Search

Corona is a luminous, audible discharge that occurs when there is an excessive localized electrical field gradient upon an object that causes ionization and possible electrical breakdown of the fluid such as air adjacent to this object that is electrically charged. A corona ring also called an anti-corona ring or grading ring is a toroid of conductive material, usually a metal, attached to a terminal of high voltage equipment. The role of a corona ring is to distribute the electrical field gradient and lower its maximum values below the corona threshold, thus prevent corona discharge. Corona rings having larger diameter have a lower electric field gradient at the surface. Hence, corona rings having larger diameter produce lower corona discharge compared to corona rings with a smaller diameter. We know that coating Nanoparticles on the surface of the material increases the area to volume ratio, thus coating the corona ring using electrically conductive Nanoparticles increases the surface area of the ring and helps in improving electrical field distribution which results in reduced voltage stress per area on the ring and thereby reducing the corona discharge. [ABSTRACT FROM AUTHOR]

A nano fluid is a liquid that contains nanoparticles. This research looked at the synthesis and dielectric strength of a 5 percent nickel doped aluminium oxide nanofluid with IS-335 as the base fluid, which is the most often used oil in transformers. Combustion was used to make nickel doped aluminium oxide nanoparticles. X-ray diffraction and EDX were used to identify them. This work investigates the effects of varying nanoparticle concentrations on transformer oil dielectric strength. The nickel doped aluminium oxide nanoparticles will raise the breakdown strength of the base oil by 64.28 percent, hence improving the transformer oil's breakdown strength. [ABSTRACT FROM AUTHOR]

n-ZnO core @ Cu/p-CuO multishell nanoparticles were synthesized by a two step wet chemical process. In the first step, wurtzite ZnO nanoparticles were prepared by simple precipitation technique using ZnCl2 and NaOH precursors. The prepared nanoparticles were further powdered by ball milling technique. The prepared ZnO nanoparticles were coated with copper shell by electroless plating technique. The CuO film was later formed on the copper shell by air oxidation. The ZnO@Cu/CuO coremultishell nanoparticles were characterized using elemental analysis, X-ray diffraction and electron microscopic studies. BET nitrogen gas adsorption technique was employed to determine the specific surface area of ZnO@Cu/p-CuO core-multishell nanoparticles. Diffused reflectance spectroscopy (DRS) was used to measure the band gap of core-multishell nanoparticles. Tauc plot was use to determine the optical band gap (Eg) of the nanoparticles. The DRS analysis suggests the Core-multishell nanoparticles have wide band gap from near ultraviolet to visible and better light absorption strength. The n-ZnO @ Cu/p-CuO core-multishell nanoparticles may find application in solar energy harvesting. [ABSTRACT FROM AUTHOR]