Gray (unit) Gray (unit) The gray (symbol: Gy) is a derived unit of ionizing radiation dose in the International System of Units (SI). It is defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose which measures the energy deposited in a unit mass at a certain position, and of the radiation quantity kerma, which is the amount of energy that is transferred from photons to electrons per unit mass at a certain position. The corresponding cgs unit to the gray is the rad (equivalent to
Dual Work Exchanger Energy Recovery Dual Work Exchanger Energy Recovery The Dual Work Exchanger Energy Recovery (DWEER) is an energy recovery device. In the 1990s developed by DWEER Bermuda and licensed by Calder AG for use in the Caribbean. Seawater reverse osmosis (SWRO) needs high pressure and some of the reject stream can be reused by using this device. According to Calder AG, 97% of the energy in the reject stream is recovered. The DWEER system uses a piston doublechamber reciprocating hydraulically driven pump, and a patented valve system in a high pressure batch process with large pressure vessels, similar to a locomotive, to capture