Effect of CaCl2 hydrothermal treatment on the bone bond strength and osteoconductivity of Ti–0.5Pt and Ti–6Al–4V–0.5Pt alloy implants

To achieve osteoconductivity, Ti–0.5Pt and Ti–6Al–4V–0.5Pt alloys were hydrothermally treated at 200°C in 10 mmol/l CaCl₂ aqueous solution for 24 h (HT-treatment). We conducted histological investigations of the HT-treated materials by using Wistar strain rats (SD rats) to evaluate the usefulness of the treatment. To measure the bone bond strength, the specimens were implanted in the tibia of SD rats, and a pull-out test was conducted. From the early postoperative stages, direct bone contact was obtained for the HT-treated implants. Within 1–4 weeks of implantation, the bone contact ratios and bone bond strengths of the HT-treated implants were higher than those of the non-treated implants. The Ti–0.5Pt and Ti–6Al–4V–0.5Pt alloys with HT-treatment showed the potential to develop a new implant with a high bone bond strength and rapid osteoconduction.     

放射性廃棄物量を低減するための低放射化材料の開発(英文)

原子炉などの施設が寿命を迎えると莫大な量の放射性廃棄物が発生する.であるのであらかじめ設計段階から廃棄物が出ないようなプランが必要である.その方法は(1)セメント·骨材·鉄筋などのマテリアルデータベース、(2)データベースに基いた低放射化セメント·鉄筋などの製造·採用、(3)原子炉遮蔽壁などへの施工·解体の最適化から生まれる.低放射化骨材·セメント·混和材量により低放射化コンクリートは可能になる.それらを適切に組み合わせることにより、従来型の原子炉壁使用コンクリートの1/10,1/20,1/30,...,1/1000,1/3000,1/10 000の低放射化が計れる.1/10,の低放射化とは仮想安山岩を骨材とした普通コンクリートをベースに計算される.そしてこれらは改良型BWRあるいはPWR原子炉用コンクリートに用いた場合、解体時のクリアランスレベル以下に廃棄物をすることが期待される.低放射化コンクリートを製造するために肝心なことは、放射化しやすい核種を含まないことであり、それは低放射化セメントや石灰石骨材を用いたり、高炉スラグや石炭灰を用いないことである.放射化しやすい各種とはEuとCoである.     

Performance analysis of various system configurations on grid-connected residential PV systems

Performance and loss analysis of residential photovoltaic (PV) systems are conducted using the sophisticated verification (SV) method. Performance of the various system configurations is quantitatively analyzed and compared in this paper. The south-oriented systems have approximately 22% more reference yield than the systems that are not oriented south. Difference of the module manufacturers shows more than 10% differences of the performance ratio whereas array configuration shows less difference. Imbalance of the string voltages causes system peak power loss and MPP mismatch. This loss cannot be minimized by the DC/DC converter in most of the systems.     

复杂光学系统中的干涉条纹图像的精确仿真方法

精密复杂曲面形状的干涉测量光学系统的设计和测量误差分析一般采用光线追迹的方法进行,但用传统方法进行追迹计算时,计算结果不能用直观的干涉条纹仿真图像的形式来表示,常常难以有效地进行分析和判断.在提出的考虑光学元件安装误差的精确光线追迹方法的基础上,对来自于测量对象面的物体光的光程差的精确计算方法、和与物体光的位置对应的参照光侧的光线追迹方法进行探讨,给出物体光与参照光的位相差的精确计算方法,提出一种实用的干涉条纹仿真图像的作成方法,及测量对象面仿真计算的初始化方法,再以平面测量试验片和齿轮齿面为对象,进行仿真计算和实测,验证所提出的方法的正确性.     

Fabrication of porous low crystalline calcite block by carbonation of calcium hydroxide compact

Calcium carbonate (CaCO₃) has been widely used as a bone substitute material because of its excellent tissue response and good resorbability. In this experimental study, we propose a new method obtaining porous CaCO₃ monolith for an artificial bone substitute. In the method, calcium hydroxide compacts were exposed to carbon dioxide saturated with water vapor at room temperature. Carbonation completed within 3 days and calcite was the only product. The mechanical strength of CaCO₃ monolith increased with carbonation period and molding pressure. Development of mechanical strength proceeded through two steps; the first rapid increase by bonding with calcite layer formed at the surface of calcium hydroxide particles and the latter increase by the full conversion of calcium hydroxide to calcite. The latter process was thought to be controlled by the diffusion of CO₂ through micropores in the surface calcite layer. Porosity of calcite blocks thus prepared had 36.8–48.1% depending on molding pressure between 1 MPa and 5 MPa. We concluded that the present method may be useful for the preparation of bone substitutes or the preparation of source material for bone substitutes since this method succeeded in fabricating a low-crystalline, and thus a highly reactive, porous calcite block.     

Al-laminated film packaged organic radical battery for high-power applications

A 100-mAh class of aluminum-laminated film packaged organic radical battery with a poly(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl methacrylate) (PTMA) composite cathode and a graphite anode has been fabricated. Its total weight was 22 g and the thickness was 4.3 mm. Because PTMA comprised only 6.2% of the total cell weight, the energy density was considerably less than that of a lithium ion battery. However, the power density per active material weight was found to be better than that of lithium ion battery. The applications which require high-power capability rather than high-energy density, such as the sub-battery in electronic devices and motor drive assistance in electric vehicles, would be appropriate for organic radical batteries in the future.