• Title/Summary/Keyword: ChLC

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Improving switching time from homeotropic state to planar state in cholesteric liquid crystal by olymer stabilization

  • Kim, Tae-Jin;Lim, Tong-Kun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.437-438
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    • 2005
  • A polymer stabilization method is employed to reduce the transition time from field-induced homeotropic(H) state to reflecting planar(P) state in the cholesteric liquid crystal(ChLC) display. To stabilize ChLC by polymer, we mixed ChLC with diacrylate of 2 $wt%{\sim}6$ wt%. Two samples were made with different method of stabilization. For one sample the diacrylate of 2 wt% was polymerized with the ChLC in P state, while for the other sample diacrylate of 16 wt% was polymerized with ChLC in H state. In the former case, the transition time was 1000 times faster then those in the pure sample. In the latter sample, the transition time was 1700 times faster than those in pure ChLC sample.

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LC Aligning Ability of the Liquid Crystal Display using Photopolymer Layers Containing an Acrylate unite Photopolymerized by a Photoinitiator

  • Hwang, Jeoung-Yeon;Seo, Dae-Shik;Kim, Jun-Young;Kim, Tae-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.489-492
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    • 2003
  • Photoalignment materials of PGMAcr, poly[3-(acryloyloxy)-2-hydroxypropyl methacrylate] using an acrylate unit photopolymerized by a photo-initiator and PGMA4Ch, poly[3- (4-ehalconyloxy)-2-hydroxypropyl methacrylate] using photodimerization by the chalcone group were synthesized. Also, the liquid crystal (LC) alignment capabilities on the photopolymer layers were studied. A good LC alignment with UV exposure on the PGMAcr surface can be obtained. However, LC alignment defects were observed on the PGMA4Ch surface. The LC alignment capability of the PGMAcr surface by the photoinitiator was better than that of the PGMA4Ch surface by the chalcone group which is a photosensitive moiety.

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Liquid Crystal Alignment Effect on the PGMAcr surface (PGMAcr 표면을 이용한 액정배향 효과)

  • 황정연;김준영;서대식;김태호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.11
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    • pp.1014-1018
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    • 2003
  • A photoalignment material of a PGMAcr, poly[3-(acryloyloxy)-2-hydroxypropyl methacrylate] using a photopolymerized the acrylate unit by photo-initiator and a PGMA4Ch, poly[3(4-chalconyloxy)-2-hydroxypropyl methacrylate] using a photodimerization by chalcone group were synthesized. Also, the liquid crystal (LC) aligning capabilities on the photopolymer layers were studied. A good LC alignment with UV exposure on the PGMAcr surface can be obtained. However, the LC alignment defects were observed on the PGMA4Ch surface. The LC aligning capabilities of the PGMAcr surface by photo-initiator were better than that of the PGMA4Ch surface by chalcone group as photosensitive moiety.

Liquid crystal alignment effects for the photo-aligned VA-LCD on the photo-polymer

  • Hwang, Jeoung-Yeon;Seo, Dae-Shik;Hahn, Eun-Joo;Kim, Jae-Hyung
    • Transactions on Electrical and Electronic Materials
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    • v.1 no.3
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    • pp.10-13
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    • 2000
  • In this study the new photo-alignment material copoly(PM4Ch-ChMa)(copoly (poly (4-methancryloyloxy)chalcone-cholesteryl methacry late)) was synthesized, Also, the liquid crystal (LC) aligning capabilities and the electro-optical(EO) characteristics for the photo-aligned vertical-aligned(VA)-LC display(LCD) were studied. The monodomain alignment of the NLC for the photo-aligned VA-LCD by linearly polarized UB exposure on the Photo-dimerized copoly(PM4Ch-ChMA) surface was observed,. Excellent Voltage-transmittance characteristics for the VA-LCD photo-aligned by polarized UV exposure on the copoly (PM4Ch-ChMA) surfaces for 1 min was achieved. The response time of the VA-LCD photo-aligned by polarized UV exposure on the copoly (PM4Ch-ChMA) surfaces for 1 min was 39.3 ms, We suggest that the photo-dimerized chacone group increased with increasing UV exposure time, which then contributes to a low response time of the photo-aligned VA-LCD on the copoly (PM4Ch-ChMA) surfaces.

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Optical Simulation of Multicolor Cholesteric Liquid Crystal Displays Using Finite-Difference Time- Domain (FDTD) Method

  • Ding, J.M.;Ting, C.L.;Lin, Y.R.;Chen, R.D.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1142-1145
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    • 2006
  • The Finite-difference time-domain (FDTD) method is used to directly solve Maxwell's equations, and the techniques required for optical simulation of Bragg reflections of cholesteric liquid crystal (ChLC) displays are introduced in this paper. The simulated results show that the color gamut of a ChLC display can be broadened by using of a circular polarizer on top surface of the ChLC film, and are examined by experiments.

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Study on generation of pretilt angle using a methacrylic copolymers having cholconyl and cholesteryl groups. (Chalconyl과 Cholesteryl group을 가진 methacryl계 공중합체를 이용한 프리틸트 발생에 관한 연구)

  • 황정연;서대식
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.7
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    • pp.625-629
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    • 2000
  • We synthesized a new copoly (PM4Ch-ChMA) copoly(poly(4-methacryloyloxy) chalcone-cholesteryl methacrylate) having chalconyl and cholesteryl moiety for homeotropic liquid crystal(LC) alignment. Pretilt angles of nematic(N) LC generated by linearly polarized UV exposure on the copolymer surfaces were investigated. Good thermal stabilities of the synthesized copolymer were obtained by TGA (Thermogravimetric Analysis) measurement. Pretilt angles of the NLC decreased with increasing UV exposure time on the copolymer surfaces. We consider that the pretilt angle of the NLC is attributed to increased chalcone by increased UV exposure time. High pretilt angle of the NLC is attributed to increased chalcone by increased UV exposure time. High pretilt angle of 81$^{\circ}$was observed after the UV exposure for 3 min.

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Fertilization Efficiency of Livestock Manure Composts as Compared to Chemical Fertilizers for Paddy Rice Cultivation

  • Kang, Chang-Sung;Roh, An-Sung
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.1
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    • pp.86-92
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    • 2012
  • To promote the practical use of livestock manure compost (LC) for paddy rice cultivation, the fertilization efficiency of nutrients in LCs was investigated compared to that of chemical fertilizer. This experiment was conducted at rice field in Hwaseong, Korea, with 6 treatments by each of 3 kinds of tested LCs, cattle manure compost (CaC), swine manure compost (SwC) and chicken manure compost (ChC). The treatments consisted of 3 application levels of LCs and 3 chemical fertilizer treatments having the same application levels with LCs. $NH_4$-N content in soil became higher according to the increase in the urea application rate, while it became lower in LC plots than in urea plots, and statistically had no significant difference among LC plots. There was a close relationship between phosphate fertilization rate and the increment of soil available phosphate content after experiment resulting y = 0.1788x - 6.169 ($R^2=0.9425$) when applied fused superphosphate fertilizer, and y = 0.0662x - 2.689 ($R^2=0.9315$) when applied LC at the equivalent rates to phosphate input (x: phosphate application rate, kg $ha^{-1}$, y: increment in soil available phosphate content, mg $kg^{-1}$). And from these two equations, the correlation on the phosphate application rate between fused superphosphate fertilizer and LC could be obtained as y = 2.7056x - 52.492 (x: $P_2O_5$ application rate of fused superphosphate, kg $ha^{-1}$, y: $P_2O_5$ application rate of LC, kg $ha^{-1}$). Plant height, number of tillers, nutrients uptake by rice, and rice yield showed higher levels in N 100% and N 150% application plots of chemical fertilizers, while every LC plots exhibited lower values and no significant difference among them. Relative nitrogen fertilization efficiencies of LCs compared to urea was 12.3% for CaC, 8.8 for SwC and 24.6 for ChC, respectively.

Confirmation of carbamate pesticides by liquid chromatography coupled with electrospray ionization mass spectrometry (LC/MS를 이용한 카바메이트계 잔류농약 확인방법)

  • 박준조;금모래;고광춘;박병옥;이성식
    • Korean Journal of Veterinary Service
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    • v.25 no.1
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    • pp.23-29
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    • 2002
  • A method was developed to separate, detect and qualify aldicarb, bendiocarb, carbaryl, carbofuran, ethiofencarb, methomyl, methiocarb, propoxur in meats and fruits. Experimental beef and fork samples were fortified with 0.05mg/kg of carbamate pesticides for analysis. Carbamate-detected pear by HPLC fluorescence detector(HPLC/FLS) are extracted with acetonitril and refined by solid phase extraction(SPE) filled with aminopropyl-bonded silca, In the following step, the injected materials into LC/MS are analyzed to result in the fact that bendiocarb, carbaryl, carbofuran, ethiofencarb, methomyl, methiocarb, propoxur presents several sorts of fraction ions following with; [M+H]$^{+}$, [M+Na]$^{+}$,[M-CONH$CH_3$]$^{+}$, [M-OCONH$CH_3$]$^{+}$. In addition, ethiofencarb presents [M-SCH$_2$$CH_3$]$^{+}$ ion distinctive and aldicarb presents [M+Na]$^{+}$ and [M-OCONH$CH_3$]$^{+}$ ion which is the most decisive fraction ion for pesticides such as bendiocarb, carbaryl, carbofuran, ethiofencarb, methiocarb, methomyl, propoxur excluding [M+H]$^{+}$ ion. However, [M-OCONH$CH_3$]$^{+}$ and [M-OCONH$CH_3$]$^{+}$ fraction ion charactering carbamate pesticides are detected most efficiently with fragment voltage 50ev. As a result, for rluantitative analysis, [M+Na]$^{+}$ ion is the most decisive ion for detection of aldicarb and [M+H]$^{+}$ ion is the most decisive fraction ion for Pesticides such as bendiocarb, carbaryl, carbofuran, ethiofencarb, methiocarb, methomyl, propoxur. Carbaryl-detected pear by HPLC/FLS are analyzed by L/MS and the result shows that [M+H]$^{+}$ and [M-CONH$CH_3$]$^{+}$ ions charactering carbaryl are detected.ering carbaryl are detected.

Evaluation of Apparent Ileal and Standardized Ileal Digestibility of Amino Acid in Feed Ingredients to Alterate the Protein Sources for Weaned Pigs (자돈에서 대체 단백질 원료사료의 외관상 회장 아미노산 소화율 및 표준 회장 아미노산 소화율 평가)

  • Choi, Yo-Han;Kim, Dong-Woo;Kim, Jin-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.358-365
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    • 2020
  • This study was conducted to evaluate the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids in feed ingredients for use as protein sources in swine feed. A total of six weaned pigs (Landrace×Yorkshire×Duroc, 14.4±0.35kg) surgically fitted with a T-cannula in the distal ileum were used in this study and were randomly allotted to a 6×6 Latin square design. Corn germ, corn gluten meal (CM), corn gluten feed (CF), chlorella (CH), and lysine co-product (LC) were used for evaluation, and the experimental periods of each ingredient included 5 days for adaptation and 2 days for collection. CH and LC had significantly higher (p<0.05) AID of lysine (79.1% and 78.7%, respectively). The AID of methionine was not significantly different among all feed ingredients. The AID of threonine of CH was significantly higher (p<0.05) than those of other ingredients and was 81.8%. CH, LC, and CM had higher (p<0.05) SID of lysine (80.4%, 79.5%, and 77.0%, respectively). The SID of methionine showed no difference among all treatments. CH showed 81.8% SID of threonine, which was significantly higher (p<0.05) than LC and CF. In conclusion, chlorella and lysine co-product showed the greatest AID and SID of amino acids, which makes them potentially valuable feed ingredients for use as protein sources in swine feed.

Electro-optical characteristics of photo-aligned VA-LCD using a new photo-polymer (새로운 광 폴리머를 이용한 광배향 VA-LCD의 전기 광학 특성)

  • Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04a
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    • pp.181-184
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    • 2000
  • A new photo-alignment material, copoly (PM4Ch-ChMA), copoly (poly (4-methacryloyloxy) chalcone-chalconemethacryl) was synthesized and the electro-optical (EO) characteristics for the photo-aligned vertically aligned (VA)-LC display (LCD) were investigated. The monodomain alignment of the NLC for the photo-aligned VA-LCD by linearly polarized UV exposure on the photo-dimerized copoly (PM4Ch-ChMA) surfaces was observed. Excellent voltage-transmittance characteristics for the photo-aligned VA-LCD by UV exposure for 1 min. on the copoly (PM4Ch-ChMA) surfaces were achieved. The response time of the photo-aligned VA-LCD by UV exposure on for 1 min. the copoly (PM4Ch-ChMA) surfaces was about 39.3 ms. The response time for the photo-aligned VA-LCD decreased with increasing UV exposure time.

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