excess noise temperature
81Fuel 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… …
82HVAC — may also stand for High voltage alternating current. See also: Glossary of HVAC HVAC systems use ventilation air ducts installed throughout a building that supply conditioned air to a room through rectangular or round outlet vents, called… …
83Earth sheltering — is the architectural practice of using earth against building walls for external thermal mass, to reduce heat loss, and to easily maintain a steady indoor air temperature. Earth sheltering is popular in modern times among advocates of passive… …
84Spark plug — A spark plug (also, very rarely nowadays, in British English: a sparking plug) is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed aerosol gasoline by means of an electric spark.… …
85diesel engine — a compression ignition engine in which a spray of fuel, introduced into air compressed to a temperature of approximately 1000° F (538° C), ignites at a virtually constant pressure. Also called diesel. [1890 95] * * * Internal combustion engine in …
86Drug — /droog/, n. Zoroastrianism. the cosmic principle of disorder and falsehood. Cf. Asha. [ < Avestan drauga] * * * I Any chemical agent that affects the function of living things. Some, including antibiotics, stimulants, tranquilizers,… …
87balloon flight — ▪ aviation Introduction passage through the air of a balloon that contains a buoyant gas, such as helium or heated air, for which reason it is also known as lighter than air free flight. Unmanned balloons have been used to carry meteorological… …
88bat — bat1 /bat/, n., v., batted, batting. n. 1. Sports. a. the wooden club used in certain games, as baseball and cricket, to strike the ball. b. a racket, esp. one used in badminton or table tennis. c. a whip used by a jockey. d. the act of using a… …
89fluid mechanics — an applied science dealing with the basic principles of gaseous and liquid matter. Cf. fluid dynamics. [1940 45] * * * Study of the effects of forces and energy on liquids and gases. One branch of the field, hydrostatics, deals with fluids at… …
90List of QI episodes (B series) — infobox tvseason season name = QI Series B caption = The front cover of the QI series B DVD, featuring Stephen Fry (left) and Alan Davies (right). dvd release date = 17 March, 2008 country = UK network = BBC first aired = 8 October, 2004 last… …
