| ofd | object-film distance |
|---|---|
| Rf | in paper or thin-layer chromatography, the distance that a spot of a substance has moved from the po... |
| Rst | in paper or thin layer chromatography, the distance that a spot of a substance has moved, relative t... |
| SAD | Scale of Anxiety and Depression; seasonal affective disorder; Self-Assessment Depression [scale]; se... |
| SFD | silo filler's disease; skin-film distance; small for dates; spectral frequency distribution |