Evaluation of canine cryopreserved semen has the ultimate goal of determining if an individual frozen ejaculate will have acceptable fertility. This is difficult in that there is no accepted normal fertility for the dog. The fertility of the female also plays a crucial role in estimating the fertility of the male. Poor female fertility can make a fertile male appear less fertile. Variability of...

Aims. We present a systematic theoretical study on 40 polycyclic aromatic hydrocarbons dications (PAHs ++) containing up to 66 carbon atoms. Methods. We performed our calculations using well established quantum–chemical techniques in the framework of the density functional theory (DFT) to obtain the electronic ground–state properties, and of the time–dependent DFT (TD–DFT) to evaluate the excit...