1,010 research outputs found
The HELP inequality on trees
We establish analogues of Hardy and Littlewood's integro-differential equation for Schrödinger-type operators on metric and discrete trees, based on a generalised strong limit-point property of the graph Laplacian
Polyaniline-silver hybrid materials for ink-jet printing
The synthesis of PANI/Ag hybrid materials has been carried out via a rapid chemical oxidative, in-situ polymerisation method, using silver nitrate and ammonium peroxydisulfate as oxidant precursors. These species react together to produce Ag2+, an oxidising intermediate which has greater oxidising power than either persulphate or Ag+ alone. The reaction thus proceeds at a much accelerated rate than that of pure PANI, approximately 6 times faster. Various characterisation techniques were used to characterise this new hybrid material, PANI-Ag. UV-vis absorption spectroscopy was used to follow the formation of polymer over time and monitor the rate at which the reaction progresses for both PANI and PANI-silver. It is evident from the absorption spectra that the polymer forms via the fully-oxidised pernigraniline state initially, before reducing back into the more stable emeraldine salt form. This process is significantly accelerated using both APS and AgNO3, as opposed to when using APS or AgNO3 alone. These new composites could potentially find use as functional materials for the printed electronics industry where new processable, hybrid materials as required for applications in sensing, memory, logic and photovoltaics
UK Giving 2012: an Overview of Charitable Giving in the UK, 2011-12
The UK Giving survey provides the latest research on individuals' donations to charity -- how much is given, who the donors are, where the donations go, and the trends over time
Hot gas and dust in a protostellar cluster near W3(OH
We used the IRAM Interferometer to obtain sub-arcsecond resolution
observations of the high-mass star-forming region W3(OH) and its surroundings
at a frequency of 220 GHz. With the improved angular resolution, we distinguish
3 peaks in the thermal dust continuum emission originating from the hot core
region about 6 arcsec (0.06 pc) east of W3(OH). The dust emission peaks are
coincident with known radio continuum sources, one of which is of non-thermal
nature. The latter source is also at the center of expansion of a powerful
bipolar outflow observed in water maser emission. We determine the hot core
mass to be 15 solar masses based on the integrated dust continuum emission.
Simultaneously many molecular lines are detected allowing the analysis of the
temperature structure and the distribution of complex organic molecules in the
hot core. From HNCO lines, spanning a wide range of excitation, two 200 K
temperature peaks are found coincident with dust continuum emission peaks
suggesting embedded heating sources within them.Comment: 12 pages, 3 figure
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