63 research outputs found

    The challenges of change:Exploring the dynamics of police reform in Scotland

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    Despite a long tradition of pessimism regarding the scope for meaningful change in police practices, recent structural reforms to police organizations in several European countries suggest that significant change in policing is possible. Drawing on recent research into the establishment and consequences of a national police force in Scotland, this article uses instrumental, cultural and myth perspectives taken from organization theory to examine how change happened and with what effects. It highlights how police reform involves a complex interplay between the strategic aims of government, the cultural norms of police organizations and the importance of alignment with wider views about the nature of the public sector. The article concludes by identifying a set of wider lessons from the experience of organizational change in policing

    Single 3dd transition metal atoms on multi-layer graphene systems: electronic configurations, bonding mechanisms and role of the substrate

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    The electronic configurations of Fe, Co, Ni, and Cu adatoms on graphene and graphite have been studied by x-ray magnetic circular dichroism and charge transfer multiplet theory. A delicate interplay between long-range interactions and local chemical bonding is found to influence the adatom equilibrium distance and magnetic moment. The results for Fe and Co are consistent with purely physisorbed species having, however, different 3dd-shell occupancies on graphene and graphite (dn+1d^{n+1} and dnd^n, respectively). On the other hand, for the late 3dd metals Ni and Cu a trend towards chemisorption is found, which strongly quenches the magnetic moment on both substrates.Comment: 7 pages, 4 figure

    Electronic structure of β\beta-SiAlON: effect of varying Al/O concentration at finite temperatures relevant for thermal quenchin

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    β\beta-Si6−z_{6-z}Alz_{z}Oz_{z}N8−z_{8-z} is a prominent example of systems suitable as hosts for creating materials for light-emitting diodes. In this work, the electronic structure of a series of ordered and disordered β\beta-Si6−z_{6-z}Alz_{z}Oz_{z}N8−z_{8-z} systems is investigated by means of ab initio calculations, using the FLAPW and the Green function KKR methods. Finite temperature effects are included within the alloy analogy model. We found that the trends with the Al/O doping are similar for ordered and disordered structures. The electronic band gap decreases with increasing zz by about 1 eV when going from zz=0 to zz=2. The optical gap decreases analogously as the electronic band gap. The changes in the density of states (DOS) at Si and N atoms introduced by doping β\beta-Si3_{3}N4_{4} with Al and O are comparable to the DOS at Al and O atoms themselves. The bottom of the conduction band in β\beta-Si6−z_{6-z}Alz_{z}Oz_{z}N8−z_{8-z} is formed by extended states residing on all atomic types. Increasing the temperature leads to a shift of the bottom of the conduction band to lower energies. The amount of this shift increases with increasing doping zz.Comment: 11 pages, 11 figures, 1 tabl

    Finite-temperature magnetism of Fex_xPd1−x_{1-x} and Cox_xPt1−x_{1-x} alloys

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    The finite-temperature magnetic properties of Fex_xPd1−x_{1-x} and Cox_xPt1−x_{1-x} alloys have been investigated. It is shown that the temperature-dependent magnetic behaviour of alloys, composed of originally magnetic and non-magnetic elements, cannot be described properly unless the coupling between magnetic moments at magnetic atoms (Fe,Co) mediated through the interactions with induced magnetic moments of non-magnetic atoms (Pd,Pt) is included. A scheme for the calculation of the Curie temperature (TCT_C) for this type of systems is presented which is based on the extended Heisenberg Hamiltonian with the appropriate exchange parameters JijJ_{ij} obtained from {\em ab-initio} electronic structure calculations. Within the present study the KKR Green's function method has been used to calculate the JijJ_{ij} parameters. A comparison of the obtained Curie temperatures for Fex_xPd1−x_{1-x} and Cox_xPt1−x_{1-x} alloys with experimental data shows rather good agreement.Comment: 10 pages, 12 figure
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