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Crystal Si micro-tip arrays were fabricated by selective anodization of p⁺-type Si substrate using an n-type doped layer as mask. The use of p⁺-type substrate gave rise to sideway anodization with a moderate degree of current restriction patterning effect under the n-type mask layer, and triggered the formation of a sharp tip on the Si substrate. A process that allows for the fabrication of tip arrays with a self-aligned gate electrode was also studied. In the latter process, anodization through a donut-shape window within the n-type doped area prompted the formation of a tip with surrounding Si wall with the top n-type layer as a gate.

To understand the behavior of dispersed molten metal particles dropped into water during the premixing process of steam explosion, experiments were performed by using heated stainless-steel particles simulating dispersed molten metal particles. High-frame-rate neutron radiography was successfully employed for visualization and void fraction measurement. Visualization was conducted by dropping heated stainless-steel particle into heavy water filled in a rectangular tank with the particle diameter (6, 9, and 12mm) and temperature (600°C, 700°C, 800°C, and 1000°C) as parameters. Steam generation due to direct contact of heated particle and heavy water was successfully visualized by the high-frame-rate neutron radiography at the recording speed of 500frames/s. From void fraction measurement it was revealed that the amount of generated steam was in proportion to the particle size and temperature. It is suggested that the ambient liquid might be superheated by the particle-liquid contact.

To elucidate the role of thrombin in brain damage during focal cerebral ischemia, we investigated the effects of a selective thrombin inhibitor, argatroban, on microthrombi formation, regional cerebral blood flow (rCBF), infarct areas and neurological deficits using a rat thrombotic distal middle cerebral artery (dMCA) occlusion model. The rat dMCA was occluded by a platelet-rich thrombus formed after photochemical reaction between rose bengal and green light. One day after dMCA occlusion, the number of microthrombi were counted. In the separate animals, rCBF was measured by using the iodoantipyrine method 1 day after dMCA occlusion. Three days after dMCA occlusion, behavioral tests were performed and the size of the cerebral infarction was determined. In the present study, argatroban was administered i.p. by continuous infusion after dMCA occlusion. Argatroban (0.3 mg/h/rat) significantly (P < .05) decreased the number of microthrombi 1 day after dMCA occlusion. Argatroban (0.1 and 0.3 mg/h/rat) significantly (P < .01) reversed a decrease in rCBF 1 day after dMCA occlusion. Argatroban (0.3 mg/h/rat) also significantly (P < .01) reduced the size of the cerebral infarction. Administration of argatroban (0.1 and 0.3 mg/h/rat) resulted in a significant improvement in neurological deficits 3 days after dMCA occlusion (P < .01 and P < .05, respectively). Argatroban decreased the size of the cerebral infarction and improved neurological deficits in the rat thrombotic dMCA occlusion model. These effects were thought to be due to the improvement of rCBF and to the reduction in secondary thrombus formation after dMCA occlusion.

Freeze-drying is a practical method of synthesizing powders for superconductors, because freeze-dried powders are fine, porous and homogeneous. In our previous studies, we had prepared the fine powders for the YBCO superconductor using freeze-drying of the suspensions obtained by coprecipitation of carbonates. These powders had been confirmed to be good materials for superconductors. Furthermore, YBCO superconductors had been produced from these powders, and had shown good electric and magnetic properties. In this paper, we report on complex oxides for YBCO superconductor using freeze-drying of suspensions obtained by simultaneous hydrolysis of metal isopropoxides. These powders were also confirmed to be useful for YBCO superconductors from the results of characterizations, such as elementary analyses by ICPS, EPMA images, SEM micrographs, DTA and TGA analyses.

In order to prepare fine Y-Ba-Cu oxides, a suspension of oxide was synthesized by simultaneous hydrolization of 2-propanol solution of yttrium triisopropoxide - barium diisopropoxide - copper diisopropoxide. The suspension could not be dried by the freeze-drying method because the freezing point of aqueous alcohol solvent in the suspension was so low: therefore, supercritical fluid drying was used. Although the diameters of dried powders were larger than expected, the powders containing no BaCO3 were obtained.The results from this experiment suggest that the supercritical fluid drying method is useful for drying a suspension prepared by the alkoxide method.

The temperature distribution in internal reforming SOFC anodes can be visualized by thermography. However, thermal imaging techniques are limited since they cannot take into account the influence of emissivity changes caused by carbon deposition on the anode. This problem can be solved by simultaneous visualization using thermography and visible light imaging. By combining these techniques, carbon deposition can be monitored via visible light imaging, whilst temperature changes due to the reforming reaction can be monitored by thermal imaging. This in operandovisualization technique enables the evaluation and prediction of the distribution of multiple chemical reactions on the SOFC electrodes.