| Acronym | Meaning |
| MSX | Midcourse Space Experiment |
| TPPI | Time Proportional Phase Increment |
| SACF | Symmetry-adapted Configuration Function |
| DSITMS | Direct Sampling Ion Trap Mass Spectrometry |
| CID | Collision-induced Dissociation |
| BTE | Boltzmann Transport Equation |
| PEN | Personal Electronic Notebook |
| PFRP | Process To Further Reduce Pathogens |
| PROM | Programmable Read-only Memory |
| ASM | Advanced Scavenging Model (for Air Pollution) |