Electron emission Insulating polymers HVDC Polymer Aluminum oxide Electrical engineering Bipolar charge transport model E-Beam Breakdown Partial discharges PEA Atomic force microscopy Luminescence Charge transport model Rotating machines Polymeric insulation Pulsed electro acoustic method C-AFM Polymers Cross-linking by-products DC conductivity EFM Thin films Plasma processes Transport Proteins Cable Polarity reversal Dielectric material Silicon compounds Electrodes LDPE Polyimide Electric field Mechanical properties Power cables Charge trapping Ac electric field Dielectric properties Electrical conductivity Insulation Space charge Electron-beam irradiation Charge d'espace Electrical properties Polypropylene Electrical ageing Electron beam Conductivity Polarization Charge injection Cumyl alcohol Cathodoluminescence SiO2 Electromechanical stress Electric field distribution Electrostatics Polyethylene KPFM Optimization Dielectric materials PTFE Interfacial charge Silver nanoparticles AgNPs Conduction current Electron beams Plasma process Fluid model DC stress FTIR Silver Radiation effects Dielectric strength Electric potential Dielectrics Electrical insulation HVDC cable Dielectric Accumulation characteristics Dielectric charging XLPE Nanostructured dielectrics Ageing Electroluminescence AFM Charge measurement Cross-linked polyethylene Modeling FLIMM Permittivity LIMM Thermal aging Epoxy resin Current measurement Acoustic wave propagation Electronic irradiation Dielectric films Charge transport Field distribution