Chemical Wave Propagation Preserved on an Inhibitory Field in the Ruthenium-Catalyzed Belousov–Zhabotinsky Reaction

Achilles' heel of a traveling pulse subject to a local external stimulus

The response of a traveling pulse to a local external stimulus is considered numerically for a modified three-component Oregonator, which is a model system for the photosensitive Belousov-Zhabotinsky (BZ) reaction. The traveling pulse is traced and constantly stimulated, with the distance between the pulse and the stimulus being kept constant. We are interested in the minimal strength of the spatially localized stimulus in order to eliminate the pulse. The use of a stimulus of small width allows us to detect the point in the pulse most sensitive to the external stimulus, referred to as the "Achilles' heel" of the traveling pulse, at which minimal strength of stimulus causes a collapse of the pulse. Our findings are demonstrated experimentally as well with the photosensitive BZ reaction.

Response of a chemical wave to local pulse irradiation in the ruthenium-catalyzed Belousov-Zhabotinsky reaction

The photo-sensitive Belousov-Zhabotinsky (BZ) reaction system was investigated to understand the response of wave propagation to local pulse stimulation in an excitable field. When the chemical wave was irradiated with a bright pulse or a dark pulse, the speed of wave propagation decreased or increased. The timing of pulse irradiation that significantly affected the speed of chemical wave propagation was different with the bright and dark pulses. That is, there is a sensitive point in the chemical wave. The experimental results were qualitatively reproduced by a numerical calculation based on a three-variable Oregonator model that was modified for the photosensitive BZ reaction. These results suggest that the chemical wave is sensitive to the timing of pulse irradiation due to the rates of production of an activator and an inhibitor in the photochemical reaction.

Holistic Characterization of Carbon Nanotube Membrane for Capacitive Deionization Electrodes Application

One of the main areas of improvement in capacitive deionization technologies is the materials used for electrodes which have very specific requirements. In the present work, a wide range of material characterization techniques are employed to determine the suitability of a multiwall carbon nanostructure thin film as electrode material. The electrical, mechanical, surface and wetting characteristics are studied proving the membrane highly conductive (σ=7.25 103 S/m), having competitive electro-sorption capacity (11.7 F/g at 10 mV/s) and surface area (149 m2/g), strain rate dependent mechanical properties and hydrophobic wetting behavior.