Digital Commons Network^™

Multiple Channel Coherent Amplitude Modulated (Am) Time Division Multiplexing (Tdm) Software Defined Radio (Sdr) Receiver, Veerendra Bhargav Alluri

University of Kentucky Master's Theses

It is often required in communication and navigation systems to be able to receive signals from multiple stations simultaneously. A common practice to do this is to use multiple hardware resources; a different set of resources for each station. In this thesis, a Coherent Amplitude Modulated (AM) receiver system was developed based on Software Defined Radio (SDR) technology enabling reception of multiple signals using hardware resources needed only for one station. The receiver system architecture employs Time Division Multiplexing (TDM) to share the single hardware resource among multiple streams of data. The architecture is designed so that it can be …

Parametrization And Shape Reconstruction Techniques For Doo-Sabin Subdivision Surfaces, Jiaxi Wang

University of Kentucky Master's Theses

This thesis presents a new technique for the reconstruction of a smooth surface from a set of 3D data points. The reconstructed surface is represented by an everywhere -continuous subdivision surface which interpolates all the given data points. And the topological structure of the reconstructed surface is exactly the same as that of the data points. The new technique consists of two major steps. First, use an efficient surface reconstruction method to produce a polyhedral approximation to the given data points. Second, construct a Doo-Sabin subdivision surface that smoothly passes through all the data points in the given data set. …

Adaptive, Multi-Objective Job Shop Scheduling Using Genetic Algorithms, Haritha Metta

University of Kentucky Master's Theses

This research proposes a method to solve the adaptive, multi-objective job shop scheduling problem. Adaptive scheduling is necessary to deal with internal and external disruptions faced in real life manufacturing environments. Minimizing the mean tardiness for jobs to effectively meet customer due date requirements and minimizing mean flow time to reduce the lead time jobs spend in the system are optimized simultaneously. An asexual reproduction genetic algorithm with multiple mutation strategies is developed to solve the multi-objective optimization problem. The model is tested for single day and multi-day adaptive scheduling. Results are compared with those available in the literature for …

Phylogenetic Methods For Testing Significant Codivergence Between Host Species And Their Symbionts, Skyler Speakman

University of Kentucky Master's Theses

Significant phylogenetic codivergence between plant or animal hosts (H) and their symbionts or parasites (P) indicate the importance of their interactions on evolutionary time scales. However, valid and realistic methods to test for codivergence are not fully developed. One of the systems where possible codivergence has been of interest involves the large subfamily of temperate grasses (Pooideae) and their endophytic fungi (epichloae). Here we introduce the MRCALink (most-recent-common-ancestor link) method and use it to investigate the possibility of grass-epichloё codivergence. MRCALink applied to ultrametric H and P trees identifies all corresponding nodes for pairwise comparisons of …

Assessment Of Terrain Attribute Models For The Identification Of Erosion Prone Areas Suitable For The Establishment Of Grassed Waterways In An Agricultural Field Setting In The Out Bluegrass Region Of Kentucky, Adam Clellon Pike

University of Kentucky Master's Theses

The speed and accuracy of conservation planning could be improved if maps indicating areas where grassed waterways should be placed to reduce erosion could be easily created. For five central Kentucky fields, elevation data were obtained with real time kinematic (RTK) global positioning system (GPS) and from US Geological Survey (USGS) digital elevation models (DEMs). Terrain attributes were calculated from these datasets which were used as predictor variables for neural network and logistic regression analyses. Grassed waterway prediction models were developed with these analyses. The type of activation function, type of standardization procedure, number of neurons, number of preliminary runs, …

Quantifying Cellulase In High-Solids Environments, Alicia Renée Abadie

University of Kentucky Master's Theses

In recent years, fungal and bacterial cellulases have gained popularity for the conversion of lignocellulosic material to biofuels and biochemicals. This study investigated properties of fungal (Trichoderma. reesei) and bacterial (Clostridium thermocellum) cellulases. Enzymatic hydrolysis was carried out with T. reesei using nine enzyme concentration and substrate combinations. Initial rates and extents of hydrolysis were determined from the progress curve of each combination. Inhibition occurred at the higher enzyme concentrations and higher solids concentrations. Mechanisms to explain the observed inhibition are discussed. Samples of C. thermocellum purified free cellulase after 98% hydrolysis were assayed to determine …

Syntheses, Structures And Magnetic Characterization Of Di- And Trivalent Hydridotris(3,5-Dimethylpyrazol-1-Yl)Borate Cyanomanganates, Minao Tang

University of Kentucky Master's Theses

The syntheses, structures, and magnetic properties of a series of di/trivalent hydridotris(3,5-dimethylpyrazol-1-yl)borate (Tp*) cyanomanganates were investigated. Treatment of manganese(III)acetylacetonate with KTp* followed by tetra(ethyl)- ammonium cyanide affords [NEt₄][(Tp*)Mn^II(acac)(CN)] (1). Attempts to oxidize 1 with iodine affords {(Tp*)Mn^II(κ²O-acac-CN)}_n (7); a minor complex {[NEt₄][(Tp*)Mn^II(κ²O-acac-3-CN)]₂(µ-CN) (8) was also isolated.

The manganese(II) complex [NEt₄][(Tp*)Mn^II(κ²O-acac-3-CN)(κ¹N -3-NC-acac)] (2) was obtained via treatment of Mn(3-acacCN)₃ with KTp* and [NEt₄]CN. [NEt₄]₂[Mn …

Mechanistic Investigations Of The Trans Excision-Splicing And Trans Insertion-Splicing Reaction, Perry Patrick Dotson Ii

University of Kentucky Doctoral Dissertations

Group I intron-derived ribozymes are catalytic RNAs that have been engineered to catalyze a variety of different reactions, in addition to the native self-splicing reaction. One such ribozyme, derived from a group I intron of Pneumocystis carinii, can modify RNA transcripts through either the excision or insertion of RNA sequences. These reactions are mediated through the trans excision-splicing (TES) or trans insertionsplicing (TIS) reaction pathways. To increase our current understanding of these reactions, as well as their general applicability, a mechanistic and kinetic framework for the TES reaction was established. Furthermore, additional ribozymes were investigated for their ability to …

Proportional Feedback Control Of Duty Cycle For Dc Hybrid Active Power Filter, Govind N. Malleichervu

University of Kentucky Master's Theses

This thesis deals with the design and implementation of a feedback control scheme for a DC Hybrid Active Power Filter used to filter harmonics from a Switched Reluctance Motor (SRM) Drive load. Power electronic systems are non-linear & dynamic [1,3,5]. Power electronic systems employ switching circuits to maximize their efficiency at the penalty that switching circuits generate electrical noise called ripple current and voltage or conducted electromagnetic interference (EMI). The ripple current drawn by the power electronic systems needs to be attenuated to an acceptable level. Filters attenuate this to an acceptable level. Traditionally filters with passive inductors and capacitors …

Paleogene Mirelands Of The Upper Mississippi Embayment, Western Kentucky, Jennifer Marie Klein O'Keefe

University of Kentucky Doctoral Dissertations

Detailed petrography, geochemistry, and palynology together describe the depositional environments and paleoecology of an abandoned meander-fill system in western Kentucky. Oriented block petrography reveals alternating clay-rich and attrinite-rich zones of variable thickness. Woody tissues, where present, do not show dessication features and deflation layers could not be identified. Overall, petrography is indicative of a topogenous mire. Mire palyno-assemblages are less diverse than assemblages reported from clays in the region. Castanea-Cupuliferoidaepollenites assemblages dominate the entire system and other tree pollen are common; fungal spores are relatively uncommon. Weighted statistical analyses reveal ecological groupings beyond this dominance and define botanical succession within …

The Relationship Between Learning Style Preference And Achievement In The Adult Student In A Multicultural College., Matilde E. Roig

Walden Dissertations and Doctoral Studies

Minority college students have varied learning styles and process information from distinct background and cultural perspectives, which influences their learning. Accordingly, the way faculty approach teaching affects student achievement. Few minorities are in scientific fields, with a shortage of scientists predicted. A problem exists in understanding the relationship between learning style preferences and achievement of minority college students. The purpose of the study was to investigate this relationship in adult minority students in a South Florida college's biology courses. Research questions pertained to relationships between learning style preferences, race, ethnicity and grades. This quantitative study used the online Felder-Soloman Inventory …

Model Evaluation And Measurement Optimization For The Reproduction Of Artist Paint Surfaces Through Computer Graphics Renderings, Ying Chen

Theses

Light reflection models for computer graphics have been developed over the past several decades. For real paint surfaces, it is possible to model their bidirectional reflectance distribution function with simple models. A framework was established to evaluate two simple reflection models, Phong and Torrance-Sparrow, which were used to render artist paint surfaces under different illumination angles. An image acquisition system was devised to capture the images under selected illuminated angles. The parameters of the specular and the diffuse components were estimated with these image sequences. At the evaluation stage, both physicallybased metrics and psychophysical techniques were used to evaluate the …

Precision Measurements Of The Neutron Electric Form Factor At High Momentum Transfers, Ameya Suresh Kolarkar

University of Kentucky Doctoral Dissertations

The neutron, although electrically neutral, is composed of elementary charged particles and as a result, possesses a charge distribution within. The charge distribution can be studied by measuring a quantity called the neutron electric form factor, Gⁿ_E. Experiment E02-013 at Jefferson Lab’s Hall A measured Gⁿ_E at high four-momentum transfer values of Q2 = 1.2, 1.7, 2.5 and 3.4 (GeV/c)² in double polarized semi-exclusive ³He(e, e'n) scattering in quasi-elestic kinematics by measuring the transverse asymmetry A_T of the cross section.

The neutron electric form factor is essential to …

Colloid Mediated Transport Of Heavy Metals In Soils Following Reclamation With And Without Biosolid Application, Jarrod O. Miller

University of Kentucky Doctoral Dissertations

Soils disturbed by strip mining practices may have increased colloid loads moving to groundwater resources, also enhancing the transport of contaminants into our water resources. We hypothesize that contaminant transport within soils following mining is enhanced by colloid mobility. Two sites were chosen for this study, a 30-year old reclaimed strip mine in southwest Virginia and a recently mined area from eastern Kentucky. Intact reclaimed soil monoliths were retrieved from sandstone derived soils in southwestern Virginia. Reclaimed monoliths from eastern Kentucky were recreated in the lab. Intact undisturbed (native) soil monoliths representing the soils before mining were also sampled for …

Electron Field-Emission From Carbon Nanotubes For Nanomachining Applications, Jaime A. Sanchez

University of Kentucky Doctoral Dissertations

The ability to pattern in the nanoscale to drill holes, to draw lines, to make circles, or more complicated shapes that span a few atoms in width is the main driver behind current efforts in the rapidly growing area of nanomanufacturing. In applications ranging from the microprocessor industry to biomedical science, there is a constant need to develop new tools and processes that enable the shrinking of devices. For this and more applications, nanomanufacturing using electron beams offers a window of opportunity as a top-down approach since electrons, unlike light, have a wavelength that is in the order of the …

Ecosystem Restoration In The Ouachita National Forest: Evaluating The Pragmatism Of Pre-European Settlement Benchmarks, John Lawrence Davenport

University of Kentucky Doctoral Dissertations

This paper looks at the intersections of nature and culture through a study of forest ecosystem restoration efforts in the Ouachita National Forest (Arkansas and Oklahoma). Ecosystem restoration goals are often informed by a pre-European settlement (PES) condition, with an implicit (and occasionally explicit) assertion that such conditions are both more natural than and preferable to the contemporary state. In many cases resuming pre-suppression fire regimes remains a key mechanism for achieving this restored condition. This study’s three main objectives include: (1) determining how PES benchmarks arose in restoration thought, (2) examining how the choice to use a PES benchmark …

Performance Optimization Of A Structured Cfd Code - Ghost On Commodity Cluster Architectures, Pavan K. Kristipati

University of Kentucky Master's Theses

This thesis focuses on optimizing the performance of an in-house, structured, 2D CFD code – GHOST, on commodity cluster architectures. The basic philosophy of the work is to optimize the cache usage of the code by implementing efficient coding techniques without changing the underlying numerical algorithm. Various optimization techniques that were implemented and the resulting changes in performance have been presented. Two techniques, external and internal blocking that were implemented earlier to tune the performance of this code have been reviewed. What follows is further tuning effort in order to circumvent the problems associated with using the blocking techniques. Later, …

Design, Synthesis, And Pharmacological Evaluation Of A Series Of Novel, Guanidine And Amidine-Containing Neonicotinoid-Like Analogs Of Nicotine: Subtype-Selective Interactions At Neuronal Nicotinic-Acetylcholine Receptor., Aaron Joseph Haubner

University of Kentucky Doctoral Dissertations

The current project examined the ability of a novel series of guandine and amidine-containing nicotine analogs to interact with several native and recombinantlyexpressed mammalian neuronal nicotinic-acetylcholine receptor (nAChR) subtypes. Rational drug design methods and parallel organic synthesis was used to generate a library of guanidine-containing nicotine (NIC) analogs (AH compounds). A smaller series of amidine-containing nicotine analogs (JC compounds) were also synthesized. In total, >150 compounds were examined. Compounds were first assayed for affinity in a high-throughput [³H]epibatidine radioligand-binding screen. Lead compounds were evaluated in subtype-selective binding experiments to probe for affinity at the α₄β_{2 …}

Multivariate List Decoding Of Evaluation Codes With A Gröbner Basis Perspective, Philip Busse

University of Kentucky Doctoral Dissertations

Please download dissertation to view abstract.

Subsurface Characterization And Seuqence Stratigraphy Of Late Mississippian Strata In The Black Warrior Basin, Alabama And Mississippi, Carrie A. Kidd

University of Kentucky Master's Theses

A depositional framework for the Mississippian (Chesterian) Pride Mountain Formation/Hartselle Sandstone clastic tongue and the lower Bangor Limestone carbonate ramp in the Black Warrior basin, Mississippi and Alabama, is constructed from approximately 250 geophysical well logs, 15 well cuttings descriptions, and outcrop data. The framework is based upon cross sections, isopach maps, and transgressive-regressive sequence stratigraphy.

The Lowndes-Pickens synsedimentary fault block controlled sediment dispersal in during Pride Mountain/Hartselle deposition. The basin filled from the southwest, which pushed the depocenter northeastward during Hartselle deposition. The Hartselle sub-basin is composed of the Hartselle barrier-island and back-barrier deposits to the southwest, including the …

Thermal Degradation And Aging Of High Temperature Piezoelectric Ceramics, Sunil W. Gotmare

University of Kentucky Master's Theses

Piezoelectric materials have numerous applications like high temperature accelerometers, pressure, flow and NDT transducers, acoustic emission, ultrasonic cleaning, welding, high voltage generators, medical therapy etc. The commonly used piezoelectric material, PZT continues to dominate the commercial market for piezoelectric actuators applications. The primary limitations of PZT are the lower Curie temperature T_C <390^oC and rapid thermal degradation avobe 200^oC.

Continuing efforts are focused on the development of piezoelectric materials suitable for high temperature applications >200^oC. These materials will be very useful for making sensors for space exploration, oil and geothermal well drilling tools, oil …

Charge Density Wave Polarization Dynamics, Luis Alejandro Ladino Gaspar

University of Kentucky Doctoral Dissertations

We have studied the charge density wave (CDW) repolarization dynamics in blue bronze (K_0.3MoO₃) by applying symmetric bipolar square-wave voltages of different frequencies to the sample and measuring the changes in infrared transmittance, proportional to CDW strain. The frequency dependence of the electro-transmittance was fit to a modified harmonic oscillator response and the evolution of the parameters as functions of voltage, position, and temperature are discussed. We found that resonance frequencies decrease with distance from the current contacts, indicating that the resulting delays are intrinsic to the CDW with the strain effectively flowing from the contact. …

Elastic-Plastic Indentation Deformation In Homogeneous And Layered Materials: Finite Element Analysis, Siva Naga Venkata Ravi Kiran Kurapati

University of Kentucky Master's Theses

The complex phenomenon of indentation deformation is studied using finite element analysis for both homogeneous and layered materials. For the homogeneous materials, the elastic-plastic deformation at large indentation depth is studied. The variation of the load-displacement curves as well as the variation of the energy ratio with the applied indentation depth for different strain hardening indices is presented. The power law relation between the indentation load and depth for shallow indentation becomes invalid for deep indentation. The ratio of plastic energy to total mechanical work is a linear function of the ratio of residual indentation depth and maximum indentation depth. …

Efficient And Scalable Network Security Protocols Based On Lfsr Sequences, Saikat Chakrabarti

University of Kentucky Doctoral Dissertations

The gap between abstract, mathematics-oriented research in cryptography and the engineering approach of designing practical, network security protocols is widening. Network researchers experiment with well-known cryptographic protocols suitable for different network models. On the other hand, researchers inclined toward theory often design cryptographic schemes without considering the practical network constraints. The goal of this dissertation is to address problems in these two challenging areas: building bridges between practical network security protocols and theoretical cryptography. This dissertation presents techniques for building performance sensitive security protocols, using primitives from linear feedback register sequences (LFSR) sequences, for a variety of challenging networking applications. …

Metabolite Analysis Of Clostridium Thermocellum Using Capillary Electrophoresis Based Techniques, Anup P. Thakur

University of Kentucky Doctoral Dissertations

Clostridium thermocellum is a thermophilic bacterium that converts biomass to ethanol directly; however, high sensitivity of this bacterium toward ethanol limits its commercial utility. To elucidate the effect of ethanol on the growth of this bacterium a metabolite analysis of C. thermocellum was performed. The hypothesis of the project was that exogenous ethanol alters the metabolite profile of C. thermocellum. For metabolite analysis, capillary electrophoresis-electrospray ionization-mass spectrometry method (CE-ESI-MS) was developed due to highly polar and charged nature of metabolites. To increase the sensitivity of CE-ESI-MS, several parameters at the ESI interface were optimized. The application of 50% isopropanol …

Benzene-1,3-Diamidoethanethiol (Bdeth2) And Its Metal Compounds, Kamruz Md Zaman

University of Kentucky Doctoral Dissertations

There is a global need to find a permanent and readily implemented solution to the problem of heavy metal pollution in aqueous environments. A dithiol compound, benzene-1,3-diamidoethanethiol (BDETH₂), also known as N,N'-bis(2-mercaptoethyl) isophthalamide or N,N'-bis(2-mercaptoethyl)-1,3-benzenedicarboxamide, capable of binding divalent metal ions, has been synthesized and characterized. A broad range of BDET-metal compounds, spanning the periodic chart, has been prepared and characterized by IR, MS, EA, Raman, XAFS and TGA. The characteristics of the BDET-M compounds were determined through secondary reactions. In an effort to derivatize BDET-M compounds through alkylalumination a new cyclic compound, 1,3- bis(4,5-dihydrothiazolo)benzene, has …

Application Of Linear Free Energy Relationships In The Prediction Of Triglyceride/Water Partition Coefficients And Lipid Bilayer Permeability Coefficients Of Small Organic Molecules And Peptides, Yichen Cao

University of Kentucky Doctoral Dissertations

Computational methods such as linear free energy relationships (LFERs) offer a useful high-throughput solution to quickly evaluate drug developability, e.g. membrane permeability, organic solvent/water partition coefficients, and solubility. LFERs typically assume the contribution of structural components/functional groups to the overall properties of a given molecule to be constant and independent. This dissertation describes a series of studies in which linear free energy relationships were developed to predict solvation of small organic molecules in lipid formulations, specifically, triglyceride containing solvents and phospholipid-based liposomes. The formation of intermolecular HBs in triglyceride solvents (homogenous with H-bond accepting ability) and intramolecular HBs within the …

Optimizing Learning Through Teacher-Student Relationships: A Test Of The Causal Process Student Understanding Model, Nicole Denise Dobransky

University of Kentucky Doctoral Dissertations

In many ways, higher educational systems in the United States are the most extraordinary in the world. Students come from all over to study in our institutes of higher learning. As our search for an explanation of how to facilitate student learning continues, the goal of this dissertation was to examine the heavily under-researched area of teacherstudent relationships as they relate to student understanding. Using the existing body of instructional communication research, the Student Understanding Model (SUM) is proposed and tested. Data collected from 302 undergraduate students was used to test the SUM. Results provide empirical support that relational messages …

New Silks Roads: Promises And Perils Of The Internet In The Thai Silk Industry, Mark Graham

University of Kentucky Doctoral Dissertations

The Internet is often touted as a panacea for perceived deficiencies in economic development. Its space-transcending abilities, which can instantly connect producers with consumers, have the potential to cut out intermediaries and to redistribute economic surplus in a more equitable manner. This dissertation asks whether the promises of the Internet are being realized in the Thai silk industry.

The project explores the following questions: (a) At which nodes in the commodity chain is the Internet being used?; (b) How has the introduction of the Internet altered production chains and the flows of capital in the Thai silk industry?; (c) How …

A Systematic Study Of Thermodynamic And Transport Properties Of Layered CaN+1(Ru1-XCrX)NO3n+1, Vinobalan Durairaj

University of Kentucky Doctoral Dissertations

Orbital degrees of freedom play vital role in prompting novel phenomena in ruthenium based Ruddlesden-Popper compounds through coupling of orbits to spin and lattice. Physical properties are then particularly susceptible to small perturbations by external magnetic fields and/or slight structural changes. Current study pertains to the impact when a more-extended 4d Ruthenium ion is replaced by a less-extended 3d Chromium ion.

Perovskite CaRuO₃ (n=∞) is characterized by borderline magnetism and non- Fermi liquid behavior – common occurrences in quantum critical compounds. Remarkably, Cr substitution as low as x=0.05 abruptly drives CaRu_1−xCr_xO₃ from a paramagnetic …