Incorporation of polyaniline into macropores of three-dimensionally ordered macroporous carbon electrode for electrochemical capacitors

Three-dimensionally ordered macroporous (3DOM) carbons having walls composed of mesosized spherical pores were prepared by a colloidal crystal templating method. A composite electrode consisting of bimodal porous carbon and polyaniline (PAn) was prepared by electropolymerization of aniline within the macropores of the bimodal porous carbon. It was found that the deposition of PAn decreased the porosity and specific surface area (SSA) of the electrode. The electrochemical properties of the composite electrode were characterized in a mixed solution of ethylene carbonate (EC) and diethyl carbonate (DEC) containing 1 mol dm⁻³ LiPF₆. The discharge capacity of the carbon–PAn composite electrode was 111 mAh g_carbon–PAn⁻¹ in the potential range of 2.0–4.0 V vs. Li/Li⁺, which corresponded to a volumetric discharge capacity of 53 mAh cm⁻³. Both the double-layer capacity (30 mAh g⁻¹) and the redox capacity of PAn (81 mAh g⁻¹) contributed to the discharge capacity of the composite electrode. The carbon–PAn composite showed good rate capability, and the discharge capacity at a high current density of 6.0 A g⁻¹ was as high as 81 mAh g⁻¹.     

Micropatterning of emitting layers by microcontact printing and application to organic light-emitting diodes

The microcontact printing (μCP) technique, which is a simple and low damage fabrication technique for thin films, was successfully applied to fabricate patterned emitting layers such as polyfluorene (PF). We fabricated micropatterns by transferring dried and uniform thin films, and observed strong electroluminescence (EL) from the fabricated organic light-emitting diodes (OLEDs) with the patterned emitting layers. The performance of the fabricated device was superior to that of a conventionally fabricated device. This demonstrates the well-controlled interfaces achieved by μCP. Furthermore, we succeeded in fabricating OLEDs with multiple emitting layers. These results show that this technique is promising for application to cost-effective, high luminance and multicolored OLED displays.     

Oxygen Content in ß-Si3N4 Crystal Lattice

ß-Si₃N₄ crystals were obtained through the heat treatment of alpha-Si₃N₄ powder with additives, Y₂O₃:SiO₂= 1:2 and 2:1, and subsequent acid treatments that removed the secondary phases. The lattice oxygen contents of these crystals were determined by the hot-gas extraction method to be 0.258 ± 0.006 and 0.158 ± 0.003 wt% for the additive compositions of Y₂O₃:SiO₂= 1:2 and 2:1, respectively. The oxygen dissolved in the ß-Si₃N₄ crystal lattice as much as in the alpha-Si₃N₄ crystral lattice prepared by the chemical vapor deposition process and in the AlN crystal lattice that exhibited high thermal conductivity.     

Experimental Evidence for the Anisotropic Ostwald Ripening of β-Silicon Nitride

A powder mixture of α-Si₃N₄, Y₂O₃, and SiO₂ was heat-treated in a loose powder state in the temperature range of 1750°–1900°C for 2 h; then, the mixture was acid-rinsed to remove the glassy phase. The widths and lengths of the resulting β-Si₃N₄ crystals were analyzed quantitatively. The width–aspect-ratio distribution of the β-Si₃N₄ crystals initially showed a strong negative correlation, and then the aspect ratio of crystals with small widths quickly decreased. After a stage in which aspect ratio was almost constant, regardless of the width, the width-aspect-ratio distribution evolved to show a positive correlation in the final stage. This pattern of morphology evolution of the β-Si₃N₄ crystals was in good agreement with that predicted by the anisotropic Ostwald ripening model.     

Mixed-model assembly line scheduling using the Lagrangian relaxation technique

The increasing market demand for product variety forces manufacturers to design mixed-model assembly lines on which different product models can be switched back and forth and mixed together with little changeover costs. This paper describes the design and implementation of an optimization-based scheduling algorithm for mixed-model compressor assembly lines at Toshiba with complicated component supply requirements. A separable integer optimization formulation is obtained by treating compressor lots going through a properly balanced line as undergoing a single operation, and the scheduling goal is to delivery products just in time while avoiding possible component shortage. The problem is solved b y using Lagrangian Relaxation (LR). Several generic defects of LR leading to slow algorithm convergence are identified based on geometrical insights, and are overcome by perturbing/ changing problem parameters. Numerical testing shows that near-optimal schedules are efficiently obtained, convergence is significantly improved, and the method is effective for practical problems. The system is currently under deployment at Toshiba     

Advanced motion control by multi‐sensor‐based disturbance observer

Motion control has been widely used in industry applications. One of the key technologies of motion control is a disturbance observer, which quarries a disturbance torque of a motion system and realizes a robust acceleration control. The disturbance observer can observe and suppress the disturbance torque within its bandwidth. Recent motion systems have begun to spread in society and are required to have the ability to make contact with the unknown environment. Such a haptic motion requires a much wider bandwidth. However, since the conventional disturbance observer attains the acceleration response by the second‐order derivative of position response, the bandwidth is limited because of the derivative noise. This paper proposes a novel structure of a disturbance observer. The proposed disturbance observer uses an acceleration sensor for enlargement of bandwidth. Generally, the bandwidth of an acceleration sensor is from 1 Hz to more than 1 kHz. To cover the DC range, the conventional position sensor‐based disturbance observer is integrated. Thus, the performance of the proposed multisensor based disturbance observer (MSDO) is superior to the conventional one. The MSDO is applied to position control (infinity stiffness) and force control (zero stiffness). The experimental results show the viability of the method proposed. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Measurements of activation cross sections of (n,p) and (n, α) reactions in the energy range of 3.5–5.9 MeV using a deuterium gas target

Activation cross sections of (n, p) and (n, α) reactions were measured by means of the activation method in the neutron energy range of 3.5–5.9 MeV using a deuterium gas target. The irradiated target isotopes were ²⁷Al, ^28,29Si, ⁴¹K, ⁵¹V, ⁶¹Ni, ⁶⁵Cu, ^64,67Zn, ⁶⁹Ga, ⁷⁹Br, ⁹²Mo and ⁹³Nb. The cross sections of the ²⁹Si(n, p) ²⁹Al, ⁶⁷Zn(n, p) ⁶⁷Cu, ⁶⁹Ga(n, p) ^69mZn, ⁷⁹Br(n, p) ^79mSe, and ⁶⁹Ga(n, α) ⁶⁶Cu reactions were obtained for the first time in the studied energy range. The d-D neutrons were generated by the deuterium gas target at the Van de Graaff accelerator (KN-VdG) at Nagoya University. All cross section values were determined relative to those of the ¹¹⁵In(n, n′)^115mIn reaction. The activities induced by the low-energy neutrons were corrected. For the corrections, the neutron spectra and mean neutron energies at the irradiation positions were calculated taking into account the energy loss of incident deuterons, the angular differential cross section of the d-D reaction and the solid angle subtended by the sample. The systematics of the (n, p) reactions at the neutron energy of 5.0 MeV in the mass range between 27 and 92 were proposed for the first time. This systematics can predict the cross sections within an accuracy of a factor of 1.6.     

Rapid Preparation of Lead Titanate Sputtering Target Using Spark-Plasma Sintering

PbTiO₃ sputtering targets 8 cm in diameter were prepared using spark-plasma sintering (SPS) for relatively short periods, ∼2 min. Submicrometer-sized PbTiO₃ powders with a relatively large size distribution were densified to ∼86% of the theoretical X-ray density using the SPS process. In contrast, large-sized (8 cm in diameter) ceramics could not be prepared from starting powders with a relatively narrow particle-size distribution. Formation of cracks in the large PbTiO₃ targets was observed when samples were prepared under higher pressures (>50 MPa) or at higher temperatures (>900°C). Crack formation was attributed to unrelaxed internal stress originating from lower pore contents and from an inhomogeneous distribution of cations in the ceramics prepared under these conditions.     

Molecular-weight-controlled polymerization of styrene with Mn(acac)3 in combination with organic halides

Summary The control of molecular weight of polymers in polymerization of styrene (St) with manganese(III) acetylacetonate [Mn(acac)₃] in the presence of organic halides (RX) in toluene at 80°C was investigated. In the polymerizations of St with Mn(acac)₃ in combination with benzyl bromide (BzBr) as RX, the molecular weight of the polymer increased with polymer yields, and the relationships between the molecular weight of polymer and polymer yield gave a straight line passing through the original point. However, the molecular weight distribution was not narrow, but kept almost constant (M_w/M_n was about 2) throughout the polymerization. The mechanism of the polymerization of St with Mn(acac)₃-BzBr was also discussed. Received: 18 December 2000/Revised version: 19 April 2001/Accepted: 25 April 2001     

Preparation of epoxy resin/acrylic composite latexes by miniemulsion polymerization method

Epoxy resin/acrylic composite latexes were prepared by miniemulsion polymerization. Epoxy resins have a functional epoxy group in them and excellent characteristics, such as heat resistance and good adhesion. Acrylic latexes have weather and water resistance. Combining the epoxy resin and the acrylic latex was an attempt to actualize these advantages. The miniemulsion polymerization method was effective in obtaining the composite latex. A less than 500‐nm droplet size for the monomer preemulsion was necessary to obtain the latex in a stable manner. Dimethylaminoethylmethacrylate and methacrylic acid as the reactive functional monomer with an epoxy group were introduced to the latexes. The effect of the polymerization method of these functional groups on the properties of latexes and their films was investigated. The latex prepared by the two‐stage polymerization method had good polymerization stability, storage stability, and solvent resistance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 128–133, 2001