• 제목/요약/키워드: Materials property

검색결과 4,149건 처리시간 0.032초

철도차량에 적용될 복합재료의 저속충격특성에 관한 연구 (A Study on the Impact Characteristics of the Composite Materials for Low Velocity to Be Applied a Rail Vehicle)

  • 류충현;이영신;김재훈;나재연;조정미;박병준
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(II)
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    • pp.851-856
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    • 2002
  • In this study, the property against low velocity of the compesite material, which will be applied a rail vehicle, is shown using experiment and a finite element code. The property can be denoted the resistance of impact force, which is defined by maximum impact force over damage area. A damage propagation model is necessary to estimate accurately the impact property of a composite material through FEM code.

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유기농 자재의 연용이 토양의 이화학적 성질과 토마토의 생육, 수량 및 체내성분에 미치는 영향 (Effect of Continuous Application of Organic Farming Materials on the Soil Physicochemistry Property and Plant Growth, Yield and Components of Tomato)

  • 오주성;이종성;강경희;김회태;정원복;정순재
    • 한국유기농업학회지
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    • 제9권1호
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    • pp.75-89
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    • 2001
  • This study the effects of the application of organic farming materials on the soil Physicochemistry property and plant growth, yield and components of Tomato were compared with conventional culture. The results obtained from the experiment are summarized as follows : 1. The effect of soil chemical properties after application organic farming materials, The amounts of pH and O.M. in N, P, K treated plot were few of change, To the contrary, fermentation compost and microorganisms fermentation compost treated plot were some increase, Amount of $P_2$$O_{5}$, Ca and K increase in comparison with the N, P, K treated plot. 2. Changes of soil microbial after application organic farming materials, The number of bacteria, actinomycetes and fungi in N, P, K treated plot were appeared definite direction. to the contrary, The number of bacteria and actimycetes in fermentation compost and microorganisms fermentation compost treated plot showed the increased tendency, The number of fungi showed the decreased tendency. 3. Effect of organic farming materials application on the growth and yield of tomato was superior in order of microorganisms fermentation compost plot〉 chemical fertilizers plot〉 fermentation compost plot. especially, chicken manure + microorganisms fermentation compost treated plot was the highest. 4. Effect of organic farming materials application on the components of tomato were not different.

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Hastelloy X의 고온열화에 따른 미세구조 및 고온압축특성 (Microstructural Analysis and High Temperature Compression Behavior of High Temperature Degradation on Hastelloy X)

  • 김길수;조태선;서영익;류우석;김영도
    • 한국재료학회지
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    • 제16권5호
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    • pp.318-322
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    • 2006
  • Short-term high temperature degradation test was conducted on Hastelloy X, a candidate tube material for high temperature gas-cooled reactors (HTGR), to evaluate the variation of microstructure and mechanical property in air at $1050^{\circ}C$ during 2000 h. The dominant oxide layer was Cr-oxide and a very shallow Cr-depleted region was observed below the oxide layer. At the beginning of degradation, the island shape $M_6C$ precipitate (M=Mo-rich, Fe, Ni, Cr) was observed in matrix region. After 2000 h degradation, precipitate shape was changed to the chain shape and increased amount of precipitate. These results influenced mechanical property of the specimen which exposed in high temperature. Yield strength was decreased from 115MPa to 89 MPa after 24 h and 2000 h exposure, respectively.

Performance-determining factors in flexible transparent conducting single-wall carbon nanotube film

  • Song, Young Il;Lee, Jung Woo;Kim, Tae Yoo;Jung, Hwan Jung;Jung, Yong Chae;Suh, Su Jeung;Yang, Cheol-Min
    • Carbon letters
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    • 제14권4호
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    • pp.255-258
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    • 2013
  • Flexible transparent conducting films (TCFs) were fabricated by dip-coating single-wall carbon nanotubes (SWCNTs) onto a flexible polyethylene terephthalate (PET) film. The amount of coated SWCNTs was controlled simply by dipping number. Because the performance of SWCNT-based TCFs is influenced by both electrical conductance and optical transmittance, we evaluated the film performance by introducing a film property factor using both the number of interconnected SWCNT bundles at intersection points, and the coverage of SWCNTs on the PET substrate, in field emission scanning electron microscopic images. The microscopic film property factor was in an excellent agreement with the macroscopic one determined from electrical conductance and optical transmittance measurements, especially for a small number of dippings. Therefore, the most crucial factor governing the performance of the SWCNT-based TCFs is a SWCNT-network structure with a large number of intersection points for a minimum amount of deposited SWCNTs.

Influence of surface morphology on H2S sensing property of Cu2O thin film deposited by RF magnetron sputtering

  • Hien, Vu Xuan;You, Jae-Lok;Jo, Kwang-Min;Kim, Se-Yun;Lee, Joon-Hyung;Kim, Jeong-Joo;Heo, Young-Woo
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2014년도 추계학술대회 논문집
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    • pp.250-251
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    • 2014
  • This study introduces a simple deposition of $Cu_2O$ thin films with surface morphologies composed of columns, submicron-rods and submicron-branches on glass substrate from metallic Cu targets by tailoring the $Ar/O_2$ ratios during the sputtering. The obtained samples were used to fabricate gas sensor. The $H_2S$ sensing properties of the sensors at working temperatures from $100^{\circ}C$ to $300^{\circ}C$ were studied, in which $Cu_2O$ submicron-branches performed the best sensing property comparing with the rest morphologies. A transformation of $Cu_2O$ to $Cu_2S$ and CuS was consider as a main factor to the sensing mechanism of the sensors.

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