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Bernard Barbara - One of the best experts on this subject based on the ideXlab platform.

  • Field and temperature dependence of the Anisotropy Ratio in a high-Tc superconductor
    Europhysics Letters (EPL), 1996
    Co-Authors: P. Pugnat, Gérard Fillion, Henri Noël, Bernard Barbara
    Abstract:

    Using a double SQUID magnetometer, the angular dependence of the transverse (MT) and longitudinal (ML) components of the magnetization vector have been measured simultaneously on a YBa2Cu3O7 − δ (Tc ≈ 91 K) and on a La1.85Sr0.15CuO4 (Tc ≈ 35 K) single crystal. The reversible and irreversible contributions of each component of the magnetization can be separated. The angular variations of the Ratio of the reversible components MTrev/MLrev have been analysed with the 3D anisotropic Ginzburg-Landau theory. The derived Anisotropy factor γ is found to depend on the applied field. In YBa2Cu3O7 − δ, this behaviour is attributed to field-induced reduction of the proximity effect of non-superconducting layers. In quasi-2D La1.85Sr0.15CuO4, this interpretation is not relevant and our data show rather the lock-in transition of the vortex lines.

  • Magnetic measurements of the Anisotropy Ratio in YBa2Cu3O7−δ
    Physica C-superconductivity and Its Applications, 1994
    Co-Authors: P. Pugnat, Gérard Fillion, Bernard Barbara, S. Khène, Henri Noël
    Abstract:

    Abstract The angular dependence of both, transverse (MT) and longitudinal (ML) components of the magnetization vector have been measured simultaneously on a YBa2Cu3O7−δ single crystal (Tc≈91 K). In order to minimize shape effects, a cylindrical form was adopted for our crystal with the c -axis lying in the circular section. The irreversible contribution of each component was subtracted to deduce the Ratio of the reversible components MTrev/MLrev. The interpretation of the angular dependence of this Ratio with the 3-Dimensional Anisotropic Ginzburg Landau theory allowed us to determine the square root of the effective masses Ratio γ≈8.3±0.5 at T = 90.5 K.

  • magnetic measurements of the Anisotropy Ratio in yba2cu3o7 δ
    Physica C-superconductivity and Its Applications, 1994
    Co-Authors: P. Pugnat, Gérard Fillion, Bernard Barbara, S. Khène, Henri Noël
    Abstract:

    Abstract The angular dependence of both, transverse (MT) and longitudinal (ML) components of the magnetization vector have been measured simultaneously on a YBa2Cu3O7−δ single crystal (Tc≈91 K). In order to minimize shape effects, a cylindrical form was adopted for our crystal with the c -axis lying in the circular section. The irreversible contribution of each component was subtracted to deduce the Ratio of the reversible components MTrev/MLrev. The interpretation of the angular dependence of this Ratio with the 3-Dimensional Anisotropic Ginzburg Landau theory allowed us to determine the square root of the effective masses Ratio γ≈8.3±0.5 at T = 90.5 K.

Heidilynn Ploeg - One of the best experts on this subject based on the ideXlab platform.

  • dependence of human lumbar vertebral trabecular bone hvtb mechanical Anisotropy Ratio on qct based apparent density
    Volume 1A: Abdominal Aortic Aneurysms; Active and Reactive Soft Matter; Atherosclerosis; BioFluid Mechanics; Education; Biotransport Phenomena; Bone J, 2013
    Co-Authors: Ameet K Aiyangar, Juan Vivanco, Paul A Anderson, Everett L Smith, Heidilynn Ploeg
    Abstract:

    Obtaining bone mechanical properties from clinical resolution quantitative computed tomography (QCT)-derived localized apparent density presents the most attractive, available tool for developing subject-specific finite element (FE) bone models. While QCT density is a good predictor of the mechanical properties of HVTB [1, 2], knowledge of the fabric tensor (Anisotropy Ratio) can substantially improve prediction [3] and accuracy of CT-based continuum FE models [4]. Unfortunately, resolution of currently available clinical CT scanners is inadequate for mapping the fabric tensor of HVTB, which is known to be at least transversely isotropic [5]. Furthermore, trabecular bone mechanical Anisotropy Ratio has been shown to vary with density [2].Copyright © 2013 by ASME

  • Dependence of Human Lumbar Vertebral Trabecular Bone (HVTB) Mechanical Anisotropy Ratio on QCT–Based Apparent Density
    Volume 1A: Abdominal Aortic Aneurysms; Active and Reactive Soft Matter; Atherosclerosis; BioFluid Mechanics; Education; Biotransport Phenomena; Bone J, 2013
    Co-Authors: Ameet K Aiyangar, Juan Vivanco, Paul A Anderson, Everett L Smith, Heidilynn Ploeg
    Abstract:

    Obtaining bone mechanical properties from clinical resolution quantitative computed tomography (QCT)-derived localized apparent density presents the most attractive, available tool for developing subject-specific finite element (FE) bone models. While QCT density is a good predictor of the mechanical properties of HVTB [1, 2], knowledge of the fabric tensor (Anisotropy Ratio) can substantially improve prediction [3] and accuracy of CT-based continuum FE models [4]. Unfortunately, resolution of currently available clinical CT scanners is inadequate for mapping the fabric tensor of HVTB, which is known to be at least transversely isotropic [5]. Furthermore, trabecular bone mechanical Anisotropy Ratio has been shown to vary with density [2].Copyright © 2013 by ASME

Guangkeng Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Sensitivity Analyses of the Seepage and Stability of Layered Rock Slope Based on the Anisotropy of Hydraulic Conductivity: A Case Study in the Pulang Region of Southwestern China
    Water, 2020
    Co-Authors: Chengzhi Xia, Dongxin Bai, Ziqiang Zhu, Shuai Luo, Guangkeng Zhang
    Abstract:

    In the study of the seepage characteristics of layered rock slope under rainfall conditions, the majority of previous research has considered the hydraulic conduction to be isotropic, or only considered the Anisotropy Ratio of the hydraulic conductivity, ignoring the Anisotropy angle. In the current study, a layered rock slope in the Pulang region was selected as an example. Then, based on the fitting parameters of the Van Genuchten model, pore water pressure sensitivity analyses of the layered rock slope were carried out. The Anisotropy Ratio and Anisotropy angle were used to analyze the sensitivity of the seepage and stability of the layered rock slopes. The results show that as the Anisotropy angle of hydraulic conductivity of layered rock slope decreased, the maximum volume water content of surface (MWCS) of layered rock slope gradually increased. Additionally, as the Anisotropy Ratio decreased and the Anisotropy angle increased, the rising heights of the groundwater (RHG) of layered rock slope gradually increased. When the hydraulic conduction of layered rock slope was considered isotropic, the factor of safety (FS) tended to be overestimated. As the Anisotropy Ratio decreased and the Anisotropy angle increased, the factor of safety (FS) of layered rock slope decreased. Prevention should be the objective for rock slopes with larger dip angles in the bedding plane in the Pulang region. This study provides feasible schemes for the evaluation of the seepage and stability of layered rock slopes in Pulang region of southwestern China.

David B Burr - One of the best experts on this subject based on the ideXlab platform.

  • elastic Anisotropy and collagen orientation of osteonal bone are dependent on the mechanical strain distribution
    Journal of Orthopaedic Research, 1999
    Co-Authors: Y Takano, Charles H Turner, I Owan, R B Martin, M R Forwood, David B Burr
    Abstract:

    : There is evidence that the collagen microarchitecture of bone is influenced by mechanical stresses or strains. We hypothesized that peak functional strains correlate with the elastic Anisotropy and collagen orientation of bone tissue and that the bone Anisotropy might be changed by altering the strain patterns in canine radii for 12 months. We tested these hypotheses in studies using nine adult foxhounds. The baseline group (n = 3) had three rosette strain gauges placed around the midshaft of the radius, and strain distributions were measured during walking. The osteotomy group (n = 3) had 2 cm of the ulna surgically removed, and the sham group (n = 3) received a sham osteotomy. The osteotomy and sham groups were allowed free movement in cages with runs for 12 months, after which strain distributions were measured on the radii during walking. Bone-tissue Anisotropy and collagen architecture were measured in radii from which the in vivo longitudinal strain patterns had been measured. The collagen birefringence patterns were measured with use of a circularly polarized light technique, and the elastic Anisotropy of the bone, mineral, and collagen matrix was evaluated with a novel acoustic microscopy technique. Peak longitudinal strains in the radius correlated with the normalized longitudinal structure index (a polarized light measure of collagen birefringence) and the tissue Anisotropy Ratio. The average Anisotropy Ratio was 1.28+/-0.01 in the posterior (compressive) cortex and 1.43+/-0.01 in the anterior (tensile) cortex (these values are significantly different at p < 0.0001). The ulnar osteotomy changed the strain pattern on the radius, causing increased tensile strains in the medial cortex by more than 5-fold that were associated with a significant increase in the Anisotropy Ratio in the bone tissue. The longitudinal structure index was strongly correlated (r = 0.62, p < 0.005) with the Anisotropy Ratio of demineralized bone but was not correlated with that of deproteinized bone; this indicates that it reflects collagen fibril orientation in the bone matrix. These results indicate that mechanical strains affect both collagen and mineral microarchitecture in bone tissue, i.e., tensile strains are associated with increased tissue Anisotropy and compressive strains, with decreased Anisotropy.

Wenwei Zhu - One of the best experts on this subject based on the ideXlab platform.

  • Seepage, Deformation, and Stability Analysis of Sandy and Clay Slopes with Different Permeability Anisotropy Characteristics Affected by Reservoir Water Level Fluctuations
    Water, 2020
    Co-Authors: Xuhua Ren, Jixun Zhang, Haijun Wang, Junlei Wang, Wenwei Zhu
    Abstract:

    Evaluation of slope stability under water level fluctuations is an important topic in the Three Gorges Reservoir (TGR) in China. However, most of the previous studies regarded slope soil as isotropic material, or only considered the influence of Anisotropy Ratio (kr = kx/ky) but ignored the Anisotropy direction (α). Meanwhile, the pore pressure–stress coupling was rarely considered in the previous numerical simulations. In the present study, the SIGMA/W and SLOPE/W modules in Geo-studio are utilized to carry out the numerical simulation of Caipo slope under the drawdown of the reservoir water level, and the Anisotropy Ratio (kr) as well as the Anisotropy direction (α) of two kinds of soils (clay and sand) are included. Results show that the Anisotropy Ratio kr and Anisotropy direction α decrease the infiltRation capacity of the soil, which increases the infiltRation line hysteretic elevation (ILHE) as well as maximum horizontal displacement (MHD), and reduces the minimum safety factor (MSF). The slope toe firstly fails with the drawdown of water level. The influence of reservoir water level drop on seepage, deformation, and stability of the sand slope is less than that of the clay slope. For the sandy soil slope, it is not only necessary to consider the influence of kr, but also the influence of α. For the soil slope, we can only consider α in order to simplify calculation.