Partial discharge Partial discharge In electrical engineering, partial discharge (PD) is a localized dielectric breakdown (DB) of a small portion of a solid or fluid electrical insulation (EI) system under high voltage (HV) stress, which does not bridge the space between two conductors. While a corona discharge (CD) is usually revealed by a relatively steady glow or brush discharge (BD) in air, partial discharges within solid insulation system are not visible. PD can occur in a gaseous, liquid or solid insulating medium. It often starts within gas voids, such as voids in solid epoxy insulation or bubbles in transformer oil. Protracted partial
Meaning (philosophy of language) individual speaker in a particular context wants to refer to. The word "dog" is an example of a meaning, but pointing at a nearby dog and shouting "This dog smells foul!" is an example of usage. From this distinction between usage and meaning arose the divide between the fields of Pragmatics and Semantics. Yet another distinction is of some utility in discussing language: "mentioning". "Mention" is when an expression refers to itself as a linguistic item, usually surrounded by quotation marks. For instance, in the expression "'Opopanax' is hard to spell", what is referred to is the word itself ("opopanax")