15,118 research outputs found
Giant Fluctuations of Coulomb Drag in a Bilayer System
We have observed reproducible fluctuations of the Coulomb drag, both as a
function of magnetic field and electron concentration, which are a
manifestation of quantum interference of electrons in the layers. At low
temperatures the fluctuations exceed the average drag, giving rise to random
changes of the sign of the drag. The fluctuations are found to be much larger
than previously expected, and we propose a model which explains their
enhancement by considering fluctuations of local electron properties.Comment: 10 pages, 4 figure
Some Empirical Criteria for Attributing Creativity to a Computer Program
Peer reviewedPostprin
The limitations of speech control: perceptions of provision of speech-driven environmental controls
This study set out to collect data from assistive technology professionals about their provision of speech-driven environmental control systems. This study is part of a larger study looking at developing a new speech-driven environmental control system
Shot Noise in Mesoscopic Transport Through Localised States
We show that shot noise can be used for studies of hopping and resonant
tunnelling between localised electron states. In hopping via several states,
shot noise is seen to be suppressed compared with its classical Poisson value
( is the average current) and the suppression depends on the
distribution of the barriers between the localised states. In resonant
tunnelling through a single impurity an enhancement of shot noise is observed.
It has been established, both theoretically and experimentally, that a
considerable increase of noise occurs due to Coulomb interaction between two
resonant tunnelling channels.Comment: 7 pages, 5 figures; Proceedings of the 10th Conference on Hopping and
Related Phenomena (Trieste 2003); requires Wiley style files (included
Bell-inequality violation with a triggered photon-pair source
Here we demonstrate, for the first time, violation of Bell's inequality using
a triggered quantum dot photon-pair source without post-selection. Furthermore,
the fidelity to the expected Bell state can be increased above 90% using
temporal gating to reject photons emitted at times when collection of
uncorrelated light is more probable. A direct measurement of a CHSH Bell
inequality is made showing a clear violation, highlighting that a quantum dot
entangled photon source is suitable for communication exploiting non-local
quantum correlations.Comment: 14 pages, 4 figure
Pregnant Sheep in a Farm Environment Did Not Develop Anaemia
The aim of this study was to document the haematological profile of pregnant ewes throughout gestation. Sheep were divided into three groups (n = 8 per group): non-pregnant, singleton, or twin pregnancy. Blood samples were collected every 14 days from day 55 of gestation for haemoglobin concentration; packed cell volume; total protein; and albumin concentration. On days 55 and 125 of gestation blood was collected for trace element estimation: soluble copper and zinc; glutathione peroxidase (GSHPx); and methylmalonic acid (MMA). Pooled faecal samples were collected on days 55, 97, and 139 of gestation. Pasture cuts were collected on days 97 and 153 of gestation. The haematology and protein concentrations were not different between groups throughout the study. Copper concentration increased in all animals during the study (p < 0.0001). Zinc concentration was lowest in the singleton and twin pregnant sheep on day 55 of gestation (p = 0.04). GSHPx was not different between groups during the study. MMA decreased in all animals during the study (p < 0.0001), but was not different between groups. Faecal samples were consistently negative for strongyle and nematode eggs, and coccidian oocysts. The pasture was good quality. Pregnant sheep in a farm environment with normal trace element status, no parasites, and an adequate diet, did not develop anaemia (PCV < 0.27)
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UK Research Information Shared Service (UKRISS) Final Report, July 2014
The reporting of research information is a complex and expensive activity for research organisations (ROs). There is little alignment between funders of the reporting requests made to institutions and requests made to individual researchers about their research outputs and outcomes. This inevitably results in duplication and increased costs across the sector, whilst limiting the potential sharing and reuse of the information. The UK Research Information Shared Service (UKRISS) project conducted a feasibility and scoping study for the reporting of research information at a national level based on CERIF (Common European Research Information Format), with the objective of increasing efficiency, productivity and quality across the sector. The aim was to define and prototype solutions which are compelling, easy to use, have a low entry barrier, and support innovative information sharing and benchmarking. CERIF has emerged as the preferred format for expressing research information across Europe. To date, CERIF has been piloted for specific applications, but not as a format for reporting requirements across all UK ROs. The final report presents the work carried out by the UKRISS project, including requirements gathering, modelling and prototyping, as well as recommendation for sustainability. UKRISS was divided into two phases. Phase 1, mapping the reporting landscape, ran from March 2012 to December 2012. Phase 2, exploring delivery of potential solutions, began in February 2013 and ended in December 2013
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