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Articles 1 - 30 of 619
Full-Text Articles in Chemistry
Studies Directed Toward The Synthesis Of Amphibian Alkaloids Via Iridium Catalyzed N-Heterocyclization Reactions, Kiran Kumar Thota
Studies Directed Toward The Synthesis Of Amphibian Alkaloids Via Iridium Catalyzed N-Heterocyclization Reactions, Kiran Kumar Thota
University of New Orleans Theses and Dissertations
The pyrrolidine and piperidine ring systems are present in a variety of different classes of amphibian alkaloids. We have found the iridium catalyzed N-heterocylization reaction of diols with amines to be very useful for the construction of novel pyrrolidine, piperidine and piperazine derivatives. The scope and utility of the iridium catalyzed N-heterocyclization reaction for the construction of novel anuran scaffolds using amino diols and triols are presented. Studies directed towards the total synthesis of 4,6-disubstituted quinolizidine and (±)-epiquinamide are discussed.
The second study is focused on the selective conversion of terminal dienes to primary diols. This conversion has always had …
Incorporation Of Charge Transfer Into Classical Molecular Dynamics Force Fields With Applications In Physical Chemistry., Marielle Soniat
Incorporation Of Charge Transfer Into Classical Molecular Dynamics Force Fields With Applications In Physical Chemistry., Marielle Soniat
University of New Orleans Theses and Dissertations
The presence of charge transfer (CT) interactions is clear in a variety of systems. In CT, some electron density is shifted from one molecule to another (non-bonded) molecule. The importance of this CT interaction is unclear. Previous attempts to look at the conse- quences of CT required the use of ab initio molecular dynamics (AIMD), a computationally intensive method. Herein, a method for including CT in force field (FF) simulations is described. It is efficient, produces charges in agreement with AIMD, and prevents long- ranged CT.
This CT MD method has been applied to monatomic ions in water. When solvated, …
Template-Assisted Fabrication Of Ferromagnetic Nanomaterials, Jagnyaseni Tripathy
Template-Assisted Fabrication Of Ferromagnetic Nanomaterials, Jagnyaseni Tripathy
University of New Orleans Theses and Dissertations
Abstract
Template assisted deposition was used to produce various nanomaterials including simple nanowires, nanorods, multi-segmented metal nanowires, core-shell nanowires, alloy and polymer wires and tubes. Anodized aluminum oxide (AAO) membranes were used as templates for the growth of the various structures using an electrochemical deposition method and also by wetting the porous templates. In the electrochemical deposition method, the pore size of the templates affects the rate of synthesis and the structures of the nanomaterials while in the wetting method, the viscosity and reaction time in the polymer solution influence the structures of the nanomaterials.
A conventional two-step anodization procedure …
Production And Applications Of Formaldehyde-Free Phenolic Resins Using 5-Hydroxymethylfurfural Derived From Glucose In-Situ, Yongsheng Zhang
Production And Applications Of Formaldehyde-Free Phenolic Resins Using 5-Hydroxymethylfurfural Derived From Glucose In-Situ, Yongsheng Zhang
Electronic Thesis and Dissertation Repository
The phenol-formaldehyde (PF) resin manufacturing industry is facing a growing challenge with respect to concerns over human health, due to the use of carcinogenic formaldehyde and sustainability due to the use of petroleum-based phenol in PF resin manufacture. Glucose and its derivative, 5-hydroxymethylfurfural (5-HMF), have proven to be potential substitutes for formaldehyde in the synthesis of phenolic novolac resins.
This thesis investigated a number of glucose and 5-HMF resin systems including the curing of phenol-glucose novolac resin (PG) with a bis-phenol-A type epoxy. The curing process was modeled according to the Sestak-Berggren equation (S, B) using Málek methods. This was …
The Effect Of Ph And Counterion On The Size Distribution And Luminescence Lifetime Of Terbium-Doped Lanthanum Nanocrystals, Sarah Baker
Undergraduate Honors Theses
In recent years, nanoparticles have been applied to and have gained prevalence in fields such as chemistry, biology, the medical sciences, and biotechnology,and have attracted the attention of medical researchers as potential microscopic drug delivery systems in the human body. In particular, nanoparticles made with the lanthanides have shown themselves to be useful to many biological applications due to their unique luminescent properties. It is crucial to determine optimum synthetic parameters so that nanoparticles are both small enough to pass through the kidneys and also have the ability to attach different functional groups so that they may be relevant to …
Surface Functionalization Of Inorganic Substrates With Polymeric Ligands Using Raft Polymerization, Anand Viswanath
Surface Functionalization Of Inorganic Substrates With Polymeric Ligands Using Raft Polymerization, Anand Viswanath
Theses and Dissertations
This work focused on using polymers to modify the surface of various inorganic substrates, ranging from TiO2, ITO, CDSe and CdS nanostructures to micron sized silica particles. The synthesis of the polymers using the RAFT technique and the characterization of the functionalized substrates were analyzed in detail to provide insights into their use for various applications. In the first part of this work, novel phosphate based RAFT agents and phosphate containing polymers, including poly(methyl methacrylate) (PMMA), poly(glycidyl methacrylate) (PGMA) and poly(dimethyl siloxane) (PDMS) were synthesized. Alkyne functionalized PGMA was used to click to ITO surfaces in a grafting-to method, and …
Universal Two-Electron Correlation Operator On Excited States, Bryan Thomas Nichols
Universal Two-Electron Correlation Operator On Excited States, Bryan Thomas Nichols
Theses and Dissertations
Excited states of chemical systems are extremely important in understanding spectra, chemical phenomena, as well as how a particular compound behaves in reactions. Computationally, excited states are normally very expensive to calculate. The difficulty in calculating these states with wavefunction based methods can be mainly attributed to the calculation of large multi-determinant wavefunctions. One reason to use a complicated multi-determinant wavefunction is to include some of the effects of correlation energy. The quantity of correlation energy can most simply be defined as the reduction in energy caused by any two or more electrons trying to avoid each other. The most …
Polyglyoxylates: A New Class Of Triggerable Self-Immolative Polymers, Bo Fan
Polyglyoxylates: A New Class Of Triggerable Self-Immolative Polymers, Bo Fan
Electronic Thesis and Dissertation Repository
Self-immolative polymers, which degrade by an end-to-end depolymerization mechanism in response to the cleavage of a stabilizing end-cap from the polymer terminus, are of increasing interest for a wide variety of applications ranging from sensors to controlled release. However, the preparation of these materials often requires expensive, multi-step monomer syntheses and the degradation products such as quinone methides or phthalaldehydes are potentially toxic to humans and the environment. We demonstrate here that polyglyxoylates can serve as a new and versatile class of self-immolative polymers. Polymerization of the commercially available monomer ethyl glyoxylate, followed by end-capping with a 6-nitroveratryl carbonate provides …
Cationic Metallocene-Containing Polymers: From Synthesis To Applications, Jiuyang Zhang
Cationic Metallocene-Containing Polymers: From Synthesis To Applications, Jiuyang Zhang
Theses and Dissertations
Metallopolymers, with the combination of metals and polymeric framworks, have attracted a lot of attention during the past decades. The development of metallopolymers has been largely driven by the desire to combine the synthetic efficiency and versatility of an organic polymer framework with the unique redox, responsive and catalytic properties of inorganic metals. Among different kinds of metallopolymers, metallocene-containing polymers, have been widely utilized for applications ranging from electrochemical sensors to templates for advanced inorganic catalysts to battery materials, due to their unique physicochemical properties. In the first part of my thesis, we showed controlled/living polymerization strategies to prepare well-defined …
Toward The Combinatorial Development Of Hydrophobic-Tagged Antifolate-Directed Degradation Of Human Thymidylate Synthase, Daniel J. Menasco
Toward The Combinatorial Development Of Hydrophobic-Tagged Antifolate-Directed Degradation Of Human Thymidylate Synthase, Daniel J. Menasco
Theses and Dissertations
Direct post-translational control over a protein of interest (POI) can be exploited by manipulating the cells protein quality-control systems responsible for either intracellular turnover through ubiquitination (POI half-life) or repairing and degrading misfolded proteins.1 In an effort to target and degrade a high value POI we selected the enzyme human thymidylate synthase (TS) for post-translational degradation through ligand-directed ubiquitination and hydrophobic tagging. Thymidylate synthase catalyzes the reductive methylation of 2’-deoxyuridine monophosphate (dUMP) to 2’-deoxythymidine monophosphate (dTMP). As the de novo source of dTMP the regulation of intracellular TS is strictly controlled by ubiquitinindependent proteasomal degradation mediated by an internal TS-degron …
Synthesis And Characterization Of Pbs Quantum Sheets Through Lamellar Assembly, And Updates To The Cdse Quantum Wire Synthesis, Paul James Morrison
Synthesis And Characterization Of Pbs Quantum Sheets Through Lamellar Assembly, And Updates To The Cdse Quantum Wire Synthesis, Paul James Morrison
Arts & Sciences Electronic Theses and Dissertations
This dissertation reports the novel synthesis of PbS quantum plates (QPs) via a reaction executed at low temperatures. The PbS QPs are grown in a template-assisted mechanism, with the first excitonic peak observed in the visible region of light at ~620 nm (2.0 eV), at an energy radically different than the band gap of bulk PbS (~3000 nm, 0.42eV). The large energy shift is due to the extremely thin dimension of these nanoplates, which is determined to be ~1 nm in thickness. Thickness measurements are made in a powder X-ray diffractometer (XRD) at low angles (between 2-15º 2θ). These measurements …
Polyol Synthesis Of Silver Nanowires By Heterogeneous Nucleation And Mechanistic Aspects Influencing Its Length And Diameter, Waynie M. Schuette
Polyol Synthesis Of Silver Nanowires By Heterogeneous Nucleation And Mechanistic Aspects Influencing Its Length And Diameter, Waynie M. Schuette
Arts & Sciences Electronic Theses and Dissertations
Various additives are employed in the polyol synthesis of silver nanowires (Ag NWs), which are typically halide salts such as NaCl. A variety of mechanistic roles have been suggested for these additives. My research showed that the early addition of NaCl in the polyol synthesis of Ag NWs from AgNO3 in ethylene glycol results in the rapid formation of AgCl nanocubes, which induce the heterogeneous nucleation of metallic Ag upon their surfaces. Ag NWs subsequently grow from these nucleation sites. The conclusions are supported by studies using ex-situ generated AgCl nanocubes.
Additionally, the final mean silver nanowire diameter is found …
Study Of Ii-Vi Colloidal Semiconductor Magic-Size Nanoclusters And Crystalline Quantum Platelets, Yuanyuan Wang
Study Of Ii-Vi Colloidal Semiconductor Magic-Size Nanoclusters And Crystalline Quantum Platelets, Yuanyuan Wang
Arts & Sciences Electronic Theses and Dissertations
The main objective of this project is to prepare and isolate the smallest, discrete, magic-size nanoclusters of cadmium selenide (CdSe) and to grow crystalline, wurtzite CdSe quantum platelets (QPs) at room temperature. The achievement of these goals enables us to provide a general synthesis of II-VI semiconductor magic-size nanoclusters and low-temperature routes to well-passivated nanocrystals having a range of compositions and morphologies.
The magic-size nanocluster (CdSe)13 is grown in a lamellar-bilayer soft template at room temperature. The results described in this thesis strongly suggest that [(CdSe)13(n-octylamine)13] is the most thermodynamically stable nanocluster and serves as a key intermediate in the …
Isotope Harvesting At Heavy-Ion Fragmentation Facilities, Tara Elise Mastren
Isotope Harvesting At Heavy-Ion Fragmentation Facilities, Tara Elise Mastren
Arts & Sciences Electronic Theses and Dissertations
Isotope harvesting from heavy-ion fragmentation facilities is a potential source of isotopes of interest for applications research. With the upgrade of the National Superconducting Cyclotron Laboratory (NSCL) to the Facility for Rare Isotope Beams (FRIB) usable quantities of many isotopes of interest will be produced and available for harvest from an aqueous beam dump. If available, these isotopes would be of interest to a broad range of applications such as medicine, geology, and stockpile stewardship. Preliminary experiments were performed at the NSCL in order to determine the feasibility of isotope harvesting at (FRIB).
A water target station that consisted of …
Kinetic Analysis And Inhibition Studies Of Iron-Dependent Histone Demethylases, Barbara Gordon Cascella
Kinetic Analysis And Inhibition Studies Of Iron-Dependent Histone Demethylases, Barbara Gordon Cascella
Arts & Sciences Electronic Theses and Dissertations
The research presented herein focuses on the kinetics and inhibition of the KDM4 subfamily of Jumonji C (JmjC) domain-containing histone demethylases (HDMs). Belonging to the larger class of alpha-ketoglutarate (alpha-KG)-dependent, non-heme iron monooxygenases, the JmjC-HDMs remove methyl groups from mono-, di-, and tri-methylated histone lysine residues through an Fe(IV)-oxo-catalyzed hydroxylation reaction. JmjC-HDMs have been found to play integral roles in the maintenance of genomic integrity as well as in the regulation of transcription. Three KDM4 members were studied: the mixed H3K9/H3K36 demethylases KDM4A and KDM4C, and the pure H3K9 demethylase KDM4E. KDM4C is a hypoxia-inducible factor 1 (HIF-1) target gene …
Colloidal And Biological Properties Of Triscationic Amphiphiles With One Or Two Tails, John N. Marafino
Colloidal And Biological Properties Of Triscationic Amphiphiles With One Or Two Tails, John N. Marafino
Masters Theses, 2010-2019
The decline in the development of novel antimicrobials, combined with the misusage and over prescription of antibiotics, has contributed to the increasing prevalence of antimicrobial-resistant infections. Thus development of effective novel disinfectants could reduce the transmission of pathogens and decrease the risk of infection by antibiotic resistant organisms. The antimicrobial activity of amphiphiles, compounds with hydrophobic and hydrophilic regions, was first reported in 1935, and has influenced the synthesis of amphiphiles with variations in structure. In this study, three series of amphiphiles were synthesized by two subsequent Menshutkin reactions. Each amphiphile contains one or two hydrocarbon tails ranging from 8 …
Exploring The Reactivity Of Donor-Acceptor Cyclopropanes And The Synthesis Of (+/-)-Quebrachamine, Huck K. Grover
Exploring The Reactivity Of Donor-Acceptor Cyclopropanes And The Synthesis Of (+/-)-Quebrachamine, Huck K. Grover
Electronic Thesis and Dissertation Repository
The development and utility of cyclopropanes is an ever-growing field within organic chemistry. In particular, donor-acceptor cyclopropanes have been used in a vast array of methods to access a variety of different hetero and carbocyclic molecular scaffolds. Recently, we have developed a Zn(NTf2)2 catalyzed tandem reaction consisting of a nucleophilic ringopening of 1,1-cyclopropanediesters by 2-alkynyl indoles followed by a Conia-ene ring closure, resulting in the efficient one-step synthesis of tetrahydrocarbazoles. These adducts may be further elaborated to carbazoles. The scope and limitations of this method were determined along with a mechanistic study into the function of the zinc catalyst. In …
New 4-Aminoquinoline Compounds To Reverse Drug Resistance In P. Falciparum Malaria, And A Survey Of Early European Antimalarial Treatments, Katherine May Liebman
New 4-Aminoquinoline Compounds To Reverse Drug Resistance In P. Falciparum Malaria, And A Survey Of Early European Antimalarial Treatments, Katherine May Liebman
Dissertations and Theses
Intermittent fevers caused by Plasmodium parasites have been known for millennia, and have caused untold human suffering. Today, millions of people are afflicted by malaria each year, and hundreds of thousands die. Historically, the most successful synthetic antimalarial drug was chloroquine, as it was safe, inexpensive, and highly efficacious. However, plasmodial resistance to chloroquine now greatly limits its utility. Previously in our laboratories it has been shown that attachment of a "reversal agent moiety" to the side chain of chloroquine can result in the restoration of activity against chloroquine-resistant strains of P. falciparum malaria. In the first part of the …
Electrochemical Synthesis Of Nanostructured Noble Metal Films For Biosensing, Jay Kishan Bhattarai
Electrochemical Synthesis Of Nanostructured Noble Metal Films For Biosensing, Jay Kishan Bhattarai
Dissertations
Nanostructures of noble metals (Au and Ag) are of interest because of their important intrinsic properties. Noble metals by themselves are conductive, physically robust, chemically inert, and strongly bind to thiols. However, when the nanostructures are formed, they in addition possess high surface area and unique optical properties tunable by adjusting the shape and size. All of these properties make nanostructures of noble metals suitable candidates to be used as a transducer for biosensing. Individual nanostructures might be easier to prepare but difficult to handle to be used as a transducer. Therefore, we prepared and analyzed nanostructured films/coating of noble …
Bidentate Ferrocenyl-Dithiol Reagents For Nanocluster Surface Functionalization, Yiyi Liu
Bidentate Ferrocenyl-Dithiol Reagents For Nanocluster Surface Functionalization, Yiyi Liu
Electronic Thesis and Dissertation Repository
Previous work using monodentate ferrocenyl-chalcogen reagents for nanocluster surface functionalization has indicated an effective way to involve ferrocene moieties onto the surface of these frameworks. However, the abilities of the large polynuclear nanocluster with ferrocene rich surface to form crystalline materials suitable for single crystal X-ray analysis proved to be limited. New bidentate ferrocenyl-chalcogen reagents have been synthesized and characterized in order to probe their ability in this case.
The preparation of new bidentate ferrocenyl chalcogen reagents 1,1’-fc(C{O}OCH2CH2SH)2 (fc = ferrocenyl) and 1,1’-fc(C{O}NHCH2CH2SH)2 are presented. Furthermore, the preparation of silylated …
Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa
Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa
Electronic Thesis and Dissertation Repository
The objective of this research was to develop polymeric nanoparticles (NPs) having improved drug release properties for drug delivery. Poly(ester amide)s (PEAs) are promising biodegradable polymers. PEA NPs were prepared via emulsification-evaporation and salting-out methods and optimized through by varying different processing parameters. Polymer-model drug conjugates based on PEAs containing L-aspartic acid and rhodamine B were synthesized and used for NP preparation. Release behavior was studied and compared to a control system with physically encapsulated rhodamine B. It was shown that the release of rhodamine B from the covalent system did not show the burst effect and exhibited a slower …
Scale-Up Methodology For Bench-Scale Slurry Photocatalytic Reactors Using Combined Irradiation And Kinetic Modelling, Patricio J. Valades Pelayo
Scale-Up Methodology For Bench-Scale Slurry Photocatalytic Reactors Using Combined Irradiation And Kinetic Modelling, Patricio J. Valades Pelayo
Electronic Thesis and Dissertation Repository
The present study focuses on developing a predictive methodology to scale-up a slurry annular photoreactor using a TiO2 Degussa P25 from the bench-scale to a pilot-plant scale. The bench-scale photoreactor is a Photo-CREC-Water II, a 2.65 L internally-irradiated slurry annular photocatalytic reactor. The pilot-plant scale photoreactor is a Photo-CREC Water Solar Simulator, a 9.8 L pilot-plant photoreactor, externally irradiated by eight lamps.
The adopted methodology allows the independent validation of radiative and kinetic models avoiding cross-correlation issues. The proposed approach involves two Monte Carlo methods, to model the Radiative Transfer Equation (RTE) inside each photoreactor. With this end, a …
Investigations Into Ambient Ionization Mechanisms: Electrospray Ionization And Direct Analysis In Real Time Mass Spectrometry, Stephen Colin Gibson
Investigations Into Ambient Ionization Mechanisms: Electrospray Ionization And Direct Analysis In Real Time Mass Spectrometry, Stephen Colin Gibson
Doctoral Dissertations
Mass spectrometry (MS) is an important tool for chemical analyses. Despite the MS requirement for generation of analyte gas-phase ions, many ion source designs afford little-to-no fragmentation, allowing characterization of intact molecules. However, this does not assure that detected ions are representative of the analytes’ natural state. Ionization mechanisms are generally complex and rarely fully understood. Fundamental research into these mechanisms provides greater insight into the relationship between solution chemistry and mass spectra. Work herein addresses aspects of two ambient ionization mechanisms: electrospray ionization (ESI) and Direct Analysis in Real Time (DART).
Ions produced by ESI are dispersed into a …
Synthesis And Thermodynamic Analysis Of Volatile Beta-Diketone Complexes Of Select Lanthanides Via Gas-Phase Separations, Daniel Hanson
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 …
Photo-Switchable Control Of Membrane Properties Of Liposomes And Biochemical Processes, Andrew Michael Bayer
Photo-Switchable Control Of Membrane Properties Of Liposomes And Biochemical Processes, Andrew Michael Bayer
Doctoral Dissertations
Liposomes are promising agents for drug delivery. They have the ability to encapsulate therapeutic drugs, resulting in decreased toxicity and prolonged circulation time. However, many obstacles to achieving broad utility in liposomal drug delivery still exist, including the ability to control release of therapeutic drugs and modulate surface reactivity. A primary focus of this dissertation involves the development of synthetic photocleavable lipids for controlled release from membranes.
Phosphatidylcholine (PC) is a natural lipid that comprises the majority of structural membranes. It contributes heavily to the formation of lipid bilayers in cell membranes, and modifications to the bilayer can induce membrane …
Computational Studies For Optimization And Design Of Extracting Agents For Separation Of Lanthanides And Actinides, Deborah Andrea Penchoff
Computational Studies For Optimization And Design Of Extracting Agents For Separation Of Lanthanides And Actinides, Deborah Andrea Penchoff
Doctoral Dissertations
Rare earths and actinides are of great interest given their varied applications in energy conversion and storage, such as in catalysis and batteries, and for advanced technological applications related to optical and magnetic properties (including electronics and automotive), amongst others. Many of the rare earth elements are considered endangered species due to their unique properties which have no clear alternatives that will maintain performance for important applications. The optimal approach is to find readily available alternatives for critical materials to ensure a certain standard of living and quality of life for future generations, but it is very likely that reusing …
Design And Implementation Of A Near-Field Scanning Optical Module For Inverted Microscopes, Taher Ababneh
Design And Implementation Of A Near-Field Scanning Optical Module For Inverted Microscopes, Taher Ababneh
Theses and Dissertations
This dissertation describes the design and implementation of a home-built near-field scanning optical microscope (NSOM) module for inverted microscopes. In this design, the NSOM module is built atop an inverted fluorescence microscope. This is particularly well suited for applications in which the normal imaging modes of the inverted microscope are still required to locate and study the sample before performing NSOM experiments. This module is used as a near-field instrument for nanostructure investigation of various samples including plane-ruled reflection gratings, AFM calibration standards, nanospheres and gold nanoparticles. In addition, we will demonstrate the ability to achieve nanometer-scale surface modification of …
Keeping In Touch: Exchange As An Adaptive Strategy In Southern Nevada, Timothy Joshua Ferguson
Keeping In Touch: Exchange As An Adaptive Strategy In Southern Nevada, Timothy Joshua Ferguson
UNLV Theses, Dissertations, Professional Papers, and Capstones
Archaeologists have always wondered about the extent of vessel movement in the American Southwest. Identifying vessel movement allows for the study of social interactions across a region and the role of ceramics in the adaptive processes of agriculturalists living in marginal, highly variable environments. In many instances, exchange may act as a way to reduce the risk of resource shortfalls by creating social ties in other areas. This research investigated the changing risk reduction strategies of households in the lowland Virgin region of southern Nevada by using geochemical methods to trace the exchange of locally produced pottery. It was hypothesized …
Simultaneous Determination Of Multiple Actinide Elements In A Variety Of Soils Utilizing A Standardized Sequential Extraction Protocol, Sherry Alina Faye
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
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 …