• Title/Summary/Keyword: Conducting

Search Result 7,166, Processing Time 0.038 seconds

Nanocarbon/silver Nanowire Hybrid Flexible Transparent Conducting Film Technology (탄소나노튜브와 은나노와이어 복합 유연투명전극 필름 기술)

  • Han, Joong Tark
    • Journal of the Korean institute of surface engineering
    • /
    • v.49 no.4
    • /
    • pp.323-330
    • /
    • 2016
  • The flexible transparent conducting films (TCFs) are required to realize flexible optoelectronic devices. 1D nanomaterials such as carbon nanotubes (CNTs), metal nanowires are good candidates to replace indium tin oxide that is currently used to fabricate transparent electrode. Particularly, silver nanowires are used to produce flexible TCFs. In this review, we introduce TCF technologies based on silver nanowires/CNTs hybrid structures. CNTs can compromise drawbacks of silver nanowires for applications in high performance TCFs for optoelectronic devices.

Conducting Polypyrrole Doped with Hexacyanoferrate Anions: an Electrochemical and Spectroscopic Study

  • Han Junghee;Lee Seungjun;Paik Woon-kie
    • Bulletin of the Korean Chemical Society
    • /
    • v.13 no.4
    • /
    • pp.419-425
    • /
    • 1992
  • Conducting polypyrrole doped with iron (Ⅱ,Ⅲ) hexacyanate Fe$(CN)_6^{z-}$ ions was studied for its physical and electrochemical properties. The polymer exhibited two pairs of waves in the cyclic voltammogram, one for the reversible oxidation/reduction of the incorporated iron hexacyanate ions and the other for the near-reversible oxidation/reduction of the polypyrrole moiety. The exchange of ions incorporated in the polymer and other ions present in solutions were examined by following the decrease of the reversible redox peaks of Fe$(CN)_6^{z-}$, and by EDX analysis. The spin density of this highly conducting polymer as probed by ESR spectroscopy was extremely low compared to polypyrrole doped with common anions.

Solid oxide fuel cell and application of proton conducting ceramics (고체산화물 연료전지와 양성자 전도성 세라믹 물질의 응용)

  • Jeong, Donghwi;Kim, Guntae
    • Ceramist
    • /
    • v.21 no.4
    • /
    • pp.366-377
    • /
    • 2018
  • Solid oxide fuel cells (SOFCs) are promising eco-friendly energy conversion system due to their high efficiency, low pollutant emission and fuel flexibility. High operating temperatures, however, leads to the crucial drawbacks such as incompatibility between the components and high thermal stress. Proton-conducting ceramic fuel cells (PCFCs) with proton-conducting oxide (PCO) materials are new types of fuel cells that can solve the problems of conventional SOFCs. Many studies have been proceeded to improve the performance of electrolytes and electrodes, and triple conductive oxides (TCOs) have attracted significant attention as high performance PCFC electrodes.

Effect of Horizontal Conducting Walls and Partitions on Two-Dimensional Laminar Natural Convective Heat Transfer in a Rectangular Enclosure (수평전도벽과 간막이가 직4각형 밀폐공간내에서의 2차원 층류 자연대류에 미치는 영향)

  • Lee Taik Sik;Lee Sang Woo
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.16 no.2
    • /
    • pp.204-215
    • /
    • 1987
  • Laminar natural convective heat transfer within a two-dimensional rectangular enclosure with horizontal conducting walls and partitions was investigated by numerical analysis and experiment. The enclosure consists of two isothermal vertical walls and two adiabatic horizontal walls. This combined heat transfer problem of conduction and natural convection was solved using finite difference method with SIMPLE algorithm, and temperature distribu-tions in the air filled enclosure was obtained using Mach-Zehnder interferometer. Good agree-ment was obtained between the predicted and measured results. The effect of geometric parameters and thermal properties on heat transfer was studied far Grashof numbers in range, $1\times10^4\;{\leqslant}\;G^r\;{\leqslant}\;6.4\times10^5.$ It was found that both velocity and temperature fields were in-fluenced significantly by thermal conductivity of the conducting walls and the partitions, and by geometry of partitions.

  • PDF

The Application and Electrical, Optical Properties of $In_2O_3$: Sn Transparent Conducting Films (ITO투명도전막의 전기, 광학적 특성 및 그 응용)

  • Lee, Dong Hoon;Park, Ki Cheol;Park, Chang Bae;Kim, Ki Wan
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.23 no.4
    • /
    • pp.498-505
    • /
    • 1986
  • In2O3: Sn(ITO) transparent conducting films were fabricated by the electron beam evaporation method. The dependence of their electrical and optical properties on deposition conditions were examined. The optimum evaporation conditions were such that the deposition rate was 5-10\ulcornersec, oxygen partial pressure was 4x10**_4 torr, substate temperatudre was above 300\ulcorner, and SnO2 doping rate was 10 mol%. The values of sheet resistance and transmittance of the films in visible region fabricated under these optimum conditins were 12\ulcorner/ and 87-99%, respecively. And the energy conversion efficiency of the SIS solar cell fabricated using ITO was 9.16%. It is shown that the transparent conducting films can be applied to the TV camear pick-up tube and solar cell.

  • PDF

Analytical model for the formation of electric fields in parallel-plate capacitors

  • Taehun Jang;Jungmin Moon;Hye Jin Ha;Sang Ho Sohn
    • Journal of Science Education
    • /
    • v.46 no.2
    • /
    • pp.212-221
    • /
    • 2022
  • In this study, we propose an analytical model to elucidate the formation of electric fields between two parallel conducting plates. Using nine Gaussian surfaces, we investigated the charge redistributions and electric fields formed by parallel conducting plates when two charged plates get close together. The electric charges are redistributed via a new electrostatic equilibrium to create the electric field of each plates. As a result, the electric field start from + electrode plate to - electrode plate via inducing a new electrostatic equilibrium, implying that the application of Gaussian surfaces to only one of the electrodes of parallel-plate capacitors is deserved. The results will help undergraduate students understand the charge redistribution and the electric field formation in parallel-plate capacitors in a reasonable manner.

A Qualitative Study of Running질 Science Garden질 (과학동산 운영에 관한 질적 연구)

  • 채동현;이수영
    • Journal of Korean Elementary Science Education
    • /
    • v.21 no.2
    • /
    • pp.263-288
    • /
    • 2002
  • 'Science Garden' is a science program that develops acquirements of science & technology at an early stage through experiential study and inspire the spirit of scientific inquiry by carrying out laboratory work, science movie, science lecture, scientific work, outdoor activities, computer classes and science experiment which is hard to do through the regular educational course. It is targeted grade 4,5,6 students during summer and winter vacation. 'Science Garden' is conducted by selective participation freely. It is a wholelistic activity that develops children's potential talents or creativities, improves interest and attitude toward science, and also gives opportunity for self-realization by extending capacity for inquiry to show each student's ability. This study is observed and is compared how it is conducted in elementary school using qualitative study. This study is used narrative observation, in-depth interview and document analysis. Objects of narrative observation are two elementary schools, each from Jellabukdo and Gyeonggido, and 7 teachers were interviewed in-depthly. Here are results of the study. 1 A teacher in school G never takes part in student activities, tends to be indifferent to classes, but focuses on observation and experiment in laboratory. And feedback or evaluation about student's activity is never done. On the other hand, a teacher in school S guides students to understand the principals of science on themselves, and wide variety forms of activities such as role playing, discussion, and games are being done. But an effort to evaluate student's activity is not being made properly. 2. Teachers set a high valuation on the need of 'Science Garden'. Observing the way of conducting 'Science Garden', usually teachers who is in charge of science for official work is selected as a teacher in charge, and groan under a heavy burden of conducting it without anyone's help. Participating students are selected by volunteering or teacher's recommendation, but because of low Participation rate, teachers have difficulty in conducting it. Plan for conducting ‘science Garden’ is made 20 days before it, after getting an official document from Office of Education, refering to booklets produced by National Jungang Science Institute, or data from Office of Education, and internet. Teachers evaluate rarely Most school principals have interest in 'Science Garden' but parents are not well aware of it, The budget is made at the same time with the plan, and scale is varied between 200,000∼500,000 won. Because of the improper way of selecting teacher in charge, difficulty in selecting students, heavy works caused by planning, conducting the program, as well as reporting teacher's work, and lack of parents' awareness, 'Science Garden' has been conducted formally and superficially. Next gives you direction to change, for the right way of conducting' Science Garden'. It is important to motivate competent teachers to instruct students actively. For students' active participation, They should publicize thoroughly beforehand, and develope 'Science Garden' program for teachers to be able to make better use of it. Evaluation of student activities and program should be done in the aspect of developing students’ faculties. Beside of school facilities, they need to put diverse local facilities and places to practical use for immediate natural experience. And not only separate schools but also associated form of schools to conduct it is necessary.

  • PDF

A study on the functional application of conducting polymer (도전성 고분자의 기능성 응용에 관한 연구)

  • 김종욱;김현철;정인성;김현관;구할본;김태성
    • Electrical & Electronic Materials
    • /
    • v.7 no.6
    • /
    • pp.520-526
    • /
    • 1994
  • A rectifying heterojunction consisting of polyparaphenylene(PPP) and polypyrrole(PPY) films was prepared by the electrochemical method. The photoresponse in the heterojunction of PPY and PPP is similar to the absorption spectrum of undoped PPP. This fact suggests that photoresponse depends strongly upon polyparaphenylene of semiconductor. The fill-factor was calculated from the photo current-voltage curve to be 0.19, which is relatively small compared to polyacetylene-polythiophene heterojunctions.

  • PDF

Evaluation of Prediction Methods for Containment Integrated Leakage Rate (격납건물 종합누설률 예측방법 평가)

  • Yang, Seung-Ok;Lee, Kwang-Dae;Oh, Eung-Se
    • Proceedings of the KIEE Conference
    • /
    • 2004.11c
    • /
    • pp.562-564
    • /
    • 2004
  • The containment leakage rate test performed on the nuclear power plants consists of following phases : pressurizing the containment, stabilizing the atmosphere, conducting a Type A test, conducting a verification test, depressurizing the containment. It takes more than 48 hours from the pressurization to the depressurization and the prediction of the results will help to prepare the next test phase. In this paper, to predict the leakage rate, the prediction methods based on the least square method are evaluated according to the input variables and the measurement period.

  • PDF