Sustainability of small reservoirs and large scale water availability under current conditions and climate change

Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts of small reservoirs are subject to climate change. Using a case-study on North-East Brazil, this paper shows that climate change impacts on water availability may be severe, and impacts on distributed water availability from small reservoirs may exceed impacts on centralised water availability from large reservoirs. Next, the paper shows that the effect of small reservoirs on water availability from large reservoirs may be significant, and increase both in relative and absolute sense under unfavourable climate change

Limits to sustained energy intake. XXIII. Does heat dissipation capacity limit the energy budget of lactating bank voles?

Acknowledgements We are grateful to our technicians and several students for their help during this study and for animal care. We thank Catherine Hambly and Peter Thompson for technical assistance for the isotope analysis for the DLW measurements. We thank Ulf Bauchinger for stimulating discussion and his comments, and two anonymous referees for comments on the manuscript. Funding This project was supported by grants from the Polish Ministry of Science and Higher Education [0595/B/P01/2011/40 to E.T.S. and 8167/B/P01/2011/40 to P.K.], and Jagiellonian University [DS/WBINOZ/INOS/757 to P.K.].Peer reviewedPublisher PD

Team PhyPA: Brain-Computer Interfacing for Everyday Human-Computer Interaction

Brain-computer interfaces can provide an input channel from humans to computers that depends only on brain activity, bypassing traditional means of communication and interaction. This input channel can be used to send explicit commands, but also to provide implicit input to the computer. As such, the computer can obtain information about its user that not only bypasses, but also goes beyond what can be communicated using traditional means. In this form, implicit input can potentially provide significant improvements to human-computer interaction. This paper describes a selection of work done by Team PhyPA (Physiological Parameters for Adaptation) at the Technische Universität Berlin to use brain-computer interfacing to enrich human-computer interaction

2s exciton-polariton revealed in an external magnetic field

We demonstrate the existence of the excited state of an exciton-polariton in a semiconductor microcavity. The strong coupling of the quantum well heavy-hole exciton in an excited 2s state to the cavity photon is observed in non-zero magnetic field due to surprisingly fast increase of Rabi energy of the 2s exciton-polariton in magnetic field. This effect is explained by a strong modification of the wave-function of the relative electron-hole motion for the 2s exciton state.Comment: 5 pages, 5 figure

Radial Distribution of Particle Clusters in Down Flow Reactors

Particle clustering is of major importance in down flow reactors having a profound influence on some fundamental properties of the flowing suspension such as particle slip velocity. The goal of this study is to provide further evidence to support the formation of clusters using the novel CREC-GS-Optiprobes. This sensor is equipped with GRIN lenses and introduces minimum intrusion effects. Results reported include radial distributions of particle cluster size and velocity under various gas flow superficial velocities and suspension densities. Micro-scale and macro-scale flow structures are advanced on the basis of the reported data

Photocurrent Enhancement by Spontaneous Formation of a p n Junction in Calcium Doped Bismuth Vanadate Photoelectrodes

The application of bismuth vanadate BiVO4 photoelectrodes for solar water splitting is hindered by the poor carrier transport. To overcome this, multiple donor doping strategies e.g. dual doping, gradient doping have been explored. Here, we show for the first time the successful introduction of calcium Ca as an acceptor type dopant into BiVO4 photoelectrodes. Interestingly, instead of generating cathodic photocurrents, the Ca doped BiVO4 photoelectrodes show anodic photocurrents with an enhanced carrier separation efficiency. Hard X ray photoelectron spectroscopy HAXPES shows that this enhancement is caused by out diffusion of Ca during the deposition process, which spontaneously creates a p n junction within the BiVO4 layer. Overall, a significant two fold improvement of the AM1.5 photocurrent is obtained upon Ca doping. This study highlights the importance of controlled doping beyond simply modifying carrier concentration and may enable new device architectures in photoelectrode material