• 제목/요약/키워드: Electron life time

검색결과 185건 처리시간 0.027초

$TiO_2$ 두께에 따른 염료감응형 태양전지의 전기화학적 임피던스 분석 (Electrochemical Impedance Spectroscopy Analysis on the Dye-sensitized Solar Cell with Different $TiO_2$ thicknesses)

  • 김희제;이정기;서현웅;손민규;김진경;프라바카르;신인영
    • 전기학회논문지
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    • 제58권12호
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    • pp.2425-2430
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    • 2009
  • Dye-sensitized solar cell(DSC) is composed of a dye-adsorbed nanoporous $TiO_2$ layer on fluorine-doped tin oxide(FTO) glass substrate, electrolyte, and platinium doped counter electrode. Among these, a dye-absorbed nanoporous $TiO_2$ layer plays an important role in the performance of the DSC because the injected electrons from excited dye molecules move through this layer. And the condition of $TiO_2$ layer such as the morphology and thickness affects on the electron movement. Therefore, the performances and the efficiency of DSC change as the thickness of $TiO_2$ layer is different. Electrochemical Impedance Spectroscopy(EIS) is the powerful analysis method to study the kinetics of electrochemical and photoelectrochemical processes occurring in the DSC especially the injected electron movements. So we analyzed the DSCs with different $TiO_2$ thicknesses by using EIS to understand the influence of the $TiO_2$ thickness to the performance of the DSC clearly. Finally, we got the EIS analysis on the DSC with different $TiO_2$ thickness from the internal resistance of the DSC, the electron life time and the amount of dye molecules.

Imidazole계 살균제 Prochloraz의 토양 중 잔류량과 반감기분석 (Determination of Residual Concentration and Half-life Time in Soils of Imidazole Fungicide Prochloraz)

  • 최용화;한성수;김일광
    • 분석과학
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    • 제15권1호
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    • pp.67-71
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    • 2002
  • Imidzole계 살균제 prochloraz의 토양(미사질식토) 잔류량 및 반감기를 전자포획검출기를 이용한 기페크로마토그래피로 분석하였다. 토양시료는 acetone/hexane (1:1) 용매로 추출하였고, $LC-NH_2$ Sep-Pak 고체컬럼으로 분리하였다. 표준검정곡선의 감응함수는 0.05~1.00 ng 범위에서 Y = 268.8600X + 0.0664, $R^2=0.9998$ 이었다. 검출한계는 0.02 mg/mL 이었고, 회수율은 0.10 mg/L의 경우 97.3%, 0.40 mg/L의 경우 94.5% 이었다. 반감기는 실내토양에서 24.4일, 포장토양에서 7.6일 이었다.

S/H Life Time에 따른 WSix의 특성 변화에 관한 연구 (A Study on the Characteristics change of WSix Thin Films by S/H Life Time)

  • 정양희;강성준
    • 한국정보통신학회논문지
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    • 제6권5호
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    • pp.689-695
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    • 2002
  • 막질의 조성은 공정 개발과 고품질 생산 적용을 위한 반도체 소자의 제조에 있어서 풍요한 요소의 하나 이다. 막의 표면과 계면의 조성은 기본적으로 AES측 통하여 알 수 있다. 본 연구에서는 온도, DCS post flow, shower head life time 등과 같은 공정조건으로 LPCVD법을 이용한 tungsten suicide 박막을 증착하고 이들의 구조적, 전기적 특성과 조성비를 측정하며 WSix박막을 해석하였고 이로부터 Si/W의 조성비를 비교하였다. Si와 W의 조성비는 DCS post flow에 의하여 WSix박막의 표면에서 증가하였으며, 폴리실리콘과 tungsten silicide 계면에서는 온도의 증가에 따라 조성비가 증가함을 알 수 있었다. 이 결과는 메모리 소자 제조의 WSix 박막 증착의 공정조건 최적화에 적용될 수 있다.

순환여과식 양식 시스템에 있어서의 고정화 탈진균에 의한 질산염 제거 (Nitrate Removal by Immobilized Denitrifying Bacteria in Recirculating Aquaculture System)

  • 김상희;김필균;김중균
    • 생명과학회지
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    • 제9권6호
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    • pp.698-703
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    • 1999
  • For the nitrate removal in recirculating aquaculture system, a denitrifying bacterium, Pseudomonas fluorescens, was isolated from municipal sewage and the cells were immobilized in modified-polyvinly alchol (PVA) gel beads. The immobilized cells in both the fixed-and fluidized-bed reactors showed 98% of denitrification efficiency with 6hr HRT, and the removal efficiency of total organic carbon (TOC) was above 90%. Form scanning electron microscopy (SEM) observation, it was known that biofilm formed in fixed-bed reactor was thicker than that formed in fluidized-bed reactor as operation time passed.

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Note on Drassyllus shaanxiensis of Ground Gnaphosid Spiders (Arachnida: Araneae: Gnaphosidae) in Korea

  • Kim, Byung-Woo;Lee, Won-Cheol;Kwon, Jung-Gyun
    • Animal Systematics, Evolution and Diversity
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    • 제24권1호
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    • pp.33-38
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    • 2008
  • A ground gnaphosid spider, Drassyllus shaanxiensis Platnick and Song, 1986 is reported for the first time in Korea. This species is described with detailed illustrations, leg spination, trichobothrium patterns, and SEM photographs of male palpal organ and female epigynum.

Novel Host materials for Phosphorescent OLEDs with long lifetime

  • Kim, Young-Hoon;Yu, Eun-Sun;Kim, Nam-Soo;Jung, Sung-Hyun;Kim, Hyung-Sun;Lee, Ho-Jae;Kang, Eui-Su;Chae, Mi-Young;Chang, Tu-Won
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.549-552
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    • 2008
  • We have developed a novel bipolar host material with both electron and hole transporting characteristics. Since CGH(Cheil Green Host) has some electron transporting characteristics, it shows increased luminance efficiency in device including TCTA and without HBL(hole blocking layer:BAlq). Maximum power efficency of CGH was 27.4lm/W at the device structure ITO/DNTPD(60)/NPB(20)/TCTA(10)/EML(30)/Alq3(20)/LIF(1)/Al. We measured device performance again without HBL. The result of CGH showing 26.0lm/W is outstanding compared to that of CBP showing 19.1lm/W without holeblocking layer. We also measured lifetime and found to be 205hr at 3000nit, that is significant result compared to the life time of CBP device showing 82hr. CGH shows high device performance with holeblocking layer. Moreover, it shows better device performance and life time than those of CBP without holeblocking.

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Novel Organic Electron Injectors for the Enhancement of Lifetime, Efficiency and Reduction in Operating Voltage in OLEDs

  • Kathirgamanathan, Poopathy;Arkley, Vincent;Surendrakumar, S.;Paramaswara, G.;Ganeshamurugan, S.;Antipan-Lara, J.;Ravichandran, S.;Kumaraverl, M.;Chan, Y.F.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1206-1209
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    • 2007
  • Both PM-OLEDs and AM-OLEDs are now in production. However, manufacturers are still concerned about life-time, voltage drift, operating voltage and efficiency in order to develop larger displays. Most material suppliers seem to be focussing on emitters and the benefits of introducing suitable charge transporters have been largely unexplored. OLED-T has developed a novel organic electron injector (Trade Name: EI-101) which evaporates at a very low temperature of $300^{\circ}C$ as opposed to the conventional LiF which requires $580^{\circ}C$. EI-101 has been found to increase the lifetime by up to 12%, reduce the voltage drift by up to 61% and increase the efficiency by up to 15%. The material can be handled in air and in situ Q-mass spectroscopy on extended thermal evaporation has confirmed its high stability for use in mass production.

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옥수수의 파종시기 및 질소수준별 광화학적 반응 해석 (Photochemical Response Analysis on Different Seeding Date and Nitrogen (N) level for Maize (Zea mays L.))

  • 박소현;유성영;이민주;박종용;송기태;김태완;이병무
    • 한국작물학회지
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    • 제60권1호
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    • pp.1-7
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    • 2015
  • 본 연구는 파종시기와 질소시비 수준에 대한 옥수수의 광화학적 반응을 분석하여 광생리적 특성을 해석하였다. 1. 5월 22일 파종시 질소 함량이 증가함에 따라 생육후기까지 엽록소 형광량 또한 증가하여 질소 배량처리에서 광이용효율이 더 높은 것으로 확인되었다. 2. 생육초기의 형광량이 가장 높았으며, 이후 모든 처리구에서 엽록소 형광량이 50% 가량 감소하여 전자전달을 위한 광화학 반응이 크게 감소했음을 알 수 있었다. 3. 질소 반량구에서 활성화된 RC (RC/ABS)가 감소하며 13% 이상의 에너지가 손실되었으며, 결국 전자전달시 에너지 전환효율(PI, DF 등)이 감소해 광이용효율이 낮았다. 4. 배량 처리구는 생육후기로 갈수록 전자전달 효율(ET2o/CS) 및 단면당 활성화된 RC(RC/CS) 등 광이용 효율이 대조구 대비 크게 증가하여 광합성기구 사이의 전자전달이 잘 이루어지는 것으로 확인되었다.

장시간 사용된 가스터빈 블레이드의 저주기피로 손상도 평가 (Evaluation of Low Cycle Fatigue Damage of Gas Turbine Blades Used for a Long Time)

  • 허인강;김재훈
    • 한국안전학회지
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    • 제33권3호
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    • pp.8-14
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    • 2018
  • Ni-base superalloy has excellent resistance to extreme environments such as high temperatures and high stresses and are used as materials for large gas turbines. In this paper, the specimens were taken from the blade that were used for a long time, and their life span was studied by microstructure analysis and avoidance of cursing. The microstructural analysis of the specimens was carried out using a OM and SEM to observe the coarsening, carbides on gamma prime. Low-cycle fatigue tests were performed on new material and airfoil of long time-used blade. The test was conducted under various deformation conditions and temperature conditions of $760^{\circ}C$ and $870^{\circ}C$. The low cycle fatigue test was carried out using the Coffin-Manson equation and the fatigue life was predicted. After the test, crack path and fracture surface were analyzed using SEM.

Morphology and distribution of some marine diatoms, family Rhizosoleniaceae, genus Rhizosolenia, in Korean coastal waters

  • Yun, Suk-Min;Lee, Sang-Deuk;Lee, Jin-Hwan
    • ALGAE
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    • 제26권2호
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    • pp.141-152
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    • 2011
  • The present study describes the morphology, taxonomy, and distribution of species belonging to the diatom genus Rhizosolenia in Korea's marine coastal waters. From September 2008 to February 2010, we collected phytoplankton samples at 30 sites along the Korean coastline and studied them by light and scanning electron microscopy. We found 6 rhizosolenid genera in our samples: Rhizosolenia, Dactyliosolen, Guinardia, Pseudosolenia, Proboscia, and Neocalyptrella. In the present paper, we studied the following rhizosolenid species and compared them with congeners: R. pungens, R. fallax, R. imbricata, Rhizosolenia sp. 1, and Rhizosolenia sp. 2. The morphology of R. pungens exhibits important diagnostic characteristics in its girdle segment structure in the column and in its external process. To distinguish R. fallax and R. imbricata, the most important characteristics are the striation and the velum structure. R. pungens occurred in our samples all along the Korean coast. Only rarely did we find R. imbricata in the samples and at low abundance. We recorded R. fallax, Rhizosolenia sp. 1 and Rhizosolenia sp. 2 for the first time in Korean waters, but they rarely occurred.