Transport coefficients and nonextensive statistics

We discuss the basic transport phenomena in gases and plasmas obeying the $q$-nonextensive velocity distribution (power-law). Analytical expressions for the thermal conductivity ($K_q$) and viscosity ($\eta_q$) are derived by solving the Boltzmann equation in the relaxation-time approximation. The available experimental results to the ratio {$K_q$}/$\eta_q$ constrains the $q$-parameter on the interval $0.74 \leq q \leq 1$. In the extensive limiting case, the standard transport coefficients based on the local Gaussian distribution are recovered, and due to a surprising cancellation, the electric conductivity of a neutral plasma is not modified.Comment: 14 pages, 3 figures, REVTEX, submitted to PR

Evidence for a Binary Companion to the Central Compact Object 1E 1207.4-5209

Unique among neutron stars, 1E 1207.4-5209 is an X-ray pulsar with a spin period of 424 ms that contains at least two strong absorption features in its energy spectrum. This neutron star has been identified as a member of the radio-quiet compact central objects in supernova remnants. It has been found that 1E 1207.4-5209 is not spinning down monotonically suggesting that this neutron star undergoes strong, frequent glitches, contains a fall-back disk, or possess a binary companion. Here, we report on a sequence of seven XMM-Newton observations of 1E 1207.4-5209 performed during a 40 day window in June/July 2005. Due to unanticipated variance in the phase measurements beyond the statistical uncertainties, we could not identify a unique phase-coherent timing solution. The three most probable timing solutions give frequency time derivatives of +0.9, -2.6, and +1.6 X 10^(-12) Hz/s (listed in descending order of significance). We conclude that the local frequency derivative during our XMM-Newton observing campaign differs from the long-term spin-down rate by more than an order of magnitude, effectively ruling out glitch models for 1E 1207.4-5209. If the long-term spin frequency variations are caused by timing noise, the strength of the timing noise in 1E 1207.4-5209 is much stronger than in other pulsars with similar period derivatives. Therefore, it is highly unlikely that the spin variations are caused by the same physical process that causes timing noise in other isolated pulsars. The most plausible scenario for the observed spin irregularities is the presence of a binary companion to 1E 1207.4-5209. We identified a family of orbital solutions that are consistent with our phase-connected timing solution, archival frequency measurements, and constraints on the companions mass imposed by deep IR and optical observations.Comment: 8 pages, 4 figures. To be published in the proceedings of "Isolated Neutron Stars: from the Interior to the Surface" (April 24-28, 2006) - eds. D. Page, R. Turolla & S. Zan

A geological model of the chalk of East Kent

This report describes the geological modelling of the Chalk in the North Downs of East Kent, within the catchment of River Great Stour and eastwards to the coast, including the Isle of Thanet. This work was funded by the Environment Agency to support investigations of the local hydrogeology and thereby to enhance catchment management. The whole area is underlain by the Upper Cretaceous Chalk Group, with the Palaeogene succession of the Thanet Sand Formation, the Lambeth Group and the Thames Group overlying it in the northern and central eastern parts. The project included a desk study revision of the Chalk of the North Downs, using the new Chalk lithostratigraphy. The revisions to the geology are shown on the 1:50 000 scale geological map which accompanies this report. Together with evidence from boreholes and from seismic surveys, the new outcrop patterns have been incorporated into a geological model, using both computer software (EarthVision) and manual methods. The introduction describes the background to the project. The second chapter describes the sources for the data used in the model: published and unpublished geological maps, borehole records (both lithological and geophysical), seismic surveys, biostratigraphic records, digital topographic information, and the published literature. Each Chalk formation present in the area is then briefly described in the third chapter, noting its relationship to the older lithostratigraphic divisions, and to biostratigraphic zones. The local Chalk succession extends from the base of the Chalk Group to the Newhaven Chalk Formation, here represented by the Margate Chalk Member. Evidence for the thickness of each formation is reviewed. The early Palaeogene formations (the Thanet Sand, Upnor, Harwich and London Clay formations) are also briefly described (Chapter 4) and the local superficial deposits mentioned, with references to detailed descriptions (Chapter 5). Apart from minor adjustments to the outcrop of the basal Palaeogene surface, no revision of these formations was done for this study

Progressive damage on high resolution computed tomography despite stable lung function in cystic fibrosis

For effective clinical management of cystic fibrosis (CF) lung disease it is important to closely monitor the start and progression of lung damage. The aim of this study was to investigate the ability of high-resolution computed tomography (HRCT) scoring systems and pulmonary function tests (PFT) to detect changes in lung disease. CF children (n=48) had two H

From bound states to resonances: analytic continuation of the wave function

Single-particle resonance parameters and wave functions in spherical and deformed nuclei are determined through analytic continuation in the potential strength. In this method, the analyticity of the eigenvalues and eigenfunctions of the Schroedinger equation with respect to the coupling strength is exploited to analytically continue the bound-state solutions into the positive-energy region by means of Pade' approximants of the second kind. The method is here applied to single-particle wave functions of the $^{154}Sm$ and $^{131}Eu$ nuclei. A comparison of the results with the direct solution of the Schroedinger equation shows that the method can be confidently applied also in coupled-channel situations requiring high numerical accuracy.Comment: 13 pages, 3 figure

Further Comparison between ATNoSFERES and XCSM

International audienceIn this paper we present ATNoSFERES, a new framework based on an indirect encoding Genetic Algorithm which builds finite-state automata controllers able to deal with perceptual aliazing. In the context of our ongoing line of research, we compare it with XCSM, a memory-based extension of the most studied Learning Classifier System, XCS, through two benchmark experiments. We focus in particular on internal state generalization, and add special purpose features to ATNoSFERES to fulfill that comparison. We then discuss the role played by internal state generalization in the experiments studied

National geological screening : East Anglia region

This report is the published product of one of a series of studies covering England, Wales and Northern Ireland commissioned by Radioactive Waste Management (RWM) Ltd. The report provides geological information about the East Anglia region to underpin the process of national geological screening set out in the UK’s government White Paper Implementing geological disposal: a framework for the long-term management of higher activity radioactive waste (DECC, 2014). The report describes geological features relevant to the safety requirements of a geological disposal facility (GDF) for radioactive waste emplaced onshore and up to 20 km offshore at depths between 200 and 1000 m from surface. It is written for a technical audience but is intended to inform RWM in its discussions with communities interested in finding out about the potential for their area to host a GDF

Theory of nuclear induced spectral diffusion: Spin decoherence of phosphorus donors in Si and GaAs quantum dots

We propose a model for spectral diffusion of localized spins in semiconductors due to the dipolar fluctuations of lattice nuclear spins. Each nuclear spin flip-flop is assumed to be independent, the rate for this process being calculated by a method of moments. Our calculated spin decoherence time $T_{M}=0.64$ ms for donor electron spins in Si:P is a factor of two longer than spin echo decay measurements. For $^{31}$P nuclear spins we show that spectral diffusion is well into the motional narrowing regime. The calculation for GaAs quantum dots gives $T_{M}=10-50$ $\mu$s depending on the quantum dot size. Our theory indicates that nuclear induced spectral diffusion should not be a serious problem in developing spin-based semiconductor quantum computer architectures.Comment: 15 pages, 9 figures. Accepted for publication in Phys. Rev.

Boundary conditions of workplace coaching outcomes

Purpose In order to address the need for greater understanding about the occupational and practice determinants of effective workplace coaching, this study examines the associations of two coaching practice factors (coaching format and external versus internal coaching provision), and coachees’ job complexity with perceived outcomes from coaching. Design/methodology/approach A survey of 161 individuals who had received workplace coaching was conducted. Participants provided data on two outcome criteria (self-reported work well-being and personal effectiveness at work). Findings Analysis indicated that external coaches and blended format coaching were most strongly associated with work well-being outcomes. Our examination of interaction effects showed that coaching provided by external coaches was more strongly associated with outcomes for individuals working in the most complex job roles. Originality/value The original contribution of our findings are in terms of the implications for coaches, managers and HR practitioners by showing how coaching can be implemented differentially and most effectively based on desired outcome criteria and features of coachees’ job situations

Goal-oriented cognitive rehabilitation for early-stage Alzheimer's and related dementias: the GREAT RCT

This is the author accepted manuscript. The final version is available from NIHR Journals Library via the DOI in this record.The published version is available in ORE at http://hdl.handle.net/10871/36867This study was funded by the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme; PI Professor L Clare; HTA reference 11/15/04