Space processing

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

Mercuric iodide crystals grown by physical vapor transport on Spacelab 3 exhibited sharp, weU-formed facets indicating good internal order (19). This was confirmed by y-ray rocking curves which were approximately one-third the width of the ground control sample. Both electron and hole mobiUty were significantly enhanced in the flight crystal. The experiment was repeated on IML-1 with similar results (20). 

Test of Dendritic Growth Models. The microgravity environment provides an excellent opportunity to carry out critical tests of 

Larson, Growth of CdZnTe Compound Semiconductors on Earth and in Space, in Ref. 7. 

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CARDIOVASCULARAGENTS](Vol5) piOSEPARATIONS] (Supplement) space [SPACE PROCESSING] (Vol 22)... 

Space optics Space probes Space processing... 

The abihty to remove heat from electrophoretic systems has severely limited the maximum capacity of these systems in terms of how large or thick the systems can be. Electrophoretic separations have been performed on space flights because the effect of gravity in outer space is small and mixing from heating is negligible. Whereas electrophoresis in outer space has been accompHshed (10), the economics for a scaleable process have not (see Space processing). 

Micro reaction systems may help to overcome or at least reduce some of the above-mentioned limitations [69]. Electrochemical micro reactors with miniature flow cells where electrodes approach to micrometer distances should have much improved field homogeneity. As a second result of confined space processing, the addition of a conducting salt may be substantially reduced. In addition, benefits from a uniform flow distribution and efficient heat transfer may be utilized. 

Solid versus grating floors within the enclosed space process structures... 

Some of the mathematical tools, such as the linear one-box model, are both fairly simple and nonetheless sufficient for handling a great variety of situations. More complex systems require the use of multibox models. In some cases, continuous time-space models are needed. The mathematics of the latter involve partial differential equations and quickly lead beyond the scope of this book. In this chapter, a few important concepts were discussed which allow the reader both to make some approximative calculations and to critically analyze the results from computer models in which time-space processes are employed. 

A. Establish the point kinetics and equilibrium isotherm for the adsorption step at the site, and the rate coefficients for the various space processes. These are the two types of data required for design. To some extent estimates may be made for the coefficients for the space processes. 

It is desirable to list the sequence of space and point steps which together constitute global adsorption. This is not a new concept and such descriptions have frequently been presented (I, 14), particularly for fluid reactions on porous catalyst particles. The first space process, axial dispersion, is not a part of the. sequence, but it does affect the observed kinetics, and is logically considered as a space process. Its significance depends upon the reciprocal of the axial Peclet number, EJ(2R)v. The sequential steps are ... 

The intent of this paper is to point out that physical or space processes, which usually influence and frequently control kinetics of adsorption in aqueous systems, can be represented effectively by quantitative models. The rate coefficients in such models are more meaningful than those associated with schemes which do not recognize space processes. Published reports have frequently analyzed data by a chemical model, but in such instances the reaction rate constants are found to... 

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