1,826 research outputs found
Superfluidity and dimerization in a multilayered system of fermionic polar molecules
We consider a layered system of fermionic molecules with permanent dipole
moments aligned by an external field. The dipole interactions between fermions
in adjacent layers are attractive and induce inter-layer pairing. Due to
competition for pairing among adjacent layers, the mean-field ground state of
the layered system is a dimerized superfluid, with pairing only between
every-other layer. We construct an effective Ising-XY lattice model that
describes the interplay between dimerization and superfluid phase fluctuations.
In addition to the dimerized superfluid ground state, and high temperature
normal state, at intermediate temperature, we find an unusual dimerized
"pseudogap" state with only short-range phase coherence. We propose light
scattering experiments to detect dimerization.Comment: 4 pages main text + 3 pages supplemental Appendices, 4 figure
A Policy Impact Evaluation Model For Scotland: Decoupling Single Farm Payments
The purpose of this paper is to assess the impacts of decoupling single farm payments in Scotland. It focuses on aggregate impacts on the agricultural products in domestic and external markets and the spill-over effect of this on the non-agricultural sector as well as an aggregate impact on the Scottish GDP. In order to capture system-wide impacts of the policy reform, a CGE model was formulated and implemented using a social accounting matrix constructed for Scotland. The simulation results suggest that the Scottish agricultural sector may encounter declines in output and factor us as a result of the policy reform. However, this critically depends on two factors: (a) the price effect of the policy reform on Scottish agricultural products relative to the EU average as well as the conditions of changes in world agricultural market prices; and (b) the extent to which customers would be sensitive to price effects of the policy reform. As far as the spill-over effect to the non-agricultural sector is concerned, decoupling of direct payments seems to have a positive spill-over effect. Similarly, the aggregate GDP effect is positive under all simulation scenarios. Critically, the simulation experiments indicate that policy shock may have a symmetrical outcome across the two sectors, with contractions in agriculture being accompanied by expansions in the non-agricultural sector, mainly because of factor market interactions between the two sectors.
Imaging the Gamma-Ray Sky with SPI aboard INTEGRAL
The spectrometer SPI on INTEGRAL allows for the first time simultaneous
imaging of diffuse and point-like emission in the hard X-ray and soft gamma-ray
regime. To fully exploit the capabilities of the instrument, we implemented the
MREM image deconvolution algorithm, initially developed for COMPTEL data
analysis, to SPI data analysis. We present the performances of the algorithm by
means of simulations and apply it to data accumulated during the first 2
mission years of INTEGRAL. Skymaps are presented for the 1809 keV gamma-ray
line, attributed to the radioactive decay of 26Al, and for continuum energy
bands, covering the range 20 keV - 3 MeV. The 1809 keV map indicates that
emission is clearly detected by SPI from the inner Galactic radian and from the
Cygnus region. The continuum maps reveal the transition between a point-source
dominated hard X-ray sky to a diffuse emission dominated soft gamma-ray sky.
From the skymaps, we extract a Galactic ridge emission spectrum that matches
well SPI results obtained by model fitting. By comparing our spectrum with the
cumulative flux measured by IBIS from point sources, we find indications for
the existence of an unresolved or diffuse emission component above ~100 keV.Comment: 12 pages, 7 figure
VARIATION IN LANDING DURING GYMNASTICS SKILLS
The aim of this study was to examine joint motion during landing from a variety of gymnastics skills. Twelve gymnasts performed a range of gymnastics skills with a landing
component. Joint angles of the ankle, knee and hip were examined during landing from five different skills. There were significant differences between skills at all joints for peak
flexion and extension (ankle, knee and hip:
METHOD FOR THE DETECTION OF FATIGUE DURING GYMNASTICS TRAINING
The purpose of this study was to determine if acceleration measured at the pelvis was a suitable indicator of fatigue in gymnasts. Fourteen gymnasts performed vertical jumps and drop landings pre and post a fatiguing jumping activity. Peak acceleration during landing for jumps and drops increased significantly after fatiguing activity. Acceleration is a tool that can be collected with limited disruption to gymnastics training and an increase in peak acceleration during landing of simple jumps appears to be a useful tool for determining whether gymnasts are fatigued
Intermittent Attractive Interactions Lead to Microphase Separation in Non-motile Active Matter
Non-motile active matter exhibits a wide range of non-equilibrium collective
phenomena yet examples are crucially lacking in the literature. We present a
microscopic model inspired by the bacteria {\it Neisseria Meningitidis} in
which diffusive agents feel intermittent attractive forces. Through a formal
coarse-graining procedure, we show that this truly scalar model of active
matter exhibits the time-reversal-symmetry breaking terms defining the {\it
Active Model B+} class. In particular, we confirm the presence of microphase
separation by solving the kinetic equations numerically. We show that the
switching rate controlling the interactions provides a regulation mechanism
tuning the typical cluster size, e.g. in populations of bacteria interacting
via type IV pili.Comment: 7 pages (4 figures) of main text plus 12 pages (2 figures) of
supplementary informatio
METHOD FOR ANALYSING THE RISK OF OVERUSE INJURY IN GYMNASTICS
The purpose of this study was to propose and assess a method for the evaluation of all loads experienced during gymnastics training. The method is based on the measurement of acceleration on the gymnast. Twelve gymnasts performed a range of gymnastics skills with an impact component. Ground reaction forces and acceleration at the pelvis were measured. There were significant correlations between peak GRF and peak acceleration during landing from gymnastics skills for individual participants. This testing showed the potential for this method to be applied in a study of injury risk factors outside the laboratory environment. At present, this relationship means that acceleration can be used as an estimation of force, after calibrating acceleration to ground reaction force for the individual
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Gas Diffusion Barriers Using Atomic Layer Deposition: A New Calcium Test and Polymer Substrate Effects
The increasing demand on available energy resources has led to a desire for more energy efficient devices. The wide use of displays in consumer electronics, such as televisions, cell phones, cameras and computers makes them an ideal target for improvement. Organic light-emitting diodes (OLEDs) are a good candidate to replace traditional Si based devices. However, the low work function metals typically used as electrodes in OLEDs are very reactive with water and oxygen. Ultralow permeability gas diffusion barriers with water vapor transmission rates (WVTRs) as low as \u3c10-6 g/(m2 *day) are required on the polymers used to fabricate organic electronic and thin film photovoltaic devices.
Atomic Layer Deposition (ALD) uses self-limiting surface reactions to deposit thin conformal films. ALD is capable of depositing thin, conformal, high quality barriers. WVTR values as low as ≤ 5 x 10-5 g/( m2 *day) have been measured for Al2O3 ALD films at 38°C/85% RH using the Ca test with optical transmission probing. The Ca test is a technique with very high sensitivity to measure ultralow WVTRs. This test relies on measuring the oxidation of a Ca metal film by monitoring the change in its optical or electrical properties. However, glass lid control experiments have indicated that the WVTRs measured by the Ca test are limited by H2O permeability through the epoxy seals. Varying results have been reported in the literature using the electrical conductance of Ca to measure permeation.
In this work, two approaches were applied to overcome the epoxy edge seal limitations. The first approach was to deposit Al2O3 ALD barriers directly on Ca metal. While the Al2O3 ALD barriers were successfully deposited, the measurement of an accurate WVTR was limited by barrier pinholes. The presence of pinholes in the Al2O3 ALD barrier on Ca results in the localized oxidation of the Ca sensor. Heterogeneous degradation of the Ca causes inaccuracies in the conductance of the film. As oxidation regions merge, large percolation paths are severed without complete Ca oxidation. To solve this problem, a new apparatus was developed that measures the electrical conductance of Ca films. This new apparatus does not rely on epoxy seals and separates the Ca metal from the barrier. Unfortunately, the electrical conductance of the Ca film versus Ca oxidation was found to be extremely nonlinear. This nonlinearity severely complicates the usual analysis to obtain WVTR values from the Ca test.
The new apparatus was useful for the examination of PEN polymer substrates using the total lifetime of the Ca sensor. Polymer effects on the measurement of gas permeability for polymer/barrier systems have largely been ignored. Experiments were performed to determine the effect of the PEN polymer substrates on the WVTR measurement. The H2O permeation activation energy in the PEN polymer, the effect of water saturation of the PEN polymer and the dependence of the lifetime of the Ca sensor on the H2O flux on the PEN substrate were of particular interest. The experiments obtained H2O permeation activation energies in the PEN polymer of 12.4 kJ/mol. The Ca sensor lifetime was found to be linear with H2O flux. No difference in Ca sensor lifetime was observed between dry or H2O-saturated PEN polymer substrates
Totality and autonomy: George Eliot and the power of narrative
This study aims to explore George Eliot's early fiction in terms of her response to the two competing philosophical traditions of Spinoza and Kant. The dispute between these two traditions begins from differing claims regarding the possibility of metaphysical knowledge, and this of course will have important consequences for both ethics and aesthetics. I argue that Eliot, through her fiction, contributed powerfully to this debate, and my central concern will be her choice of the novel genre as a medium for these ethical and philosophical interventions. The first part of this study sets out the terms of this historical debate, and considers Eliot's distinctive philosophical, ethical and literary programme, which I describe as a 'religion of immanence'. I offer readings of Scenes of Clerical Life and Adam Bede in relation to various philosophical issues such as Spinoza's three kinds of knowledge, Kantian ethics and aesthetics, hermeneutics and biblical criticism, and the literary theory of the early Romantics. The second part of this study draws together these various historical strands, and in a sustained reading of The Mill on the Floss attempts to place Eliot within a post-Romantic paradigm, which is seen as a way of unifying the two traditions with which Eliot engages. I show how Eliot's fiction interacts with the literary theory of the Jena Romantics, and most importantly their conception of music as a paradigm for a non-representational approach to language and literature. I also discuss Eliot's use of the Bildungsroman model, which throws up surprising connections between hermeneutics and that other intense search for origins, Darwinism. I argue that George Eliot's negotiation of these philosophical issues is played out through narrative, which is at the heart of a distinctive ethical and literary project that draws upon the rich resources of the Aristotelian tradition
Multi-modal characterisation of early-stage, subclinical cardiac deterioration in patients with type 2 diabetes
Background: Type 2 diabetes mellitus (T2DM) is a major risk factor for heart failure with preserved ejection fraction and cardiac arrhythmias. Precursors of these complications, such as diabetic cardiomyopathy, remain incompletely understood and underdiagnosed. Detection of early signs of cardiac deterioration in T2DM patients is critical for prevention. Our goal is to quantify T2DM-driven abnormalities in ECG and cardiac imaging biomarkers leading to cardiovascular disease. Methods: We quantified ECG and cardiac magnetic resonance imaging biomarkers in two matched cohorts of 1781 UK Biobank participants, with and without T2DM, and no diagnosed cardiovascular disease at the time of assessment. We performed a pair-matched cross-sectional study to compare cardiac biomarkers in both cohorts, and examined the association between T2DM and these biomarkers. We built multivariate multiple linear regression models sequentially adjusted for socio-demographic, lifestyle, and clinical covariates. Results: Participants with T2DM had a higher resting heart rate (66 vs. 61 beats per minute, p < 0.001), longer QTc interval (424 vs. 420ms, p < 0.001), reduced T wave amplitude (0.33 vs. 0.37mV, p < 0.001), lower stroke volume (72 vs. 78ml, p < 0.001) and thicker left ventricular wall (6.1 vs. 5.9mm, p < 0.001) despite a decreased Sokolow-Lyon index (19.1 vs. 20.2mm, p < 0.001). T2DM was independently associated with higher heart rate (beta = 3.11, 95% CI = [2.11,4.10], p < 0.001), lower stroke volume (beta = −4.11, 95% CI = [−6.03, −2.19], p < 0.001) and higher left ventricular wall thickness (beta = 0.133, 95% CI = [0.081,0.186], p < 0.001). Trends were consistent in subgroups of different sex, age and body mass index. Fewer significant differences were observed in participants of non-white ethnic background. QRS duration and Sokolow-Lyon index showed a positive association with the development of cardiovascular disease in cohorts with and without T2DM, respectively. A higher left ventricular mass and wall thickness were associated with cardiovascular outcomes in both groups. Conclusion: T2DM prior to cardiovascular disease was linked with a higher heart rate, QTc prolongation, T wave amplitude reduction, as well as lower stroke volume and increased left ventricular wall thickness. Increased QRS duration and left ventricular wall thickness and mass were most strongly associated with future cardiovascular disease. Although subclinical, these changes may indicate the presence of autonomic dysfunction and diabetic cardiomyopathy
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