Stresses anisotropy

Mirzamaani et al. [74, 75] point out that the earlier studies of the interrelationships between structure and magnetics have examined films substantially thicker than those now being used in thin-film disks. These authors have examined very thin CoP films and have studied the relative roles of shape anisotropy, stress anisotropy, and crystal anisotropy in determining the magnetic properties. For their CoP-deposition system, shape anisotropy dominated the other factors in determining the film magnetic properties. The shape anisotropy of a particular deposit was determined by the surface condition of the substrate on which the CoP was deposited. 

Stress anisotropy, in ferrites, 77 62-64 Stress-corrosion cracking (SCC), 7 810, 812, 23 301... 

Next, the step-mobilityof Si(OOl) is estimated at lower temperatures, T 500°C, from the experiments of Webb et al. [25] on the relaxation kinetics of non-equilibrium step-spacings. In this experiment, the average terrace size was large, and therefore, due to the stress anisotropy of the 2 x 1 surface reconstruction, a long range interaction of the form... 

Surface sizing can induce structural changes in the paper sheet185 due to the interaction of water sorption (which causes a relaxation of internal stresses) and machine direction tension (which increases anisotropy and creates additional stresses). Anisotropy can be lowered by reducing tension on the web during sheet passage... 

Magnetisation processes are affected by stress. These phenomena, which can be considered as the opposite of magnetostriction, can also be visualised on the basis of spin-orbit coupling. The application of a stress affects the ability of orbitals to rotate under the influence of a magnetic field. Stress effects can be expressed in terms of a stress anisotropy,... 

According to the Doi-Edwards theory, after time t = Teq following a step deformation at t = 0, the stress relaxation is described by Eqs. (8.52)-(8.56). In obtaining these equations, it is assumed that the primitive-chain contour length is fixed at its equilibrium value at all times. And the curvilinear diffusion of the primitive chain relaxes momentarily the orientational anisotropy (as expressed in terms of the unit vector u(s,t) = 5R(s,t)/9s), or the stress anisotropy, on the portion of the tube that is reached by either of the two chain ends. The theory based on these assumptions, namely, the Doi-Edwards theory, is called the pure reptational chain model. In reality, the primitive-chain contour length should not be fixed, but rather fluctuates (stretches and shrinks) because of thermal (Brownian) motions of the segments. 

C. Representation of fractures to incorporate stress anisotropy Numerically it is critical to consider an appropriate representation of the Iractuies and this representation should result into stress anisotropy. This stress anisotropy is essential forthe fiacturespropaga-tion. Rocks are heterogeneous in nature and a fracture created by blasting enhances this heterogeneity, which ultimately contributes in the fractures propagation. 

D average local uniaxial anisotropy in the st stress anisotropy... 

As outlined above it is clear that for the R/T where R atoms have orbital angular momentum, the PMA results from the single-ion anisotropy of R atoms and structural anisotropy in the interface region. In the next subsection, a theoretical expression for PMA is derived based on this concept. It is also essential to point out that the stress anisotropy and BOA have been involved in the PMA induced by the distortion of the structure from the strains in the films. Once the distorted structure is determined, this will then affect the magnitude of both the structure anisotropy and the interactions among all R and T atoms and consequently the PMA behavior. 

Hyunil Jo, EhD, Baker Hughes. 2013. Optimal fracture spacing of a hydraulically fractured horizontal wellbore to induce complex fractures in a reservoir under high-situ stress anisotropy. SPE. 16717. 

Den Toonder and co-workers (64,86), and Massah and Hanratty (87) examined the role of viscoelasticity, extensional viscosity, and stress anisotropy in drag reduction. Direct numerical simulation (DNS) investigation of Den Toonder and co-workers (86) points out that drag increases rather than decreases when the elastic contributions are taken into account. 

Yamamoto, T., Igarashi, H., and Okazaki, K., Internal Stress Anisotropies Induced by Electric Field in Lanthanum Modified PbTiOs Ceramics, Ferroeletrics, 1983, 50, 273 278. 

In the literature, high coercivity values closer to the theoretical ones have been found in a few cases for dispersed y-Fe20s particles, but the mechanisms of such coercivities are still not clear. Several arguments have been reported to explain the coercivity enhancement, such as surface anisotropy [37] or stress anisotropy induced either by the presence of a Fe304-y-Fe203 solid solution, whose differences in lattice constants produce stress [38] or, in thin films, by the differences in thermal expansion coefficients between the film and the substrate [39]. 

The stress anisotropy is additionally affected by the budding, which makes the a component more tensile by 0.5 Nm because the parallel component of the buckled dimer is shortened and therefore pulls stronger on the backbonds. The ffi component becomes by 1.2 Nm less compressive because the up-atom dehybridizes toward sp, which is accompanied by a change in the angle between p orbitals to 107°, less than the angle between the backbonds of the up-atoms. In total, the stress anisotropy An = cr — crj. decreases to 1.7 Nm [38, 40]. 

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