The total heat developed by an ounce of zinc through its union with oxygen in the battery is also absolutely invariable.
The second is the actual heat efficiency, or the ratio of the heat turned into work to the total heat received by the engine.
From this it is clear that the larger proportion of total heat of the body is supplied by the muscles.
The quantity actually observed by Rowland was the total heat.
(b) When the resulting ice melts, is the total heat change the same or different from that of freezing?
Fully four-fifths of the total heat are used up in this molecular work, only one-fifth remaining to warm the battery.
The total expenditure of heat of a man at rest must be equal to the total heat of combustion.
Minimum thermal conductance occurs when total heat transfer through these layers is reduced to its lowest possible rate.
His next step was the discovery of the total heat of steam, and that this remains practically constant at all pressures.
The total heat of the steam remains nearly constant, whatever be the temperature at which the vaporization occurred.
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. |