Physical Sciences and Mathematics Commons^™

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 …

Salinity And Stratification In The Gulf Of Maine: 2001-2008, Heather E. Deese-Riordan

Electronic Theses and Dissertations

The salinity and vertical density structure (stratification) of the Gulf of Maine strongly influence the physical and biological character of the region including: circulation and transport, vertical mixing, and primary productivity. Variability in salinity and stratification also provides insights into the character and timing of the oceanic waters entering the region, a key to predicting regional climate change. This thesis addresses outstanding questions related to variability in salinity and the relative role of salinity and temperature in creating stratification. Hourly observations from Ocean Observing System buoys throughout the Gulf provide the primary data source for this investigation. Analysis of estimated …

Investigating Saxitoxin Resistance In Softshell Clams (Mya Arenaria): Patterns Of Inheritance And Improvements On Methodology For Tracking And Identification, Scott A. Hamilton

Electronic Theses and Dissertations

Attempts to characterize and study the population dynamics of the softshell clam Mya arenaria in relation to a mutation which confers resistance to paralytic shellfish toxins are complicated by a lack of non-lethal genotyping techniques, reliable tagging methods and an understanding of the inheritance patterns of the marker. Presented here, is a straightforward and non-lethal technique for clam genotyping, a new method for the long term tagging of clams, and the offspring genotype frequencies from a number of pair matings between clams of known genotype. Hemolymph extracted from M. arenaria was used directly in a polymerase chain reaction (PCR) to …

Banach Spaces On Infinitely Branching Trees, Annette B. Locke

Electronic Theses and Dissertations

An example of a Banach space, X_∞, with a nonseparable dual such that l₁ does not imbed in X_∞ is investigated. Not every weakly null sequence has a subsequence equivalent to the usual basis of c₀, but c₀ imbeds in many subspaces of X_∞. The space l₁ does imbed in X_∞^∗, the dual space of X_∞, yet weakly converging sequences in X_∞^∗ need not converge in norm.

A Phylogenetic Analysis Of Species Relationships In Hemlocks, The Genus Tsuga (Pinaceae)., Jordan David Baker

Electronic Theses and Dissertations

The genus Tsuga is comprised of eight extant species found in North America and East Asia and four species represented by fossils from Europe and Japan. This study presents the first phylogenetic analysis based on structural, biochemical, and molecular sequence data. Characters obtained from published and unpublished literature were combined with new morphological characters from seeds, seedlings, and leaf cuticle material. Results from parsimony analyses of these characters differed from the published molecular based phylogeny. The non-molecular based phylogeny resolves two separate clades, a North American and an Asian, but did not group the western North American species, as in …

Computational Investigation Of Spin Traps Using Hybrid Solvation Models., Sai Sriharsha Manoj Konda

Electronic Theses and Dissertations

The cyclic nitrone 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), and the lesser known linear phenyl-N-tert-butylnitrone (PBN) and its phosphorylated analogues have been used as spin traps for the investigation of free radicals in biological systems. Theoretical work on these molecules suggests that there are important differences in their properties between biological systems and isolated molecules in the gas phase, most likely resulting from intra and intermolecular hydrogen bonding. Most dielectric solvation models such as the polarized continuum model and COSMO are incapable of direct determination of solvent-spin trap chemical interactions. To examine this, hybrid models incorporating COSMO for long range effects and discrete solvent …

Studies Of Titanium Dioxide Nanoparticles And Surfactants Effects, Singly And In Combinations, On Luminescence Intensity Of Some Aromatic Compounds., Charles Anim Odame-Ankrah

Electronic Theses and Dissertations

Luminescence techniques are sensitive, selective, and widely used in analysis. Luminescence intensity is attenuated by quenchers. This research has focused on the use of surfactants such as CTAB, SDS, and TX-100 singly or together with TiO₂ nanoparticles to evaluate their individual and combined effects on some fluorescent aromatic compounds such as pyrene, fluoranthene, anthracene, phenanthrene, and carbazole. Rutile phase TiO₂ was synthesized using the low temperature sol-gel method. Carbazole and phenanthrene were severely quenched by all surfactants singly or in combination with TiO₂. Anthracene and fluoranthene showed some enhancement in their luminescence intensity. The most dramatic …

The Last Of The Mixed Triple Systems., Ernest Jum

Electronic Theses and Dissertations

In this thesis, we consider the decomposition of the complete mixed graph on v vertices denoted M_v, into every possible mixed graph on three vertices which has (like M_v) twice as many arcs as edges. Direct constructions are given in most cases. Decompositions of theλ-fold complete mixed graph λM_v, are also studied.

Novel Strategy For The Synthesis Of Allenes., Mark-Henry Mbahmi Kamga

Electronic Theses and Dissertations

Allenes are very important chemical reagents in organic synthesis. Due to their high reactivity, they have been extensively used to carry out a variety of unique and effective chemical transformations including but not limited to ionic and free radical additions and transition metal catalyzed cyclizations. As the chemistry of this group of compounds is explored further and their applications expanded there is a need to develop alternative and cost effective methods for their synthesis. Our approach involves the synthesis of allenes from oxa-bicyclo-alkan-2-ones by methyllithium induced Eschenmoser fragmentation of the bicyclotosylhydrazone derivatives.

Studies Of Capsaicinoids Contents Of Locally Grown And Commercial Chilies Using Reversed-Phase High Performance Liquid Chromatography., John Kailemia Muchena

Electronic Theses and Dissertations

Capsaicinoids are a class of compounds responsible for the "heat" of hot peppers. Capsaicin and dihydrocapsaicin have the highest burning effect. The aim of this work is to separate and quantify the two major capsaicinoids in fruits harvested at different stages of development and at different seasons. Simple and rapid HPLC method involves 73:27% methanol water mobile phase with C₁₈ stationary phase and UV-Vis detector set at 210 nm. The method showed good reproducibility with 1.74% - 4.72% relative standard deviations, a linear response within 0.65–45.5 and 0.25-17.5 μg/mL for capsaicin and dihydrocapsaicin, respectively. The method achieved average recovery …

Studies Of The Preparations And Use Of Sol-Gel For Enzyme Immobilization And Analytical Applications., Suzana Hamdan

Electronic Theses and Dissertations

Much attention has been paid to immobilization of enzymes to improve enzyme stability and permit its reuse. Glucose oxidase entrapment in different kinds of silica sol-gel matrices was investigated. The enzyme showed stable activity for 11 uses in the sol-gel with tetramethyl orthosilicate (TMOS) as precursor, and at least 7 uses in the sol-gel induced electrochemically with tetraethyl orthosilicate (TEOS) as precursor. The sol-gel made with TEOS as precursor and HCl as catalyst showed stability in enzyme activity for 11 uses but the activity decreases on the same sol-gel when modified with silica nanoparticles. Factors such as optimal incubation time …

Independent Domination In Complementary Prisms., Joel Agustin Gongora

Electronic Theses and Dissertations

Let G be a graph and G̅ be the complement of G. The complementary prism GG̅ of G is the graph formed from the disjoint union of G and G̅ by adding the edges of a perfect matching between the corresponding vertices of G and G̅. For example, if G is a 5-cycle, then GG̅ is the Petersen graph. In this paper we investigate independent domination in complementary prisms.

Qualitative Models Of Neural Activity And The Carleman Embedding Technique., Azamed Yehuala Gezahagne

Electronic Theses and Dissertations

The two variable Fitzhugh Nagumo model behaves qualitatively like the four variable Hodgkin-Huxley space clamped system and is more mathematically tractable than the Hodgkin Huxley model, thus allowing the action potential and other properties of the Hodgkin Huxley system to be more readily be visualized. In this thesis, it is shown that the Carleman Embedding Technique can be applied to both the Fitzhugh Nagumo model and to Van der Pol's model of nonlinear oscillation, which are both finite nonlinear systems of differential equations. The Carleman technique can thus be used to obtain approximate solutions of the Fitzhugh Nagumo model and …

Structure And Properties Of Maximal Outerplanar Graphs., Benjamin Allgeier

Electronic Theses and Dissertations

Outerplanar graphs are planar graphs that have a plane embedding in which each vertex lies on the boundary of the exterior region. An outerplanar graph is maximal outerplanar if the graph obtained by adding an edge is not outerplanar. Maximal outerplanar graphs are also known as triangulations of polygons. The spine of a maximal outerplanar graph G is the dual graph of G without the vertex that corresponds to the exterior region. In this thesis we study metric properties involving geodesic intervals, geodetic sets, Steiner sets, different concepts of boundary, and also relationships between the independence numbers and domination numbers …

Room Temperature Tunable Energy Transfer Systems In Different Solvents, Zhonghua Guo

Electronic Theses and Dissertations

The focus of this thesis is on d⁸ and d¹⁰ metal-metal interactions, e.g. weak bonding in homometallic and heterometallic systems in liquid solutions, the tunability of luminescent energy due to the variation of metal-metal interaction strength in different solvents and different concentrations, as well as energy transfer from the luminescent energy tunable d⁸ and d¹⁰ metal ions clusters as donor ions to the lanthanide ions as acceptor ions at room temperature. First, energy transfer has been studied between dicyanoaurate(I) luminescent nanocluster donor ions and Eu³⁺ and Tb³⁺ acceptor ions in aqueous solutions. The emission …

Routing In The Dark: Pitch Black, Nathan S. Evans

Electronic Theses and Dissertations

In many networks, such as mobile ad-hoc networks and friend-to-friend overlay networks, direct communication between nodes is limited to specific neighbors. Friendto-friend “darknet” networks have been shown to commonly have a small-world topology; while short paths exist between any pair of nodes in small-world networks, it is non-trivial to determine such paths with a distributed algorithm. Recently, Clarke and Sandberg proposed the first decentralized routing algorithm that achieves efficient routing in such small-world networks.

Herein this thesis we discuss the first independent security analysis of Clarke and Sandberg’s routing algorithm. We show that a relatively weak participating adversary can render …

The Burden Of Fetching Water: Using Caloric Expenditure As An Indicator Of Access To Safe Drinking Water—A Case Study From Xieng Khouang Province, Lao Pdr, Jeff La Frenierre

Electronic Theses and Dissertations

The Millennium Development Goals measure ‘access to improved drinking water’ using an indicator that defines access as the presence of an improved water source within 1 kilometer of a person’s dwelling. This purely linear measurement has significant shortcomings, including a lack of consideration for the difficulty of the terrain being traversed and the weight of the loads being carried. This paper examines in detail the human energy costs associated with fetching water, first using two Lao villages as case studies, then applying a predictive energy expenditure model to measure the potential caloric effect of variations in the age and gender …

Decompositions Of Mixed Graphs With Partial Orientations Of The P4., Adam M. Meadows

Electronic Theses and Dissertations

A decomposition D of a graph H by a graph G is a partition of the edge set of H such that the subgraph induced by the edges in each part of the partition is isomorphic to G. A mixed graph on V vertices is an ordered pair (V,C), where V is a set of vertices, |V| = v, and C is a set of ordered and unordered pairs, denoted (x, y) and [x, y] respectively, of elements of V [8]. An ordered pair (x …

Development Of A Reservoir Embayment Characterization Process To Prioritize Water Quality Improvement., Terry Shannon O'Quinn

Electronic Theses and Dissertations

To simplify water quality improvement in reservoirs, it has been suggested that efforts should be focused on smaller and more manageable units such as reservoir embayment areas. Embayments are prime locations to locate marinas, parks, beaches, and residential homes. Current data and information on reservoir embayments in Tennessee was assembled into a GIS-based database. Embayments of 11 main reservoirs were mapped and digitized in ArcGIS. Initial characterization criteria include watershed size, embayment area-watershed ratio, maximum residence time, and stream influence on embayments. The characterization process was then applied to the mapped reservoir embayments in Tennessee to identify and prioritize embayments …

Locating-Domination In Complementary Prisms., Kristin Renee Stone Holmes

Electronic Theses and Dissertations

Let G = (V (G), E(G)) be a graph and G̅ be the complement of G. The complementary prism of G, denoted GG̅, is the graph formed from the disjoint union of G and G̅ by adding the edges of a perfect matching between the corresponding vertices of G and G̅. A set D ⊆ V (G) is a locating-dominating set of G if for every u ∈ V (G)D, its neighborhood N(u)⋂D is nonempty and distinct from N( …

Salamanders Of The Mio-Pliocene Gray Fossil Site, Washington County, Tennessee., Grant Stanley Boardman

Electronic Theses and Dissertations

Screening efforts at the Gray Fossil Site, Washington County, Tennessee, have yielded a unique and diverse salamander fauna for the southern Appalachian Mio-Pliocene; including at least five taxa from three modern families (Ambystomatidae, Plethodontidae, and Salamandridae) supporting the woodland-pond interpretation of the site. All specimens represent the earliest record of their respective families in the Appalachian Mountains; with the Notophthalmus sp. vertebrae being the only Mio-Pliocene skeletal fossil known for the family Salamandridae in North America. Three types of plethodontid salamander are present, with one type representing the earliest known desmognathine. The desmognathine fossils lend credence to the 'Appalachian' origin …

Cyclic, F-Cyclic, And Bicyclic Decompositions Of The Complete Graph Into The 4-Cycle With A Pendant Edge., Daniel Shelton Cantrell

Electronic Theses and Dissertations

In this paper, we consider decompositions of the complete graph on v vertices into 4-cycles with a pendant edge. In part, we will consider decompositions which admit automorphisms consisting of:

(1) a single cycle of length v,

(2) f fixed points and a cycle of length v − f, or

(3) two disjoint cycles.

The purpose of this thesis is to give necessary and sufficient conditions for the existence of cyclic, f-cyclic, and bicyclic Q-decompositions of K_v.

Electrochemically Mediated Charge Transfer Effects On Single-Walled Carbon Nanotubes., Buddika Ka. Abeyweera 1980-

Electronic Theses and Dissertations

This thesis is based on experimental work on electrochemically mediated charge transfer effects on Single-walled carbon nanotube bundles. The study of these effects are very important towards understanding the sensitivity of gases on nanostructures like single-walled carbon nanotubes. Chapter one covers the introduction and overview of carbon nanostructures including single-walled carbon nanotubes. Chapter two covers the experimental techniques involving sample preparation, experimental setup and data acquisition. Chapter three consists of Results and the Discussions explaining the mechanisms based on charge transfer mechanism. In the final chapter, implications and the importance of the study are explained. Single-walled carbon nanotubes are used …

Detecting Malicious Software By Dynamicexecution, Jianyong Dai

Electronic Theses and Dissertations

Traditional way to detect malicious software is based on signature matching. However, signature matching only detects known malicious software. In order to detect unknown malicious software, it is necessary to analyze the software for its impact on the system when the software is executed. In one approach, the software code can be statically analyzed for any malicious patterns. Another approach is to execute the program and determine the nature of the program dynamically. Since the execution of malicious code may have negative impact on the system, the code must be executed in a controlled environment. For that purpose, we have …

Alliances In Graphs: Parameterized Algorithms And On Partitioning Series-Parallel Graphs, Rosa Enciso

Electronic Theses and Dissertations

Alliances are used to denote agreements between members of a group with similar interests. Alliances can occur between nations, biological sequences, business cartels, and other entities. The notion of alliances in graphs was first introduced by Kristiansen, Hedetniemi, and Hedetniemi in . A defensive alliance in a graph G = (V, E) is a non empty set S ⊆ V where, for all x ∈ S, |N[x] ∩ S| ≥ |N[x] − S|. Consequently, every vertex that is a member of a defensive alliance has at least as many vertices defending it as there are vertices attacking it. Alliances can …

Connectionless Approach: A Localized Scheme To Mobile Ad Hoc Networks, Yao Ho

Electronic Theses and Dissertations

According to a Gartner Group (www.gartner.com) report in September 2008, the worldwide telecommunications market is on pace to reach $2 trillion in 2008. Gartner predicts that by 2012, the ratio of mobile to fixed connections will exceed 4-to-1. The North American mobile data market grew to 141.1 million connections in 2007, with a compound annual growth rate of 41.7 percent. It is believed that a large portion will be ad hoc and multi-hop connections, which will open many opportunities for Mobile Ad hoc NETwork (MANET) applications and Wireless Mesh Network (WMN) applications. A MANET is a self-organizing multi-hop wireless network …

Modeling Scenes And Human Activities In Videos, Arslan Basharat

Electronic Theses and Dissertations

In this dissertation, we address the problem of understanding human activities in videos by developing a two-pronged approach: coarse level modeling of scene activities and fine level modeling of individual activities. At the coarse level, where the resolution of the video is low, we rely on person tracks. At the fine level, richer features are available to identify different parts of the human body, therefore we rely on the body joint tracks. There are three main goals of this dissertation: (1) identify unusual activities at the coarse level, (2) recognize different activities at the fine level, and (3) predict the …

Efficient Techniques For Relevance Feedback Processing In Content-Based Image Retrieval, Danzhou Liu

Electronic Theses and Dissertations

In content-based image retrieval (CBIR) systems, there are two general types of search: target search and category search. Unlike queries in traditional database systems, users in most cases cannot specify an ideal query to retrieve the desired results for either target search or category search in multimedia database systems, and have to rely on iterative feedback to refine their query. Efficient evaluation of such iterative queries can be a challenge, especially when the multimedia database contains a large number of entries, and the search needs many iterations, and when the underlying distance measure is computationally expensive. The overall processing costs, …

Scheduling And Resource Management For Complex Systems: From Large-Scale Distributed Systems To Very Large Sensor Networks, Chen Yu

Electronic Theses and Dissertations

In this dissertation, we focus on multiple levels of optimized resource management techniques. We first consider a classic resource management problem, namely the scheduling of data-intensive applications. We define the Divisible Load Scheduling (DLS) problem, outline the system model based on the assumption that data staging and all communication with the sites can be done in parallel, and introduce a set of optimal divisible load scheduling algorithms and the related fault-tolerant coordination algorithm. The DLS algorithms introduced in this dissertation exploit parallel communication, consider realistic scenarios regarding the time when heterogeneous computing systems are available, and generate optimal schedules. Performance …

The Forensic Analysis Of Triacetone Triperoxide (Tatp) Precursors And Synthetic By-Products, Kimberly Painter

Electronic Theses and Dissertations

Triacetone Triperoxide (TATP) is a primary high explosive that can be synthesized using commercially available starting materials and has grown in use among terrorists over the past several years. Additives present in the precursors were investigated to see if they carry through the TATP synthesis and can be detected in the final product potentially aiding in the identification of the source. Additives identified in the acetones were also identified in pre-blast and in some post-blast samples. However, these additives are present in trace quantities relative to the TATP, which coupled with the volatility and short lifetimes of some of the …