An evaluation method for the mechanical properties of the catheter shaft under cyclic bending was proposed. Cyclic bending tests were conducted to compare mechanical properties of three kinds of specimens. One was the outer layer of the catheter shaft, and the other two were a steel-ribbon catheter shaft and a W-ribbon catheter shaft. Load difference defined by the maximum load of each cycle was used to decide the buckling displacement. Additionally, finite element analysis (FEA) was performed to analyze the deformation behavior of the catheter shaft during a three-point bending test. The load-displacement curves obtained from the FEA showed a good agreement with the envelope of the load-displacement curves in the experiment. It was also revealed from FEA that the deformation behavior of the catheter shaft at the loading point was different from the material of the wire mesh in the catheter shaft. These results also showed that the W-ribbon catheter shaft demonstrated the highest load resistance and the highest buckling displacement. Thus, it was shown that the proposed experimental procedure based on the cyclic bending tests was effective to compare the mechanical properties of various catheter shafts.

As a new broadband-wave absorber material in millimeter waves, the thin rubber sheet containing a porous carbon material “PHYTOPOROUS” made from plant-based ingredients were prepared. We investigated the complex permittivity ε_r*and the reflection loss Γ measured by free-space method using dielectric lenses and incident angle dependence of the reflection loss measured by free-space arch method. The rubber sheet containing PHYTOPOROUS made from soybean hulls showed the reflection loss of more than −20 dB with a bandwidth of 18 GHz at centered frequency of 90 GHz.

The master sintering curve was applied to nanocrystalline CeO₂ powder compact, and the sintering activation energy was determined to be Q = 405 ± 40 kJ mol⁻¹. A classical model was applied to the initial sintering region and gave Q = 360 ± 30 kJ mol⁻¹. The difference is attributed to the effect of the sintering driving-force between in initial and total sintering stages of nanocrystalline CeO₂ particles. The MSC model can be used to predict the total densification of present powder compact under time-temperature excursion. It is conducted that the MSC is an integral work of the sintering concept that is useful for modelling the densification of CeO₂.

Fine ZnO powders have been prepared from plate-like ZnO particles by hydrothermal-treatment in 3 mol/L Zn(NO₃)₂ aqueous solution at 170°C for 7 h (443 K for 25.2 × 10³ s), followed by the heating at 400~700°C for 1 h (673~973 K for 3.6 × 10³ s) in air. They show strong antimicrobial activity in the sunshade; those disinfect many kinds of bacteria even MRSA. The origin of antibacterial activity might be explained in terms of the generation of most powerful reactive oxygen species (ROS) of hydroxyl radical (OH·). As the intensity of chemiluminescence (CL) reflects the amount of ROS, the antibacterial activity has been estimated by measuring the CL emitted from the surface of ZnO in the luminol solution. Both electron spin resonance (ESR) spectroscopy and CL detection were used for identification of ROS. Furthermore, in order to increase the CL values, the ZnO powders have been ball-milled (BM) under the various conditions. It is cleared that the suitable BM conditions, such as BM time and ball size, can improve CL values greatly in comparison with those of ZnO without BM. This effect might be brought by both increasing surface area of ZnO powder and the lattice strain from “Debye effect”.

Human body contains trace inorganic elements that play important roles in the regulation of vital reactions. Biomaterials releasing the trace inorganic elements are suggested to be beneficial for tissue reconstruction remedies. The authors focused on inorganic layered compounds that give drug-releasing system tailored by assembling nanosheet-like crystals of the compounds with inserting ions and macromolecules which promote tissue regeneration. In the present study, calcium silicate hydrate (C-S-H) was selected as the framework, and its preparation conditions via precipitation method were explored. Moreover, the incorporation behaviors of alkylammonium molecules into the C-S-H were evaluated by their simultaneous addition during the method. Agglomerates of nanosheet-like C-S-H were precipitated by introducing calcium nitrate aqueous solution into equimolar concentration of sodium silicate aqueous solution in a controlled manner. By soaking C-S-H into simulated body fluid, which mimicked the inorganic elemental composition of human blood plasma, bone-like apatite was precipitated on its surface. The incorporation of tetrabuthylammonium cations (TBA⁺) were conducted by the addition of its hydroxide into sodium silicate aqueous solution during the preparation. XRD pattern of the sample showed the broadening of a peak, attributed to the interlayer distances in a C-S-H crystal. These results suggested the introduction of TBA⁺ in the C-S-H.

The conveniences afforded by automobiles are accompanied by a number of less salutary consequences—including traffic accidents, air pollution, and traffic congestion—which emerged in the latter half of the twentieth century and which get serious due to rapid motorization in the emerging nations. In order to respond to these problem, the global spread of advanced safety and environmental technologies will be essential. This paper focuses on automated driving systems and discuss their economic features, the government policies needed to encourage their spread, and their social impact.

R₃Al₅O₁₂ (R: rare-earth) ceramics are one of the emitter candidates for thermophotovoltaic (TPV) systems. We conducted a detailed study on the fabrication, the microstructural characterization, and the thermal emissive performance of porous Yb₃Al₅O₁₂ (YbAG) emitters. The emitters were synthesized by solid-state reaction and sintered with various conditions using ball-milling powders, which result in different porosities of the samples. Thermal radiation measurements revealed that the porous ceramics had excellent selectivity regarding emission wavelengths and optimal porosity of sintered bodies for emittance wavelengths selectivity are different according to grain size of powders related to sintered body grain size. Generally, in spite of the narrow-band thermal emissions of rare-earth ions, most ceramics do not present sufficient selectivity because of their transparency in the near infrared range. This paper discusses the mechanism of high selectivity from observations of the microstructures of developed YbAG ceramics.

Multilayered (Li,Na,K)NbO₃ lead-free piezoceramics with Pd inner-electrodes were fabricated by controlling the additive amounts of x mol% MnCO₃ (x = 0.0, 0.5, 1.0, and 2.0) together with other additives. The multilayered samples containing the Mn compound had a markedly increase in electric resistivity from the order of 10⁷ to 10¹¹ Ω·cm at 100°C. Moreover, the normalized electric-field-induced strains for x = 1.0 were over 350 pm/V at 5 kV/mm. The Mn distributions in several multilayered samples were investigated using a scanning electron microscope with an energy dispersive X-ray spectrometry. The segregated Mn phases were observed almost in the vicinity of Pd inner electrodes. In addition, mapping of Mn content for x = 2.0 indicated that segregated Mn phases existed in the ceramic layers. We hypothesize that this complex Mn distribution was related to the results of a continuous driving fatigue test. The multilayered sample with x = 2.0 only maintained a stable state of driving current for fatigue tests over 10⁶ cycles using 0~6 kV/mm triangle wave form at 100°C. This significant electrical reliability was provided by the segregated Mn phases in the ceramic layers.

The substitution of TiO₂ to alumina was examined in low temperature sintered alumina containing a small quantity of a CuO–Nb₂O₅-type additive. The purpose of this research was to both maintain sinterability at a temperature lower than the melting point of Cu, 1357 K, and to improve the dielectric properties, especially the temperature coefficient of resonant frequency (TCF). As a result, we found that both low temperature sinterability at 1308 K and TCF zeroing were achieved simultaneously. Analyses by XRD and TEM–EDS revealed that substituted TiO₂ does not react with Al₂O₃ and does not produce Al₂TiO₅ which inhibits TCF zeroing at the firing temperature of this study; hence, this is the cause of achieving TCF zeroing. The developed material fired at 1308 K in an air atmosphere with the composition of TiO₂ substitution amount of 12 mol% showed great properties: a relative density of approximately 98%, a relative permittivity (ε_r) of 13.6, a product of quality factor and resonant frequency (Q·f) of 28000 GHz, a TCF of ±0 ppm/K, and a high thermal conductivity of 20 W/mK. Further, similar properties were obtained for samples fired at 1323 K in a nitrogen atmosphere.