One of the nice features of SciTech Connect is the ability to filter search results by subject and author. On the Search Results page, these filters are midway down the left side.
The full SciTech Connect database contains over 2.5 million citations. Filtering the full database by subject [23 MB AVI] shows the top subject in the database to be materials science with 184,200 citations. Not too far down the top ten list you will also find materials with another 127,916 citations. While this shows that SciTech Connect is quite strong in this area, the rest of the top subjects are good indicators of the diversity of scientific disciplines found in SciTech Connect. Note especially environmental sciences as the ninth most frequent subject term.
Selecting the Electronic Full-Text tab and filtering by subject [18 MB AVI] will give you a significantly different list of top ten subjects. Materials science is still high on the list, along with design and environmental sciences, but the other seven subjects are new.