primary combustion
51Hybrid electric vehicle — The Toyota Prius is the world s top selling hybrid car, with cumulative global sales of 2.36 million units by August 2011.[1] A hybrid electric vehicle (HEV) is a type of hybrid vehicle and electric vehicle which combines a conventional internal …
52Ammonia — For other uses, see Ammonia (disambiguation). Ammonia …
53Fuel cell — For other uses, see Fuel cell (disambiguation). Demonstration model of a direct methanol fuel cell. The actual fuel cell stack is the layered cube shape in the center of the image A fuel cell is a device that converts the chemical energy from a… …
54Fossil fuel — Coal, one of the fossil fuels. Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes… …
55Nitrogen cycle — Schematic representation of the flow of nitrogen through the environment. The importance of bacteria in the cycle is immediately recognized as being a key element in the cycle, providing different forms of nitrogen compounds assimilable by higher …
56Diesel engine — Diesel engines in a museum Diesel generator on an oil tanker …
57Rocket engine — RS 68 being tested at NASA s Stennis Space Center. The nearly transparent exhaust is due to this engine s exhaust being mostly superheated steam (water vapor from its propellants, hydrogen and oxygen) …
58Motorcycle engine — A Honda Super Cub engine. The most popular motorcycle in history, with over 60 million produced …
59global warming — an increase in the earth s average atmospheric temperature that causes corresponding changes in climate and that may result from the greenhouse effect. [1975 80] * * * Potential increase in global average surface temperatures resulting from… …
60Scramjet — Part of a series on Aircraft propulsion Shaft engines (to drive pr …
