Physical Sciences and Mathematics Commons^™

Three Body Interactions Of Rare Gas Solids Calculated Within The Einstein Model, Dan D'Andrea

Masters Theses

Three body interactions can become important in solids at higher pressures and densities as the molecules can come into close contact. At low temperatures, accurate studies of three body interactions in solids require averaging the three-body terms over the molecules' zero point motions. An efficient, but approximate, averaging approach is based on a polynomial approximation of the three-body term. The polynomial approximation can be developed as a function of the symmetry coordinates of a triangle displaced from its average geometry and also as a function of the Cartesian zero point displacements from each atom’s average position. The polynomial approximation approach …

Synthesis And Characterization Of Novel Ligand For Use On Rhodium Paddlewheel Complexes, Gavin J. Rustin

Masters Theses

Dirhodium (II) paddlewheel complexes have proven to be useful catalysts in many transformations including C-H insertions, cyclopropanation, and silane insertion reactions. One deficiency of these catalysts is the inability to modulate the enantioselectivity with reactive diazo compounds. One avenue for potential improvement of paddlewheel complexes is coordinating ligands in the axial site to increase enantioselectivity. The axial site has been occupied by various ligands including Nheterocyclic carbenes, nitrogen compounds, and phosphorous compounds. This work examines compounds that can be used as ligands on dirhodium complexes that have a pendant chain containing a dibenzyl phosphite and dibenzyl phosphate, both of which …

Specific Phosphate Sorption Mechanisms Of Unaltered And Altered Biochar, Kathryn D. Szerlag

Masters Theses

Biochar has been shown to act as an effective sorbent for many organic and inorganic contaminants (including phosphate) and can help to improve the quality of our fresh water resources by preventing eutrophication. Most of the high efficiency biochar phosphate-adsorbent feedstocks are modified with chemical pretreatment, phytoremediation or anaerobic digestion to accumulate desired elements. The main objectives of this project were to first engineer magnesium (Mg) and calcium (Ca) altered biochar by chemical pretreatment followed by pyrolysis at either 350 or 550°C and evaluate their phosphate adsorption rate and potential as compared to their unaltered counterparts. Determination of surface physiochemical …

Development Of Filter-Based Surface Enhanced Raman Spectroscopic Assays For Rapid Detection Of Chemical And Biological Contaminants In Water, Siyue Gao

Masters Theses

Surface enhanced Raman spectroscopy (SERS) has been widely applied for rapid and sensitive detection of various chemical and biological targets. Here, we incorporated a syringe filter system into the SERS method to detect pesticides, protein toxins and bacteria in water. For the detection of chemical and protein targets, silver nanoparticles (Ag NPs) were aggregated by sodium chloride (NaCl) to form nanoclusters that could be trapped in the pores of the filter membrane to from the SERS-active membrane. Then a coating of capture (e.g. aptamer) was integrated on the nanoparticle substrate if needed. Then samples were filtered through the membrane. After …

The Use Of Sodium Persulfate In Hydraulic Fracturing Fluids: A Degradation Study Based On Furfural, Katherine Elizabeth Manz

Masters Theses

Hydraulic fracturing has allowed natural gas to become a viable energy source via extraction of unconventional shale reserves, but this process requires an enormous amount of water. To ensure a productive fracture, a proprietary blend of chemical additives is added to the water. In this research, a hydraulic fracturing chemical additive – an enzyme breaking agent – is analyzed for organic components using gas chromatography mass spectrometry. The chemical changes that occur over the course of a fracture are also investigated using one model chemical found in the additive, furfural, in order to help assess the environmental risk that hydraulic …

Understanding College Students’ Exam Process In A General Chemistry Course, Angela Willson

Masters Theses

The main way most college chemistry courses assess what a student has learned is through a summative exam. After introductory science courses, such as general chemistry, many students cite poor teaching and disappointing grades in these courses as a reason for dropping out of STEM programs. There has been a lack of qualitative research on students’ experiences of the complete process of taking an exam from start to finish, or the exam process, which includes preparing for an exam, taking an exam, receiving feedback, and responding to feedback after the exam has been graded.

My goal in this exploratory study …

Magnetron Sputtering And Corrosion Of Ti-Al-C And Cr-Al-C Coatings For Zr-Alloy Nuclear Fuel Cladding, Devin Alan Roberts

Masters Theses

The disaster at the Fukushima Daiichi Nuclear Power Plant in March 2011 bought renewed focus to the issue of corrosion in nuclear fuel cladding applications. This thesis reports on the background behind these issues, the investigation strategy, and the analysis of experiments focused on mitigating oxidation of Zr-alloy fuel cladding. This thesis seeks to develop magnetron sputtered Ti-Al-C and Cr-Al-C coatings for Zr-alloy substrates and characterize the as-deposited and corroded samples.

Ti-Al-C and Cr-Al-C coatings were deposited onto ZIRLO, Si, and Al₂O₃ [Aluminum Oxide] substrates under various sputtering conditions. A combinatorial sputtering method was employed to refine …

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 …

Optical Sensors For The Analysis Of Alcohols In Fuels, Kendhl Kate Witt

Masters Theses

This thesis reports the development of optical sensors to analyze alcohols in fuel samples. One optical sensor enables the analysis of phenol in aviation fuels and cellulosic biofuels. It is critical to monitor the concentration of phenols in fuels because they increase the presence of solid oxidative deposits and lower the thermal stability of fuels. Preliminary studies of another optical sensor have been conducted to detect ethanol in E10 gasoline samples. Gasoline containing ethanol is widely available and used, but the exact percentage of ethanol is not specified and varies between samples and regions. Higher concentrations of ethanol in gasoline …

Developing Synthetic Methods To Prepare Discrete Metal-Organic Nanotubes, Derek L. Mull

Masters Theses

Metal-organic nanotubes (MONTs) are an emerging class of discrete materials that are the 1D variant of metal-organic frameworks (MOFs). MONTs have potential to become an alternative 1D material to carbon nanotubes, metal oxide nanotubes, and boron nitride nanotubes because they possess an organic ligand that can be functionalized and tuned for specific applications. Despite this potential, only a handful of structures have been reported and only two examples of discrete MONTs exist in the literature. It is thus imperative to develop general methods to prepare and characterize discrete MONTs to bring them to the forefront of the scientific literature.

Efforts …

Incorporating Carbon Nanotubes Into Carbon Fiber Via Surface Modification, Robert Benjamin Ripy

Masters Theses

Ever more advanced materials need to be designed to further the exploration of avenues of science and engineering. Metals and traditional composites are not meeting the needs of today’s stringent demands for lightweight and strong materials. There is a need for advanced materials that are lighter and stronger to replace conventional materials; carbon fiber composites became the obvious choice because of their outstanding mechanical properties. Polyacrylonitrile (PAN) based carbon fiber has reached its apex in terms of its strength to weight ratio. Carbon nanotubes (CNTs) offer a lightweight and potentially stronger alternative to PAN based fibers. However, it is difficult …

Application Of Electrospray Ionization Mass Spectrometry For Ionic Liquids And Their Biodegradation Products, Sepideh Rahbarirad

Masters Theses

Ionic liquids (ILs) are organic salts with unique physico-chemical properties and are used as green alternatives to volatile organic solvents. ESI-MS is a sensitive technique to detect these stable, permanent ions. My research focused on (1) Identification of biodegradation products of ionic liquids and (2) Multiplexed tandem MS by modulation of ionization efficiency.

Studies, have demonstrated that ILs are toxic to the environment, which makes their biodegradability an important consideration. In this work, metabolites generated during the biodegradation of 1-butyl-3-methylimidazolium chloride (BMIM), a degradation resistant and commonly used ionic liquid, are identified using high performance liquid chromatography-mass spectrometry (LC-MS).

Multiplexed …

Environmental Applications Of Chromatography-Mass Spectrometry, Wisam Abdulabbas Flayyih Al Isawi

Masters Theses

Gas chromatography-mass spectrometry (GC-MS) and liquid chromatographymass spectrometry (LC-MS) are powerful analytical techniques that combine the separation power in a stationary phase with the detection power of mass spectrometry. GCMS and LC-MS have gained dominant positions in identifying and quantifying different analyte species due to their high selectivity, high sensitivity, and high reproducibility.

My research utilizes the analytical power of LC-MS and GC-MS to address two environmental issues: 1) Identification of biodegradation products of the ionic liquid 1- butyl-3-methylimidazolium chloride (BMIMCl) by an activated sludge microbial community using LC-MS and 2) identification and quantification of polycyclic aromatic hydrocarbons (PAHs) in …

Synthesis And Characterization Of Dicopper(Ii) Complexes With Biological Relevance, Ashley E. Hall

Masters Theses

The research discussed in this study focused on the design, synthesis, and characterization of new model complexes that mimic the type-3 enzyme, catechol oxidase, which oxidizes catechols to their corresponding quinones. Our approach focused on the design and synthesis new model complexes that contain a dicopper(II) center that can be fine-tuned in a variety of ways, such as sterics and exogeneous bridging molecules. This method allows a multitude of complexes to be created and compared to determine how the overall structure affects the catecholase activity of the complexes.

Two ligands were synthesized; they contain a phenolate body, two amide groups, …

Tracking Silver, Gold, And Titanium Dioxide Nanoparticles Through Drinking Water Systems By Single Particle - Inductively Coupled Plasma - Mass Spectrometry, Ariel Renee Donovan

Masters Theses

"Single particle (SP)-ICP-MS methods were developed to characterize and quantify Ti-containing, titanium dioxide, silver, and gold NP concentration, size, size distribution and dissolved metal element concentration in surface water and treated drinking water. The effectiveness of conventional drinking water treatments (including lime softening, alum coagulation, filtration, and disinfection) to remove NPs from surface water was evaluated using six-gang stirrer jar test simulations. Six-gang stirrers were used to simulate drinking water treatments including lime softening, alum coagulation, powdered activated carbon sorption, filtration, and disinfection by free chlorine. Lime softening effectively removed most nanoparticles added. Source and drinking waters from three large …

Structures And Nuclear Quadrupole Coupling Tensors Of 1,2-Dichloroethane, 1-Chloro-2-Fluoroethane And 2,3-Dichloropropene Studied Using Microwave Spectroscopy And Computational Chemistry, Asela Sampath Dikkumbura

Masters Theses

The Fourier-transform microwave (FTMW) spectra of 1,2-dichloroethane (12DCE), 1-chloro-2-fluoroethane (1C2FE) and 2,3-dichloropropene (23DCP) have been studied in the 6 to 18 GHz range to determine experimental rotational constants, nuclear quadrupole coupling constants (NQCC) and quartic centrifugal distortions constants. These three molecules have different spatial arrangements (anti and gauche) resulting from different relative orientations of chlorine and/or fluorine atoms about the C-C single bond. The lowest energy anti conformer of 12DCE is non-polar and it is not detectable by microwave spectroscopy, but rotational spectra of gauche-12DCE with three isotopologues, gauche-1C2FE with three isotopologues, and both anti- …

Theoretical Investigations Of Difluorobenzene Interacting With Ne And Infrared Analysis Of 1,1-Dichloroethylene From Synchrotron Data, Seri P. Kamari

Masters Theses

The intermolecular interactions between two molecules are of great importance in proteins, polypeptides, DNA binding, and drug binding interactions. Dimers of chemical rings such as difluorobenzene with hydrogen containing molecules such as acetylene (HCCH) and atoms such as neon are classic systems for investigating weak interactions; however, the microwave spectrum of 1,2-difluorobenzene...Ne does not behave as expected. Possible explanation of this phenomenon is that there is some large amplitude motion perturbing the spectrum.

A computational study was performed to analyze the potential energy surface (PES) of Ne or Ar with ortho, meta, and para difluorobenzene, and reveal the …

Functionalized Bodipy Dyes For Dye-Sensitized Solar Cells, Mahmoud A. Elkhalifa

Masters Theses

It is predicted that more than 20 terawatts of carbon-free energy will be demanded by 2050 to maintain a sufficient energy supply for the increasing global population, and photovoltaics are predicted to contribute significantly to the global energy needs. Dye-sensitized solar cells (DSCs) are an emerging class of photovoltaics (PV) that has produced promising power conversion efficiencies at low costs. Currently, electron recombination, dye aggregation, weak adsorption, and inefficient absorbance are among of the largest contributors to low DSC efficiencies.

BODIPY dyes are one of the most promising classes of dyes emerging for DSC application. These low molecular weight fluorophores …