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Innovations for chemists: HA-100 NMR
The high-resolut ion HA-100 Spectrometer is recognized as the NMR standard in laboratories throughout the world. Its unmatched performance is now even better, with sensitivity increased to 40:1. With this new sensitivity, plus stability and resolving power, the HA-100 meets and exceeds rated specif ications year after year with only normal maintenance. This is another example of innovations in NMR, EPR, Mass Spectrometry, and Laboratory Magnets to help the chemist do a better job more easily. For information, contact your local Varian representative.
varian analytical instrument division palo al to/cal i fornia 94303 zug/Switzerland · Sydney/australia
Circle No. 180 on Readers' Service Card 8 0 A » ANALYTICAL CHEMISTRY
as micro (<20 A), intermediate (20-200 Â) and macro (>200 A) leading to distinct types of sorption, and the book is organized along these lines.
Chapter 2 includes a long discussion of the BET and other monolayer methods as applied to nonporous solids. Chapter 3 concerns surface area and pore size distribution from physical adsorption data on porous solids. The reader is left uncertain as to the best way to handle the hysteresis problem in calculation of pore size distribution.
Chapter 4 considers adsorption on microporous solids which is a timely and needed review in view of the current importance of molecular sieves. Chapter 5 deals with conversion of adsorption data to two dimensional equations of state by the Gibbs equation and interpretation from this point of view including a discussion of Ross and Olivier's work with this approach. Chapter 6 on chemisorption, although not comprehensive, should be useful to workers in the field of catalysis.
The text is concluded by a useful section on experimental methods, numerous figures and tables serve as documentation and improve understanding of the various relationships throughout.
The book is particularly recommended for workers in the adsorption field and should also be of value to those interested in determining surface properties of solids. I t provides an excellent, well organized, up to date review of British literature and limited reference to U. S. work.
In. general, it is similar to other reviews on the subject and does not appear as critical as the objective implies.
Typography is excellent and no significant errors were noted. Author indexing is rather hard to utilize.
The Formation and Properties of Precipitates. Alan G. Walton, xi + $32 pages. John Wiley & Sons, 605 Third Ave., New York, Ν. Y. 10016. 1967. $11.
Reviewed by Lester C. Howick, Department of Chemistry, University of Arkansas, Fayetteville, Ark. 72701.
In this book Professor Walton presents a readable and current introduction into the state of our knowledge concerning precipitate formation and properties. While providing a quantitative approach, he does not allow the presentation to become overly mathematical and constantly stresses the interpretation and meaning of the expressions as well as commenting upon the presence or absence of experimental support for their acceptance.
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