text: Each process is one of the following:
  *isothermal (at constant temperature, maintained with heat added or removed from a heat source or sink)
  *isobaric (at constant pressure)
  *isometric/isochoric (at constant volume), also referred to as iso-volumetric
  *adiabatic (no heat is added or removed from the system during adiabatic process)
  *isentropic (reversible adiabatic process, no heat is added or removed during isentropic process)