High-rate reduction of copper oxide using atmospheric-pressure inductively coupled plasma microjets

Reduction of copper oxide was performed using an atmospheric-pressure inductively coupled plasma (AP-ICP) microjet while varying the input power P between 15 and 50 W. Cuprous oxide (Cu₂O) and cupric oxide (CuO) were formed on the sputtered Cu surface by thermal annealing. Dynamic behavior of the microplasma jet, optical emission from H atoms, the substrate temperature, chemical bonding states of the treated surface, and the thickness of the reduced Cu layer were measured to study the fundamental reduction process. Surface composition and the thickness of the reduced Cu layer changed significantly with P. Rapid reduction of CuO and Cu₂O was achieved at a rate of 493 nm/min at P = 50 W since high-density H atoms were produced by the AP-ICP microjet.     

Bacteriological and chemical evaluation of overseas mineral waters

Overseas and imported mineral waters were subjected to visual examination, tested for standard plate count and heterotrophic bacteria, and also analyzed to determine the concentrations of several anions and cations. Some products showed turbidity or color, and several had standard plate count and/or heterotrophic bacteria. One imported natural mineral water product had a high level of standard plate count, and the levels differed with the lot. Tests for total coliform bacteria, Escherichia coli, fecal streptococci, and Pseudomonas aeruginosa were negative on additional testing of samples having standard plate counts of more than 100. The fluoride concentration of one European region sample exceeded the production standard of the Food Sanitation Act in Japan (raw water: less than 2 mg/L) and most of the products lacked the warning labels which are mandatory for fluoride concentrations over 0.8 mg/L. These results indicate that none of the raw water for mineral waters was seriously polluted, but insufficient sterilization of the bottle or cap or contamination with air-borne microbes during the production process was probably responsible for the pollution. Attention needs to be paid to fair labeling, such as no sterilization/no sterile filtration and high fluoride concentration.     

Possible abilities of dietary factors to prevent and treat diabetes via the stimulation of glucagon‐like peptide‐1 secretion

There is a pressing need for countermeasures against diabetes, which has increased in incidence, becoming a global issue. Glucagon‐like peptide‐1 (GLP‐1), a molecule secreted in enteroendocrine L cells in the lower small and large intestines, is thought to be one of the most important molecular targets for the prevention and treatment of diabetes. There has been increasing interest in the possible ability of dietary factors to treat diabetes via modulating GLP‐1 secretion. There is thought to be a close relationship between incretin and diet, and the purported best approach for using dietary factors to increase GLP‐1 activity is promotion of secretion of endogenous GLP‐1. It have been reported that nutrients as well as various non‐nutrient dietary factors can function as GLP‐1 secretogogues. Here, we present our findings on the GLP‐1 secretion‐stimulating functions of two dietary factors, curcumin and extract of edible sweet potato leaves, which contain caffeoylquinic acid derivatives. However, it is necessary to reveal in greater detail the stimulation of GLP‐1 secretion by dietary factors for preventing and treating diabetes. It is desirable to clarify the exact GLP‐1 secretory pathway, the effect of metabolites derived from dietary factors in gut lumen, and the relationship between incretin and meal.     

Development of microbubble aerator for waste water treatment using aerobic activated sludge

In large-scale waste water treatment plants, the aerobic biochemical reactor is the most important process, where the oxygen supply into the microorganisms often limits the overall waste water treatment rate. On the other hand, several kinds of microbubble distributors have been developed to enrich the oxygen dissolution in water. Therefore, the application of microbubbles for a waste water treatment system was investigated in this study.The oxygen absorption performance of typical microbubble generators was compared with typical bubble generators. To evaluate each bubble generator, the liquid-phase volumetric oxygen transfer coefficient, gas hold-up and power consumption per unit liquid volume were measured in a bubble column attached to each bubble generator. All the microbubble generators allowed the oxygen to dissolve faster than the typical aerators. The spiral liquid flow type microbubble generator had the highest oxygen transfer coefficient even at a low air flow rate although it used more energy than the typical distributors.To improve an industrial waste water treatment system, a novel aeration system utilizing a spiral liquid flow type microbubble generator was proposed in this study. The present system has some advantages such as compact size, portability and fast oxygen dissolution rate. To ensure the performance for organic waste water treatment, the effects of the aeration rate, dissolved oxygen concentration and device properties on the specific consumption rate of model organic waste were investigated. For the novel aeration system, the most suitable conditions to treat organic waste were found.     

Effect of pH on the properties of protonated polyaniline-based films for pH sensing applications

The chemical and physical properties of protonated polyaniline (PANI)-based films, including PANI-emeraldine salt (ES) and PANI/polyvinyl acetate (PVAc) films, before and after pH treatments are characterized and compared. Protonated PANI-based films are prepared by spin coating. The effects of pH value and immersion time on the film properties are investigated to gain a better understanding of their performance in pH sensing. The films are characterized based on color, morphology, chemical structure, phase state, and protonation state. Protonated PANI-based films exhibit a color change from green to dark blue as deprotonation occurs in solutions with higher pH. The highly porous structure of PANI/PVAc films is slightly affected by the pH of the solution. However, the globular structure of the PANI-ES films forms cracks with increasing immersion time. PANI/PVAc films exhibit better stability in acidic and neutral solutions than in alkaline solutions because of the hydrolysis of PVAc. Compared with the negligible differences in the PANI/PVAc film in buffers with different pH, PANI-ES exhibits noticeable changes. Therefore, PVAc improves the stability and performance of PANI for pH-sensing applications.     

Application of a dispersed autonomous voltage control system to a real high‐voltage distribution network

This paper focuses on the application results of the dispersed autonomous voltage control system, which the authors have proposed, to a real distribution network. This system is effective for regulating the supply voltage of an entire HV line within an optimum range. In the system configuration, an SCC is installed together with an SC and/or ShR on the line. Individual SCCs autonomously control the operation of SCs and/or ShRs based on the voltage measured where the SCs and/or ShRs are located on the line. A field test on a real high‐voltage distribution network found that the proposed system could sustain a high fault tolerance ability and also be cost‐effective in regulating line voltage. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(1): 27–36, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10252     

Structural Analysis of a New Layered Compound: La0.05Sr0.95MnO3

We have found a new phase of La_0.05Sr_0.95MnO₃ with a 30-layer rhombohedral structure by using electron microscopy. The lattice constants were hexagonal axes of a = 0.5444 nm and c = 6.7582 nm. Both weak and strong intensities appeared in selected area diffraction (SAD) patterns. The strong intensities were caused by the periodicity of 15 (Sr,La)O₃ layers that had a new stacking sequence of (cchch)₃. However, the weak intensities indicated that the 15-layer structure has modulation along the c -direction that is twice as long as that of the structure indicated by the strong intensities. We concluded that the modulation of the 30-layer structure was produced by the introduction of two kinds of oxygen octahedra, Mn³⁺O₆ and Mn⁴⁺O₆.     

Metal-containing cured resins based on divalent metal salts of ethylene glycol-methacrylate-maleate

Divalent metal salts of ethylene glycol-methacrylate-maleate in the amorphous state were easily soluble in styrene, methyl methacrylate and ethyl acrylate, to give homogeneous, curable mixtures with high metal content. The viscosities of the mixtures varied depending on the metal present. The mixtures were copolymerized to give metal-containing cured resins of increased compressive strength and Rockwell hardness. Moreover, heat distortion temperature could be improved by introducing Mg or Ca. Of the cured resins studied, the Mg-containing resin showed the best physical properties. Resistance of the metal-containing resins to attack by organic solvents was generally high, whereas greater degradation by aqueous reagents was noted. The thermal behavior of the resins is discussed.     

Discriminating the indistinguishable sapwood from heartwood in discolored ancient wood by direct molecular mapping of specific extractives using time-of-flight secondary ion mass spectrometry

A new method that can chemically discriminate the visually indistinguishable sapwood from heartwood in discolored woods is presented in this paper. Discriminating between sapwood and heartwood, which are normally recognized by color in cross sections of stems of tress, is important in dendrochronological dating, as well as in evaluating qualities of woods such as durability. In tree-ring chronology, the felling date, which affects the construction date of architectures, can be estimated only in woods that have a recognizable sapwood/heartwood boundary. However, the felling date cannot be estimated in discolored woods because it has indistinguishable sapwood. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis of specific chemical substances retained for approximately 1300 years after felling demonstrated the presence of sapwood in a discolored ancient architectural wood of Hinoki cypress (Chamaecyparis obtusa). Direct molecular mapping by TOF-SIMS clearly indicated that the specific substances, hinokinin, hinokiresinol, hinokione, and hinokiol, started to accumulate at the sapwood/heartwood boundary where only hinokinin was localized and retained predominantly in ray parenchyma cells. The result allowed the determination of the felling date of the discolored wood. TOF-SIMS has shown to be useful for investigating the distribution of minute amounts of chemical components in woods.