Optical investigation of fast pulsed discharge on surface of ceramics for environmental applications
Pulsed surface discharge on the surface of ceramics was investigated experimentally. Photon counting method was applied to clarify preceding phase of the discharges. The results indicated the effect of charge injection from electrodes. Pulsed surface discharge reactor for decomposition of nitrogen oxides utilizing honeycomb ceramics was proposed. Framing and streak observation was carried out with image converter cameras. Emission spectra from the discharge were investigated with spectrometer. Uniform surface discharges on honeycomb ceramics were successfully obtained utilizing pulsed power generator with a SI-thyristor.
Basic Characteristics of Dielectric Barrier Discharge Reactor Using Anodic Porous Alumina for NOx Removal
Dielectric barrier discharge (DBD), properly combined with porous ceramics and/or catalysts, is a promising technology for diesel exhaust gas treatment. In this study, anodic porous alumina, which has numerous pores with nanometer-order diameter and a high aspect ratio, has been examined for use as a barrier in a DBD reactor. The anodic porous alumina greatly improves the DBD reactor. Nevertheless, few reports describe DBD using the anodic porous alumina barrier. As described herein, the DBD reactor’s basic characteristics and NOx removal in atmospheric pressure air were studied to support its future development. Results were compared with those of a typical DBD to clarify the influence of anodic porous alumina on those characteristics.The electropolished 99.99% pure Al substrate was anodized in 1.0 M sulfuric acid of 10°C for 5 h at dc 24 V. The Al substrate and anodic porous alumina respectively act as the electrode and dielectric barrier of the DBD. The dry gas mixture of NO (several hundred ppm) / O2 (20%) / N2 was supplied into the DBD reactor at 1.0 L/min. The resultant voltage and current waveforms resembled those of a typical DBD. Results revealed that NO was mostly oxidized to NO2 ; about 20 ppm N2O was detected. Different from a typical DBD the NO2 increased characteristically as a function of operation time.
Magnetic assist and magnetic pulse compression for copper vapor laser
We have applied magnetic assist and magnetic pulse compression to copper vapor laser and studied the switching characteristics, especially with the attention to the energy dissipation characteristics. As for magnetic assist, a suitable delay time was studied. And 2-stage MPC was designed using a simulation code and an all solid state driver with SI thyristors was developed.