Physical Sciences and Mathematics Commons^™

The Adsorption Of 2-Ketogluconate By Goethite, Jessica Suzanne Journey

Masters Theses

The low-molecular-mass-organic acid, 2-ketogluconate (kG), has been found to exist in significant concentrations in the rhizosphere of agricultural soils. Adsorption of kG by constant potential mineral surfaces may influence soil chemical processes. This study examines influence of temperature, pH, and ionic environment on the adsorption of kG by goethite. When kG was present on the surface of goethite, the pH_pzc decreased by approximately 0.4 pH units, from pH 7.6 to pH 7.2, suggesting that kG is chemisorbed to the goethite surface via ligand exchange mechanisms. The adsorption of kG by goethite is a function of pH and ionic strength. …

Tree-Like Spaces With The Fixed-Point Property, Realized As Inverse Limits Of Special Finite Trees, Jennifer Katherine Aust

Masters Theses

In this paper, we explore some properties of inverse limit sequences on sub-spaces of Euclidean n-space. We address some well-known examples, in particular the example by David Bellamy of the "tree-like" continuum that does not have the fixed-point property. We highlight some spaces with the fixed-point property that are between snake-like continua and Bellamy's example in their level of complexity. Specifically, we prove the fixed-point property for inverse limits of limit sequences on the unit interval and on the n-ad (in two configurations), and for inverse limits that can be mapped via a continuous function with small point pre-images to …

Heats Of Solvation Of Organic Liquids In Room Temperature Ionic Liquids, Paula Jeanette Beach

Masters Theses

Ionic liquids are of potential use in industry as reusable, non-polluting solvents. Their thermochemical properties need to be known to facilitate planning of processes and experiments using these solvents. Two ionic liquids: 1-Butyl-3-methylimidazolium hexafluorophosphate ([C4mim]PF6 or [bmim]PF6) and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([hmim]NTf2) were studied using a calorimeter. Various organic liquids were introduced into the solvents and their heats of solution were measured and tabulated. Potential effects of certain functional groups such as alcohol, amine, carboxylic acid, ketone, and aldehyde were examined as well as aromatics versus chains and saturated rings.

The Use Of Lanthanide Triflates As A Method For Reducing Ytterbium(Iii) To Ytterbium(Ii), Latasha Michelle Garrett

Masters Theses

High purity lutetium (99.999%) is employed in the manufacture of cerium-doped lutetium oxyorthosilicate. Such lutetium is in high demand because the cerium-doped lutetium oxyorthosilicate is the best gamma-detecting scintillator known. Solvent extraction is the most widely used method for separating the rare earths on an industrial scale at 99.999% purity. However, this process is time consuming and requires 80-100 separation stages. The major difficulty in pure lutetium production is the separation from the adjacent element, ytterbium. If ytterbium(III) could be reduced to ytterbium(II), this would permit a different chemistry between ytterbium(II) and the trivalent state elements, allowing a more facile …

A Note On Hamel Bases, Jeremy S. Higdon

Masters Theses

The purpose of this paper is to discuss certain properties of Hamel bases. In particular, we reprove and generalize a theorem of R. Mabry (Aequations Mathematicae 71 (2006) p. 294-299) on the non-existence of nontrivial Hamel bases closed under multiplication.

The Evaluation Of A Chemical Fingerprinting Technique For Identifying The Sources Of In-Stream Sediments, Robert Alexander Hull

Masters Theses

Sediment is often listed as one of the main contributors to the impairment of surface waters throughout the United States. Sediment source identification is difficult in watersheds with complex combinations of land-uses and non-point sources because of the complexities involved in correlating water quality data, which are relatively easy to collect, to the source of a degrading component. The elemental properties of a particular soil on the landscape may be viewed as a “fingerprint”. A comparison of the elemental fingerprints of potential sources and in-stream sediment may be used to establish sediment source. The objectives of this investigation were to …

Biochemical Reactions Instigating Vision – Parameter Sensitivity Analysis, Sophonie Ketcha Tchoua

Masters Theses

The purpose of this work is to investigate the sensitivity of parameters involved in a cascade of biochemical reactions occurring in photoreceptor cells in the retina of the eye. This cascade constitutes the first stage of the elaborate process of vision, by which light captured in a photoreceptor generates an electrical signal. It is this signal that travels to the brain enabling vision.

Sensitivity on parameters was performed on an ODE model of the biochemical cascade using two methods. One method used SimLab, a statistical sensitivity analysis program. We found that there are at most five important parameters out of …

Experimental Determination Of Emissivity And Resistivity Of Yttria Stabilized Zirconia At High Temperatures, Howard Mosley Frederick

Masters Theses

The emissivity and resistivity of yttria stabilized zirconia (YsZ), Y₂O₃-ZrO₂, a ceramic material that has been specially fabricated for use as an electrically powered high temperature air heater are determined for temperatures above 2000 K. Published results of measurements of emissivity and resistivity of yttria, zirconia, and their alloys at temperatures above 2000 K are rare in the technical literature. A survey of literature describing the properties of YsZ, particularly literature concerning the ionic conduction process at high temperatures, is assembled to provide a theoretical basis for the formulation of a temperature and resistivity …

Environmental Analysis And White Cell Applications Ftir Spectroscopy, Maria Gabriela Oliveros

Masters Theses

The research is concerned with atmospheric chemistry & physics, and analyzing the environment with respect to the quantity of molecules is in the air we breathe. Fourier Transform Infrared Spectroscopy is used to identify the IR active molecules in our atmosphere. FTIR Spectrometer determines the intensity loss for molecules that have absorbed IR light. The FTIR spectroscopy is performed using the light from the sun or a carbon rod light source in the lab. A Sun-tracking device was employed to direct the sunlight into the spectrometer. Open-path measurements were made using multiple mirror reflections of the carbon rod light source …

Fusion Reaction Cross-Section Measurements Near 100Sn, Elton Lewis Freeman

Masters Theses

This thesis describes the measurement of production rates of A=109 isobars produced with beams of ⁵⁴Fe ions accelerated to 207 MeV bombarding ⁵⁸Ni target. The reaction products have been electromagnetically separated according to their mass over charge ratio and implanted into a semiconductor detector. The spontaneous decay radiation from the implanted radioactive isobars has been measured in a detection system with known detection efficiency, enabling to determine absolute intensities of observed isotopes. Known branching ratios of alpha decays of ¹⁰⁹Xe, ¹⁰⁹Te, proton decay of ¹⁰⁹I and beta delayed gamma radiation of ¹⁰⁹Te and ^{109 …}

Quantum Monte Carlo Simulations Of Many-Dimensional Harmonic Oscillators: A Study Of 2Nd And 4Th Order Propagators, Brent-Jon Bjorgvin Magnusson

Masters Theses

Because the Schrödinger equation cannot be solved analytically for systems larger than hydrogen, approximate solution methods must be applied to study systems of chemical interest. Quantum Monte Carlo is one of these methods. Quantum Monte Carlo simulations involve the diffusion of walkers through configuration space and necessitate the use of one of two imaginary time propagators, 2^nd or 4^th order. The choice of the propagator implemented depends on a balance between accuracy and efficiency. Obtaining accurate solutions is the primary objective; once this is accomplished, finding ways to make the simulations efficient is the next intention. Using a …

Assembly And Evaluation Of A Multi-Functional Heat Pulse Probe For Measurement Of Soil Properties, Andrew Conrad Sherfy

Masters Theses

A device capable of estimating soil properties quickly and accurately is of great worth to individuals in many disciplines. The multi-functional heat pulse probe (MFHPP) is an instrument which allows for simultaneous in situ measurements of soil heat capacity, thermal conductivity, thermal diffusivity, water content, water flux density, and electrical conductivity. Previous studies showed this device exhibits instrumentation and model limitations which reduce its measurement accuracy. It is important for the future use of the MFHPP to fully investigate sources of error, increase the range of testing and develop improvements to alleviate these issues.

The main objectives of this study …

Relationship Between Slug-Test And Effective Hydraulic Conductivities For 2-Dimensional Heterogeneous Aquifers, Richard Walker Donat

Masters Theses

Slug tests are one of the most common field tests used by hydrogeologists to evaluate the hydraulic conductivity of an aquifer system. Steady-state and transient (slug test) numerical simulations were run in 37, 2-dimensional randomized multifractal hydraulic conductivity fields. Each field consisted of 59,049 individual saturated hydraulic conductivity (K) values with varying numbers of hydrofacies and different degrees of spatial heterogeneity. The K_eff values were determined by examining the flux in and out of the steady-state numerical model. The K_slug values were determined by adding a slug of water to the center node of the field and evaluating …

Simulation Of Single Molecule Trapping In A Nanochannel, William Neil Robinson

Masters Theses

Trapping of single fluorescent molecules in solution is numerically simulated. Optical trapping provides insufficient force for trapping molecules much smaller than the optical wavelength. Instead, a means for trapping by sensing the molecule position and applying real-time feedback of flow to compensate diffusional displacement is used. The solution is contained in a nanochannel, reducing the problem to one spatial dimension. The position of the molecule is estimated from the fluorescence signals generated by two focused laser beams, which originate from a single laser source that is split and temporally alternated between the two focal spots. Photon collection is time gated, …

Using Automated Task Solution Synthesis To Generate Critical Junctures For Management Of Planned And Reactive Cooperation Between A Human-Controlled Blimp And An Autonomous Ground Robot, Christopher M. Reardon

Masters Theses

This thesis documents the use of an approach for automated task solution synthesis that algorithmically and automatically identifies periods during which a team of less-than-fully capable robots benefit from tightly-coupled, coordinated, cooperative behavior.

I test two hypotheses: 1) That a team’s performance can be increased by cooperating during certain specific periods of a mission and 2) That these periods can be identified automatically and algorithmically. I also demonstrate how identification of cooperative periods can be performed both off-line prior to the application and reactively during mission execution.

I validate these premises in a real-world experiment using a human-piloted Unmanned Aerial …

Analyzing The Effects Of Coupons And Promotion In The Grocery Retail Sector, Milena Hanna Chotard

Masters Theses

Modern scanner technology is pervasive throughout the retailing sector of the economy and is almost universal in the food retail industry. Along with loyalty programs, it has led to the development of massive databases which accurately and proficiently track the purchasing habits of customers. Making use of this information is one of the most important efforts in the management of this sector to further increase profitability.

This thesis explores the application of several statistical techniques to extract specific information from two large databases of customer purchasing behavior at a major US grocery chain. In particular, we first focus on the …

The Synthesis And Stability Of Endohedral Actinium-225(225Ac@C60), Jofa Gideon Mwakisege

Masters Theses

Due to their chemical and thermodynamic stability, fullerenes could play an important role in encapsulation of radionuclides for applications in radio-immunotherapy. In this thesis, we report the first synthesis of actinium endohedral fullerenes. The alpha-emitter Actinium-225 (²²⁵Ac, t_1/2 =10 d) was trapped in fullerenes by the direct current (D.C) arc discharge-catcher method in a He atmosphere. Endohedral ²²⁵Ac and the bulk of fullerene C₆₀ was dissolved from the catcher electrode (a Pt disk covered with a thin layer of C₆₀) in toluene under N₂, and converted to the malonic ester derivative. …

L-Encoder: Video Transcoding In The Logistical Network, Harold Thomas Gonzales

Masters Theses

Transcoding, the transformation of digital information from one encoding format to another, is a prominent operation in the realm of digital video and audio. This process of changing the encoding formats of multimedia files and streams is now a common task for many users due in part to the prevalence of portable media players and consumer electronic devices for digital media, which place constraints on the file and stream formats they can play. The transcoding process is often both data and compute intensive due to both the large data requirements of modern media formats from sources such as HDTV and …

Optimization Of Cosmological Simulations With Artificial Intelligence, Jay Billings

Masters Theses

Galaxy collisions are an important part of the large-scale structure of the Universe and an important catalyst for intragalactic processes like star formation. Therefore, realistic models of these interactions are an important part of any theory that plans to accurately describe the evolutionary processes of the Universe and, given the size of the problem, efficient computation and data analysis are key. This dissertation presents a proof-of-concept that an artificial intelligence suite, nominally composed of a genetic algorithm and neural network, can optimize the search of the galaxy collision parameter space. Furthermore, this dissertation discusses the possibility that this method can …

Ground Penetrating Radar Investigations On The Relationship Between Horizontal Sub-Wavelength ‘Thin-Layer’ Bedrock Fractures And Reflection Amplitudes, Kevin E. Burns

Masters Theses

Several theoretical equations that predict sub-wavelength ‘thin-layer’ reflection amplitudes are compared to the results of a series of controlled ground penetrating radar surveys using 1 GHz transducers over a physical model of a horizontal bedrock fracture. Two large plastic (UHMW-PE) blocks, separated by one or more stacked inserts (polyethylene; ~0.1 mm thick) for a total of 101 surveys, generate a modeled fracture with an aperture ranging from 0-300 mm. All existing theoretical reflection coefficient equations fail to predict observed reflection amplitude oscillations in the data when the fracture aperture is less than 1/48 of a wavelength. The only theoretical formulation …

The Utilization Of Microwave Irradiation In Organic Synthesis: Organotrifluoroborate And Alumina Chemistry, Arie A. Dadush

Masters Theses

The utilization of microwave irradiation in chemistry started in the 1950’s. Due to operational difficulties, organic chemists only began using microwaves in the mid- 1980’s, when better instruments were invented. This work describe the utilization of microwaves in two areas of organic chemistry: microwave enhanced reactions using organotrifluoroborates and microwave irradiation reactions catalyzed by highly acidic alumina.

In part one, a basic understanding of microwave irradiation is presented followed by the exploration of three major reactions. The first comprises the coupling of allyl acetate and cinnamyl acetate with various substituted potassium arylvinyltrifluoroborates to produce a variety of 1,4-dienes. The second …

Observation Of Analyte-Induced Deflections For Uncoated Microcantilevers Using The Focused Ion Beam Procedure, Jacques S. Stacco

Masters Theses

It has been found that structural modifications, involving the creation of submicron scale grooves on uncoated silicon nitride microcantilevers, allow microcantilevers to display analyte-induced deflections which have not been previously observed. The submicron grooves were created through the use of a focused ion beam procedure to mill deep and narrow grooves without the subsequent deposition of a chemically reactive coating. These modifications significantly increase (by approximately 400%) an uncoated microcantilever’s ability detect analytes such as water vapor, ethyl alcohol, acetone vapor, argon, and 1-mononitrotoluene. The intention of the experiment was to achieve greater microcantilever deflections by increasing an uncoated microcantilever’s …

Amino Acid Analysis Of Marine Sediments, Hauraki Gulf, New Zealand, Tabbatha A. Cavendish

Masters Theses

Amino acid compositions, bulk organic carbon, total nitrogen, and total organic matter were measured for eight sediment samples from the Hauraki Gulf, New Zealand, in order to assess the source and fate of organic matter in a shallow marine environment. Samples were collected from near-shore and off-shore shore sites, as well as from a site receiving freshwater input from multiple rivers. A comparison of carbon, nitrogen, and amino acid compositions of samples between 1 cm depth (Uhle 2004) and 5 cm depth was used to assess changes in organic matter composition through time. Amino acid analyses in particular should be …

Modeling The Ground State Baryon Octet Using A Generalization Of The Lagrange Triangle Solution, Matthew P. Duran

Masters Theses

The baryon octet is modeled using relativistic and nonrelativistic Hamiltonians with interquark confining potentials. Using the works of Crater, a nonrelativistic three-body Hamiltonian is obtained where the corresponding eigenvalue equation will be shown to be separable and can be treated as three two-body like systems. Next, using relativistic constraint dynamics, our eigenvalue equation is treated relativistically following the works of Sazdjian and Yang. Using the free-mass-shell Hamiltonian constraints, Yang gives us an effective energy and reduced mass of relative motion for two particle systems which we expand to a three body case. With the help of work done by Sazdjian, …

Tectonometamorphic Evolution Of The Eastern Blue Ridge: Differentiating Multiple Paleozoic Orogenic Pulses In The Glenville And Big Ridge Quadrangles, Southwestern North Carolina, Donald W. Stahr

Masters Theses

New field and analytical data collected in the eastern Blue Ridge (EBR) of southwestern North Carolina reveal a complex, polyphase thermotectonic history, and delimit the timing of previously unrecognized orogenic pulses in a portion of the southern Appalachian orogenic core. Detailed geologic mapping of the Glenville and Big Ridge 7.5’ quadrangles delineated the location of the Chattahoochee fault, a tectonic boundary separating the western Tugaloo terrane from distinct central Blue Ridge terranes.

Zircon geochronologic data for two EBR granitoids in the map area indicate emplacement occurred at ~335 Ma, making these plutons among the youngest recognized in the EBR. Bulk-rock …