MRI of a knee. MRIs employ powerful magnets which produce a strong magnetic field that forces protons in the body to align with that field. When a radiofrequency current is then pulsed through the patient, the protons are stimulated, and spin out of equilibrium, straining against the pull of the magnetic field.
Noun. 1. aestivation - (zoology) cessation or slowing of activity during the summer; especially slowing of metabolism in some animals during a hot or dry period. estivation. zoological science, zoology-the branch of biology that studies animals.
passivated. 1  transitive verb. 2  1 : to make inactive or less reactive passivate the surface of steel by chemical treatment. 3  2 : to protect (something, such as a solid-state device) against contamination by coating or surface treatment.