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
Home Energy Resources Unit Home Energy Resources Unit The Home Energy Resources Unit or Home Energy Recovery Unit (HERU) is a prototype kitchen appliance which is claimed to use household waste to generate energy. Household waste, both organic and inorganic, is placed into a main chamber. Plastic and cardboard packaging as well as food waste can be inserted as fuel, and the waste does not need to be sorted or separated. It then goes through an eight-hour cycle. The chamber containing the waste is heated to 100° celsius to evaporate water and remove oxygen. The temperature is then increased and pyrolysis takes place. Oxygen