Corona discharge could be a serious hazard to the outdoor insulation of a high-voltage (HV) system and also is an important detection issue for insulation status diagnosis. In this study, a double-helix-ultrasonic-array (DHUA) sensor was developed for corona positioning, which showed a good sensitivity to the ultrasonic signal originating from corona discharge and a satisfied directional respon...

Design of Converter transformer insulation is a major challenge. The insulation of these transformers is stressed by both AC and DC voltages. Particle contamination is one of the major problems in insulation structures, as they generate partial discharges leading it to major failure of insulation. Similarly corona discharges occur in transformer insulation. This partial discharge due to particl...

Onions can be stored for six months or longer at recommended storage conditions of 0° C and 6570% relatively humidity (RH) (Hardenburg, et al., 1986). Under low humidity storage, onions can suffer substantial moisture loss resulting in reduced salable product. However, under high humidity, onions may develop blue and black mold as well as soft rot caused by spp, , and , respectively. Corona dis...

Unique patterns of biomarkers were reproducibly characterized by matrix-assisted laser desorption ionization (MALDI)-mass spectrometry and were used to distinguish Bacillus species members from one another. Discrimination at the strain level was demonstrated for Bacillus cereus spores. Lipophilic biomarkers were invariant in Bacillus globigii spores produced in three different media and in B. g...

To miniaturize airborne particulates sizing and counting apparatus for ubiquitous deployment in air quality monitoring and epidemiological studies, we developed a unipolar corona discharge microfabricated ionizer structure for gases at atmospheric pressure and composition. It consumes relatively low power at 150mW or less, and operates with either single or multiple discharge electrodes. Potent...

Similar to AC system, the insulation system of DC system also gets affected. The HVDC station is a challenging environment for measurement of partial discharge level due to very high interference levels caused from the switching of thyristor-controlled converters. There is also significant interference from external air-corona due to high electric stress at the surface of conductors and hardwar...

Laser based lightning control holds a promising way to solve the problem of the long standing disaster of lightning strikes. But it is a challenging project due to insufficient understanding of the interaction between laser plasma channel and high voltage electric filed. In this work, a direct observation of laser guided corona discharge is reported. Laser filament guided streamer and leader ty...

Pulsed corona discharge processes utilize chemical radicals and ions and highly reactive molecules produced from a high voltage pulsed electrical discharge that is sustained in an aqueous phase medium. Recently, such processes have been used for treating organic contaminants from wastewater. The principle objective of this work is to optimize the hydrogen peroxide needed in the flow reactor to ...

The visible vibronic emission spectrum was recorded from the corona discharge of precursor 1,2,3,4tetramethylbenzene with a large amount of inert carrier gas helium using a pinhole-type glass nozzle coupled with corona excited supersonic expansion. The spectrum showed a series of vibronic bands in the D1 → D0 electronic transition of jet-cooled benzyl-type radicals formed from the precursor in ...

The formation of negative ions produced in a negative point-to-plane corona discharge fed by a Ar/N2/CH4 gas mixture has been studied using mass spectrometry. The measurements were carried out in flowing regime at ambient temperature and a reduced pressure of 460 mbar. The CN− anion has been found to be the most dominant negative ion in the discharge and is believed to be the precursor of heavi...