Moire fringes

Figure 4, Area of benzene covered gold (111). surface, for two different objective len.s defooi a.s required for unique image interpretation (see 2 ). Tri a) the gold atomic columns are black, in b) white. Moire fringes, rather than any true structural image, result from the benzene monolayer. Simulations (right) have benzene overlay on top surface only.

Figure 3.32 Measurement of liquid film thickness by Moire fringes (a) experimental setup and (ft) Moire pattern with liquid films of varying thicknesses. (From Kheshgi and Scriven, 1983. Copyright 1983 by Elsevier Science Ltd., Kidlington, UK. Reprinted with permission.)...

The moire of two cross sections of the hyperboloids represents the difference of two interference patterns. If the two cross sections are identical but one is displaced, the moire fringes also represent the loci of constant resolution in the displacement direction. If one focal point is fixed, and the other one is displaced, the resulting moire pattern forms a new set of hyperboloids whose foci are the two positions of the displaced focal point. This new pattern is independent of the position of the fixed focal point (a rotation of one of the original spherical wavefronts of Fig. 5 produces no moire effect). Therefore hologram interference fringes are independent of the position of the point source of the fixed reference beam. 

The principle of mechanical fixation at step edges is illustrated in Fig. 31 which shows Ru particles on a graphite surface. The single crystalline flake is preferentially (001) oriented but exhibits a system of step structures as revealed by the Moire fringes (weak line... 

Figure 6.5. Diffraction patterns for (a) parallel and (b) rotational one-dimensional moire fringes. OPi = gi OQ, = g2 OQ = 8 = g2-gi-...

Thus, one-dimensional parallel and rotational moire fringes can be clearly distinguished because they are always normal and parallel to g, respectively. Whether a one-dimensional or two-dimensional moire pattern is produced depends on the number of doubly diffracted beams that pass through the objective aperture. It is clear from Figure 6.5 that moire fringes will also be produced in dark-held images. 

Figure 8.38. Lattice-fringe image of a grain boundary in Oak Hall limestone-The boundary plane is inclined and gives rise to moire fringes.

Tholen, A. R. (1970). On the ambiguity between moire fringes and the electron diffraction contrast from closely spaced dislocations, phys. slat, sol., (a)2, 537-50. 

Scott JC, Stephens RWB (1972) Use of moire fringes in investigating surface wave propagation in monolayers of soluble polymers. J Acoust Soc America 52 871-878... 

Optical methods of spectrometer calibration include laser interferometric methods and Moire fringe counting techniques. Since such methods depend on the accurately known wavelength of light (for example, 6328.1983 A for a He-Ne laser at 293 K under standard conditions), they are independent of any assumptions made in the iron foil technique and, thus, are intrinsically more reliable. Moreover, such methods do not require the acquisition of57 Co Mdssbauer sources and reference materials for iron absorber studies and may thus be attractive... 

Clearly, if AEqo = 0, all the levels of the two series coincide and there are no Moire fringes. Also, if... 

An apparatus specifically designed for plastics has been described by Wright (. ]. This makes u.se of a moire fringe extensometer. which is essentially digital in operation and hence does not introduce any errors due to drift in sensitivity with time. Comparatively less sophisticated apparatus will be adequate for materials of lower stiffness and for shorter times of test. 

Mohs hardness See test, Mohs hardness, moire fringe analysis See test, nondestructive moire fringe-analysis. 

Strain analysis, moire fringe See test, nondestructive moire fringes analysis. 

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