Disorientation angle

The energy of such high-angle grain boundaries is not strongly dependent on the disorientation angle. It is, however, noteworthy that drastic... 

Fig. 1-11. Schematic drawing of a grain boundary corresponding to a small disorientation angle 0 (a) specific free energy, agb, as a function of the disorientation angle 0 (b)...

Fig. 8.6 Transmission electron microscopy images of refined grain structure, (b) Results of convergent beam electron diffraction analysis from the lower stir zone corresponding to region 4 in Fig. 8.3. Crain boundaries are delineated by various lines, depending on grain-to-grain disorientation angle thick for 6 > 40°, thin for 1 5° < 6 < 40°, and dotted for 0 < 1 5°, respectively.

The results are described of a study of the relationship between the reflection intensity of x rays and the degree of perfection of crystals used in focusing monochtomatois. An expression has been obtained which gives the variation in the intensity with the integrated reflection width and the size of the focus of the radiation source. Analytical conditions ate presented for estimating the optimal mosaic parameters (size and disorientation angle of the blocks), which the monochromator crystal should satisfy to obtain the maximum reflection intensity. 

Figure 6.1 (a) Schematic microstmcture of a tempered martensitic steel, for example, steel grade 91 [14], Low-angle boundaries are drawn in dashed lines (in practice disorientation angle less than 5 degrees) while the other boundaries are shown by continuous lines (block boundaries, packet boundaries, former austenitic boundaries) (b) Initial microstmcture (TEM) [18],... 

Fig. 4 Definition of the disorientation angle d and the bond angles of the linking groups (X) used in the RIS analysis (a) carbonate, (b) ether, and (c) ester. The tilting angles (jt) between the first bond of the spacer and the mesogenic core axis (bold lines) are estimated to be 21.3°, 5.3°, and 8°, respectively, for the carbonate, ether, and ester group...

Legendre polynomial of (cos (p where

chain axis and the director. It can range from 0 for random orientation to 1 for perfect parallel orientation. Order parameters for nematic solutions of PpBA in N,N-dimethylacetamide + 3% (w/w) LiCl were determined in the composition range extending from the lower limit for stability of the pure mesophase, which is just below the critical concentration, to the solubility limit of the polymer. The experimental values of the order parameter, ranging from 0-76 to 0 83, were found to lie between the theoretical predictions of Doi and those of Flory and Ronca. ... 

The distribution of particle orientations about the fiber axis can be defined in terms of a disorientation function, N(a), where N(o)dfi/4n is the probability of the axis of a particle being at an angle a to the fiber axis in an element of solid angle dU. For a Gaussian distribution of particle orientations,... 

In the classical model the inefficiency of purely disorienting elastic collisions can easily be understood if one takes into account the fact that such disorientation is connected with a turn of the angular momentum J by a tangible angle (collisional randomization of 3(0,rotational level, i.e. the collision becomes an inelastic one. 

The X-ray diffraction measurements result in a numerical parameter (sin2 angle between the chain axis, being parallel to the symmetry axis of the crystallite, and the fibre axis, (sin2 orientation distribution parameter. It has a zero value for ideal orientation and is equal to one in the case of isotropy ("ideal disorientation"). 

Conventional lattice methods can be adapted to treatment of a system of rigid, rodlike particles, or molecules, by the device illustrated in Fig. 1 The particle shown in Fig. la is oriented at an angle t with respect to the preferred axis of the surrounding domain. One of the principal axes of the cubic lattice is aligned with this axis. The particle comprises x isodiametric segments, each of a size that will occupy one cell of the lattice it follows that x so defined is also the axial ratio of the particle. In order to accommodate the particle on the lattice when it is oriented as in Fig. 1 a, we imagine it to be subdivided into y sequences of segments as represented in Fig. 1 b, with each sequence oriented parallel to the preferred axis. The parameter y serves as a measure of disorientation of the particle with respect to the domain axis see Fig. lb. 

For many purposes, it is more convenient to characterize the rotary Brownian movement by another quantity, the relaxation time t. We may imagine the molecules oriented by an external force so that the a axes are all parallel to the x axis (which is fixed in space). If this force is suddenly removed, the Brownian movement leads to their disorientation. The position of any molecule after an interval of time may be characterized by the cosine of the angle between its a axis and the x axis. (The molecule is now considered to be free to turn in any direction in space —its motion is not confined to a single plane, but instead may have components about both the b and c axes.) When the mean value of cosine for the entire system of molecules has fallen to ile(e — 2.718... is the base of natural logarithmus), the elapsed time is defined as the relaxation time r, for motion of the a axis. The relaxation time is greater, the greater the resistance of the medium to rotation of the molecule about this axis, and it is found that a simple reciprocal relation exists between the three relaxation times, Tj, for rotation of each of the axes, and the corresponding rotary diffusion constants defined in equation (i[Pg.138]

The most common adverse reactions of scopolamine are dry mouth, drowsiness, transient impairment of accommodation including mydriasis and blurred vision. The infrequent adverse reactions of scopolamine, especially in higher-than-therapeutic doses, include disorientation, memory disturbances, dizziness, restlessness, hallucinations, confusion, difficulty urinating, rashes or erythema, acute narrow-angle glaucoma, and dry, itchy, or red eyes. 

L is the average size of the mosaic blocks ]/ 2n(p is the average angle of disorientation of the blocks Q <=/Q is the reflectivity of the crystal when account is taken of primary extinction. 

The optimum angle of disorientation between the mosaic blocks may be estimated from the optimum integrated width of the reflection curve. Putting the values of B and (w in Eq. 

The range of optimum values for the average angle of disorientation of the blocks at vg = 3 10 is 2—6. However, if it is necessary to obtain narrower monochromatic beams, crystals having the lowest angle of disorientation within this range must be chosen. 

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