This maintains the heat transfer between steam and liquid to a maximum. Figure 3 shows a temperature profile when saturated steam is used. The difference with the previous diagram is that there is now a layer of condensate on the heating surface and steam temperature is constant.
As a general rule Owls are monogamous - pairs are comprised of one male and one female, neither one of which has any involvement with other nesting birds. With some Owl species the pair bonds last only for the duration of the breeding season, especially if the species involved is dispersive or migratory.
Trumpeter Swans form pair bonds when they are three or four years old. The pair stays together throughout the year, moving together in migratory populations. Trumpeters are assumed to mate for life, but some individuals do switch mates over their lifetimes. Some males that lost their mates did not mate again.