Criteria
A machine consists of a power source and a mechanism for the controlled use of this power. The power source often relies on chemical conversion to generate heat which is then used to generate power. Each stage of the process of power generation has a maximum performance limit which is identified as ideal.
Once the power is generated the mechanism components of the machine direct it toward useful forces and movement. The ideal mechanism does not absorb any power, which means the power input is equal to the power output.
An example is the automobile engine (internal combustion engine) which burns fuel (an exothermic chemical reaction) inside a cylinder and uses the expanding gases to drive a piston. The movement of the piston rotates the crank shaft. The remaining mechanical components such as the transmission, drive shaft, differential, axles and wheels form the power transmission mechanism that directs the power from the engine into friction forces on the road to move the automobile.
The ideal machine has the maximum energy conversion performance combined with a lossless power transmission mechanism that yields maximum performance.
Read more about this topic: Ideal Machine
Famous quotes containing the word criteria:
“There are ... two minimum conditions necessary and sufficient for the existence of a legal system. On the one hand those rules of behavior which are valid according to the system’s ultimate criteria of validity must be generally obeyed, and on the other hand, its rules of recognition specifying the criteria of legal validity and its rules of change and adjudication must be effectively accepted as common public standards of official behavior by its officials.”
—H.L.A. (Herbert Lionel Adolphus)
“Every sign is subject to the criteria of ideological evaluation.... The domain of ideology coincides with the domain of signs. They equate with one another. Wherever a sign is present, ideology is present, too. Everything ideological possesses semiotic value.”
—V.N. (Valintin Nikolaevic)
“We should have learnt by now that laws and court decisions can only point the way. They can establish criteria of right and wrong. And they can provide a basis for rooting out the evils of bigotry and racism. But they cannot wipe away centuries of oppression and injustice—however much we might desire it.”
—Hubert H. Humphrey (1911–1978)