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Specific Sequestering Agents for the Actinides

Description: This paper summarizes the current status of a continuing project directed toward the synthesis and characterization of chelating agents which are specific for actinide ions - especially Pu(IV) - using a biomimetic approach that relies on the observation that Pu(IV) and Fe(III) has marked similarities that include their biological transport and distribution in mammals. Since the naturally-occurring Fe(III) sequestering agents produced by microbes commonly contain hydroxamate and catecholate functional groups, these groups should complex the actinides very strongly and macrocyclic ligands incorporating these moieties are being prepared. We have reported the isolation and structure analysis of an isostructural series of tetrakis(catecholato) complexes with the general stoichiometry Na{sub 4}[M(C{sub 6}H{sub 4}O{sub 2}){sub 4}] • 21 H{sub 2}O (M = Th, U, Ce, Hf). These complexes are structural archetypes for the cavity that must be formed if an actinide-specific sequestering agent is to conform ideally to the coordination requirements of the central metal ion. The [M(cat){sub 4}]{sup 4-} complexes have the D{sub 2d} symmetry of the trigonal-faced dodecahedron.. The complexes Th [R'C(0)N(O)R]{sub 4} have been prepared where R = isopropyl and R' = t-butyl or neopentyl. The neopentyl derivative is also relatively close to an idealized D{sub 2d} dodecahedron, while the sterically more hindered t-butyl compound is distorted toward a cubic geometry. The synthesis of a series of 2, 3-dihydroxy-benzoyl amide derivatives of linear and cyclic tetraaza- and diazaalkanes is reported. Sulfonation of these compounds improves the metal complexation and in vivo removal of plutonium from test animals. These results substantially exceed the capabilities of compounds presently used for the therapeutic treatment of actinide contamination.
Date: September 1, 1979
Creator: Raymond, Kenneth N.; Smith, William L.; Weitl, Frederick L.; Durbin, Patricia W.; Jones, E.Sarah; Abu-Dari, Kamal et al.
Partner: UNT Libraries Government Documents Department


Description: A total burn-spectrographic method has been applied to the determination of trace concentrations of silicon in plutonium. The sample is oxidized to plutonium dioxide, mixed with a germanium dioxide-graphite mixture containing tin internal standard, packed into cupped graphite electrodes, and burned to completion in a high amperage direct current arc. Plutonium spectral interference is minimized by optical means and by use of a less intense silicon line. The sensitivity is thereby decreased but is still sufficient to determine 25 ppm of silicon in plutonium. The precision of the method is estimated to be �8% (relative standard deviation) at the 270 ppm level and �14% at 40 ppm.
Date: July 1, 1965
Creator: Ko, Roy
Partner: UNT Libraries Government Documents Department


Description: The overarching objective of this conference is to catalyze the interchange of new ideas and recent discoveries within the basic radiation sciences of physics, chemistry, and biology, and to facilitate translating this knowledge to applications in medicine and industry. The 9 topics for the GRC are: "œFrom Energy Absorption to Disease", "œBiodosimetry after a Radiological Incident," "œTrack Structure and Low Energy Electrons," "Free Radical Processes in DNA and Proteins," "Irradiated Polymers for Industrial/ Medical Applications," "Space Radiation Chemistry/Biology," "Nuclear Power and Waste Management," "Nanoparticles and Surface Interfaces", and the "Young Investigator" session.
Date: August 3, 2012
Creator: LaVerne, y
Partner: UNT Libraries Government Documents Department


Description: A heavy-particle track model suggested by considerations presented in a companion paper is used in a calculation of the differential (G') and integral (G) yields of the Fricke dosimeter system for six selected particles over a wide range of energies. The particles are H, He, C, Ne, Ar, and Fm; the energy range for the first two is 10{sup -3} MeV/n to 10{sup 3} MeV/n, and for the last four is 10{sup -1} MeV/n to 10{sup 3} MeV/n. The calculated G' and G values are compared with experimental values as far as possible, and the heavy-particle track model situation is discussed.
Date: March 1, 1980
Creator: Chatterjee, Aloke & Magee, John L.
Partner: UNT Libraries Government Documents Department

Rapid Automated Dissolution and Analysis Techniques for Radionuclides in Recycle Process Streams

Description: The analysis of process samples for radionuclide content is an important part of current procedures for material balance and accountancy in the different process streams of a recycling plant. The destructive sample analysis techniques currently available necessitate a significant amount of time. It is therefore desirable to develop new sample analysis procedures that allow for a quick turnaround time and increased sample throughput with a minimum of deviation between samples. In particular new capabilities for rapid sample dissolution and radiochemical separation are required. Most of the radioanalytical techniques currently employed for sample analysis are based on manual laboratory procedures. Such procedures are time and labor intensive and not well suited for situations in which a rapid sample analysis is requires and/or large number of samples needed to be analyzed.
Date: July 18, 2013
Creator: Sudowe, Ralf
Partner: UNT Libraries Government Documents Department

Fate of Electrons with Energies Less Than 100 eV

Description: An introduction is given to some of the major processes which take place when low energy electrons collide with molecules. Temporary negative ion states, dissociative electron attachment, and vibrational and rotational excitation are emphasized. Resonances and some comments on H{sub 2}O are also covered. 45 refs.
Date: May 1, 1979
Creator: Stockdale, J. A. D.
Partner: UNT Libraries Government Documents Department

Improvement in the Plutonium Parameter Files of the FRAM Isotopic Analysis Code

Description: The isotopic analysis code Fixed-energy Response-function Analysis with Multiple efficiency (FRAM) employs user-editable parameter sets to analyze a broad range of sample types. This report presents new parameter files, based upon a new set of plutonium branding ratios, which give more accurate isotope results than the current parameter files that use FRAM.
Date: September 1, 2000
Creator: Vo, D. T. & Sampson, T. E.
Partner: UNT Libraries Government Documents Department


Description: Nuclear reactions induced by 7.6-MeV deuterons are used to determine total carbon in atmospheric aerosols. The {sup 12}C(d,n){sup 13}N reaction produces the radionuclide {sup 13}N, a 10.0-min positron emitter, which is detected by its 0.511-MeV annihilation radiation. The detection system is a Ge(Li) {gamma}-ray spectrometer. The method is nondestructive of the sample, permitting the sample to be studied by additional methods. Comparison of carbon found by deuteron activation analysis with that found by independent but destructive combustion methods shows a standard deviation of 10% for 15 samples analyzed over a wide range of carbon contents. The detection limit is estimated to be 0.5 {micro}g/cm{sup 2}, corresponding to a carbon concentration of 0.2% in a sample of total thickness 250 {micro}g/cm{sup 2}.
Date: December 1, 1979
Creator: Clemenson, Mark; Novakov, Tihomir & Markowitz, Samuel S.
Partner: UNT Libraries Government Documents Department

Alternative Bench Standards: Sample Production Report

Description: The INL has prepared four standards representing krypton concentrations of 1.1X, 1.54X, 10X and 100X the reported atmospheric value of 70 dpm 85Kr per cubic centimeter of Kr gas at 25 degrees C (ie. 1.1X is 1.1 x 70, or 77 dpm 85Kr per cubic centimeter of Kr gas at 25 degrees C). A t-zero date and time of January 1, 2012 at 1200 Zulu was used for all standards. The Alternative Bench Standards (ABS) of 1.1X, 1.54X, 10X and 100X, are designated by titles of ABS-A, ABS-B, ABS C and ABS-D, respectively. The concentration of Kr in air is 1.14 ppm.
Date: September 1, 2012
Creator: Mann, N. R.; Houghton, T. P.; Watrous, M. G.; Eisenmenger, J. G. & Hague, R. K.
Partner: UNT Libraries Government Documents Department