isochore

From iso- +‎ Ancient Greek χώρα (khṓra, “place”).

isochore (plural isochores)

1. (physics) A line drawn on a pressure / volume / temperature graph through all points having the same value of the volume.
   • 1916, William Cudmore McCullagh Lewis, A System of physical chemistry, volume 1, page 92:

     An isochore is a curve on a PVT diagram, the pressure and temperature being variable, the volume invariable.

   • 1956, Enrico Fermi, Thermodynamics, page 7:

     Thus, an isochore transformation in this case is a transformation at constant volume.

   • 1992, J M Yeomans, Statistical Mechanics of Phase Transitions, page 2:

     1.3 shows the specific heat of argon measured along the critical isochore.

2. (geology) A contour showing points of equal vertical thickness of strata; equal to an isopach if strata are horizontal.
   • 1964, Mineral Development in Assam: Symposium Volume, Assam (India) Directorate of Geology and Mining, page 205:

     The isochore plan of the overburden thus obtained is then placed over the isochore plan of the seam.

   • 1981, Coalfields of India, Geological Survey of India, page 125:

     Isochore maps of the sandstone bodies also indicate the presence of a number of channels flowing from the basin margin towards a central depression.

3. (genetics) A sequence of DNA that has a reasonably constant proportion of pairs of guanine and cytosine bases, and is rich in genes.
   • 1998, Lindsey R Lindsey; Alan R Lindsey, Transgenic Plant Research, page 268:

     A model that accounts for the differential recognition of transgenes integrated at different chromosomal locations, is the isochore hypothesis.

   • 1999, Solomon Pavlovich Vasser; Eviatar Nevo, “Scheme of the isochore organization of the human genome”, in Evolutionary Theory and Processes: Papers in Honour of Eviatar Nevo, page 117:

• choosier