| Acronym | Meaning |
| NLC | Noctilucent Cloud |
| ACL | Average Contaminant Level |
| CERPIES | Collision Energy Resolved Penning Ionization Electron Spectra |
| EPR | Ethylene-propylene Rubber |
| ITO | Indium Tin Oxide (gas Sensor |
| BKCM | Burkhardt-Konya-Coulson-March (for Electron Momentum Densities) |
| GRWA | Generalized Rotating-wave Approxn. (in Energy Level Calcns.) |
| ODC | Orientation Distribution Coeffs. |
| ND | Nitrification Denitrification |
| LTTS | Low-Temperature Thermal Separation (for Waste Soil Treatment) |