Radiochemistry Commons^™

Measurement Of Spin-Flip Probabilities For Ultracold Neutrons Interacting With Nickel Phosphorus Coated Surfaces, Zhaowen Tang, Evan Robert Adamek, Aaron Brandt, Nathan Brannan Callahan, Steven M. Clayton, Scott Allister Currie, Takeyasu M. Ito, Mark F. Makela, Yasuhiro Masuda, Christopher L. Morris, Robert Wayne Pattie, John Clinton Ramsey, Daniel J. Salvat, Daniel J. Salvat, Alexander Saunders, Albert R. Young

Robert W. Pattie Jr.

A Generalized Method For Fissile Material Characterization Using Short-Lived Fission Product Gamma Spectroscopy, Justin Richard Knowles

Doctoral Dissertations

Characterizing the fissile content of nuclear materials is of particular interest to the safeguards and nuclear forensics communities. Short-lived fission product gamma spectroscopy offers a significant reduction in analysis time and detection limits when compared to traditional non-destructive assay measurements. Through this work, a fully generalizable method that can be applied to variations in fissile compositions and neutron spectra was developed for the modeling and measurement of short-lived fission product gamma-rays. This method uses a 238-group neutron flux that was characterized for two pneumatic tube positions in the High Flux Isotope Reactor using flux monitor irradiations. This flux spectrum was …

Actinium-225 Production Via Proton Irradiation Of Thorium-232, Justin Reed Griswold

Doctoral Dissertations

High energy proton spallation reactions on natural thorium metal targets have been utilized to produce multi mCi [milliCurie] quantities of Actinium-225. Theoretical cross sections for actinium and thorium isotopes as well as for a select number of the fission products produced in these reactions were generated by the Monte Carlo radiation transport code PHITS to simulate the experimental data obtained from sixteen irradiations of thorium metal targets with 25-210 µA [microampere] proton beams ranging in energies from 77 to 192 MeV. Irradiations were conducted at Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL), while target dissolution and processing …

Cyclotron Production And Biomedical Imaging Applications Of The Pet Isotope Manganese-52, Andrew Lake Wooten

McKelvey School of Engineering Theses & Dissertations

Manganese is an important element for biomedical research because of its roles as an essential micronutrient and as a neurotoxin from chronic elevated exposure, as well as the role of manganese(II) as a paramagnetic core for contrast agents in T1-weighted magnetic resonance imaging (MRI). Using a radiotracer of manganese provides excellent sensitivity for studying these phenomena, but only 52Mn met the criteria for our experiments: (1) a half-life (t1/2=5.6 days) that was long enough to examine timepoints over several days, (2) a half-life that was short enough to emit sufficient counts for a realistic scan time, and (3) emitted radiation …

Direct Dissolution And Electrochemical Investigation Of Cerium And Uranium In Ionic Liquid, Janelle Droessler

UNLV Theses, Dissertations, Professional Papers, and Capstones

The solubility, coordination and speciation of f-elements in ionic liquids (ILs) has been the focus of numerous studies because the purely ionic systems have unique physical properties that can be exploited in comparison to aqueous, organic, or molten salt systems. Ionic liquids are thermally stable, have negligible vapor pressure, and are electrochemically stable at negative potentials that encompass the reduction potential of actinide species. Literature has suggested that the properties of ILs could potentially be utilized in the nuclear fuel cycle for separations and reprocessing. However, the solubility of f-elements in ILs has been significantly lower compared to traditional solvents. …

Cd Transport In Eutectic Licl-Kcl And Contamination Of Zr Metal And Thermal Dehydration Of Bulk Licl-Kcl, Nicholas Azoy Earle

Masters Theses

Researchers at Idaho National Labs have noted unexpectedly high Cd content in empty cladding hulls after processing in the Mark-IV ER. It has been theorized that Cd metal is transporting from the LCC pool through the eutectic LiCl-KCl salt bath to the anode baskets containing the empty hull where it is retained as a Zr-Cd intermetallic. This study sought to replicate the Cd contamination in a dry Ar glovebox using small-scale analogue of the Mark-IV ER salt-Cd metal system.

Anhydrous eutectic LiCl-KCl was an essential regent in this research and experiments were conducted to investigate the feasibility of dehydrating nominally …

Synthesis Of A Novel Cox-2 Inhibitor Analog For Pet Scan Imaging, Rebecca Neighbor

Chancellor’s Honors Program Projects

No abstract provided.

Hydrogeochemical Modeling Of Saltwater Intrusion And Water Supply Augmentation In South Florida, Yonas T. Habtemichael

FIU Electronic Theses and Dissertations

The Biscayne Aquifer is a primary source of water supply in Southeast Florida. As a coastal aquifer, it is threatened by saltwater intrusion (SWI) when the natural groundwater flow is altered by over-pumping of groundwater. SWI is detrimental to the quality of fresh groundwater sources, making the water unfit for drinking due to mixing and reactions with aquifer minerals. Increasing water demand and complex environmental issues thus force water utilities in South Florida to sustainably manage saltwater intrusion and develop alternative water supplies (e.g., aquifer storage and recovery, ASR).

The objectives of this study were to develop and use calibrated …

The Design And Synthesis Of Ghrelin Analogues As Non‐Invasive Ghs‐R1a Imaging Probes, Carlie L. Charlton

Electronic Thesis and Dissertation Repository

The field of molecular imaging is constantly growing and evolving in order to provide the best possible healthcare for patients in various stages of disease and therapy. Molecular imaging aims to locate specific markers of disease by selectively targeting the markers of interest with high selectivity and visualizing the accumulation using external detection. The growth hormone secretagogue receptor-1a (GHS-R1a) has been shown to be involved in various important biological functions such as energy homeostasis and cardiac contractility. GHS-R1a has shown involvement in proliferation, migration and cell invasion of specific cancer subtypes. Therefore, targeting GHS-R1a is an important marker of different …

Design Rules For The Nucleation, Growth, And Encapsulation Of Gold Nanoparticles With Applications To Cancer Imaging, Matthew A. Wall

Dissertations, Theses, and Capstone Projects

Surface-enhanced Raman scattering (SERS) nanoparticles are exciting candidates for high-precision cancer imaging due to their highly specific spectral signature (Raman “fingerprint”) and propensity for passive targeting of cancerous tissues. However, the signal intensity of currently available SERS nanoparticles is insufficient for cancer imaging via passive targeting in most solid tumors. The overarching aim of this body of work is to develop a new generation of SERS nanoparticles with sufficiently low limits of detection to enable robust detection of various solid tumors in vivo.

The complexity of SERS nanoparticles requires significant advances to the theoretical and experimental understanding of metal …

Plutonium Immobilization And Mobilization By Soil Organic Matter, Peter H. Santschi, Kathleen A. Schwehr, Chen Xu, Matthew Athon, Yi-Fang Ho, Patrick G. Hatcher, Nicole Didonato, Daniel I. Kaplan

Chemistry & Biochemistry Faculty Publications

The human and environmental risks associated with Pu disposal, remediation, and nuclear accidents scenarios stems mainly from the very long half-lives of several of its isotopes. The SRS, holding one-third of the nation’s Pu inventory, has a long-term stewardship commitment to investigation of Pu behavior in the groundwater and downgradient vast wetlands. Pu is believed to be essentially immobile due to its low solubility and high particle reactivity to mineral phase or natural organic matter (NOM). For example, in sediments collected from a region of SRS, close to a wetland and a groundwater plume, 239,240Pu concentrations suggest immobilization by NOM …

Investigation Of 89zr-Siderophores As Molecular Imaging Agents For Positron Emission Tomography Imaging Of Bacterial Infections, Nora C. M. Goscinski

Arts & Sciences Electronic Theses and Dissertations

Siderophores are small molecules synthesized by bacteria to harvest Fe³⁺ from their environment. In infection scenarios, their production can increase infection virulence by increasing the ability of bacteria to obtain Fe³⁺ and therefore grow more rapidly. The selective uptake of siderophores in vivo in multi-bacteria environments indicates that this class of molecules has a potential use as selective imaging agents. In this work, DFO-NCS and a library of trihydroxamate siderophores were evaluated as vehicles to deliver ⁸⁹Zr selectively to bacteria for Positron Emission Tomography (PET) imaging of bacterial infections.

Productive work with radiometals involves thorough knowledge of …

Uses Of Diaryliodonium Salts And Methods For Their Synthesis, Jordan M. Veness

Department of Chemistry: Dissertations, Theses, and Student Research

Diaryliodonium salts have been studied continuously since the first report of their synthesis in 1894. Diaryliodonium salts are I(III) derivatives that are air- and moisturestable. The reactivity of these compounds resembles the organometallic chemistry of heavy transition metal ions such as Pb(IV), Hg(II), Th(III), and Pd(II). A significant advantage of diaryliodonium salts is that they can carry undergo many of the aryl functionalization reactions of heavy metal organometallic complexes, yet they have little to no toxicity and they are relatively inexpensive to prepare. The DiMagno laboratory uses diaryliodonium salts as precursors in the final synthetic step of radiopharmaceuticals; given that …

Exploring Rapid Radiochemical Separations At The University Of Tennessee Radiochemistry Center Of Excellence, Howard L. Hall, John D. Auxier Ii

Faculty Publications and Other Works -- Institute for Nuclear Security

The University of Tennessee formed its Radiochemistry Center of Excellence (RCoE) in 2013 with support from the U.S. National Nuclear Security Administration. One of the major thrusts of the RCoE is to develop deeper understanding of rapid methods for radiochemical separations that are relevant to both general radiochemical analyses as well as post-detonation nuclear forensics. Early work has included the development and demonstration of rapid separations of lanthanide elements in the gas phase, development of a gas-phase separation front-end for ICP-TOF-MS analysis, and the development of realistic analytical surrogates for post-detonation debris to support methods development.

The Development Of Cyclic Rgd Peptides Stabilized Through 99mtc/Re(Co)3+, Aagam Patel

Electronic Thesis and Dissertation Repository

Protein secondary structure can be mimicked by incorporating structural constraints into peptides and this can be facilitated by metal coordination. The objective of this project is to establish a chelation system with a cancer targeting peptide sequence, where the coordination to a metal centre results in a cyclic metallopeptide. Cyclic RGD peptides are antagonists for α_vβ₃ and other integrins, which are present during tumour angiogenesis. Arg-Gly-Asp (RGD) sequence is employed in the peptide backbone, with an un-natural amino acid (3-Pal) and a chelating molecule (pyridyl-triazole, pyta) present on opposite ends of the peptide sequence to form a …

Laser Ablation Icp-Ms Of Actinide Oxides As Simulated Used Nuclear Fuels, Keri Campbell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ability to examine elemental and isotopic ratios of fuels, waste forms, and other solids by direct analysis using laser ablation techniques can greatly reduce analysis costs and time. This is particularly true for actinide elements, as they contain useful information of the fuel cycle and nuclear forensics. Current methods to evaluate the composition of used fuel include a lengthy process of digestion, separations and often require multiple techniques and sample preparations to determine the elemental and isotopic composition. Furthermore all spatial information is lost during the digestion process, eliminating potentially useful data for detailed analysis. The goal of this …

Advances In High-Throughput Analysis: Automated Radiochemical Separations And Nanopillar Based Separations And Field Enhanced Spectroscopy, Jennifer Jeanne Charlton

Doctoral Dissertations

Often the need to analyze a large number of samples coincide with critical time consternates. At such times, the implementation of high-throughput technologies is paramount. In this work we explore some viable pathways for high-throughput analysis and develop advancements in novel forms of detection of materials that are vital in the environmental, biological as well as national security arenas. Through the use of new protocols with high sensitivity and specificity as well as simplified chemical processing and sample preparation we aim to allow for improved throughput, fieldable detection, and rapid data acquisition of extensive sample sets. The methods developed in …

Student Writing Competition

International Journal of Nuclear Security

No abstract provided.

Impurity Diffusion As A Possible Metal Chronometer For Pre-Detonation Nuclear Forensics, Edward T. Peskie, Howard L. Hall

International Journal of Nuclear Security

The ability to determine the age of seized nuclear material—that is, the time that has passed since it was formed— would provide crucial data to be used in its investigation. This paper reviews the methods and mathematical reasoning behind the use of diffusion theory, as previously applied to analysis of metals in ancient artifacts and other objects, to modern investigations in nuclear science. We here examine the time-dependent processes of diffusion, including grain boundary diffusion and discontinuous precipitation, and we assess the utility of examining the profiles of impurity and alloying element concentrations for use as a tool in pre-detonation …

Masthead

International Journal of Nuclear Security

No abstract provided.