High-energy point bars

Figure 2.7 Sedimentary facies in three general zones of the Ogeechee River/Ossabaw Sound estuary (USA). Fine-grained sediments predominate in the lower-energy region (stations 2, 3, and 4) as opposed to the high-energy point bars (station 5) and mouth (1) which have a higher abundance of coarse-grained sediments. (Modified from Howard et al., 1975.)...

Fig. 12. Demonstration of typical chemical shifts in lanthanide Lm absorption. The energy calibration of the spectra recorded from the Pr absorption in the compounds is accurate within 0.2 eV with respect to o fixed at the intersection point of the high-energy absorption with the absorption line in (dhcp) Pr metal (dashed-dotted line). The intersection point shifts to higher energies with decreasing metallic character of the compounds. The maxima of the prominent main lines, however, remain unshifted, just as the onsets of the lines. PrCu crystallizes in orthorhombic FeB structure (a = 7.343 A, 6 = 4.584 A, c = 5.604 A). The semi-metals PrSb, PrBi have fee (NaCl) structure a = 6.366 and 6.463 A, respectively). Pr Oi] is a nonstoichiometric modification of nominally tetravalent Pr02 (fluorite type, Cap2). The bar diagram indicates ligand-field-split absorption lines for both, the tri- and tetravalent valence states in Pr Oij (cf. section 14).

Concentration of waste sulfuric acid is extremely energy intensive due to the high heat of evaporation of water and the necessary supply of the heat of dehydration of sulfuric acid. Concentration processes in which the heat of evaporation is supplied indirectly are mainly carried out under reduced pressure. (The boiling point of 70% sulfuric acid is 160°C at 1 bar and 54°C at 0.01 bar.) Temperatures of 320°C are required at atmospheric pressure to concentrate up to 96% sulfuric acid. The highest concentration attainable by evaporation is 98.3% (azeotropic composition). 

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