Dendrite silver was synthesized on the carbon fiber by pulse electro-deposition method in AgNO3 aqueous solution. The morphology of the silver changed from dendrite to plate like crystal, and the formation mechanism was investigated by using continuous wave (CW) potential and rectangular wave potential. The fractal dimension of the silver tree deposited at 10 Hz showed the highest value in the each low of the potential, VL, of rectangular wave. The shape of the silver tree is able to control by adjusting the frequency of the rectangular wave that applied for electro-deposition.
A 3-channel (3C) microinjector was prepared by pulling a glass capillary. One channel was used for a potential measuring electrode (MeaE) and the other two channels were used for electrophoretic introduction electrode (IntE) and its counter electrode (CE). The 3C microinjector was propelled by an oil pressure manipulator that was driven by a pulse motor, while the MeaE output was recorded continuously. When the 3C microinjector penetrated the cell membrane of a tobacco cultured cell, BY-2, the output potential changed sharply towards the negative direction. Then the microinjector progressed further into the cell. A marked change of the output potential occurred again, though it was towards the positive direction. These changes were speculated as the passages of cell membrane and vacuolar membrane, respectively. Using the differential of these changes as the stop signal, the microinjector could rightly be stopped either in the cytosol or the vacuole, which was confirmed by the dye diffusion pattern.
‘HAYABUSA’ is a Japanese interplanetary spacecraft for the exploration of an asteroid named ‘ITOKAWA.’ The spacecraft is powered by a 13.2 Ah lithium-ion secondary battery. To realize maximum performance of the battery for long flight operation, the state-of-charge (SOC) of the battery was maintained at ca. 65% during storage in case it is required for contingency operations. To maintain this SOC condition, the battery is charged once a week. We further charge the battery up to 4.1 V/cell using bypass circuits to balance the cells every four months. The capacity of the battery was measured during the flight operation, which revealed the appropriate capacity for the expected mission.
Self-assembled mixed monolayers (mixed SAMs) composed of 11-ferrocenyl-1-undecanethiol (11-FUT) and hexanethiol (HT) molecules were prepared through an exchange method and characterized by multicycle electrochemical desorption-adsorption voltammetry. The first cycles of the voltammograms showed a single desorption peak although the SAMs have a domain structure composed of compact 11-FUT molecules, indicating that some residual HT molecules were present in 11-FUT domains and that complete phase separation did not take place in the mixed SAMs. The structure, however, altered toward a mildly phase-separated structure when the mixed SAMs experienced desorption-adsorption cycle(s), and two separate reductive desorption peaks were found in the second cycles of voltammograms, which clearly evidenced that all mixed SAMs (before voltammetric analysis), including those prepared by prolonged exchange reactions, really contained both 11-FUT and HT molecules. This demonstrates the importance of such multicycle voltammetry for mixed SAMs that are usually characterized and discussed only in terms of the first reductive, or negative-going, scan of voltammograms. Even after the desorption-adsorption cycle(s), ferrocenyl groups in mixed SAMs underwent FeII/FeIII redox, while the intensity of redox peaks became weakened.
The simulation code for the pyrochemical processing of spent nuclear fuels was developed to analyze experimental data, to predict experimental results, and to propose adequate conditions and processes. The Simulation code for Pyrochemical Reprocessing (SPR) is based on calculations of chemical equilibrium and electrochemical reactions. The code also includes the calculations of the current-potential distribution between the electrodes. Some calculations were made to simulate the experimental results on the electro-codeposition process of UO2 and PuO2. The phenomena of the redox reactions between Pu4+ and Pu3+ ions and those between Fe3+ and Fe2+ ions were theoretically analyzed; these redox reactions cause the low current efficiency in the electrocodeposition process. The calculated current-potential distribution around the cathode corresponds to the observed distribution of the oxide deposited on the cathode.