94 research outputs found

    ANALYSIS OF THE STABILIZING EFFECT OF THE AIRCAST ANKLE BRACE FOR WALKING ALONG AN INCLINED PLANE

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    INTRODUCTION: For functional treatment of acute ankle sprains various ortheses - special shoes and braces - are in use to prevent inversion movements of the ankle while allowing limited dorsi-plantar-flexion movement (Segesser 1986). For the evaluation of ankle orthoses most of the studies use static and quasi-static methods. In contrast to this, only a few studies are available that were made under dynamic or functional conditions (Kimura 1987, StĂźssi 1989, McPoil 1991, Jerosch 1994, Nigg 1995). To compare seven different orthoses under functional conditions, Scheuffelen, Gollhofer and Lohrer (1993) applied controlled inversion movements of 20 and 30 degrees. A significant reduction of the induced inversion displacement was observed in all devices, although a complete inhibition of this movement was not possible. Of the seven different ankle braces, the AIRCAST stirrup offered the best protection against stationary induced inversion displacement, while simultaneously maintaining high functional innervation. Nigg (1995) recommends, on the basis of his examination report, analyzing the functionality of ankle braces with a combination of quasi-static and dynamic movement-tests. In particular, he proposes checking the functionality of orthoses with movement-tasks in real-life situations. Therefore the purpose of this experimental study is the verification of the joint stabilizing effect of the AIRCAST ankle brace for walking on an inclined plane with induced inversion displacement in one foot. If the 'AIRCAST ankle brace' sufficiently protects against inversion movements, a foot walking along an inclined plane cannot take steps as extremely inverted as is the case with an unstabilized foot. Therefore stabilization with the 'AIRCAST ankle brace' should make it possible to walk with less deviation in the heel area

    Phase coexistence and critical temperatures of the (Bi, Pb)2Sr2Ca2Cu3Ox phase under partial pressures of oxygen between 10−3 and 0.21 bar with and without additions of silver

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    We have investigated the stability of the (Bi, Pb)2Sr2Ca2Cu3Ox phase for the stoichiometry (Bi: Pb: Sr:Ca: Cu = 1.72: 0.34: 1.83: 1.97: 3.13), subjecting it to temperatures between 700 and 850 °C under various oxygen partial pressures. A narrow region was found in which Bi, Pb(2223) was the only superconducting phase. This region follows closely the thermal decomposition line. X-ray pure Bi, Pb(2223) will partially decompose if treated outside of the stability region. For a given oxygen partial pressure, the Bi, Pb(2223) phase tends to coexist with the 2201 phase for temperatures above, and the 2212 phase for temperatures below this region. At even lower temperatures an additional lead-rich phase appears. Critical temperatures Tc vary little with treatment and range between 108.5 K and 110.8 K. If 10% silver is added to the starting powder, the phase coexistence regions shift. Silver does not seem to have a significant effect on the absolute values of the critical temperature. The Bi, Pb(2223) thermal decomposition temperature for a given oxygen pressure is lowered by at least 10 K by the presence of A

    Self-organized current transport through low angle grain boundaries in YBa2_2Cu3_3O7−δ_{7-\delta} thin films, studied magnetometrically

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    The critical current density flowing across low angle grain boundaries in YBa2_2Cu3_3O7−δ_{7-\delta} thin films has been studied magnetometrically. Films (200 nm thickness) were deposited on SrTiO3_3 bicrystal substrates containing a single [001] tilt boundary, with angles of 2, 3, 5, and 7 degrees, and the films were patterned into rings. Their magnetic moments were measured in applied magnetic fields up to 30 kOe at temperatures of 5 - 95 K; current densities of rings with or without grain boundaries were obtained from a modified critical state model. For rings containing 5 and 7 degree boundaries, the magnetic response depends strongly on the field history, which arises in large part from self-field effects acting on the grain boundary.Comment: 8 pages, including 7 figure

    On the interpretation of the equilibrium magnetization in the mixed state of high-Tc superconductors

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    We apply a recently developed scaling procedure to the analysis of equilibrium magnetization M(H) data that were obtained for T-2212 and Bi-2212single crystals and were reported in the literature. The temperature dependencies of the upper critical field and the magnetic field penetration depth resulting from our analysis are distinctly different from those obtained in the original publications. We argue that theoretical models, which are usually employed for analyses of the equilibrium magnetization in the mixed state of type-II superconductors are not adequate for a quantitative description of high-Tc superconductors. In addition, we demonstrate that the scaled equilibrium magnetization M(H) curve for a Tl-2212 sample reveals a pronounced kink, suggesting a phase transition in the mixed state.Comment: 9 pages, 5figure

    Central peak position in magnetization loops of high-TcT_c superconductors

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    Exact analytical results are obtained for the magnetization of a superconducting thin strip with a general behavior J_c(B) of the critical current density. We show that within the critical-state model the magnetization as function of applied field, B_a, has an extremum located exactly at B_a=0. This result is in excellent agreement with presented experimental data for a YBCO thin film. After introducing granularity by patterning the film, the central peak becomes shifted to positive fields on the descending field branch of the loop. Our results show that a positive peak position is a definite signature of granularity in superconductors.Comment: $ pages, 6 figure

    Possible superconductivity above 25 K in single crystalline Co-doped BaFe2_{2}As2_{2}

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    We present superconducting properties of single crystalline Ba(Fe0.9_{0.9}Co0.1_{0.1})2_{2}As2_{2} by measuring magnetization, resistivity, upper critical field, Hall coefficient, and magneto-optical images. The magnetization measurements reveal fish-tail hysteresis loop at high temperatures and relatively high critical current density above Jc=105J_{c}=10^{5} A/cm2^{2} at low temperatures. Upper critical field determined by resistive transition is anisotropic with anisotropic parameter ∟\sim 3.5. Hall effect measurements indicate that Ba(Fe0.9_{0.9}Co0.1_{0.1})2_{2}As2_{2} is a multiband system and the mobility of electron is dominant. The magneto-optical imaging reveals prominent Bean-like penetration of vortices although there is a slight inhomogeneity in a sample. Moreover, we find a distinct superconductivity above 25 K, which leads us to speculate that higher transition temperature can be realized by fine tuning Co-doping level.Comment: 4 pages, 5 figure

    Examining outpatients' hand hygiene behaviour and its relation to COVID-19 infection prevention measures

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    BACKGROUND: The increasing demand for outpatient care is associated with a higher risk of infection transmission in these settings. However, there is limited research on infection prevention and control practices in ambulatory clinics, and none focuses on patients. AIM: This study aims to examine outpatients' hand hygiene behaviours, their determinants, and their associations with other infection prevention measures during the COVID-19 pandemic. METHODS: We observed the hand hygiene behaviour of one cohort of patients in one outpatient clinic and surveyed a separate sample in five clinics about their hand hygiene practice in outpatient facilities. A questionnaire based on the Theoretical Domains Framework (TDF) was used to examine predictors of the behaviour. Moreover, patients indicated their compliance with COVID-19 infection prevention measures, vaccination status, disease risk perception, and vaccine hesitancy. FINDINGS: Observed hand hygiene rates among 618 patients were low (12.8%), while 67.3% of the 300 surveyed patients indicated sanitising their hands upon entering the clinic. The TDF domains memory, attention, and decision processes, and emotions significantly predicted both current (today's) and general hand hygiene behaviour in outpatient clinics. Hand hygiene behaviour and compliance with COVID-19 infection prevention showed a positive association; however, no significant connection was found with patients' vaccination status, suggesting different behavioural motivators. CONCLUSION: Hand hygiene among outpatients should be improved through interventions focusing on helping patients remember to clean their hands. More research on infection prevention in outpatient facilities is needed to ensure patient safety
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