• 제목/요약/키워드: nano-material

검색결과 2,413건 처리시간 0.039초

Thermal buckling of nonlocal clamped exponentially graded plate according to a secant function based refined theory

  • Abdulrazzaq, Mohammed Abdulraoof;Fenjan, Raad M.;Ahmed, Ridha A.;Faleh, Nadhim M.
    • Steel and Composite Structures
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    • 제35권1호
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    • pp.147-157
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    • 2020
  • In the present research, thermo-elastic buckling of small scale functionally graded material (FGM) nano-size plates with clamped edge conditions rested on an elastic substrate exposed to uniformly, linearly and non-linearly temperature distributions has been investigated employing a secant function based refined theory. Material properties of the FGM nano-size plate have exponential gradation across the plate thickness. Using Hamilton's rule and non-local elasticity of Eringen, the non-local governing equations have been stablished in the context of refined four-unknown plate theory and then solved via an analytical method which captures clamped boundary conditions. Buckling results are provided to show the effects of different thermal loadings, non-locality, gradient index, shear deformation, aspect and length-to-thickness ratios on critical buckling temperature of clamped exponential graded nano-size plates.

저온소성 다층 세라믹 기판에 로고스키 코일을 적용한 전류센서에 관한 연구 (Study of amperometric sensor apply a Rogowski Coil on LTCC)

  • 김은섭;문형신;김경민;박성현;신병철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.251-252
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    • 2009
  • 전류에 의한 자속변화를 검출하는 로고스키코일은 자성체를 코어로 이용하는 종전의 변류기 (Current Transformer) 와는 달리 공심이거나 비자성재료를 사용하기 때문에 자기적으로 포화되지 않으므로 일반적으로 디지털 적산 전력량계의 전류센서로 활용되고 있다. 본 연구는 저온소성 다층 세라믹 기판상에 로고스키코일을 적용한 전자식 전력량계의 정밀 전류측정용 센서 개발에 관한 것이며. 3차원 전자기장 해석 프로그램인 MWS를 하여 기판의 소재와 코일의 패턴의 크기 등을 달리하여 그 특성을 알아보고 실제 구현된 센서의 측정된 값과 비교해 보았다.

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탄소 나노 재료 기반의 전기-화학적 구동기 (Nano Carbon Material Based Electrochemical Actuators)

  • 차주영;강인필
    • 한국정밀공학회지
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    • 제28권11호
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    • pp.1251-1258
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    • 2011
  • With the help of nanoscale materials like carbon nanotube (CNT), there is the potential to develop new actuators that will provide higher work per cycle than previous actuator technologies, and generate much higher mechanical strength. In this study, the electrochemical actuation characteristics of nano carbon materials were experimentally studied to develop electrochemical actuators. The electrochemical actuators were composed of aqueous NaCl electrolyte and their actuating electrodes were made of multi-walled carbon nanotube (MWCNT)/polystyrene composite and graphene respectably. Actuation is proportional to charging transfer rate, and the electrolysis with an AC voltage input has very complex characteristics. To quantify the actuation property, the strain responses and output model were studied based on electrochemical effects between the nano carbon films and the electrolyte.

ZnO 나노파우더 바리스터의 C-V 및 주파수 특성 분석 (Analysis of C-V and Frequency Characteristics of the ZnO nano-powder Varistors)

  • 왕민성;정종엽;송민종;박춘배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.183-184
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    • 2005
  • In this study, our varistors based on M.Matsuoke's composition were fabricated with ZnO nano-powder whose sizes were 50nm and 100nm. Electrical properties of ZnO nano-powder varistors were obtained by capacitance-voltage and frequency-real impedance. nano-powder varistors are indicated the change of the interface defects density $N_t$ at the grain boundaries and the donor concentration $N_d$ in the ZnO grains. Frequency analysis was accomplished to understand the equivalent circuit.

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비휘발성 메모리 소자 응용을 위한 Si-rich 박막을 사용한 Nano-crystal 형성 (Formation of Nano-crystal using Si-rich thin film for Non Volatile Memory Device Application)

  • 장경수;정성욱;김현민;황형선;최석호;이준신
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.128-129
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    • 2005
  • In this research, non-volatile memory effects and nano-crystal creation have been investigated in SiNx containing Si nano-crystals (Si-nc) produced by ICP-CVD and rapid thermal annealing. The quantum dots were created during rapid thermal annealing of Si-rich SiNx thin films. The quantum dot creation was analyzed with photoluminescence spectra, and in case of Si-rich SiNx, it is conformed that the quantum dots are formed easily at 750$\sim$800nm wavelength.

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Back-gate bias를 이용한 SOI nano-wire BioFET의 electrical sensing (Electrical sensing of SOI nano-wire BioFET by using back-gate bias)

  • 정명호;안창근;조원주
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.354-355
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    • 2008
  • The sensitivity and sensing margin of SOI(silicon on insulator) nano-wire BioFET(field effect transistor) were investigated by using back-gate bias. The channel conductance modulation was affected by doping concentration, channel length and channel width. In order to obtain high sensitivity and large sensing margin, low doping concentration, long channel and narrow width are required. We confirmed that the electrical sensing by back-gate bias is effective method for evaluation and optimization of bio-sensor.

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$O_2$ plasma 표면 처리 공정에 의한 SOI nano-wire Bio-FET 소자의 전기적 특성 열화 (Degradation of electrical characteristics in SOI nano-wire Bio-FET devices)

  • 오세만;조원주
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.356-357
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    • 2008
  • The effects of $O_2$ plasma ashing process for surface treatment of nano-wire Bio-FET were investigated. In order to evaluate the plasma damage introduced by $O_2$ plasma ashing, a back-gate biasing method was developed and the electrical characteristics as a function of $O_2$ plasma power were measured. Serious degradations of electrical characteristics of nano-wire Bio-FET were observed when the plasma power is higher than 50 W. For curing the plasma damages, a forming gas anneal (2 %, $H_2/N_2$) was carried out at $400^{\circ}C$. As a result, the electrical characteristics of nano-wire Bio-FET were considerably recovered.

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Effect of Nano-silicate on the Mechanical, Electrical and Thermal Properties of Epoxy/Micro-silica Composite

  • Park, Jae-Jun
    • Transactions on Electrical and Electronic Materials
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    • 제13권3호
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    • pp.153-156
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    • 2012
  • In order to develop electrical insulation materials, epoxy/micro-silica composite (EMC) and epoxy/micro-silica/nano-silicate composite (EMNC) were prepared, and their tensile and flexural strength, AC insulation breakdown strength and thermal conductivity and thermal expansion coefficient were compared. Nano-silicate was prepared in an epoxy matrix by our AC electric field process. All properties of the neat epoxy were improved by the addition of micro-silica, which was improved much further by the addition of nano-silicate to the EMC system.