Surface modification on thermoplastic olefins by low‐temperature cascade arc discharge‐air plasmas for enhanced adhesion with primer

Improvement of primer adhesion to thermoplastic olefins (TPOs) by surface modification with a low‐temperature cascade arc discharge‐air plasmas was investigated. Air plasma with a low‐temperature cascade arc plasma torch can be used for improving the primer adhesion to TPOs. Tape‐adhesion tests (ASTM 3359‐92a method) demonstrated this improvement with a rating of “0” for untreated TPOs and “5” for air plasma‐modified TPOs at certain plasma conditions even for aging at 60 °C and 80% relative humidity for 5 days. The adhesion to primer for the soft and flexible kind of TPOs (ETA‐3041c and ETA‐3101) was easily enhanced. The adhesion to primer for the hard and brittle TPOs (ETA‐3183) needs to optimize the plasma conditions to pass the wet‐adhesion test using air plasmas. To relate the surface characteristics of air plasma‐modified TPOs to adhesion performance with primer, the wettability and polarity of TPOs were evaluated by the contact‐angle measurements of primer and deionized water to TPOs. TPO surface morphology was evaluated using scanning electron microscopy. The surface composition was characterized with electron spectroscopy for chemical analysis. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 623–637, 2002; DOI 10.1002/polb.10122     

Stereoscopic Full-Color Light Emitting Diode Display Using Parallax Barrier for Different Interpupillary Distances

The viewing areas of stereoscopic full-color light emitting diode (LED) displays using parallax barriers are investigated for viewing by observers with different interpupillary distances. We have developed stereoscopic full-color LED displays using three types of parallax barriers for different interpupillary distances. Experiments on distance perception of stereoscopic targets have been conducted with the stereoscopic LED displays using parallax barriers, as well as a stereoscopic LED display using polarizing eyewear. It was shown that enlargement of the viewing area allows several viewers with different interpupillary distances to view a stereoscopic image. It is suggested that parallax barriers designed for narrower interpupillary distances than the viewer’s own provide a viewer with stereoscopic perception.     

Differences in muscle thickness and echo intensity between stroke survivors and age- and sex-matched healthy older adults

Objective: The stroke survivors exhibit change in muscle quantity and quality compared to healthy older adults. This study aimed to compare the muscle thickness (MT) and echo intensity (EI) values of individual muscles between stroke survivors and age- and sex-matched healthy older adults. Methods : In total, 27 stroke survivors and 34 healthy older adults participated in this study. The MT and EI values of the following muscles were assessed from transverse ultrasound images: rectus abdominis (RA), external oblique, internal oblique, transversus abdominis, rectus femoris, vastus intermedius (VI), vastus lateralis (VL), vastus medialis (VM), tibialis anterior (TA), gastrocnemius (Gas), and soleus (Sol). The MT and EI values of these muscles were compared between stroke survivors and healthy older adults. Results : The MT values of the VL, VM, and RA on the non-paretic sides were significantly higher and those of the TA, Gas, and Sol on the paretic sides were significantly lower in the stroke survivors than in the healthy older adults (P < 0.05). The EI values of the VI, VL, VM, TA on the paretic sides and those of the Gas on both the paretic and non-paretic sides were significantly higher in the stroke survivors than in the healthy older adults (P < 0.05). Conclusion : Stroke survivors seem to develop muscle hypertrophy of the non-paretic thigh muscles owing to a compensatory strategy. In addition, the lower-leg muscles on the paretic side of stroke survivors tend to show both quantitative and qualitative muscle changes.     

Mesomorphic Characteristics of Induced Chiral Nematic Phase of [Smectic LCP,PS(4BC/DM)/Nematic LC,E7/Chiral Dopant,CB-15]-Ternary Composite System

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Morphology control of liquid crystalline composite gels based on molecular self-assembling kinetics

Liquid crystalline composite gels consisting of a low molecular mass gelator and a low molecular mass liquid crystal were prepared by two types of gelation method (continuous cooling and isothermal gelating), which provide different molecular self-assembling kinetics of the low molecular mass gelator as gelation proceeds. Optical microscopy and atomic force microscopy revealed that numerous fine strands of the one-dimensionally assembled low molecular mass gelators were formed in the composite gels for both the continuous cooling method and the isothermal gelating method. However, the thinner strands were more homogeneously dispersed in the isothermal gelation product at an appropriate temperature, than in the continuous cooling process. This difference in dispersion state of the strands was shown (by polarizing optical microscopy) to have a significant influence on the molecular alignment of the low molecular mass liquid crystal in the liquid crystalline composite gel. The electro-optical response and light scattering-transmitting switching, of the liquid crystalline composite gel in an applied electric field was extremely dependent on the morphology of the gelators. High contrast light switching was achieved for the composite prepared by isothermal gelation. The response time of electro-optical switching was less than 100 µs under 30 V_rms.     

Methane plasma polymerization by low‐temperature cascade arc discharge for enhanced adhesion of primer to thermoplastic olefins

Improvement of primer adhesion to thermoplastic olefins (TPOs) by methane plasma polymerization with a low‐temperature cascade arc discharge was investigated. Methane plasma with a low‐temperature cascade arc plasma torch can be used for improving the primer adhesion to TPOs. Tape‐adhesion tests (ASTM 3359‐92a method) demonstrated this improvement, with a rating of 0 for untreated TPOs and 5 for methane plasma‐polymerized TPOs at certain plasma conditions even for aging at 60 °C and 80% relative humidity for 5 days. The adhesion to primer for the soft, flexible TPOs (ETA‐3041c and ETA‐3101) was easily enhanced. The adhesion to primer for the hard and brittle TPOs (ETA‐3183) needs to optimize the plasma conditions to pass the dry‐ and wet‐adhesion test with methane plasmas. To relate the surface characteristics of methane plasma‐polymerized TPOs to adhesion performance with primer, the wettability and polarity of TPOs were evaluated by the contact‐angle measurements of primer and deionized water to TPOs. TPO surface morphology was evaluated with scanning electron microscopy. The surface composition was characterized with electron spectroscopy for chemical analysis. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2004–2021, 2003     

Measurement of Spatial Distributions of Electron Density and Electron Temperature in Direct Current Glow Discharge by Double Langmuir Probes

The spatial distributions of electron temperature and density in a dc glow discharge that is created by a pair of planar electrodes were obtained by using double Langmuir probes. The contribution of double Langmuir probes measurement is to provide a relatively quantitative tool to identify the electron distribution behavior. Electrons gain energy from the imposed electric field, and electron temperature (T_e) rises very sharply from the cathode to the leading edge of the negative glow where T_e reaches the maximum. In this region, the number of electrons (N_e) is relatively small and does not increase much. The accelerated electrons lose energy by ionizing gas atoms, and T_e decreases rapidly from the trailing edge of the negative glow and extends to the anode. N_e was observed to increase from the cathode to the anode, which is due to the electron impact ionization and electron movement. The electron density was observed to increase with increasing discharge voltage while the electron temperature remained approximately. At 800 V and 50 mTorr argon glow discharge, Te ranged from 15 to 52 eV and Ne ranged from 6.3×10⁶/cm³ to 3.1×10⁸/cm³ in the DC glow discharge, and T_e and N_e were dependent on the axial position.     

Spatial and Temporal Properties of a Nonlinear Optical Feedback System

We experimentally investigate the spatial and temporal properties of a nonlinear optical system composed of an optically addressed spatial light modulator and a two-dimensional optical feedback. The system property is examined using fringes with only one spatial wave vector. The fringes are spontaneously generated using a spatial frequency filter in the optical feedback. We also experimentally investigate the properties of the spatial light modulator in the system using ordinary interference fringes in order to compare with the system property. We demonstrate that the spatial frequency response of the nonlinear optical system is identical to that of the spatial light modulator. We also demonstrate the distinctive temporal behavior of diffraction lights from the fringes generated in the system.     

Elastic constant measurement of Ni-base superalloy with the RUS and mode selective EMAR methods

This paper reports the elastic constants of the Ni-base single crystal superalloy (TMS-26) with a rafted (lamellar) structure having tetragonal symmetry. The elastic constants have been measured at room temperature with the resonance ultrasound spectroscopy method and the mode-selective electromagnetic acoustic resonance method. The value of the elastic constant C33 (250.4 GPa) is almost equal to that of c11 (252.5 GPa), which indicates that the rafted structure virtually has the elastic anisotropy of cubic system.