• Title/Summary/Keyword: High performance

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Recent Advances in High-performance Functional Ceramics using 3D Nanostructuring Techniques (3차원 나노구조화 기술을 이용한 고성능 기능성 세라믹 연구개발 동향)

  • Ahn, Changui;Park, Junyong;Jeon, Seokwoo
    • Ceramist
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    • v.22 no.3
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    • pp.230-242
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    • 2019
  • Functional ceramics are widely utilized in a variety of application fields such as structural materials, sensors, energy devices, purification filter and etc due to their high strength, stability and chemical activity. With the breakthrough development of nanotechnology, many researchers have studied new types of nanomaterials including nanoparticle, nanorod, nanowire and nanoplate to realize high-performance ceramics. Especially several groups have focused on the 3D nanostructured ceramics because of their large surface area, efficient load transfer, ultra-fast ion diffusion and superior electrical (or thermal) conductivity. In this review, we introduce the reported fabrication strategies of the 3D nanostructured and functional ceramics, also summarized the 3D nanostructured ceramic based high-performance applications containing photocatalysts, structural materials, energy harvesting and storage devices.

Stable In-reactor Performance of Centrifugally Atomized U-l0wt.%Mo Dispersion Fuel at Low Temperature

  • Kim, Ki-Hwan;Kwon, Hee-Jun;Park, Jong-Man;Lee, Yoon-Sang;Kim, Chang-Kyu
    • Nuclear Engineering and Technology
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    • v.33 no.4
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    • pp.365-374
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    • 2001
  • In order to examine the in-reactor performance of very-high-density dispersion fuels for high flux performance research reactors, U-l0wt.%Mo microplates containing centrifugally atomized powder were irradiated at low temperature. The U-l0wt.%Mo dispersion fuels show stable in- reactor irradiation behaviors even at high burn-up, similar to U$_3$Si$_2$ dispersion fuels. The atomized U-l0wt.%Mo fuel particles have a fine and a relatively uniform fission gas bubble size distribution. Moreover, only one of third of the area of the atomized fuel cross-sections at 70a1.% burn-up shows fission gas bubble-free zones, This appears to be the result of segregation into high Mo and low Mo.

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An Experimental Study on the Various Factors affect the Explosive Spalling of High Performance Concrete (고성능 콘크리트의 폭열에 미치는 각종 요인에 관한 실험적 연구)

  • Na, Chul-Sung;Shin, Kwan-Soo;Lee, Eui-Bae;Kwon, Young-Jin;Kim, Gyu-Yong;Kim, Moo-Han
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2006.04a
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    • pp.172-175
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    • 2006
  • Recently, fire resistance of high performance concrete for explosive spatting was issued as high performance concrete was vulnerable to the explosive spatting in initial fire. Therefore, This study is willing to propose fundamental data for quick and accurate diagnosis of deteriorated concrete structure by fire damage with making variable concrete test specimen, exposing high temperature environment, observing the explosive spatting and examining engineering property.

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Optimal Shape Deign of a High Speed Switched Reluctance Motor Vsing Fuzzy Set Theory (퍼지 이론을 이용한 고속 회전용 스위치드 리럭턴스 모터의 형상 최적 설계)

  • Choi, Chang-Hwan;Yoo, Jae-Sun;Park, Kyi-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.10
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    • pp.659-664
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    • 2000
  • This paper presents a new design method for improving the torque performance of a switched reluctance motor (SRM) for high speed applications. The drawback of the conventional design method based on the overall static average torque maximization is that the torque control performance is degraded at high speed. On the other hand, the proposed method optimizes the torque profile by diving it into several regions so that it is suitable for high speed operation. This multi-objective optimization problem is solved by using a fuzzy optimization algorithm which incorporates a finite element method. The torque performance of the motor for various speed ranges is investigated and the optimally designed motor show a better performance at high speed.

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Fire Performance of 100MPa High Strength Concrete with Fire Protection Cover (100MPa급 내화피복 고강도 콘크리트의 내화성능 인증)

  • Song, Young-Chan;Kim, Yong-Ro;Kim, Ook-Jong;Lee, Do-Bum
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05b
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    • pp.21-22
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    • 2010
  • In this research, the purpose is to share fire resistance method to secure 3 hours fire resistance performance which is regulation noticed by Ministry of Land, Transport and Maritime Affairs for 100MPa high strength concrete which is predicted to apply to high rise building and to propose the guideline for confirmation of fire resistance performance of high strength concrete member to which fire resistance method is applied and field application in advance.

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A Study on the Development of High Performance Interlayer Soundproofing Material Considering Long Term Deflection (장기처짐을 고려한 고성능 층간차음재 개발에 관한 연구)

  • Yang, Jin-Kook;Hong, Seong-Wook;Kang, Hyun-woo;Park, Young-Duk;Lim, Nam-Gi
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.107-108
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    • 2019
  • The interlayer noise of the apartment house is a typical problem that reduces the quality of the residential environment. Therefore, many researchers have developed soundproofing materials that blocks noise between floors. However, most development technologies do not have the noise cut-off effect felt by residents, and may also have a defect in long-term deflection. In this respect, this study developed high-performance interlayer soundproofing material that can overcome existing problems. The developed technology has the noise reduction effect experienced by the residents and it has high durability without long-term deflection. Therefore, high-performance interlayer soundproofing material is expected to contribute to reducing disputes over noise between floors of apartment residents.

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Effect of Aggregates Kinds and Superplasticizer on Fundamental Properties of Ultra High Performance Concrete (골재 종류 및 SP제 변화가 초고성능 콘크리트 기초적 특성에 미치는 영향)

  • Lee, Hong-Kyu;Jung, Sang-Woon;Jo, Man-Ki;Han, Dong-Yeop;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.55-56
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    • 2014
  • In this research, the effect of types of aggregate and SP on fundamental properties of ultra-high performance concrete of 80 MPa of compressive strength was evaluated to provide solution for high cost of ultra-high performance concrete. As the results of a series of tests, the mixture using limestone and silica aggregates showed improved workability rather than the mixture using granite aggregate. For compressive strength of UHPC, the UHPC mixtures using limestone and silica aggregates showed higher compressive strength than the UHPC mixture using granite aggregate while all mixtures satisfied target compressive range.

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Considerations of Sustainable High-rise Building Design in Different Climate Zones of China

  • Wan, Kevin K.W.;Chan, Man-Him;Cheng, Vincent S.Y.
    • International Journal of High-Rise Buildings
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    • v.1 no.4
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    • pp.301-310
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    • 2012
  • Buildings, energy and the environment are key issues that the building professions and energy policy makers have to address, especially in the context of sustainable development. With more tall buildings constructed in China, the impact on energy consumption and carbon emission would be great from buildings (2% increase of carbon dioxide annually between 1971 and 2004). The imperative was to investigate the building energy performance of high-rise in different climate zones and identify the key design parameters that impose significantly influence on energy performance in sustainable building design. Design implications on glazing performance, sizing of the ventilation fans, renewable energy application on high-rise building design are addressed. Combination of effective sustainable building design strategies (e.g., building envelope improvement, daylight harvesting, advanced lighting design, displacement ventilation, chilled ceiling etc.) could contribute more than 25% of the total building energy consumption compared to the international building energy code.

The Evaluation of Flexural Performance of Beam of Repair as High Toughness Cementitious Composites (고인성 시멘트 복합체에 의해 보수된 보 부재의 내하력 평가)

  • Ryu, Gum-Sung;Koh, Kyung-Taeg;Park, Jung-Jun;Ahn, Ki-Hong;Yoon, Pil-Yong;Kim, Jin-Su
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.625-628
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    • 2006
  • In this study, the beam which is repaired as high toughness cementitious composites evaluated on flexural performance. As for the test results, it was found that high toughness performance of beams of the repair as high toughness cementitious composites showed more better than the existing repair method and demonstrated about 95% semi-reinforcement to compare with reinforcement of carbon fiber sheets of one layer without interface and brittle failure. Therefore, appling on using PVA fiber reinforced high toughness cementitious composites, the repaired concrete structures can be increased to flexural performance.

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Durability of high performance sandcretes (HPS) in aggressive environment

  • Benamara, Dalila;Tebbal, Nadia;Rahmouni, Zine El Abidine
    • Advances in concrete construction
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    • v.8 no.3
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    • pp.199-206
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    • 2019
  • High performance sandcretes (HPS) are new concretes characterized by particles having a diameter less than 5 mm, as well as very high mechanical strength and durability. This work consists in finding solutions to make sandcretes with good physico-mechanical and durability properties for this new generation of micro-concrete. However, upgrading ordinary sandcrete into high performance sandcrete (HPS) requires a thorough study of formulation parameters (equivalent water/binder ratio, type of cement and its dosage, kind and amount of super plasticizer, and gravel/sand ratio). This research study concerns the formulation, characterization and durability, in a sulphate environment, of a high performance sandcrete (HPS), made from local materials. The obtained results show that the rheological properties of fresh concrete and mechanical strength differ with the mineralogy, density and grain size distribution of sands and silica fume used.