Beyond perfection, the field to be explored is too wide. In this context, several ways to classify imperfect graphs or, equivalently, 0, 1 (clique-node) imperfect matrices can be found in the literature. From the polyhedral point of view, ideal matrices are to set covering problems what perfect matrices are to set packing problems. In fact, if a matrix is ideal, its linear relaxation is an inte...

Calculation of phase and chemical equilibria is of fundamental importance for the design and simulation of chemical processes. Methods that minimize the Gibbs free energy provide equilibrium solutions that are only candidates for the true equilibrium solution. This is because the number and type of phases must be assumed before the Gibbs energy minimization problem can be formulated. The tangen...

Matter of subnuclear density in the inner crusts of neutron stars consists of neutron-rich atomic nuclei immersed in strongly degenerate relativistic gas of electrons and strongly nonideal liquid of neutrons. Thermodynamic and kinetic properties of this matter are greatly affected by Coulomb and nuclear interactions and can be studied, in principle, from observations of thermal radiation of you...