Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4871702 | Ammonium activation of zeolites in the presence of gaseous ammonia | Clarence D. Chang, Cynthia T-W. Chu, Randall D. Partridge | 1989-10-03 |
| 4837398 | Ammonium activation of zeolites in the presence of gaseous ammonia | Clarence D. Chang, Cynthia T-W. Chu | 1989-06-06 |