471 research outputs found
‘Prisoners abroad’ resettlement service: Housing security and lessons for probation
This paper reports from a small-scale qualitative study involving people imprisoned overseas and supported by the resettlement service ‘Prisoners’ Abroad’ following deportation to the UK. A key focus of Prisoners’ Abroad resettlement work is assisting ‘returnees’ into secure accommodation and to retain housing tenancies over the longer-term in efforts to prevent homelessness. The centrality of housing from the perspectives of both the service users and Prisoners Abroad staff provide important insights and lessons for wider probation practice. Without a housing base, people lack the certainty and stability needed to address practical and emotional issues typically experienced after prison. Moreover, to establish the requisites for everyday functioning so that moving forward can be achieved
Coherent phenomena in mesoscopic systems
A mesoscopic system of cylindrical geometry made of a metal or a
semiconductor is shown to exhibit features of a quantum coherent state. It is
shown that magnetostatic interaction can play an important role in mesoscopic
systems leading to an ordered ground state. The temperature below the
system exhibits long-range order is determined. The self-consistent mean field
approximation of the magnetostatic interaction is performed giving the
effective Hamiltonian from which the self-sustaining currents can be obtained.
The relation of quantum coherent state in mesoscopic cylinders to other
coherent systems like superconductors is discussed.Comment: REVTeX, 4 figures, in print in Supercond. Sci. Techno
Conductance of a tunnel point-contact of noble metals in the presence of a single defect
In paper [1] (Avotina et al. Phys. Rev. B,74, 085411 (2006)) the effect of
Fermi surface anisotropy to the conductance of a tunnel point contact, in the
vicinity of which a single point-like defect is situated, has been investigated
theoretically. The oscillatory dependence of the conductance on the distance
between the contact and the defect has been found for a general Fermi surface
geometry. In this paper we apply the method developed in [1] to the calculation
of the conductance of noble metal contacts. An original algorithm, which
enables the computation of the conductance for any parametrically given Fermi
surface, is proposed. On this basis a pattern of the conductance oscillations,
which can be observed by the method of scanning tunneling microscopy, is
obtained for different orientations of the surface for the noble metals.Comment: 8 pages, 5 figure
Theory of oscillations in the STM conductance resulting from subsurface defects (Review Article)
In this review we present recent theoretical results concerning
investigations of single subsurface defects by means of a scanning tunneling
microscope (STM). These investigations are based on the effect of quantum
interference between the electron partial waves that are directly transmitted
through the contact and the partial waves scattered by the defect. In
particular, we have shown the possibility imaging the defect position below a
metal surface by means of STM. Different types of subsurface defects have been
discussed: point-like magnetic and non-magnetic defects, magnetic clusters in a
nonmagnetic host metal, and non-magnetic defects in a s-wave superconductor.
The effect of Fermi surface anisotropy has been analyzed. Also, results of
investigations of the effect of a strong magnetic field to the STM conductance
of a tunnel point contact in the presence of a single defect has been
presented.Comment: 31 pages, 10 figuers Submitted to Low. Temp. Phy
Little groups of irreps of O(3), SO(3), and the infinite axial subgroups
Little groups are enumerated for the irreps and their components in any basis
of O(3) and SO(3) up to rank 9, and for all irreps of C, C, C, D and D. The results are obtained
by a new chain criterion, which distinguishes massive (rotationally
inequivalent) irrep basis functions and allows for multiple branching paths,
and are verified by inspection. These results are relevant to the determination
of the symmetry of a material from its linear and nonlinear optical properties
and to the choices of order parameters for symmetry breaking in liquid
crystals.Comment: 28 pages and 3 figure
Possibility of long-range order in clean mesoscopic cylinders
A microscopic Hamiltonian of the magnetostatic interaction is discussed. This
long-range interaction can play an important role in mesoscopic systems leading
to an ordered ground state.
The self-consistent mean field approximation of the magnetostatic interaction
is performed to give an effective Hamiltonian from which the spontaneous,
self-sustaining currents can be obtained.
To go beyond the mean field approximation the mean square fluctuation of the
total momentum is calculated and its influence on self-sustaining currents in
mesoscopic cylinders with quasi-1D and quasi-2D conduction is considered. Then,
by the use of the microscopic Hamiltonian of the magnetostatic interaction for
a set of stacked rings, the problem of long-range order is discussed. The
temperature below which the system is in an ordered state is
determined.Comment: 14 pages, REVTeX, 5 figures, in print in Phys. Rev.
Intraindividual variability and falls in older adults
Objective: We investigated whether a simple measure of reaction time intraindividual variability (IIV) was associated with falls in older adults. Falls and fall-related injuries represent a major cost to health care systems, it is therefore critically important to find measures that can readily identify older adults at greater risk of falling. Method: Cognitive and motor function were investigated in 108 adults aged 53 to 93 years (M= 73.49) recruited across the local community and hospital outpatient department. Forty-two participants had experienced either an injurious fall, or multiple falls, in the previous two years. Results: Logistic regression suggested that fallers could be distinguished from non-fallers by greater medication use, IIV, postural sway, weaker grip strength and slower gait speed. Structural equation models revealed that IIV as predictive of falls via the mediating variable of motor function (e.g., gait). IIV also predicted higher-order cognition (executive function) but higher-order cognitive function did not uniquely predict falls or account for the associations between IIV and falls. Conclusions: These findings indicate that IIV measures capture important aspects of cognitive and motor decline and may have considerable potential in identifying older adults at risk of falling in healthcare and community settings
Spatial Correlation of Conduction Electrons in Metal with Complicated Geometry Of The Fermi Surface
The "density-density" correlation function of conduction electrons in metal
is investigated. It is shown, that the asymptotic behaviour of the CF depends
on the shape and the local geometry of the Fermi surface. In particular, the
exponent of power law which describes the damping of Friedel oscillations at
large r (-4 for an isotropic Fermi gas) is determined by local geometry of the
FS. The applications of the obtained results to calculations of the CF in a
metal near the electron topological transition and of the RKKY exchange
integral are considered as well.Comment: 12 pages, LaTeX, 5 figures upon request (to appear in J.Phys.:CM,
1993
Fermi Surface of the Electron-doped Cuprate Superconductor Nd_{2-x}Ce_xCuO_{4} Probed by High-Field Magnetotransport
We report on the study of the Fermi surface of the electron-doped cuprate
superconductor NdCeCuO by measuring the interlayer
magnetoresistance as a function of the strength and orientation of the applied
magnetic field. We performed experiments in both steady and pulsed magnetic
fields on high-quality single crystals with Ce concentrations of to
0.17. In the overdoped regime of we found both semiclassical
angle-dependent magnetoresistance oscillations (AMRO) and Shubnikov-de Haas
(SdH) oscillations. The combined AMRO and SdH data clearly show that the
appearance of fast SdH oscillations in strongly overdoped samples is caused by
magnetic breakdown. This observation provides clear evidence for a
reconstructed multiply-connected Fermi surface up to the very end of the
overdoped regime at . The strength of the superlattice potential
responsible for the reconstructed Fermi surface is found to decrease with
increasing doping level and likely vanishes at the same carrier concentration
as superconductivity, suggesting a close relation between translational
symmetry breaking and superconducting pairing. A detailed analysis of the
high-resolution SdH data allowed us to determine the effective cyclotron mass
and Dingle temperature, as well as to estimate the magnetic breakdown field in
the overdoped regime.Comment: 23 pages, 8 figure
Exploring attitudes to edgy urban destinations: the case of Deptford, London
The role of tourists and tourism in urban development is not fully understood. Research has focused on tourism districts within city centres, but less is known about tourism in peripheral, less affluent urban districts. These areas can appeal to visitors as edgy alternatives to mainstream destinations. This study establishes who is interested in visiting and why, and it explores the underlying rationale for negative attitudes. The aims are addressed by an in-depth analysis of Deptford in South East London. This area is a relatively deprived part of a world city, albeit one that has long been earmarked as London's next cool district. The study uses a mix of different sources to analyse the case. Responses to a New York Times article on Deptford are analysed and the attitudes of actual visitors and key stakeholders are explored. The discussion includes an examination of different interpretations and attitudes towards the notion of edginess. Edginess is deemed attractive by certain audiences; something linked to a reverence for working-class life in the arts. The study concludes that, whilst edginess is a noted characteristic, what people appreciate about Deptford is its ‘distinctive ordinariness’ – its contrast with more polished and contrived urban districts
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