Basics of analytical methods used for the investigation of interaction mechanism between cements and superplasticizers

In order to better understand the interactions between cements and superplasticizers (high-range water reducers), various analytical methods have traditionally been applied, but some of these methods can introduce significant errors. In this paper the fundamental interaction mechanisms are reviewed and appropriate methods and sample preparation conditions are explained in detail. For superplasticizer adsorption measurements, analysis by size exclusion chromatography is useful in order to avoid the effect of other organic compounds released from cement by the action of the superplasticizer. For BET specific surface area measurements it is important to avoid pre-drying at over 60 °C, as otherwise ettringite can decompose and strongly increase the surface area. In order to evaluate pore solution chemistry correctly the aqueous phase must be extracted without dilution. In addition, the fluidity performance of many cements in superplasticized concretes can be changed simply by passage through a storage silo, for reasons which are not yet understood.     

Reactive extraction of diols with phenyl boronic acid and trioctylmethylammonium chloride as coextractants and quantitative structure–property relationship of their extraction behaviors

BACKGROUND: Diols that can be produced biologically have attracted much attention because of the increased cost of producing them chemically. The cost of separating the diols from the broth forms a major part of the total cost of microbial production. Reactive extraction using organoboronate is one promising method for recovering diols from the dilute aqueous solution. RESULTS: A basic investigation of solvent extraction of diols was conducted at 303 K employing phenylboronic acid and trioctylmethylammonium chloride as coextractants in the mixed solvent. Both the tetrahedral boronate anion complex and trigonal boronate neutral complex were extracted. 1,3‐diols and vicinal diols were extracted, but 1,4‐diol was not extracted. Extraction equilibrium constants were correlated with the enthalpies of formation of the complexes, which were calculated by molecular modeling with semi‐empirical molecular orbital calculations considering the solvent effect. CONCLUSION: The complex extraction behaviour of diols with phenylboronic acid and quaternary ammonium salt can be predicted by using the quantitative structure–property relationship (QSPR). Copyright © 2009 Society of Chemical Industry     

Oxygen Potential Measurement of Americium Oxide by Electromotive Force Method

The oxygen potentials of AmO_{2− x} were measured in the x range of 0.01–0.5 and the temperature range of 1000–1333 K by the electromotive force method. The oxygen potentials at 1333 K were −19.83 kJ/mol for x =0.019 and −319.1 kJ/mol for x =0.485, which were higher than those of CeO_{2− x} by approximately 200 kJ/mol for the corresponding x values. From the dependence of the oxygen potentials on x and temperature, a tentative phase diagram of Am–O system was proposed, which suggested the presence of the intermediate phases of Am₇O₁₂ and Am₉O₁₆ in the Am–O system.     

Study on sustainable redevelopment of a densely built-up area in Tokyo by introducing a distributed local energy supply system

“Distributed local energy systems” had been expected to rationalize the supply of energy to built-up areas, but until now very little research has been performed to estimate the effect of their application to actual cities. In this research, therefore, a future vision for the year 2030 in the Sancha Area (SANCHA VISION 2030), a typical densely built-up area in Tokyo, has been elaborated including a simulation to estimate benefits from the application of distributed energy systems in terms of reduced energy consumption and CO₂ emissions as well as mitigation of the heat-island phenomenon. As a result, it was demonstrated that a “distributed local energy system”, which provides a district with both electrical power and heat through an integrated distribution system, may contribute to a considerable improvement in energy efficiency for those areas. In addition, it may also provide other benefits, including enhancement of living amenity and urban security in times of emergency.     

Experimental verification of a dynamic voltage restorer capable of significantly reducing energy‐storage element requirements

This paper deals with a dynamic voltage restorer (DVR) characterized by installing the shunt converter at the load side. The DVR can compensate for the load voltage when a voltage sag appears in the supply voltage. An existing DVR requires a large capacitor bank or other energy‐storage elements such as double‐layer capacitors or batteries. The DVR presented in this paper requires only a small DC capacitor intended for smoothing the DC‐link voltage. Moreover, three control methods for the series converter are compared and discussed to reduce the series‐converter rating, paying attention to the zero‐sequence voltages included in the supply voltage and the compensating voltage. Experimental results obtained from a 200‐V, 5‐kW laboratory system are shown to verify the viability of the system configuration and the control methods. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(3): 73–82, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20460     

Effect of soybean varieties on the content and composition of isoflavone in rice-koji miso

To clarify the effect of soybean varieties on isoflavone, a useful component for human health, in soybean products, we investigated changes in the isoflavone content and composition in rice-koji miso, after fermentation/aging for 6 or 12 months using varieties of soybeans (Tohoku-126, Tohoku-135, Tohoku-139, Suzuyutaka and Chinese soybeans), by high performance liquid chromatography. In soybeans, the total isoflavone content in Tohoku-126 was 444 mg/100 g, which was 1.2–2.0 times the content in the other soybean varieties. The malonyl glycosides and aglycones in soybeans accounted for more than 60% and only a few percent, respectively. As for rice-koji miso, the total isoflavone and aglycone contents were the highest in miso prepared from Tohoku-126. The ratios of glycosides to aglycones (80.1–92.6%) in miso were higher than those in the original soybeans. The time course of the isoflavone composition during the fermentation/aging process of rice-koji miso indicated that glycosides decreased from 86.4% to 44.9% after 6 months but aglycones increased from 9.6% to 53.3%.     

Micropatterning of liquid crystalline polyacetylene derivative by using self-organization processes

Side-chain type liquid crystalline polyacetylene, which has mesogenic moieties as side chains, is one of the promising materials for practical applications in the electronics. Micropatterning of the conductive polymer is a significant issue in this field. We show a simple method to fabricate micropatterns of side-chain type liquid crystalline polyacetylene derivative. Under dry condition, stripes patterns and lattice pattern were formed based on the fingering instability and stick-slip motion of the receding meniscus. Honeycomb-patterned polymer film was obtained by casting polymer solution under humid condition. The micropatterns drastically changed by changing solution concentration and preparation conditions.