Decreasing the initial irreversible capacity loss of graphite negative electrode by alkali-addition

The effect of alkali function group contained in electrode binder was investigated. Carboxy methyl cellulose (CMC) improved the initial irreversible capacity loss in graphite negative electrode. Lithium acetate also improved the initial cycle efficiency. On the other hand, ethyl cellulose (EC) and hydroxyl propyl methyl cellulose (HPMC), which do not have a carboxylic group, did not decrease the reductive electrolyte decomposition. After charge and discharge cycle, the surface film composition on the electrode with CMC was less than on the electrode without CMC. This suggests that a carboxylic group in the binder acted as a catalyst and promoted the solid electrolyte interphase (SEI) formation which prevents the excess electrolyte decomposition on the graphite electrode.     

Synthesis of BaAl2S4:Eu2+ Electroluminescent Material by the Polymerizable Complex Method Combined with CS2 Sulfurization

Eu-activated BaAl₂S₄ (BaAl₂S₄:Eu) blue light emission phosphor has attracted considerable attention recently as a prospective material for full color electroluminescent display applications. Although BaAl₂S₄:Eu was discovered over 30 years ago, the solid-state reaction between metal sulfides in sealed quartz ampoules remains the main method for the synthesis of this material. In this work, a homogeneous single-phase Ba_0.95Eu_0.05Al₂S₄ (BaAl₂S₄:Eu) phosphor was obtained by the sulfurization–reduction of the multicomponent oxide precursor in a CS₂ atmosphere at 1050°C. The oxide precursor containing barium, aluminum, and europium for this process was prepared by the polymerizable complex method, which ensures a high degree of homogeneity in the final product. The BaAl₂S₄:Eu material thus obtained exhibited a single emission line at 475 nm and a fluorescence intensity of 35% compared with one of the best commercially available (Ba,Eu)MgAl₁₀O₁₇ phosphors.     

Microprocessor-Based Decoupled Control of Manipulator Using Modified Model-Following Method with Sliding Mode

A methodology of discontinuous feedback and continuous feedforward control is developed to achieve accurate decoupled tracking in a class of nonlinear, time varying systems in the presence of disturbances, parameter variations and nonlinear dynamic interactions. The method is based on an improved variable structure control with a sliding mode.     

Evaporation-induced pattern formation in polymer films via secondary phase separation

The ordered necklace-like or cellular pattern formation has been investigated for ternary polymer solutions in which primary and secondary phase separations were induced by the solvent evaporation. The patterns consisted of regular droplet arrays of various diameters, which arose in the pre-existing polymer phases via the secondary phase separation. The pattern formation was enhanced with increasing air velocity and ambient humidity, while it was suppressed with decreasing initial film thickness. The regular pattern was independent of surface wettability of the solid substrate. We ascribe the morphology change to the evaporation-induced surface tension driven convection, which re-arranged the droplet distributions from disordered to flow-induced ordered patterns.     

Influences of nonuniformity in metal concentration in gate dielectric silicate on CMIS inverters'' propagation delay time

It is shown that propagation delay time in CMIS (complementary metal insulator semiconductor field effect transistor) inverters is strongly affected by dielectric constant nonuniformity in gate dielectrics caused by the phase separation in silicate films. Influences of such nonuniformity on load capacitance are studied by analytical calculations based on a physical model which takes polarization into account. It is newly found that load capacitances are affected by the phase separation in qualitatively different ways, depending on the average metal concentration of their dielectric films. An experimental result is compared with those calculations. Influences of such nonuniformity on current drivability are studied by 3-dimensional device simulations. It is also newly found that such nonuniformity affects load capacitance and current drivability in different ways, resulting in an increase in propagation delay time of CMIS inverters for all metal concentrations studied. An explanation of this phenomenon is given with physical considerations.     

The effect of material difference and flange nominal size on the sealing performance of new gasketless flanges

This paper deals with a new seal system between flange joints without using a gasket. This gasketless flange includes a groove and an annular lip that is machined in one of the flange rings which when removed being in contact with the other flange to form a seal line when the flanges are assembled. In this study, firstly, fundamental dimensions are examined for unplasticized polyvinyl chloride (PVC-U JIS) to obtain the best sealing performance. Then, the effects of material difference and flange nominal size upon the sealing performance of the new gasketless flange are investigated for two types of materials, 0.25% carbon steel (S25C JIS) and PVC-U. It is found that the critical internal pressure at which leakage appears is mainly controlled by the maximum stress at the annular lip for each material even if the flange nominal sizes are different. The gasketless flange made by PVC-U shows the higher critical internal pressure compared with the case of S25C if the same clamping forces are applied. The effect of stress relaxation for PVC-U on the sealing performance is also considered. Then, it may be concluded that this PVC-U gasketless flange as well as S25C has good sealing performance.     

Surface structure and visible light photocatalytic activity of titanium–calcium hydroxyapatite modified with Cr(III)

The synthetic titanium–calcium hydroxyapatite (Ti–CaHap) particles were treated with different concentrations of aqueous Cr(NO₃)₃·9H₂O solution and the materials obtained were characterized by a variety of conventional techniques. The crystal structure and particle morphology of Ti–CaHap were essentially not altered by treating with Cr(III) solution. With increasing the Cr(III) concentration, the amount of Cr(III) in the products was increased and that of Ca(II) was decreased. XPS results revealed that the surface state of Cr of Ti–CaHap was trivalent. These facts allow us to infer that the Cr(III) was doped by substitution of surface Ca(II) of Ti–CaHap. Besides, IR results proved that increasing the Cr(III) concentration developed the surface Cr–OH band while the surface Ti–OH and P–OH bands of Ti–CaHap vanished. This imply that the formation of surface P–O-Cr(OH)₂ and Ti–O–Cr(OH)₂ groups, resulting the Cr(OH)₃-like layer on the surface of Ti–CaHap particles. The Cr(III)-doped Ti–CaHap possessed the absorption peaks at 446 and 623 nm in vis range in addition to the UV absorption of charge transfer transition of O^2? → Ti⁴⁺. The vis absorption peaks developed on raising the Cr(III) concentration. The photocatalytic decomposition of acetaldehyde into CO₂ over Cr(III)-doped Ti–CaHap was detected under vis irradiation and the activity was lowered by the formation of Cr(OH)₃-like layer on the particle surface.     

Growth and poliovirus production of Vero cells on a novel microcarrier with artificial cell adhesive protein under serum-free conditions

A microcarrier is used for the three-dimensional (3D) culture of adhesion-dependent mammalian cells. We developed a novel microcarrier by binding ProNectin F, an artificial cell adhesive protein synthesized by genetically engineered Escherichia coli to a polyacrylic superabsorbent polymer. The microcarrier is characterized by containing no animal-derived components. The serum-free culture of Vero cells for vaccine production using the microcarrier increased the number of Vero cells by approximately 30% compared with the existing dextran beads coated with porcine Type I collagen, which resulted in approximately a 30% to 40% increase in the infectivity titer of the Sabin 2 strain of poliovirus. These results suggested that the developed microcarrier should be unprecedented in permitting high-yield vaccine production by means of a serum-free culture.     

Optimization of antireflection coating for VO2-based energy efficient window

Vanadium dioxide (VO₂) films have been proposed as energy efficient window coatings for their thermochromism, with which the solar energy transmission in the IR region may be controlled passively. These coatings suffer from low visible (or luminous) transmission (380–760 nm in wavelength), which hinders their practical uses. We here consider an antireflection (AR) coating for the VO₂-based window. Optical calculation was first performed upon a basic structure for thermochromic window composed of a VO₂ layer on glass with an AR layer of refractive index n and thickness d. Optimization was carried out on n and d for a maximum integrated luminous transmittance (T_lum). The calculation demonstrates that the optimal n value changes with thickness of VO₂, and at n≈2.2 it gives the highest T_lum enhancement from 32% (without AR coating) to 55% for 50-nm VO₂. Experiment was done on a structure of 50-nm VO₂ on quartz glass using ZrO₂, of which n≈2.2 matching the best n value, as AR coating. Formation of an optimized structure, ZrO₂ (56 nm)/VO₂ (50 nm)/quartz, was done by sputtering, and its optical properties were characterized with spectrophotometry. An improvement of T_lum from 32.3% to 50.5% was confirmed for the semiconductor phase with similarity also for the metallic one. The IR switching properties were not much deteriorated.