mesostate

From meso- +‎ state. Sense 4 possibly purely in analogy with anastate and catastate.

mesostate (plural mesostates)

1. (physics) An intermediate physical state of matter between solid and liquid, in which the molecules have more freedom of movement than when locked in a crystal lattice, but less freedom of movement than when in the liquid state.
   • 1974, Russian Journal of Physical Chemistry - Volume 48, page 896:

     […] the liquid to the solid state via first-order phase transformations, which must be preceded by a breakdown of the structure of the mesostate—an intermediate state of the alum in its transition from the solution to the crystaline phase.

   • 1989, Cornel K. Pokorny, Curtis F. Gerald, Computer Graphics: The Principles Behind the Art and Science:

     Many substances can be in a state between crystallized and liquid. This means that the molecules have more freedom of motion than in the solid state but not as much as in a liquid, a condition called mesostate.

2. (thermodynamics) A composite state of a physical system that is determined by the overall configuration of many microstates; e.g. the heat of a substance (mesostate), which is made up of the aggregate of motions of many molecules (microstate).
   • 2021, Luca Peliti, Simone Pigolotti, Stochastic Thermodynamics: An Introduction, page 42:

     If the manipulation is slow enough, and the driving connects different mesostates, then jumps between states in the same mesostate satisfy the detailed balance condition.

   • 2022, Philipp Strasberg, Quantum Stochastic Thermodynamics, page 51:

     Even though we said the mesostates x are relatively stable, after a very long time they will also eventually thermalize (unless we additionally protect them).

   • 2023, Miranda Louwerse, Efficient Control and Spontaneous Transitions, page 31:

     For systems with metastable conformations, a trajectory initiated in one mesostate spends a (potentially) long time sampling microstates in that mesostate before overcoming the energy barrier to sample the other mesostate, and due to the timescale separateion between the simulation timestep and reaction transitions, it becomes impractical to compute free energies via a brute-force approach.

3. (geography) A description of an aspect of a geographical system at a level between complete detail (the microstate) and a simple summary statistic or percentage (the macrostate).
   • 1978, Stephen H. Putman, “The Integrated Forecasting of Transportation and Land Use”, in William Frederick Brown, editor, Seminar on Emerging Transportation Planning Methods:

     In operational urban simulation models, virtually no attempt is made to simulate at the level of microstates, i.e., individual behavior. Most of the models operate at the mesostate and/or macrostate level.

   • 1980, Meir Gross, “The Lowry Model of Land Use Simulation and Its Derivatives”, in Models in Urban Geography Part -ii, page 501:

     Given a microstate description of a system, only one mesostate is possible; and given a mesostate description, only one macrostate is possible: in both cases the higher level description can be found by simple summation ( see Equations 8,3,4) .

   • 2002, Eurasian Geography and Economics - Volume 43, page 381:

     For instance, in the first mesostate, the five female voters can only be allocated one way: all voted for a party other than the PDS. Each one of the four males, however, could have voted for a non-PDS party. Therefore, there are a total of four microstates associated with the first mesostate.

4. (biology, rare) An intermediate metabolic product in the formation of anastates or catastates.
   • 1885, Sir Michael Foster, A Text-book of physiology, page 336:

     In this downward parth are probably many steps, two of which become conspicuous, the formation of some intermediate product to "mesostate," as we may call it, such as zymogen or mucigen, and the conversion of the zymogen into an actual ferment or of the mucigen into mucin — that is, of the mesostate into the final product, which is discharged as a constituent of the secretion.

   • 1887, Conwy Lloyd Morgan, Animal Biology, page 191:

     But it is probable that here too, by the vital activity of the protoplasmic element in each cell, there is produced a mesostate which, at the moment of activity, passes by katabolism into waste products, so called, of a less complex composition.

• mesostasis