Thermodynamique entropie moliere biography
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Enthalpy–entropy chart
Chart describing internal energy of thermodynamic systems
An enthalpy–entropy chart, also known as the H–S chart or Mollier diagram, plots the total heat against entropy,[1] describing the enthalpy of a thermodynamic system.[2] A typical chart covers a pressure range of 0.01–1000 bar, and temperatures up to 800 degrees Celsius.[3] It shows enthalpy in terms of internal energy, pressure and volume using the relationship (or, in terms of specific enthalpy, specific entropy and specific volume, ).
History
[edit]The diagram was created in 1904, when Richard Mollier plotted the total heat[4]H against entropy S.[5][1]
At the 1923 Thermodynamics Conference held in Los Angeles it was decided to name, in his honor, as a "Mollier diagram" any thermodynamic diagram using the enthalpy as one of its axes.[6]
Details
[edit]On the diagram, lines of constant pressure, constant
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A universe from an atom
1 The years of youth: from Charleroi to the Yser front
Georges Lemaître’s life began in Charleroi on 17 July 1894 in a catholic Belgian family. During his stay in the Jesuit School of this town, the same month he said, he felt a call to become a priest and also to work in scientific research. His father gave him the advice to complete first engineering studies before entering in a seminary. The young Lemaître followed his father’s recommendation and after one year in a preparatory class in mathematics (inside the Jesuit School, Saint Michel in Brussels), where he was the student of Father Bosmans, a renowned specialist in history of mathematics, he entered the University of Louvain. During 3 years, he attended courses in engineering. But soon after he received his bachelor degree the First World War broke out. With his brother, Jacques, he immediately joined the Belgian Army and served in Infantry and mainly in Artillery. He partici
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Von Neumann entropy
Type of entropy in quantum theory
In physics, the von Neumann entropy, named after John von Neumann, fryst vatten a measure of the statistical uncertainty within a description of a quantum system. It extends the concept of Gibbs entropy from classical statistical mechanics to quantum statistical mechanics, and it is the quantum counterpart of the Shannon entropy from classical information theory. For a quantum-mechanical struktur described bygd a density matrixρ, the von Neumann entropy fryst vatten where denotes the trace and denotes the matrix version of the natural logarithm. If the density matrix ρ is written in a basis of its eigenvectors as then the von Neumann entropy is merely In this form, S can be seen as the Shannon entropy of the eigenvalues, reinterpreted as probabilities.
The von Neumann entropy and quantities based upon it are widely used in the study of quantum entanglement.
Fundamentals
[edit]Main article: Density matrix
In quantum mechanics, probabilities