A diacritic – also diacritical mark, diacritical point, diacritical sign from ancient Greek διά ( dia, through) and κρίνω ( krinein, to separate) – is a glyph added to a letter, or basic glyph. The term derives from the Greek διακριτικός ( diakritikós, "distinguishing"). Diacritic is primarily an adjective, though sometimes used as a noun, whereas diacritical is only ever an adjective. Some diacritical marks, such as the acute ( ´ ) and grave ( `&thins..
Thermodynamics is a branch of natural science concerned with heat and its relation to energy and work. It defines macroscopic variables (such as temperature, internal energy, entropy, and pressure) that characterize materials and radiation, and explains how they are related and by what laws they change with time. Thermodynamics describes the average behavior of very large numbers of microscopic constituents, and its laws can be derived from statistical mechanics.
