• 제목/요약/키워드: Barrier Potential

검색결과 653건 처리시간 0.031초

ICT Implementation for Materials Management in Construction Projects: Case Studies

  • Kasim, Narimah
    • Journal of Construction Engineering and Project Management
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    • 제1권1호
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    • pp.31-36
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    • 2011
  • Construction materials usually constitute a major portion of the total cost in a building construction project. Materials management Is made problematic by materials shortages, delays in supply, price fluctuations, damage and wastage, and lack of storage space. Despite the potential benefit of ICT, convincing construction organisations to embrace its use and implementation has proved a difficult task. This study seeks to identify the implementation of ICT for materials management processes in construction projects. The findings from the case studies reveal that the implementation of ICT in the materials management processes for construction projects in Malaysia Is at early stage. Microsoft Excel Spreadsheet and handheld devices are found to be the common ICT tools adopted in the materials management processes. The main barrier is found to be the cost involvement at the initial stage or overall implementation of ICT in the materials management processes. Finally, this paper concludes the finding from interviews towards the ICT implementation of materials management in the construction projects.

Improvement of the On-Current for the Symmetric Dual-Gate TFT Structure by Floating N+ Channel

  • LEE, Dae-Yeon;Hwang, Sang-Jun;Park, Sang-Won;Sung, Man-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.342-344
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    • 2005
  • We have simulated a symmetric dual-gate TFT which has triple floating n+ channel to improve the on-current of the dual-gate TFT. We achieved a low hole concentration at the source and channel junction causes the improvement the potential barrier so that we observed the reduction of the kink-effect. In this paper, we observed the reduction of the kink-effect compared with the conventional single-gate TFT and the improvement of the on-current compared with the conventional dual-gate TFT.

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$TiO_2$의 첨가가 ZnO계 세라믹 바리스타에 미치는 전기적인 영향 (Influence of the Conduction Properties on ZnO-Based Ceramic Varistor with $TiO_2$ Additives)

  • 이상석;장경욱;이준웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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    • pp.234-238
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    • 1987
  • In this paper, the used specimen composition was added basic additives ($Bi_2O_3\;lmol%$, $Sb_2O_3\;lmol%$, CoO 0.5 mol%, MnO 0.5mol%) to ZnO powder, and $TiO_2$ (1,2,3,4 mol%) to the above basic composition. It appears that there are four regions of conduction current depended upon the strength of the applied electric field ; Ohimic region, Poole-Frenkel region, Schottky region and Tunneling region. Increasing of $TiO_2mol%$, the breakdown voltages of ZnO ceramic varistors are decreased. The decrease of breakdown voltages was explained with the decrease of potential barrier height. Moreover, V-I characteristics with temperature dependence are decreased with increasing of $TiO_2mol%$.

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Short Channel GaAs MESFET의 채널전하분포와 채널전하에 의한 전위장벽의 변화 (Potential Barrier Shift Caused by Channel Charge in Short Channel GaAs MESFET)

  • 원창섭;이명수;류세환;한득영;안형근
    • 한국전기전자재료학회논문지
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    • 제19권9호
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    • pp.793-799
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    • 2006
  • In this paper, the gate leakage current is first calculated using the experimental method between gate and drain by opening source electrode. the gate to drain current has been obtained with ground source. The difference between two currents has been tested and proves that the electric field generated by channel charge effect against the image force lowering.

다결정 실리톤의 미세구조와 전기적 특성에 관한 연구 (A study on microstructure and electrical properties of LPCVD polysilicon)

  • 이은구;문대규;정호영
    • E2M - 전기 전자와 첨단 소재
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    • 제5권3호
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    • pp.310-319
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    • 1992
  • LPCVD 방법으로 625.deg.C와 560.deg.에서 증착한 다결정 실리콘에 As이온주입량을 lx$10^{13}$-lx$10^{16}$/$cm^{2}$로 변화시키면서 열처리 전, 후의 미세구조와 전기적 특성 변화를 조사하였다. 625.deg.C에서 증착한 시편은 columnar구조를 하고 있어 표면이 매우 거칠었으며 900.deg.C, 30분 열처리 후에는 As doping 농도에 관계없이 결정립 크기는 200-300.angs.정도였다. 560.deg.C에서 증착한 시편은 비정질 상태로열처리 후에는 1000.angs.이상의 큰 결정립을 갖는 타원형의 결정립으로 성장하였으며 표면이 매우 smooth하였다. 같은 doping 농도에서 전기 전도도와 Hall mobility는 비정질 상태로 증착한 시편이 큰 결정립으로 인하여 다결정 상태로 증착한 시편에 비해 크게 되었다. Grain boundary trapping model에 의해 계산한 potential barrier height는 As doping 농도가 증가함에 따라 감소하였으며 grain boundary trap density는 증착 온도, As doping 농도 및 결정립 크기에 크게 관계없이 3.6~5*$10^{12}$/$cm^{2}$로 측정되었다.

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Doping된 Ⅲ-Ⅴ族 化合物 半導體 界面에서 空間電荷效果 (Space Charge Effects at Doped Ⅲ-Ⅴ Compound Semiconductor Interfaces)

  • 천장호
    • 대한전자공학회논문지
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    • 제27권2호
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    • pp.93-97
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    • 1990
  • 도핑된 半導體 界面의 界面電荷 近似式과 構造를 提案하였다. III-V族 化合物 半導體인 p-GaP,p-InP,n-GaAs와 $C_sNO_3$ 水性 電解質 界面에서 整流現象은 循環電流-電壓特性으로 定性的 解析을 하였다. 半導體 界面의 電流-電壓 特性曲線, 이온 吸着과 電位障壁 過程은 連續循環電壓方法으로 實證하였다. 도핑된 半導體-電解質 界面에서 pn 또는 np 接合構造와 그에 따른 整流形은 空間電荷에 의하여 決定된다.

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Ideal structure for tunneling magnetoresistance and spin injection into semiconductros: Ni(111)/BN/Co(111)

  • Arqum, Hashmi;Son, Jicheol;Hong, Jisang
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2013년도 자성 및 자성재료 국제학술대회
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    • pp.32-32
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    • 2013
  • Using the Vienna ab initio simulation package (VASP) incorporating van der Waals interaction, we have explored structural, adsorption, and magnetic properties of Ni(111)/BN/Co(111) systems. We have found that both Ni(111) and Co(111) layers shows half metallic state, while the spacer BN layer becomes weak metal for one monolayer (ML) thickness and an insulating barrier for two ML thickness. The half metallic states in both Ni(111) and Co(111) layers are robust because it is unchanged independently on the magnetic coupling of Ni(111) and Co(111). This finding suggests that the Ni(111)/BN/Co(111) systems can be utilized for perfect tunneling magnetoresistance system. Moreover, it can be applied for potential spin injecting into semiconductor in FM/semiconductor system due to the fact that the half metallic state in FM layers at the interface will be unchanged.

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Identification of a Deoxyribonuclease I Inhibitor from a Phage-Peptide Library

  • Choi, Suk-Jung;Sperinde, Jeffrey J.;Szoka, Francis C. Jr.
    • Molecules and Cells
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    • 제19권1호
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    • pp.54-59
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    • 2005
  • Deoxyribonuclease I (DNase I) is a divalent cation dependent endonuclease and thought to be a significant barrier to effective gene delivery. The only known DNase I-specific inhibitor is monomeric actin which acts by forming a 1:1 complex with DNase I. Its use, however, is restricted because of tendency to polymerize under certain conditions. We screened two random phage peptide libraries of complexity $10^8$ and $10^9$ for DNase I binders as candidates for DNase I inhibitors. A number of DNase I-binding peptide sequences were identified. When these peptides were expressed as fusion proteins with Escherichia coli maltose binding protein, they inhibited the actin-DNase I interaction ($IC_{50}=0.1-0.7{\mu}M$) and DNA degradation by DNase I ($IC_{50}=0.8-8{\mu}M$). Plasmid protection activity in the presence of DNase I was also observed with the fusion proteins. These peptides have the potential to be a useful adjuvant for gene therapy using naked DNA.

ESTIMATION OF CAKE FORMATION ON MICROFILTRATION MEMBRANE SURFACE USING ZETA POTENTIAL

  • Alayemieka, Erewari;Lee, Seock-Heon;Oh, Jeong-Ik
    • Environmental Engineering Research
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    • 제11권4호
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    • pp.201-207
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    • 2006
  • A simple empirical model with good quantitative prediction of inter-particle and intra-particle distance in a cake layer with respect to ionic strength was developed. The model is an inverse length scale with functions of interaction energy and hydrodynamic factor and it explains that the inter-particle and intra-particle distance in a cake is directly related to the effective size of particles. Particle compressibility with respect to ionic strength was also predicted by the model. The model corroborated very well with experimental results of polystyrene microsphere latex particles microfiltation in a dead end operation. From the results of the model, specific cake resistance could be controlled by the same variables affecting the height of particle energy barrier described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory.

FRT 디자인을 위한 가시적, 비가시적 요인 구축 (Establishment of Visible & Invisible Factors for FRT Design)

  • 한석우
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.1701-1706
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    • 2004
  • FRT design aims at high-tech vehicles of high efficiency and cleanness, it must materialize the meaning and role as new added value by applying car design aesthetics of a new future-oriented concept. In addition, different from ordinary vehicle design, FRT involves invisible factors such as pleasantness, safety, accessibility, controllability, movability, conveniency, culture, identity, brand image and fashionableness. Because FRT vehicles are transportation means used by various groups of people, they must be approached with the barrier-free design concept. Therefore, in order to enhance the potential of future transportation culture emphasizing creativity based on diversity, it is important to establish core design factors that create new added values and to apply new concepts to their roles.

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