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  • 1
    Electronic Resource
    Electronic Resource
    Reflective mode of a nematic liquid crystal with chirality in a hybrid aligned configuration (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 1978-1980 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A reflective type of a liquid crystal (LC) display is proposed in a twisted hybrid aligned configuration with a reflective electrode and a single polarizer. A chiral dopant was introduced into a nematic LC to produce a proper amount of twist in a hybrid aligned geometry. Numerical simulations were performed to optimize the cell parameters so that the electro-optical switching between the black and white states could be easily achieved. It was experimentally demonstrated that this reflective mode gives wide viewing and fast response characteristics. The effect of an optical retardation film on the device performance is also discussed. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.121239
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  • 2
    Electronic Resource
    Electronic Resource
    Bistable twisted nematic liquid-crystal optical switch (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 3008-3010 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this letter, we describe a bistable twisted nematic (BTN) liquid-crystal device optimized for use in a fiber optical system. The device configuration is optimized so that the states of polarization for the two bistable states are linear and orthogonal to each other for a linearly polarized input light. This optimization is accomplished by the use of the Poincaré sphere method. Using this method, we obtained the analytical forms of the optimization conditions. Several different optimized conditions are obtained. In order to experimentally explore the use of the BTN structure in optical latching switches, one optimized structure (11.25° and −348.75° twists, dΔn/λ=0.496) is studied in the infrared region by the measurement of the output state of polarization. The experimental results agree well with our theoretical predictions. This study also suggests that transmissive BTN displays with high contrast are possible by the use of these optimized conditions with nonparallel and noncross polarizer configurations. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.125217
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  • 3
    Electronic Resource
    Electronic Resource
    Acoustic generation in liquid crystals (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 1985-1987 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this letter, we report on the acoustic emission from liquid crystals during the electric switching of these materials. The initial observation of the sound was in a bistable nematic liquid crystal. This investigation revealed that a faint, but audible, sound is generated when a liquid crystal is switched from one state to another. We have undertaken a systematic study to investigate the origin of acoustic generation in these materials. By investigating the intensity and frequency of the sound emission, we have concluded that the sound originates as a result of molecular motion, which results in the excitation of the cavity containing the liquid crystal. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.124893
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  • 4
    Electronic Resource
    Electronic Resource
    Defect in the circular-circularly rubbed liquid crystal cell with off-center alignment (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 3005-3007 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this letter, we investigate the behavior of the defects in a circular-circularly rubbed liquid crystal cell with an off-center alignment. We show that the line defect forms a circle that passes through the rubbing centers of the two surfaces. The size and the position of the defect circle depend on the cell gap and the pitch of the materials. We propose a simple model, based on an analysis of the free energy, to explain this interesting phenomenon. This technique of defect making is useful to confine the defect to a particular position by controlling the cell parameters and the material properties. It can also be applied to the pitch measurement, the generation of the space-variant polarized light, and the study of the dynamic properties of the defect. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.126560
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  • 5
    Electronic Resource
    Electronic Resource
    Optimized configuration for reflective bistable twisted nematic displays (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 1225-1227 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this letter, we experimentally verify the operation of a single-polarizer reflective bistable twisted nematic (BTN) liquid-crystal display using an optimized geometry. Based on the polarization optimization using the Poincaré sphere representation, several optimized operating modes, which can simultaneously optimize both bistable states, are possible. One of these optimized configurations, the 67.38° and −292.62° twisted bistable states with 310.69 nm birefringence and a 24.25° incident polarization angle, is studied in detail. The evolution of the state of polarization of light passing through this reflective BTN structure is numerically studied, and the electro-optic property of the reflective BTN structure is experimentally demonstrated. Our results show that, using these optimum configurations, a high-contrast display is possible. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.124649
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of multidirection rubbing on the alignment of nematic liquid crystal (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 513-515 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated the alignment properties of liquid crystals induced by multiple rubbing of the surfaces in different directions. Experiments were carried out using homeotropic and hybrid-aligned samples. It is experimentally found that the alignment of the liquid crystals is along neither of the rubbing directions, but instead lies along an axis intermediate between these two directions, and that the direction depended on the relative strength of rubbing along the two axes. A model that assumed the grooves along two rubbing directions is proposed, and the relation between the orientation of the liquid crystal and the relative rubbing strength is analyzed. We found that this model can explain the observed experimental results. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.127028
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  • 7
    Electronic Resource
    Electronic Resource
    Achromatic linear polarization rotator using twisted nematic liquid crystals (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 3995-3997 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this letter, we propose a simple configuration that is capable of rotating a linear polarization state of light by a certain angle for a wide range of wavelengths. The device consists of three liquid-crystal cells: two homogeneous cells and one twisted nematic (TN) cell. It is well known that a thick TN cell can rotate the linear polarization state of light by following the twisted structure. However, for a thin TN cell, achromatic polarization rotation is not possible. By the use of the Poincaré sphere model of the TN structure, we demonstrate that if one thin homogeneous cell is placed before and another one is placed after a thin TN structure, then a linear polarization state can be transformed close to the eigenmodes of TN. Therefore, this structure can be used to achieve the achromatic polarization rotation. This letter provides a detailed discussion of the theoretical analysis and a demonstration of the achromatic linear polarization rotator by the use of a 1.9 μm TN cell for the wavelength range 450–700 nm. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.126846
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  • 8
    Electronic Resource
    Electronic Resource
    Electrically controllable azimuth optical rotator (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 2334-2336 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The transformation of the state of polarization (SOP) of light from one state to another can be graphically illustrated by a trajectory on the Poincaré sphere (PS). We use this method to illustrate the control of the azimuth SOP rotation on the PS. Traditionally, azimuth rotation is achieved by the use of a Faraday rotator or by the mechanical movements of birefringent wave plates. In this letter, an electrically controllable azimuth optical rotator is introduced theoretically and verified experimentally. It consists of two quarter-wave plates and one liquid-crystal variable wave plate and allows polarization rotation of an arbitrary polarized light by an angle determined by the magnitude of the applied field. This electrical approach avoids the errors and inconvenience associated with the magnetic field and the mechanical movements of other methods. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.126337
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  • 9
    Electronic Resource
    Electronic Resource
    Characteristics and Functional Properties of Protein Isolates from Various Peanut (Arachis hypogaea L.) Cultivars (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 57 (1992), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Protein isolates from 9 cultivars of peanut (Arachis hypogaea L.) were compared. Sephadex G-200 gel filtration and nondenaturing polyacrylamide gel electrophoresis (NPAGE) of the protein isolates showed very similar patterns of arachin and nonarachin fractions. The content of individual fractions was somewhat different among cultivars, possibly indicating genetic variability. Sodium dodecyl sulfate-PAGE (SDS-PAGE) showed that the protein isolates had extremely complex sub-unit compositions. The content of acidic amino acids of the protein isolates was 34–38%, basic was 15–17%. Differences in some functionalities such as solubility and emulsification activity were conspicuous among cultivars.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1992.tb05504.x
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  • 10
    Electronic Resource
    Electronic Resource
    Miscibility and Biodegradability of Poly(Butylene Succinate)/Poly(Butylene Terephthalate) Blends (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 53-66 
    Details
    ISSN: 1572-8900
    Keywords: Miscibility ; biodegradability ; composting test ; transesterification reaction ; poly(butylene succinate) ; poly(butylene terpehthalate)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract As one of the biodegradable polymers, the blend of poly(butylene succinate) and poly(butylene terephthalate) is dealt with in this study. In our previous work, it was demonstrated that PBS and PBT are immiscible not only from the changes of T g but also from logG′–log G″ plots. It is expected that the biodegradability of the blends could be improved by enhancing the miscibility. We tried to induce the transesterification reaction between two polyesters with various time intervals to enhance the miscibility of the blends. The extent of transesterification reaction was examined by 1H-NMR. We utilized a dynamic mechanical thermal analyzer and a rotational rheometer to investigate the changes in miscibility. We also verified the biodegradability of PBS/PBT blends after the transesterification reaction by the composting method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021846219775
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