• 제목/요약/키워드: LB method

검색결과 346건 처리시간 0.02초

LB-DECK를 이용한 철근콘크리트바닥판의 펀칭전단강도 (Punching Shear Strength of Reinforced Concrete Bridge Decks with LB-DECK)

  • 윤석구;이재홍;조선규;정재동;원용석
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.390-393
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    • 2006
  • LB-DECK is used for both of permanent formwork and structural component with cast-in place concrete of concrete bridge decks. Current Korean design code recommends that concrete bridge deck with precast concrete panels have to be designed only using conventional flexural design method and does not allow the empirical design method which is based on punching shear strength of bridge deck. This paper present experimental test results of punching shear strength of concrete bridge decks with LB-DECKs. Six full-scaled concrete bridge decks, which are designed with the empirical design method, are fabricated with variation of girder spacings. Test results are presented in the paper and compared with the code predictions of ACI 318, CEB-FIP MC90. Based on the test results, it is proposed that LB-DECK is suitable to apply the empirical design method for concrete bridge decks.

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인지질 화합물의 나노 Langmuir-Blodgett막의 전기화학적 특성에 관한 연구 (A Study on the Electrochemical Characteristics of Langmuir-Blodgett Nano-Films of Phospholipid Compound)

  • 정아진;박근호
    • 한국응용과학기술학회지
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    • 제29권2호
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    • pp.311-316
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    • 2012
  • 우리는 순환전압전류법에 의한 LB 필름에 대한 전기화학적 특성을 조사하였다. 인지질 화합물은 ITO glass에 Langmuir-Blodgett법을 사용하여 제막하였다. 0.5, 1.0, 1.5 및 2.0 N $NaClO_4$ 용액에서 3 전극 시스템 (Ag/AgCl 기준전극, 백금선 카운터 전극 및 LB 필름이 코팅된 ITO 작업전극)으로 순환전압전류법을 사용하여 전기화학적 측정을 시도하였다. 측정 범위는 연속적으로 1650 mV로 산화시키고, 초기전위인 -1350 mV로 환원시켰다. 그 결과, 인지질 화합물의 LB 필름은 순환전압전류도표로부터 오직 산화전류로 인한 비가역공정으로 나타났다. LB 필름의 확산계수(D) 효과는 인지질 화합물 양의 증가로 인하여 감소하였다.

Al/LB/Al, Au/LB/AU 전극구조에서 Arachidic Acid L-B막의 전기적 특성에 관한 비교 연구 (A Comparative Study of The Electrical Properties of Arachidic Acid L-B Film in the Al/LB/Al and Au/LB/Au Electrode Structures)

  • 오세중;김형석;이창희;김태완;김정수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1993년도 추계학술대회 논문집
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    • pp.112-115
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    • 1993
  • We have studied a property of arachidic acid Langmuir-Blodgett films at room temperature with two different electrodes ; Al/LB/Al and Au/LB/Au. Since a natural oxide layer is formed on top of the Al electrode, the appropriate structure of AL/LB/Al is Al/Al$_2$O$_3$/LB/Al. To obtain a property of Pure LB film, Aua/LB/Au structure was made. In Al/Al$_2$O$_3$/LB/Al structure, a conductivity of 3.7${\times}$10$\^$-14/ S/cm was obtained by using current-voltage(I-V) characteristics. In Au/LB/AU structure, however, I-V curve was not able to be measured because of short current even in 51 layers of the LB film. A status of defects in the film was confirmed by copper decoration method. We have clearly seen a rather big difference of defect in those two above structures.

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Arachidic acid와 Stearic acid의 누적전이와 전기특성 (Deposition Transfer and Electrical Properties of Arachidic acid and Stearic acid)

  • 최영일;송진원;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.764-767
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    • 2001
  • Because using LB method, result that produce Arachidic acid and Stearic acid LB film and measure the accumulation characteristic and electrical characteristic is as following. Organic monolayers of surface of the water compression each 9 layer's LB film to slide glass and manufactured MIM device compressing molecular film only. Could confirm that accumulation was good seeing as absorption coefficient and SEM picture, AFM picture that prevent manufactured LB films. Formation of domain of coexistence form that prevent LB film is indefinite and distinction of border side was not clear, and could know that roughness appears greatly. Obtained current by applied voltage could know that is proportional almost, though Arachidic acid appeared as bulk of current that happen in equaler certification voltage than Stearic acid is less, this alkyl chain longer Arachidic acid that serving relations special quality is superior know can .

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Moving wall형 LB법으로 제작된 MLS DLPC LB 박막의 제작과 캐패시턴스 특성 (Capacitance properties of DLPC LB films with MLS structure fabricated by moving wall type method)

  • 이우선;정용호;손경춘
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1297-1299
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    • 1998
  • LB layers of L-$\alpha$-DLPC deposited by LB method were deposited onto n-type silicon wafer as Z-type film. Films made up of 8, 16 layers of lipid with long alkyl chain and the thickness of monolayer and multilayers was determined by ellipsometry. It was deposited Ag and Al onto LB layers and silicon wafer for electrode and small electrode exhibit high capacitance and low leakage current. The C-V curves of the MLS capacitor shows very high saturation value of capacitance. And cross-sectional SEM image of MLS capacitor indicated the presence of pore with Al electrode and we found that the Ag is good for electrode metal.

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LB 초박막 커패시터의 제작 및 특성 (II) (Fabrication and Characteristics of LB Ultra-thin Film Capacitor (II))

  • 유승엽;박재철;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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    • pp.244-247
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    • 1996
  • We had experiment using LB method that can fabricate molecular order ultra-thin film below 100${\AA}$. LB method has known as main technology of information society in 21C, because it is not only free orientation and alignment of molecular but also ability of thickness control as molecular order. In this paper, the fabricated condition and physical properties of functional ultra-thin film of molecular order was investigated and highly efficient ultra-thin film capacitor was fabricated by using ultra-thin LB film for application as electronic device. Possibility of ultra-thin film capacitor was researched by analyzing and measuring electrical properties. Polyimide ultra-thin LB film capacitor was fabricated, ensured theoretically and experimentally its possibility in range of 10Hz∼lMHz through its frequency characteristics.

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유기 박막의 전기적 특성 및 가스 반응 특성 (Gas Response and Electrical Properties of Organic Ultra-thin Films)

  • 박재철
    • 한국전기전자재료학회논문지
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    • 제11권10호
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    • pp.820-825
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    • 1998
  • We deposited stearic acid LB films by using Langmuir-Blodgett (LB)method and investigated anisotropy electrical conduction characteristics by I-V measurement for horizontal direction and vertical direction. Also, we measured gad response between deposited LB films and organic gas for various temperature(0~8$0^{\circ}C$) by 9MHz At-cut quartz crystal microbalance. The LB films have electrical conduction characteristics such as semiconducting and insulating properties. The is, the conductivity of LB films for the horizontal and vertical direction is about 10\ulcornerS/cm and 10\ulcorners/cm, respectively. the frequency shift of stearic acid LB films for the organic gases depended on the mass change by the surface adsorption and the inner penetration to the sensing films. The resonant frequency shift of the quartz crystal microbalance for temperature properties of LB films is thought to the effect of the rearrangement or the damage pf LB films above the melting point and the mobility increasement of the organic gas by the temperature rising.

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수정진동자의 임피던스 해석에 의한 LB막의 전기적 특성 (Electric Properties of LB Films using Impedance Analysis of Quartz Crystal)

  • 진철남;김경환;유승엽;권영수
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권7호
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    • pp.503-507
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    • 1999
  • Quartz crystal in contact with viscoelastic medium was described directly in terms of the electrical equivalent circuit of the system. Stearic acid was used as viscoelastic medium and deposited on the surface of quartz crystal using the Langmuir-Blodgett(LB) method. Impedance properties of quartz crystal coated with LB films which were investigated by using admittance diagram and $Ζ-\theta$ plot a method of impedance analysis. When stearic acid LB film was deposited on the surface of quartz crystal, resonant frequency of quartz crystal was changed about 100 Hz/layer. This result illustrates the ability of the sensor system to detect small amounts of special gas in air.

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Slip flow 해석을 위한 격자볼츠만 방법의 곡면처리기법 (CURVED BOUNDARY TREATMENT OF THE LATTICE BOLTZMANN METHOD FOR SLIP FLOW SIMULATIONS)

  • 정남균
    • 한국전산유체공학회지
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    • 제19권3호
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    • pp.77-84
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    • 2014
  • The lattice Boltzmann (LB) method has been used to simulate rarefied gas flows in a micro-system as an alternative tool. However, previous results were mainly focused on a simple geometry with flat walls because the LB method is modeled on uniform Cartesian lattices. When previous boundary conditions for the microflows are applied to curved walls, the use of them requires approximation of the curved boundary by a series of stair steps, and introduces additional errors. For macroflows, no-slip curved wall boundary treatments have been developed remarkably in order to overcome these limits. However, the investigations for the slip curved wall boundary have rarely been performed for microflows. In this work, a curved boundary treatment of the LB method for a slip flow has been introduced. The results of the LB method for 2D microchannel and 3D microtube flows are in excellent agreement with the analytical solutions.

Merocyanine dye LB막의 표면이미지 및 광학적 특성 연구 (Study on morphology and OPtical Characteristics of merocyanine dye LB films)

  • 류길용;박상현;박재철;권영수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.136-138
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    • 2005
  • Merocyanine dye (MD) has been extensively investigated due to its marked potential application to photo-electric devices. We fabricated the number of layers to control its optical characteristics using the Langmuir-Blodgett (LB) method. We evaluated the morphology and optical characteristics of MD LB films using Atomic Force Microscopy (AFM) and UV spectroscopy, PL spectroscopy. As a result, we obtained the quantitative morphology and optical characteristics of LB films from controlling the deposided layers.

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