Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Nanoparticles (3)
- Nanostructures (2)
- Actinide elements (1)
- Alloys (1)
- Applied sciences (1)
-
- BRINE (1)
- Bimetallic (1)
- Bimetallic Co-Mo (1)
- Biological imaging (1)
- Biosensors (1)
- Carrier mobility (1)
- Catalysts (1)
- Ceramic (1)
- CoMoS2 catalyst (1)
- Computational (1)
- Conjugated polymers (1)
- Corrosion (1)
- Crystal lattices (1)
- Crystal structures (1)
- Diffusion layers (1)
- Electrical properties (1)
- Electronic properties (1)
- Electronic structures (1)
- Explosives--Measurement (1)
- Extraction chemistry (1)
- Fermentation (1)
- Functionalized nanoparticles (1)
- Gas detectors (1)
- Gold nanoparticles (1)
- Hall effect--measurement (1)
Articles 1 - 19 of 19
Full-Text Articles in Chemistry
Biological Conversion Of Hemicellulose Extract Into Value-Added Fuels And Chemicals, Sara Lynn Walton
Biological Conversion Of Hemicellulose Extract Into Value-Added Fuels And Chemicals, Sara Lynn Walton
Electronic Theses and Dissertations
The research presented in this thesis describes the fermentation of hemicellulose extracts to produce ethanol and lactic acid. Hardwood hemicellulose extracts made at a variety of conditions using the green liquor and hot water extraction processes were characterized and then fermented by Escherichia coli K011 and Bacillus coagulans MXL-9. Hemicellulose extracts were found to contain a dilute amount of xylo-oligosaccharides and acetic acid as the major components, and many minor components including other organic acids, lignin-derived phenolics, and sugar degradation products. In order to generate ethanol economically, the fermentation must produce at least a 4% ethanol solution, which requires a …
Solvent Dependent Morphologies In Thiol-Ene Photopolymerization: A Facile Route To Synthesis Of Resorcinarene Nanocapsules, Zaharoula Marie Kalaitzis
Solvent Dependent Morphologies In Thiol-Ene Photopolymerization: A Facile Route To Synthesis Of Resorcinarene Nanocapsules, Zaharoula Marie Kalaitzis
Chemistry & Biochemistry Theses & Dissertations
Synthesis of morphologically distinct polymeric nanostructures is vital for their wide ranging applications from nanomedicine to material science. Among various polymeric nanostructures, nanocapsules in particular have attracted a lot of attention as nanoreactors and drug delivery vehicles in nanomedicine. Often, synthesis of nanocapsules is achieved by template-based approaches. A direct, template-free method for the fabrication of nanocapsules and a variety of other morphologically distinct polymeric architectures was developed. The photopolymerization of a resorcinarene thiol-ene surfactant in various solvents lead to the formation of nanocapsules, nanoparticles, fibers, distorted honeycomb-like lattices, and sheets. The progress of the polymerization reaction and the morphology …
Factors Affecting Redox Magnetohydrodynamics For Flow In Small Volumes, Matthew D. Gerner
Factors Affecting Redox Magnetohydrodynamics For Flow In Small Volumes, Matthew D. Gerner
Graduate Theses and Dissertations
Lab-on-a-chip technologies offer the possibility of developing analytical devices that are low-cost, portable, disposable, fast, and operable by non-technical personnel. Such devices require automated methods to manipulate ultra-small volumes (picoliters) of samples and solution, including pumping, stirring, and positioning. Current methods for ultra-small volume microfluidics have limitations that restrict their use including high voltage requirements, disadvantageous flow profiles or rates, and relatively complicated fabrication due to mechanical parts. Redox magnetohydrodyanmics (RMHD) that utilizes permanent magnets for portability shows promise as a micropump with ease of switching flow direction, no moving parts, compatibility with both aqueous and non-aqueous solutions, low voltages …
Evaluation Of Low-Temperature Fluoride Routes To Synthesize Actinide Nitrides And Oxide Solid Solutions, Gunanda Waduge Chinthaka Silva
Evaluation Of Low-Temperature Fluoride Routes To Synthesize Actinide Nitrides And Oxide Solid Solutions, Gunanda Waduge Chinthaka Silva
UNLV Theses, Dissertations, Professional Papers, and Capstones
Actinide mononitrides have been considered as a possible nuclear fuel for the Generation-IV nuclear reactor systems. In the process of evaluating these actinide mononitrides as nuclear fuel, it is important to study different chemical and physical characteristics of these compounds. Synthesis of the materials is thus important. Carbothermic reduction is one of the techniques that have been used to synthesize actinide mononitrides. In this method, a mixture of actinide oxide such as UO 2 and excess carbon is heat treated at temperatures greater than 1700 °C under a nitrogen atmosphere. The technique is however not promising in synthesizing the actinide …
Computational Study Of Pristine And Titanium-Doped Sodium Alanates For Hydrogen Storage Applications, Gopi Krishna Phani Dathar
Computational Study Of Pristine And Titanium-Doped Sodium Alanates For Hydrogen Storage Applications, Gopi Krishna Phani Dathar
Doctoral Dissertations
The emphasis of this research is to study and elucidate the underlying mechanisms of reversible hydrogen storage in pristine and Ti-doped sodium aluminum hydrides using molecular modeling techniques. An early breakthrough in using complex metal hydrides as hydrogen storage materials is from the research on sodium alanates by Bogdanovic et al., in 1997 reporting reversible hydrogen storage is possible at moderate temperatures and pressures in transition metal doped sodium alanates. Anton reported titanium salts as the best catalysts compared to all other transition metal salts from his further research on transition metal doped sodium alanates. However, a few questions remained …
Chasing Μ, Joseph P. Cannon
Chasing Μ, Joseph P. Cannon
Doctoral Dissertations
Conducting and semiconducting, π-conjugated polymers are promising materials for micro- and nano-optoelectronic applications because of their widely tunable physical, electrical, and optical properties. These polymers have been used to fabricate a number of electronic devices including field-effect transistors, light-emitting diodes, and photovoltaic cells. However, widespread commercial application of these devices has yet to be realized, due in part to poor electronic transport characteristics and device degradation.
Nanostructuring of conjugated polymers by various methods has demonstrated marked improvements in molecular ordering and electronic transport. In this research, nanoscale, tubular structures of semiconducting polymers fabricated by template wetting nanofabrication procedures are explored. …
Advanced Radiometry For High Discrimination Explosive Fireball Discrimination, Steven E. Slagle
Advanced Radiometry For High Discrimination Explosive Fireball Discrimination, Steven E. Slagle
Theses and Dissertations
The high explosive fireball phenomenological model for the mid wave infrared spectrum, developed by AFIT, performs classification from spectral signatures was modified to use radiometric intensities. Five bands were sequentially fit to derive the five physical fit parameters describing the fireball's temperature, size, soot absorption coefficient within 16% and emissions from the H2O and CO2 concentrations within 333% of the spectral model. This was improved by changing the model's band sizes, center, and fitting methods where all five fit parameters were matched to within 17% of spectral model. This demonstrated that a combination of radiometric intensities could …
Investigation Of Electrical And Optical Properties Of Bulk Iii-V Ternary Semiconductors, Travis C. Gomez
Investigation Of Electrical And Optical Properties Of Bulk Iii-V Ternary Semiconductors, Travis C. Gomez
Theses and Dissertations
Bulk grown III-V ternary semiconductors of In0.08Ga0.92Sb and In0.15Ga0.85As were investigated through Hall-effect and photoluminescence measurements to determine carrier concentration, mobility, sheet resistivity, and luminescence spectrum. In the past, epitaxial layers of ternary compounds have been grown on binary compound substrates, and thus very limited lattice matched ternary alloys were available. Recently, bulk grown ternary substrates have been developed, and it has presented a renewed interest in using these substrates to grow high quality ternary compounds for use in many next generation optoelectronic devices. The results of photoluminescence (PL) study for the …
Functionalized Nanoparticles For Biological Imaging And Detection Applications, Bing C Mei
Functionalized Nanoparticles For Biological Imaging And Detection Applications, Bing C Mei
Doctoral Dissertations 1896 - February 2014
Semiconductor quantum dots (QDs) and gold nanoparticles (AuNPs) have gained tremendous attention in the last decade as a result of their size-dependent spectroscopic properties. These nanoparticles have been a subject of intense study to bridge the gap between macroscopic and atomic behavior, as well as to generate new materials for novel applications in therapeutics, biological sensing, light emitting devices, microelectronics, lasers, and solar cells. One of the most promising areas for the use of these nanoparticles is in biotechnology, where their size-dependent optical properties are harnessed for imaging and sensing applications. However, these nanoparticles, as synthesized, are often not stable …
Nanofiltration Membrane Pilot Studies For Disinfection By-Product Control, Eric J. Lynne
Nanofiltration Membrane Pilot Studies For Disinfection By-Product Control, Eric J. Lynne
Electronic Theses and Dissertations
Watertown, South Dakota currently uses conventional softening to treat ground water to remove hardness, iron and manganese, and natural organic matter. The distribution system has experienced elevated concentrations of disinfection by-products, which will require additional treatment to comply with future limits set by the Stage 2 Disinfectant/Disinfection By-Products Rule. A nanofiltration membrane system has been proposed to remove additional natural organic matter from the softened water. Removing the natural organic material disinfection by-product precursors should reduce the concentration of disinfection by-products. The use of nanofiltration membranes has been previously documented to reject total organic carbon, while allowing desirable levels of …
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 …
Observed Superspin-Glass Behavior In Ni0.5zn0.5fe2o4 Nanoparticles, Antony Adair
Observed Superspin-Glass Behavior In Ni0.5zn0.5fe2o4 Nanoparticles, Antony Adair
Open Access Theses & Dissertations
In this investigation we seek to identify the magnetic behavior of Ni0.5Zn0.5Fe2O4 nanoparticles though AC-susceptibility and DC-magnetization measurements. Powder x-ray diffraction was performed to determine the purity and average diameter ( ~ 9nm) of the particles. Aditionally, structure was confirmed by comparison through the International Centre for Diffraction Data's Powder Diffraction File [52] (PDF # 08-0234).
Zero-field cooled and field cooled DC magnetization measurements (bifurcation and blocking temperature), as well as M(H) hysteresis (below and above the blocking temperature) lead us to initially suggest that the material may in fact be superparamagnetic. However, further investigation of the real AC susceptibility …
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 …
Spectroscopic Investigation Of Palladium-Copper Bimetallic Systems For Pem Fuel Cell Catalysts, Timo Hofmann
Spectroscopic Investigation Of Palladium-Copper Bimetallic Systems For Pem Fuel Cell Catalysts, Timo Hofmann
UNLV Theses, Dissertations, Professional Papers, and Capstones
One of the main barriers to commercialization of polymer electrolyte membrane fuel cells systems is cost, which is largely due to the need of platinum (Pt)-containing catalysts. In this thesis we investigate bimetallic systems consisting of a base metal (copper) and a noble metal (palladium) that, as an alloy on the nanoscale, mimic the electronic properties that make Pt desirable as a catalyst.
We present a detailed investigation of the electronic structure of carbon-supported Pd/Cu nanoparticle catalysts, model bilayer thin film systems, alloys, and various metal reference samples. We have investigated the valence band structure of the catalysts using a …
Nanocomposite Thin Films Of Au Nanoparticles Embedded In Yttria-Stabilized Zirconia For Plasmonic-Based Harsh Environment Gas Detection, Phillip Henry Rogers
Nanocomposite Thin Films Of Au Nanoparticles Embedded In Yttria-Stabilized Zirconia For Plasmonic-Based Harsh Environment Gas Detection, Phillip Henry Rogers
Legacy Theses & Dissertations (2009 - 2024)
Increased health concerns due to the emission of gases linked to the production of tropospheric ozone by petroleum based fuel burning engines has resulted in the codification of more stringent emissions regulations domestically. Emissions regulations on commercial jetliners are one of the areas to be met with stricter standards. Currently there is not a sensing technology that can detect the emissions gases in the exhaust stream of a jet turbine engine with lower detection limits that meet these standards.
Substituent Effect On The Electronic And Assembling Properties Of Asymmetric Phenazine Derivatives, Bin Cao
Substituent Effect On The Electronic And Assembling Properties Of Asymmetric Phenazine Derivatives, Bin Cao
UNLV Theses, Dissertations, Professional Papers, and Capstones
Currently, one-dimensional (1-D) nanostructures have drawn much interest because of their potential applications for nanoscale optoelectronic devices. Self-assembly (SA) based on π-conjugated systems through various intermolecular interactions has been widely used to produce 1-D nanostructure. Morphology of the assembled structures can be modified by incorporating substituents, which provide additional secondary interactions. Meanwhile, those substituents also influence the electronic properties of the molecules. Previous studies have made little effort to systematically study subsistent effects on both electronic and SA properties.
The primary objective of this research is to generate controllable 1-D structures through SA, and to provide a fundamental understanding of …
Study Of Corrosion Of Materials In The Sulfur-Iodine Hydrogen Production Cycle, Thao Trung Ho
Study Of Corrosion Of Materials In The Sulfur-Iodine Hydrogen Production Cycle, Thao Trung Ho
UNLV Theses, Dissertations, Professional Papers, and Capstones
Hydrogen is of great interest since the availability of traditional fossil fuels is in decline. Strictly speaking, hydrogen is not a primary source of energy but is an energy carrier, since energy typically must be used from another source (electricity, natural gas, coal, etc.) to produce it. Of hydrogen production techniques, the Sulfur-Iodine thermochemical water splitting process (S-I cycle), which was proposed by General Atomics (GA), is promising with its simplicity and high efficiency. Most of the chemicals are recycled except water. However, the S-I cycle operates in a harsh, corrosive environment in the presence of a mixture of iodine …
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 …
Zirconia-Magnesia Inert Matrix Fuel And Waste Form: Synthesis, Characterization And Chemical Performance In An Advanced Fuel Cycle, Kiel Steven Holliday
Zirconia-Magnesia Inert Matrix Fuel And Waste Form: Synthesis, Characterization And Chemical Performance In An Advanced Fuel Cycle, Kiel Steven Holliday
UNLV Theses, Dissertations, Professional Papers, and Capstones
There is a significant buildup in plutonium stockpiles throughout the world, because of spent nuclear fuel and the dismantling of weapons. The radiotoxicity of this material and proliferation risk has led to a desire for destroying excess plutonium. To do this effectively, it must be fissioned in a reactor as part of a uranium free fuel to eliminate the generation of more plutonium. This requires an inert matrix to volumetrically dilute the fissile plutonium. Zirconia-magnesia dual phase ceramic has been demonstrated to be a favorable material for this task. It is neutron transparent, zirconia is chemically robust, magnesia has good …