  Through experimental investigation into the behaviour of a polar dielectric
working fluid, an ideal quasi-thermodynamic cycle has been established.
Particular stages of this cycle are described in terms of a condensed-matter
analogue of the false vacuum, when operating under negative-pressure. The cycle
is established between 37 degC and 15 degC under isochoric conditions.
Phase-change work is created in two-directions, positive expansion-work and
negative contraction-work. A large proportion of the expansion-work derives
from a cooling process where the fluid exhibits negative heat capacity. When
heat flux ceases, the fluid becomes unstable and heat capacity switches from
negative to positive, displaying a non-equivalence of ensembles phase-change.
  Whilst elements of the fluid behaviour can only be described by the
statistical mechanics of non-equilibrium systems, the calculated equations of
state for classical thermodynamics are confirmed to be accurate from the
experimental investigation. However, the classical thermodynamic calculations
for cycle-efficiency do not produce a symmetry of energy conservation. This
suggests that an additional form of energy, having long-range interaction and
distinct from heat and work input, is involved in the performance of the
quasi-thermodynamic cycle. The expansion of a negative-pressure fluid that
contains inclusion compounds appears responsible for this potential energy
interaction as an analogue of the false vacuum potential that can be explained
by application of the virial theorem.
