A5046119967- Radioactive element chemistry and processing
- Nuclear Physics and Applications
- Radioactive contamination and transfer
- Nuclear physics research studies
- Nuclear and radioactivity studies
- Radioactivity and Radon Measurements
- Nuclear Issues and Defense
- Chemical Synthesis and Characterization
- Radiation Detection and Scintillator Technologies
- Chemical Thermodynamics and Molecular Structure
- Nuclear reactor physics and engineering
- Ion-surface interactions and analysis
- Crystallization and Solubility Studies
- Analytical chemistry methods development
- Graphite, nuclear technology, radiation studies
- Nuclear Materials and Properties
- Laser-induced spectroscopy and plasma
- Astronomical and nuclear sciences
- X-ray Diffraction in Crystallography
- Medical Imaging Techniques and Applications
- Cold Fusion and Nuclear Reactions
- Radiopharmaceutical Chemistry and Applications
- Crystallography and molecular interactions
- Radiation Dose and Imaging
- Luminescence Properties of Advanced Materials
University of Tennessee at Knoxville
2014-2023
Oak Ridge National Laboratory
2011-2019
Office of Nuclear Energy
2015-2018
Knoxville College
2011-2017
ETH Zurich
2011
Lawrence Livermore National Laboratory
1987-2005
University of California, Davis
2003
Florida Department of Health
2003
University of California, Berkeley
1987-1994
Lawrence Berkeley National Laboratory
1987-1994
The rapid chemical analysis of individual cells is an analytical capability that will profoundly impact many fields including bioaerosol detection for biodefense and cellular diagnostics clinical medicine. This article describes a mass spectrometry-based technique the real-time reagentless characterization airborne without sample preparation. We characterize spectral signature Bacillus spores demonstrate ability to distinguish two spore species, B. thuringiensis atrophaeus, from one another...
Degrapol® and PLGA electrospun fiber fleeces were characterized with regard to diameter, alignment, mechanical properties as well scaffold porosity. The study showed that electrospinning parameters affect diameter alignment in an inverse relation: was increased flow rate, decrease working distance collector velocity, whereas the velocity but decreased rate. When or PLGA-polymers co-spun increasing ratios of a water-soluble polymer subsequently removed; fibrous scaffolds porosities obtained....
Titanium implants are most commonly used for bone augmentation and replacement due to their favorable osseointegration properties.Here, hyperhydrophilic sand-blasted acid-etched (SBA) titanium surfaces were produced by alkali treatment responses partially heparinized whole human blood analyzed.Blood clot formation, platelet activation of the complement system was analyzed revealing that exposure time between material surface is crucial as increasing results in higher amount activated...
Studies of the halide complexation element 105 in aqueous solution were performed on 34-s 262 Ha produced 249 Bk( ls O,5n) reaction.The was detected by measuring fission and alpha activities associated with its decay decays daughter, 4.3-s 258 Lr.Time-correlated pairs parent daughter particles provided a unique identification presence Ha.About 1600 anion exchange separations from HCl mixed HC1/HF solutions one-minute time scale.Reversed-phase micro-chromatographic columns incorporating...
Excitation functions have been measured for production of isotopes Th through Fm in bombardments $^{248}\mathrm{Cm}$ with 231- to 323-MeV $^{44}\mathrm{Ca}$ ions and the Cm 230- 291-MeV $^{40}\mathrm{Ca}$ ions, respectively, using radiochemical methods. Upper cross section limits were established nuclides that not positively detected. The experimental data compared results previous reaction studies systems $^{40}\mathrm{Ca}$${+}^{248}$Cm $^{48}\mathrm{Ca}$${+}^{248}$Cm. half-widths Gaussian...
The 7.6-h isotope $^{256}\mathrm{Es}^{\mathrm{m}}$ was produced from a 2.5-\ensuremath{\mu}g/${\mathrm{cm}}^{2}$ target of $^{254}\mathrm{Es}$ by the (t,p) reaction. reaction products were separated radiochemically, and decay properties determined via \ensuremath{\beta}-\ensuremath{\gamma}, \ensuremath{\gamma}-\ensuremath{\gamma}, \ensuremath{\beta}-fission correlation techniques. From these measurements we able to assign 57 \ensuremath{\gamma} rays 26 levels in daughter $^{256}\mathrm{Fm}$....
A method for producing synthetic debris similar to the melt glass produced by nuclear surface testing is demonstrated. Melt from first weapon test (commonly referred as trinitite) used benchmark this study. These surrogates can be simulate a variety of scenarios and will serve tool developing validating forensic analysis methods.
Eu2+-activated strontium iodide is an excellent single crystal scintillator used for gamma-ray detection, and significant effort currently focused on the development of large-scale growth techniques. A new approach molten-salt pumping or so-called melt aging was recently applied to optimize quality scintillation performance. Nevertheless, a detailed understanding underlying mechanism this technique still lacking. The main purpose paper conduct in-depth study interplay between microstructure,...
We have measured the mass and kinetic-energy distributions of fragments from spontaneous fission $^{256}\mathrm{No}$ produced via $^{248}\mathrm{Cm}$${(}^{12}$C,4n) reaction. The production cross section using 71-MeV $^{12}\mathrm{C}$ projectiles was found to be 250 nb. total kinetic energy for is 196\ifmmode\pm\else\textpm\fi{}3 MeV. distribution very broad (full width at half maximum \ensuremath{\sim}50 units) with no appreciable decrease in yield symmetric division. seems transition...
A hand-held device for laser-induced breakdown spectroscopy has been investigated the determination of uranyl fluoride surface contamination. This research demonstrates ability to successfully detect uranium on surfaces when using a low resolving power (λ/Δλ=4000) spectrograph, with 5 mJ energy per 1 ns pulsed laser radiation, available as commercially packaged system. Sand/uranyl mixtures are prepared simulate residue likely encountered during decontamination efforts at facilities that...
Thermoluminescence and phototransferred thermoluminescence measurements of protective glass from smartphones are described. Samples Gorilla Glass were examined nine different manufacturers 40 phone models. Additionally, 12 glasses believed to be original equipment manufacturer replacements, as well three samples U.S. finishers, also studied. Altogether, 99 examined. The radiation-induced signal produced glow curve shapes specific the generations could used distinguish between them. A...
Delayed fission following the electron-capture decay of $^{234}\mathrm{Am}$ was studied. The $^{237}\mathrm{Np}$(\ensuremath{\alpha},7n${)}^{234}$Am reaction with multiple $^{237}\mathrm{Np}$ targets used to produce $^{234}\mathrm{Am}$. properties and half-life were measured using a rotating-wheel system. determined be 2.32\ifmmode\pm\else\textpm\fi{}0.08 min from measurements activity. A highly asymmetric mass-yield distribution observed for activity, average total kinetic energy fragments...
Following a major shortage of 99Mo in the 2009–2010 period, concern grew that aging reactor production facilities needed to be replaced. Most producers were using highly enriched 235U (HEU) as target material. The Organisation for Economic Co-...Read More
Knowledge-based design of extracting agents for selective binding actinides is essential in stock-pile stewardship, environmental remediation, separations, and nuclear fuel disposal. Robust computational protocols are critical depth understanding structural properties to further advance the ligands. In particular, rapid radiochemical separations require predictive capabilities gas phase. This study focuses on gas-phase preferences cyclic imide dioximes uranyl, neptunyl, plutonyl, americyl....
This work reports the thermodynamic characterizations of organometallic species as a vehicle for rapid separation volatile nuclear fission products via gas chromatography due to differences in adsorption enthalpy. Because and sublimation thermodynamics are linearly correlated, there is considerable motivation determine enthalpies. A method isothermal thermogravimetric analysis, TGA-MS melting point analysis employed on thirteen lanthanide 1,1,1,5,5,5-hexafluoroacetylacetone complexes An...
Abstract C(α), N ‐Carboalkoxyhydrazones were metalated with an excess of lithium diisopropylamide (LDA), and the resulting dianions condensed methyl iodide, unsubstituted ketone, a benzoate ester, salicylates, benzoylacetate, or ethyl chloroformate.
Efficient predictive capabilities are essential for the actinide series since regulatory constraints radioactive work, associated costs needed specialized facilities, and short half-lives of many actinides present great challenges in laboratory settings. Improved accuracy is advantageous numerous applications including optimization design separation agents nuclear fuel waste. One limitation calculations support these that large variations observed from predictions obtained with currently...
Abstract C (α), O ‐Dilithiooximes, N ‐dilithiophenylhydrazones, or ‐dilithioacylhydrazones were prepared in an excess of lithium diisopropylamide (LDA) and condensed with a variety esters followed by acid‐cyclization to give substituted isoxazoles pyrazoles.