Preparation and performance of anatase-loaded porous carbons for water purification

Fine particles of photoactive anatase-type TiO₂ were loaded on activated carbon and carbon spheres through the hydrolysis of titanium oxysulfate under autogenous hydrothermal conditions. Their photoactivity and adsorptivity were evaluated separately by the measurements of relative concentration of methylene blue (MB) and iminoctadine triacetate (IT) remained in the solution either in the dark or under UV irradiation. Activated carbon could adsorb a large amount of MB but only a small amount of IT, and carbon spheres could adsorb only a small amount of MB. Loading of anatase under hydrothermal conditions was found to occur preferentially at the entrance of pores on the surface of substrate carbon in the beginning of deposition and to result in the reduction of specific surface area and consequently of the adsorption rate of MB. Further hydrothermal treatment was found to give homogeneous coverage of the surface of activated carbon by anatase fine particles. By UV irradiation after the saturation of adsorption in the dark, a marked decrease in concentration of MB and IT was observed, which recovered a high adsorptivity of activated carbon. Through repetitive measurements of concentration decrease in the solution in the dark and under UV irradiation, it was proved that MB and IT, which were adsorbed in the dark, could be decomposed under UV irradiation.     

Phosphatidyl inositol-phospholipase C in squid photoreceptor membrane is activated by stable metarhodopsin via GTP-binding protein, Gq

Phosphatidyl inositol-phospholipase C (PI-PLC) in squid retina was studied by immunoblotting and its activities were determined using [3H]phosphatidyl inositol bisphosphate ([3H]PIP2) as substrate. PI-PLC activity was found mostly in soluble fraction when the retina homogenate was treated with 400 mM KCl, but was associated with rhabdomal membranes under low salt conditions (20 mM Hepes). A protein with apparent molecular mass of 130kD was recognized by an antibody against PLC beta 4/norp A in both 400 mM KCl soluble and rhabdomal membrane fractions. A 42 kD protein recognized by antibody against the C-terminus of Gq alpha was also present in these two fractions. GTP gamma S stimulated only the PI-PLC activity associated with membrane and was magnesium dependent. PI-PLC activity was found to be (i) highly dependent upon calcium concentrations, (ii) enhanced by GTP but not by other nucleotides, and (iii) significantly stimulated by light at lower concentrations of GTP gamma S. The stimulation by light was still observed when irradiated membrane was incubated at 10 degrees C for 10 min and then mixed with GTP gamma S. These results suggest that stable metarhodopsin stimulates a PLC beta 4/norp A-like enzyme via a G-protein, Gq.     

Recovery characteristics of a YBCO high-temperature superconducting current-limiting element for use in low-voltage distribution systems

Recovery characteristics of a YBa₂Cu₃O_7-y high-temperature superconductor after its quenching are investigated experimentally in this paper. The zigzag-shape superconducting elements 310 mm in effective length and 1.5 mm × 1 mm in cross section are examined. AC current injection tests are carried out. It is clarified that the high-temperature superconducting element has a quick transition characteristic between the super- and normal-conducting states. The test elements recover to zero impedance state from high impedance state just after removing the over-current when the magnitude of accumulated heats due to the over-current during the quenching period is less than 1 J. Furthermore, it is found from experiments that the critical current level might be reduced by some self-magnetization due to a high current during the quenching period.     

Quenching current level coordination in superconducting power transmission systems

In the present power transmission system, electric power devices are equipped under the concept of insulation coordination and are protected from lightning overvoltage and switching surge by the arrester. However, the future superconducting power transmission system is characterized by the heavy current transmission capability, the lower transmission loss and lightning-surge-free circumstances. Thus, in the superconducting power transmission system, superconducting devices should be protected rather from quenching by the overcurrent of a short-circuit fault than from the breakdown by over-voltage. In this paper, a new concept of the coordination for the superconducting transmission system is proposed as a “quenching current level coordination” instead of the insulation coordination. Furthermore, it is pointed out that the quenching current level coordination has the duality relationship with the present insulation coordination. A superconducting fault current limiter should play an important part of the quenching current level coordination to prevent the other superconducting devices from quenching.     

Synthesis of O-Acyl-L-Homoserine by lipase

Lipases (EC 3.1.1.3) fromCandida cylindracea andRhizopus delemar were found to catalyze O-acylation of L-homoserine or L-serine with free fatty acids or with fatty acids from triacylglycerol. The active pH range of the reation for O-acylation was from 7.0 to 8.5. Emulsifying activity of O-oleoyl-L-homoserine was higher than those of conventional surfactants.     

An application of polyalcohols prepared from diols. I. Elastic polymers with functional groups prepared by chemical modifications

An elastic polymer with hydroxymethyl side chains, which contains some crosslinked structure, has been prepared by treating its prepolymer with maleic anhydride and styrene in the presence of an initiator. Its mechanical properties were varied largely by the molar ratio of the hydroxyl group:maleic anhydride:styrene. A typical example of the polymer showed elongation 69%, tensile strength 0.85 kgf/mm², and Young's modulus 9.4 kgf/mm². Some other modifications are also examined.     

Low distortion 1.3 μm strained-layer MQW-DFB laser for AM-SCMtransmission systems with large channel capacity

1.3-μm strained-layer multiquantum-well distributed-feedback (SL-MQW-DFB) lasers with extremely low distortion and low noise characteristics up to high output-power as well as over wide frequency range were successfully fabricated. This was achieved by both the high relaxation oscillation frequency (f_r) characteristics of the laser with the optimized SL-MQW active structure and the suppression of nonradiative current with relatively long laser cavity length. By using the SL-MQW laser with a 400-μm long cavity as a light source for CATV transmission system, high quality AM-SCM transmissions with the largest channel capacity (151 channel) was demonstrated due to low distortion characteristics at high output power. Also, for the laser with 300 μm long cavity, extremely low bias-current operation (17 mA above threshold) is realized in high quality 100 channel AMSCM transmissions, due to high f_r at low bias-current     

Direct imaging exposure equipment with high overlay accuracy for flexible substrate in roll‐to‐roll method

In order to fabricate thin‐film transistors on a flexible substrate, it is required to overlay patterns with high alignment accuracy. A polymer film can be deformed greatly and easily through thin‐film transistor fabrication processes because the glass transition point of a polymer film is below the maximum temperature of the processes. Furthermore, low stiffness of a polymer film can cause deformation when the polymer film is loaded on a working holder. These matters make it difficult to make patterns directly on a polymer film with high alignment accuracy. We proposed three concepts that solve three technical issues in order to directly make patterns with high overlay accuracy on a flexible film without a support substrate. We developed roll‐to‐roll exposure equipment with high overlay accuracy for a flexible substrate. Using this equipment, we succeeded to directly make patterns on a PET film, achieving a resolution of less than 6‐μm line and space pattern and an overlay accuracy of less than ±5 μm.