Sr (Noun)

A soft silver-white or yellowish metallic element of the alkali metal group; turns yellow in air; occurs in celestite and strontianite.

Nouns denoting substances.

The doctor had to order an MRI scan to confirm that the bone tumor contained Sr.
After many attempts to refine the new Sr source for her project, Dr. Johnson succeeded.
Exposure to large quantities of Sr during radiation therapy requires monitoring to minimize potential damage to body tissue.
These data indicated the distribution and activity of the target in various areas by tagging with radioactive Sr.
Once researchers controlled for levels of strontium or Sr contamination in groundwater and human drinking supplies they moved forward.

The unit of solid angle adopted under the Systeme International d'Unites.

Nouns denoting quantities and units of measure.

The luminous intensity of the light source was measured in candelas per steradian.
A steradian is the unit of solid angle in three-dimensional space.
The formula for calculating the luminous flux in lumens per steradian is often used in optics.
In physics, a steradian is a unit of measurement that quantifies the angular span of a cone of light.
One steradian is defined as the solid angle subtended at the center of a sphere by a spherical cap.