• 제목/요약/키워드: crystal form

검색결과 677건 처리시간 0.026초

Fabrication of Light Aggregates Using the Fly Ash-Clay Slurry

  • Seunggu Kang;Lee, Kigang;Kim, Jungwan
    • 한국결정성장학회:학술대회논문집
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    • 한국결정성장학회 1998년도 PROCEEDINGS OF THE 14TH KACG TECHNICAL MEETING AND THE 5TH KOREA-JAPAN EMGS (ELECTRONIC MATERIALS GROWTH SYMPOSIUM)
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    • pp.81-86
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    • 1998
  • The light aggregates were fabricated by sintering green bodies made form the fly ash-clay alip. The content of fly ashes in the slip could be increased up to 70wt.% due to controlled rheological behavior of the slip, and the green body of uniform microstructure could be obtained by DCC(Direct Coagulation Casting)method. The apparent density, microstructure and compressive strength for sintered bodies fired at 1100∼1200$^{\circ}C$ were evaluated. The properties of light aggregates fabricated depend on slip density, particle behavior in the slip and sintering conditions. The sintered body prepared by firing a green body made from slip of density 1.60 at 1150$^{\circ}C$/2hr satisfied conditions of a light aggregate as apparent density of 1.49${\pm}$0.02 and compressive strength of 584${\pm}$62kg/$\textrm{cm}^2$.

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Minimally Complex Problem Set for an Ab initio Protein Structure Prediction Study

  • Kim RyangGug;Choi Cha-Yong
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제9권5호
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    • pp.414-418
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    • 2004
  • A 'minimally complex problem set' for ab initio protein Structure prediction has been proposed. As well as consisting of non-redundant and crystallographically determined high-resolution protein structures, without disulphide bonds, modified residues, unusual connectivities and heteromolecules, it is more importantly a collection of protein structures. with a high probability of being the same in the crystal form as in solution. To our knowledge, this is the first attempt at this kind of dataset. Considering the lattice constraint in crystals, and the possible flexibility in solution of crystallographically determined protein structures, our dataset is thought to be the safest starting points for an ab initio protein structure prediction study.

편광 흡수성 광기전성 고분자 박막 연구 (Polarizing Photovoltaic Polymer Films for Reflective Solar-LCDs)

  • 김영찬;허윤호;박병주
    • 한국전기전자재료학회논문지
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    • 제25권7호
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    • pp.525-530
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    • 2012
  • We present the results of a study of the polarizing photovoltaic (PV) effects in an aligned polymer bulk heterojuction PV layer. The fairly uniform in-plane uniaxial alignment of the PV layer with a macroscopic axial orientational order parameter of 0.40 was achieved by means of a simple rubbing technique. Moreover, reflective polarizing PSCs having the aligned PV layers were applied to power-generating reflective type liquid crystal displays (LCDs), which exhibited a maximum contrast ratio of 1.7. These results form a promising foundation for various energy harvesting polarization dependent opto-electrical LCD device applications.

A new precharging method without side effects for liquid crystal displays with insufficient charging time

  • Lee, Seung-Hyuck;Kim, Jongbin;Lee, Seung-Woo
    • Journal of Information Display
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    • 제13권3호
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    • pp.125-130
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    • 2012
  • In this paper, a new precharging method without any side effects is proposed to overcome image degradation caused by insufficient charging times. This work explains why the precharging method can compensate for short charging times. However, side effects of the precharging method in the form of horizontal line artifacts are addressed, wherein line artifact-compensating precharging (LCP) is presented to mitigate the side effects. Behavioral modeling is employed to investigate the side effects by estimating transient responses of a liquid crystal display. The LCP proves that it can dramatically reduce line artifacts caused by precharging because the brightness difference of adjacent pixels does not exceed 1.0.

Synthesis of Novel Morpholine Appended Crystal violet lactone Derivatives and an Investigation of Their Thermochromic Behavior

  • Kim, Myeong Jin;Muthukumar, Palanisamy;Angupillai, Satheshkumar;Son, Young-A
    • 한국염색가공학회지
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    • 제30권1호
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    • pp.1-8
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    • 2018
  • In the present study, three morpholine substituted crystal violet lactone (CVL) have been synthesized to monitor the thermochromic property. This work is explaining the role of substituent on the lactone ring. The methyl substituents induced greater chromic effects than the chloro substituents. Furthermore, the three-component mixtures that contained CVL, bisphenol-A, and methyl stearate were used to analyse the thermochromic effect of the CVLs as bulk samples with various temperature. The thermochromic properties of the CVLs were evaluated using solid-state UV-Vis and FT-IR spectroscopic techniques. Finally, one of the synthesized CVL has been successfully converted into the form of a test paper similar to pH paper for use as thermal indicators.

Wide Viewing Angle Flexible Color Liquid Crystal Display

  • Liu, Kang-Hung;Lin, Yan-Rung;Chang, Ku-Hsien;Liao, Chi-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.357-360
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    • 2005
  • A novel wide viewing angle flexible liquid crystal display will be demonstrated. The crossed matrix-type micro-cell structure was adopted in this design. The LC domains were divided into four different tilted directions by the combination effect of pixel fringe field and crossed matrix type micro-cell. It can create four domains without rubbing process and form the cell gap without spacer. For flexible color fabrication, a novel inkjet printing technology is adopted. This cost effective wide viewing angle color flexible LCD technology can be a good solution for high performance flexible LCD.

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The crystal and molecular structure of $\gamma$-hydroxy-.$\beta$-amino butyric acid

  • Kim, Yang-Bae
    • Archives of Pharmacal Research
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    • 제8권1호
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    • pp.1-6
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    • 1985
  • The crystal structure or $\gamma$-hydroxy-$\betha$-aminobutyric acid was determined by MULTAN system with X-ray intensity data on a diffractometer and refined by the least-squares method to an R-value 0.034 for 711 reflections. The crystals were orthorhombic, space group $P2_{1}2_{1}2_{1}$, Z = 4, with a = 10.220, b = 8.257 and c = 6.556$\AA$. The molecule takes the zwitterionic form and skeletal conformation is trans-transform. The molecules are held together by intra-and intermolecular NH-O and OH--O hydrogen bonds.

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50kW 단결정 태양광 발전시스템 운전특성연구 (A Study on Working Characteristic of 50kW single crystal Photovoltaic System)

  • 안상현;김병현;박지홍;안형근;한득영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.194-195
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    • 2007
  • This paper presents the experimental operation of invertactive 50kW photovoltaic system for monitoring periods. Form these performance monitoring results, the PV system performance has been evaluated and analyzed for component perspective. It has produced a regression equation. Using the equation, it is possible to estimate the annual electricity generation. The result of this study will be used to determine the appropriate capacity of PV system in different systems.

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탄소 나노 튜브가 분산된 수평전기장을 이용한 액정 셀의 액정 방향성과 전기 광학특성 연구 (Orientation of Liquid Crystal and Electro-Optic Characteristic Effect of dispersed Carbon nanotubes in In Plane Switching Cell)

  • 전상연;백인수;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.520-521
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    • 2005
  • To observe the orientation of carbon nanotubes (CNTs) dispersed in nematic liquid crystal (NLC), CNT-doped homogeneously-aligned NLC cells driven by in-plane field was fabricated. The CNTs were aligned with a LC director in the initial state, whereas the CNTs disturbed the LC director above critical ac field. We observed motional textures in the form of vertical stripes in the local area between electrodes, which were associated with a deformation of the LC director orientation. This suggests that CNTs start to vibrate three dimensionally with translational motion. The hysteresis studies of voltage-dependent transmittance under dc electric field show that the amount of residual dc is greatly reduced due to ion trapping by CNT.

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Synthesis and Crystal Structure of Zinc Iodide in the Sodalite Cavities of Zeolite A (LTA)

  • Kim, Seok-Han;Park, Man;Son, Young-Ja;Lee, Hyung-Joo;Jeong, Gyo-Cheol;Bae, Myung-Nam;Lim, Woo-Taik
    • Bulletin of the Korean Chemical Society
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    • 제28권4호
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    • pp.567-573
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    • 2007
  • The crystal structure of ZnI2 molecule synthesized in zeolite A (LTA) has been studied by single-crystal X-ray diffraction techniques. A single crystal of |Zn6|[Si12Al12O48]-LTA, synthesized by the dynamic ion-exchange of |Na12|[Si12Al12O48]-LTA with aqueous 0.05 M Zn(NO3)2 and washed with deionized water, was placed in a stream of flowing 0.05 M KI in CH3OH at 294 K for four days. The resulting crystal structure of the product (|K6Zn3(KI)3(ZnI2)0.5|[Si12Al12O48]-LTA, a = 12.1690(10) A) was determined at 294 K by single-crystal X-ray diffraction in the space group Pm3m. It was refined with all measured reflections to the final error index R1 = 0.078 for 431 reflections which Fo > 4σ (Fo). At four crystallographically distinct positions, 3.5 Zn2+ and nine K+ ions per unit cell are found: three Zn2+ and five K+ ions lie on the 3-fold axes opposite 6-rings in the large cavity, two K+ ions are off the plane of the 8-rings, two K+ ions are recessed deeply off the plane of the 8-rings, and the remaining a half Zn2+ ion lie on the 3-fold axes opposite 6-rings in the sodalite cavity. A half Zn2+ ion and an I- ion per unit cell are found in the sodalite units, indicating the formation of a ZnI2 molecule in 50% of the sodalite cavities. Each ZnI2 (Zn-I = 3.35(5) A) is held in place by the coordination of its one Zn2+ ion to the zeolite framework oxygens and by the coordination of its two I- ions to K+ ions through 6-rings (I-K = 3.33(8) A). Three additional I- ions per unit cell are found opposite a 4-ring in the large cavity and form a K3I2+ and two K2ZnI3+ ionic clusters, respectively.