Specific heat anomaly of nonstoichiometric U4O9−y

A λ-type specific heat anomaly of U₄O_9?y, which occurs slightly above room temperature, was measured for the samples with different O/U ratios. The transition temperatures obtained from the peak of λ-type specific heat anomaly are in fairly good agreement with the data by X-ray diffraction and electrical conductivity measurements. The entropy increment for the transition was obtained to be 0.46 e.u. for UO_2.250, 0.56 e.u. for UO_2.240 and 0.70 e.u. for UO_2.228, depending on O/U ratio. On the basis of the entropy change with O/U ratio, the mechanism of the phase transition is discussed. The entropy change due to the phase transition is mainly divided into two terms: one is due to the order-disorder rearrangement of U(IV) and U(V) ions,the other is associated with the displacement of oxygens ions. The former term is estimated to be rather smaller than the entropy change calculated by the Bragg-Williams approximation, and the latter is calculated using the X-ray diffraction data with the assumption of the Willis model.     

Nonequilibrium dynamics of a reacting network system

The nonlinear nonequilibrium properties of reacting network systems are studied by computer simulations. It is shown that the fluctuation in the population of each chemical species obeys a log-normal distribution, not the normal Gaussian distribution. The reaction rate shows power-law decay with activation cost (energy), not the Arrhenius-type exponential decay observed in a linear nonequilibrium regime. These two characteristic features will explain the diversity, plasticity, and adaptivity observed in complex biological reaction networks. This work was presented in part at the 13th International Symposium on Artifical Life and Robotics, Oita, Japan, January 31–February 2, 2008     

日本彩色聚乙烯涂覆钢管的开发

试验了彩色聚乙烯涂覆钢管的耐腐蚀性和耐气候性，由于聚乙烯涂层隔绝水的作用，聚乙烯涂覆钢管具有优良的耐腐蚀性能，电阻绝缘值和优良的机械性能。建立了一个新的方式去研究分析聚乙烯抗老化剂消耗和在聚乙烯中的扩散。用有效测定的方法定量地预测彩色聚乙烯涂覆层的寿命，应用这些分析结果，不仅可使新的有色聚乙烯涂覆钢管在恶劣腐蚀环境介质情况下具有高的耐腐蚀性，而且有长的耐气候性。     

Static Coarse Grain Task Scheduling with Cache Optimization Using OpenMP

Effective use of cache memory is getting more important with increasing gap between the processor speed and memory access speed. Also, use of multigrain parallelism is getting more important to improve effective performance beyond the limitation of loop iteration level parallelism. Considering these factors, this paper proposes a coarse grain task static scheduling scheme considering cache optimization. The proposed scheme schedules coarse grain tasks to threads so that shared data among coarse grain tasks can be passed via cache after task and data decomposition considering cache size at compile time. It is implemented on OSCAR Fortran multigrain parallelizing compiler and evaluated on Sun Ultra80 four-processor SMP workstation using Swim and Tomcatv from the SPEC fp 95. As the results, the proposed scheme gives us 4.56 times speedup for Swim and 2.37 times on 4 processors for Tomcatv respectively against the Sun Forte HPC Ver. 6 update 1 loop parallelizing compiler.     

Micronization of Dihydroartemisinin by Rapid Expansion of Supercritical Solutions

The purpose of this study was to prepare fine particles of antimalarial drug dihydroartemisinin (DHA) by rapid expansion of supercritical solutions (RESS) using carbon dioxide as supercritical fluid. The mechanical grinding by jet mill and additional vibration rod mill also was performed as a comparative method. In the RESS process, drug particles were prepared by varying processing conditions, including extraction condition, pre-expansion condition, nozzle diameter, nozzle temperature, and collecting distance. Particle size and morphology and physicochemical characteristics of the drug particles were investigated. The RESS process could produce the smaller drug particles (about 1–2 μm) when compared to mechanical grinding method (about 7 μm). All RESS processing parameters had an effect on size and morphology of drug particles. The particle size of drug was related to the solubility of drug in supercritical CO₂ at each processing condition. The fine particles of DHA (about 1 μm) with narrow size distribution could be obtained at extraction pressure of 18 MPa and extraction temperature of 32°C, which was closed to the critical temperature of supercritical CO₂ whereas broad size distribution was obtained at extraction temperature of 60°C. Powder X-ray diffraction study indicated that the RESS-processed particles were in crystalline form. The results revealed that RESS process is applicable for micronization of DHA.     

Experimental characterization of high-speed impact damage behavior in a three-dimensionally woven SiC/SiC composite

This paper discusses high-speed impact damage in a three-dimensionally woven SiC/SiC composite (3D-CMC). The impact damage was introduced by a steel ball projectile in 3D-CMC plates with and without thermal exposure. The surface and internal damages were observed by optical microscopy and X-ray CT. A crater was observed on the collision surface. The X-ray CT measurement revealed that multiple pyramid-shaped cone cracks were generated beneath the crater when the impact speed was relatively low. At an impact speed exceeding the critical speed, a spall fragment was ejected from the back surface, while no internal damage was observed in the fragment. The spall fracture mode differed between the virgin and the thermally-exposed specimens. This difference is the result of embrittlement of the fiber/matrix interface due to oxidation of the carbon coating layer in the thermally-exposed specimen. In addition, it is found that z-yarns improve impact resistance by constraining delamination.     

Effect of packed structure on flow behaviour in a trickle bed biofilter

The effects of operation conditions on the flow behaviour in gas–liquid countercurrent trickle bed biofilter were experimentally examined. In order to prevent gas channelling in the biofilter, packings with a relatively large void fraction, which have a role to maintain a high void fraction in the bed, were added. The gas and liquid velocities of the packed structure and the packings were changed, and the residence time distributions (RTDs) of the gas and liquid were measured. It was found that the addition of void supporters was very effective in the suppression of gas channelling.     

Positioning device for outdoor mobile robots using optical sensors and lasers

We propose a novel method for positioning a mobile robot in an outdoor environment using lasers and optical sensors. Position estimation via a noncontact optical method is useful because the information from the wheel odometer and the global positioning system in a mobile robot is unreliable in some situations. Contact optical sensors such as computer mouse are designed to be in contact with a surface and do not function well in strong ambient light conditions. To mitigate the challenges of an outdoor environment, we developed an optical device with a bandpass filter and a pipe to restrict solar light and to detect translation. The use of two devices enables sensing of the mobile robot’s position, including posture. Furthermore, employing a collimated laser beam allows measurements against a surface to be invariable with the distance to the surface. In this paper, we describe motion estimation, device configurations, and several tests for performance evaluation. We also present the experimental positioning results from a vehicle equipped with our optical device on an outdoor path. Finally, we discuss an improvement in postural accuracy by combining an optical device with precise gyroscopes.     

Diel rhythms of calling behavior and pheromone production of oriental tobacco budworm moth,Helicoverpa assulta (Lepidoptera: Noctuidae)

Both calling behavior and titer of (Z)-9-hexadecenal (Z9-16: Al), the major sex pheromone component ofHelicoverpa assulta, in pheromone glands showed distinct diel periodicity, and these two were synchronous. Calling was most actively performed and the pheromone titer reached a maximum from 2 to 6 h after lights-off. During photophase, no calling was shown and only a relatively small amount of Z9-16:A1 was detected. However, there was a time lag of a few days between peak calling activity and maximum pheromone titer. The pheromone titer was maximal from age 1 day to age 5 days and thereafter decreased while calling was most actively performed after age 3 days. Titers of three minor components, hexadecenal, (Z)-11-hexadecenal, and (Z)-9-hexadecenyl acetate, showed similar daily fluctuation patterns to that of Z9-16:Al, but relative to the titer of Z9-16:Al, the titer of the two aldehyde components remained relatively constant whereas that ofZ9-16:Ac increased in the late scotophase.     

A behavioral model for optically powered OCT endoscope with a micro electrostatic vertical‐comb optical scanner

This paper presents a novel device architecture for optically actuated microelectromechanical systems (MEMS) endoscopes for optical coherence tomography (OCT) measurement. A 10‐mW infrared light beam at a wavelength of 1.5 µm is transferred through the single‐mode fiber to provide a scanning MEMS mirror with the drive voltage (maximum 11 V) by exciting a photovoltaic cell, while also providing with a secondary light beam at a wavelength of 1.3 µm for the OCT measurement. An electrostatic vertical comb‐drive optical scanner (1.5 mm × 2.0 mm × 0.5 mm) has been developed by using the deep reactive ion etching (DRIE) of a silicon‐on‐insulator (SOI) wafer. The design of the scanner module is discussed, along with the experimental results of electrostatic operation. An equivalent circuit model for the optical scanner is developed to explain the behavior of the optically powered actuation mechanism, including the hysteresis loop in the frequency response and the voltage dependence of oscillating angle (mechanical peak ±3.2°/7 V around the resonance frequency of 250 Hz). OCT measurement of a tissue is demonstrated to reconstruct the cross‐sectional image of a fingerprint at a resolution of lateral 40 µm × vertical 8 µm and penetration depth of 2.5 mm. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.