Experimental Investigation of Gas Dynamic Effects Using Nanoporous Synthetic Materials as Tight Rock Analogues

Transport in Porous Media - To improve the understanding of gas transport processes in tight rocks (e.g., shales), systematic flow tests with different gases were conducted on artificial micro- to...     

Novel approach to trans-fused carbobicycles

The combination of a silicon directed N-acyliminium ion cyclization reaction and a subsequent S_N2′ substitution of an imide nitrogen with lithium dimethyl cuprate constitutes a novel approach to functionalized transfused carbobicycles.     

Comparison of amorphous silicon solar cell performance following light and high-energy electron-beam induced degradation

In this article a comparison is reported between amorphous silicon (a-Si:H) solar cells that have been degraded using light soaking and 1 MeV electron-beam irradiation. Solar cells were degraded in open- and short-circuit condition, with the aim to change the recombination profile in the cell. For light-soaked solar cells a clear difference is found between open- and short-circuit conditions. Under open-circuit condition the solar cells degrade much more, which is explained by a much higher recombination rate under illumination in this case. These recombination events are believed to initiate defect formation. The performance of thin solar cells degrades less, as expected. For solar cells degraded under electron-beam irradiation no difference is found between open- and short-circuit conditions. Therefore we think that during electron-beam irradiation defect creation is not initiated by recombination events, but by energy transfer during collisions. The fill factor of thin solar cells degrades more after electron-beam irradiation. This effect is ascribed to a significant increase of the activation energy of the doped layers after irradiation.     

Self-trapped interstitial-type defects in iron

Small interstitial-type defects in iron with complex structures and very low mobilities are revealed by molecular dynamics simulations. The stability of these defect clusters formed by nonparallel {110} dumbbells is confirmed by density functional theory calculations, and it is shown to increase with increasing temperature due to large vibrational formation entropies. This new family of defects provides an explanation for the low mobility of clusters needed to account for experimental observations of microstructure evolution under irradiation at variance with the fast migration obtained from previous atomistic simulations for conventional self-interstitial clusters.