Energy content of biofuel Energy content of biofuel The Energy content of biofuel is a description of the potential energy contained in a given biofuel, measured per unit mass of that fuel, as specific energy, or per unit of volume of the fuel, as energy density. A biofuel is a fuel, produced from living organisms. Biofuels include bioethanol, an alcohol made by fermentation—often used as a gasoline additive, and biodiesel, which is usually used as a diesel additive. Specific energy is energy per unit mass, which is used to describe the energy content of a fuel, expressed in SI units as joule per kilogram
History of UNIT alien threats, and Sarah Jane is concerned that UNIT would treat her son Luke as a test subject with no regard for his human rights should they discover him. UNIT returned in the 2009 Easter special "Planet of the Dead" investigating the disappearance of the 200 bus. Captain Erisa Magambo makes a reappearance from her last in "Turn Left" as the commander of UNIT, aided by the new scientific adviser Malcolm Taylor. They appeared again during "Death of the Doctor" which introduced a UNIT Base at Mount Snowdon. In 2012, after a 3-year absence, UNIT returned to "Doctor Who" in