For many materials, the ratio of stress over strain is essentially constant over a range of strains.
On the time scale on which oscillates, is essentially a constant.
As with other jet engines, the combustor's job is to create hot air, by burning a fuel with the air at essentially constant pressure.
For most radioactive nuclides, the half-life depends solely on nuclear properties and is essentially a constant.
The contents are enclosed by the crock and the lid, and attain an essentially constant temperature.
A person in an elevator, with essentially constant visual input, will feel she is descending as the elevator starts to descend.
The condensation process occurs at essentially constant pressure.
The evaporator operates at essentially constant pressure.
Still, the Israeli approach shows how the country has come to deal with a danger that is essentially constant.
Distortion is essentially constant along lines of constant distance parallel to the ground track.