Eucommia ulmoides gum History of engineering & technology Langmuir Materials science SiC crystal form Technology: general issues active product alumina nanoplates antioxidant 4010NA aramid nanofiber arcing breakdown field strength breakdown strength carbon nanotubes corona discharge creepage distance curved profiles damping performance dielectric elastomer droplet vibration electric breakdown strength electro-thermal dissociation electromagnetic shielding energy harvesting epoxy resin epoxy resins frequency graphene graphene oxide graphitic carbon nitride nanosheets