| Acronym | Meaning |
| PCS | Permit Compliance System |
| BEI | Biological Exposure Indices |
| PRENFLO | PRessurized ENtrained FLOw (process) [combustion And Gasification] |
| ARDS | Adult Respiratory Distress Syndrome |
| CCR | Close-coupled Representation |
| NRDC | Natural Resources Defense Council |
| FMO | Frontier Molecular Orbital |
| GDR | Giant Dipole Resonance |
| QCI | Quadratic Configuration Interaction |
| PIPES | Piperazine-1 |