| Acronym | Meaning |
| IEM | Independent Electron Model (for Ionization In Ion-atom Collisions) |
| OFA | Oil Fly Ash |
| ICAM | Integrated Climate Assessment Model |
| ILDA | Intensified Linear Diode Array |
| CD | Coulomb Dipole (in Electron-atom Impact Ionization Calcns.) |
| IFFE | Immune Free Flow Electrophoresis |
| OCE | One-center Expansion (SCF MO Method) |
| EBO | Equivalent Bond Orbital |
| AASD | Anaerobic Activated Sludge Digestion |
| TRXF | Total Reflection X-ray Fluorescence |