Anisotropy reducing

Another aspect that is interesting to note concerns the dependence of the DFT gap on the orientation of the wire, indeed, for each wire size the following relation holds g[100] > g[lll] > Eg [110]. As has been pointed out in Ref. [121], this is related to the different geometrical structure of the wires in the [100], [111] and [110] directions. Indeed the [100], [111] wires appear as a collection of small clusters connected along the axis, while the [110] wires resemble a linear chain. So we expect that quantum confinement effects are much bigger in the [100], [111] wires, due to their quasi zero-dimensionality, with respect to the [110] wires. Further, the orientation anisotropy reduces with the wire width and it is expected to disappear for very large wires, where the band gap approaches that of the bulk material. 

The number of terms (up to five, but only three of them independent) and values of pre-exponential factor A, depend on the fluorophore symmetry and on the orientations of and in the molecule. The rotation correlation times, Tc,i, reflect the main components of the gyration tensor only. For the parallel orientation of both dipole moments, the initial anisotropy in a fluid system has the highest possible value, ro = A = 0.4. In the case of a spherical rotor, fluorescence anisotropy reduces to a single exponential function. For a symmetric rotor, r t) is either single-or double-exponential, depending on the orientation of dipole moments with respect to the long axis. 

Thus, low threshold voltage can be obtained by either enhancing the dielectric anisotropy, reducing the elastic constant, or a combination of both. However, a smaller elastic constant slows down the response time because of the weaker restoring torque. 

The bearings are not the only source of destabilization in rotating systems, an important mechanism being that of rotary damping (14). The effect of rotary damping is to reduce the speed of onset of instability in relation to the lowest system frequency - loosely called the first critical speed. Smith (15) first showed that bearing anisotropy reduces instability... 

The second-order quadnipolar broadening of tire - transition can be further reduced by spiiming at an angle other than 54.7° (VAS), the width being a minimum between 60-70°. The reduction is only 2 however, and dipolar and shift anisotropy broadening will be reintroduced, thus VAS has only found limited application. 

Mechanical Properties and Structural Performance. As a result of the manufacturing process, some cellular plastics have an elongated cell shape and thus exhibit anisotropy in mechanical, thermal, and expansion properties (35,36). Efforts are underway to develop manufacturing techniques that reduce such anisotropy and its effects. In general, higher strengths occur for the paraHel-to-rise direction than in the perpendicular-to-rise orientation. Properties of these materials show variabiUty due to specimen form and position in the bulk material and to uncertainty in the axes with respect to direction of foam rise. Expanded and molded bead products exhibit Httie anisotropy. 

Densification to what is practically hiU density is achievable for most materials. The resulting mechanical properties are equivalent to wrought parts in similar condition. In some materials, the properties of the HIP product are superior because of reduced anisotropy. 

This gives a maximum ratio of 43, which is more than enough. In fact, to bring the anisotropy down to the target figure of 16 we need to reduce the volume fraction of fibres to only 0.13 ... 

Such is the anisotropy that flexural modulus may be four times as high in the flow direction as in the transverse directions. This difference may be reduced by incorporating fillers such as glass fibre or mica. 

Although the Izod and Charpy tests are widely used for plastics, other types of test are also popular. These include tensile impact tests and flexural plate (falling weight) tests. The latter is particularly useful in situations where the effects of flow anisotropy are being assessed. In addition, arbitrary end-product tests are widely used to provide reassurance that unforseen factors have not emerged to reduce the impact performance of the product. 

The barium ferrite was found to have an increase in magnetic anisotropy, as in the nickel ferrite, but its overall effect on magnetization was less because of greater magnetocrystalline anisotropy. The shock modification caused reduced crystallite size and local damage that resulted in increased microwave absorption. 

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