Rapid evaluation of oxidation catalysis by gas sensor system: total oxidation, oxidative dehydrogenation, and selective oxidation over metal oxide catalysts

The rapid evaluation of catalysis is an indispensable technology for the success of combinatorial chemistry. A small-sized, less expensive, easily operating screening is desirable for parallel settings which dramatically shortens the evaluation time. Recent advances in gas sensors have enabled us to use them for the rapid evaluation of oxidation catalysis. Three typical catalytic oxidations over metal oxide catalysts were evaluated by gas sensor systems optimized for each catalytic system. The first one is the total oxidation of carbon monoxide in air. Five catalytic combustion-type gas sensors were used in a parallel reactor system to shorten the evaluation time. The second one is the oxidative dehydrogenation (ODH) of ethane over the mixed oxide of nickel and iron. The evaluation of the ODH catalysis was performed by a selective olefin sensor which determines the concentration of C₂H₄ in C₂H₆. The third one is the selective oxidation catalysis of propane over alkali modified Fe/SiO₂. The effluents including CO, CO₂, aldehydes and ketones in propane were analyzed by the CO, CO₂ and semiconductor-type gas sensors selective toward aldehydes and ketones. These evaluation results indicated that gas sensors have a good potential for the rapid evaluation of oxidation catalysts.     

Design on semiconductor coupled SAW convolver

This paper presents results of a design study on a semiconductor coupled surface acoustic wave (SAW) convolver in which bi-directionally propagating SAWs, on a piezoelectric substrate with a high coupling coefficient, couple with bonded semiconductor diodes through multistrips. To obtain convolution signals with a high efficiency, we adopted a diode-balanced bridge structure for the nonlinear operation. We also found that the tapping pitches of the multi-strip electrodes have robustness against operation frequency variation and temperature-dependent variation on the delay of the SAW. We verified the effectiveness of the device in. a circuit simulation and an experiment on a test circuit, which was fabricated by using an epitaxial lift-off film-bonding process.     

Implementation of Fault-Tolerant GridRPC Applications

A task parallel application is implemented with Ninf-G, a GridRPC system. A series of experiments are conducted on the Grid testbed in Asia Pacific for three months. Through tens of long executions, typical fault patterns were collected, and instability of the network throughput was determined to be a major reason of the faults. Several important points are stressed to avoid task throughput decline due to the fault-recovery operations: Timeout minimization for fault detection, background recovery, redundant task assignments, and so on. This study also issues a steer for design of the automated fault-tolerant mechanism in an upper layer of the GridRPC framework.     

Intra-body data transmission for the personal area network

Intra-body communication is a wireless means of exchanging information within a personal area network (PAN) between wearable electronic sensors and devices. The feasibility of intra-body communication is confirmed through several experiments on signal propagation within the human body, and a human phantom is designed and used to obtain reproducible results over repeated experiments. Based on the results of these experiments, a prototype transmission system is constructed using aluminum electrodes powered by 3 V DC and operating in the 10.7 MHz frequency modulation (FM) band. This prototype is demonstrated to be capable of transmitting analog signals through the human subjects in the presence of external noise. Digital data transmission at 9600 bps is also achieved using newly fabricated 10.7 MHz frequency shift keying (FSK) transmitter and receiver devices. The carrier frequency of 10.7 MHz is the intermediate frequency of FM radio receivers, meaning that the proposed system can make use of a wide selection of inexpensive, commercial radio frequency devices.     

Multiple fuzzy state-value functions for human evaluation through interactive trajectory planning of a partner robot

The purpose of this study is to develop partner robots that can obtain and accumulate human-friendly behaviors. To achieve this purpose, the entire architecture of the robot is designed, based on a concept of structured learning which emphasizes the importance of interactive learning of several modules through interaction with its environment. This paper deals with a trajectory planning method for generating hand-to-hand behaviors of a partner robot by using multiple fuzzy state-value functions, a self-organizing map, and an interactive genetic algorithm. A trajectory for the behavior is generated by an interactive genetic algorithm using human evaluation. In order to reduce human load, human evaluation is estimated by using the fuzzy state-value function. Furthermore, to cope with various situations, a self-organizing map is used for clustering a given task dependent on a human hand position. And then, a fuzzy state-value function is assigned to each output unit of the self-organizing map. The robot can easily obtain and accumulate human-friendly trajectories using a fuzzy state-value function and a knowledge database corresponding to the unit selected in the self-organizing map. Finally, multiple fuzzy state-value functions can estimate a human evaluation model for the hand-to-hand behaviors. Several experimental results show the effectiveness of the proposed method.     

Adaptive Ray‐bundle Tracing with Memory Usage Prediction: Efficient Global Illumination in Large Scenes

This paper proposes an adaptive rendering technique for ray‐bundle tracing. Ray‐bundle tracing can be done by per‐pixel linked‐list construction on a GPU rasterization pipeline. This rasterization based approach offers significant benefits for the efficient generation of light maps (e.g., hardware acceleration, tessellation, and recycling of shaders used in real‐time graphics). However, it is inapplicable to large and complex scenes due to the limited capacity of the GPU memory because it requires a high‐resolution frame buffer and high‐capacity node buffer for the linked‐lists. In addition, memory overflow can potentially occur on the per‐pixel linked‐list since the memory usage of the lists is usually unknown before the rendering process. We introduce an adaptive tiling technique with memory usage prediction. Our method uses an appropriately tiled frame buffer, thus eliminating almost all of the overflow risks thanks to our adaptive tile subdivision scheme. Using this technique, we are able to render high‐quality light maps of large and complex scenes which cannot be computed using previous ray‐bundle based methods.     

Development of new‐type outdoor termination using composite insulator with SF6 gas: Commercial use for 77‐kV transmission lines and development for 154‐kV XLPE cable

Recently, composite insulators have been increasingly employed mainly for economic reasons. We have developed a new type of outdoor termination using a composite insulator, which can be installed horizontally on a steel tower in order to reduce the construction cost. In this outdoor termination, SF₆ gas is filled in the composite insulator and a cold shrinkable premolded rubber unit is applied instead of the combined use of a rubber‐molded stress relief cone, epoxy resin insulator and spring unit. The application of the composite insulator, SF₆ gas and cold shrinkable premolded rubber unit reduces the total weight and makes it possible to install the termination horizontally on the tower. The new‐type outdoor termination for 77‐kV XLPE cable has already been applied in commercial use and enabled a reduction of the construction costs for power transmission lines. A 154‐kV new‐type outdoor termination has been developed and its initial electrical tests were successfully completed. This paper describes the design and performance of both 77‐kV and 154‐kV new‐type outdoor termination, and a follow‐up survey of the 77‐kV new termination in a commercial use. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(4): 18– 26, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20511     

Creation of Titania Artificial Interfaces with Geometric Patterns by Using Microstereolithography and Aqueous Solution Techniques

Titania micropatterns with periodic arrangements were successfully formed on glass substrates for use with electromagnetic wave energy resonance and localizations in terahertz frequency ranges. Geometric arrangements of acrylic polygonal tablets with titania particle dispersions were fabricated by using micropatterning stereolithography. Moreover, periodically arranged full anatase‐phase titania tablets were created homogeneously through liquid‐phase crystal depositions of water solvent processes, using microtemplates fabricated by using the stereolithography system. The terahertz wave properties were measured and calculated by using a time‐domain spectroscopic system and finite‐difference time‐domain method.