For example the word "lake" is a common noun. Yet the common noun "lake" can be part of a proper noun. For example the Great Salt Lake, Utah Lake, Sevier Lake, and Rush Lake.
When looking at the noun "stress" the same thing does not appear to happen. For example the Kirchhoff stress, the Biot stress and the Jaumann stress for a few examples. Why is the "stress" component of the examples above not capitalized? Are they not part of a proper noun?
Even more confusing is the "nominal stress", where neither words are capitalized. Am I correct in thinking that the above examples are not proper nouns but are capitalized as they are named after people? If so are they classified as common nouns?