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Crystal acceptable

Figure 7.6 (cont.) In (b) the toastrack arrangement of films is shown schematically. The closest film to the crystal accepts the whole pattern whereby the outer parts (high 6, long A) contain spots that are not too densely packed. The inner (low 6, short A) parts of the front film would not be quantified because of too high a density of spots. Instead these would penetrate to the rear films and expand to fill the available aperture but with a greatly reduced density of spots. From Helliwell (1991) with the permission of Elsevier. [Pg.291]

See also, I. C. Khoo, H. Li and Y. Liang, "Dynamics of Transient Probe Beam Amplifications via Coherent Multiwave Mixing in a Local Nonlinear Medium Nematic Liquid Crystal," accepted for publication in J. Quant. Electron December issue (1993). [Pg.138]

Tectosilicates and feldspars If in the tridimensional framework corresponding to the stoichiometric formula SiO (e.g., tridymite or cristobalite) a certain proportion of silicium atoms is substituted by aluminum atoms, in order for the lattice to preserve its structure, it is necessary that the crystal acquire one supplementary electron per aluminum atom. In order to restore the electroneutrality, the crystals accept ions, e.g., Na, which penetrate the holes of the lattice and become linked to the oxygen atoms. [Pg.29]

How much does the amount of heat required differ for heating a nanoparticle consisting of N atoms from temperature Tj = 0 K to T2 = 0 /50, compared to the amount of heat required to heat the same amount of particles in the form of a bulk crystal. Accept the nanoparticle s size L = 10a, a being the period of the crystal lattice 0 is the Debye temperature). [Pg.558]

A somewhat subtle point of difficulty is the following. Adsorption isotherms are quite often entirely reversible in that adsorption and desorption curves are identical. On the other hand, the solid will not generally be an equilibrium crystal and, in fact, will often have quite a heterogeneous surface. The quantities ys and ysv are therefore not very well defined as separate quantities. It seems preferable to regard t, which is well defined in the case of reversible adsorption, as simply the change in interfacial free energy and to leave its further identification to treatments accepted as modelistic. [Pg.352]

Boron trioxide is not particularly soluble in water but it slowly dissolves to form both dioxo(HB02)(meta) and trioxo(H3B03) (ortho) boric acids. It is a dimorphous oxide and exists as either a glassy or a crystalline solid. Boron trioxide is an acidic oxide and combines with metal oxides and hydroxides to form borates, some of which have characteristic colours—a fact utilised in analysis as the "borax bead test , cf alumina p. 150. Boric acid. H3BO3. properly called trioxoboric acid, may be prepared by adding excess hydrochloric or sulphuric acid to a hot saturated solution of borax, sodium heptaoxotetraborate, Na2B407, when the only moderately soluble boric acid separates as white flaky crystals on cooling. Boric acid is a very weak monobasic acid it is, in fact, a Lewis acid since its acidity is due to an initial acceptance of a lone pair of electrons from water rather than direct proton donation as in the case of Lowry-Bronsted acids, i.e. [Pg.148]

The deterrnination of the stmcture of Fe (00) 2 proved to be a difficult problem. An early report on the crystal stmcture claimed the molecule was a monoclinic prism and estabHshed the molecular formula (22). In a later report stmcture (8) was shown to be a triangular array of iron atoms with two bridging and 10 terminal CO molecules. This accepted stmcture was initially deduced from an x-ray crystal stmcture of the Fe2(CO)22H analogue (23). [Pg.64]

Solidification. Production of a product in a form suitable for use and acceptable to the consumer also may be an objective of a crystallization process. For example, the appearance of sucrose (sugar) varies with local customs, and deviations from that custom could lead to an unacceptable product. A final crystallization may thus be called for to bring the product appearance into compliance with expectations. [Pg.338]

Thermally efficient calcination of lime dolomite and clay can be carried out in a multicompartmeut fluidized bed (Fig. 17-27). Fuels are burned in a fluidized bed of the product to produce the required heat. Bunker C oil, natural gas, and coal are used in commercial units. Temperature control is accurate enough to permit production of hme of very high availability with close control of slaking characteristics. Also, half calcination or dolomite is an accepted practice. The requirement of large crystal size for the hmestoue limits apphcatiou. SmaU-sized crystals in the hmestoue result in low yields due to high dust losses. [Pg.1573]


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Acceptable crystal structures

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