Iron(II) sulfide or ferrous sulfide (Br.E. sulphide) is a chemical compound with the formula FeS. In the oil/gas industry, iron sulfides are often present in a sour system due to reaction between corrosion products and hydrogen sulfide.
A material that conducts (see conduction) electricity poorly or not at all. If a voltage is applied to a dielectric, the atoms in the material arrange themselves in such a way as to oppose the flow of electric current. Glass, wood, and plastic are common dielectrics. (See insulator.)
Currents that are due to the polarization and magnetization of a medium determine the values of the mediumâs dielectric constant and permeability, as well as the velocity of electromagnetic-wave propagation in the medium and the natural frequency spectrum of the electromagnetic oscillations.