851 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

    Australian team sports athletes prefer dietitians, the internet and nutritionists for sports nutrition information

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    Aim To evaluate the information sources that are used and preferred by Australian athletes and to assess if preferences influence nutrition knowledge (NK). Methods Elite and non-elite Australian team sport athletes, playing Australian football (AF), cricket, lawn bowls, soccer or hockey, were recruited via the sporting organisations' qualified sports dietitians or club presidents. Athletes completed one of two online, validated sports NK questionnaires. Frequency analysis on previous sources of advice, preferred sources of information and preferred type of support were assessed. Differences in NK scores (%) based on previous sources of dietary advice and preferences for obtaining information were assessed using t test or Mann-Whitney U test. Results Demographic and information source questions were completed by 410 athletes; 331 also completed NK questions. Athletes were mostly non-elite (76%) and AF players (79%). Forty-four per cent of athletes reported having previously received advice from a dietitian. Twenty per cent, 19% and 16% of athletes chose “dietitian,” “internet” and “nutritionist” as their preferred source of nutrition information, respectively. Athletes preferred information on sports nutrition (35%), individual consultations (33%), and information on general healthy eating (33%), over cooking classes (4%) and group presentations (3%). There were no significant associations between preferred and previous information sources and NK scores. Conclusions Australian athletes prefer dietitians, the internet and nutritionists for sports nutrition information. There is an interest in and need for access to a qualified sports dietitian and reputable internet-based nutrition information. Education programs and advice given to athletes need to be evaluated

    The HF-CGM study: An analysis of cardiogoniometric axes in patients with cardiac resynchronization therapy

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    Goal: The HF-CGM is a proof-of-principle study to investigate whether cardiogoniometry (CGM), a three-dimensional electrocardiographic method, can differentiate between pacing modes in patients with cardiac resynchronization therapy (CRT). Methods: At a tertiary cardiology center, CGM recordings were performed using four pacing modes: no pacing; right ventricular (RV) pacing; left ventricular (LV) pacing, and biventricular (BIV) pacing. Three orthogonal CGM planes orientated to the long axis (XY), the frontal plane (YZ), and the short axis (XZ) of the heart were constructed, and the direction of the QRS-axis was calculated for each pacing mode in each plane. During BIV pacing, the direction of CGM QRS-axis was compared between patients with optimal and nonoptimal 12-lead pacing variables. Results: Twenty-two participants (aged 71.5 ± 10.8; 77.3% male, LVEF 29 ± 7%) were consecutively recruited. Only QRS-axis measured in the XY plane could significantly distinguish between all three pacing modes versus no pacing. Mean QRS-axis in the XY plane with pacing off and during RV pacing was leftward and basal; LV pacing was apical; and BIV pacing was rightward and basal. There was a statistically significant difference in the direction of the QRS-axis between patients with optimal versus nonoptimal paced QRS morphology in the XY plane (rightward and basal versus inconsistent). Significance : CGM recorded in the XY plane can accurately detect differences between ventricular pacing sites. It may also be able to identify patients with a CRT device in situ who have optimal response

    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 μg/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 μg/L in 443, 0.04-1.0 μg/L in 435, =0.03 μg/L in 19 and not recorded in 37. A further 823 patients had TnT > 0.03 μg/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

    Improved Heterojunction Quality in Cu2O-based Solar Cells Through the Optimization of Atmospheric Pressure Spatial Atomic Layer Deposited Zn1-xMgxO.

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    Atmospheric pressure spatial atomic layer deposition (AP-SALD) was used to deposit n-type ZnO and Zn1-xMgxO thin films onto p-type thermally oxidized Cu2O substrates outside vacuum at low temperature. The performance of photovoltaic devices featuring atmospherically fabricated ZnO/Cu2O heterojunction was dependent on the conditions of AP-SALD film deposition, namely, the substrate temperature and deposition time, as well as on the Cu2O substrate exposure to oxidizing agents prior to and during the ZnO deposition. Superficial Cu2O to CuO oxidation was identified as a limiting factor to heterojunction quality due to recombination at the ZnO/Cu2O interface. Optimization of AP-SALD conditions as well as keeping Cu2O away from air and moisture in order to minimize Cu2O surface oxidation led to improved device performance. A three-fold increase in the open-circuit voltage (up to 0.65 V) and a two-fold increase in the short-circuit current density produced solar cells with a record 2.2% power conversion efficiency (PCE). This PCE is the highest reported for a Zn1-xMgxO/Cu2O heterojunction formed outside vacuum, which highlights atmospheric pressure spatial ALD as a promising technique for inexpensive and scalable fabrication of Cu2O-based photovoltaics.The authors acknowledge the support of the Cambridge Overseas and Commonwealth Trust, the Rutherford Foundation of New Zealand, Girton College Cambridge. This work has been funded by ERC Advanced Investigator Grant, Novox, ERC-2009-adG247276 and by the EPSRC (under RGS3717)

    Maintaining surface-phase purity is key to efficient open air fabricated cuprous oxide solar cells

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    This is the final published version. It first appeared at http://scitation.aip.org/content/aip/journal/aplmater/3/2/10.1063/1.4913442.Electrochemically deposited Cu 2O solar cells are receiving growing attention owing to a recent doubling in efficiency. This was enabled by the controlled chemical environment used in depositing doped ZnO layers by atomic layer deposition, which is not well suited to large-scale industrial production. While open air fabrication with atmospheric pressure spatial atomic layer deposition overcomes this limitation, we find that this approach is limited by an inability to remove the detrimental CuO layer that forms on the Cu 2O surface. Herein, we propose strategies for achieving efficiencies in atmospherically processed cells that are equivalent to the high values achieved in vacuum processed cells.The authors acknowledge funding from the Cambridge Commonwealth, European and International Trusts (R.L.Z.H. and Y.I.), Rutherford Foundation of New Zealand (R.L.Z.H.), an NSF Graduate Research Fellowship (R.E.B.), EPSRC of the UK (S.H.), University of Cambridge EPSRC Centre for Doctoral Training in Nanoscience (S.H.), Girton College Cambridge (K.P.M.), an NSF CAREER Award ECCS-1150878 (T.B.), the National Research Foundation Singapore through the Singapore Massachusetts Institute of Technology Alliance for Research and Technology’s Low Energy Electronics Systems research program (T.B.), and an ERC Advanced Investigator Grant, Novox, ERC-2009-adG247276 (J.L.D.)
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