Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Hydrothermal (2)
- Alkali lanthanide fluoride (1)
- Aromatic compounds (1)
- Artificial minerals (1)
- BRINE (1)
-
- Bimetallic Co-Mo (1)
- Biological Monitoring (1)
- Biological monitoring (1)
- Biomonitoring (1)
- Birnessite (1)
- Buckybowls (1)
- CoMoS2 catalyst (1)
- Complex fluorides (1)
- Cryptomelane (1)
- Crystal Growth (1)
- Crystals (1)
- Curvature (1)
- Environmental monitoring (1)
- Fetal exposure (1)
- Fresnoite (1)
- Fullerenes (1)
- Functionalized nanoparticles (1)
- Human placenta (1)
- Hydrocarbons (1)
- Hydrodesulfurization (1)
- Hydrothermal synThesis (1)
- ICP-MS (1)
- ION EXCHANGE (1)
- Inorganic selenium compounds (1)
- Intramolecular effects (1)
Articles 1 - 13 of 13
Full-Text Articles in Chemistry
Manganese Oxide Mineral Phases Produced At Room Temperature Under Acidic Conditions Investigated With Xrd, Tem, Sem, Eds, And Bet, Nancy R. Birkner
Manganese Oxide Mineral Phases Produced At Room Temperature Under Acidic Conditions Investigated With Xrd, Tem, Sem, Eds, And Bet, Nancy R. Birkner
UNLV Theses, Dissertations, Professional Papers, and Capstones
This thesis concerns characterization of synthetic manganese oxides belonging to mineral phases known as Birnessite and Cryptomelane. Presented here are the results of an experiment designed to examine the influence of sodium, potassium, chloride, and sulfate ions on the reduction of potassium permanganate under acidic conditions at room temperature to produce Birnessite and Cryptomelane. The experiments used KMnO4 as the source of Mn and the resulting Birnessite and Cryptomelane precipitates were washed with 18 Mn/cm NANOpure water at the end of syntheses. Several state-of-the-art solid state techniques were used to characterize the Mn-based oxide mineral phases. Based on the literature …
Synthesis Of Complex Fluorides For Optical Applications, Seth Stepleton
Synthesis Of Complex Fluorides For Optical Applications, Seth Stepleton
All Dissertations
Large single crystals of alkali metal fluorides are desirable for many reasons. Fluoride laser crystals have a wide transmission range and on account of their low phonon energies, many efficient laser emissions have been obtained from 285 nm to 4.34 µm.1,2 Inorganic fluoride single crystals feature large bandgaps, very wide optical transmittance ranges from vacuum-ultraviolet (VUV) to mid-IR wavelength regions, lower refractive indices than those of oxides, and typically lower phonon energies (which drastically reduce multiphonon relaxation rates of rare earth ions).3
The main goal of this work was to investigate the hydrothermal synthesis of alkali metal fluorides. Melt techniques …
Understanding The Antioxidant Mechanism Of Inorganic Selenium, Oxo- Sulfur, And Polyphenol Compounds, And The Biological Implications Of Functionalized Nanoparticles, Ria Ramoutar
All Dissertations
Inorganic selenium, oxo-sulfur, and polyphenol compounds are found in foods and dietary supplements, and are recognized for their nutritional benefits and their potential to treat or prevent diseases caused by oxidative stress. In our experiments to determine the effects of inorganic selenium compounds on iron-mediated DNA damage, Na2SeO33 and SeO2 exhibit antioxidant and pro-oxidant activities depending on concentrations of both the compound and hydrogen peroxide. Additional experiments demonstrate that iron coordination is a novel mechanism responsible for the observed activities. In similar experiments, oxo-sulfur compounds prevent Cu+/ H2O2-mediated DNA damage significantly …
Synthesis And Characterization Of Magnetic Solids Containing Periodic Arrays Of Transition Metal Oxide Nanostructures, Wendy Queen
Synthesis And Characterization Of Magnetic Solids Containing Periodic Arrays Of Transition Metal Oxide Nanostructures, Wendy Queen
All Dissertations
The ultimate goal of the research presented in this dissertation was to explore new systems containing low–dimensional magnetic nanostructures in hopes of finding new extended solids exhibiting novel magnetic properties due to the confined magnetic lattices. The scope of this research is threefold: 1) to explore new solids containing low–dimensional magnetic nanostructures in the A–M–X–O system, where A is an alkali or alkalinendash;earth metal cation, M is a first–row transition metal cation, and X is P, As, or V, 2) to characterize these new materials and, through chemical substitution, fine tune (and optimize) magnetic and electronic properties of solids that …
Hydrothermal Crystal Growth Of Tetravalent And Pentavalent Metal Oxides, James Mann
Hydrothermal Crystal Growth Of Tetravalent And Pentavalent Metal Oxides, James Mann
All Dissertations
Over the past two hundred years synthetic growth of crystals has become vital to the technological advancement of our society. A variety of crystal growth techniques have been developed during this time, with each having its own nuances. These differences have enabled the growth of a wide spectrum of crystalline materials that can be used for many applications which include solid state lasers, semiconductors, and communication devices. Despite these techniques there are entire classes of materials which have thus far proved quite difficult to prepare as single crystals. In particular, crystal growth of the tetravalent and pentavalent metal oxides has …
Synthesis Of Ionic Liquid Monomers Using Fluorinated Sulfonyl Imide Anions And The 1,3-Dialkylimidazolium Cation, Thomas Hickman
Synthesis Of Ionic Liquid Monomers Using Fluorinated Sulfonyl Imide Anions And The 1,3-Dialkylimidazolium Cation, Thomas Hickman
All Dissertations
With their unique material and solvent properties, ionic liquids have seen an amazing, exponential increase in interest. After a brief introduction of select areas of interest for these compounds, this thesis mainly focuses on the development of novel polyfunctional ionic liquids and polymeric ionic liquids.
One of the preferred anions for ionic liquids is the bis((trifluoromethyl)sulfonyl) imide anion, first introduced by our group in 1982. It shows excellent thermal stability and the desired resonance delocalization of a negative charge for ionic liquids. A series of monofunctional, difunctional, and multi-functional bis(perfluoroalkylsufonyl)imides, along with 1,3-dialkylimidazolium cations were prepared by direct methylation of …
The Synthesis And Characterization Of Novel Microporous Hybrid Organic/Inorganic Materials, Kelly Whitenack
The Synthesis And Characterization Of Novel Microporous Hybrid Organic/Inorganic Materials, Kelly Whitenack
Honors Capstone Projects - All
Inorganic chemistry is essential to the formulation and improvement of modern materials such as catalysts, semiconductors, optical devices, super conductors, and advanced ceramic materials.1 New areas of inorganic chemistry are constantly being explored and new and often unusual inorganic compounds are constantly being synthesized and identified.1 Recently the field of inorganic chemistry has witnessed the synthesis and characterization of microporous metal organic framework compounds (MOFs). Microporous organic/inorganic materials have a wide range of physical properties as well as applications. The physical properties and applications drive the investigation into the synthesis and discovery of new and useful hybrid MOF …
Synthesis And Characterization Of Acetylenic Derivatives Of The Actinide Extractant (Aryl) N,N Di (Alkyl)Carbamoylmethylphosphine Oxide (Cmpo), Mario Ivan Baeza
Synthesis And Characterization Of Acetylenic Derivatives Of The Actinide Extractant (Aryl) N,N Di (Alkyl)Carbamoylmethylphosphine Oxide (Cmpo), Mario Ivan Baeza
Open Access Theses & Dissertations
We have used the reaction between the sodium salt of (diaryl)-N,N-di-(isobutyl)carbamoylmethylphosphine oxides {[Aryl)2P=O][iBu2NC=O]CH}-Na+ and chloromethylacetylenes to produce the first acetylenic derivatives of the carbamoylmethylphosphine oxide (CMPO) actinide extractants. The new compounds - CMPO-CH2C2H (1) {aryl = phenyl}, (2) {aryl = tBu-phenyl}; CMPO-CH2C2Me (3) {aryl = phenyl}; and CMPO-CH2C2CH2Cl (4) {aryl = phenyl}, (5) {aryl = tBu-phenyl} - have been characterized by spectroscopy (1H, 13C, 32P NMR) and also by single crystal X-ray diffraction. These new extractants lead the way to new derivatives aimed at using the materials as both optical and electrochemical actinide and other metal sensors.
Transition Metal Catalysts For Hydrodesulfurization Reactions Applied To Petroleum Industry, Brenda Torres
Transition Metal Catalysts For Hydrodesulfurization Reactions Applied To Petroleum Industry, Brenda Torres
Open Access Theses & Dissertations
Catalysis plays a fundamental role in petroleum refining and basic petrochemical industries creating new routes in the development of industrial processes. Moreover, catalysis has become indispensable to the solution of environmental pollution problems and therefore on public health. World wide concerns for preservation of the environment has motivated the development of "Green" catalyst based technologies, to achieve a better utilization of petroleum resources and demands for cleaner transportation fuels. These environmental concerns have led to increasingly drastic regulations on sulfur, nitrogen and aromatics content in fuels. Sulfur content in the motor and diesel fuels is continuously reduced by regulations to …
Computational Modeling Studies Of The Structures And Properties Of Organotin(Iv) And Stannyl-Thioether Systems With Comparisons To X-Ray Crystallography, Michelle R. Stem Joseph
Computational Modeling Studies Of The Structures And Properties Of Organotin(Iv) And Stannyl-Thioether Systems With Comparisons To X-Ray Crystallography, Michelle R. Stem Joseph
Open Access Theses & Dissertations
Controlling the toxic effects of organotin(IV) compounds involves engineering the structure of the molecules to optimize their properties. Molecular engineering, coupled with improved capabilities to generate reliable computational optimization models (COMs), will enable researchers to have greater success at harnessing the highly specific cytotoxicity of organotins. For example, as the thion ligand phenyl groups were replaced with Cl atoms, the S-Sn intramolecularity was strengthened, the bond distance decreased, and the stannyl tetrahedral structure was deformed from its triphenyl conformation. With each substitution, conformation deformations lowered the damaging bioactivity levels of thion. Bonding various ligands to organotin(IV) compounds …
Bowl-Shaped Polyaromatic Hydrocarbons (Buckybowls) : Crystal Packing And Metal Binding Reactions, Alexander S. Filatov
Bowl-Shaped Polyaromatic Hydrocarbons (Buckybowls) : Crystal Packing And Metal Binding Reactions, Alexander S. Filatov
Legacy Theses & Dissertations (2009 - 2024)
This work is a part of a broad program in our laboratory dedicated to the investigation of a new class of non-planar polyaromatic hydrocarbons that map onto the surfaces of fullerenes (and referred to as buckybowls). It focuses on the preparation of buckybowls, their molecular and solid state structures, and reactivity in metal binding reactions. For the first time, the structures of all available buckybowls have been analyzed using X-ray diffraction data collected in the course of this work, as well as data previously obtained in our group or reported by others (and dearchived from the Cambridge Structural Database). Forces …
Biomonitoring For Exposure To Trace Elements In Utero : Analysis Of The Human Placenta, Pamela Catherine Kruger
Biomonitoring For Exposure To Trace Elements In Utero : Analysis Of The Human Placenta, Pamela Catherine Kruger
Legacy Theses & Dissertations (2009 - 2024)
The placenta forms in eutherian mammals, and is responsible for the nutrition of the developing fetus. However, maternal exposure to environmental pollutants both before and during pregnancy may result in the passage of toxins through the placental barrier and into fetal tissues. The placenta is the only organ derived from both maternal and fetal tissues, and establishes a link between the fetus and the environmental exposures of the mother. The analysis of placentae for the presence of environmental pollutants offers the possibility of exposure measurements in both the mother and the developing fetus. Specifically, trace element determination in human placentae …
Silica Removal From Brine By Using Ion Exchange, Carlos R. Acevedo
Silica Removal From Brine By Using Ion Exchange, Carlos R. Acevedo
Open Access Theses & Dissertations
Local governments have been forced to look for additional water sources to satisfy the ever increasing demand for fresh water. Very often, the new water sources such as the underground water in continental territories have high salt content. Currently, reverse osmosis technology (RO) is one of the most common processes for water desalination. However, this process is limited by high silica and salt concentrations in water. At high concentrations silica clogs the membranes used in the RO process, reducing their life and increasing operational costs. In this study, quaternary ammonium resins and sulfonic acid resins were used to remove silica …