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 $p(2\times 3)$ 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