CLAPEYRON

FRANCE (see also List of Individuals)

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26.2.1799 Paris/F - 28.1.1864 Paris/F

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Benoît-Paul-Emile Clapeyron was both a physicist and an engineer. He graduated in 1818 from Ecole Polytechnique as a mining engineer. He moved then for ten years to Saint Petersburg, Russia, as a professor of mathematics at the Public Works School. Upon returning to France after the 1830 revolution he noted great interest in railroads. Economic failures suggested that the process of heat transformation needed a detailed engineering study. After Clapeyron had in vain tried to found a railroad company, he contributed to railway design with a notable bridge over Seine River. Clapeyron was in 1844 appointed professor at the Ecole des Ponts et Chaussées and in 1848 elected to the Academy of Sciences, Paris. He was a committee member for the Suez Canal works and for the use of steam engines in the navy.

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In 1834 Clapeyron discovered the 1824 paper of Sadi Carnot (1796-1832) relating to the second law of thermodynamics and diffused Carnot's ideas. Interest aroused only some ten years later with a contribution of the German Robert Mayer. Clapeyron's name is remembered particularly for his explanation of the thermal phenomena of gas and vapors. He noted that it was important to consider the "fundamental axiom" of Carnot, according to which it is impossible to create from zero neither heat nor work. Also, he noted that heat can generate work, or vice-versa, although these processes are always accompanied with a loss of energy. Clapeyron then developed a graphical method allowing for the prediction of these processes for a specific pressure and gas volume. The Clapeyron equation determines the heat vaporization of a liquid.

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_{Anonymous (1897). Clapeyron. Livre du centenaire 1794-1894: Ecole Polytechnique 1: 194-}

_{198. Gauthier-Villars: Paris.}

_{Anonymous (1939). Clapeyron, Benoît-Paul-Emile. Index biographique des membres et correspondants de l'Académie des Sciences de 1666 à 1939: 104. Gauthier-Villars: Paris.}

_{Bellone, E. (1975). Clapeyron, Benoît-Paul-Emile. Scienziati e tecnologi 1: 316-318.}

_{Mondadori: Milano. P}

_{Cardwell, D.S.L. (1974). Les débuts de la thermodynamique. La Recherche 48(9): 726-749. Clapeyron, E. (1833). Note sur un théorème de mécanique. Annales des Mines Série 3: 63-70. Clapeyron, E. (1834). Mémoire sur la puissance motrice de la chaleur. Journal de l'Ecole Polytechnique 14: 153-190.}

_{Thomson, W. (1852). Mémoires sur la théorie physique de la chaleur. Annales de Chimie et de Physique 35: 118-124, also in Trans. Royal Society Edinburgh 20 (1853): 261-283.}