New Chemicals For a complete list of Standard Ref erence Materials available from NBS, see NBS Misc. Publ. 260 (1968 ed.) for sale by the Superintendent of Docu ments, U.S. Gov't Printing Office, Washington, D.C. 20402, for 45 cents. Phosphorus-32 Labeled Nucleics Soluble ribonucleic acid, P-32, is now available for use in sequence determina tions by Sanger's fingerprinting meth od. The product contains degraded ribosomal RNA and a mixture of transfer RNAs. It is obtained by phenol/water extraction of E. coli cells grown on a medium containing inorganic phos phate—P-32 and is purified by further partition between phenol and water, and then by ethanol precipitation. Ra diochemical yield is about 10%. The material is made to order and supplied as a freeze-dried solid in sealed glass ampoules, in refrigerated containers. The Radiochemical Centre, Amersham, Buckinghamshire, England. 501 Standards for Low-Alloy Steel Analysis Two new sets of standards, ideal for metals analysis via direct-reader instru mentation, are produced by the British Bureau of Analyzed Samples, Ltd., and supplied by Jarrell-Ash in the form of disks, 1-1/2 in. in diameter, 3/4 in. thick. Set One includes low-alloy steels Nos. 401 through 405; Set Two com prises Nos. 406 through 410. Each standard bears determinations for C, Cr, Cu, Mn, Mo, Ni, Ρ, Si, S, and V. Fisher Scientific Co., J308 Fisher Bldg., Pittsburgh, Pa. 15219 502
POWDER DIFFRACTION FILE , , . World's largest compilation of diffraction data available as• DIFFRACTION DATA CARDS • COMPUTER TIME SHARING • MAGNETIC TAPE • MICROFICHE • INDEXES • BOOKS
High-Purity Isotopes For the first time, the Atomic Energy Commission is making available highpurity concentrations of thorium, ura nium, and plutonium isotopes produced by the electromagnetic process at AEC's Oak Ridge National Laboratory and produced by radioactive disintegra tion processes at AEC's Mound Labora tory. Three isotopes of particular interest for various applications are uranium233, uranium-234, and plutonium-242. 233 U and 2 4 2 Pu are needed as tracers for radiometric and mass spectrometric measurements and analyses of yields and as alpha standards for instrument calibration. Only milligram quantities are needed for these purposes. Requests to purchase quantities of 233-rj, 234TJ, 2 4 2 P U ;
a n d
o t h e r
h i g h
p u r
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ity isotopes U, Th, and Pu should be sent to : Isotope Sales, Oak Ridge Na tional Laboratory, P.O. Box X, Oak Ridge, Tenn. 37830. 503
Compiled by the
JOINT COMMITTEE ON POWDER DIFFRACTION STANDARDS American Society for Testing and Materials American Crystallographic Association National Association of Corrosion Engineers Institute of Physics (British) For detailed information write:
DIFFRACTION DATA DEPT. A . S . T . M . HEADQUARTERS 1916 Race Street, Philadelphia, Pa.19103 Circle No. 90 on Readers' Service Card
VOL. 41, NO. 11, SEPTEMBER 1969 ·
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