695 research outputs found

    A thermodynamically self-consistent theory for the Blume-Capel model

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    We use a self-consistent Ornstein-Zernike approximation to study the Blume-Capel ferromagnet on three-dimensional lattices. The correlation functions and the thermodynamics are obtained from the solution of two coupled partial differential equations. The theory provides a comprehensive and accurate description of the phase diagram in all regions, including the wing boundaries in non-zero magnetic field. In particular, the coordinates of the tricritical point are in very good agreement with the best estimates from simulation or series expansion. Numerical and analytical analysis strongly suggest that the theory predicts a universal Ising-like critical behavior along the λ\lambda-line and the wing critical lines, and a tricritical behavior governed by mean-field exponents.Comment: 11 figures. to appear in Physical Review

    Influence of case definition on incidence and outcome of acute coronary syndromes

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    © 2016, BMJ Publishing Group. All rights reserved. Objective: Acute coronary syndromes (ACS) are common, but their incidence and outcome might depend greatly on how data are collected. We compared case ascertainment rates for ACS and myocardial infarction (MI) in a single institution using several different strategies. Methods: The Hull and East Yorkshire Hospitals serve a population of ∌560 000. Patients admitted with ACS to cardiology or general medical wards were identified prospectively by trained nurses during 2005. Patients with a death or discharge code of MI were also identified by the hospital information department and, independently, from Myocardial Infarction National Audit Project (MINAP) records. The hospital laboratory identified all patients with an elevated serum troponin-T (TnT) by contemporary criteria ( > 0.03 ÎŒg/L in 2005). Results: The prospective survey identified 1731 admissions (1439 patients) with ACS, including 764 admissions (704 patients) with MIs. The hospital information department reported only 552 admissions (544 patients) with MI and only 206 admissions (203 patients) were reported to the MINAP. Using all 3 strategies, 934 admissions (873 patients) for MI were identified, for which TnT was > 1 ÎŒg/L in 443, 0.04-1.0 ÎŒg/L in 435, =0.03 ÎŒg/L in 19 and not recorded in 37. A further 823 patients had TnT > 0.03 ÎŒg/L, but did not have ACS ascertained by any survey method. Of the 873 patients with MI, 146 (16.7%) died during admission and 218 (25.0%) by 1 year, but ranging from 9% for patients enrolled in the MINAP to 27% for those identified by the hospital information department. Conclusions: MINAP and hospital statistics grossly underestimated the incidence of MI managed by our hospital. The 1-year mortality was highly dependent on the method of ascertainment

    Outcomes After Percutaneous Coronary Intervention in Women: Are There Differences When Compared with Men?

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    Despite advances in the diagnosis and treatment of coronary artery disease, there remains evidence of a disparity in the outcomes for women when compared with men. This article provides a review of the evidence for this discrepancy and discusses some of the potential contributing factors

    Are they ‘worth their weight in gold’? Sport for older adults: benefits and barriers of their participation for sporting organisations

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    The ageing global population has led to an increased focus on health for older adults. However, older adults have not been a specific priority for some sporting organisations (SOs). Thus, there is an emerging opportunity for this age group to be considered within international sport policy. The aim of this study was to understand the benefits and barriers that SOs encounter when engaging older adults. Eight focus group interviews (n = 49) were held with representatives of Australian national sporting organisations (NSOs), and older adults who were either sport club or non-sport club members. The socioecological model domains, interpersonal, organisational and policy, were used as a framework for thematic analysis, and organisational capacity building concepts were utilised to explain the findings. Common perceived benefits included interpersonal benefits (intergenerational opportunities and role models) and organisational benefits (volunteering, financial contributions and maximised facility usage) for engaging older adults. Common perceived barriers included interpersonal barriers (competing priorities and perceived societal expectations), organisational barriers (lack of appropriate playing opportunities, lack of facility access and lack of club capacity) and policy barriers (strategic organisational focus on children and elite sport and risk management). Whilst participation in sport is not common for older adults, their involvement can be invaluable for sport clubs. It is not anticipated that any policy focus on older adults will significantly increase active participation for this age group. However, any increase in older adults’ sport participation either through actively playing, supporting family and friends and/or volunteering will contribute to the positive health of individuals, sport clubs and the community.Peer reviewedFinal Accepted Versio

    Density anomaly in a competing interactions lattice gas model

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    We study a very simple model of a short-range attraction and an outer shell repulsion as a test system for demixing phase transition and density anomaly. The phase-diagram is obtained by applying mean field analysis and Monte Carlo simulations to a two dimensional lattice gas with nearest-neighbors attraction and next-nearest-neighbors repulsion (the outer shell). Two liquid phases and density anomaly are found. The coexistence line between these two liquid phases meets a critical line between the fluid and the low density liquid at a tricritical point. The line of maximum density emerges in the vicinity of the tricritical point, close to the demixing transition

    Liquid-Liquid Phase Transition for an Attractive Isotropic Potential with Wide Repulsive Range

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    Recent experimental and theoretical results have shown the existence of a liquid-liquid phase transition in isotropic systems, such as biological solutions and colloids, whose interaction can be represented via an effective potential with a repulsive soft-core and an attractive part. We investigate how the phase diagram of a schematic general isotropic system, interacting via a soft-core squared attractive potential, changes by varying the parameters of the potential. It has been shown that this potential has a phase diagram with a liquid-liquid phase transition in addition to the standard gas-liquid phase transition and that, for a short-range soft-core, the phase diagram resulting from molecular dynamics simulations can be interpreted through a modified van der Waals equation. Here we consider the case of soft-core ranges comparable with or larger than the hard-core diameter. Because an analysis using molecular dynamics simulations of such systems or potentials is too time-demanding, we adopt an integral equation approach in the hypernetted-chain approximation. Thus we can estimate how the temperature and density of both critical points depend on the potential's parameters for large soft-core ranges. The present results confirm and extend our previous analysis, showing that this potential has two fluid-fluid critical points that are well separated in temperature and in density only if there is a balance between the attractive and repulsive part of the potential. We find that for large soft-core ranges our results satisfy a simple relation between the potential's parameters

    Critical behavior of a fluid in a disordered porous matrix: An Ornstein-Zernike approach

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    Using a liquid-state approach based on Ornstein-Zernike equations, we study the behavior of a fluid inside a porous disordered matrix near the liquid-gas critical point.The results obtained within various standard approximation schemes such as lowest-order Îł\gamma-ordering and the mean-spherical approximation suggest that the critical behavior is closely related to that of the random-field Ising model (RFIM).Comment: 10 pages, revtex, to appear in Physical Review Letter

    Emerging Indoor Photovoltaic Technologies for Sustainable Internet of Things

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    Funder: Priority Academic Program Development of Jiangsu Higher Education Institutions; Id: http://dx.doi.org/10.13039/501100012246Funder: 111 Project; Id: http://dx.doi.org/10.13039/501100013314Funder: Joint International Research Laboratory of Carbon‐Based Functional Materials and DevicesFunder: European Union; Id: http://dx.doi.org/10.13039/501100000780Abstract: The Internet of Things (IoT) provides everyday objects and environments with “intelligence” and data connectivity to improve quality of life and the efficiency of a wide range of human activities. However, the ongoing exponential growth of the IoT device ecosystem—up to tens of billions of units to date—poses a challenge regarding how to power such devices. This Progress Report discusses how energy harvesting can address this challenge. It then discusses how indoor photovoltaics (IPV) constitutes an attractive energy harvesting solution, given its deployability, reliability, and power density. For IPV to provide an eco‐friendly route to powering IoT devices, it is crucial that its underlying materials and fabrication processes are low‐toxicity and not harmful to the environment over the product life cycle. A range of IPV technologies—both incumbent and emerging—developed to date is discussed, with an emphasis on their environmental sustainability. Finally, IPV based on emerging lead‐free perovskite‐inspired absorbers are examined, highlighting their status and prospects for low‐cost, durable, and efficient energy harvesting that is not harmful to the end user and environment. By examining emerging avenues for eco‐friendly IPV, timely insight is provided into promising directions toward IPV that can sustainably power the IoT revolution
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