• 제목/요약/키워드: Ionization efficiency

검색결과 105건 처리시간 0.027초

물-수증기 계면을 통한 전기방전에 의한 수소 제조 (Hydrogen Generation by Electrical Discharge across Water-Vapor Interface)

  • 강구진;이수창;최용만;이웅무
    • 한국수소및신에너지학회논문집
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    • 제8권4호
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    • pp.155-160
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    • 1997
  • Generation of hydrogen and oxygen gas from water is mostly accomplished by electrolysis. In this report, a scheme is presented regarding the gas generation based on plasmolysis. Unlike electrolysis water dissociation by electrical discharge (plasmolysis) requires a high voltage to cause either electron emission or electron capture, and subsequent ionization of involved molecular species. When electrical discharge is initiated between electrodes separated by water-vapor interface, a very large electric field(~100kV/cm) is developed at the tip of the electrode placed in the vapor phase. It is found that the efficiency of plasmolysis depends on the polarity of the electrode placed in the vapor phase. Also presented is the scheme of hydrogen and oxygen generation by such electrical discharge.

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Sn-complexes를 이용한 OLED의 발광 특성 향상에 관한 연구 (Improvement of Luminance Properties of Blue OLEO using $SnDP(HPB)_2$)

  • 김동은;최규채;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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    • pp.121-122
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    • 2008
  • Blue emitting materials have been explored by various researchers. However, blue-emitting materials with high luminous efficiency, good color purity, and thermal stability are still much desired. In this study, we synthesized a new blue luminescent material, $SnDP(HPB)_2$ which is low molecular compound and thermal stability. The PL spectrum of $SnDP(HPB)_2$ was observed blue at the wavelength of 447nm. The ionization potential(IP) and the electron affinity(EA) of $SnDP(HPB)_2$ was measured to be 6.7 eV and 3.0 eV, respectively. The fundamental structure of the OLED was ITO/NPB/$SnDP(HPB)_2/Alq_3$/LiF/Al. As a Result, we obtained to enhance the performance of blue OLED.

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The Evaluation of Solid-Phase Microextraction(SPME) Techniques for Analyzing Mixed Fuel Oxygenates and Products

  • 이재선;이시진;장순웅
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 추계학술발표회
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    • pp.458-461
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    • 2003
  • Solid-phase microextraction (SPME) and gas chromatography/headspace techniques(HS) and flame ionization detection (GC/FID) have been combined for determination of very polar compounds in water, including the widely used gasoline oxygenates and by-products. A relatively simple extraction method using a CAR/PDMS(75${\mu}{\textrm}{m}$) SPME fiber was optimized for the routine analysis of gasoline oxygenates and by-products in groundwater and reagent water. A sodium chloride concentration of 25%(w/w) combined with an extraction time of 20 min provided the greatest sensitivity while maintaining analytical efficiency Replicate analyses in fortified reagent and groundwater spiked with microgram per liter concentrations of gasoline oxygenates and by-products indicate quantitative and reproducible recovery of these and related oxygenate compounds. Method dynamic range was 50$\mu\textrm{g}$ L-1 to 3000$\mu\textrm{g}$ L-1 for gasoline oxygenates and by-products.

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Development of a Four-way Interface for Online Capillary Isoelectric Focusing-Electrospray-Mass Spectrometry (CIEF-ESI-MS)

  • Yu, Hai Dong;Kim, Byungjoo;Shin, Dae-Ho;Ahn, Seonghee
    • Mass Spectrometry Letters
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    • 제4권4호
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    • pp.83-86
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    • 2013
  • A new interface for coupling CIEF and MS using a four-way cross has been developed in a single mechanical system. This new interface could be operated without the electric discontinuity and reinstallation of lines. Additionally, a bare fused silica capillary was facilitated as a spray needle to produce electrospray and to guide catholyte or sheath liquid. Focusing for CIEF was completed in a hanging droplet at the end of spray needle. This capillary spray needle also provided stable spray, enhanced the ionization efficiency and increased sensitivity. Results with carbonic anhydrase I showed that focusing and spraying were well completed with the new interface and the new spray needle.

세그먼트 아크히터 내부에서 공기와 아르곤 기체의 혼합 현상에 대한 연구 (Investigation of Separated Injection of Air and Argon in Segmented Constrictor Type Arc Heaters)

  • 이정일;정가람;김규홍
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.197-200
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    • 2008
  • The existing computer code to solve the air flow in a segmented constrictor-type arc-heated wind tunnel named ARCFLO4 is improved to accept an air-argon mixture as the working gas and to consider the separated injection of air and argon. The new version of the code is used to calculate the flows in the Aerodynamic Heating Facility of NASA Ames Research Center where argon concentration is relatively high. The calculation shows that argon tends to increase the diameter of the arc-column, increase ionization fraction, decrease thermal efficiency of the arc-heater, and push the ratio of the centerline-to-average enthalpy toward unity. The calculated operating characteristics of the arc-heater agree well with the experimental data.

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CSP용 시소타입 로딩장치의 개발 (Development of Seesaw-Type CSP Solder Ball Loader)

  • 이준환;구흥모;우영환;이종원;신영의
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.873-878
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    • 2000
  • Semiconductor packaging technology is changed rapidly according to the trends of the micro miniaturization of multimedia and information equipment. For I/O limitation and fine pitch limitation, DIP and SOP/QFP are replaced by BGA/CSP. This is one of the surface mount technology(SMT). Solder ball is bumped n the die pad and connected onto mounting board. In ball bump formation, vacuum suction type ball alignment process is widely used, However this type has some problems such as ionization, static electricity and difficulty of fifo(first-input first-out) of solder balls. Seesaw type is reducing these problems and has a structural simplicity and economic efficiency. Ball cartridge velocity and ball aligned plate angle are Important variables to improve the ball alignment Process. In this paper, seesaw-type CSP solder ball loader is developed and the optimal velocity and plate angle are proposed.

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에너지 준위 접합 최적화를 통한 유기태양전지 효율 향상법 (Optimization of energy level alignment for efficient organic photovoltaics)

  • 이현복
    • 진공이야기
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    • 제2권2호
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    • pp.12-16
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    • 2015
  • Organic photovoltaics (OPVs) have attracted significant interest in an interdisciplinary research field for the decades as a next-generation photovoltaic device due to their unique advantages. One of requirements for OPVs having high power conversion efficiency is the favorable energy level alignment between the electrode/organic and organic/organic interfaces to manage the exciton dissociation and improve the charge transport. In this review, strategies to enhance the OPV performance by controlling the energy level alignment are discussed. The insertion of an exciton blocking layer leads to the efficient dissociation of photogenerated excitons at the donor/acceptor interface enhancing the short-circuit current density. The choice of a donor having a high ionization energy and an acceptor having a low electron affinity increases the open-circuit voltage. The insertion of an appropriate work function modifier which reduces the charge injection barrier removes the S-kink in current density-voltage characteristics of OPVs and improves the fill factor. This review would give a valuable guide to design the efficient OPV structure.

New electron source and electron collection source for the internal electron circuit in FL tubes

  • Ozawa, Lyuji;Tian, Yakui;Kato, Masatoshi
    • Journal of Information Display
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    • 제12권2호
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    • pp.69-75
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    • 2011
  • A new electron source and an electron collection source were found for the closure of the internal electron circuit inside fluorescent lamp (FL) tubes. The sources are formed in front of the polarized electric-insulator particles on the metal electrodes at both ends of the FL tube. The appearance and disappearance of both sources are controlled by the electric voltages applied to the metal electrodes. The electrons and $Ar^+$ for the sources are generated by the ionization of the Ar atoms, and they return to the Ar atoms at the electron collection source. Thus, the Ar atoms are preserved in the FL tubes, ensuring a long operation life for such tubes.

유도결합형 플라즈마에서의 Ne, Ar, Kr 혼합가스 방전특성 (Inductively Coupled Plasma discharge characteristic of Ne, Ar, Kr mixed gas)

  • 허인성;최용성;이종찬;박대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.306-309
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    • 2004
  • Recently, the environmental problem has received considerable attention. so, many lamps have been developing for environmental requirement and energy efficiency. also, at glow discharge lamp researchers try to reduce energy spending that is power saving lamp. this kind requirement agree with strong points of electrodeless fluorescent lamp has received to now lighting sauce. At low pressure as mTorr I.C.P make high density plasma easily, is good to maintain discharge, has high ionization and does not have failing lighting and losing ability of electron radiation by oxidation and volatilization of electrodes, because this tape does not have electrodes. This point of I.C.P can use at electrodeless fluorescent lamp in this study ICP display elements and Ar, Ne, Kr are researched for optical characteristic. each gas is looked into optical characteristic, also mixed gases is experiment for optical characteristic.

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Solving Time-dependent Schrödinger Equation Using Gaussian Wave Packet Dynamics

  • Lee, Min-Ho;Byun, Chang Woo;Choi, Nark Nyul;Kim, Dae-Soung
    • Journal of the Korean Physical Society
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    • 제73권9호
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    • pp.1269-1278
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    • 2018
  • Using the thawed Gaussian wave packets [E. J. Heller, J. Chem. Phys. 62, 1544 (1975)] and the adaptive reinitialization technique employing the frame operator [L. M. Andersson et al., J. Phys. A: Math. Gen. 35, 7787 (2002)], a trajectory-based Gaussian wave packet method is introduced that can be applied to scattering and time-dependent problems. This method does not require either the numerical multidimensional integrals for potential operators or the inversion of nearly-singular matrices representing the overlap of overcomplete Gaussian basis functions. We demonstrate a possibility that the method can be a promising candidate for the time-dependent $Schr{\ddot{o}}dinger$ equation solver by applying to tunneling, high-order harmonic generation, and above-threshold ionization problems in one-dimensional model systems. Although the efficiency of the method is confirmed in one-dimensional systems, it can be easily extended to higher dimensional systems.