Characterization of the formation of α1plates from the β3phase in a Cu- Zn- Au alloy

The crystal structures and ordering structures of α₁ bainite plates and β₃ parent phase have been studied by means of electron microscopy in a Cu-40Zn-12Au (at. pct) alloy. The ordering transitions take place in the high-temperature β phase, and a stable L21 structure is reached even after direct quenching. The next-nearest-neighbor antiphase domains (NNNAPDs) are about 40 nm in size and have an island morphology surrounded by some nearly disordered regions. Wide isolated a, plates are present in 473 K aged microstructures, but at lower aging temperatures, thinner bainite plates tend to form in some coordinate modes. Reoriented second-stage thickening and stress-induced local thickening of thin a, plates have also been observed. Microanalysis of solute concentrations in thin bainite plates and in the matrix has shown the involvement of solute diffusion not only in the thickening process but also in the nucleating of the plate. Based on the results, an ordering facilitated shear mechanism is proposed for the a, bainite transformation, which can successfully explain its characteristics.     

Direct Hydroxylation of Methyl Benzoate to Methyl Salicylate by Using New Pd Membrane Reactor

The direct hydroxylation of methyl benzoate was carried out using a newly developed Pd membrane reactor in which the active oxygen species is formed on the surface of Pd by the reaction between oxygen gas and the active hydrogen atoms that permeate through the Pd membrane from the opposite side. By using this Pd membrane reactor system, methyl salicylate showed a 4.7% yield at 423 K. The reaction mechanism was clarified based on the distribution of by-products.     

Fracture toughness and fatigue crack propagation in high strength steel from room temperature to −180°c

Fracture toughness under tensile test and fatigue test on high strength steel at temperature ranging from room temperature to ?180°C were experimentally studied. The value of fracture toughness under fatigue test is considerably tower than that obtained under tensile test.Within the range from room temperature to ?100°C the following results were obtained: the power coefficient δ of the fatigue crack propagation rate $\text{[(dc)/(dN)] = AΔK}{}^5$ is related with [(1)/($\text{T}$)] as: $\text{δ = b}{}_1\text{+ [(a}{}_1\text{)/(kT)]}$. $\text{[(dc)/(dN)]}$ shows Arrhenius type, and, however, different equation from usual stress dependent rate process equation. The trend is in good agreement with the dislocation dynamics theory of fatigue crack propagation.     

High-birefringence polarizing fiber with flat cladding

This paper presents the theoretical and experimental investigations on polarization characteristics of PANDA fiber with flat cladding. It is theoretically shown that the modal birefringence in the flat-clad fiber is almost the same as that in the circular-clad fiber. The flat-clad PANDA fiber has been fabricated by grinding off the preform cladding on the opposite faces and then drawing with a low furnace temperature. The modal birefringence of the fiber isB = 5.9 times 10^{-4}and the separation of the bending loss edges for the two polarization modes isDeltaupsilon = 0.51in the normalized frequency. The polarizing region can be tuned from 1.3 to 1.56 μm by varying the fiber-bending diameter from 3.5 to 4.5 cm. A 1.5-m length of polarizing fiber exhibits extinction ratios of 44.9 and 44.4 dB with insertion losses for the guided mode of 0.25 and 0.41 dB at 1.3 and 1.56 μm, respectively.     

Passive emission colorimetric sensor (PECS) for measuring emission rates of formaldehyde based on an enzymatic reaction and reflectance photometry

A coin-sized passive emission colorimetric sensor (PECS) based on an enzymatic reaction and a portable reflectance photometry device were developed to determine the emission rates of formaldehyde from building materials and other materials found indoors in only 30 minutes on-site. The color change of the PECS linearly correlated to the concentration of formaldehyde aqueous solutions up to 28 microg/mL. The correlation between the emission rates measured by using the PECS and those measured by using a desiccator method or by using a chamber method was fitted with a linear function and a power function, and the determination coefficients were more than 0.98. The reproducible results indicate that the emission rates could be obtained with the correlation equations from the data measured by using the PECS and the portable reflectance photometry device. Limits of detection (LODs) were 0.051 mg/L for the desiccator method and 3.1 microg/m2/h for the chamber method. Thus, it was confirmed that the emission rates of formaldehyde from the building materials classified as F four-star (< 0.3 mg/L (desiccator method) or < 5.0 microg/m2/h (chamber method)), based on Japanese Industrial Standards (JIS), could be measured with the PECS. The measurement with PECS was confirmed to be precise (RSD < 10%). Other chemicals emitted from indoor materials, such as methanol, ethanol, acetone, toluene, and xylene, interfered little with the measurement of formaldehyde emission rates by using the PECS.     

Detection of nitric oxide (NO) in marine phytoplankters

In raphydophyte cell suspensions such as those of Chattonella marina, C. ovata and Heterosigma akashiwo, a gradual increase in NO-specific fluorescence intensity was observed, and the increase in the fluorescence intensity of each of these phytoplankters was completely inhibited in the presence of carboxy-PTIO, a specific NO scavenger. However, no such significant changes were observed in the case of other phytoplankter species.     

Survey of epoxidized soybean oil in cap sealing for bottled foods

Epoxidized soybean oil (ESBO) was surveyed in the 103 samples of cap sealing for bottled foods on the Japanese market. Most of the sealings were made of polyvinyl chloride, while a few were made of polyethylene or acrylic resin. All the sealings contained ESBO in the range of 0.006-42.4%. Sealings for baby food, jam, etc. contained higher levels of ESBO, though those for beverages contained lower levels. Sealings in lug caps and press-on twist caps contained higher levels of ESBO, though that in pilfer-proof caps contained lower levels. Some sealings in screw caps and lug caps also contained other plasticizers, for example, di-2-ethylhexyl phthalate and diisononyl phthalate, and their ESBO contents were 1/10 of those in sealings containing only ESBO. In this survey, ESBO was the most common plasticizer in cap sealing resin for bottled foods on the Japanese market.     

Analysis of constituents in urushi wax, a natural food additive

Urushi wax is a natural gum base used as a food additive. In order to evaluate the quality of urushi wax as a food additive and to obtain information useful for setting official standards, we investigated the constituents and their concentrations in urushi wax, using the same sample as scheduled for toxicity testing. After methanolysis of urushi wax, the composition of fatty acids was analyzed by GC/MS. The results indicated that the main fatty acids were palmitic acid, oleic acid and stearic acid. LC/MS analysis of urushi wax provided molecular-related ions of the main constituents. The main constituents were identified as triglycerides, namely glyceryl tripalmitate (30.7%), glyceryl dipalmitate monooleate (21.2%), glyceryl dioleate monopalmitate (2.1%), glyceryl monooleate monopalmitate monostearate (2.6%), glyceryl dipalmitate monostearate (5.6%), glyceryl distearate monopalmitate (1.4%). Glyceryl dipalmitate monooleate isomers differing in the binding sites of each constituent fatty acid could be separately determined by LC/MS/MS.     

Determination of epoxidized soybean oil and linseed oil in wrapping film and cap sealing

A determination method was developed for epoxidized soybean oil (ESBO) and epoxidized linseed oil (ELO), which are used as plasticizers and/or stabilizers, in wrapping film and cap sealings. The ESBO method reported by Castle et al. was improved. Samples were extracted with acetone-hexane (3: 7), transmethylated under alkaline conditions, then derivatized to the 1,3-dioxolanes and analyzed by GC/MS. The recoveries of spiked ESBO and ELO were between 92.6% and 104.4%. The determination limits were 0.01 mg/g for ESBO and 0.02 mg/g for ELO in the wrapping film, and 0.04 mg/g and 0.08 mg/g in the cap sealing. ESBO and ELO were surveyed in 10 samples each of wrapping film and cap sealings currently available on the Japanese market. ESBO was found at 34.7-82.8 mg/g in polyvinyl chloride (PVC) wrapping films and at 5.47-399 mg/g in cap sealings. ELO was detected at 8.6-11.4 mg/g in polyvinylidene chloride (PVDC) wrapping films, and at 46.4 mg/g in a PVC wrapping film.