Damage tolerance of glass mat/epoxy laminates hybridized with flexible resin under static and impact loading

This study deals with the impact property and damage tolerance of matrix hybrid composite laminates with different laminate constitution. The matrix hybrid composite laminates consisted of the laminae with a conventional epoxy resin and the laminae with a flexible epoxy resin modified from the conventional resin to avoid the interlaminar delamination. The impact energy absorption ratio greatly depended on the matrix resin placed at the impact face. The energy absorption was almost constant if the conventional resin was placed at the impact surface layer, while it increased exponentially with the increasing fraction of the flexible resin if the flexible resin was placed at the impact face. The impact energy was absorbed by the damage development and propagation in the laminate with conventional resin laminae as the impacted face, while it was absorbed by both the recoverable deformation of the flexible resin and the damage propagation in the laminate with flexible resin laminae as the impacted face.     

A multiplexer with coupled quarter wave distributed lines in highdielectric ceramics

A multiplexers available several purposes such as for mobile communications, CATV systems and multimedia systems in future, are propped and trially made by authors. This paper present the results the design concept and experimental results. The design principle was based on the theoretical concept proposed by us     

The T cell-directed CC chemokine TARC is a highly specific biological ligand for CC chemokine receptor 4

Thymus and activation-regulated chemokine (TARC) is a recently identified CC chemokine that is expressed constitutively in thymus and transiently in stimulated peripheral blood mononuclear cells. TARC functions as a selective chemoattractant for T cells that express a class of receptors binding TARC with high affinity and specificity. To identify the receptor for TARC, we produced TARC as a fusion protein with secreted alkaline phosphatase (SEAP) and used it for specific binding. By stably transfecting five orphan receptors and five known CC chemokine receptors (CCR1 to -5) into K562 cells, we found that TARC-SEAP bound selectively to cells expressing CCR4. TARC-SEAP also bound to K562 cells stably expressing CCR4 with a high affinity (Kd = 0.5 nM). Only TARC and not five other CC chemokines (MCP-1 (monocyte chemoattractant protein-1), RANTES (regulated upon activation, normal T cells expressed and secreted), MIP-1alpha (macrophage inflammatory protein-1alpha), MIP-1beta, and LARC (liver and activation-regulated chemokine)) competed with TARC-SEAP for binding to CCR4. TARC but not RANTES or MIP-1alpha induced migration and calcium mobilization in 293/EBNA-1 cells stably expressing CCR4. K562 cells stably expressing CCR4 also responded to TARC in a calcium mobilization assay. Northern blot analysis revealed that CCR4 mRNA was expressed strongly in human T cell lines and peripheral blood T cells but not in B cells, natural killer cells, monocytes, or granulocytes. Taken together, TARC is a specific functional ligand for CCR4, and CCR4 is the specific receptor for TARC selectively expressed on T cells.     

The oxidation properties of fourth generation single-crystal nickel-based superalloys

The fourth-generation nickel-based single-crystal superalloys, which contain large amounts of refractory metals for strengthening and platinum group metals for topologically close-packed phase prevention, show excellent high-temperature strength. However, these alloying elements seem to decrease high-temperature oxidation resistance. In this study, nickel-based superalloys with various amounts of tantalum, rhenium, and ruthenium were examined in isothermal and cyclic exposures at 1,100°C to investigate the effect on the oxide growth rate and resistance to scale spallation. Ruthenium and rhenium were found to degrade the oxidation resistance by the vaporization of their oxide. Tantalum-rich oxide in the spinel layer acts to stabilize ruthenium and rhenium oxide in the scale. The addition of hafnium and yttrium is effective in improving the oxidation resistance of ruthenium-containing nickel-based superalloys.     

Influence of third monomer on the crystal phase transition behavior of ethylene-tetrafluoroethylene copolymer

Crystal phase transition between the low- and high-temperature phases has been investigated for ethylene (E)-tetrafluoroethylene (TFE) alternating copolymer (ETFE) containing the third monomeric species by the temperature dependent measurements of wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) and differential scanning calorimetry. Nonafluoro-1-hexene (NFH) and hexafluoropropylene (HFP) were chosen as the third monomers, where they are different in the side-branch length, -(CF₂)₃CF₃ and -CF₃, respectively. In the case of E/TFE/NFH copolymer (ET-C4F9), the crystal phase transition temperature of the original ETFE two-components copolymer was not very much affected by the existence of NFH in the range of NFH content from 0.7 to 3 mol%. Contrarily, the crystal phase transition temperature of E/TFE/HFP copolymer (ET-CF3) was found to decrease drastically with increasing HFP content. The melting temperature and the higher-order structure were also affected sensitively depending on the HFP content. This difference in phase transition behavior between ET-C4F9 and ET-CF3 copolymers is reasonably interpreted as follows: the short side groups (-CF₃) of HFP monomeric unit are included in the crystal lattice of E/TFE chains and the unit cell is expanded gradually with an increment of the HFP content, resulting in the decrease in phase transition point because of easier thermal motion of the chains. On the other hand, the long side groups [-(CF₂)₃CF₃] of NFH monomeric units are excluded out of the crystal lattice and located on the lamellar surfaces or in the amorphous region and do not affect very much the phase transition temperature even when the NFH content is increased. In association with such a change in crystal structure, the long period of stacked lamellar structure was found to decrease remarkably in the case of NFH, whereas it does not change very much for HFP, consistent with the interpretation of the above-mentioned WAXD data.     

Using a GPU to Accelerate Die and Mold Fabrication

The authors present a GPU-based method for generating and verifying cutter paths for numerically controlled milling. A CAM system based on this technology is now employed in production at Mazda Motor Corporation for manufacturing stamping dies. This system can compute cutter paths more than 20 times faster than previous methods     

FDTD analysis of switching characteristics in magnetooptic functional devices using magnetostatic surface waves

Collinear magnetooptic interaction with magnetostatic surface waves (MSSW) can be used for wavelength‐selective switches, wavelength filters, and frequency shifters in wavelength‐division‐multiplexed (WDM) photonic networks and optical processing systems. The switching efficiency can be improved with a multilayer waveguide structure. To investigate the dynamic switching characteristics, the FDTD method was employed. The mode conversion between TE and TM mode was successfully demonstrated with FDTD simulation. The filtering characteristics were also evaluated. The FDTD results were compared with the result from the coupled mode theory, and good agreement was obtained. Switching of an optical pulse was also demonstrated by the FDTD method. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(1): 40–47, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20501