Physical Sciences and Mathematics Commons^™

Asymptotic And Numerical Analysis Of Time-Dependent Wave Propagation In Dispersive Dielectric Media That Exhibit Fractional Relaxation, Matthew Frank Causley

Dissertations

This dissertation addresses electromagnetic pulse propagation through anomalously dispersive dielectric media. The Havriliak-Negami (H-N) and Cole-Cole (C-C) models capture the non-exponential nature of such dielectric relaxation phenomena, which is manifest in a variety of dispersive dielectric media. In the C-C model, the dielectric polarization is coupled to the time-dependent Maxwell's equations by a fractional differential equation involving the electric field. In the H-N case, a more general pseudo-fractional differential operator describes the polarization.

The development and analysis of a robust method for implementing such models is presented, with an emphasis on algorithmic efficiency. Separate numerical schemes are presented for C-C …

Active Caching For Recommender Systems, Muhammad Umar Qasim

Dissertations

Web users are often overwhelmed by the amount of information available while carrying out browsing and searching tasks. Recommender systems substantially reduce the information overload by suggesting a list of similar documents that users might find interesting. However, generating these ranked lists requires an enormous amount of resources that often results in access latency. Caching frequently accessed data has been a useful technique for reducing stress on limited resources and improving response time. Traditional passive caching techniques, where the focus is on answering queries based on temporal locality or popularity, achieve a very limited performance gain. In this dissertation, we …

Application Of Raman Spectroscopy In Pharmaceuticals, Anna Zarow

Dissertations

Experimental research on the use of Raman spectroscopy as an in- and on-line sensing tool and a complementary characterization technique for pharmaceutical applications is presented in this thesis. In the first chapter following a broad overview, the use of Raman spectroscopy, together with x-ray powder diffraction, scanning electron microscopy (SEM) and differential scanning calorimetry, for multilevel characterization of cryomilled powders, and the melt-grown amorphous phase of griseofulvin, a model active pharmaceutical ingredient (API), is presented and discussed in detail. A key feature was the observation of a broad inelastic background superimposed on the Raman spectra of cryomilled powders, which is …

Photopolymerized Thiol-Ene Networks For Gas Barrier And Membrane Applications, Luke Kwisnek

Dissertations

Gas transport and free volume properties of photopolymerized thiol-ene networks for various applications are reported. For basic, commercially-available thiol-ene formulations, oxygen permeation was strictly dependent on the difference between T_test (room temperature for this work) and network T_g. Networks with T_g near T_test demonstrated the lowest values of permeability, diffusivity, and solubility. A robust, high-barrier network was selected for further modification. New networks with embedded functionality were formed using a two-step approach. Thio-Michael addition of a tetrathiol to monofunctional acrylates formed new functional thiol monomers. These functional thiols were combined with an isocyanurate-based triene and …

Ruthenium-Based Olefin Metathesis Catalysts Bearing Ph-Responsive Ligands: External Control Of Catalyst Solubility And Activity, Shawna Lynn Balof

Dissertations

Sixteen novel, Ru-based olefin metathesis catalysts bearing pH responsive ligands were synthesized. The pH-responsive groups employed with these catalysts included dimethylamino (NMe₂) modified NHC ligands as well as N-donor dimethylaminopyridine (DMAP) and 3-(o-pyridyl)propylidene ligands. These pH-responsive ligands provided the means by which the solubility and/or activity profiles of the catalysts produced could be controlled via acid addition. The main goal of this dissertation was to design catalyst systems capable of performing ring opening metathesis (ROMP) and ring closing metathesis (RCM) reactions in both organic and aqueous media.

In an effort to quickly gain access to new …

Cloud Shadow Detection And Removal From Aerial Photo Mosaics Using Light Detection And Ranging (Lidar) Reflectance Images, Glover Eugene George

Dissertations

The process of creating aerial photo mosaics can be severely affected by clouds and the shadows they create. In the CZMIL project discussed in this work, the aerial survey aircraft flies below the clouds, but the shadows cast from clouds above the aircraft cause the resultant mosaic image to have sub-optimal results. Large intensity variations, caused both from the cloud shadow within a single image and the juxtaposition of areas of cloud shadow and no cloud shadow during the image stitching process, create an image that may not be as useful to the concerned research scientist. Ideally, we would like …

Modification And Evaluation Of Fuel Cell Membranes, Amol Prataprao Nalawade

Dissertations

The primary goals of this study were modification of existing Nafion^® membranes and characterization of newly developed hydrocarbon-based membranes for high temperature fuel cell applications. Various Nafion^®/silicate nanocomposites were formulated via in situ sol-gel reactions for tetraethylorthosilicate. Different silicate composition profiles generated across membrane cross-sections were investigated by EDAX/ESEM. Composite water uptake, proton conductivity and fuel cell performance were comparable to that of unmodified Nafion^®. Tafel analysis showed better electrode kinetics for composites having more silicate in the middle and less or no silicate at electrolyte-electrode interfaces. All composites showed reduced fuel cross-over and superior …

A Methodology To Develop A Communication Protocol For Visualizing Simulations In A Collaborative Virtual Reality Environment, Lacey Suzanne Duckworth

Dissertations

In the technology field, simulations and collaborative virtual reality environments (CVREs) are not generally combined because it is complicated to develop large scale simulations within CVREs. The complexity of combining these two technologies in order to form a better form of visualization stems from the lack of a methodology to help derive these scalable simulations. Simulations require very complex calculations that the CVRE cannot perform as it is overloaded in calculations for the maintenance and stability of the environment itself. Since the simulation cannot be held within the CVRE, the solution is to move the simulation external to the CVRE …

Sensitive Detection Of High Explosives Using Electrogenerated Chemiluminescence, Suman Parajuli

Dissertations

The core of this dissertation lies in the search of analytical tools which can be used to detect and quantify the high explosives confiscated from suspects in transportation hubs and from soil and water bodies where these explosives pose a greater threat to public health and safety. High explosives, namely, hexamethylene triperoxide diamine (HMTD), triacetone triperoxide (TATP), trinitrotoluene (TNT), and pentaerythritol tetranitrate (PETN), were detected and quantified by electrochemical methods such as electrogenerated chemiluminescence (ECL) and cyclic voltammetry (CV).

Sensitive detection and quantification of HMTD, one commonly used explosive by terrorists, was presented first in this dissertation on the basis …

A Molecular Dynamics Simulation Based Principal Component Analysis Framework For Computation Of Multi-Scale Modeling Of Protein And Its Interaction With Solvent, Tao Wu

Dissertations

This dissertation presents a new computational framework for calculating the normal modes and interactions of proteins, macromolecular assemblies and surrounding solvents. The framework employs a combination of molecular dynamics simulation (MD) and principal component analysis (PCA). It enables the capture and visualization of the molecules' normal modes and interactions over time scales that are computationally challenging. It also provides a starting point for experimental and further computational studies of protein conformational changes.

A protein's function is sometimes linked to its conformational flexibility. Normal mode analysis (NMA) and various extensions of it have provided insights into the conformational fluctuations associated with …

Modeling Of Magnetic Field Driven Simultaneous Assembly, Rene David Rivero

Dissertations

The Magnetic Field Driven Simultaneous Assembly (MFDSA) is a method that offers a non-statistical and deterministic solution to the problem of assembly via batch processing; a hybrid of serial and parallel processing. The technique requires the use of electromagnets as well as soft and hard magnetic materials that are applied to devices and recesses respectively. The MFDSA approach offers the ability to check and correct errors in real-time and is capable of scalable, versatile, and high-yield integration.

Devices, coated with a layer of soft magnetic material, are moved from initial to final positions along predetermined pathways through the action of …

Radio-Derived Three-Dimensional Structure Of A Solar Active Region, Samuel D. Tun

Dissertations

Solar active regions are the source of the most violent events observed on the Sun, some of which have a direct impact to modern civilization. Efforts to understand and predict such events require determination of the three-dimensional distributions of density, temperature, and magnetic fields above such active regions. This thesis presents the structure of the solar atmosphere above active region AR 10923, observed on 2006 Nov 10, as deduced from multi-wavelength studies including combined microwave observations from the Very Large Array (VLA) and the Owens Valley Solar Array (OVSA). The VLA observations provide excellent image quality at a few widely …

Face Recognition Using Multiple Features In Different Color Spaces, Zhiming Liu

Dissertations

Face recognition as a particular problem of pattern recognition has been attracting substantial attention from researchers in computer vision, pattern recognition, and machine learning. The recent Face Recognition Grand Challenge (FRGC) program reveals that uncontrolled illumination conditions pose grand challenges to face recognition performance. Most of the existing face recognition methods use gray-scale face images, which have been shown insufficient to tackle these challenges. To overcome this challenging problem in face recognition, this dissertation applies multiple features derived from the color images instead of the intensity images only.

First, this dissertation presents two face recognition methods, which operate in different …

Pattern Formation In Oscillatory Systems, Hui Wu

Dissertations

Synchronization is a kind of ordinary phenomenon in nature, the study of it includes many mathematical branches. Phase space is one of the most powerful inventions of modern mathematical science. There are two variables, the position and velocity, that can describe the 2-dimensional phase space system. For example, the state of pendulum may be specified by its position and its velocity, so its phase space is 2-dimensional. The state of the system at a given time has a unique corresponding point in the phase space. In order to describe the motion of an oscillator, we can talk about its motion …

Leach-Sm: A Protocol For Extending Wireless Sensor Network Lifetime By Management Of Spare Nodes, Bilal Abu Bakr

Dissertations

Operational lifetime of a wireless sensor network (WSN) depends on its energy resources. Significant improvement of WSN lifetime can be achieved by adding spare sensor nodes to WSN. Spares are ready to be switched on when any primary (a node that is not a spare) exhausts its energy. A spare replacing a primary becomes a primary itself.

The LEACH-SM protocol (Low-Energy Adaptive Clustering Hierarchy with Spare Management) proposed by us is a modification of the prominent LEACH protocol. LEACH extends WSN lifetime via rotation of cluster heads but allows for inefficiencies due to redundant sensing target coverage. There are two …

Investigating The Influence Of Organic Acids On Uraninite Solubility And Uranyl Sorption Onto Kaolinite, Michelle L. Barger

Dissertations

Within anoxic near surface aqueous settings where U0_2(S) may be released an opportunity to encounter and complex with organic acids may occur. Reactions between U0_2(S) and ligands may promote the solubility and mobility of uranium. Organic ligands investigated in the dissolution work include citric acid, NTA and EDTA. Exposure to the ligands had little effect on U0_2(S) solubility. The log activity of U0_2(S) hydrolysis under reduced conditions was -6.56. Under all measured conditions of ligand concentration, the data consistently show an increase in uranium concentration to a median log U activity of -4.89. The observed solubility …

Relativistic R-Matrix Theory, Janina Grineviciute

Dissertations

We have developed a relativistic coupled{channel reaction theory in which binary break-up channels satisfy a relative Dirac equation. This theory is developed by extending the R-matrix formalism of Lane and Thomas to the relativistic case and implementing the Dirac oscillator basis. The motivation for this project is testing po- tentials for the dense matter calculations and generating relativistic wave functions for the nal states in the knockout reactions. As an example of the formalism we have calculated observables for the proton scattering on light-to-medium weight nuclei in the relativistic impulse approximation using the relativistic Love-Franey amplitudes of Horowitz. The R-matrix …

Glucosamine-Induced Insulin Resistance In Primary Rat Hepatocytes And The Role Of Selenium As An Insulin Mimetic, Sandhya N. Adiyodi Veetil

Dissertations

Type 2 diabetes is mediated by insulin resistance, the inability of insulin to elicit a normal biological response in insulin responsive tissues. Several cellular models have been utilized to determine the mechanism of induction of insulin resistance but questions remain unanswered. One model, implicates the products of the Hexosamine Biosynthetic Pathway (HBP) in the induction of insulin resistance under hyperglycemia. The major end product of HBP, UDP-GlcNAc, is the substrate for O-GlcNAc transferase, an enzyme that catalyzes the O-GlcNAcylation of numerous proteins. This modification may play a role in induction of insulin resistance and thus needs to be evaluated in …

An Analog Experiment Comparing Goal-Free Evaluation And Goal Achievement Evaluation Utility, Brandon W. Youker

Dissertations

Goal-free evaluation (GFE) is the process of determining the merit of an evaluand independent of the stated or implied goals and objectives, whereas goal achievement evaluation (GAE), as the most rudimentary form of goal-based evaluation, determines merit according to the evaluand’s level of accomplishment with regard to its goals. This study examines the utility of GAE and GFE from the perspective of the evaluation’s intended users. In the study, two evaluation teams, goal achievement and goal-free, independently and simultaneously evaluate the same human service program. Each team produced a final evaluation report, which was read by the evaluation’s users, who …

Bayesian Item Response Theory: Statistical Inference And Power Analysis, Jason W. Bodnar

Dissertations

The regulatory pharmaceutical approval process is flawed in that industry clinical trials (ICTs) are always powered for efficacy and rarely powered for safety. The key safety parameter is the adverse event (AE). This practice may result in efficacious products with confounded safety. An ICT’s ability to be powered for detecting AE trends may improve patient safety. Therefore, this dissertation’s purpose was to determine if power analysis resulted in feasible sample sizes for substantiating AE hypotheses. AEs were modeled with three Bayesian 2PL IRT models. The unidimensional latent trait, transfusion-related AE, was modeled as a patient predisposition for experiencing an AE. …

Hamiltonicity And Connectivity In Distance-Colored Graphs, Kyle C. Kolasinski

Dissertations

Abstract attached as separate file.

Commissioning Of The Helical Orbit Spectrometer: A New Device For Measuring Nuclear Reactions In Inverse Kinematics, Jonathan C. Lighthall

Dissertations

The Helical Orbit Spectrometer (HELIOS) at Argonne National Laboratory is the first implementation of a radical new concept for measuring nuclear reactions. Direct nuclear transfer reactions are powerful tools for studying the properties of the atomic nucleus. A traditional example is the neutron-transfer reaction (d ,p), wherein an accelerated beam of deuterons d bombards a heavy target. The incoming deuteron transfers a neutron to the target nucleus and the outgoing proton p is detected to study the properties of the residual heavy nucleus. A new frontier of nuclear reaction studies involving short-lived exotic nuclei—which are unsuitable for use …

Robust Adaptive Scheme For Linear Mixed Models, Gabriel Asare Okyere

Dissertations

If the underlying distribution of a statistical model is known then a procedure which maximizes power and efficiency can be selected. For example, if the distribution of errors is known to be normal in a linear model then inference based on least squares maximizes power and efficiency. More generally, if this distribution is known then a ranked based inference based on the appropriate rank score function has maximum efficiency. In practice, though, this distribution is not known. Adaptive schemes are procedures which hopefully select appropriate methods to optimize the analysis.

Hogg (1974) presented an adaptive rank-based scheme for testing in …

A Comparative Analysis Of The Origin And Divine Causation Of Death In Ancient Near Eastern Literature And In The Old Testament, Lazarus Castang

Dissertations

The present dissertation attempts a comparative analysis of both the origin of death in the creation accounts and the divine causation of death in the main flood accounts in the ancient Near Eastern (ANE) literature and the Hebrew Old Testament (OT). Both literatures are examined for their implicit or explicit conceptions of the origin and divine causation of death. The origin of death in the ANE literature is located in the Egyptian Osirian myth and the Mesopotamian Enki-Ninmah myth, Enûma Elish, Epic of Gilgamesh, and the Adapa legend. The divine causation of death is studied in the Eridu Genesis, Atra-Hasis …

Electron Transmission Characteristics And The Production Of Narrow Beams Using Glass Optics, Buddhika Senarath Dassanayake

Dissertations

Transmission of electrons through an insulating single cylindrically-shaped glass capillary of microscopic dimension has been investigated. Samples made with Borosilicate glass (PYREX 7740) were subjected to bombardment of 300-1000 eV electrons. Transmitted electrons were analyzed using a parallel-plate spectrometer coupled to a channel electron multiplier.

The transmitted electron intensity was found to decrease with increasing sample tilt angle relative to the direction of the primary beam. Two regions of transmission were found: direct where there is no interaction of the beam with the inner capillary wall, and indirect where the beam does interact with the wall. The rate of transmission …

Robust Nonparametric Methods For Regression To The Mean Model, Therawat Wisadrattanapong

Dissertations

Regression to the mean is a statistical phenomenon that often confounds treatment effects in experiments. Consider an experiment involving a treatment, in which a response is measured (baseline) on a subject then a treatment is applied and a second measurement is taken. Then under many bivariate models for the pair of responses (including the bivariate normal), the predicted response of the second measurement will regress to the mean. In experiments where the second response is only taken for a select sample, say above a cutoff value, then this regression to the mean effect may mistakenly be thought of as a …

Summative Confidence, Paul Cristian Gugiu

Dissertations

Often the singular goal of an evaluation is to render a summative conclusion of merit, worth or feasibility that is based on multiple streams of multidimensional data. Exacerbating this difficulty, conducting evaluations in real-world settings often necessitates implementation of less than ideal study designs. This reality gets further complicated by the standard method for estimating the precision of results via the confidence interval (CI). Traditional CIs offer a limited approach for understanding the precision of a summative conclusion. This dissertation develops and presents a unified approach for the construction of a CI for a summative conclusion (SC).

This study derived …

Spectroscopic Study Of New Sensors For Organophosphates, Metals, And Cyanide Based On Rhodamine And Cholic Acid Derivatives, Arambe Gedara Aruna Weerasinghe

Dissertations

Despite the increasing interest in developing sensors for nerve gas agents, efficient detection remains challenging. Among the various sensors developed so far, fluorescence sensors play an important role due to their simplicity. We developed six new rhodamine-based compounds that can be used as fluorescent turn-on sensors. Compound 1 and 3 gave high fluorescent enhancement with diethyl chlorophosphate (DCP) compared to the other compounds. Very high selectivity and sensitivity were observed as these compounds did not show significant fluorescent enhancement with dimethyl methylphosphonate (DMMP), HC1 and transition metal ions. The potential sensor can be used in solution as well as on …

Characterizing Potential Sustainable Energy Feedstocks, Jesse George Thompson

Dissertations

Trap grease offers a promising and less expensive alternative to food grade vegetable oils for biodiesel production, but its commercial marketability could be affected by its intense and offensive odor. Identification, quantitation and eventual elimination of the odorant compounds are vital challenges that need to be addressed before commercialization can be achieved. A rapid method using HS-SPME and GC/MS was developed in this study to identify and quantify the major volatile odorant compounds present in trap grease. The main odorant compounds were identified as short chain free fatty acids (SC-FFA) from C₄ - C₁₀.

Sensory evaluations by …

Debugging Support For Message-Passing Based Concurrent Software, Mohamed Medhat Elwakil

Dissertations

Today, multi-core processors are used in all computing aspects, including embedded systems such as mobile devices. In order for software programs to benefit from the transition to multi-core processors, the programs need to be concurrent.

Recent research shows that programs developed using the message-passing model can scale better than programs developed using the shared-memory model. However, the message-passing model is not widely adopted, partly, because of the lack of debugging tools. Debugging message-passing programs is very intricate due to their inherent nondeterministic behavior; even with the same input, a program may behave differently when executed multiple times. Bugs in message-passing …