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Americium and plutonium in water, biota, and sediment from the central Oregon coast

Description: Plutonium-239, 240 and americium-241 were measured in the mussel Mytilus californianus from the region of Coos Bay, OR. The flesh of this species has a plutonium concentration of about 90 fCi/kg, and an Am-241/Pu-239, 240 ratio that is high relative to mixed fallout, ranging between two and three. Transuranic concentrations in sediment, unfiltered water, and filterable particulates were also measured; none of these materials has an Am/Pu ratio as greatly elevated as the mussels, and there is no… more
Date: June 1, 1982
Creator: Nielsen, R. D.
Partner: UNT Libraries Government Documents Department
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Electromigration of hydrogen and deuterium in vanadium, niobium, and tantalum

Description: The electric mobility and effective valence of hydrogen and deuterium in vanadium, niobium, tantalum and three niobium-tantalum alloys were measured. A resistance technique was used to directly determine the electric mobility of hydrogen and deuterium at 30/sup 0/C while a steady-state method was used to measure the effective valence. The use of mass spectrographic techniques on a single specimen which contained both hydrogen and deuterium greatly increased the precision with which the isotope … more
Date: October 1, 1977
Creator: Jensen, C. L.
Partner: UNT Libraries Government Documents Department
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Heated uranium tetrafluoride target system to release non-rare gas fission products for the TRISTAN isotope separator. [As replacement for uranyl stearate]

Description: Off-line experiments indicated that fluorides of As, Se, Br, Kr, Zr, Nb, Mo, Tc, Ru, Sb, Te, I and Xe could be volatilized, but except for Br, Kr, I and Xe, none of these elements were observed after mass separation in the on-line experiments. The results of the on-line experiments indicated a very low level of hydride contamination at ambient temperature and consequently, uranium tetrafluoride replaced uranyl stearate as the primary gaseous fission product target. Possible reasons for the fail… more
Date: October 1, 1977
Creator: Gill, R. L.
Partner: UNT Libraries Government Documents Department
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Effect of nuclear spin on chemical reactions and internal molecular rotation

Description: Part I of this dissertation is a study of the magnetic isotope effect, and results are presented for the separation of /sup 13/C and /sup 12/C isotopes. Two models are included in the theoretical treatment of the effect. In the first model the spin states evolve quantum mechanically, and geminate recombination is calculated by numerically integrating the collision probability times the probability the radical pair is in a singlet state. In the second model the intersystem crossing is treated vi… more
Date: December 1, 1980
Creator: Sterna, L.L.
Partner: UNT Libraries Government Documents Department
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Observation by flow sup 1 H NMR and dimerization kinetics and products of reactive ortho-quinodimethanes and benzocyclobutadiene

Description: The reactive o-quinodimethanes, 1,2-dimethylene-1,2-dihydronaphthalene (9) and o-xylylene (1) were observed by flow {sup 1}H NMR spectroscopy at room temperature. The {sup 1}H NMR spectrum of 9 was obtained in the absence of precursor and dimers. However, the {sup 1}H NMR spectrum of the more reactive 1, generated in a similar manner from (o-((trimethylsilyl)methyl)benzyl)trimethylammonium iodide (5.) could be obtained only in the presence of its stable (4 + 2) and (4 + 4) dimers. The dimerizat… more
Date: September 21, 1990
Creator: Fischer, David
Partner: UNT Libraries Government Documents Department
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Platinum(II) complexes as spectroscopic probes for biomolecules

Description: The use of platinum(II) complexes as tags and probes for biomolecules is indeed advantageous for their reactivities can be selective for certain purposes through an interplay of mild reaction conditions and of the ligands bound to the platinum. The use of {sup 195}Pt NMR as a method of detecting platinum and its interactions with biomolecules was carried out with the simplest model of platinum(II) tagging to proteins. Variable-temperature {sup 195}Pt NMR spectroscopy proved useful in studying t… more
Date: September 21, 1990
Creator: Ratilla, Eva
Partner: UNT Libraries Government Documents Department
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Applications of solid state nuclear magnetic resonance techniques to the study of coals and polymers.

Description: The use of Nuclear Magnetic Resonance (NMR) to study molecules in the solid state has grown rapidly over the past several years. This is due to the advent of techniques which allow for the removal of certain interactions in the solid state which previously have thwarted most attempts at obtaining chemical shift or their anisotropies. With these parameters and others now available, NMR has become an important tool to be used in the understanding of the chemistry of solids. The work reported in t… more
Date: January 1, 1979
Creator: Pembleton, R. G.
Partner: UNT Libraries Government Documents Department
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A small low energy cyclotron for radioisotope measurements

Description: Direct detection of {sup 14}C by accelerator mass spectrometry has proved to be a much more sensitive method for radiocarbon dating than the decay counting method invented earlier by Libby. A small cyclotron (the cyclotrino'') was proposed for direct detection of radiocarbon in 1980. This combined the suppression of background through the use of negative ions, which had been used effectively in tandem accelerators, with the high intrinsic mass resolution of a cyclotron. Development of a small e… more
Date: November 1, 1989
Creator: Bertsche, Kirk Joseph
Partner: UNT Libraries Government Documents Department
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Studies of fundamental properties of rutherfordium (Element 104) using organic complexing agents

Description: Chemical properties of rutherfordium (Rf) have been investigated with the organic ligands triisooctylamine (TIOA), tributylphosphate (TBP), and thenoyltrifluoroacetone (TTA). The TIOA studies showed that Rf behaves differently than Th and Eu and most similarly to Zr, only Zr and Rf extract from 12 M HCI. This result is further evidence that Rf is a Group 4 element. Studies with TBP showed that Rf chemical behavior differed from the other Group 4 elements. The extraction by TBP at different chlo… more
Date: April 1, 1992
Creator: Czerwinski, K. R.
Partner: UNT Libraries Government Documents Department
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Two-proton pickup studies with the (6Li,8B) reaction

Description: The (/sup 6/Li,/sup 8/B) reaction has been investigated on targets of /sup 26/Mg, /sup 24/Mg, /sup 16/O, /sup 13/C, /sup 12/C, /sup 11/B, /sup 10/B, and /sup 9/Be at a bombarding energy of 80.0 MeV, and on targets of /sup 16/O, /sup 12/C, /sup 9/Be, /sup 7/Li, and /sup 6/Li at a bombarding energy of 93.3 MeV. Only levels consistent with direct, single-step two-proton pickup reaction mechanisms were observed to be strongly populated. On T/sub z/ = 0 targets, the spectroscopic selectivity of this… more
Date: December 3, 1976
Creator: Weisenmiller, Robert Benjamin
Partner: UNT Libraries Government Documents Department
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Actinide Production in the Reaction of Heavy Ions withCurium-248

Description: Chemical experiments were performed to examine the usefulness of heavy ion transfer reactions in producing new, neutron-rich actinide nuclides. A general quasi-elastic to deep-inelastic mechanism is proposed, and the utility of this method as opposed to other methods (e.g. complete fusion) is discussed. The relative merits of various techniques of actinide target synthesis are discussed. A description is given of a target system designed to remove the large amounts of heat generated by the pass… more
Date: July 1, 1983
Creator: Moody, K. J.
Partner: UNT Libraries Government Documents Department
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NUCLEAR SPECTROSCOPIC STUDIES OF SOME VERY HEAVY ODD-MASS NUCLIDES

Description: The nuclear radiations of nuclides: U{sup 233}, Pu{sup 239}, Bk{sup 243}, Bk{sup 244}, Bk{sup 245}, Bk{sup 246}, Bk{sup 249}, Cf{sup 249}, and Fm{sup 255} were investigated with high-resolution spectrometers. The {alpha}-particle spectra of all nuclides except Bk{sup 249} were measured with 6 mm diameter surface-barrier detectors. Bk{sup 249} {alpha}-particles were analyzed with a double-focusing magnetic spectrograph. The {gamma}-singles were examined with the recently developed Ge(Li) and Si(… more
Date: September 20, 1966
Creator: Ahmad, Irshad
Partner: UNT Libraries Government Documents Department
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Alpha-Decay Studies in the Heavy-Element Region

Description: Using primarily a 75-cm radius of curvature 60 deg symmetrical electromagnetic analyzer, a study of the complexity of the following alpha spectra was made: Es/sup 253/, Cf/sup 246/, Cm/sup 244/, Am/sup 243/, Pu/sup 236,242/, Pa/sup 231/ , Th/sup 227,230/, Ac/sup 225/, At/sup 209/ and Po/sup 206/. An investigation of the gamma rays associated with the following isotopes was also madei /sup 236/, and Pa/sup 231/. Decay schemes have been suggested for most of the isotopes included in this study. T… more
Date: July 1, 1956
Creator: Hummel, J. P.
Partner: UNT Libraries Government Documents Department
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Vibrational state-resolved differential cross sections for the D + H sub 2 yields DH + H reaction

Description: In this thesis, crossed-molecular-beams studies of the reaction D + H{sub 2} {yields} DH + H at collision energies of 0.53 and 1.01 eV are reported. Chapter 1 provides a survey of important experimental and theoretical studies on the dynamics of the hydrogen exchange reaction. Chapter 2 discusses the development of the excimer-laser photolysis D atom beam source that was used in these studies and preliminary experiments on the D + H{sub 2} reaction. In Chapter 3, the differential cross section … more
Date: November 1, 1989
Creator: Continetti, Robert Elliot
Partner: UNT Libraries Government Documents Department
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STUDIES IN THE NUCLEAR CHEMISTRY OF PLUTONIUM, AMERICIUM, AND CURIUM AND MASSES OF THE HEAVIEST ELEMENTS

Description: Ion exchange column elution methods for the separation of americium and curium using tartrate and lactate solutions have been developed which are superior to citrate elutions. Tartrate elutions are suitable for slow separations and lactate elutions are satisfactory for general use where rapid separations are required. Fission and spallation products were isolated from Pu{sup 239} targets which had been bombarded with alpha particles of 21 to 37 Mev energy. Fission yield curves as well as fissio… more
Date: April 20, 1954
Creator: Glass, Richard Alois
Partner: UNT Libraries Government Documents Department
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Fission of Gold With 112-Mev C{sup 12} Ions: A Yield-Mass and Charge- Distribution Study

Description: Fission prcduct cross sections were measured radiochemically and mass- spectrometrically for gold bombsrded with 112-Mev C/sup 12/ ions. Cross sections for 43 nuclides were measured for elements from nickel to barium. Thirty-six yields are either primary fission product yields (independent yields) or were corrected (with less than 25% correction) so as to represent independent yields. The independent yields were empirically systematized and a yield-mass curve was constructed. The yield-mass cur… more
Date: May 23, 1960
Creator: Blann, H. M.
Partner: UNT Libraries Government Documents Department
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Nuclear Forensics Attributing the Source of Spent Fuel Used in an RDD Event

Description: An RDD attack against the U.S. is something America needs to prepare against. If such an event occurs the ability to quickly identify the source of the radiological material used in an RDD would aid investigators in identifying the perpetrators. Spent fuel is one of the most dangerous possible radiological sources for an RDD. In this work, a forensics methodology was developed and implemented to attribute spent fuel to a source reactor. The specific attributes determined are the spent fuel burn… more
Date: June 1, 2005
Creator: Scott, M.R.
Partner: UNT Libraries Government Documents Department
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High-Energy Beta Decay of Light Elements

Description: The beta decay of the radioactive members of the mass-eight and -twelve triads has been studied with a spiral-orbit spectrometer having a 1.3% resolution. The end point, half-life and log-ft values respectively are: for N{sup 12}, 16.37 {+-} 0.06 MeV, 11.43 {+-} 0.05 milliseconds, and 4.17; for B{sup 12}, 13.40 {+-} 0.05 MeV, 20.6 {+-} 0.2 msec and 4.11; for B{sup 8}, 14 MeV (broad), 0.75 {+-} 0.02 sec, and 5.72; and for Li{sup 8}, 13 Mev (broad), 0.87 {+-} 0.01 sec, and 5.67. The mass excesses… more
Date: June 16, 1958
Creator: Vedder, James F
Partner: UNT Libraries Government Documents Department
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Development of odd-Z-projectile reactions for transactinide element synthesis

Description: The development of new odd-Z-projectile reactions leading to the production of transactinide elements is described. The cross section of the even-Z-projectile 208Pb(64Ni, n)271Ds reaction was measured at two new energies using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. In total, seven decay chains attributable to 271Ds were observed. These data, combined with previous results, establish an excitation function for the production of 271Ds. Th… more
Date: November 4, 2004
Creator: Folden III, Charles Marvin
Partner: UNT Libraries Government Documents Department
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