on-and-off combustion cycle
51environment — environmental, adj. environmentally, adv. /en vuy reuhn meuhnt, vuy euhrn /, n. 1. the aggregate of surrounding things, conditions, or influences; surroundings; milieu. 2. Ecol. the air, water, minerals, organisms, and all other external factors… …
52Carbon sink — A carbon sink is reservoir of carbon that accumulates and stores carbon for an indefinite period. The main natural sinks are: # Absorption of carbon dioxide by the oceans # Photosynthesis by plants and algae The process by which carbon sinks… …
53Reaction Engines SABRE — infobox rocket engine imsize=220 caption=A model of the SABRE name=Reaction Engines SABRE country of origin=UK status=R D type=liquid fuel=Liquid hydrogen oxidiser=LOX cycle=combined cycle precooled jet engine + closed cycle rocket engine… …
54international relations — a branch of political science dealing with the relations between nations. [1970 75] * * * Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political… …
55Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
56VTEC — is also an abbreviation for the verocytotoxin producing Escherichia coli strain O157:H7 .: For the education institution, see Virginia Tech. VTEC (Variable Valve Timing and Lift Electronic Control) is a valvetrain system developed by Honda to… …
57PCV valve — The Positive Crankcase Ventilation valve, or PCV valve, is a one way valve that ensures continual evacuation of gases from inside a gasoline internal combustion engine s crankcase.ExplanationAs an engine runs, gases and combustion pressure are… …
58hydrosphere — /huy dreuh sfear /, n. the water on or surrounding the surface of the globe, including the water of the oceans and the water in the atmosphere. [1885 90; HYDRO 1 + SPHERE] * * * Discontinuous layer of water at or near the Earth s surface. It… …
59Nobel Prizes — ▪ 2009 Introduction Prize for Peace The 2008 Nobel Prize for Peace was awarded to Martti Ahtisaari, former president (1994–2000) of Finland, for his work over more than 30 years in settling international disputes, many involving ethnic,… …
60Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …
