Chloride anion exchange coprocessing for recovery of plutonium from pyrochemical residues and Cs sub 2 PuCl sub 6 filtrate (open access)

Chloride anion exchange coprocessing for recovery of plutonium from pyrochemical residues and Cs sub 2 PuCl sub 6 filtrate

Continuing studies of plutonium recovery from direct oxide reduction (DOR) and electrorefining (ER) pyrochemical process residues show that chloride anion exchange coprocessing is useful and effective. Coprocessing utilizes DOR residue salt as a reagent to supply the bulk of chloride ion needed for the chloride anion exchange process and to improve ER residue salt solubility. ER residue salt and ER scrapeout can be successfully treated, either alone or together, using coprocessing. In addition, chloride anion exchange at 2.0M acidity results in improved process performance by greatly reducing disproportionation of plutonium(IV), eliminating restrictions on oxidation time compared to operation at 1.0M acidity. Laboratory-scale experiments show that below-discard effluent plutonium losses are obtained. Resin capacity was 30 g Pu/{ell} or greater. Furthermore, it is feasible to perform chloride anion exchange recovery of plutonium from filtrate resulting from precipitation of dicesium hexachloroplutonate (Cs{sub 2}PuCl{sub 6}, an oxidant salt to be used in the molten salt extraction process) and integration of its preparation with recovery of DOR salts. 10 refs., 9 figs., 10 tabs.
Date: December 7, 1990
Creator: Muscatello, A. C. & Killion, M. E.
Object Type: Report
System: The UNT Digital Library
Thermally Induced Structural Changes in Coal Combustion (open access)

Thermally Induced Structural Changes in Coal Combustion

The project objectives are (1) to measure the effect of devolatilization temperature and time on properties of the char and (2) characterize and quantify the effect of thermal annealing on char reactivity during char burnout under conditions of pulverized combustion. Coal devolatilization runs continued during the reporting period. Elemental analysis and N{sub 2} BET surface areas measurements were carried out on the three chars produced in the devolatilization runs. The results are presented. Experiments in the electrodynamic balance during the reporting period were focused on developing ways to measure the particle mass loss and, therefore, the reaction rate directly. This work is summarized in the attached Appendix. 4 refs., 1 fig., 1 tab.
Date: December 7, 1990
Creator: Gavalas, G. R. & Flagan, R. C.
Object Type: Report
System: The UNT Digital Library
A photoemission investigation of compound semiconductor monodisperse clusters (open access)

A photoemission investigation of compound semiconductor monodisperse clusters

We have used synchrotron radiation photoemission to probe the valence and core level electronic structure of compound-semiconductor monodisperse clusters (nanocrystals). These clusters exhibited a 10% or less variation relative to the mean diameter and were attached to the metal substrates via alkane chains. Direct evidence of gap broadening due to size variation in CdS clusters was observed. The novel utilization of alkane chain attachment is the key to eliminating the otherwise debilitating problem of sample charging, as occurs with powders. The quality of sample preparation was confirmed by other methods such as transmission electron microscopy, Raman scattering and x-ray diffraction. This work provides a direct link between photoemission studies of expitaxial ultra-thin films of compound semiconductors, the photon-spectroscopy measurements of cluster powders and the existing theories of quantum confinement in reduced dimensionality structures. 5 refs., 2 figs.
Date: December 7, 1990
Creator: Tobin, J. G. (Lawrence Livermore National Lab., CA (USA)); Colvin, V. L. & Alivisatos, A. P. (California Univ., Berkeley, CA (USA))
Object Type: Article
System: The UNT Digital Library
Molecular cytogenetics using fluorescence in situ hybridization (open access)

Molecular cytogenetics using fluorescence in situ hybridization

Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.
Date: December 7, 1990
Creator: Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U. & Yu, Loh-Chung.
Object Type: Article
System: The UNT Digital Library
A technique for shell compression measurements of laser fusion targets by neutron activation of a rubidium tracer (open access)

A technique for shell compression measurements of laser fusion targets by neutron activation of a rubidium tracer

At the Nova Laser, the activation of a rubidium tracer incorporated in the shell of ICF targets has become a standard diagnostic technique for measuring the compressed shell areal density {l angle}{rho}{Delta}R{r angle}. The isotope {sup 85}Rb is activated by 14 MeV implosion neutrons to produce the isomer {sup 84m}Rb(t{sub {1/2}} = 20.5 min) which is used to determine the shell {l angle}{rho}{Delta}R{r angle} while the radioactive isotope {sup 86}Rb(t{sub 1/2} = 18.8 d) is used to determine the fraction of target debris collected as well as to assay the amount of rubidium in the target. The {sup 85}Rb(n,2n){sup 84m}Rb cross-section at 14.1 MeV was measured ({sigma} = 0.514 {plus minus} 0.080 b). Details of the detector system and experimental technique are given. 12 refs., 2 tabs.
Date: December 7, 1990
Creator: Lane, S.M. & Nelson, M.B.
Object Type: Article
System: The UNT Digital Library
Qualitative results from a beamstrahlung flight simulator (open access)

Qualitative results from a beamstrahlung flight simulator

A simulation code for beam-beam deflections and beamstrahlung fluxes for tilted and elliptic beams is presented. Some qualitative features of beamstrahlung scans are discussed. 8 refs., 11 figs.
Date: December 7, 1990
Creator: Ziemann, V.
Object Type: Report
System: The UNT Digital Library
Corrosion of copper in Mound's single-pass potable water systems (open access)

Corrosion of copper in Mound's single-pass potable water systems

An increase in the number of copper plumbing failures at Mound prompted a thorough analysis of the failed components. Most of the components were elbow joints. All of these parts exhibited the same type of accelerated deterioration. The failed parts were analyzed optically and by scanning electron microscopy. Water chemistry, solder, and soldering fluxes were evaluated to determine their possible roles in the accelerated attack. Cross-sectioning of the elbow joints revealed residual soldering flux and cutting burrs on the inside of the elbows. Water analysis showed Mound's water was rated as corrosive. Recommendations for improved workmanship and design are presented. Testing of potable water at a regular basis was also recommended. 8 refs., 10 figs., 3 tabs.
Date: December 7, 1990
Creator: Schleitweiler, Patrick M. & Miller, Pamela S.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 15, Number 91, Pages 6961-7060, December 7, 1990 (open access)

Texas Register, Volume 15, Number 91, Pages 6961-7060, December 7, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: December 7, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Attorney General Opinion: LO90-108 (open access)

Texas Attorney General Opinion: LO90-108

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Can a municipality require a bond, either a performance and/or payment bond, from a developer if it also requires surety from the same developer that the project will be completed? What determines 'sufficient surety'? Does the statute permit a municipality to accept forms of guarantee, such a letter of credit, in lieu of a performance and/or payment bond?
Date: December 7, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Strange meson and strangeonium spectroscopy: Introduction (open access)

Strange meson and strangeonium spectroscopy: Introduction

None
Date: December 7, 1990
Creator: Dunwoodie, W.
Object Type: Article
System: The UNT Digital Library
Timing between streak cameras with a precision of 10 ps (open access)

Timing between streak cameras with a precision of 10 ps

The laser beams irradiating a target at the Nova laser facility comprise a set of ten simultaneous events. Two streak cameras, whose resolutions are 40 ps, record the power history for each beam, five beams to a camera; their time bases are cross-timed with a fiducial pulse. Analysis of data recorded for target experiments conducted over a six month period show the precision for cross-timing signals between two streak cameras to be {plus minus}9 ps and for characterizing a single temporal feature of a pulse to be {plus minus}5 ps. Beam synchronization at the end of six months was within 20 ps of the synchronization at the beginning of the experiments. A beam timing shift greater than 25 ps can be detected on a single laser shot; shifts of 10 to 20 ps require several shots to detect. 2 refs., 6 figs.
Date: December 7, 1990
Creator: Lerche, R. A.
Object Type: Article
System: The UNT Digital Library