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Defect structures in YBa/sub 2/Cu/sub 3/O/sub 7-x/ produced by electron irradiation

Description: Defect structures in YBa/sub 2/Cu/sub 3/O/sub 7-x/ produced by electron irradiation at 300/sup 0/ K were investigated by transmission electron microscopy. Threshold energies for the production of visible defects were determined to be 152 keV and 131 keV (+- 7 keV) in directions near the a and b (b > a) axes (both perpendicular to c, the long axis in the orthorhombic structure), respectively. During above threshold irradiations in an electron flux of 3 x 10/sup 18/ cm/sup -2/ s/sup -1/, extended… more
Date: December 1, 1987
Creator: Kirk, M.A.; Baker, M.C.; Liu, J.Z.; Lam, D.J. & Weber, H.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Comparisons of VUU (Vlasov-Uehling-Uhlenbeck) predictions with streamer chamber data

Description: Experimental charged particle inclusive and exclusive parameters for several nuclear systems are compared with microscopic model predictions based on the Vlasov-Uehling-Uhlenbeck equation, for various density-dependent nuclear equations of state (EOS). Inclusive variables and multiplicity distributions are in good agreement, and are not sensitive to the EOS. Rapidity spectra show evidence of being useful in determining whether the model uses the correct sections for binary collisions in the nuc… more
Date: January 1, 1987
Creator: Keane, D.; Chu, S.Y.; Fung, S.Y.; Liu, Y.M.; Qiao, L.J.; VanDalen, G. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The EPRI Laboratory experiments at ANL. [Vaporization of core-concrete mixtures]

Description: The vaporization of core-concrete mixtures is being measured using a transpiration method. Mixtures of stainless steel, concrete (limestone or basaltic) and urania (doped with La/sub 2/O/sub 3/, SrO, BaO, and ZrO/sub 2/) are vaporized at 2150 - 2400 K from a zirconia crucible into flowing He - 6% H/sub 2/ gas. Up to 600 ppM H/sub 2/O is added to the gas to fix the partial molar free energy of oxygen in the range -420 kJ to -550 kJ. The fraction of the sample that is vaporized is determined by w… more
Date: October 28, 1987
Creator: Roche, M. F.; Settle, J. L.; Leibowitz, L.; Johnson, C. E. & Ritzman, R. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Positron-annihilation 2D-ACAR studies of disordered and defected alloys

Description: Theoretical and experimental progess in connection with 2D-ACAR positron annihilation studies of ordered, disordered, and defected alloys is discussed. We present, in particular, some of the recent developments concerning the electronic structure of disordered alloys, and the work in the area of annihilation from positrons trapped at vacancy-type defects in metals and alloys. The electronic structure and properties of a number of compounds are also discussed briefly; we comment specifically on … more
Date: September 1, 1987
Creator: Bansil, A.; Prasad, R.; Smedskjaer, L. C.; Benedek, R. & Mijnarends, P. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Actinide removal from aqueous solution with activated magnetite

Description: An actinide aqueous waste treatment process using activated magnetite has been developed at Rocky Flats. The use and effectiveness of various magnetites in lowering actinide concentrations in aqueous solution are described. Experiments indicate that magnetite particle size and pretreatment (activation of the magnetite surface with hydroxyl ions greatly influence the effective use of magnetite as an actinide adsorbent. With respect to actinide removal, Ba(OH)/sub 2/-activated magnetite was more … more
Date: August 10, 1987
Creator: Kochen, R.L. & Thomas, R.L. (ed.)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Radiation damage in YBa/sub 2/Cu/sub 3/O/sub 7/ by fast neutrons

Description: The superconducting transition temperature of sintered YBa/sub 2/Cu/sub 3/O/sub 7/ decreases at a rate of 2.7 K/10/sup 18/ n/cm/sup 2/ (E > 0.1 MeV) for fast neutron irradiation. The critical current density J/sub c/ increases a factor of three at zero field and more than three at nonzero fields for fluences up to 2 x 10/sup 18/ n/cm/sup 2/. At both 7 and 75 K, J/sub c/ is decreasing with fluence near 3 x 10/sup 18/ n/cm/sup 2/.
Date: January 1, 1987
Creator: Willis, J. O.; Cost, J. R.; Brown, R. D.; Thompson, J. D. & Peterson, D. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Resistivity of EuBa/sub 2/(Cu/sub 1-y/Zn/sub y/)/sub 3/O/sub x/ as a function of temperature, magnetic field, pressure and Zn concentration

Description: We report electrical resistance and magnetoresistance measurements on EuBa/sub 2/(Cu/sub 1-y/Zn/sub y/)/sub 3/O/sub x/ under pressure to 17 kbar. With Zn substitution, T/sub c/ is depressed rapidly (approx.19 K/at.% Zn) and there are qualitative changes in the temperature and field response of the resistance. Pressure drives the Zn-substituted samples toward undoped EuBa/sub 2/Cu/sub 3/O/sub x/ behavior. Analysis of the temperature dependent resistance for y = 0.05 and P = O, together with Hall… more
Date: January 1, 1987
Creator: Borges, H. A.; Wells, G. L.; Cheong, S. W.; Kwok, R. S.; Thompson, J. D.; Fisk, Z. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Experiments on Heavy Electron and High T/sub c/ Oxide Superconductors. [Gd-doped (U,Th)Be/sub 13/; RBa/sub 2/Cu/sub 3/O/sub 7/]

Description: In the first part of this paper, we briefly describe some of our efforts to determine the type of pairing and pairing mechanisms that are associated with the superconductivity of heavy electron materials by means of H/sub c2/(T) measurements in Gd-doped (U/sub 1-x/Th/sub x/)Be/sub 13/ alloys. An account of some of our recent work on the new high T/sub c/ copper oxide superconductors is given in the second part of the paper. 30 refs., 12 figs.
Date: January 1, 1987
Creator: Maple, M. B.; Dalichaouch, Y.; Ferreira, J. M.; Hake, R. R.; Lambert, S. E.; Lee, B. W. et al.
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Partner: UNT Libraries Government Documents Department
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Kinetics of fission product release prior to fuel slumping

Description: This paper describes the primary physical/chemical models recently incorporated into a mechanistic code (FASTGRASS) for the estimation of fission product release from fuel, and compares predicted results with test data. The theory of noble gas behavior is discussed in relation to its effect on the release behavior of I, Cs, Te, Ba, and Sr. The behavior of these fission products in the presence of fuel liquefaction/dissolution and oxidation grain-growth phenomena is presented, as is the chemistr… more
Date: October 1, 1987
Creator: Rest, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Geochemical modeling research related to the surface disposal of processed oil shale solid waste. [Elements and compounds in oil shale wastes]

Description: Several geochemical codes are available in the literature to model chemical processes such as oxidation-reduction, precipitation-dissolution, formation of solution complex, adsorption, and ion exchange. However, these models differ in the environments to which they apply. The objective of this research was to evaluate the applicability of existing geochemical codes to predict water quality from an oil shale solid waste environment. We selected EQ3/EQ6, GEOCHEM, MINTEQ, PHREEQE, SOLMNEQ, and WAT… more
Date: October 1, 1987
Creator: Reddy, K. J. & Drever, J. I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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