X-ray diffraction patterns, for

Fig. 1. Structures of (O) atoms and corresponding electron and x-ray diffraction patterns for (a) a periodic arrangement exhibiting translational symmetry where the bright dots and sharp peaks prove the periodic symmetry of the atoms by satisfying the Bragg condition, and (b) in a metallic glass where the atoms are nonperiodic and have no translational symmetry. The result of this stmcture is that the diffraction is diffuse.

Fig. 9. Powder X-ray diffraction pattern for the (002) peak of CRO pitch samples as indicated. The data sets have been offset sequentially by 0, 500, 2000, 4400 and 5400 counts for clarity...

Fig. 6. X-ray diffraction pattern for corn cob xylan (Unpublished data).

Fig. 4.10 Powder X-ray diffraction patterns for samples of phase-pure Prl2-IV annealed at different temperatures.

Crystalline samples of syndiotactic poly(methyl methacrylate) (st-PMMA) may be obtained from chloroacetone 178). This guest could be completely replaced by a variety of other guest molecules such as acetone, 1,3-dichloroacetone, bromoacetone, pinacolone, cyclohexanone, acetophenone and benzene. The X-ray diffraction patterns for these inclusion compounds were similar. These data indicate that the st-PMMA chains adopt a helical conformation of radius about 8 A and pitch 8.85 A. The guest molecules are located both inside the helical canals and in interhelix interstitial sites. 

The x-ray diffraction patterns for MTF, PTF, and BTF are given in Figure 2. The unsymmetrical BTF shows broad dispersed peaks indicating an increase in amorphousness compared to MTF, its symmetrical analogue. The peaks in the pattern for PTF, on the other hand, are broader and less sharp than those for MTF, which may be the result of an increase in the alkyl chain length by two carbon atoms. 

Figure 17. X-ray diffraction patterns for high trans-SBi (15% styrene, 85%...

A room temperature powder X-ray diffraction pattern for Na8[GaSi04]6(C104)2 Sodalite with Si as an internal standard for phase identification in the reaction products has been studied. X-ray powder diffraction study confirms the cubic structure of Na8[GaSi04]6(C104)2 sodalite synthesized... 

The crystalline complex of PIB with either / or y-CD was insoluble even in boiling water, but it was solubilized when urea was added to the suspension and heated. This fact demonstrates the important role played by hydrogen bonding played in stabilizing the complex. The X-ray diffraction pattern for the complex of PIB with y-CD was entirely different from that for uncomplexed y-CD and suggested an extended column structure. 

The rate constants and interlayer distances determined from X-ray diffraction patterns for the intercalation studies described above are given in Table V. In those systems where intercalation causes large changes in the interfacial potential (ZrP and TiS2), Equations 32 and 33 were modified using intrinsic rate constants. In cases where steady state reactive intermediates were postulated, the rate constants in Equations 32 and 33 were modified as shown in Table V. 

The negative value of U in the fit in Fig. 7.11 signifies that the interaction between Li ions is attractive. Under an attractive interaction the ions can cluster, and the compound should separate into two phases at low temperatures. Fig. 7.12 shows one of the Bragg peaks in the X-ray diffraction pattern for Lio.sMoeScg as it cools (Dahn and McKinnon,... 

Figs. 1(a) and 1(b) show the best fits between calculated (solid line) and observed (dotted line) X-ray diffraction patterns for samples S3 and S4. 

Unfortunately, the X-ray diffraction patterns for different UZM-5 preparations showed broad peaks (due to the very small crystalhte size and anisotropic morphology) and were not of sufficient quality for ah initio structure solution. However, indexing the patterns did provide the crystal system (tetragonal) and approximate... 

Figure 4. X-Ray diffraction patterns for phosphorous-vanadium oxide catalysts prepared by aerosol technique at 600 C, 8 seconds residence time, and 0.8 M V in feed a. Catalyst analyzed by XRD immediately after synthesis, b. catalyst calcined at 450°C in nitrogen for 3 hrs immediately after synthesis, c. Catalyst allowed to stand for 14 days in an air tight container at ambient temperature without calcining.

Figure 7 X-Ray diffraction pattern for the aerosol synthesis of the calcium substituted perovskite Lao.8Cao.2 03 at 1200°C using a 3 seconds residence time.

This material may be removed by reheating the sample to 850°, followed by the same annealing procedure outlined above. The X-ray diffraction pattern for 2H(a)-TaS2 may be used for identification. The following d values have been obtained for major low angle X-ray diffraction lines (and intensities) 6.05 (1) 3.025 (0.06) 2.8709 (0.32) 2.7933 (0.07) 2.3937 (0.80) and 2.3389 (0.04) A. Note that it is difficult to obtain the ideal intensities because of preferred orientation of the crystallites. This material is a superconducting metal with Te = 0.8 0.05°K.2... 

Elements in the modern periodic table are arranged sequentially by atomic number in rows and columns. Mendeleev and his contemporaries arranged elements according to atomic mass. In 1913, Henry Moseley s (1887-1915) studies on the x-ray diffraction patterns for metals showed a relationship between the spectral lines and the atom s nuclear charge. Moseley s work established the concept of atomic number, the number of protons in the nucleus, as the key for determining an element s position in the periodic table. Rows in the periodic table... 

The tetroses (four-carbon sugars) have not yet been studied crystal-lographically, undoubtedly due to the lack of suitable crystals. Handbooks list D- or L-erythrose as a colorless syrup, and D- or L-threose as very hygroscopic, colorless, microscopic needles. The X-ray diffraction patterns for erythritol13 and for several derivatives of D- or L-tartaric acid have been solved. 

Figure 1.27 X-Ray diffraction pattern for tnngsten. Adapted from A. G. Gny, and J. J. Hren, Elements of Physical Metallurgy, p. 208, 3rd ed. Copyright 1974 by Addison-Wesley.

As with ceramics and metals, polymer crystals can have multiple crystal forms. Polyethylene has a metastable monoclinic form and a orthohexagonal high pressure form. A list of some of the more common polymers and their corresponding crystal strnctnres is given in Table 1.24. Finally, X-ray diffraction can be used to determine the amorphous to crystalline ratio in semicrystalUne polymers in much the same way that Eq. (1.61) can be used. Figure 1.66 shows a schematic illustration of the X-ray diffraction patterns for semicrystalline and amorphous polyethylene. The estimation of crystalline content is based upon a ratio of the peak areas in the two samples. 

CA 41, 6105(1947) (X-ray diffraction patterns for the identification of crystalline constituents of explosives) (Includes GuPicr)... 

FIGURE 2.8 X-ray diffraction pattern for the preparation of zircon, ZrSi04, from zirconia, ZrOz, silica, Si02, and sodium halide mineralisers. The peaks demonstrate zircon to be the main product containing traces of all the starting materials. 

X-Ray diffraction patterns for the galactomannans from guar, locust-bean, and tara gums show, with relative humidity, continuous variation of only the a dimension of the base plane. For guar gum, the a axis varies from 1.35 nm at 0% r.h. to 3.32 nm at 78% r.h., whereas, for lo-... 

X-ray diffraction patterns for different carbon/fluorine ratios demonstrate that the diffractions due to the starting materials disappear and are replaced by new diffractions.12 As shown in Table 2,12 the interlayer spacing of graphite and carbon black increases from 3.37 to 6.06 and 6.7 A. This increase is due to the electrostatic repulsion resulting from the fluorine atoms which have formed a layer above and below the carbon atoms. 

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