Radiochemistry Commons^™

Synthesis And Thermodynamic Analysis Of Volatile Beta-Diketone Complexes Of Select Lanthanides Via Gas-Phase Separations, Daniel Hanson

Doctoral Dissertations

Rapid separation techniques for fission and activation products have long been desired to supplant the slow solution-based methodologies currently used. In this work, rare earth elements were derivatized with β [beta]-diketones to synthesize rare earth complexes with high volatility suitable for gas-phase separations. Rare earth elements samarium and dysprosium were combined with hfac (1,1,1,5,5,5-hexafluoro-2,4-pentadione) and fod (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione) and analyzed using a gas-phase separation technique. Rare earth elements praseodymium and europium were combined with dpm (2,2,6,6-tetra-methyl-3,5-heptanedione) and similarly analyzed. Employing the data from the separations, the entropy (Δ [delta] S) and enthalpy (Δ [delta] H) of adsorption were evaluated mathematically based …

Simultaneous Determination Of Multiple Actinide Elements In A Variety Of Soils Utilizing A Standardized Sequential Extraction Protocol, Sherry Alina Faye

UNLV Theses, Dissertations, Professional Papers, and Capstones

To obtain a better understanding of the mobility of actinide element contaminants in the environment, the association of the contaminants with specific host phases of soils and sediments must be investigated. This investigation is most commonly conducted using sequential extraction techniques that employ the selective dissolution of soil phases with increasingly aggressive chemical treatment. Though several sequential extraction studies exist in literature, conclusions cannot be made by direct comparison of data due to the lack of uniformity in the protocols used. This work aims to continue development of a standard sequential extraction protocol and expanding its capabilities to include the …

Technetium Sulfide: Fundamental Chemistry For Waste Storage Form's Application, Maryline Ghislaine Ferrier

UNLV Theses, Dissertations, Professional Papers, and Capstones

Technetium is the lightest radioelement. The isotope ⁹⁹Tc has around a 6% yield from ²³⁵U with a half-life of 2.13 x 10⁵ years. The high mobility of TcO₄^-, the common chemical form of technetium in the environment makes ⁹⁹Tc an isotope of concern in nuclear waste management. Despite its important role in radiopharmaceuticals and in the nuclear fuel cycle, the fundamental chemistry of technetium is not as well developed as that of the neighboring transition metals; one of the most striking examples being its sulfide chemistry.

Only two technetium binary sulfide compounds had …

Synthesis And Characterization Of Ln[Hfac]X And Ln[Fod]X Complexes For Thermochromatographic Separations, Matthew L. Marsh

Chancellor’s Honors Program Projects

No abstract provided.

Effect Of Gamma Radiation On The Interfacial Reactions And Transfer Processes Of Phosphonium-Based Ionic Liquids With Carbon Steel, Ryan P. Morco

Electronic Thesis and Dissertation Repository

This thesis presents work on the effects of ionizing radiation on phosphonium-based ionic liquids (ILs). Ionic liquids are known for their tunable properties which make them attractive options for applications for the separation and sequestration of metal ions from spent nuclear fuels, and candidate lubricants for systems under severe conditions. The high radiation environment found in spent fuel processing may decompose the solvents (ILs) used in the process and affect their separation efficiency. The radiolytic decomposition products can also alter the physical and chemical properties of an IL in ways which can affect the potential corrosion of metal alloys in …

Resin-Supported Arylstannanes As Precursors For Radiolabeling With Iodine: Benzaldehydes, Benzoic Acids, Benzamides, And Nhs Esters, Mustafa Janabi, Catherine M. Pollock, Ann-Marie Chacko, Duncan H. Hunter

Chemistry Publications

A highly cross-linked polystyrene resin bearing a reactive chlorostannane moiety 1 has been used to generate a variety of arylstannane radiopharmaceutical precursors for no-carrier-added radioiodination. The resins were characterized for their solvent compatibility and sensitivity to acid cleavage. Resin-supported arylstannanes synthesized via their aryl lithium analogues include 3- and 4-stannylbenzaldehydes, 3- and 4-stannylbenzoic acids, and 3- and 4-N-succinimidyl benzoates. A three-step route to the resin-supported stannylbenzoic acids 12a/b was developed through resin-supported benzaldehydes 11a/b. The aldehyde to acid conversion efficiency is >90%, and acid loading capacities of 0.66–0.94 mmol/g were obtained. Resin-supported N-succinimidyl benzoates 16a/b …

The Development Of Metal-Organic Compounds For Use As Molecular Imaging Agents, Emily J. Simpson

Electronic Thesis and Dissertation Repository

Molecular imaging probes allow for the non-invasive diagnosis of many diseases through the use of a targeting entity for site specific delivery, as well as a signal for external visualization of probe accumulation in the body. This thesis will focus on the development of new approaches to synthesize targeting peptides and chelators for radionuclide incorporation towards the design of novel molecular imaging probes.

Histidine is a tridentate chelator that can be attached in a pendant fashion to a biomolecule in order to coordinate technetium-99m. Once coordinated, it forms a neutral complex that is capable of forming diastereomers with inverted stereochemistry …

Development Of A Gallium-Containing One-Bead One-Compound Peptide Library For The Discovery Of New Molecular Imaging Probes, Fernanda C. Bononi

Electronic Thesis and Dissertation Repository

An eight amino acid one-bead one-compound (OBOC) peptide library, containing a gallium-DOTA complex, was developed in an attempt to overcome common issues associated with the later addition of radionuclides to peptide chains of imaging probes. The further addition of a radionuclide often changes the binding properties of a peptide, as it adds bulk, and possibly charges. MALDI (matrix-assisted laser desorption ionization) tandem mass spectrometry was determined to be the method of choice in order to deconvolute gallium-containing peptide sequences. The library obtained was screened against the breast cancer cell lines MDA-MB-231 and MCF-7. Positive beads were isolated and sequences were …

Thin Films Cds/Cdte Diodes For Nuclear Radiation Detection, Julianna Calkins, John Murphy, Lindsey Smith, Israel Mejia, Bruce Gnade, Manuel Quevedo-Lopez

Undergraduate Research Conference

No abstract provided.

Speciation Behavior Of Americium Higher Oxidation States For The Separation Of Americium From Curium, Catherine Lynn Riddle

UNLV Theses, Dissertations, Professional Papers, and Capstones

Several countries are currently expanding the use of nuclear energy as a method for the safe generation of carbon free energy and a number are evaluating starting up a nuclear power program. Closed fuel cycle technologies may be key to waste reduction and a sustainable nuclear energy future and to support the development of more efficient fuel cycles, the investigation of the chemical properties of key actinides is at the forefront of separations research. In this work the characterization of higher oxidation states of americium (Am) has been performed using spectroscopic methods. Americium in the formal oxidation state of Am(V) …

Syntheses Of Precursors To Fluorine-18 Labeled Pet Imaging Agents, Lindsay B. Boling

Chancellor’s Honors Program Projects

No abstract provided.

Binary Technetium Halides, Erik Vaughan Johnstone

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this work, the synthetic and coordination chemistry as well as the physico-chemical properties of binary technetium (Tc) chlorides, bromides, and iodides were investigated. Resulting from these studies was the discovery of five new binary Tc halide phases: α/β-TcCl₃, α/β-TcCl₂, and TcI₃, and the reinvestigation of the chemistries of TcBr₃ and TcX₄ (X = Cl, Br). Prior to 2009, the chemistry of binary Tc halides was poorly studied and defined by only three compounds, i.e., TcF₆, TcF₅, and TcCl₄. Today, ten phases are known (i.e., TcF …

Characterization And Optimization Of Extraction Chromatography Resins For Rapid Separations For Safeguard And Nuclear Forensics Purposes, Audrey Roman

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this work, extraction chromatography resins, DGA and UTEVA, were characterized under various conditions in order to identify novel rapid separations for safeguards and nuclear forensic purposes. For safeguards purposes, mixed matrices containing some of the largest components found in used fuel and either Am, Pu, or U were characterized on DGA and UTEVA resins in order to determine any effects from the addition of these constituents. Results indicated that 5 M HNO₃ would be an optimal loading condition due to the consistent actinide adsorption in the presence of the additional used fuel components. Investigations of varying the anion …

Radiopharmaceuticals: The Application Of Technetium-99m And Rhenium Complexes, Angela Kristin Binion

Honors Capstone Projects - All

Nuclear imaging used in diagnostic medicine requires the use of radiopharmaceuticals to make biological areas visible under a gamma camera. Although much success has been found in the use of technetium based imaging agents, their corresponding rhenium complexes can provide insight into the chemical properties of these radiopharmaceuticals without the potentially damaging effects of radiation. Technetium and rhenium complexes utilize a bifunctional chelator to act as a linker between biological vectors and the metal, improving the coordination between the two. Ligands containing thiazole rings have been successfully coordinated to technetium or rhenium tricarbonyl complexes, although it is uncertain whether coordination …

The Electrochemistry Of Hydrogen Peroxide On Uranium Dioxide And The Modelling Of Used Nuclear Fuel Corrosion Under Permanent Disposal Conditions, Linda Wu

Electronic Thesis and Dissertation Repository

This thesis reports a series of investigations examining the corrosion process of used nuclear fuel under permanent disposal conditions. The motivation of the project is that the safety assessment of deep geological disposal of spent nuclear fuel requires a fundamental understanding of the processes controlling fuel corrosion which could lead to the release of radionuclides to the geosphere from a failed container.

One primary objective of this project was to develop a computational model in order to simulate fuel corrosion under the disposal conditions. A series of simulations based on COMSOL were designed and developed to determine the influence of …

Peptidomimetic Ghs-R1a Agonists As Pet Imaging Agents For Prostate Cancer, Milan M. Fowkes

Electronic Thesis and Dissertation Repository

Contemporary diagnostic techniques for prostate cancer (PCa) have a limited ability to distinguish between benign and malignant disease. The ghrelin receptor has a differential expression in normal, benign and cancerous prostatic tissue. Targeting this receptor with 18F-radiolabelled peptidomimetics would enable differentiation between these disease states via PET imaging. A series of 19F-peptidomimetics were synthesized and characterized by HRMS, HPLC and 1 H-NMR spectroscopy in order to test locations for 18F radioisotope insertion. Competitive receptor binding assays using HEK293/GHS-R1a cells were used to evaluate compound binding affinities. This led to the identification of two lead compounds: [1-Nal4,Lys5(4-FB)]G-7039 (IC50 = 69 nM) …

Nuclear Structure In Transitional Regions: Studies Of ¹³²,¹³⁴Xe And Lifetimes In The Stable Zr Nuclei With The (N,N′Γ) Reaction, Erin Elizabeth Peters

Theses and Dissertations--Chemistry

Nuclei at closed shells tend to be spherical and are well-described by the shell model, while those between closed shells are deformed and better described by collective models. The nuclei which are in transitional regions between spherical and deformed may be studied to gain insight into the nature of this transition. The stable isotopes of zirconium and xenon span such transitional regions and are the subject of this dissertation. Gamma-ray spectroscopy following inelastic neutron scattering has been performed on the stable isotopes of Zr as well as ^132,134Xe at the University of Kentucky Accelerator Laboratory. Level lifetimes have been …