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We use a linear transmission technique to measure total cross sections for positron scattering from benzene, cyclohexane, and aniline. In the case of cyclohexane, the energy range of the present study is 0.1-20 eV, while for benzene and aniline it is 0.2-20 eV. With respect to benzene and cyclohexane, comparison is made to the only other existing results we know of ͓Makochekanwa and co-workers, Phys. Rev. A 68, 032707 ͑2003͒; 72, 042705 ͑2005͔͒. Agreement with those data is only marginal, being particularly poor at the overlap lower energies. Unlike Kimura et al. ͓J. Phys. B 37, 1461 ͑2004͔͒, we find the low-energy dependence of the positron-benzene total cross sections to be qualitatively similar to those found in the electron channel ͓Gulley et al., J. Phys. B 31, 2735 ͑1998͔͒. We believe that the present positron-aniline total cross sections represent the first time such data have been measured. These cross sections are almost identical to those we found for benzene, suggesting that substitution of hydrogen by the amine group on the aromatic ring is largely irrelevant to the scattering process in the energy regimes considered.

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Two new types of connections for photovoltaic cells in dense array are presented. These connections, making use of dc–dc converter modules, are shown to increase the power transfer to the load with respect to array realized with series o parallel connections for the same number of cells. The present connections are of particular interest in concentration photovoltaic (CPV) systems where the intensity of the incident light on each cell of the array can be very different causing the cells of the same array working with different current–voltage (I–V) curves. The two types of connection and the classical series and parallel connections are compared on a theoretical basis. Applications of the connections in real working scenarios are illustrated and discussed. Copyright © 2010 John Wiley & Sons, Ltd.