Development of a thermal voltage converter with calculable high‐frequency characteristics

A thermal‐voltage converter for high‐frequency (HF‐TVC) AC–DC transfer standard has been developed. The HF‐TVC was designed such that the frequency characteristic is calculable from the shape and dimension of the input circuit. A new multi‐junction thermal converter element (JSTC04) has been developed, which has a simple and straight heater configuration to minimize the parasitic impedances in the input circuit. The AC–DC difference of the HF‐TVC was evaluated by two independent methods, with agreement better than 7 µV/V up to 1 MHz. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Influence of shearing history on the rheological properties and processability of branched polymers. IV. Capillary flow and die swell of low-density polyethylene

Low-density polyethylene (LDPE) melts show anomalous rheological behavior; their viscoelastic properties vary with their shearing histories although their molecular structural parameters do not change. Capillary flow and die swell behavior were dependent not only on the experimental conditions such as temperature or shear stress but also on the processing index (PI), which was introduced in a preceding article in order to quantify the anomalous rheological behavior of LDPE melts. In addition, it was found that the flow activation energy at constant shear stress also varied with the shearing histories. The experimental findings are discussed in terms of the rheological flow units of LDPE melts.     

Plastic optical fibre with improved transmittance

A low-loss plastic optical fibre has been manufactured employing polystyrene as core material. The minimum transmission loss was 140 dB/km at 670 nm, and intrinsic material loss of polystyrene was estimated to be 105 dB/km.     

Host egg kairomones essential for egg-larval parasitoid,Ascogaster reticulatus Watanabe (Hymenoptera: Braconidae)

Several components of an internal kairomone were identified inside eggs of the host,Adoxophyes sp. (Lepidoptere: Tortricidae), that releases egg deposition of the egg-larval parasitoid,Ascogaster reticulatus Watanabe (Hymenoptera: Braconidae). Pupal hemolymph with the same activity as an internal host egg kairomone was used as a convenient test sample. Heat-treated pupal hemolymph was chromatographed on a Sephadex G-25 column. Each fraction was bioassayed and reacted with ninhydrin. The active fractions were ninhydrin-positive. Each fraction was placed onto an araino acid analyzer, which showed that the amino acids were most abundant in active fractions. Among 22 amino acids, alanine, arginine, glycine, histidine, isoleucine, leucine, methionine, proline, serine, tryptophan, and valine were active. The mixture of these active amino acids was as active as the egg-mass homogenate at the same ratio and concentration, suggesting that the most important component as the kairomone in a host egg is the mixture of several amino acids.     

A new challenge: grain boundary engineering for advanced materials by magnetic field application

This paper gives an overview of “Grain boundary engineering (GBE) for advanced materials by magnetic field application” based on recent experimental work performed on different kinds of structural and functional materials. It is shown that magnetic field application has a great potential and unique advantage as “non-contact processing” for microstructure control, irreplaceable by any other existing processing methods. The control of grain growth and texture by magnetic fields has been found to be generally applicable to many metallic materials, irrespective of whether they are ferromagnetic or not. Grain growth which is controlled by grain boundary migration was found to be strongly affected by magnetic field application. Recent attempts at the grain boundary engineering by magnetic field application through phase transformation have revealed that magnetic phase transformation can provide us a new approach to grain boundary engineering for iron alloys and steels, as well as a new nanocrystalline material produced by magnetic crystallization from the amorphous state. The possibility of engineering applications of enhanced densification using magnetic sintering and magnetic rejuvenation has been discussed for iron powder compacts and deformation-damaged iron alloys, respectively.     

Influence of shearing history on the rheological properties and processability of branched polymers. II. Optical properties of low-density polyethylene blown films

An investigation was performed to determine how optical properties of LDPE blown films changed when the material was subjected to extrusion shearing. In this study, shearing histories were given to the materials by designed extrusion shearing. Recognizable variations take place in haze and gloss of the blown film during the extrusion shearing. Such variations were expressed as a function of the processing index (PI), which was introduced in a preceding paper as a measure of the memory effect of shearing histories of LDPE. This means that the variations originate in a certain change in the cohesive state of the polymer molecules attributable to the shearing.     

Transmission electron microscopy/electron energy loss spectroscopy measurements and ab initio calculation of local magnetic moments at nickel grain boundaries

We have determined local magnetic moments at nickel grain boundaries using a transmission electron microscopy/electron energy loss spectroscopy method assuming that the magnetic moment of Ni atoms is a linear function of the L₃/L₂ (white-line ratio) in the energy loss spectrum. The average magnetic moment measured in the grain interior was 0.55 μ_B, which agrees well with the calculated magnetic moment of pure nickel (0.62 μ_B). The local magnetic moments at the grain boundaries increased up to approximately 1.0 μ_B as the mis-orientation angle increased, and showed a maximum around 50°. The respective enhancement of local magnetic moments at the Σ5 (0.63 μ_B) and random (0.90 μ_B) grain boundaries in pure nickel was approximately 14 and 64% of the grain interior. In contrast, the average local magnetic moment at the (111) Σ3 grain boundary was found to be 0.55 μ_B and almost the same as that of the grain interior. These results are in good agreement with available ab initio calculations.     

Queueing-Delay Formula for Common-Channel Signaling Systems

An approximate queueing model for common-channel signaling systems has been developed and the queueing-delay distribution has been obtained. As a special case, the approximate average queueing-delay formula for common-channel signaling systems has been derived. By simulation, it has been ascertained that this formula is reasonably accurate.     

Identification of Female Sex Pheromone of the Legume Pod Borer, Maruca vitrata and Antagonistic Effects of Geometrical Isomers

An EAD-active component in a female abdominal tip extract of the legume pod borer, Maruca vitrata (Fabricius) (= M. testulalis), was identified as (E,E)-10,12-hexadecadienal (E10,E12–16:Ald). In laboratory bioassays, the purified synthetic E10,E12–16:Ald with 99% isomeric purity had attractancy to male moths equal to the crude extract. However, the unpurified chemical with 92% isomeric purity did not show any attractancy. Addition of 0.1 ng EZ isomer or 1 ng of EZ, ZE, or ZZ isomers of 10,12–16: Ald to 1 ng of the purified synthetic pheromone antagonized its attractancy as did addition of each isomer to 1 female equivalent of the crude extract. These results suggest that it is necessary to develop formulation and release techniques that maintain extremely high isomeric purity of the synthetic pheromone for male trapping in the field.