9780260900708 - Standard Reference Materials: Uranium Isotopic Standard Reference Materials (Certification of Uranium Isotopic Standard Reference Materials) (Classic Reprint) di Ga... (3 risultati)

PAP. Condizione: New. New Book. Shipped from UK. Established seller since 2000.

PAP. Condizione: New. New Book. Shipped from UK. Established seller since 2000.

Paperback. Condizione: New. Print on Demand. This book describes the work done by the Analytical Mass Spectrometry Section of the National Bureau of Standards on the development and characterization of standard reference materials for the isotopic composition of uranium. Many of the general rules and control measures necessary to make a meaningful comparison of ion currents are applicable to the analysis of other elements. Though the initial measurement of isotopic composition of the uranium standard reference materials was completed in 1959, a 5 year period of intensive evaluation and development of chemical procedures, mass spectrometric instrumentation, and mass spectrometric analytical procedures followed. The establishment of sound analytical procedures required evaluation of error contributions from chemistry, instrumentation, and mass spectrometric procedure. Through this work, the stoichiometry of U308 was investigated in hopes of finding an easily reproducible ignition procedure that would give stoichiometric U308. Some of the previous work indicated the rate of cooling could affect the ignition loss and there have been personal communications indicating slight changes in ignition loss at different geographic locations having different altitudes or atmospheric pressures. A series of thermogravimetric analysis ignitions were conducted varying the air pressure and oxygen content. Accurate cooling experiments could not be carried out conveniently with the equipment available. One gram samples of SRM 950a were ignited in a tube furnace to obtain ignition losses under different cooling procedures as well as under various temperatures and pressures. The results showed not only a significant increase in loss on ignition at increasing temperatures but increasing loss with faster cooling rates and indicated that a very slow cooling rate might give a reproducible ignition loss but that it would be nonstoichiometric to approximately the same extent as the ignition used for all samples in the isotopic program. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.