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.
What is Chemical Passivation?Chemical passivation is a two step process. The ï¬rst step is to remove any free iron or iron compound that is on the surface, otherwise this iron will create a localized site where corrosion can continue. Acid is used to dissolve away the iron and its compounds.