Camote

Challcy, J. F. (1971). Camot, Nicolas Leonard Sadi . In Dictionary of Scientific Biography, Vol. 3, ed. Charles Coulston Gillispie. New York Scribner. 

In comparison the theoretical efficiency of a conventional combustion engine is limited by the Camot-cycle efficiency. This efficiency (Equation 6.5) is a function of the operating temperature (T2) and the temperature of the surroundings (Ti). 

Fluorine Dating. Probably the oldest scientific dating technique is fluorine dating, which, although seldom used today, is discussed here because of its historic interest. Fluorine dating of bone centers on an irreversible process whereby the inorganic component of buried bone is slowly and gradually, transformed into a more stable compound (see Textbox 67) (Camot 1893 Middleton 1845). 

Comprehensive discussions of fuel cells and Camot engines Nemst law analytical fuel cell modeling reversible losses and Nemst loss and irreversible losses, multistage oxidation, and equipartition of driving forces. Includes new developments and applications of fuel cells in trigeneration systems coal/biomass fuel cell systems indirect carbon fuel cells and direct carbon fuel cells. 

The Camot engine is a device by which a working substance can exchange mechanical work with its surroundings and can exchange heat with two heat reservoirs. 

Figure 6.3. Camot cycle temperature-volume diagram.

TABLE 6.1. Coupling of Two Camot Cycles with Different Efficiencies... 

Carnot stated that the efficiency of a reversible Camot engine depends only on the temperatures of the heat reservoirs and is independent of the nature of the working substance. This theorem can be proved by showing that the assumption of a reversible engine with any but the known efficiency of a reversible Camot engine leads to a contradiction of the Clausius statement of the second law. 

Figure 6.4. Scheme of two Camot engines, one acting as a heat engine and the other as a... 

The relationship between the thermodynamic temperature scale and the ideal gas temperature scale can be derived by calculating the thermodynamic quantities for a Camot cycle with an ideal gas as the working substance. Eor this purpose, we shall use 0 to represent the ideal gas temperamre. 

As the efficiency of a Camot engine is independent of the working substance, the efficiency given in Equation (6.42) for an ideal gas must be equal to that given in Equation (6.29) for any reversible Camot engine operating between the same heat reservoirs. Thus,... 

We can do this by examining the small Camot cycles in more detail. For example, for the cycle labeled a, we can state definitely, because the adiabatic steps contribute nothing to DQ/T, that... 

A better approximation to the actual cycle of Figure 6.5(a) would be a larger number of Camot cycles in Figure 6.5(h). In each such approximation. Equation (6.61) would be valid, but as the number of cycles used for the approximation is increased, the area BACB becomes smaller and smaller. In the limit of an... 

Figure 6.9. Gibbs temperature-entropy diagram for a Camot cycle.

Show that the efficiency of a Carnot cycle in which any step is carried out irreversibly cannot be greater than that of a reversible Camot cycle. 

The equality sign is reached for a reversible process, entailing overall zero entropy production. Concomitantly, efficiency will be below Camot in the presence of dissipative entropy producing fluxes. While this statement is strictly speaking correct, we will show below that it can be misleading. The delicate... 

Thermal Brownian motors can function as a motor, a heat pump, and a refrigerator. But can they reach Camot efficiency As we explained in some detail above, arguments have been raised against this possibihty [11-17]. On the other hand, a number of alternative constructions have been proposed for which it is claimed that Camot efficiency can be reached [24—29]. 

Plate 4. Sweet potato. The roots of Ipomoea batatas, known in Mexico as camote camohtli in... 

Schematic representation of (a) Carnot heat engine and (b) Camot refrigerator used as a heat pump. 

Figure 4.3 Reversible Camot cycle, showing steps (1) reversible isothermal expansion at th (2) reversible adiabatic expansion and cooling from th to tc (3) reversible isothermal compression at tc (4) reversible adiabatic compression and heating back to the original starting point. The total area of the Camot cycle, P dV, is the net useful work w performed in the cyclic process (see text).

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