• 제목/요약/키워드: crystal cells

검색결과 467건 처리시간 0.026초

셀갭 변화에 따른 Flexible 기판 TN-LCD의 전기광학특성 (Electro-Optical Performances of Flexible Liquid Crystal Display on Twisted Nematic Mode according to Cell Gap)

  • 강희진;황정연;이휘원;김종환;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.289-290
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    • 2005
  • We have investigated the electro-optical (EO) performances of the flexible liquid crystal display (LCD) on twisted nematic (TN) mode according to variation of cell gap in comparison with glass LCD. There were four kinds of cells which were having cell gaps of 3$\mu$m, 4$\mu$m and 5$\mu$m, especially the lowest 2$\mu$m on flexible and glass substrates separately. The EO performances of the flexible cells on the rubbed potyimide (PI) were almost the same those of glass cells. The response time of flexible cells was shorter than that of glass cells but the alignment of liquid crystal (LC) of flexible cells was weaker than that of glass cells. The residual DC of flexible cells was on the increase like that of glass cells in compliance with lowering cell gap.

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액정 소자의 열적 안전성에 관한 연구 (Study for Thermal Stability of Liquid Crystal Device)

  • 이상극;황정연;서대식;이준웅
    • 한국전기전자재료학회논문지
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    • 제17권4호
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    • pp.439-442
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    • 2004
  • In this study, we investigated about electrooptics characteristic of three kinds of TN cell on the polyimide surface. Monodomain alignments of thermal stressed TN cell over temperature of liquid crystal isotropic phase were almost the same as that of no thermal stressed TN cells. However, the thermal stressed TN cells have many defects. Also, threshold voltage and response time of thermal stressed TN cells show the same performances as no thermal stressed TN cells. There were little changes of value in these TN cells. However, transmittances of TN cells on the polyimide surface decrease with increasing thermal stress time. Finally, the residual DC voltage of the thermal stressed TN cell on the polyimide surface shows decrease of characteristics as increasing thermal stress time. Therefore, the thermal stability of TN cell was decreased by high thermal stress for the long times.

프로젝션 TV 적용을 위한 액정 디스플레이의 열적 및 UV 안전성에 관한 연구 (Study on thermal and UV stability of Liquid Crystal Display for Projection TV Application)

  • 최성호;황정연;배유한;이휘원;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.287-288
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    • 2005
  • In this study, we have investigated electro-optical characteristics of thermal and UV stressed TN cells on the rubbed polyimide surface. Mono-domain alignments of thermal stressed TN cells over temperature of liquid crystal isotropic phase were almost same that of no thermal stressed TN cells. Also, threshold voltage and response time of thermal stressed TN cells were same that of no thermal stressed TN cells. Finally, the residual DC voltage of the thermal stressed TN cell on the polyimide surface show decrease of characteristics as increasing thermal stress time. Therefore, thermal stability of TN cell was decreased by high thermal stress for the long times.

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파라쿼트 농도에 따른 HepG2 세포의 물리적 특성 변화와 실시간 모폴로지 관찰 (Physical Property and Morphology Observation of HepG2 Cells by Various Concentration of Paraquat)

  • 이동윤;강현욱;;권영수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.1232_1233
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    • 2009
  • Paraquat is well-known to cause hepatotoxic responses in human and other mammal species. In solution, it forms free radicals and charge-transfer complex of which formation plays an important role in determination of its biological activity in the presence of various anions. The HepG2 cells were cultured onto a quartz crystal sensor which is possible to detect the density and a viscosity changes using the resonance frequency (F) and the resonance resistance (R). The plot of F-R diagram is able to explain the rheological change of cells onto the surface of the quartz crystal sensor. In this paper, we investigated the physical properties of the HepG2 cells cultured onto a ITO electrode of the quartz crystal sensor according to the paraquat injection at various concentrations (100 mM, 10 mM, 1 mM). We also observed the morphological changes with a micro CCD camera, simultaneously. The HepG2 cells were cultured onto the ITO electrode surface of the quartz crystal modified a collagen film in $CO_2$ incubator. After the paraquat injection, we observed the changes of the morphologies by the micro CCD camera depending on time and analyzed the physical changes of cells on the electrode surface of quartz crystal using F-R diagram. From all results, we proved the effect of paraquat at various concentrations which is led to an apoptosis such as weakening and death of the cells by oxidation and reduction reaction that were produced the superoxide anions and other free radicals.

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태양전지의 반사방지막 (Antireflection coatings for solar cells)

  • 김동섭;이수홍
    • 한국결정성장학회지
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    • 제6권1호
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    • pp.98-106
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    • 1996
  • 반사방지용 코팅은 태양전지에 있어서 아주 중요한 부분중의 하나이다. 태양전지의 표면에서 반사된 빛은 전지의 효율감소와 직결되기 때문에 반사를 줄이기 위한 많은 노력이 진행되어 왔다. 본 논문은 반사방지막의 원리를 소개하고 태양전지에서 반사방지막으로 많이 사용되는 재료의 광학적 성질과 제조방법에 대해서 알아 보았다.

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Room temperature-processed TiO2 coated photoelectrodes for dye-sensitized solar cells

  • Kim, Dae-gun;Lee, Kyung-min;Lee, Hyung-bok;Lim, Jong-woo;Park, Jae-hyuk
    • 한국결정성장학회지
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    • 제30권2호
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    • pp.61-65
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    • 2020
  • The depletion of fossil fuels and the increase in environmental awareness have led to greater interest in renewable energy. In particular, solar cells have attracted attention because they can convert an infinite amount of solar energy into electricity. Dye-sensitize solar cells (DSSCs) are low cost third generation solar cells that can be manufactured using environmentally friendly materials. However, DSSC photoelectrodes are generally produced by screen printing, which requires high temperature heat treatment, and low temperature processes that can be used to produce flexible DSSCs are limited. To overcome these temperature limitations, this study fabricated photoelectrodes using room-temperature aerosol deposition. The resulting DSSCs had an energy conversion efficiency of 4.07 %. This shows that it is possible to produce DSSCs and flexible devices using room-temperature processes.

프로젝션 TV 적용을 위한 액정 디스플레이의 열적 안정성에 관한 연구 (Study on Thermal Stability of Liquid Crystal Display for Projection TV Application)

  • 강희진;황정연;오용철;서대식
    • 한국전기전자재료학회논문지
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    • 제19권11호
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    • pp.1033-1036
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    • 2006
  • We have investigated electro-optical characteristics in three kinds of twisted nematic (TN) cells on the polyimide surface. The threshold voltage and the response time of thermal stressed TN cells were same that of no thermal stressed TN cells. There were little change of value in these TN cells. On the other hand, transmittance of no thermal stressed TN cells were better than that of thermal stressed TN cells. Transmittances of TN cells on the polyimide surface decreased by increasing thermal stress time. Moreover, the residual DC of the thermal stressed TN cells increased as increasing thermal stress temperature and time. Therefore, thermal stability of TN cells were decreased gradually by giving high thermal stress for a long time.

Shearing and Electro-optical Properties of Stressed Cholesteric Liquid Crystal Cells

  • Lee, Jung-Min;Kang, Dae-Seung
    • Journal of Information Display
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    • 제11권2호
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    • pp.91-93
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    • 2010
  • The shearing effects on the electro-optical properties of a stressed cholesteric liquid crystal were investigated. A photopolymer was dispersed in the cholesteric liquid crystal cell. By carefully choosing the mixing ratio between the liquid crystal and the photoreactive monomer, and by applying suitable mechanical shearing on the substrates, a cholesteric liquid crystal display with a low threshold voltage and no alignment layer was demonstrated.

Myricetin Disturbs the Cell Wall Integrity and Increases the Membrane Permeability of Candida albicans

  • Lee, Heung-Shick;Kim, Younhee
    • Journal of Microbiology and Biotechnology
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    • 제32권1호
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    • pp.37-45
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    • 2022
  • The fungal cell wall and membrane are the principal targets of antifungals. Herein, we report that myricetin exerts antifungal activity against Candida albicans by damaging the cell wall integrity and notably enhancing the membrane permeability. In the presence of sorbitol, an osmotic protectant, the minimum inhibitory concentration (MIC) of myricetin against C. albicans increased from 20 to 40 and 80 ㎍/ml in 24 and 72 h, respectively, demonstrating that myricetin disturbs the cell wall integrity of C. albicans. Fluorescence microscopic images showed the presence of propidium iodide-stained C. albicans cells, indicating the myricetin-induced initial damage of the cell membrane. The effects of myricetin on the membrane permeability of C. albicans cells were assessed using crystal violet-uptake and intracellular material-leakage assays. The percentage uptakes of crystal violet for myricetin-treated C. albicans cells at 1×, 2×, and 4× the MIC of myricetin were 36.5, 60.6, and 79.4%, respectively, while those for DMSO-treated C. albicans cells were 28.2, 28.9, and 29.7%, respectively. Additionally, myricetin-treated C. albicans cells showed notable DNA and protein leakage, compared with the DMSO-treated controls. Furthermore, treatment of C. albicans cells with 1× the MIC of myricetin showed a 17.2 and 28.0% reduction in the binding of the lipophilic probes diphenylhexatriene and Nile red, respectively, indicating that myricetin alters the lipid components or order in the C. albicans cell membrane, leading to increased membrane permeability. Therefore, these data will provide insights into the pharmacological worth of myricetin as a prospective antifungal for treating C. albicans infections.

액정 소자의 열적 안전성에 관한 연구 (Study for thermal stability of Liquid Crystal Device)

  • 이상극;황정연;서대식;이준웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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    • pp.9-12
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    • 2004
  • In this study, we investigated about electrooptics characteristic of three kind of TN cell on the polyimide surface. Monodomain alignments of thermal stressed TN cell over temperature of liquid crystal isotropic phase were almost same that of no thermal stressed TN cells. However, the thermal stressed TN cell have many defects. Also, threshold voltage and response time of thermal stressed TN cells show same performances of no thermal stressed TN cells. There were little changes of value in these TN cells. However, transmittances of TN cells on the polyimide surface decrease with increasing thermal stress time. Finally, the residual DC voltage of the thermal stressed TN cell on the polyimide surface show decrease of characteristics as increasing thermal stress time. Therefore, thermal stability of TN cell was decreased by high thermal stress for the long times.

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