65,745 research outputs found
Allocation of Carbon Emission Certificates in the Power Sector: How generators profit from grandfathered rights
To meet its Kyoto requirements, the EU will establish an internal market for carbon dioxide allowances from 2005, the EU Emissions Trading Scheme (ETS). National governments are to allocate most of these allowances for free. The analysis shows that as a result the net value of both a typical pulverised coal-fired (PC) power station and a more modern gas-fired combined cycle gas turbine (CCGT) will increase. We show that in future allocation rounds a greater proportion of allowances can and should be auctioned. The paper also analyses the interactions with the Large Combustion Plant Directive, which limits SO2 and NOx emissionselectricity generation, eu emission trading, allocation, updating, grandfathering
Static and Dynamic Pressure Distributions in a Short Labyrinth Seal
As part of a study into turbine blade tip destabilizing forces, a seals test rig was built in which spin rate, circular whirl rate, direction and amplitude of inlet swirl angle, and eccentricity can all be controlled over wide ranges, and measurements can be made at gap Reynolds numbers up to about 2 x 10(exp 4). This facility is described and preliminary data is presented for a one cavity labyrinth seal with a flat, stator mounted land. The impact of different flow coefficients for the first and second knives on the rotordynamic coefficients was found. While this effect is dominant for the direct forces, it should also be incorporated into calculations of cross forces where it has an impact under many conditions
Reflectance Transformation Imaging (RTI) System for Ancient Documentary Artefacts
This tutorial summarises our uses of reflectance transformation imaging in archaeological contexts. It introduces the UK AHRC funded project reflectance Transformation Imaging for Anciant Documentary Artefacts and demonstrates imaging methodologies
Kruskal coordinates as canonical variables for Schwarzschild black holes
We derive a transformation from the usual ADM metric-extrinsic curvature
variables on the phase space of Schwarzschild black holes, to new canonical
variables which have the interpretation of Kruskal coordinates. We explicitly
show that this transformation is non-singular, even at the horizon. The
constraints of the theory simplify in terms of the new canonical variables and
are equivalent to the vanishing of the canonical momenta. Our work is based on
earlier seminal work by Kuchar in which he reconstructed curvature coordinates
and a mass function from spherically symmetric canonical data. The key feature
in our construction of a nonsingular canonical transformation to Kruskal
variables, is the scaling of the curvature coordinate variables by the mass
function rather than by the mass at left spatial infinity.Comment: 18 pages, no figure
5'-terminal structure of poliovirus polyribosomal RNA is pUp
Poliovirus RNA purified from virus-specific polyribosomes does not contain m7G in a 5'-5'-pyrophosphate linkage at its 5'-end. The only potential 5'-end found in ribonuclease digests of this RNA is pUp, which is present in a yield of 1 mole/mole of poliovirus RNA. We conclude that a 5'-terminal m7G is not required for translation of at least one RNA species in animal cells
Interoperability between Multimedia Collections for Content and Metadata-Based Searching
Artiste is a European project developing a cross-collection search system for art galleries and museums. It combines image content retrieval with text based retrieval and uses RDF mappings in order to integrate diverse databases. The test sites of the Louvre, Victoria and Albert Museum, Uffizi Gallery and National Gallery London provide their own database schema for existing metadata, avoiding the need for migration to a common schema. The system will accept a query based on one museum’s fields and convert them, through an RDF mapping into a form suitable for querying the other collections. The nature of some of the image processing algorithms means that the system can be slow for some computations, so the system is session-based to allow the user to return to the results later. The system has been built within a J2EE/EJB framework, using the Jboss Enterprise Application Server
Halflife of 56Ni in cosmic rays
A measurement of the 56Ni cosmic ray abundance has been discussed as a
possible tool to determine the acceleration time scale of relativistic
particles in cosmic rays. This conjecture will depend on the halflife of
totally ionized 56Ni which can only decay by higher-order forbidden
transitions. We have calculated this halflife within large-scale shell model
calculations and find t_{1/2} \approx 4 \times 10^4 years, only slightly larger
than the currently available experimental lower limit, but too short for 56Ni
to serve as a cosmic ray chronometer.Comment: 3 pages, 1 figur
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