Electrical equipment is always subjected to various of operating conduction and voltage waves which cause insulation failure on the surface of pressboard (PB). In this paper. pre-breakdown streamers of surface discharge on the interface of PB in vegetable oil based Fe3O4 nanofluids (NFs) were observed by the shadowgraph method under lightning impulse voltage. The images indicate that ... https://www.mamapaisa.com/product-category/curl-revitalizer/