Axis Oblique

Pictorial representation is divided into three groups. Two of these groups are demonstrated in this chapter. The three types of pictorial sketches are axonometric (meaning to measure along the axis), oblique, and perspective. Of the axonometric family of drawings, isometric sketching is the one used here (see Figure 5-6). 

Thus the curve, towards the axis of symmetry, cannot cease moving away from the axis of revolution and since it also cannot change the direction of its curvature, it must cut the axis of symmetry finally it is understood that consequently there is another condition which governs the curve it must cut this axis obliquely, so that we arrive at this conclusion, that it forms a node (fig. 41). 

The parallelization of crystallites, occurring as a result of fiber drawing, which consists in assuming by crystallite axes-positions more or less mutually parallel, leads to the development of texture within the fiber. In the case of PET fibers, this is a specific texture, different from that of other kinds of chemical fibers. It is called axial-tilted texture. The occurrence of such a texture is proved by the displacement of x-ray reflexes of paratropic lattice planes in relation to the equator of the texture dif-fractogram and by the deviation from the rectilinear arrangement of oblique diffraction planes. With the preservation of the principle of rotational symmetry, the inclination of all the crystallites axes in relation to the fiber axis is a characteristic of such a type of texture. The angle formed by the axes of particular crystallites (the translation direction of space lattice [c]) and the... 

Figure 16-16. Molecular packing of Oocl-OPV5 in the crystal lattice. Lett oblique view of (he unit cell of Oocl-OPV5 right projection of the unit cell on a plane perpendicular to the ci-axis.

Fig. 3.1.4 Anisotropic self-diffusion of water in and filled symbols, respectively). The horizon-MCM-41 as studied by PFG NMR. (a) Depen- tal lines indicate the limiting values for the axial dence of the parallel (filled rectangles) and (full lines) and radial (dotted lines) compo-perpendicular (circles) components of the axi- nents of the mean square displacements for symmetrical self-diffusion tensor on the inverse restricted diffusion in cylindrical rods of length temperature at an observation time of 10 ms. / and diameter d. The oblique lines, which are The dotted lines can be used as a visual guide, plotted for short observation times only, repre-The full line represents the self-diffusion sent the calculated time dependences of the...

It should be noted that equatorial or diequatorial conformers of substituted cyclohexanes could be accommodated in the thiourea canals by the stacking of guests at an oblique angle or parallel to the canal axis. X-ray structural data is so far unavailable... 

Monoclinic Three axes (denoted as a, b, and c) of unequal length intersect such that a and c lie at an oblique angle, and the b axis is perpendicular to the plane formed by the other two. 

One of the shortcomings of oblique-texture diffraction pattern is the formation of the dead zone around the texture axis and, thus, the absence of reflections located outside the interference field of the pattern. To reduce of dead zone, one has to obtain diffraction patterns as to maximum possible tilt angles of the texture axis to the beam (60-80°). 

If unit cell is orthogonal there are layers lines on oblique texture electron diffraction pattern. These lines occur when certain reciprocal lattice planes lie perpendicular to the texture axis. In this case period c may be more accurately determined by measuring the minor semi-axis R of any ellipse (in the presence of layer lines it is measured directly, since there is a zero line with /=0) and H of any reflection on that ellipse (preferably with a large l) ... 

Oblique texture patterns have almost perfect 2mm symmetry and thus the whole set of diffraction spots is represented by the reflections in one quadrant. The arcs are exactly symmetrically placed relative to the major axis, being sections of the same spherical band in reciprocal space. The reflections on the lower half of the pattern are sections of reciprocal lattice rings, which are Friedel partners and thus equivalent to those giving the reflections of the upper half assuming a flat surface of the Ewald sphere. Actually, if the curvature of the Ewald sphere is taken into account, the upper and lower parts of a texture pattern will differ slightly. 

Extinction calculations for obliquely incident light, also taken from Asano (1979), are shown in Fig. 11.16. The symmetry axis is parallel to the z axis and the direction of the incident beam, which makes an angle with the symmetry axis, lies in the xz plane, the plane of incidence. The incident light is polarized cither with its electric field or its magnetic field perpendicular to the plane of incidence these two polarization states are denoted by TE (transverse electric) and TM (transverse magnetic). 

Examine each external weld visually to ensure there are no surface defects, and record. Examine each interior weld and adjacent areas, both visually and by the use of a horoscope. Welds not accessible with the horoscope must be examined by y-ray with photo. 3 shot by weld two perpendicular to the tube axis (moved at 90°) and one oblique compared to the tube axis. 

The presence of phase transitions at 19 and 30°C provides an opportunity to test the proposed deformation model. Below 19°C the lattice contracts into a triclinic structure witli strong intermolecular interaction. 5,26 sjamplcs deformed below 19°C should develop off-c-axis orientation while samples deformed above 30°C should not. Figures 1.12 and 1.13 show inverse pole figures for samples deformed at 2 and 70°C. The observed orientation agrees with our proposed model. - With tlris set of experiments, it is possible to activate the oblique slip process or, alternatively, to deactivate it in the high-temperature phase above 30°C. 

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