long-term integrity was conducted in this study. First, its compressive strength, which is crucial for ensuring the structural stability of HICs over extended periods, was evaluated. Subsequently, the resilience of PC was tested under various stress conditions, including biological, radiological, thermal, and chemical stressors. The findings of this study indicate that PC exhibits remarkable long-term properties, demonstrating exceptional stability even when subjected to diverse stressors. The results therefore underscore the potential viability of PC as a reliable material for constructing high-integrity containers, thus contributing to the safe and sustainable management of radioactive waste in NPPs.