• 제목/요약/키워드: layer

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Study on the eletronic absorption and surface morphology of phthalocyanine double layer thin films

  • 허일수;류일환;홍다정;임상규
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.337-337
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    • 2011
  • The elecronic absorption and surface morphology evolution of two types of molecular double layer thin films, copper phthalocyanine(CuPc) layer deposited on top of chloro[subphtalocyaninato]boron(III) (SubPc) layer, denoted as SubPc/CuPc, and vice versa, at various thicknesses were invertigated using ultraviolet(UV)-visible spectroscopy and atomic force microscopy (AFM). Both types of double layer structures showed similar broadened absorption patterns in UV-visible region which were well consistent with fitted spectra by a simple linear combination of single layer absorption spectra of two materials. In contrast, the surface morphology of double layer structures was dependent on the order of deposition. For CuPc/SubPc structures, the surface morphology was characterized by elongated grains, characteristic of SubPc thin films, indicating the morphological influence of underlying CuPc layer on subsequent SubPc layer was not large. For SubPc/CuPc structures, however, the underlying SubPc layer acted as a morphological template for the subsequently deposited CuPc layer. It was also observed that the grain size of CuPc layer varied by the thickness of underlying SubPc layer.

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실리콘 질화막의 산화 (The oxidation of silicon nitride layer)

  • 정양희;이영선;박영걸
    • E2M - 전기 전자와 첨단 소재
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    • 제7권3호
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    • pp.231-235
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    • 1994
  • The multi-dielectric layer $SiO_2$/$Si_3{N_4}$/$SiO_2$ (ONO) is used to improve charge retention and to scale down the memory device. The nitride layer of MNOS device is oxidize to form ONO system. During the oxidation of the nitride layer, the change of thickness of nitride layer and generation of interface state between nitride layer and top oxide layer occur. In this paper, effects of oxidation of the nitride layer is studied. The decreases of the nitride layer due to oxidation and trapping characteristics of interface state of multi layer dielectric film are investigated through the C-V measurement and F-N tunneling injection experiment using SONOS capacitor structure. Based on the experimental results, carrier trapping model for maximum flatband voltage shift of multi layer dielectric film is proposed and compared with experimental data. As a results of curve fitting, interface trap density between the top oxide and layer is determined as being $5{\times}10^11$~$2{\times}10^12$[$eV^1$$cm^2$].

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김해에서 관측한 접지역전층의 특성에 관한 연구 (A Study on the Characteristics of Inversion Layer Observed at Kimhae)

  • 박종길;원경미
    • 한국환경과학회지
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    • 제3권4호
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    • pp.305-315
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    • 1994
  • The field observation was carried out to investigate the characteristics of surface inversion layer at Kimhae using the feild observed date and upper layer meteorological data during 4-5 February 1993. The results of the study can be summarized as follows : The maximum height of surface inversion layer observed at Kimhae is 193m and the height of upper level inversion layer ranges from 2nm to 300m. The surface weather elements was influenced the formation of surface inversion layer. According to the pasquill stability and time variation of temperature with height, both the surface heating from insolation and the disturbance of upper level of inversion layer was influenced the disappearance of inversion layer. And the stability of surface temperature inversion layer generally belongs to the class of F, that of upper level temperature inversion layer commonly to the class of E.

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전계방출광원용 아노드 난반사 연구 (Reporting on the High Efficiency of Anode Phosphor Electrode for Filed Emission Lamp - Metal Layer)

  • 윤한나;김윤일;김대준;김광복
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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    • pp.29-32
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    • 2008
  • The electron charging and degradation of anode phosphor layers are showed major problems in high electric field with anode electrode of field emission devices. An AI metal layer on the phosphor layer may get rid of these problems. This Hetero-metal-oxide phosphor layer are formed with the roughness of phosphor surface layer without interlayer and cannot be given rise to enhance the luminance efficiency. In order to enhance the brightness, an anode layer need to be flated between phosphor layer and AI metal layer in anode electrode. After optimizing the anode phosphor layer, an anode layer with AI metal and inter layer increased the brightness and luminescence efficiency 1.2 times more than only phosphor laver in anode.

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복합열처리(複合熱處理)한 연강(軟鋼)의 표면경화(表面硬化)에 관한 연구 (A Study on Surface Case Hardening of Blend Heat Treated Mild Steel)

  • 정인상;전해동;신석목
    • 열처리공학회지
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    • 제5권1호
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    • pp.23-31
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    • 1992
  • It is investigated that Fe-C-N compound layer, defusion layer, and induction hardened layer produced by nitrocarburizing blend heat treatment in austenitic temperature with high frequency induction heating of mild steel specimen sprayed sursulf salt-bath. As the temperature of blend-heat treatment got increased, the thickness and hardness of compound layer and diffusion layer were increased. Compound layer(max. $35{\mu}m$), diffusion layer (max. 2.5mm) and induction hardened layer were gained in the shortest time 10 sec and in the case of $1000^{\circ}C$ total hardness depth of those was about 3.5mm. When the blend-heat treated specimen was reheated, maximum hardness of compound layer was dropped more than that of the reheated compound layer after sursulf treated, whereas hardness of diffusion layer was increased.

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다층 고온 초전도 케이블의 전류 분포 및 교류손실 해석 (Current Distribution and Numerical Analysis of AC Losses on Multi-Layer HTS Cable)

  • 김영석;이병성;장현만;곽민환;김상현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.452-455
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    • 2000
  • Superconducting power cable is one of the most promising energy application of high-T$_{c}$ superconductors (HTS). A prototype HTS cable have been constructed multi-layer cable using Bi-2223 tape and tested. The AC transport losses under self field were investigated at 77K on the 19 filamentary tape and multi-layer HTS cables. And we carried out numerical analysis using bean model. The result shows that the total transport current of HTS cable in L$N_2$ was 475[A], and transport current passed through almost the outer layer (2-layer). Also, AC transport losses in outer layer of HTS cable was proportion to I$^2$ and higher than losses of inner layer. In case of Ip=Ic, calculated numerical loss density was concentrated on the edge of tape and most of loss density in cable was distributed outer layer more than inner layer. As magnetic distribution was concentrated on outer layer.r.

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Numerical simulation of air layer morphology on flat bottom plate with air cavity and evaluation of the drag reduction effect

  • Hao, W.U.;Yongpeng, O.U.
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제11권1호
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    • pp.510-520
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    • 2019
  • To investigate the morphology characteristics of air layer in the air cavity, a numerical method with the combination of RANS equations and VOF two-phase-flow model is proposed for a plate with air cavity. Based on the model above, the dynamic and developmental process of air layer in the air cavity is studied. Numerical results indicate that the air layer in the plate's air cavity exhibits the dynamic state of morphology and the wavelength of air layer becomes larger with the increasing speed. The morphology of air layer agrees with the Froude similarity law and the formation of the air layer is not affected by the parameters of the cavity, however, the wave pattern of the air layer is influenced by the parameters of the cavity. The stable air layer under the air cavity is important for the resistance reduction for the air layer drag reduction.

초전도 테이프 제작을 위한 니켈기판 상의 산화물 박막 증찰 (Study on Depositing Oxide Films on Ni Substrate for Superconducting Tape)

  • 김호섭;;고락길;정준기;하홍수;송규정;박찬
    • 한국전기전자재료학회논문지
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    • 제17권12호
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    • pp.1356-1361
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    • 2004
  • High temperature superconducting coated conductor has a structure of ///. The buffer layer consists of multi-layer, this study reports the deposition method and optimal deposition conditions of YSZ(Yttria-stabilized zirconia) layer which plays a important part in preventing the elements of substrate from diffusing into the superconducting layer. YSZ layer was deposited by DC reactive sputtering technique using water vapor for oxidizing deposited elements on substrate. To investigate optimal thickness of YSZ film, four YSZ/CeO$_2$/Ni samples with different YSZ thickness(130 nm, 260 nm, 390 nm, and 650 nm) were prepared. The SEM image showed that the surface of YSZ layer was getting to be rougher as YSZ layer was getting thicker and the growth mode of YSZ layer was columnar grain growth. After CeO$_2$ layer was deposited with the same thickness of 18.3 nm on each four samples, YBCO layer was deposited by PLD method with the thickness of 300 nm. The critical currents of four samples were 0, 6 A, 7.5 A, and 5 A respectively. This shows that as YSZ layer is getting thicker, YSZ layer plays a good role as a diffusion barrier but the surface of YSZ layer is getting rougher.

효율적인 Scalable Video Streaming을 위한 Cross Layer Optimization (Cross Layer Optimization for Scalable Video Streaming)

  • 윤민영;조희영;서덕영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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    • pp.352-354
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    • 2005
  • As further Studies on 4th generation mobile telecommunication are progressed, the importance of a Cross-Layer is being increased. However, it has focused on coordination model only between MAC layer and PHY layer. It is necessary to expand into II' layer and upper layers. In this paper, we introduce a Cross-layer optimization which can be used to transmit video data with effect by managing resources among layers. It can gives further more adaptive method to solve QoS model problem than single layer.

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Analysis on Current Distribution of Four-Layer HTSC Power Transmission Cable with a Shield Layer

  • Lim Sung-Hun
    • Journal of Electrical Engineering and Technology
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    • 제1권3호
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    • pp.308-312
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    • 2006
  • The inductance difference between conducting layers of high-Tc superconducting (HTSC) power transmission cable causes the current sharing of each conducting layer to be unequal, which decreases the current transmission capacity of HTSC power cable. Therefore, the design for even current sharing in HTSC power transmission cable is required. In this paper, we investigated the current distribution of HTSC power cable with a shield layer dependent on the pitch length and the winding direction of each layer. To analyze the effect of the shield layer on the current sharing of the conducting layers of HTSC power cable, the current distribution of HTSC power cable without a shield layer was compared with the case of HTSC power cable with a shield layer. It could be found through the analysis from the computer simulations that the shield layer of HTSC power cable could be contributed to the improvement of current distribution of conducting layers at the specific pitch length and the winding direction of conducting layer. The result and discussion for the current distribution calculated for HTSC power transmission cable with a shield layer were presented and compared with the cable without a shield layer.