The Experts below are selected from a list of 126 Experts worldwide ranked by ideXlab platform

Dominic Orth - One of the best experts on this subject based on the ideXlab platform.

  • the role of Textured Material in supporting perceptual motor functions
    PLOS ONE, 2013
    Co-Authors: Dominic Orth, Keith Davids, Jonathan Wheat, Ludovic Seifert, Jarmo Liukkonen, Timo Jaakkola, Derek Ashford, Graham K Kerr
    Abstract:

    Simple deformation of the skin surface with Textured Materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of Textured Materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD = 0.28, 95%CI = 0.46–0.09, Z = 2.99, P = 0.001; Tau2 = 0.02; Chi2 = 9.87, df = 6, P = 0.13; I2 = 39.22). Significant heterogeneity was found in, the overall effect of texture: Tau2 = 0.13; Chi2 = 130.71, df = 26, P<0.0001; I2 = 85.98%, pooled samples in upright balance tasks: Tau2 = 0.09; Chi2 = 101.57, df = 13, P<0.001; I2 = 72.67%, and in elderly in upright balance tasks: Tau2 = 0.16; Chi2 = 39.42, df = 5, P<0.001; I2 = 83.05%. No effect was shown for walking tasks: Tau2 = 0.00; Chi2 = 3.45, df = 4, P = 0.27, I2 = 22.99%. Data provides unequivocal support for utilizing Textured Materials in young healthy populations for improving perceptual-motor performance. Future research is needed in young healthy populations under conditions where visual and proprioceptive information is challenged, as in high-speed movements, or where use of equipment mediates the performer-environment interaction or where dysfunctional information sources ‘compete’ for attention. In elderly and ailing populations data suggests further research is required to better understand contexts where texture can facilitate improved perceptual-motor performance.

  • The Role of Textured Material in Supporting Perceptual-Motor Functions
    PLOS ONE, 2013
    Co-Authors: Dominic Orth, Keith Davids, Jonathan Wheat, Ludovic Seifert, Jarmo Liukkonen, Timo Jaakkola, Derek Ashford, Graham K Kerr
    Abstract:

    Simple deformation of the skin surface with Textured Materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of Textured Materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD = 0.28, 95%CI = 0.46–0.09, Z = 2.99, P = 0.001; Tau2 = 0.02; Chi2 = 9.87, df = 6, P = 0.13; I2 = 39.22). Significant heterogeneity was found in, the overall effect of texture: Tau2 = 0.13; Chi2 = 130.71, df = 26, P

Graham K Kerr - One of the best experts on this subject based on the ideXlab platform.

  • the role of Textured Material in supporting perceptual motor functions
    PLOS ONE, 2013
    Co-Authors: Dominic Orth, Keith Davids, Jonathan Wheat, Ludovic Seifert, Jarmo Liukkonen, Timo Jaakkola, Derek Ashford, Graham K Kerr
    Abstract:

    Simple deformation of the skin surface with Textured Materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of Textured Materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD = 0.28, 95%CI = 0.46–0.09, Z = 2.99, P = 0.001; Tau2 = 0.02; Chi2 = 9.87, df = 6, P = 0.13; I2 = 39.22). Significant heterogeneity was found in, the overall effect of texture: Tau2 = 0.13; Chi2 = 130.71, df = 26, P<0.0001; I2 = 85.98%, pooled samples in upright balance tasks: Tau2 = 0.09; Chi2 = 101.57, df = 13, P<0.001; I2 = 72.67%, and in elderly in upright balance tasks: Tau2 = 0.16; Chi2 = 39.42, df = 5, P<0.001; I2 = 83.05%. No effect was shown for walking tasks: Tau2 = 0.00; Chi2 = 3.45, df = 4, P = 0.27, I2 = 22.99%. Data provides unequivocal support for utilizing Textured Materials in young healthy populations for improving perceptual-motor performance. Future research is needed in young healthy populations under conditions where visual and proprioceptive information is challenged, as in high-speed movements, or where use of equipment mediates the performer-environment interaction or where dysfunctional information sources ‘compete’ for attention. In elderly and ailing populations data suggests further research is required to better understand contexts where texture can facilitate improved perceptual-motor performance.

  • The Role of Textured Material in Supporting Perceptual-Motor Functions
    PLOS ONE, 2013
    Co-Authors: Dominic Orth, Keith Davids, Jonathan Wheat, Ludovic Seifert, Jarmo Liukkonen, Timo Jaakkola, Derek Ashford, Graham K Kerr
    Abstract:

    Simple deformation of the skin surface with Textured Materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of Textured Materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD = 0.28, 95%CI = 0.46–0.09, Z = 2.99, P = 0.001; Tau2 = 0.02; Chi2 = 9.87, df = 6, P = 0.13; I2 = 39.22). Significant heterogeneity was found in, the overall effect of texture: Tau2 = 0.13; Chi2 = 130.71, df = 26, P

Keith Davids - One of the best experts on this subject based on the ideXlab platform.

  • the role of Textured Material in supporting perceptual motor functions
    PLOS ONE, 2013
    Co-Authors: Dominic Orth, Keith Davids, Jonathan Wheat, Ludovic Seifert, Jarmo Liukkonen, Timo Jaakkola, Derek Ashford, Graham K Kerr
    Abstract:

    Simple deformation of the skin surface with Textured Materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of Textured Materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD = 0.28, 95%CI = 0.46–0.09, Z = 2.99, P = 0.001; Tau2 = 0.02; Chi2 = 9.87, df = 6, P = 0.13; I2 = 39.22). Significant heterogeneity was found in, the overall effect of texture: Tau2 = 0.13; Chi2 = 130.71, df = 26, P<0.0001; I2 = 85.98%, pooled samples in upright balance tasks: Tau2 = 0.09; Chi2 = 101.57, df = 13, P<0.001; I2 = 72.67%, and in elderly in upright balance tasks: Tau2 = 0.16; Chi2 = 39.42, df = 5, P<0.001; I2 = 83.05%. No effect was shown for walking tasks: Tau2 = 0.00; Chi2 = 3.45, df = 4, P = 0.27, I2 = 22.99%. Data provides unequivocal support for utilizing Textured Materials in young healthy populations for improving perceptual-motor performance. Future research is needed in young healthy populations under conditions where visual and proprioceptive information is challenged, as in high-speed movements, or where use of equipment mediates the performer-environment interaction or where dysfunctional information sources ‘compete’ for attention. In elderly and ailing populations data suggests further research is required to better understand contexts where texture can facilitate improved perceptual-motor performance.

  • The Role of Textured Material in Supporting Perceptual-Motor Functions
    PLOS ONE, 2013
    Co-Authors: Dominic Orth, Keith Davids, Jonathan Wheat, Ludovic Seifert, Jarmo Liukkonen, Timo Jaakkola, Derek Ashford, Graham K Kerr
    Abstract:

    Simple deformation of the skin surface with Textured Materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of Textured Materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD = 0.28, 95%CI = 0.46–0.09, Z = 2.99, P = 0.001; Tau2 = 0.02; Chi2 = 9.87, df = 6, P = 0.13; I2 = 39.22). Significant heterogeneity was found in, the overall effect of texture: Tau2 = 0.13; Chi2 = 130.71, df = 26, P

J. Gibmeier - One of the best experts on this subject based on the ideXlab platform.

  • Incremental Hole Drilling for Residual Stress Analysis of Strongly Textured Material States – A New Calibration Approach
    Experimental Mechanics, 2016
    Co-Authors: S. Schuster, J. Gibmeier
    Abstract:

    Technical components produced via sheet metal forming often obtain characteristic crystallographic textures and process induced residual stress distributions. Knowledge of the local residual stress states is essential for the proper components’ dimensioning. We report about the expansion of the incremental hole drilling technique for residual stress analysis to highly Textured Material states. A new evaluation approach using the differential evaluation algorithm is proposed, which bases on the calculation of multiple case specific calibration functions under consideration of the local orientation distribution function of the Textured Material. Systematic finite element (FE) simulations of incremental hole-drilling experiments are conducted regarding defined ideal nickel single crystal orientations (cube, Goss and brass). Multiple case-specific calibration functions, which consider the Materials elastic anisotropy, are calculated and applied for stress calculation. In addition, the influence of a rosette misorientation between stress measurement and FE calibration is investigated. Using this new evaluation strategy a significant improvement of (residual) stress calculation on strongly Textured Materials is achieved. Finally, the capability of the proposed evaluation approach is experimentally validated for an uniaxially loaded CMSX-4 (nickel base super alloy) single crystal. The investigation clearly proved that in case of strongly anisotropic Materials the evaluation using multiple case-specific calibration functions leads to a significant improvement in stress analysis compared to a conventional evaluation.

  • incremental hole drilling for residual stress analysis of strongly Textured Material states a new calibration approach
    Experimental Mechanics, 2016
    Co-Authors: S. Schuster, J. Gibmeier
    Abstract:

    Technical components produced via sheet metal forming often obtain characteristic crystallographic textures and process induced residual stress distributions. Knowledge of the local residual stress states is essential for the proper components’ dimensioning. We report about the expansion of the incremental hole drilling technique for residual stress analysis to highly Textured Material states. A new evaluation approach using the differential evaluation algorithm is proposed, which bases on the calculation of multiple case specific calibration functions under consideration of the local orientation distribution function of the Textured Material. Systematic finite element (FE) simulations of incremental hole-drilling experiments are conducted regarding defined ideal nickel single crystal orientations (cube, Goss and brass). Multiple case-specific calibration functions, which consider the Materials elastic anisotropy, are calculated and applied for stress calculation. In addition, the influence of a rosette misorientation between stress measurement and FE calibration is investigated. Using this new evaluation strategy a significant improvement of (residual) stress calculation on strongly Textured Materials is achieved. Finally, the capability of the proposed evaluation approach is experimentally validated for an uniaxially loaded CMSX-4 (nickel base super alloy) single crystal. The investigation clearly proved that in case of strongly anisotropic Materials the evaluation using multiple case-specific calibration functions leads to a significant improvement in stress analysis compared to a conventional evaluation.

  • Residual Stress Analysis of Strongly Textured Materials by Means of the Incremental Hole-Drilling Method – Survey on the Application Limits
    Materials Testing-Materials and Components Technology and Application, 2014
    Co-Authors: S. Schuster, J. Gibmeier
    Abstract:

    Abstract In sheet metal forming, residual stress distributions are often accompanied by crystallographic texture. Incremental hole-drilling for stress analysis is only reliably applicable for isotropic Materials. The objective of this study is to determine the influence of texture on residual stress analysis using conventional evaluation methods and to specify the application limits in case of Textured Material states. A systematic finite element simulation study for ideal texture orientations is conducted with respect to the strain gage rosette orientation. The results of the numerical investigations show that reliable stress analysis on strongly Textured Materials is not feasible using the existing evaluation method. The application limits are given for the application of commercially available evaluation software with respect to degree of anisotropy, stress state and strain gage orientation.

Masaya Nakamura - One of the best experts on this subject based on the ideXlab platform.

  • Lead-free piezoceramics
    Nature, 2004
    Co-Authors: Yasuyoshi Saito, Tatsuhiko Nonoyama, Takahiko Homma, Toshiatsu Nagaya, Hisaaki Takao, Toshihiko Tani, Kazumasa Takatori, Masaya Nakamura
    Abstract:

    Lead has recently been expelled from many commercial applications and Materials (for example, from solder, glass and pottery glaze) owing to concerns regarding its toxicity. Lead zirconium titanate (PZT) ceramics are high-performance piezoelectric Materials, which are widely used in sensors, actuators and other electronic devices; they contain more than 60 weight per cent lead. Although there has been a concerted effort to develop lead-free piezoelectric ceramics, no effective alternative to PZT has yet been found. Here we report a lead-free piezoelectric ceramic with an electric-field-induced strain comparable to typical actuator-grade PZT. We achieved this through the combination of the discovery of a morphotropic phase boundary in an alkaline niobate-based perovskite solid solution, and the development of a processing route leading to highly Textured polycrystals. The ceramic exhibits a piezoelectric constant d33 (the induced charge per unit force applied in the same direction) of above 300 picocoulombs per newton (pC N(-1)), and texturing the Material leads to a peak d33 of 416 pC N(-1). The Textured Material also exhibits temperature-independent field-induced strain characteristics.