CT: Cathodic protection is employed intensively on the steel drains in oil and gas industry. It is a technique of prevention against the corrosion which transforms the structure into a cathode of a corrosion cell ; Two types of cathodic protection systems are usually applied : The galvanic protection systems use the galvanic anodes, also called the sacrificial anodes, which are electrochemically more electronegative than the structure to be protected, the other system is by imposed current, powered by electrical generator with D.C. output towards the structure to be protected. The object of this study is to design a cathodic protection system by impressed current supplied with solar energy panels applied to a pipeline.
S: http://www.cder.dz/spip.php?article348 (last access: 25 February 2015)
N: 1. cathodic (adj): From cathode (n.), 1834, from Latinized form of Greek kathodos “a way down,” from kata- “down” + hodos “way”. Proposed by the Rev. William Whewell (1794-1866), English polymath, and published by English chemist and physicist Michael Faraday (1791-1867). So called from the path the electric current was supposed to take. Related: Cathodic; cathodal. Cathode ray first attested 1880, but the phenomenon known from 1859; cathode ray tube is from 1905.
protection (n): mid-14c., “shelter, defense; keeping, guardianship;” late 14c. as “that which protects,” from Old French proteccion “protection, shield” (12c.) and directly from Late Latin protectionem (nominative protectio) “a covering over,” noun of action from past participle stem of protegere “protect, cover in front,” from pro- “in front” + tegere “to cover”.
2. A technique employed to minimize the rate of electrochemical corrosion of large structures, such as floating vessels or oil drilling and production platforms, storage tanks, and pipelines. There are two methods of applying cathodic protection, active and passive. In either case the structure is regarded as the cathode in an electrolytic cell, the anode being an attached metal bar, bracelet or plate, and the electrolyte the separating medium. Source 2, fiche 1, Anglais, Définition 1 – cathodic%20protection
3. Cathodic protection involves the use of a galvanic or impressed direct electric current to render the pipeline cathodic, thus causing it to be a negative element in the circuit.
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=cathodic+protection&searchmode=none (last access: 25 February 2015). 2 & 3. TERMIUMPLUS.