Proton conduction at the surface of Y-doped BaCeO3 and its application to an air/fuel sensor

25 mol% Y³⁺-doped BaCeO₃ (BCY25) showed an extremely low activation energy of 0.3 eV for proton conduction at the surface. The resulting overall conductivity at the surface reached 8.24 × 10^–3 S cm^–1 at 400°C, which was 3, 8, and 28 times higher than those in the bulk of BCY25, 20 mol% Sm³⁺-doped ceria, and 8 mol% yttria-stabilized zirconia, respectively. Such fast proton conduction enabled an air/fuel (A/F ) sensor using BCY25 as the solid electrolyte to work above 150°C for H₂ and above 250°C for C₂H₄.     

Deformation behaviour of elastic-plastic tubes under external pressure and axial load

A constitutive equation taking into account corner formation on the yield surface and the Bauschinger effect is developed. The behaviour of circular long tubes subjected to external pressure and axial load under plane strain and generalized plane-strain conditions are analyzed in conjunction with the proposed constitutive equation. The influence of axial load, the Bauschinger effect and corner formation, including the corner angle, and the mobility of the corner axis to the direction of stress history upon such global deformation behaviour as maximum pressure, pressure vs displacement relation and axial strain, are clarified. With regard to local deformation, these effects on the strain rate and strain localization, surface unevenness and shear band formation from the highly strained internal surface are investigated.     

A Technique to Eliminate Redundant Inter-Processor Communication on Parallelizing Compiler TINPAR

Optimizing inter-processor (PE) communication is crucial for parallelizing compilers for message-passing parallel machines to achieve high performance. In this paper, we propose a technique to eliminate redundant inter-PE messages. This technique utilizes data-flow analysis to find a definition point that corresponds to a use point where the definition and the use occur in different PEs. If several read accesses occurred in the same PE use the data defined at the same definition point in another PE, redundant inter-PE messages are eliminated as follows: only one inter-PE communication is performed for the earliest read access and the previously received data are used for the following read. In order to guarantee the consistency of the data, a valid flag and a sent flag are provided for each chunk of received data. The control of these flags is equivalent to the coherence control by the self invalidation on a compiler aided cache coherence scheme.     

Prediction of ethylene content in melt-state random and block polypropylene by near-infrared spectroscopy and chemometrics: comparison of a new calibration transfer method with a slope/bias correction method

This paper reports the prediction of the ethylene content (C2 content) in random polypropylene (RPP) and block polypropylene (BPP) in the melt state by near-infrared (NIR) spectroscopy and chemometrics. NIR spectra of RPP and BPP in the melt states were measured by a Fourier transform near-infrared (FT-NIR) on-line monitoring system. The NIR spectra of RPP and BPP were compared. Partial least-squares (PLS) regression calibration models predicting the ethylene (C2) content that were developed by using each RPP or BPP spectra set separately yielded good results (SECV (standard error of cross validation): RPP, 0.16%; BPP, 0.31%; correlation coefficient: RPP, 0.998; BPP, 0.996). We also built a common PLS calibration model by using both the RPP and the BPP spectra set. The results showed that the common calibration model has larger SECV values than the models based on the RPP or the BPP spectra sets individually and is not practical for the prediction of the C2 content. We further investigated whether a calibration model developed by using the BPP spectra set can predict the C2 contents in the RPP sample set. If this is possible, it can save a significant amount of work and cost. The results showed that the use of the BPP model for the RPP sample set is difficult, and vice versa, because there are some differences in the molar absorption coefficients between the RPP and BPP spectra. To solve this problem, a transfer method from one sample spectra (BPP) set to the other spectra (RPP) set was studied. A difference spectrum between an RPP spectrum and a BPP spectrum was used to transfer from the BPP calibration set to the RPP calibration set. The prediction result (SEP (standard error of prediction), 0.23%, correlation coefficient, 0.994) of RPP samples by the transferred calibration set and model showed that it is possible to transfer from the BPP calibration set to the RPP calibration set. We also studied the transfer from the RPP calibration set (the range of C2 content: 0-4.3%) to the BPP calibration set. The prediction result of C2 content (the range of C2 contents: 0-7.7%) in BPP by use of the calibration model based on the transferred BPP spectra from the RPP spectra showed that the transfer method is only effective for the interpolation of the C2 content range by the nonlinear change in the peak intensities with the C2 content.     

Rayleigh waves in magneto-thermoelastic solids with thermal relaxation

Following a linear theory of magneto-thermo-elasticity with thermal relaxation, the propagation of Rayleigh waves in a semi-infinite body permeated by an uniform magnetostatic field parallel to the boundary surface is investigated. It is assumed that the elastic medium under consideration is a homogeneous, isotropic, electrically and thermally conducting one. The roots of the frequency equation are calculated numerically. The approximate solution for small thermoelastic and magnetoelastic coupling is obtained and compared with the exact solution.     

Back‐channel‐etched thin‐film transistor using c‐axis‐aligned crystal In–Ga–Zn oxide

Our crystalline In–Ga–Zn oxide (IGZO) thin film has a c‐axis‐aligned crystal (CAAC) structure and maintains crystallinity even on an amorphous base layer. Although the crystal has c‐axis alignment, its a‐axis and b‐axis have random arrangement; moreover, a clear grain boundary is not observed. We fabricated a back‐channel‐etched thin‐film transistor (TFT) using the CAAC‐IGZO film. Using the CAAC‐IGZO film, more stable TFT characteristics, even with a short channel length, can be obtained, and the instability of the back channel, which is one of the biggest problems of IGZO TFTs, is solved. As a result, we improved the process of manufacturing back‐channel‐etched TFTs.     

Slc25a39 and Slc25a40 Expression in Mice with Bile Duct Ligation or Lipopolysaccharide Treatment

SLC25A39/40, involved in mitochondrial GSH (mGSH) import from the cytoplasm, is essential for protection against oxidative stress and mitochondrial dysfunction. We examined the effects of cholestasis, through bile duct ligation (BDL) and lipopolysaccharide (LPS)-induced inflammation in mice, on Slc25a39/40 expression. Additionally, we used human clear cell renal carcinoma (KMRC-1) cells to elucidate the mechanism of regulation of SLC25A39/40 expression in the kidneys after LPS treatment. BDL resulted in a decrease in Slc25a39 mRNA in the liver and a decrease in Slc25a39/40 mRNA and protein in the kidneys. Consequently, there was a significant decrease in mGSH levels in the kidneys of BDL mice compared with those in sham mice. LPS treatment resulted in increased Slc25a40 expression in the kidneys. In KMRC-1 cells, the combination treatment of LPS-RS or FPS-ZM1 with LPS suppressed the LPS-induced increase in SLC25A40, suggesting that SLC25A40 expression could be regulated by the signaling pathway via toll-like receptor 4 and the receptor for advanced glycation end products, respectively. Our findings contribute to understanding the role of mGSH in the maintenance of the mitochondrial redox state. To the best of our knowledge, this is the first study that demonstrates the changes in Slc25a39/40 expression in mice with cholestasis-associated renal injury and LPS-induced inflammation.     

Spectral hole burning and carrier-heating effect on the transientoptical nonlinearity of highly carrier-injected semiconductors

An improved density-matrix theory is developed that can treat both spectral hole burning and carrier heating self consistently. Various intraband and interband relaxation terms characterized by different relaxation times and quasi-equilibrium distributions are introduced into the density-matrix equations within a relaxation-time approximation. Conservation of total number and energy densities of carrier systems in each band is considered to determine the quasi-equilibrium distributions. Formalism is applied to the calculation of the transient optical nonlinearity of highly carrier-injected semiconductors. Spectral hole burning and carrier-heating effects on the spectral and temporal characteristics are then clarified. In particular, the significant four-wave-mixing effect due to carrier heating is pointed out. An experiment that can be used to directly prove the existence of the carrier-heating effects on gain nonlinearity is also proposed     

High performance double-doped InAlAs/InGaAs/InP heterojunction FET with potential for millimetre-wave power applications

Lattice matched InAlAs/InGaAs/InP heterojunction field-effect transistors (HJFETs), which have carrier supplying layers on and beneath the undoped InGaAs channel layer, have been successfully fabricated. A selective recess of the InGaAs channel edge at a mesa sidewall together with the use of a wide recess gate structure leads to a 5.7 V gate-drain breakdown voltage without kink effects. The fabricated HJFET with a 0.15*100 mu m/sup 2/ T-shaped gate exhibits a 700 mA/mm maximum drain current, a voltage gain of 14, and a 345 GHz maximum frequency of oscillation.<>     

Domain–Specific High–Level Modeling and Synthesis for ATM Switch Prototyping

ATM switch, the core technology of an ATM networking system, is one of the major products in Fujitsu telecommunication business. However, current gate–level design methodology can no longer satisfy its stringent time–to–market requirement. It becomes necessary to exploit high–level methodology to specify and synthesize the design at an abstraction level higher than logic gates. This paper presents our prototyping experience on domain–specific high–level modeling and synthesis for Fujitsu ATM switch design. We propose a high–level design methodology using VHDL, where ATM switch architectural features are considered during behavior modeling, and a high–level synthesis compiler, MEBS, is prototyped to synthesize the behavior model down to a gate–level implementation. Since the specific ATM switch architecture is incorporated into both modeling and synthesis phases, a high–quality design is efficiently derived. The synthesis results shows that given the design constraints, the proposed high–level design methodology can produce a gate–level implementation by MEBS with about 15 percent area reduction in shorter design cycle when compared with manual design.