Physicochemical properties of monosodium glutamate-compounded tapioca starch exceeds those of simple heat-moisture treated starch

Monosodium glutamate (GluNa)-compounded starch was prepared by heat-moisture treating a mixture of tapioca starch and GluNa. GluNa-compounded starch exhibited a higher gelatinization temperature and reduced swelling and solubility, essentially lower hardness of the granule center, and paste viscosity than those of the heat-moisture treated tapioca starch and the untreated starch. However, its appearance, unit chain length distribution, and α-amylase digestibility were similar to those of the heat-moisture treated tapioca. It is thus concluded that GluNa compounding is useful for providing a unique type of starch that possesses a less swollen and viscous texture than that produced with simple heat-moisture treatment.     

Present Status of the Nd:YAG Thomson Scattering System Development for Time Evolution Measurement of Plasma Profile on Heliotron J

A new high repetition rate Nd:YAG Thomson scattering system is developed for the Heliotron J helical device.A main purpose of installing the new system is the temporal evolution measurement of a plasma profile for improved confinement physics such as the edge transport barrier (H-mode) or the internal transport barrier of the helical plasma.The system has 25 spatial points with ～10mm resolution.Two high repetition Nd:YAG lasers (>550mJ@ 50Hz) realize the measurement of the time evolution of the plasma profile with ～10ms time intervals.Scattered light is collected by a large concave mirror (D=800 mm,f/2.25) with a solid angle of ～100 mstr and transferred to interference filter polychromators by optical fiber bundles in a staircase form.The signal is amplified by newly designed fast preamplifiers with DC and AC output,which reduces the low frequency background noise.The signals are digitized with a multi-event QDC,fast gated integrators.The data acquisition is performed by a VME-based system operated by the CINOS.     

Formation Mechanism of Type IV Failure in High Cr Ferritic Heat-Resistant Steel-Welded Joint

The mechanism of type IV failure has been investigated by using a conventional 9Cr ferritic heat-resistant steel Gr.92. In order to clarify the main cause of type IV failure, different heat treatments were performed on the base metal in order to change the prior austenite grain (PAG) size and precipitate distribution after applying the heat-affected zone (HAZ) simulated thermal cycle at the peak temperature of around A _c3 (A _c3 HAZ thermal cycle) and postweld heat treatment (PWHT). The microstructural evolution during the A _c3 HAZ thermal cycle and PWHT was investigated by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), electron probe microanalysis (EPMA), and transmission electron microscope (TEM). It was found that M₂₃C₆ carbides were scarcely precipitated at the newly formed fine PAG, block, and lath boundaries in A _c3 HAZ-simulated Gr.92, because the carbide forming elements such as Cr and C were segregated at the former PAG and block boundaries of the base metal. On the other hand, if all the boundaries were covered by sufficient M₂₃C₆ carbides by homogenization of the alloying elements prior to applying the HAZ thermal cycle, the creep strength was much improved even if the fine PAG was formed. From these results, it is concluded that fine-grained microstructure cannot account for the occurrence of type IV failure, and it only has a small effect during long-term creep. The most important factor is the precipitate formation behavior at various boundaries. Without sufficient boundary strengthening by precipitates, the microstructure of A _c3 HAZ undergoes severe changes even during PWHT and causes premature failure during creep.     

Melt crystallization of poly(ethylene terephthalate): Comparing addition of graphene vs. carbon nanotubes

Poly(ethylene terephthalate) (PET)-based nanocomposites with graphene or multi-wall carbon nanotubes (MWCNT) were prepared by melt mixing. Aspect ratio, A_f, and interparticle distance, λ, of graphene in the nanocomposites were obtained from melt rheology and transmission electron microscopy respectively. λ of PET/graphene nanocomposites was much smaller than λ in PET/MWCNT. For PET/graphene with highest A_f, λ became <1 μm at more than 0.5 wt% graphene. Non-isothermal crystallization behavior from the melt was investigated by differential scanning calorimetry. The crystallization temperatures suggest that the nucleation effect of graphene was stronger than that of MWCNT. The half crystallization time of PET/graphene became longer than PET/MWCNT with increasing graphene loading, suggesting that confinement by graphene suppressed the crystal growth rate. XRD analysis indicated that smaller crystals formed in PET/graphene than in PET/MWCNT. From Raman spectroscopy, the π–π interaction between PET and graphene was stronger than that between PET and MWCNT. This stronger interaction in PET/graphene appears to result in formation of crystals with higher perfection.     

Moving pick‐up‐type contactless power transfer systems and their efficiency using series and parallel resonant capacitors

The equivalent circuit, the efficiency, and the important characteristics of moving pick‐up type contactless power transfer systems are described. If the primary series capacitor and the secondary parallel capacitors are chosen correctly and the winding resistances are ignored, the equivalent circuit of the transformer with these capacitors becomes the same as an ideal transformer at the resonant frequency. This simple approximation helps to understand the phenomena occurring with load changes. Because the circuit analysis becomes simple, the approximate value of the power transfer efficiency can be derived. This paper describes the determination of the capacitor values, the derivation of the equivalent circuit and the efficiency, and test results. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(2): 47–54, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20970     

Phase equilibria in the Co-rich Co-Al-W-Ti quaternary system

We determined phase equilibria in the Co-rich Co-Al-W-Ti quaternary system at a temperature range between 900 °C and 1200 °C with a close attention to the thermodynamic stability of the γ′-Co₃(Al, W, Ti) (L1₂) phase, based on micro-structure observation and electron microprobe analysis on bulk alloy samples heat-treated for periods up to 2000 h. In the quaternary system the single phase field of γ′ extends from the Co-Ti binary edge to a composition of Co-5Al-8.5W-8Ti (in at.%) at 900 °C. At the tip of the single phase field, the γ′ phase is in equilibrium with the γ-Co (A1), Co₂AlTi (L2₁) and Co₃W (D0₁₉) phases. The constructed vertical section of phase diagram between Co-9.4Al-9.6W and Co-16.5Ti indicates that there is a narrow composition range around Co-4.5Al-5.4W-7.5Ti in which the γ single phase field exists at high temperatures above 1200 °C and two-phase of γ+γ′ is thermodynamically stable at low temperatures below 1100 °C.     

Influence of phosphate species on green rust I transformation and local structure and morphology of γ-FeOOH

To clarify the role of phosphate in the formation of corrosion products, the transformation of GRI(Cl⁻) with the addition of phosphate was characterized through XRD, TEM, and solution analysis. Electrochemical analysis showed that the transformation of GRI(Cl⁻) was delayed and the size of the final products, i.e., γ-FeOOH was reduced in the phosphate added case. X-ray absorption spectroscopy indicated that the neighboring Fe–Fe coordination number of FeO₆ octahedral unit in γ-FeOOH was decreased. These effects of phosphate are attributed to its adsorption on GRI(Cl⁻) and nucleated γ-FeOOH that prevented particle growth during oxidation process.     

Photocatalytic hydrogenation of acetophenone derivatives and diaryl ketones on polycrystalline titanium dioxide

In the absence of molecular oxygen, various aromatic ketones such as acetophenone derivatives and diaryl ketones were photocatalytically hydrogenated on polycrystalline titanium dioxide (Degussa P25) under UV light irradiation (> 340 nm). The desired secondary alcohols were obtained with excellent chemical efficiency (almost 100% yields for 10 examples) by choosing ethanol as a sacrificial hole scavenger, which was oxidized into acetaldehyde.     

A Computational Study of Thrust Vectoring Control Using Dual Throat Nozzle

Dual throat nozzle （DTN） is fast becoming a popular technique for thrust vectoring. The DTN is designed with two throats, an upstream minimum and a downstream minimum at the nozzle exit, with a cavity in between the upstream throat and exit. In the present study, a computational work has been carried out to analyze the performance of a dual throat nozzle at various mass flow rates of secondary flow and nozzle pressure ratios （NPR）. Two-dimensional, steady, compressible Navier-Stokes equations were solved using a fully implicit finite volume scheme. The present computational results were validated with available experimental data. Based on the present results, the control effectiveness of thrust-vectoring is discussed in terms of the thrust coefficient and the coefficient of discharge.