Secondary crystallization crystal thinning

Figure 3.22. Schematic presentation illustrating the secondary crystallization process (thin lines crystallizable component, thick lines amorphous component).

Iron redistribution in InP(Fe) annealed without an encapsulant was studied by using secondary ion mass spectrometry. In annealed crystals, thin surface Fe accumulation followed by Fe depletion occurred. It was clearly shown that the Fe redistribution resulted from thermally stimulated Fe out-diffiision described by ... 

Isothermally crystallized PECT copolymers containing low amounts of 1,4-CHDM units present a triple melting behavior (81,82).The lowest temperature peak was attributed to melting of very thin and defective crystals formed in the last crystallization stages whereas the highest temperature one was associated to crystals generated by primary crystallization. The intermediate endo-therm was interpreted to arise from both secondary crystals and defective primary crystals. 

The product has purities typically in the 90—92% range and can be combined with thin juice, concentrated and crystallized, or concentrated and stored for later use. Crystallizing the desugarization thick juice apart from the normal beet campaign may be desired because the secondary molasses produced after the separation contains the nonsucrose components, which are the most difficult to separate from sucrose and perhaps should be set aside and sold instead of resubmitted to the columns. 

We have undertaken a series of experiments Involving thin film models of such powdered transition metal catalysts (13,14). In this paper we present a brief review of the results we have obtained to date Involving platinum and rhodium deposited on thin films of tltanla, the latter prepared by oxidation of a tltanliua single crystal. These systems are prepared and characterized under well-controlled conditions. We have used thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES) and static secondary Ion mass spectrometry (SSIMS). Our results Illustrate the power of SSIMS In understanding the processes that take place during thermal treatment of these thin films. Thermal desorption spectroscopy Is used to characterize the adsorption and desorption of small molecules, In particular, carbon monoxide. AES confirms the SSIMS results and was used to verify the surface cleanliness of the films as they were prepared. 

Thin-film electrodes have promise in the development of flexible power sources (primary and secondary). It must be taken into account that change in cathodic material crystal lattice must not be over 20% as a result of intercalation of Li+, Na+ or FT [4], The electrodes must be chemically active and have both electron and ion conductivity. In connection with these... 

Zeolite membranes are generally synthesized as a thin, continuous film about 2-20 xm thick on either metallic or ceramic porous supports (e.g., alumina, zirco-nia, quartz, siHcon, stainless steel) to enhance their mechanical strength. Typical supported membrane synthesis follows one of two common growth methods (i) in situ crystallization or (ii) secondary growth. Figure 10.2 shows the general experimental procedure for both approaches. 

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