Quantitative models , based on topological indices and similar structural features , have been developed for the accurate calculation of 1-octanol/ water partition coefficiens of polycyclic aromatic hyrocarbons ( PAHs ) , their heteroanalogues with oxygen , nitrogen , and sulphur , their alkyl- , chloro- , amino- , and hydroxyl- derivatives , as well as for chlorinated benzenes and chlorinated biphenyls ( PCBs ) .
Vježbat ćemohrenWaC hrenWaC