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Efficiency is very often confused with effectiveness. In general, efficiency is a measurable concept, quantitatively determined by the ratio of useful output to total useful input. Effectiveness is the simpler concept of being able to achieve a desired result, which can be expressed quantitatively but does not usually require more complicated ...
Energy conversion efficiency depends on the usefulness of the output. All or part of the heat produced from burning a fuel may become rejected waste heat if, for example, work is the desired output from a thermodynamic cycle. Energy converter is an example of an energy transformation.
energy efficiency: unitless (dynamic) viscosity (also ) pascal second (Pa⋅s) theta: angular displacement: radian (rad) kappa: torsion coefficient also called torsion constant newton meter per radian (N⋅m/rad) lambda: cosmological constant
A branch of physics that studies atoms as isolated systems of electrons and an atomic nucleus. Compare nuclear physics. atomic structure atomic weight (A) The sum total of protons (or electrons) and neutrons within an atom. audio frequency A periodic vibration whose frequency is in the band audible to the average human, the human hearing range.
Atom economy. Atom economy (atom efficiency/percentage) is the conversion efficiency of a chemical process in terms of all atoms involved and the desired products produced. The simplest definition was introduced by Barry Trost in 1991 and is equal to the ratio between the mass of desired product to the total mass of reactants, expressed as a percentage.
Efficiency must be less than 100% because there are inefficiencies such as friction and heat loss that convert the energy into alternative forms. For example, a typical gasoline automobile engine operates at around 25% efficiency, and a large coal-fuelled electrical generating plant peaks at about 46%.
This is a consequence of the first law of thermodynamics, as for the total system's energy to remain the same; + = (+) =, so therefore = (), where (1) the sign convention of heat is used in which heat entering into (leaving from) an engine is positive (negative) and (2) is obtained by the definition of efficiency of the engine when the engine ...
Energy efficiency may refer to: Energy efficiency (physics), the ratio between the useful output and input of an energy conversion process Electrical efficiency, useful power output per electrical power consumed; Mechanical efficiency, a ratio of the measured performance to the performance of an ideal machine