Performance study of analytical method for ethoxyquin in fruit

A performance study of an analytical method of ethoxyquin (ET) in apples and pears was conducted. In the proposed method, the sample was homogenized with thiourea and ET was extracted with acetone instead of hexane used in the official analytical method for ET, in order to improve the extraction efficiency. Furthermore, dibutyl hydroxytoluene was added in the test solution to prevent the decomposition of ET. For evaluation of the method. ET spiked into apples and pears at the level of 0.2 microgram/g was determined in replicate in six laboratories. Mean recoveries from apple, pear and Japanese pear were 85.3, 83.0 and 83.9%, respectively. Repeatability relative standard deviation values were 3.8-4.7% and reproducibility relative standard deviation values were 7.8-11.3%. The detection limits were 0.001-0.025 microgram/g in the six laboratories; this value may reflect instrument performance. ET spiked into apples and pears at the level of 0.2 microgram/g was detected by both LC/MS and GC/MS.     

Spontaneous copolymerizations of 2-phenyl-1,3,6,2-trioxaphosphocane with α,β-unsaturated acids and with α-keto acids

Summary 2-Phenyl-1,3,6,2-trioxaphosphocane(1), an eight-membered cyclic phosphonite, was copolymerized with,ß-unsaturated acids and with -keto acids. The copolymerization took place above room temperature without added catalyst. The copolymerizations of1 with ,ß-unsaturated acids of acrylic and methacrylic acids (2) afforded polyphosphinates (3), alternating copolymers of1 and2. On the other hand, the combinations of1 with -keto acids of pyruvic and phenylglyoxylic acids (5) gave copolymers (6) consisting of alternating unit6 and -ester unit6ß formed via the deoxygenation of5 by1 (Deoxy-Copolymerization).On leave from the Institut of Chemistry, Academia Sinica, Beijing, China     

A nonionic hydrogel from the telechelics by utilizing living polymerization of 2-oxazolines

N,N′-dimethyl-2,2′-tetramethylene-bis(2-oxazolinium) bis(methyl-p-toluene sulfonate) ( II ), a cationic polymerization initiator, was synthesized by the reaction of methyl p-toluene sulfonate with 2,2′-tetramethylene-bis-2-oxazoline ( I ) and a cationic ring-opening polymerization of 2-methyl-2-oxazoline [MeOZO] in the presence of ( II ) was carried out to produce poly(MeOZO) telechelics with various molecular weights. These telechelics were hydrolyzed with an aqueous solution of sodium carbonate to obtain hydroxy terminated telechelics of poly(MeOZO). A series of nonionic polyurethane hydrogels was prepared by the crosslinking reactions of the poly(MeOZO) glycol with pluriisocyanates in the presence of ferric acetylacetonate and DMF as the catalyst and reaction medium, respectively. The hydrogels showed good swelling degrees for water and hydrophilic solvents such as DMF, and bad swelling degree for a hydrophobic solvent such as toluene.     

Air-bearing surface chemical modification for low-friction head–disk interface

As a chemical modification of slider air bearing surface (ABS), fluorine ion implantation (FII) was conducted. FII treated ABS was fabricated to reduce slider surface energy, which is expected to reduce adhesion and friction force between the slider and disk. Tribological performance, such as slider flyability, was experimentally investigated. Touchdown speed, corresponds to a flying height of about 0.4 nm, was reduced by FII treatment. Slider touch-down and take-off hysteresis was also improved by reducing the adhesive force of the lubricant by fluorine-ion implantation. AE output and friction force were also reduced in the drag test. FII treated slider showed a 45% reduction of AE amplitude and 14% reduction of friction force. FII treatment was confirmed to be effective in improving slider flyability.     

Gelation of telechelic trimethoxysilyl-terminated polyoxazolines

Summary Telechelic bifunctional polyoxazoline (poly(N-acetylethylenimine), PAEI) was prepared by ring-opening polymerization of 2-methyl-2-oxazoline (1) in the presence ofp-(,-dibromo)xylene (2) as an initiator. The terminal propagating ends of this polyoxazoline were reacted with 3-aminopropyltrimethoxysilane (4) to give telechelic trimethoxysilyl-terminated polyoxazoline (5). Gelation of this telechelic polymer was carried out by hydrolysis and condensation of alkoxysilyl groups. By this method, the PAEI gels were obtained in good yields, and their degrees of swelling in the solvent could be controlled successfully by the feed ratios of the initiator to the monomer in the stage of the polymerization of 2-methyl-2-oxazoline. However, the cross-linked products were not stable and gradually dissolved in water. The gels were also swollen inN,N-dimethyl-formamide (DMF). The degrees of swelling of these gels were thus measured in DMF.     

Hydroboration of styryl-terminated polystyrene with bifunctional thexylborane

Summary Hydroboration reaction of the terminal double bond of polystyrene with thexylborane gave the polymer bearing one organoboron unit at the center of the polymer, whose molecular weight was found to be doubled in comparison with the starting polymer. The obtained polymer was subjected to the novel polymer reaction with ,-dichloromethyl methyl ether (DCME) followed by the oxidative treatment. A polymer having one tertiary alcohol unit at the center in the main chain was produced without obvious decrease of the molecular weight.     

Zwitterions of 1-poly(oxyethylene)-2-imidazoline derivatives as anti-electrostatic agent for polyamide fiber

Summary This paper describes a group of anti-electrostatic agents 1 for polyamide fiber(Nylon 6). Agents 1 are calcium imidazolinium-carboxylates having poly(oxyethylene) chain and long alkyl group (C₁₁H₂₃ and C₁₇H₃₅). Eight derivatives of 1 were prepared by a four-step one-pot synthesis shown in Scheme 1. Nylon 6 fibers and films containing some of 1 (1.0 and 2.0 wt%) show improved anti-electrostatic property. The performance of 1 was increased by the increase of the length of poly(oxyethylene) chain.     

Investigation of properties of the TIARA neutron beam facility of importance for calibration applications

Evaluation of the properties for quasi-monoenergetic neutron calibration fields of high energies more than 20 MeV at TIARA is proceeding for development of the field. Among the properties needed for the development as the standard calibration field, we report on measurement of the neutron beam profile using an imaging plate with a polyethylene converter and on estimation of the contribution of scattered neutrons into the irradiation field based on pulse height distribution at various off-beam positions measured using an organic liquid scintillation detector.     

Image‐Based Crack Detection for Real Concrete Surfaces

In this paper, we introduce a novel image‐based approach to detect cracks in concrete surfaces. Crack detection is important for the inspection, diagnosis, and maintenance of concrete structures. However, conventional image‐based approaches cannot achieve precise detection since the image of the concrete surface contains various types of noise due to different causes such as concrete blebs, stain, insufficient contrast, and shading. In order to detect the cracks with high fidelity, we assume that they are composed of thin interconnected textures and propose an image‐based percolation model that extracts a continuous texture by referring to the connectivity of brightness and the shape of the percolated region, depending on the length criterion of the scalable local image processing techniques. Additionally, noise reduction based on the percolation model is proposed. We evaluated the validity of the proposed technique by using precision recall and receiver operating characteristic (ROC) analysis by means of some experiments with actual concrete surface images. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Heat removal verification tests using concrete casks under normal condition

Heat removal tests using two types of full-scale concrete casks were conducted. This paper describes the results under a normal condition of spent fuel storage. In the tests, data on heat removal performance and integrity of cask components were obtained for different storage periods. The change of decay heat of spent fuel was simulated using electric heaters. Reinforced concrete cask (RC cask) and concrete filled steel cask (CFS cask) were the specimen casks. Decay heat at the initial period of storage 60 years of storage, the middle period (20 years of storage), and the final period (40 years of storage) correspond to 22.6 kW, 16 kW and 10 kW, respectively. Quantitative temperature data of the cask components were obtained as compared with their limit temperature. In addition, heat balance data requested for heat removal analyses were obtained.