Pozzolanic reactivity of fly ash - API method and K-value

The pozzolanic reaction of fly ash in mortar was primarily examined using a K-value from Ferét’s law. As a result, the pozzolanic reaction would be mainly controlled by the diffusion kinetic, and the diffusion constant would increase with water content in the mortar. The K-value is useful to estimate the degree of the pozzolanic reaction of mortar. Secondly, the relation between K-value and assessed pozzolanic activity index derived from accelerated chemical test (API method) was inspected. It is concluded that the API is one of the useful acceleration methods to evaluate the degree of the pozzolanic activity, because API has a good relation with K-value.     

Synthesis of terpolymers having a phospholipid polar group and poly(oxyethylene) in the side chain and their protein adsorption–resistance properties

Terpolymers having phospholipid polar groups were synthesized from 2‐methacryloyloxyethyl phosphorylcholine (MPC), methacryloyl or acryloyl poly(oxyethylene) macromonomers (POEM) [(CH₂CH₂O)_n (where n = 2–23); PEOM(2), PEOM(23), ME(9), Ph(6)], and n‐butyl methacrylate (BMA). The characteristics of these terpolymer membranes were investigated by water content (H) and X‐ray photoelectron spectroscopy. The content of water in the terpolymer increased with increasing content of MPC and length of oxyethylene units. The membranes of terpolymers were found to adsorb bovine serum albumin much less than those of poly(methyl methacrylate) and poly(BMA). Even though the contents of MPC in the terpolymer were 5 to 25 mol %, the terpolymer depressed BSA adsorption more than poly(MPC‐co‐BMA) consisting of 29 mol % of MPC. The use of terpolymer with POEM can decrease the amount of MPC in the polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1092–1105, 2002     

Preparation of spherical nanocomposites consisting of silica core and polyacrylate shell by emulsion polymerization

Nanocomposite particles consisting of silica (inorganic core) and polyacrylate (organic shell) were prepared in a form of emulsion by a new and simple method—the emulsion polymerization of acrylic monomers in the presence of silica sol. The key technique of the present emulsion polymerization, which made the formation of the nanocomposites successful, is the usage of nonionic surfactant above its cloud point. The morphology of the composite was investigated by DLS, AFM, and TEM, which clearly showed formation of the core‐shell‐type particles. A transparent film was prepared by casting the emulsion, which showed high resistibility against organic solvents. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 659–669, 2006     

Transductions of dags and trees

Directed acyclic graphs (dags) model derivations of phrasestructure grammars analogously to the way that trees model derivations of context-free grammars.In this paper we introduce translations of such dags which naturally extend the bottom-up tree translations. Composition results of these dag-to-tree transformations are studied. It is shown that every recursively enumerable tree language can be obtained from a recognizable dag language by such a transduction. Tree languages obtained from some subsets of recognizable dag languages by these transductions are investigated.The work of the first author was supported in part by University of Kansas General Research allocation #3015-20-0038.     

A simplified simulation method for selecting the most effective off-site protective action

In order to facilitate a number of calculations needed to quantify effectiveness of off-site protective actions for various emergency scenarios for emergency planning of nuclear facilities, we developed a simplified simulation method for selecting the most effective protective action among candidates of action. The protective actions considered are sheltering in houses, sheltering in public concrete building, evacuation, and iodine prophylaxis. The method has functions of (1) simulating the movement of members of the public under protective actions and calculating avertable dose by protective actions in short computing time, and (2) selecting the most effective protective action for divided areas around a nuclear site. To achieve short computing time in function (1), we applied a multivariate analysis method by using sample data obtained from results calculated with a program for simulating the movement of members of the public under protective actions with a detailed mathematical model that requires long computing time. As to function (2), we focused on net benefit, namely avertable dose minus an intervention level, of a protective action. Intervention levels used are those that IAEA proposed based on justification and optimization of protective actions by taking account of benefit and disadvantage due to protective actions. Analysis results by the simplified simulation method showed good agreement with those by the detailed simulation program. Application of the simplified method to a model nuclear site demonstrated that the method was useful as it provided the most effective protective action area depending on source terms, meteorological conditions, and so on.     

A Microprocessor-Based Current Controller with an Internal Current-Rate Loop for Motor Drives

A new current-control method that is suitable for microprocessor-based speed regulation of motor drives is described. The method achieves fast-response and high-accuracy performance by using a major current loop and an internal current rate loop. The former loop is used to control precisely the mean value of the motor current by employing a current feedback signal obtained from a smoothing filter of the rippled current. The latter loop is used to stabilize the major loop with a high gain and to limit the variation rate of the motor current by employing the current feedback signal obtained from the instantaneous current without time delay. A current controller using a microprocessor was trail-manufactured and tested with a thyristor-converter-driven dc motor. It was found that fast-controlled current response can be obtained, even with a relatively long sampling period.     

Lowering of Preparation Temperatures of Anatase Nanocrystals-Dispersed Coatings via Sol–Gel Process with Hot Water Treatment

A longer period of time was necessary to form anatase nanocrystals on silica–titania gel coatings at lower hot water treatment temperature, whereas considerable amounts of anatase nanocrystals were observed even at 38°C after a treatment of 65 h. The coatings pre-heated at 60°C for 1 h and treated with hot water at 55°C for 15 h showed higher photocatalytic activity for methylene blue bleaching than the coatings prepared under the conditions with higher processing temperature close to 100°C. Such a high photocatalytic activity of the coatings obtained through low processing temperatures can be ascribed to a large specific surface area of the coatings and a smaller crystal size of the precipitated anatase.     

Information system development by business process modeling based on adaptability to specification changes

Business modeling has been attracting attention in the development of information systems to be used for analyzing and designing the working procedures of the system under development. In this paper, we propose a method of information system development by business process modeling based on adaptability to specification changes. The proposed method builds a business process model from the requirement specifications, translates the model into UML, identifies the elements bridging the translation from Business Process Modeling to UML, that is, the analytical stage and the design stage, and seeks to perform both processes continuously while finalizing the design. The proposed method was applied to the prototyping of a bus booking and management system, comparing the results using only UML for the configuration with those obtained by using the proposed method. The proposed method proved effective in the early detection and removal of bottlenecks, in accurate modeling, and in adjusting to changes in the specifications. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(2): 54–64, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21045     

Nano-scaled hydroxyapatite/polymer composite III. Coating of sintered hydroxyapatite particles on poly(4-methacryloyloxyethyl trimellitate anhydride)-grafted silk fibroin fibers

A novel composite coupling between nano-scaled hydroxyapatite (HAp) particles and poly[4-methacryloyloxyethyl trimellitate anhydride (4-META)]-grafted silk fibroin (SF) through ionic interaction was synthesized. The weight gain of poly(4-META) by graft-polymerization increased with increasing the reaction time, eventually reaching a plateau value of about 20 wt%. The HAp nano-particles were adsorbed equally and dispersively on the treated SF fiber surface. The HAp content in the composite was 4.554 wt% ± 0.098 (n = 4), confirmed by thermogravimetry (TG). This synthetic system requires no heat to connect HAp to SF and is useful when applying to non-heat-resistant polymers. The L-929 cell-adhesion test shows that the HAp/SF composite improves bioactivity compared to the original SF.     

Improvement of Jc and Grain Alignment of Bi-2212/Ag Multilayer Tapes by Pre-Annealing and Intermediate Rolling Process

The high transport critical current density (J _c ) > 500 kA/cm ² at 4.2 K, 10 T is obtained in the Bi-2212/Ag multilayer tapes fabricated by using PAIR (Pre-Annealing and Intermediate Rolling) and melt-solidification process. This J _c value is twice higher than existing high-quality Bi-2212/Ag tapes (250 kA/cm ² ). By applying PAIR process to Bi-2212/Ag tapes, Bi-2212 grain alignment is much improved and a large J _c enhancement is achieved. J _c has been increased strongly by performing pre-annealing at 840°C in oxygen (1 atm) and intermediate rolling with 25% deformation.