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XVII-15. Characteristic isotherm for nitrogen at 78 K on various solids

XVII-17. Schematic phase diagram for O2 on graphite

XVII-18. Contours of constant adsorption energy for a krypton atom over the basal plane of graphite. The carbon atoms are at the centers of the dotted triangular regions. The rhombuses show the unit cells for the graphite lattice and for the commensurate adatom lattice.

XVII-20. Isosteric heat of adsorption of Xe on a stepped Pd surface 8

XVII-21. Continued

XVII-22. Isosteric heats of adsorption for Kr on graphitized carbon black. Solid line


XVII-25. Interaction energy distributions for N2 on BN

XVII-26. The arrangement of

XVII-27. Nitrogen adsorption at 77 K for a series of M41S materials. Average pore diameters

XVII-28. Hysteresis loops in adsorption.

XVII-29. Nitrogen isotherms the volume adsorbed is plotted on an arbitrary scale. The upper scale shows pore radii corresponding to various relative pressures. Samples

XVII-3. Langmuir isotherms.

XVII-30. Adsorption of Na on a silica gel at 77.3 K, expressed as a u- plot, illustrating a method for micropore analysis.

XVII-31. Copyright 1987, American Chemical Society.

XVII-4. Langmuir plus lateral interaction isotherms.

XVII-5. Schematic detector response in a determination of nitrogen adsorption and desorption. A flow of He and N2 is passed through the sample until the detector reading is constant the sample is then cooled in a liquid nitrogen bath. For desorption, the bath is removed.

XVII-7. Brunauer s five types of adsorption isotherms.

XVIII-11. Calorimetric differential heat of adsorption of H2 on ZnO. Dashed line

XVIII-13. Activation energies of adsorption and desorption and heat of chemisorption for nitrogen on a single promoted, intensively reduced iron catalyst Q is calculated from Q Edes - ads-

XVIII-14. Schematic illustration of the movement of NO molecules on a Pt. Copyright 1985, American Chemical Society.

XVIII-15. Oxygen atom diffusion on a W surface

XVIII-16 sketches what can happen in the case of a metal surface . In Fig. XVIII-16 2 two atoms or molecular entities each with a frontier orbital having two electrons potentially can interact to give bonding and antibonding levels, as shown in the middle however, since both levels are filled, there is no net bonding. The same atom or molecular entity can bond to a metal surface if the antibonding level is above the Fermi level of the metal, so that the antibonding electrons dump into the sea of metal electrons. Alternatively, one unfilled orbital each from the atoms or molecular entities can hypothetically form bonding and antibonding orbitals, both now empty, as shown in Fig. XVIII-16c. If, now, the bonding level lies below the Fermi level, electron transfer can occur, resulting in bonding as shown in Fig. XVIII-16d.

XVIII-16. A four-electron two-orbital interaction that a has no net bonding in the free molecule but can be bonding to a metal surface if

XVIII-17. Correlation of catalytic activity toward ethylene dehydrogenation and percent d character of the metallic bond in the metal catalyst.

XVIII-18. Interaction of the a and n molecular orbitals with the Pt d band Ef is the Fermi level.

XVIII-19. Band bending with a negative charge on the surface states

XVIII-2 shows how a surface reaction may be followed by STM, in this case the reaction on a Ni surface

XVIII-20. Spectra of pyridine adsorbed on a water-containing molybdenum oxide -Al203 catalyst

XVIII-21. The framework structure of faujasite.

XVIII-22. Schematic illustration of the steps that may be involved in a surface-mediated reaction

XVIII-23. Potential energy diagram for jN2 jH2 NH3.

XVIII-25. The ethylidyne mechanism for ethylene hydrogenation.

XVIII-26. A well-ordered pillared clay with almost exclusively zeolitelike microporosity.

XVIII-27. Specific rates of CO oxidation on single crystal and supported catalysts as a function of temperature.


XVll-19. Adsorption of CH4 on MgO

XVn-11. The van der Waals equation of state isotherm.

XVn-14. Adsorption of nitrogen on potassium chloride at 79 K, plotted according to various equations.

XVn-16. Infrared absorption spectra of H2 physisorbed on NaCl

XVn-24. Site energy distribution for nitrogen adsorbed on Silica SB.

Xylenes separation via Mitsubishi Gas—Chemical Co. HF-BF extraction—isomerization process . A extractor B decomposer C separator D isomerization reactor E heavy ends tower F raffinate tower G separator H light ends fractionator

Y value for the crack. Dimensions in mm.

Y-module positioned for set-up 2, for inspection of bonded areas on the leading edge.

Y-module positioned for set-up 3, for inspection of bonded areas on the trailing edge

Yarn strength vs twist level .

Yaws short-cut method compared to plate-to-plate calculations. Used by permission, Yaws, C. L. et al. Hydrocarbon Processing, V. 58, No. 2 p. 99. Gulf Publishing Co., all rights reserved.

Yellowness index vs two-roU mill heat stabiUty, where the mercaptide ligands, — SCH2COOR IT 9, and 6 Sn, respectively. R CgH. R H33.

Yield pressure of multicomponent vessels designed for optimum conditions .

Yield strength histogram for SAE 1018 cold drawn carbon steel bar

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