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TiO2와 Graphene 혼합물을 전극으로 사용한 염료감응형 태양전지특성 연구 (Dye-Sensitized Solar Cell Based on TiO2-Graphene Composite Electrodes)

  • 바트무르;양우승;암바데;이수형
    • Korean Chemical Engineering Research
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    • 제50권1호
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    • pp.177-181
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    • 2012
  • 본 연구에서는 $TiO_2$ 필름에 그라핀나노시트(graphenenanosheet, GNS)의 양을 다르게 함으로써 형성한 전극을 이용하여 염료감응형 태양전지를 제작하였고 그 특성을 연구하였다. $TiO_2$-GNS 혼합물 전극은 단순한 혼합방식에 의하여 제작되었으며, N3를 염료로 사용하여 태양전지의 효율을 평가하였다. $TiO_2$-GNS 혼합물 전극을 사용한 염료감응형 태양전지의 전환효율은 GNS의 양에 의해 영향을 받았으며, $TiO_2$에 GNS를 0.01 wt% 혼합한 전극을 사용하여 제작한 염료감응형 태양전지가 가장 높은 효율인 5.73%를 나타내었다. 이는 GNS를 혼합하지 않은 전극을 사용한 태양전지보다 26% 높은 효율이었다. 이와 같은 효율 증가의 원인으로는 GNS 첨가에 의한 N3의 흡착량 증가, 전자 재결합(electron recombination)과 back transport reaction의 감소, 전자 수송의 증가로부터 기인한 것으로 생각된다. 본 연구에서 $TiO_2$(anatase)와 GNS의 존재는 Field-Emission Scanning Electron Microscopy를 통하여 확인하였으며, 흡착된 염료의 양은 자외선분광기(UV-vis Spectroscopy), 전자 재결합의 감소 및 전자 수송에 대한 분석은 전기화학적 임피던스분광법(Electrochemical Impedance Spectroscopy)을 이용하였다.

AlN 단결정 성장에 관한 도가니 형태의 의존성에 관한 연구 (A study on the dependance of crucible dimension on AlN single crystal growth)

  • 인경필;강승민
    • 한국결정성장학회지
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    • 제25권1호
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    • pp.1-5
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    • 2015
  • AlN 단결정의 특별한 용도로 이를 개발하기 위한 노력이 전 세계적으로 매우 활발하게 이루어지고 있다. 이러한 AlN을 기반으로 하는 자외선 LED는 생활, 의학, 자동자 등에 유용한 용도로서 살균, 정화, 경화 및 분석 등 분야에 이용된다. 이에 실험을 통해 PVT법으로 카본 도가니를 사용하여 AlN 단결정을 성장시켰으며 실험 중 3가지 형태의 도가니를 이용하여 성장에 미치는 영향을 분석하였으며, 그 온도 조건은 $1900{\sim}2100^{\circ}C$이고 실험 압력으로는 1~200 Torr였다. 그 결과, 높이가 높은 형태의 도가니를 사용할 경우 증발량은 기준 형태보다 증가 하는데 그쳤다. 반면, 넓은 형태의 도가니는 더욱 많은 증발양의 증가를 보였으며, 기준 형태에 비하여 훨씬 안정하다는 것을 알았다. 또한, 제한된 크기의 도가니를 이용한 PVT법에서의 도가니 형태의 변화에 따른 결과는 성장률에 따른 최적 조건, 성장 결정의 품질변화 및 성장 조건 안정성에 영향을 주는 것을 알았다.

버퍼층으로서 플라즈마 polythiopheneol 유기EL소자에 미치는 영향 (Effect of plasma polythiophene as a buffer layer inserted on OLEDs)

  • 박상무;이붕주;김형권;임경범;김종택;박수홍;임응춘;이은학;이덕출
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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    • pp.177-180
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    • 2002
  • The purpose of this thesis is to develope buffer materials by the plasma polymerization method. In this article the buffer materials, plasma poly thiophene(PPTh) is used to study the interface of eter/organic in organic light emitting diodes(OLED). The interface of meter/organic materials is the important and critical objectives in development of OLED. The hole transport layer was N,N'-dipheneyl-N, N'bis-(3-methypheneyl)-1,1'dipheneyl-4,4'-diamine (TPD); the host material of mission layer was 8-tris-hydroxyquinoline aluminium (Alq3). When PPTh was inserted between ITO and TPD, emission efficiency increased.

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AlGaN/InGaN HEMTs의 고성능 초고주파 전류 특성 (DC and RF Characteristics of AlGaN/InGaN HEMTs Grown by Plasma-Assisted MBE)

  • 이종욱
    • 한국전자파학회논문지
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    • 제15권8호
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    • pp.752-758
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    • 2004
  • 본 논문에서는 MBE로 성장한 AlGaN/InGaN/GaN 에피층으로 제작된 GaN HEMTs의 특성을 분석하였다. 게이트 전극 길이가 0.5 $\mu$m로 제작된 소자는 비교적 평탄한 전류 전달 특성을 나타내었으며 최대 전류 880 mA/mm, 최대 전달정수 156 mS/mm, 그리고 $f_{r}$$f_{MAX}$는 각각 17.3 GHz와 28.7 GHz가 측정되었다. 또한 표면 처리되지 않은 AlGaN/InGaN/HEMT의 경우 기존의 AlGaN/GaN HEMT와는 달리 펄스 전류 동작 상태에서 전류 와해 현상(current collapse)이 발생하지 않음이 확인되었다. 이 연구 결과는 InGaN를 채널층으로 사용할 경우 표면에 존재하는 트랩에 의한 전류 와해 현상이 발생하지 않는 고성능, 고출력의 GaN HEMT를 제작할 수 있음을 보여준다....

대화중음(大和中飮)의 효능(效能)에 관(關)한 실험적(實驗的) 연구(硏究) (A Experimental Study on the effects of DAEWHAJUNGEUM)

  • 양수미;유봉하;박동원;유기원
    • 대한한의학회지
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    • 제18권2호
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    • pp.82-96
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    • 1997
  • In order to investigate the effect of Daewhajungeum on the isolated organs, gastrointestinal tract and C.N.S., some kinds of experiments using mice and rats were done. The results were as follows; 1. Daewhajungeum showed the inhibitory effect on the smooth muscle contraction of the isolated ileum and colon induced by acethylchorine chloride and barium chloride in mice. 2. Daewhajungeum showed inhibitory effect on the contraction of the fundus-strip induced by acethylchorine chloride and barium chloride in rats. 3. The preventive effect on pyloric ulcer, indomethacin induced ulcer and ethanol-HCl induced ulcer of mice was recognized. 4. The effect on the acidity of gastric juice was suppressed, but the effect on the pepsin output was not recognized. 5. The transport ability of small and large intestine was significantly decressed. 6. The analgesic effect and the sedative effect were recognized so that the effect of the C.N.S was suggested.

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GIS와 연동된 2차원 퇴적물이동 모델링 (Coupling of GIS and time dependent 2-D Sediment Transport Modeling)

  • Lim, Hak-Soo;Kim, Chang S.;Lee, Sue-Hyun;Yoo, Dong-Hoon
    • 한국해안해양공학회:학술대회논문집
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    • 한국해안해양공학회 2002년도 한국해안해양공학발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
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    • pp.208-211
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    • 2002
  • The Kyunggi Bay (125-l28E, 36-38N) is a macro-tidal bay in the western central port of Korean Peninsula(Fig. 1). The Bay characterizes its feature as wide tidal flats, deep tidal channels and tidal sand ridges running in parallel to tidal flows. The macro-tidal range (up to approximately 8.6m) and consequent strong tidal currents erode the bottom sediment and selectively transport to the low-energy area forming tidal ridges or tidal flats. (omitted)

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성장호르몬방출펩타이드-6 (GHRP-6)의 경피투과 (Iontophoretic Transport of GHRP-6)

  • 최보경;오승열
    • Journal of Pharmaceutical Investigation
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    • 제31권4호
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    • pp.273-279
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    • 2001
  • The purpose of this study is to characterize the iontophoretic transport of growth hormone releasing peptides (GHRP-6) through hairless mouse skin from aqueous solution. The effect of various factors, such as pH, poloarity, current profile, current density, current duration, ionic strength, drug concentration, and enhancer application was studied to obtain basic knowledge on the transport. We have also studied the stability of GHRP-6 in solution with/without current. The donor chamber was filled with phosphate buffer solution containing GHRP-6 and the receptor chamber was filled with phosphate buffer solution (pH 7.4). Ag/AgCl electrode was used for their stability and reversibility. At a predetermined time interval, sampling was made and the concentration of drug was analysed using HPLC system. The results showed that, compared to passive flux, the total amount of drug transported increased markedly by the application of anodal current. Cathodal flux was similar to passive flux. Flux increased with the current density, the duration of current application and drug concentration. The effect of enhancers on the flux was studied using hydrophilic (5% N-methyl pyrrolidone) and hydrophobic (5% propylene glycol monolaurate, 5% oleic acid) enhancers. Application of enhancer also increased the flux.

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Gender Differences in Influence of Socio-demographic Characteristics on Mode Choice in India

  • SAIGAL, Taru;VAISH, Arun Kr.;RAO, N.V.M.
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.531-542
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    • 2021
  • The study aims to investigate differences between men and women in influence of various socio-demographic factors on choice of mode of transport. For this purpose, a binary logit model of choice probabilities is implemented on survey data of a developing country city. Results indicate women's choice of travel mode to be more environment-friendly than that of men. Well-educated, working and middle-aged individuals appear to be the most likely to choosing more-polluting modes of transport for frequent travelling purposes. Individuals in the sample who are the least socioeconomically well off are found the most likely to be promising for the environment. The findings of this study suggest the future transportation policies toward development of existing infrastructure of greener modes of transportation in the city such as, public transportation services and pedestrian lanes, so as to manage the rising issues of degrading environmental quality. The study highlights how the consideration and inclusion of socio-demographic factors is crucial for policy recommendation regarding curtailing the environmental damages contributed by transportation sector. Because mobility crucially affects all other indicators of empowerment, and women are the ones using green modes extensively, the city's transportation system should be so developed which gives their safety and security due importance.