Vector unit architecture for emotion synthesis

Two vector units embedded in the emotion engine chip support high-quality 3D graphics, emotion synthesis, and 300-MHz, 5.5-GFLOPS operation for the recently introduced PlayStation2 game entertainment system     

A comparison of sintering techniques using different particle sized β-SiAlON powders

In the present study sintering behavior and mechanical properties of β-SiAlON ceramics were investigated using different sintering techniques (gas pressured sintering (GPS), pressureless sintering and spark plasma sintering (SPS)) and different particle sized powders (with D_BET 216 and 130 nm). After sintering of the microstructure and phase characterization were carried out using a scanning electron microscope (SEM) and the X-ray diffraction (XRD) method, respectively. All the samples, prepared using fine powder, were sintered at lower temperatures than samples prepared by conventional powder, by two sintering techniques (GPS and pressureless). Additionally, the results showed that cooling rates had an important effect on the formation and the amount of intermediate phase in the sample. As a result, it was shown that the particle size of starting raw materials, the amount of additive, the sintering temperature and the technique had a significant effect on the microstructure and mechanical properties of the SiAlON samples.     

Seasonal Variations in the Fatty Acid Composition of Phospholipid and Triacylglycerol in Gonad and Liver of Mastacembelus simack

The seasonal effects on the fatty acid composition of triacylglycerol (TG) and phospholipid (PL) in the gonad and liver of Mastacembelus simack were determined using the gas chromatographic method. The most abundant fatty acids in the investigated seasons and tissues were palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n‐9), palmitoleic acid (C16:1n‐7), arachidonic acid (C20:4n‐6), eicosapentaenoic acid (C20:5n‐3), and docosahexaenoic acid (C22:6n‐3). The distribution proportions of ∑SFA (saturated fatty acids), ∑MUFA (monounsaturated fatty acids) and ∑PUFA (polyunsaturated fatty acids) were found to be different among PL and TG fractions in all seasons. The total lipid content of gonad and liver were 1.32 (November)–4.90 % (September) and 1.32 (September)–3.94 % (January), respectively. It was shown that the total lipid and fatty acid compositions in the gonad and liver of fish were significantly influenced by seasons.     

Characterization of polycrystalline silicon wafers for solar cells sliced with novel fixed‐abrasive wire

For slicing crystalline silicon ingots, we have developed a novel fixed‐abrasive wire where diamond grit is fixed onto a bare wire by resin bonding. The properties of the wafers sliced using a multi‐wire saw with the fixed‐abrasive wire have been investigated. When compared with the wafers sliced with the loose‐abrasive wire, the slicing speed is improved by approximately 2.5‐fold and the thicknesses of saw‐damage layers are reduced by more than a factor of two. Polycrystalline silicon solar cells have been fabricated for the first time utilizing the wafers sliced with the fixed‐abrasive wire, and the cells with the saw‐damage etching depth of 7 µm have shown photovoltaic properties comparable to those prepared using the wafers sliced with the loose‐abrasive wire and subsequently etched to remove the damage layers up to 15 µm. It has been clarified that wafer slicing using the fixed‐abrasive wire is promising as a next‐generation slicing technique for fabrication of solar cells, particularly thin silicon cells where the wafer thicknesses approach or become less than 150 µm. Copyright © 2010 John Wiley & Sons, Ltd.     

Effect of the processing on the production of cordierite–mullite composite

In this study, effect of process on the production of cordierite–mullite composite was studied. For this reason two different processing methods were used in the production of cordierite–mullite composites. In first process, in situ cordierite–mullite composites were produced from cordierite and mullite layers which were formed by using aqueous tape casting method. In second one, composite was produced by addition of pre-produced mullite powders (in different weight percents, 0–30) into cordierite starting powders. The results show that the addition of pre-sintered mullite powders to the cordierite slip has more effect on densification behavior and mechanical properties of composites than layered production method.     

Effects of low-temperature ozone annealing on operation characteristics of amorphous In-Ga-Zn-O thin-film transistors

Effects of low-temperature annealing were examined for amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs). In a previous study, we reported that O₂ annealing is effective to improve performances of a-IGZO TFTs when annealed at ≥ 300 °C, but causes large negative threshold voltage shift when annealed at ≤ 200 °C. Here, we examined effects of ozone (O₃) annealing on physical properties and TFT characteristics of a-IGZO in comparison with conventional O₂ annealing. We found little differences in chemical composition, band gap and photoemission spectra between the O₂ and the O₃ annealed films. On the other hand, free electron density was suppressed well by the O₃ annealing even at low temperatures ≤ 200 °C. Moreover, even at 150 °C, the TFTs characteristics were improved to the subthreshold voltage swing of 217 mV/decade, the saturation mobility of ~ 11.4 cm²(Vs)^− 1 and the threshold voltage of 0.1 V by the O₃ annealing. It was also found that the effects of the O₃ annealing is more effective for thicker channel TFTs, which would be due to stronger oxidation power and the larger diffusion constant of oxygen atoms produced from O₃ molecules than those of O₂. These results substantiate that the O₃ annealing is more effective to improve TFT characteristics in particular for low-temperature processes at ≤ 200 °C.     

Voltage fluctuation compensator for Shinkansen

In AC electric railways, three‐phase voltage is changed into the single‐phase circuit of two circuits with the Scott‐connected transformer. If unbalancing of the load between single‐phase circuits becomes large, voltage fluctuation becomes large on the three‐phase side. Railway static power conditioner (RPC) was developed for the purpose of controlling voltage fluctuation on the three‐phase side. An RPC is comprised of a pair of self‐commutated PWM inverters. These inverters connect the main phase and teaser feeding buses, coupled with a DC side capacitor such as a back‐to‐back (BTB) converter. In this way, the two self‐commutated inverters can act as a static var compensator (SVC) to compensate for the reactive power and as an active power accommodator from one feeding bus to another. 20 MVA/60 kV RPCs started commercial operation in 2002 at each two substations on the newly extended Tohoku Shinkansen for compensating voltage fluctuation on the three‐phase side caused by traction loads, absorbing harmonic current. The results of operational testing indicate that an RPC can accommodate single‐phase loads such as those of PWM‐controlled Shinkansen and thyristor phase‐controlled Shinkansen, and handle the exciting rush current of transformers, as well as compensate for harmonics successfully. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(4): 25–34, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20397     

A study of generator system selection for large wind turbine generator system

This paper focuses on selection of wind turbine generation systems that include generators, converters, and gears. We study three systems: a permanent magnet generator (PMG) system, a doubly‐fed generator (DFG) system, and a synchronous generator (SYG) system in terms of the system efficiencies and running costs. The system efficiencies and running costs are calculated by considering the relationship between wind power and wind conditions. According to these results, the one‐step gear PMG system is the best choice for a large wind turbine system. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 51–57, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20506     

S-allylcysteine attenuates oxidative stress in endothelial cells

Oxidation of low-density lipoprotein (LDL) has been recognized as playing an important role in the initiation and progression of atherosclerosis. We recently reported that S-allylcysteine (SAC), one of the major compounds in the aged garlic extract (AGE), inhibited LDL oxidation and minimized oxidized LDL-induced cell injury. In this study, the antioxidant effects of SAC were further determined using several in vitro assay systems. Pulmonary artery endothelial cells (PAECs) were preincubated with SAC at 37°C and 5% CO₂ for 24 hr, washed, and then exposed to 0.1 mg/ml oxidized LDL for 24 hr. Lactate dehydrogenase (LDH) release, as an index of membrane injury, and intracellular glutathione (GSH) levels were determined. Oxidized LDL caused an increase of LDH release and depletion of GSH. Pretreatment with SAC prevented these changes. Peroxides were measured directly in 24-well plates using a fluorometric assay. SAC dose-dependently inhibited oxidized LDL-induced release of peroxides in PAEC. In a cell-free system, SAC was shown to scavenge hydrogen peroxide. Our data demonstrate that SAC can protect endothelial cells from oxidized LDL-induced injury by removing peroxides and preventing the intracellular GSH depletion and suggest that this compound may be useful for the prevention of atherosclerosis.     

Analysis of permanent-magnet machine for sensorless control based on high-frequency signal injection

This paper presents the analysis of a surface-mounted permanent-magnet (SMPM) machine for the sensorless control scheme based on the high-frequency fluctuating voltage signal injection method. A simplified high-frequency model of an SMPM machine in the estimated rotor reference frame is developed and a sensorless rotor position and speed estimation algorithm is described. To support this, the high-frequency impedances of an SMPM machine are analyzed by finite-element analysis (FEA) and compared with measurement results using a pulsewidth-modulation (PWM) inverter system under various injection conditions. The results of the FEA and measurements are coincident with each other with some errors due to the nonlinear behavior of the PWM inverter and the SMPM machine. The analysis results give physical insights into selecting the injection conditions for sensorless operation of the SMPM machine even though adjustments considering nonlinear behaviors of PWM inverters are required in the actual operation for the desired performance. The experimental results of speed and position control using a commercial SMPM machine are presented based on the analysis of the SMPM machine for the sensorless control algorithm.