• 제목/요약/키워드: charge density

검색결과 1,131건 처리시간 0.024초

ZnS:Cu를 이용한 후막 전계발광소자의 고휘도 특성 (High brightness property of Power Electroluminescent Device using ZnS:Cu)

  • 이종찬;박대희
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권5호
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    • pp.349-353
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    • 1999
  • In this paper, to fabricate the AC power electroluminescent device (PELD) with high brightness, new structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material were BaTiO3 and ZnS:Cu respectively. Fabricated AC power EL devices were estimated by optical and electrical properties of EL spectrum, brightness, CIE coordinate system, transferred charge density and EL emission wave in time domain. With above results, we found that brightness of newly proposed AC powder EL power EL device was 2754 cd/m2 at 100V, 400 Hz and compared with conventional device structure.

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AC-PDP에서 지터와 방전 늦음 시간 개선을 위한 연구 (A study of the Improvement for Jitter and Discharge Delay Time in AC-PDP)

  • 권시옥;김지선;정봉규;황호정
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.506-507
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    • 2005
  • The effects of addition of $D_2$ to conventional gases [Ne-Xe and He-Ne-Xe] on the discharge characteristics were investigated in this work with the aim of improving the voltage margin, the wall charge and the jitter. The addition of an extremely small gas-inlet amounts of $D_2$ increased the number of electrons which improves. the $Xe^*$ density and $Xe_2^*$ density. As a result, the voltage margin, the jitter and the wall charge increased.

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제일원리 LCAO 방법을 이용한 DNA Nucleobase 흡착된 그라핀의 원자 및 전자구조 연구 (A Study on the Atomic and Electronic Structures of DNA-nucleobases-adsorbed Graphene Through First-principles LCAO Method)

  • 이은철
    • 한국전기전자재료학회논문지
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    • 제24권6호
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    • pp.510-514
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    • 2011
  • Based on first-principles LCAO method, we study the electronic and atomic structures of DNA nucleobases adenine (A), thymine (T), guanine (G), and cytosine (C) adsorbed on graphene surfaces. The ${\pi}-{\pi}$ stacking interactions between graphene and nucleobases lead to the bilayer geometries similar to the Bernal stacked graphite. Through the density of states and charge density analyses, it is found that nucleobases are physisorbed on graphene by dispersive interactions with negligible charge exchange. Our calculations reproduce the atomic structures obtained in previous plane wave calculations accurately with much less computation, and well describe the delocalized ${\pi}-{\pi}$ interactions in graphene-nucleobases system, indicating that the LCAO method is very efficient for investigating graphene-bio systems.

고전하밀도 양이온성폴리머와 Sodium dodecyl sulfate가 만드는 콤플렉스에 대한 비이온계면활성제의 영향 (The transformation of the complex of high charge density cationic polymer with sodium dodecyl sulfate into vesicles by nonionic surfactant)

  • 이정노;강계홍
    • 한국응용과학기술학회지
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    • 제25권2호
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    • pp.205-210
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    • 2008
  • The transformation of the liquid crystal complex made by binding of anionic surfactant, sodium dodecyl sulfate (SDS), into high charge density cationic polymer, the homopolymer of diallyldimethylammonium chloride (PDADMAC) was induced by adding of nonionic surfactants and investigated by means of microscopy and FE.SEM. Among nonionic surfactants in this experiments polyethylene glycol (3 mol) ether of lauryl alcohol (laureth-3) made variation in the complex. The laureth-3 transformed the complex into spherulite vesicle with the size of ca.$100{\mu}m$. This change increased the viscosity and the turbidity of the solution phase separated originally. Microscope showed that they are spherulite particles and polarized microscope suggested they are multi.lamellar liquid crystals. FE-SEM also proved that explicitly.

The piezoelectricity of trabecular bone in cancellous bone wave propagation

  • Yoon, Young June;Chung, Jae Pil
    • 한국정보전자통신기술학회논문지
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    • 제14권1호
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    • pp.104-107
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    • 2021
  • The orientation of trabeculae and porosity determine the wave propagation in cancellous bone. Wave propagation, as well as charge density and piezoelectricity, stimulate bone remodeling. Also, Charged ions in the fluid affect wave propagation in cancellous bone. But the trabecular struts' piezoelectricity does not change the waveform of cancellous bone. However, the underlying mechanism is unknown yet why trabecula struts' piezoelectricity does not change wave propagation through cancellous bone. Thus, we derived the governing equation indicating that trabecular struts' piezoelectric properties show that those do not affect wave propagation in cancellous bone.

A Study on Ni-H, Pd-H, and Pt-H Systems by Cluster Orbital Method

  • Lee, Ju-Hyeok;Lee, Keun-Woo;Kim, Ho-Jing
    • Bulletin of the Korean Chemical Society
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    • 제14권2호
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    • pp.225-234
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    • 1993
  • As an application of the cluster orbitals proposed previously, nickel-, palladium-, and platinum-hydrogen systems are studied. Density of states, projected density of states, HOMO levels, and stabilization energies are calculated and compared with those obtained by extended Huckel method for small clusters. These calculations are extended to large clusters to find the size dependence of several physical quantities. Reduced overlap populations are also calculated to clarify the charge transfer phenomena reported earlier. The calculated physical quantities show no dependence on the cluster size. It is also found that the charge transfer occurs due to the intrinsic character of palladium, not due to the edge effect which may be present in small clusters.

초정밀 측정용 정전용량 변위센서에 관한 연구 (A study on a capacitive displacement sensor for the ultraprecision measurement)

  • 안형준;장인배;한동철
    • 한국정밀공학회지
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    • 제14권11호
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    • pp.110-117
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    • 1997
  • This paper discusses numerically and experimenally several design parameters for the plate- type capacitive displacement sensor. The influenences of shape of this sensor on the sensitivity are numerically analyzed with the charge density method. Using many test sensor plates of different shape for verifing the validity of this method can not guarantee the repetibility of experiments. Therefore we made specially the test sensor plate so that experiments of effects of shape of this sensor on sensitivity can be done with only that plate. Results from these experiments agree well with those from numerical analysis.

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Characterization of the Vertical Position of the Trapped Charge in Charge-trap Flash Memory

  • Kim, Seunghyun;Kwon, Dae Woong;Lee, Sang-Ho;Park, Sang-Ku;Kim, Youngmin;Kim, Hyungmin;Kim, Young Goan;Cho, Seongjae;Park, Byung-Gook
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제17권2호
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    • pp.167-173
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    • 2017
  • In this paper, the characterization of the vertical position of trapped charges in the charge-trap flash (CTF) memory is performed in the novel CTF memory cell with gate-all-around structure using technology computer-aided design (TCAD) simulation. In the CTF memories, injected charges are not stored in the conductive poly-crystalline silicon layer in the trapping layer such as silicon nitride. Thus, a reliable technique for exactly locating the trapped charges is required for making up an accurate macro-models for CTF memory cells. When a programming operation is performed initially, the injected charges are trapped near the interface between tunneling oxide and trapping nitride layers. However, as the program voltage gets higher and a larger threshold voltage shift is resulted, additional charges are trapped near the blocking oxide interface. Intrinsic properties of nitride including trap density and effective capture cross-sectional area substantially affect the position of charge centroid. By exactly locating the charge centroid from the charge distribution in programmed cells under various operation conditions, the relation between charge centroid and program operation condition is closely investigated.

유한요소해석을 이용한 전주공정에서의 전류밀도 분포 예측 (Estimate of Current Density Distribution in Electroforming Process Using Finite Element Analysis)

  • 강대철;김헌영;전병희
    • 소성∙가공
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    • 제13권3호
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    • pp.279-284
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    • 2004
  • Electroforming is the highly specialized use of electrodeposition for the manufacture of metal parts and basically a specialized form of electroplating. So, we can apply electrochemical system analysis for electroforming process. Electrochemical systems are concerned with the interplay between electricity and chemistry, namely the measurements of electrical quantities, such as current density, potential, and charge, and their relationship to chemical parameters. This paper based on the basic equations of electrics and electrochemical kinetics, was employed for a theoretical explanation of the current density distribution on electroforming process. We calculated current density distribution and potential distribution on cathode. Also, calculated current density distribution of vertical direction. It was shown that current density is related with distance of between anode and cathode and mass transfer process.

3차원 경계적분방정식법을 이용한 정전장 해석 (Electric Field Analysis Using Three Dimensional Boundary Integral Equation Method)

  • 김재홍;김동훈;박일한
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.828-830
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    • 2000
  • This paper describes BIEM(Boundary Integral Equation Method) for computation of three dimensional electric field distribution and numerical method that an equivalent charge density is unknown variable. After computing numerically the surface charge distribution. the distribution of both potential and electric field are obtained. Finally, this numerical method is applied to the concentric sphere and the coaxial cylindrical model and numerical result is compared to the analytic solution.

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