Dendrimers have been previously shown to provide significant advantages in both excited-state energy transfer and charge transfer. However, this architecture causes one of the charges to be encapsulated and thus not available for charge separation over long distances. We conceived dendron-rod-coils as scaffolds that could have the architectural advantage of the dendrimers, while still providing...

background: it has been claimed that by using different washing methods, the sperms can be separated according to size, motility, density, chromosomal content and surface markings and charge. these methods also reduce sperm chromatin deficiencies and screen the sperms before applying in assisted reproduction techniques. objective: this study compared simple density gradient methods and a combin...

An analysis is made of the charge distribution in a quasi-static thundercloud system with the assumptions that (1) the cloud has a charge separation mechanism at its midpoint and ( 2 ) the conductivity within the cloud is reduced by a given fraction from the free-air conductivity remote from the storm. The charge separation mechanism produces the primary positive dipole of the storm. The analys...

The electron-hole pair created via photon absorption in organic photoconversion systems must overcome the Coulomb attraction to achieve long-range charge separation. We show that this process is facilitated through the formation of excited, delocalized band states. In our experiments on organic photovoltaic cells, these states were accessed for a short time (<1 picosecond) via infrared (IR) opt...

The phase diagram of the copper-oxide chain as a function of density and the nearest-neighbour Coulomb interaction, V , is determined. Phase separation takes place above a critical value of V when the Cu 2+ → Cu + valence fluctuations dominate. In the proximity of the phase separation boundary the superconducting correlations are the most divergent. We identify the parameter regions where the L...