Second law of thermodynamics
The second law of thermodynamics may be expressed in many specific ways, the most prominent classical statements being the statement by Rudolf Clausius (1854), the statement by Lord Kelvin (1851), and the statement in axiomatic thermodynamics by Constantin Carathéodory (1909). These statements cast the law in general physical terms citing the impossibility of certain processes. The Clausius and the Kelvin statements have been shown to be equivalent.
Joseph Henry Keenan
Joseph Henry Keenan (August 24, 1900 – July 17, 1977) was an American thermodynamicist and mechanical engineer noted for his work in the calculation of steam tables, research in jet-rocket propulsion, and his work in furthering the development in the understanding of the laws of thermodynamics in the mid 20th century. His classic 1941 textbook "Thermodynamics" served as a fundamental teaching tool in various engineering curricula during the 1940s and 1950s.