In thermodynamics, Joseph Henry Keenan (1900-1977) was an American mechanical engineer noted for his 1941 textbook Thermodynamics and his 1965 expanded textbook Principles of General Thermodynamics, co-written with George Hatsopoulos. [1] Keenan was a central founder of the MIT school of thermodynamics.

Influence | Students
Keenan’s 1941 textbook was influential to Polish-born American mechanical engineer Joseph Kestin. Italian thermodynamicist Gian Beretta is under the view that Keenan's 1965 textbook is the greatest thermodynamics book of the 20th century. A noted economics thermodynamics student of Keenan was Lithuanian-born Brazilian metallurgical-nuclear engineer, physicist, and thermodynamicist Borisas Cimbleris.

Law of stable equilibrium
Hatsopoulos and Keenan are known for their 1962 attempt to reduce the first law, second law, and state principle into one law, which they have called the law of stable equilibrium. [4] This principle states that:
 Law of stable equilibrium diagram. [4]

“A system having specified allowed states and an upper bound in volume can reach from any given state one and only one stable state and leave no net effect on its environment.”

This has been restated as: [5]

“When an isolated system performs a process, after the removal of a series of internal constraints, it will always reach a unique state of equilibrium; this state of equilibrium is independent of the order in which the constraints are removed and is characterized by a maximum value of entropy.”

Keenan school of thermodynamics
Between 1834 and 1961, Keenan was a professor and later head of the department of mechanical engineering at the Massachusetts Institute of Technology (MIT), and while there he established what has been come to be known as the "Keenan School of Thermodynamics”. [2] This, in effect, seemed to have largely founded what has become known nowadays as the MIT school of thermodynamics, added on to by the work of others.

Keenan is known for his calculation of steam tables, research in jet-rocket propulsion, and his work in furthering the understanding of the laws of thermodynamics. His classic 1941 textbook Thermodynamics served as a fundamental teaching tool in various engineering curricula during the 1940s and 1950s.
Keenan brought to the mechanical engineering profession the fundamental work of Willard Gibbs.

The faculty of MIT, during the summer session of 1953, under the guidance of Keenan, organized a Rumford summer school of thermodynamics in celebration of Count Rumford (Benjamin Thomson) Bicentennial: During Summer Session 1953, from Monday, June 29, to Friday, July 10, Inclusive. [3]

Notables associated this school include George Hatsopoulos and Gian-Paolo Beretta, the latter of which states that he ran a “thermodynamics think tank” at MIT in the late 1990s. The website QuantumThermodynamics.org, run by Beretta, lists publications by members of the “Keenan school of thermodynamics”.

References
1. Keenan, Joseph H. (1941). Thermodynamics. New York: John Wiley & Sons, Inc.
2. Selected publications on Quantum Thermodynamics – Gian-Paolo Beretta.
3. By Rumford Summer School of Thermodynamics (Massachusetts Institute of Technology, Published by Massachusetts Institute of Technology, 1953.
4. (a) Hatsopoulos, G. N. and Keenan, J.H. (1962). “A Single Axiom for Classical Thermodynamics”, J. Appl. Mech., A.S.M.E., 29, pgs. 193-99.
(b) Hatsopoulos, George N. and Keenan, Joseph H. (1965). Principles of General Thermodynamics (Law of stable equilibrium, pgs. xxviii, 367). New York: John Wiley & Sons, Inc.
(c) Perrot, Pierre. (1998). A to Z of Thermodynamics (pg. 248). Oxford: Oxford University Press.
5. Schneider, Eric D. and Sagan, Dorion. (2005). Into the Cool - Energy Flow, Thermodynamics, and Life (pg. 75). Chicago: The University of Chicago Press.