Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6128916 | Membrane technology to remove non-condensable gases from refrigeration systems | Richard Alan Callahan | 2000-10-10 |
| 5693121 | Semi-permeable membrane separation process for the production of very high purity nitrogen | Richard Alan Callahan | 1997-12-02 |