| Acronym | Meaning |
| NTU | Nephelometric Turbidity Unit |
| TEWI | Total Equivalent Warming Impact |
| GTO | Gaussian-type Orbital |
| WET | Whole Effluent Toxicity |
| PB | Particle Beam |
| ORU | In Orbit Replaceable Unit (spacecraft) |
| AIMP | Ab Initio Model Potential (for Valence-electron Mol. Calcns.) |
| DQC | Double Quantum Coherence |
| ORSTB | Overlap-reduced Semiempirical Tight-binding |
| ARM | Atmospheric Radiation Measurement |