Homogeneous and heterogeneous mixtures mixture is air. In physical chemistry and materials science this refers to substances and mixtures which are in a single phase. This is in contrast to a substance that is heterogeneous. A solution has been a special type of homogeneous mixture. Solutions are homogeneous because the ratio of solute to solvent remains the same throughout the solution even if homogenized with multiple sources, and stable because the solute will not settle out after any period of time, and it cannot be removed by a filter or by centrifuge. This type of mixture is very stable, i.e., its particles do not
Phase-type distribution (the non-homogeneous case). The mixture of two Erlang distribution with parameter "E"(3,β), "E"(3,β) and (α,α) (such that α + α = 1 and for each "i", α ≥ 0) can be represented as a phase type distribution with and The Coxian distribution is a generalisation of the hypoexponential distribution. Instead of only being able to enter the absorbing state from state "k" it can be reached from any phase. The phase-type representation is given by, and where 0 < "p"...,"p" ≤ 1. In the case where all "p" = 1 we have the hypoexponential distribution. The Coxian distribution is extremely