The sum of the two quantities is called the total heat of the steam at 100°.
The second is the actual heat efficiency, or the ratio of the heat turned into work to the total heat received by the engine.
The total expenditure of heat of a man at rest must be equal to the total heat of combustion.
The quantity actually observed by Rowland was the total heat.
From this it is clear that the larger proportion of total heat of the body is supplied by the muscles.
Fully four-fifths of the total heat are used up in this molecular work, only one-fifth remaining to warm the battery.
The total heat developed by an ounce of zinc through its union with oxygen in the battery is also absolutely invariable.
Minimum thermal conductance occurs when total heat transfer through these layers is reduced to its lowest possible rate.
The total heat of the steam remains nearly constant, whatever be the temperature at which the vaporization occurred.
The thermal efficiency of an engine is the ratio of the heat transformed into work to the total heat supplied to the engine.
1927, from Greek enthalpein "to warm in," from en "in" (see en- (2)) + thalpein "to heat."
enthalpy en·thal·py (ěn'thāl'pē, ěn-thāl'-)
n.
A thermodynamic function of a system, equivalent to the sum of the internal energy of the system plus the product of its volume multiplied by the pressure exerted on it by its surroundings.
enthalpy A partial measure of the internal energy of a system. Enthalpy cannot be directly measured, but changes in it can be. If an outside pressure on a system is held constant, a change in enthalpy entails a change in the system's internal energy, plus a change in the system's volume (meaning the system exchanges energy with the outside world). For example, in endothermic chemical reactions, the change in enthalpy is the amount of energy absorbed by the reaction; in exothermic reactions, it is the amount given off. See also thermodynamics. |