47,403 research outputs found
Density-functional study of oxygen adsorption on Mo(112)
Atomic oxygen adsorption on the Mo(112) surface has been investigated by
means of first-principles total energy calculations. Among the variety of
possible adsorption sites it was found that the bridge sites between two Mo
atoms of the topmost row are favored for O adsorption at low and medium
coverages. At about one monolayer coverage oxygen atoms prefer to adsorb in a
quasi-threefold hollow sites coordinated by two first-layer Mo atoms and one
second layer atom. The stability of a structural model for an oxygen-induced
reconstruction of the missing-row type is examined.Comment: 6 pages, 6 postscript figures, RevTe
Multiple zero modes of the Dirac operator in three dimensions
One of the key properties of Dirac operators is the possibility of a
degeneracy of zero modes. For the Abelian Dirac operator in three dimensions
the construction of multiple zero modes has been sucessfully carried out only
very recently. Here we generalise these results by discussing a much wider
class of Dirac operators together with their zero modes. Further we show that
those Dirac operators that do admit zero modes may be related to Hopf maps,
where the Hopf index is related to the number of zero modes in a simple way.Comment: Latex file, 20 pages, no figure
The 10% tax rate: where next?
In Budget 2007, the Government announced the abolition of the 10% starting rate of income tax alongside a wider set of reforms to personal taxes and tax credits to take effect during the period April 2008 to April 2010. Further changes to tax credits and state benefits were announced in PBR 2007 and Budget 2008, some to take effect in 2008-09, some in 2009-10 and others in 2010-11.
During April 2008, the Government said that it was looking at ways of compensating the net losers from these changes (in practice, those for whom the losses from the abolition of the 10% band exceeded the gains from the other measures). On 13 May it announced a £600 rise in the income tax personal allowance for 2008-09, with a corresponding cut in the higher-rate threshold.
In the light of these changes, this note looks at:
* To what extent the rise in the personal allowance, and other measures in Budget 2007, PBR 2007 and Budget 2008, compensate those who lost out from the abolition of the 10% rate of income tax;
* To what extent the Government's pre-announced changes to personal taxes, tax credits and benefits for 2010-11 provide compensation for these losers over the medium term;
* What options the Government has for 2009-10 and beyond
Blind image separation based on exponentiated transmuted Weibull distribution
In recent years the processing of blind image separation has been
investigated. As a result, a number of feature extraction algorithms for direct
application of such image structures have been developed. For example,
separation of mixed fingerprints found in any crime scene, in which a mixture
of two or more fingerprints may be obtained, for identification, we have to
separate them. In this paper, we have proposed a new technique for separating a
multiple mixed images based on exponentiated transmuted Weibull distribution.
To adaptively estimate the parameters of such score functions, an efficient
method based on maximum likelihood and genetic algorithm will be used. We also
calculate the accuracy of this proposed distribution and compare the
algorithmic performance using the efficient approach with other previous
generalized distributions. We find from the numerical results that the proposed
distribution has flexibility and an efficient resultComment: 14 pages, 12 figures, 4 tables. International Journal of Computer
Science and Information Security (IJCSIS),Vol. 14, No. 3, March 2016 (pp.
423-433
BPS Skyrme neutron stars in generalized gravity
We study the coupling of nuclear matter described by the BPS Skyrme model to
generalized gravity. Concretely, we consider the Starobinsky model which
provides the leading-order correction to the Einstein-Hilbert action. Static
solutions describing neutron stars are found both for the full field theory and
for the mean-field approximation. We always consider the full Starobinsky model
in the nonperturbative approach, using appropriately generalized shooting
methods for the numerical neutron star calculations. Many of our results are
similar to previous investigations of neutron stars for the Starobinsky model
using other models of nuclear matter, but there are some surprizing
discrepancies. The "Newtonian mass" relevant for the surface redshift, e.g.,
results larger than the ADM mass in our model, in contrast to other
investigations. This difference is related to the particularly high stiffness
of nuclear matter described by the BPS Skyrme model and offers an interesting
possibility to distinguish different models of nuclear matter within
generalized gravity.Comment: LaTex, 28 pages, 13 figures; v2: minor change
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