Particle Charging in DC Corona Fields
After a brief review of the currently accepted theory of particle charging in corona fields in air by both ionic bombardment and diffusion in the dark space surrounding the dc corona glow, the paper presents some of the recently published findings on particle charging within the corona glow. The study was made possible by the discovery that additions of CO2 to air in a 5 to 20% range will increase a cylindrical positive corona glow to a size which is sufficiently large to allow particles to be dropped on to various trajectories parallel to the corona wire and their charge to be measured. The influence of the shape of the particles when exposed to corona charging is also discussed.
Polarity effect on the electrohydrodynamic (EHD) spray of water
Abstract This paper presents the effects of polarity on the electrohydrodynamic (EHD) spray of water (deionized and tap water) in air and pure CO 2 environments. Its influence in the interaction of the EHD spray and corona discharges was experimentally measured and analyzed. In contrast to the various spray patterns observed under positive polarity, negative polarity induced only two modes (dripping and spindle) under the typical conditions used in this study. Mapping of electrospray modes is presented in conjunction with current–voltage characteristics, discharge and spray images obtained with ICCD and high-speed camera. We also first report the intermittent multi-jet mode in water in pure CO 2 . The essential differences in the spindle mode were the shape and elongation direction of the water filaments according to the negative or positive polarity. The different spray patterns in the spindle mode seemed to be associated with the movement of ion species in water. From the combined analysis of the corona discharges, one may conclude that the different properties of the coronas were associated with the spray patterns in both air and pure CO 2 . Typical onset streamers in air under positive polarity had minimal influence on the spray mode because they were found to be separated in time and space from the water meniscus. In contrast to the stable glow under positive polarity, many current pulses (Trichel pulse) were observed in the negative EHD spray.
Japanese women marriage migrants today : negotiating gender, identity and community in search of a new lifestyle in Western Sydney
...................................................................................................................... vi CHAPTER 1. LIFESTYLE MIGRANT, CONSEQUENT SETTLER AND MARRIAGE MIGRANT ............................................................................................. 7 1.