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.
Passivation is the process of making a material âpassiveâ, usually by the. deposition of a layer of oxide on its surface. In air, passivation affects. the properties of almost all metalsânotable examples being aluminium, zinc, titanium, and silicon. In the context of corrosion, passivation is the. spontaneous formation of a hard non-reactive surface film that inhibits.