| Acronym | Meaning |
| EWPCA | European Water Pollution Control Association |
| UEBS | Unitarized Eikonal Born Series (in Electron-atom Scattering) |
| POA | Preoptic Area |
| PLI | Process Loading Intensity (of Biological Reactors) |
| CVD | Chemical Vapor Deposition |
| AES | Auger Electron Spectroscopy |
| LDA | Linear Diode Array |
| ORFEUS | Orbiting Retrievable Far And Extreme Ultraviolet Spectrometers |
| PDM3.1 | Probabilistic Dilution Model Version 3.1 |
| PEM | Performance Evaluation Material |