BOOK REVIEWS Iodide Metals and Metal Iodides
Robert F . Rolsten, General Uynamirsl Convair, San Diego, California. John Wiley & Sons, Inc., New York, 1861. 441 pp. Figs. and tables. 15.5 xvi X 23.5 cm. $17.50. Many elemental metals have not yet been prepared in sufficiently high purity and in large enough quantities to permit definitive determination of their physical and mechanical properties. Since the invention of the "hot wire," or "iodide" method hy A. E. Van Arkel, about. 1823, and as a result of its important applications on the Manhattan Project during
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World War I1 and its subsequent industrial use, the number of metals remaining uncharacterized has rapidly dwindled. Much work, however, remains to be done, and for one who wishes to prepaTe a metal in a pure condition, this excellent book would provide a. good starting point. The periodic table, printed as Figure 1, shows that the method may be applied to all the metals from Group IIIB through Groups VA, inclusive, and not omitting the fourteen individual rare earth metals or the actinides. This hook reports the recent literature on each of them, indicating the extent to which success by the iodide method has been or may be expected to be achieved. Simply stated, the iodide process in-
volves the reaction of iodine with crude metal, evaporating the resulting iodide, and decomposing it on a "hot wire," frequently a heated tungsten filament. The iodine released is available to react further with the remaining crude metal to continue the process until all of the original supply has been transferred to the wire. The process may became considerably more complicated, requiring extended research to arrive a t satisfactory conditions, and for many of t,he metals for whieh it might be applicable, further work is indicated. The oxides, carbides, and nitrides, that usually account for the apparent brittleness of a metal, are left behind, and the metal collected is very much more ductile than the crude starting material. While it may be free from embribtling impurities, it is not necessarily free from other alloying metals. For example, ~irroniummay not he separated from hafnium by this technique. In recent years, the process has been important in the early phases of the commercial development of many metals, previously only laboratory curiosities. The inherent nature of the metal was revealed by measurements made on iodide-produced pure metal, which could also serve as the basis for alloy development. Titanium is the outstanding example of one that has become a structural material produced on a large scale, and ~ireonium,thorium, hafnium, and many ot,hers, have been developed commercially on a smaller scale in connection with the atomic energy program. While the ultimate commercial method may not involve the iodide process per se, the development phases depend on it far standard reference materials. The properties of ultra-pure beryllium and chromium are of special interest, particularly with reference to the question as to their inherent ductility or lack of it. Beryllium, the only metal discussed in Chapter 11 among Group IIA elements, has so far eluded preparation by the iodide method, and vhen made by other methods the metal has not been sufficiently pure to answer this question. Chromium, on the other hand, has been deposited at 1 0 W T from CrIa evaporated a t about. 800°C, with the result that the product could be reduced in thickness by as much as 40 per cent at room temperature, at a low strain rat,e. When given light blows from a hammer (high strain rate), on the other hand, the crystals fractured. Application of the technique to the production of alloys has not been successful, in general, but in some instances, metals that cannot he deposited alone by the iodide process (aluminum) can be deposited as alloys (Ti-AI; ZpAl). The book includes a bibliography of 739 referenres in which entries are listed serially, but not alphabetically by authors, which makes it somewhat difficult to consult. There is also a 10-page subject index that gives an adequately complete breakdown of topics, including all elements and compounds mentioned, but no authors names are included. Much of the good inorganic chemistry rtnd thermodynamics found in this book could he made t,he basis of research proj-
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BOOK REVIEWS ects for laboratory courses in inorganic chemistry. The technique is essentiall? simple and requires little unconventional apparatus, and much work remains to he done in the exciting field of preparing elements in the pure condition and investigating their properties.
LAURENCES. FOSTER Ordnance Materials Research Office Ti'ale~town,Massachusells Recent Advancer In Heat and Mass Transfer
Edited by J . P . Harlnelt and E. R. G. Eekert, both of the University of Minnesota, Minneapolis, H. S . Mickley, Massachusetts Institute of Technology, Csmhridge, and K. L. Pigford, University of Delaware, Newark. M e Graw-Hill Book Co., Inc., New York, 1961. viii 404 pp. Figs. and tables. 16.5 X 24 cm. $9.i5.
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"Recent Advances in Heat and Mass Transfer" was compiled to bring together under one cover a collertion of papers useful to practicing engineers and rosearchers. These papers --ere selected irom the technical literature and presumably represent t,he most significant contributions to the theory and practice of heat and mass transfer. Sixteen papem are included. About half of the work deals with some form of boundary layer theory as applied to problems of heat snd mass transfer with some consideration given to chemical reaction. I t is in the area, of boundary layer theory that the hook finds its strength. Also the turhulent transport mechanism in circular tubes is reasonably well covered with the inclusion of several excellent papers on this important and difficult subject. The coverage of other subject material is incomplete and certainly researchers inter~stedin aspects of heat and mass transfer other than the two mentioned above will find the collection incomplete and of little value. The sixteen articles all appear in readily accessible journals and with an exception, all were originally written in English. Thus with t,he advent of modern copying machines and the availability of reprint,^, it will he difficult to justify purchasing this book even though a numher of the articles selected are classics in their area.
R. S. SCHECHTER b'niversily of Tezas Austin Synthesis of Optimum Control Systems
Sheldon S. L. Chang, New York University, Xew Yark. McGraw-Hill Book Co., h e . , New York, 1961. xii 381 pp. Figs. and tables. 16 X 23.5 em. $11.75.
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Professor Chang's book deserves to be read by everyone seriously interested in automat~ccontrol, for it describes the most recent developments in the theory of optimal control. Many of these advances are the work oi the author him-
