Diffraction spectra, X-ray

For instance, in the three crystalline forms (a, 3, y) of i-PP the chains are always in the conformation of threefold helix (s(3/l)l symmetry) but are packed in different ways in monoclinic [24], hexagonal [25], and orthorhombic [26] unit cells, respectively. The X-ray diffraction spectra of unoriented samples in the crystalline forms a, P, y are reported in Fig. 6. 

Fig. 6 a-c. X-ray diffraction spectra (CuKa) of unoriented samples of a) a form b) y form c) p form containing only minor a form impurities [41]... 

Because 0-acyl chitins appear to be scarcely susceptible to lysozyme, the susceptibility of DBG to Upases has been studied to obtain insight into its biodegradability in vivo. The changes in infrared and X-ray diffraction spectra of the fibers support the slow degradation of DBG by Upases [125,126]. The chemical hydrolysis of DBG to chitin is the most recent way to produce regenerated chitin. 

Figure 3. X-Ray diffraction spectra of the natural aurichalcite mineral (a), mineral aurichalcite calcined at 350°C for 4 hours (b), and the sample in (b) recalcined at 400 C for 4 hours (c).

Samples with different loadings of rare earth and yttrium oxides on MS25 Si-Al were prepared and characterized. Figure 1 shows the x-ray diffraction spectra of a sample of 25% Nd203/Si-Al compared with the unmodified Si-Al. 

The chemical analyses of the samples are reported in Table 2. The X-ray diffraction spectra of these solids do not show the presence of any Cu oxide phase with size larger than 3-4 nm, excepted in the cases of Cu(3)Si02 and Cu(4)Zr02 on one side, Cu(146)Na(6)FAU-10 and Cu(146)Na(28)MFI-15 on the other side, where the lines characteristic of CuO do appear with a line broadening corresponding to a particle size of about 4 nm. 

Fig. 7.11 Effect of different experimental conditions on X-Ray diffraction spectra [46]. (a) Without orifice, 4% Ca(OH)2 slurry, 5 1/min C02 flow rate, (b) 1 mm orifice, 4% Ca(OH)2, slurry 5 1/min C02 flow rate, (c) 2 mm orifice 4% Ca(OH)2 slurry 5 1/min C02flow rate, (d) 3 mm orifice 4% Ca(OH)2 slurry 5 1/min C02 flow rate, (e) 4 mm orifice 4% Ca(OH)2 slurry 7 1/min C02 flow rate, (f) 4 mm orifice 2% Ca(OH)2 slurry 5 1/min C02 flow rate, (g) 4 mm orifice 6% Ca(OH)2 slurry, 5 1/min C02 flow rate, (h) 4 mm orifice 4% Ca(OH)2 slurry, 3 C021/min flow rate, (i) 4 mm orifice, 4% Ca(OH)2 slurry, 5 C02 1/min flow rate...

Interpretation of measurements of methods X-ray fluorescence spectrometry (Janssen and van Espen [1986] Arnold et al. [1994]), X-ray diffraction spectra (Adler et al. [1993]), NMR spectra (HIPS, Wehrens et al. [1993a]), HPLC retention indices (RIPS, Wehrens [1994]), Karl Fischer titration (HELGA, Wunsch and Gansen [1989]). 

Adler B, Schtitze P, Will J (1993) Expert system for interpretation of X-ray diffraction spectra. Anal China Acta 271 287... 

Table 5 Changes in the crystallite size of some polycyclic pigments in coatings or plastics coloration as a result of heat exposure (calculated from the X-ray diffraction spectra).

Linear trans-quinacridones exhibit multiple crystal modifications. This phenomenon is reflected in the different reflection angles which are observed in the X-ray diffraction spectra of the pigment powders. This effect may be exemplified by describing the polymorphous phases of unsubstituted quinacridone. 

The novel modifications were characterized by different X-ray diffraction spectra. So far, like the S-modification [20] they are of no commercial importance. 

Fig. 93 shows the reflection angles of the a-, (3-, and y-crystal modifications. The measurements were carried out on powder diagrams derived from X-ray diffraction spectra. 

A standard method for confirming coherence of the layers is the study of x-ray diffraction spectra. If the layers are coherent and there are enough of them to provide a relatively strong Bragg diffraction pattern, satelhtes due to superlattice (see Chapter 16) formation should appear on each side of the Bragg diffraction peak. Although detailed treatments can be found in the literature, we present below a simplified but rather useful formula for the determination of layer periodicity. 

Analytical. Infrared absorption and x-ray diffraction spectra are given in Ref 21... 

Fig. 8. X-ray diffraction spectra for MSW bottom ash treated 0.4 moles of PO4 /kg of ash. The four fractions were produced using the presence or absence of treatment and the use of the Dutch Total Availability leaching protocol (from Crannell et al. 2000).

Goes over (25%) to HMX on treatment with 98% nitric acid at 5°(Refs 3 4). X-ray diffraction spectra of SEX are given in Ref 2, UV absorption spectra in Refs 5 7 and analytical procedures in Ref 8... 

E.DeVries E.St.Clair GantzJACS 76,1009 (1954) CA 48,7995(1954) (Dissociation constants of l-methyl-l-amino-3-nitroguanidine) 3)L.A. Burkardt, AnaiChem 28,323(1956) CA 50,7540 (1956) (X-ray diffraction spectra of 1-amino-l-methyl-2-nitroguanidine) (This compd was apparently ptepd at the US NavQrd Test Sta,China Lake,... 

X-ray diffraction spectra of 5-amino-l-methyl-a-tetrazole axe discussed in Ref 6, its thermal isomerization in Ref 9, and its UV and IR absorption spectra In Ref 10... 

Natta, Porri, Carbonaro and Lugli (25) have prepared copolymers of 1,3-butadiene with 1,3-pentadiene in the whole range of compositions. The properties of the copolymers, in which all butadiene and pentadiene comonomer units are in the trans-1,4 configuration, clearly show the isomorphous replacement between the two types of units. The melting point/composition data show that the copolymer melting temperatures are a regular function of composition and are always comprised between those of trans-1,4-polybutadiene modification II and trans-1,4-polypentadiene. Also the X-ray diffraction spectra of the copolymers show that the trans-1,4-pentadiene units are isomorphous with the trans-1,4-butadiene units crystallized in the crystalline modification of the latter stable at high temperatures (form II). 

Central ite 1 Analytical Procedures. Centr 1 can be detected by various colorimetric tests, such as described in Refs 1,6,12,24, 28 Sc 33. Some other qualitative tests are given in Ref 13. Quantitative detns of Centr 1 by bromination methods are described in Refs 4,5,7,9,10,14,16,17,20,27,34 Sc 35. Chromatographic and spectrophotometric methods are found in Refs-11,15,18,21,22,23,24, 29,30,32 Sc 33. Other quantitative methods, including polarographic, are in Refs 2,7a,20a,25, 26,27 Sc 30. X-ray diffraction spectra data are given in Ref 19. Detns of stabilizing action of Centr 1 by methods of Taliani and Thomas are discussed in Refs 3 8... 

NG 43.00, DEtPh 3.00, K sulfate 1,25 EtCentr 0.60%] 19)A.M.Soldate R.M.Noyes, AnalChem 19, 442-4(1947)(X-ray diffraction spectra for Centr 1) 20)I.S.Hirschhom, AnalChem 19, 880-2(1947) [Rapid method of detn of Centr 1 NG in rocket propints. Both ingredients are extracted with 84% AcOH and then Centr is detd by bromination method of Waugh et al(See Ref 16)] 20a)T.C.J. 

Figure 15.2. X-ray diffraction spectra of the inside and outside portion of a 6 in x 12 in Portland cement cylinder partially reacted with supercritical C02. The solid circles identify the peaks due to Ca(OH)2, while the solid triangles show the diffraction peaks due to CaC03.

The X-ray diffraction spectra were recorded on a Philips PW-1130/90 apparatus using the copper Ka radiation (A = 1,5405 A). 

For both NH4,K-L and NH4, TMA-ft, the X-ray diffraction spectra (Figure Id, e) indicate that both zeolites retain most of their crystallinity after fluorine treatment and 500°C calcination. Except for some minor changes in peak intensity for fluorine-treated NH4,K-L, there is no evidence of peak intensity and position change as found for other treated zeolites. After 600°C calcination in air, a further loss of crystallinity is seen for fluorine-treated NH4,K-L. However, NH4,TMA-ft loses virtually all crystallinity. 

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