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Radium-Barium Separation Process: Part 2 - Chromate Fractionation Procedures

Description: Abstract: A comprehensive study was made of various fractionation systems for the fractional separation of barium-radium mixtures. The most efficient and simplest fractionation scheme was chosen on the basis of the thermodynamics of separating the constituents of mixed crystals and of the combining fractions in a system of repeating composition. This scheme was applied to the separation of barium and radium by utilizing the countercurrent batch fractionation of the chromates. The chromate procedure was evaluated by a comparison with the classic methods which employ the fractional crystallization of the halides. The chromate method is more practical on the basis of radium enrichment per fractionation step, control of precipitating conditions, simplicity, and speed of operation.
Date: April 1, 1951
Creator: Salutsky, Murrell Leon; Stites, J. G. & Joy, E. F.
Partner: UNT Libraries Government Documents Department


Description: The half life of cesium-137 was determined to be 29.2 plus or minus 0.3 years by an all mass spectrometric method. The abundance of the 662 Kev gamma- ray in the decay scheme was found to be 0.82 plus or minus 0.03 per beta disintegration. In the course of the work, the isotopic distribution of natural barium was determined with improved accuracy to be (72.11 plus or minus 0.06)% 138, (11.18 plus or minus 0.05)% 137, (7.77 plus or minus 0.02)% 136, (6.42 plus or minus 0.03)% 135, (2.33 plus or minus 0.02)% 134, (0.091 plus or minus 0.003)% 132, and (0.098 plus or minus 0.002)% 130. (auth)
Date: June 1, 1962
Creator: Rider, B.F.; Peterson, J.P. Jr. & Ruiz, C.P.
Partner: UNT Libraries Government Documents Department

Properties of Glasses in Some Ternary Systems Containing BaO and SiO2

Description: Report discussing the glass forming regions in six ternary oxide systems containing BaO, Si02, and a third oxide. The properties of the resulting glasses were measured and the results reported. The data on refractive indices, dispersions, and specific volumes were evaluated by computer methods in an attempt to identify "substructures" containing the cations present in the glasses.
Date: September 1973
Creator: Cleek, Given W. & Babcock, C. L.
Partner: UNT Libraries Government Documents Department

Stoichiometry and Deposition Temperature Dependence of the Microstructural and Electrical Properties of Barium Strontium Titanate Thin Films

Description: Barium Strontium Titanate (BST) was deposited on Pt/ZrO2 / SiO2/Si substrates using liquid source metal organic chemical vapor deposition. A stoichiometry series was deposited with various GrII/Ti ratios (0.658 to 1.022) and a temperature series was deposited at 550 to 700°C. The thin films were characterized using transmission electron microscopy. Both series of samples contained cubic perovskite BST and an amorphous phase. The grain size increased and the volume fraction of amorphous phase decreased with increasing deposition temperature. The electrical and microstructural properties improved as the GrII/Ti ratio approached 1 and deteriorated beyond 1. This research demonstrates that BST thin films are a strong candidate for future MOS transistor gate insulator applications.
Date: May 1998
Creator: Pena, Piedad
Partner: UNT Libraries

Scintillation Properties of Eu2+-Activated Barium Fluoroiodide

Description: The scintillation properties of powders and single-crystals of BaFI doped with Eu2+ are presented. Single crystals were grown by the vertical Bridgman technique. Under optical and X-ray excitation, the samples exhibit a narrow E2+ 5d-4f transition emission centered at 405 nm. The scintillation light output is estimated to be 55,000+-5,000 photons/MeV at 662 keV with 85percent of the light decaying within 600 ns. An energyresolution of 8.5percent full width at half maximum (FWHM) has been achieved using this scintillator for 662 keV excitation (137Cs source) at room temperature.
Date: November 18, 2009
Creator: Gundiah, Gautam; Bourret-Courchesne, Edith; Bizarri, Gregory; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew et al.
Partner: UNT Libraries Government Documents Department


Description: This report describes work done in the pilot plant at Msllinckrodt toward development of a recovery process for U in BaSO/sub 4/ take. The investigation involved examination of chemical leaching problems, and testing of filtration equipment for recovery of the leached cake. Several additional problems uncovered during the work were introduction of the BaSO/sub 4/ cake into a slurry, settling of heavy fines in process equipment, and forming of the BaS0/ sub 4/ slurry. (auth)
Date: May 1, 1953
Creator: Kirby, A.M.
Partner: UNT Libraries Government Documents Department

H- Enhancement Process in a Multicusp Ion Source Operated with a Barium Insert Structure

Description: It has been demonstrated that the H{sup -} output current from a small multicusp source can be substantially enhanced if the hydrogen plasma is seeded with barium. Operating with a barium washer insert at the extraction aperture, it is found that the extractable H{sup -} current is increased by a factor of three if the insert bias potential is optimized. By use of a mixture of xenon and hydrogen gas, it is further demonstrated that the positive hydrogen ions are responsible for the observed H{sup -} enhancement.
Date: May 1, 1990
Creator: Leung, K.N.; Van Os, C.F.A. & Kunkel, W.B.
Partner: UNT Libraries Government Documents Department


Description: A review of the nuclear and chemical features of particular interest to the radiochemist, a dicusston of problems of dissolution of a sample and counting techniques, and a collectton of radiochemical procedures for the elements as found in the literature are given. (W.L.H)
Date: January 1, 1960
Creator: Sunderman, D.N. & Townley, C.W.
Partner: UNT Libraries Government Documents Department

Loss of Radioactivity from Barium Carbonate Samples

Description: The exchange loss of radioactivity from solid samplos of barium carbonate through the agency of carbonic acid and its ions has been investigated under a variety of conditions. It is concluded that the losses observed are greatly dependent upon the method of sample preparation, in particular the nature or any heat treatment which the sample materials undergo.
Date: January 9, 1948
Creator: Yankwich, Peter E.
Partner: UNT Libraries Government Documents Department


Description: The effects of backscattering upon self-absorption correction curves are demonstrated. Data are given for the backscattering powers of several substances for the beta radiations from C{sup 14}, and for se1f-absorption of samples of barium carbonate and wax, containing C{sup 14}, mounted on aluminum.
Date: January 1, 1948
Creator: Yankwich, Peter E. & Weigl, John.
Partner: UNT Libraries Government Documents Department

Spiral order in Ba{sub 2}CuGe{sub 2}O{sub 7}

Description: The quasi 2-D square-lattice antiferromagnet Ba{sub 2}CuGe{sub 2}O{sub 7} was studied by neutron scattering and bulk magnetic techniques. An incommensurate magnetic spiral structure with the propagation vector (1+{xi}, 1+{xi}, 0)({xi}=0.027) was observed below T{sub N}=3.26 K. Spin dynamics can be adequately described by conventional spin-wave theory with two exchange constants: nearest- neighbor in-plant antiferromagnetic coupling J{sub 1}{approx}0.48 meV and interplane ferromagnetic interaction J{sub 3}{approx}0.013 meV. This set of exchange parameters apparently fails to explain the spiral order. The non-centrosymmetric crystal structure suggests that the incommensurate phase may be the result of a Dzyaloshinskii-Moriya instability of the Neel ground state.
Date: August 1, 1996
Creator: Zheludev, A.; Shirane, G.; Sasago, Y.; Koide, N. & Uchinokura, K.
Partner: UNT Libraries Government Documents Department

Crossings in alternating-parity bands of neutron-rich Ba nuclei

Description: {sup 144}Ba and {sup 146}Ba nuclei produced in the spontaneous fission of {sup 248}Cm have been studied using the EUROGRAM II array. Spins and parities of excited levels have been deduced from triple-{gamma} angular correlation and direction-polarization correlation measurements, which is the first use of these techniques in studies of fission product nuclei. Ground-state, alternating-parity bands have been extended significantly and crossing in these bands has been found in both isotopes. For the first time alternating-parity band termination by particle alignment has been observed.
Date: July 22, 1995
Creator: Urban, W.; Jones, M.A. & Durell, J.L.
Partner: UNT Libraries Government Documents Department

Europium-doped barium bromide iodide

Description: Single crystals of Ba0.96Eu0.04BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl2 structure [Braekken (1932). Z. Kristallogr. 83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = +-0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement.
Date: October 21, 2009
Creator: Gundiah, Gautam; Hanrahan, Stephen M.; Hollander, Fredrick J. & Bourret-Courchesne, Edith D.
Partner: UNT Libraries Government Documents Department