Physical Sciences and Mathematics Commons^™

The Correlation Of The Concentration Of Selected Metals Determined In Water And Fish Samples From A Public Pond., Paula Kay Edwards

Electronic Theses and Dissertations

The concentrations of heavy metals (Cd, Cu, Fe, Ni, Pb, Zn) were measured in water, and fish samples caught from the pond at Fishery Park in Unicoi County, TN. The water samples were collected once a week for 8 weeks. The amounts of metals in the muscle tissues, gill, and liver of the two fish species were measured. This was to determine if any correlation exists between the metal contents in water and those in the fish samples. The concentration ranges for the heavy metals found in the water samples are as follows: Zn 0.04-0.13; Cu, 0.00-0.00; Pb, 0.00-0.59; Cd, …

P300-Based Bci Performance Prediction Through Examination Of Paradigm Manipulations And Principal Components Analysis., Nicholas Edward Schwartz

Electronic Theses and Dissertations

Severe neuromuscular disorders can produce locked-in syndrome (LIS), a loss of nearly all voluntary muscle control. A brain-computer interface (BCI) using the P300 event-related potential provides communication that does not depend on neuromuscular activity and can be useful for those with LIS. Currently, there is no way of determining the effectiveness of P300-based BCIs without testing a person's performance multiple times. Additionally, P300 responses in BCI tasks may not resemble the typical P300 response. I sought to clarify the relationship between the P300 response and BCI task parameters and examine the possibility of a predictive relationship between traditional oddball tasks …

Conjugate Additions And Transposition Of The Allylic Alcohols Of Enol Ethers Of 1, 2-Cyclohexanedione., Barnabas Otoo

Electronic Theses and Dissertations

A variety of protected enolic forms of 1, 2-cyclohexanedione was prepared as substrates for conjugate addition studies using organocopper reagents. The sequence involved the enol ether preparation via the enolate, alkylation with an organometalic reagent, and oxidative rearrangement with pyridinium chlorochromate followed by the conjugate addition reactions. Protection of 1, 2-cyclohexanedione was achieved by reacting with chloro tert-butyldimethyl silane and subjected to alkylation. Steric problems were encountered and so an alternative protective group the methoxymethyl acetal was prepared and studied. Alkylation of these derivatives was successful; however, the oxidation was problematic and although evidence for rearrangement was observed in one …

The Sir Model When S(T) Is A Multi-Exponential Function., Teshome Mogessie Balkew

Electronic Theses and Dissertations

The SIR can be expressed either as a system of nonlinear ordinary differential equations or as a nonlinear Volterra integral equation. In general, neither of these can be solved in closed form. In this thesis, it is shown that if we assume S(t) is a finite multi-exponential, i.e. function of the form S(t) = a+ ∑ⁿ_k=1 r_ke^-σ_kt or a logistic function which is an infinite-multi-exponential, i.e. function of the form S(t) = c + a/b+e^wt, then …

The Removal Of Wood Components From Hardwood By Hot Water, Rory Jara

Electronic Theses and Dissertations

Hot-water extraction of hemicelluloses from wood is a promising technology in the integrated biorefmery concept. A particular case is where the pulp industry makes co-products such as ethanol and acetic acid besides pulp thereby maximizing the value of biomass. Similarly, the oriented strand board (OSB) industry appears to be suitable for this technical approach as it is composed of large centralized facilities. Many studies have been carried out on the kinetics and mechanism of hot-water extraction of lignocellulosics. However, most of these studies were performed in batch reactors which are not best suited to determine intrinsic kinetics of hemicellulose dissolution …

Early Stopping Of A Neural Network Via The Receiver Operating Curve., Daoping Yu

Electronic Theses and Dissertations

This thesis presents the area under the ROC (Receiver Operating Characteristics) curve, or abbreviated AUC, as an alternate measure for evaluating the predictive performance of ANNs (Artificial Neural Networks) classifiers. Conventionally, neural networks are trained to have total error converge to zero which may give rise to over-fitting problems. To ensure that they do not over fit the training data and then fail to generalize well in new data, it appears effective to stop training as early as possible once getting AUC sufficiently large via integrating ROC/AUC analysis into the training process. In order to reduce learning costs involving the …

Non-Classical Symmetry Solutions To The Fitzhugh Nagumo Equation., Arash Mehraban

Electronic Theses and Dissertations

In Reaction-Diffusion systems, some parameters can influence the behavior of other parameters in that system. Thus reaction diffusion equations are often used to model the behavior of biological phenomena. The Fitzhugh Nagumo partial differential equation is a reaction diffusion equation that arises both in population genetics and in modeling the transmission of action potentials in the nervous system. In this paper we are interested in finding solutions to this equation. Using Lie groups in particular, we would like to find symmetries of the Fitzhugh Nagumo equation that reduce this non-linear PDE to an Ordinary Differential Equation. In order to accomplish …

A Study Of Improving The Parallel Performance Of Vasp., Matthew Brandon Baker

Electronic Theses and Dissertations

This thesis involves a case study in the use of parallelism to improve the performance of an application for computational research on molecules. The application, VASP, was migrated from a machine with 4 nodes and 16 single-threaded processors to a machine with 60 nodes and 120 dual-threaded processors. When initially migrated, VASP's performance deteriorated after about 17 processing elements (PEs), due to network contention. Subsequent modifications that restrict communication amongst VASP processes, together with additional support for threading, allowed VASP to scale up to 112 PEs, the maximum number that was tested. Other performance-enhancing optimizations that were attempted included replacing …

Spousal Concordance In Academic Achievements And Intelligence And Family-Based Association Studies Identified Novel Loci Associated With Intelligence., Yue Pan

Electronic Theses and Dissertations

Assortative Mating, the tendency for mate selection to occur on the basis of similar traits, plays an essential role in understanding the genetic variation on academic achievements and intelligence (IQ). It is an important mechanism explaining spousal concordance. We used principal component analysis (PCA) for spousal correlation. There is a significant positive correlation between spouses by the new variable PC1 (correlation coefficient=0.515, p<0.0001). We further research the genetic factor that affects IQ by using the same data. We performed a low density genome-wide association (GWA) analysis with a family-based association test to identify genetic variants that associated with intelligence as measured by WAIS full-score IQ (FSIQ). NTM at 11q25 (rs411280, p=0.000764) and NR3C2 at 4q31.23 (rs3846329, p=0.000675) were 2 novel genes that haven't been associated with IQ from other studies. This study may serve as a resource for replication in other populations and a foundation for future investigations.

Cyanoscorpionates And Transition Metal Complexes., Donald Martin Johnson

Electronic Theses and Dissertations

The new dihydrobis(4-cyano-3-tert-butylpyrazolylborate) ligand has been synthesized. Isolated crystals of the thallium complex were collected and structurally characterized by X-ray diffraction. Transition metal complexes of the ligand are currently under investigation.

The Analysis Of Palaeobotanical Remains From Native American Sites In The Tennessee Region Of The Upper Cumberland Plateau., Chase W. Beck

Electronic Theses and Dissertations

Sediment samples were collected from 3 rock shelter sites and one natural pond on the Upper Cumberland Plateau. Samples were processed to quantitatively and qualitatively evaluate pollen and charcoal abundance as well as other palaeobotanicals. The analysis was to determine when prehistoric Native Americans began controlled burns to enhance resources acquisition. Samples were also analyzed for the presence of pollen to determine vegetation changes that may accompany the use of controlled burns and to determine the onset of horticulture. The Upper Cumberland Plateau is often considered a marginal area used only seasonally by Native Americans; however, management practices may have …

A Comparative Study Between The Standards Of Learning And In-Class Grades., Randetta Lynn Fuller

Electronic Theses and Dissertations

We examined the Standards of Learning mathematics scores and in-class grades for a rural Virginia county public school system. We looked at third, fourth, fifth, sixth, and seventh grades as well as Algebra I, Algebra II, and Geometry classes. The purpose of this was to determine whether or not there is a strong correlation between the Standards of Learning and the students' in-class grades. Had a strong enough correlation between the Standards of Learning and in-class grades been found we would have used only the in-class grades to predict the Standard of Learning test scores. However, we found that the …

Composing Music In Constrained Search Environments, Jeffrey Keene

Electronic Theses and Dissertations

Composing music with computers in constrained search environments adds complexities and problems not present in the traditional problem domain of generative music. The traditional and well researched mechanisms of Markov chains, genetic algorithms and data driven rule based systems do not directly map to a problem domain in which pitch choice and rhythm choice are likely to be highly limited.

We therefore explore several possible solutions to generating rhythms in extremely constrained environments with the goal of generating music that adheres to user specified constraints and is aesthetically pleasing.

Analysis Of Optical Spikes Reveals Dynamics Of Aggregates In The Twilight Zone, Nathan Briggs

Electronic Theses and Dissertations

The "biological pump," whereby phytoplankton grow in the surface ocean, aggregate, and sink, is a critical process contributing to global atmospheric CO2 drawdown and provides the vast majority of food for deep ocean and benthic ecosystems. The strength of this pump hinges on the amount of material that stick together to form larger aggregates, the sinking rates of these aggregates, and the rate at which they are consumed as they sink. However, marine aggregates, also called "marine snow," are often fragile and notoriously difficult to sample, their sinking rates are highly variable and difficult to quantify, and their concentrations can …

Toward Using Games To Teach Fundamental Computer Science Concepts, Jeffrey Michael Edgington

Electronic Theses and Dissertations

Video and computer games have become an important area of study in the field of education. Games have been designed to teach mathematics, physics, raise social awareness, teach history and geography, and train soldiers in the military. Recent work has created computer games for teaching computer programming and understanding basic algorithms.

We present an investigation where computer games are used to teach two fundamental computer science concepts: boolean expressions and recursion. The games are intended to teach the concepts and not how to implement them in a programming language.

For this investigation, two computer games were created. One is designed …

Theoretical Properties And Estimation In Weighted Weibull And Related Distributions, Ryan Roman

Electronic Theses and Dissertations

The Weibull distribution is a well known and common distribution. In this thesis, theoretical properties of weighted Weibull distributions are presented. Properties of the non-weighted Weibull distribution are also reiterated for comparison. The probability density functions, cumulative distribution functions, survival functions, hazard functions and reverse hazard functions are given for each distribution. In addition, Glaser's Lemma is applied to determine the behavior of the hazard functions. The standardized moments, differential entropy, Fisher information and results based on the likelihood function are given for each distribution as well. These results are also shown for the Rayleigh distribution, a special case of …

Greening The Green Revolution: Moving Beyond Chemicals To Sustainable Agricultural Practices, Elizabeth G. Crawley

Electronic Theses and Dissertations

Agriculture has dominated the economy of many developing countries for centuries, which has led to development policies that center on agricultural development. An obvious approach to improved production is to decrease agricultural losses in the fields and increase efficiency to markets. This study focuses on the developmental role of pesticides and chemical fertilizers on non-traditional agricultural export farming and the adoption of IPM techniques. With farmers in the Comayagua Valley of Honduras, an Asian vegetable production center for the country, as the study population, the costs and benefits of planting oriental vegetables was examined. Statistical analysis was used to examine …

Total Domination Dot Critical And Dot Stable Graphs., Stephanie Anne Marie Mcmahon

Electronic Theses and Dissertations

Two vertices are said to be identifed if they are combined to form one vertex whose neighborhood is the union of their neighborhoods. A graph is total domination dot-critical if identifying any pair of adjacent vertices decreases the total domination number. On the other hand, a graph is total domination dot-stable if identifying any pair of adjacent vertices leaves the total domination number unchanged. Identifying any pair of vertices cannot increase the total domination number. Further we show it can decrease the total domination number by at most two. Among other results, we characterize total domination dot-critical trees with total …

A Re-Evaluation Of The Pleistocene Hellbender, Cryptobranchus Guildayi, And An Overview Of Cryptobranchus Remains From Appalachian Caves., Keila Elaine Bredehoeft

Electronic Theses and Dissertations

Cryptobranchus guildayi is described as an extinct species of large salamander that is closely related to the hellbender, Cryptobranchus alleganiensis. The validity of this extinct taxon has been questioned, so an expanded osteological sample of modern hellbenders was used for comparative purposes with the C. guildayi fossil material. Based on this analysis, all supposed distinguishing morphological characteristics used to define C. guildayi can be observed in specimens of C. alleganiensis, or are based on misidentifications. Therefore, Cryptobranchus guildayi is considered to be conspecific with C. alleganiensis and taxonomically should be considered a junior synonym of the latter. The …

A Predictive Model For Secondary Rna Structure Using Graph Theory And A Neural Network., Denise Renee Koessler

Electronic Theses and Dissertations

In this work we use a graph-theoretic representation of secondary RNA structure found in the database RAG: RNA-As-Graphs. We model the bonding of two RNA secondary structures to form a larger structure with a graph operation called merge. The resulting data from each tree merge operation is summarized and represented by a vector. We use these vectors as input values for a neural network and train the network to recognize a tree as RNA-like or not based on the merge data vector.

The network correctly assigned a high probability of RNA-likeness to trees identified as RNA-like in the RAG database, …

Assessing Commercial Organic And Conventionally Grown Vegetables By Monitoring Selected Heavy Metals Found In Them., Charles Kafui Dotse

Electronic Theses and Dissertations

Commercially available organic and conventionally grown vegetables were studied by quantitative determination of selected metals in them and to determine if any differences found are statistically significant. These findings can help the consumers to determine if the vegetable products are within the recommended maximum limits as proposed by the joint FAO/WHO Expert committee on organic foods designation. Eight edible vegetables were purchased from local stores in both the organic and conventionally grown categories. Samples were digested with concentrated nitric acid and the metals monitored were zinc, copper, lead, iron, cadmium, and nickel using flame atomic absorption. The concentration range for …

Generating Compact Wasp Nest Structures Via Minimal Complexity Algorithms., Fadel Ewusi Kofi Adoe

Electronic Theses and Dissertations

Many models have been developed to explain the process of self organization-the emergence of seemingly purposeful behaviors from groups of entities with limited individual intelligence. However, the underlying behavior that facilitates the emergence of this global pattern is not generally well understood. Our study focuses on different low complexity building algorithms and characterizes how nests are built using these algorithms. Three rules postulated to be functions of wasps' building behavior were developed. First is the random rule, in which there is no constraint per the choice of site to be initiated. The second is the 2-cell rule where only sites …

Late Spring And Summer Phytoplankton Community Dynamics On Georges Bank With Emphasis On Diatoms, Alexandrium Spp., And Other Dinoflagellates, Rachel Gettings

Electronic Theses and Dissertations

Georges Bank is a highly productive continental shelf system in the Northwest Atlantic that has historically supported a rich fishery. Part of that productivity stems from annual spring diatom bloom, which is followed by post-bloom populations of flagellates, including the toxic dinoflagellate Alexandrium spp., responsible for paralytic shellfish poisoning. While the general oceanography of Georges Bank has been well studied, far less is known about phytoplankton community dynamics or even basic species distributions and abundance. This thesis is driven in part by the possible competitive interactions among species of phytoplankton which are thought to influence Alexandrium blooms on the Bank. …

Analysis Of Discrete Data Under Order Restrictions, Jeff Campbell

Electronic Theses and Dissertations

Strategies for the analysis of discrete data under order restrictions are discussed. We consider inference for sequences of binomial populations, and the corresponding risk difference, relative risk and odds ratios. These concepts are extended to deal with independent multinomial populations. Natural orderings such as stochastic ordering and cumulative ratio probability ordering are discussed. Methods are developed for the estimation and testing of differences between binomial as well as multinomial populations under order restrictions. In particular, inference for sequences of ordered binomial probabilities and cumulative probability ratios in multinomial populations are presented. Closed-form estimates of the multinomial parameters under order restrictions …

Fabrication Of Integrated Optofluidic Circuits In Chalcogenide Glass Using Femtosecond Laser Direct Writing, Troy P. Anderson

Electronic Theses and Dissertations

Femtosecond laser direct writing (FLDW) is a versatile process that uses focused femtosecond pulses to modify the physical structure of a material, which can result in a shift of optical properties such as the linear and nonlinear refractive index. If the photon energy of the femtosecond pulses lies below the material bandgap, nonlinear absorption rather than linear absorption becomes the dominant mechanism of energy transfer to the material. In this manner, a focused femtosecond pulse train can be used to fabricate functional features such as optical waveguides, diffractive optical elements, or micro-fluidic elements within the volume of a transparent medium. …

Development Of Reductive Metal Systems For The Degradation Of Energetic Compounds (Tatp, Tnt, And Rdx), Rebecca L. Albo

Electronic Theses and Dissertations

Triacetone triperoxide (TATP), a cyclic peroxide explosive, is frequently used by terrorists and amateur chemists due to the ease of synthesis and the availability of reagents. TATP is extremely sensitive to shock, heat, and friction thus a safe and rapid method for treating TATP is needed. The major objective of this dissertation was to develop in situ methodologies that could safely degrade TATP in various field situations. Initial studies focused on using zero-valent metals and mechanically alloyed metals to decompose TATP samples in both aqueous and organic solutions. The metal systems tested included zero-valent iron, magnesium, and magnesium bimetal, Mg/Pd. …

Experimental And Theoretical Approaches To Characterization Of Electronic Nonlinearities In Direct-Gap Semiconductors, Claudiu Cirloganu

Electronic Theses and Dissertations

The general goal of this dissertation is to provide a comprehensive description of the limitations of established theories on bound electronic nonlinearities in direct-gap semiconductors by performing various experiments on wide and narrow bandgap semiconductors along with developing theoretical models. Nondegenerate two-photon absorption (2PA) is studied in several semiconductors showing orders of magnitude enhancement over the degenerate counterpart. In addition, three-photon absorption (3PA) is studied in ZnSe and other semiconductors and a new theory using a Kane 4-band model is developed which fits new data well. Finally, the narrow gap semiconductor InSb is studied with regard to multiphoton absorption, free-carrier …

Search For Gas Giants Around Late-M Dwarfs, Rohit Deshpande

Electronic Theses and Dissertations

We carried out a near-infrared radial velocity search for Jupiter-mass planets around 36 late M dwarfs. This survey was the first of its kind undertaken to monitor radial velocity variability of these faint dwarfs. For this unique survey we employed the 10-m Keck II on Mauna Kea in Hawaii. With a resolution of 20,000 on the near-infrared spectrograph, NIRSPEC, we monitored these stars over four epochs in 2007. In addition to the measurement of relative radial velocity we established physical properties of these stars. The physical properties of M dwarfs we determined included the identification of neutral atomic lines, the …

Using Landscape Genetics To Assess Population Connectivity In A Habitat Generalist, Tyler Duncan Hether

Electronic Theses and Dissertations

Understanding the nature of genetic variation in natural populations is an underlying theme of population genetics. In recent years population genetics has benefited from the incorporation of landscape and environmental data into pre-existing models of isolation by distance (IBD) to elucidate features influencing spatial genetic variation. Many of these landscape genetics studies have focused on populations separated by discrete barriers (e.g., mountain ridges) or species with specific habitat requirements (i.e., habitat specialists). One difficulty in using a landscape genetics approach for taxa with less stringent habitat requirements (i.e., generalists) is the lack of obvious barriers to gene flow and preference …

Novel Improvements On The Analytical Chemistry Of Polycyclic Aromatic Hydrocarbons And Their Metabolites, Wang Huiyong

Electronic Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAH) are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. Because many of them are highly suspect as etiological agents in human cancer, chemical analysis of PAH is of great environmental and toxicological importance. Current methodology for PAH follows the classical pattern of sample preparation and chromatographic analysis. Sample preparation preconcentrates PAH, simplifies matrix composition, and facilitates analytical resolution in the chromatographic column. Among the several approaches that exist to pre-concentrate PAH from water samples, the Environmental Protection Agency (EPA) recommends the use of solid-phase extraction (SPE). High-performance liquid chromatography (HPLC) and …