| Acronym | Meaning |
| EFA | Envelope Function (i.e. |
| TOST | Turbine Oil Stability Test |
| QRIOSA | Quantum Reactive Infinite Order Sudden Approxn. |
| EPICA | European Project For Ice Coring In Antarctica |
| MSWI | Municipal Solid Waste Incinerator(s) |
| MIEHM | Modified Iterative Extended Hueckel Method |
| AQCR | Air Quality Control Region (US EPA) |
| NFT | Neurofibrillary Tangle |
| ENSO | El Nino Southern Oscillation |
| ITIES | Interface Between Two Immiscible Electrolyte Solutions |