Physical Sciences and Mathematics Commons^™

When Wells Run Dry: Water And Tourism Along The Western Coast Of Nicaragua, Gary Thomas Lavanchy

Electronic Theses and Dissertations

This dissertation uses a political ecology approach to examine the relationship between tourism development and groundwater in southwest Nicaragua. Tourism in Nicaragua is a booming industry bolstered by ‘unspoiled’ natural beauty, low crime rates, and government incentives. This growth has led to increased infrastructure, revenue, and employment opportunities for many local communities along the Pacific coast. Not surprisingly, it has also brought concomitant issues of deeper poverty, widening gaps between rich and poor, and competition over natural resources. Adequate provisions of freshwater are necessary to sustain the production and reproduction of tourism; however, it remains uncertain if groundwater supplies can …

Rapid Scan Electron Paramagnetic Resonance (Epr) And Digital Epr Development, Zhelin Yu

Electronic Theses and Dissertations

Rapid scan electron paramagnetic resonance (EPR) was developed in the Eaton laboratory at the University of Denver. Applications of rapid scan to wider spectra, such as for immobilized nitroxides, spin-labeled proteins, irradiated tooth and fingernail samples were demonstrated in this dissertation. The scan width has been increased from 55 G to 160 G. The signal to noise (S/N) improvement for slowly tumbling spin-labeled protein samples that is provided by rapid scan EPR will be highly advantageous for biophysical studies. With substantial improvement in S/N by rapid scan, the dose estimation for irradiated tooth enamels became more reliable than …

Improved Full-Newton-Step Infeasible Interior-Point Method For Linear Complementarity Problems, Mustafa Ozen

Electronic Theses and Dissertations

In this thesis, we present an improved version of Infeasible Interior-Point Method (IIPM) for monotone Linear Complementarity Problem (LCP). One of the most important advantages of this version in compare to old version is that it only requires feasibility steps. In the earlier version, each iteration consisted of one feasibility step and some centering steps (at most three in practice). The improved version guarantees that after one feasibility step, the new iterated point is feasible and close enough to central path. Thus, the centering steps are eliminated. This improvement is based on the Lemma(Roos, 2015). Thanks to this lemma, proximity …

Combinatorial Game Theory: An Introduction To Tree Topplers, John S. Ryals Jr.

Electronic Theses and Dissertations

The purpose of this thesis is to introduce a new game, Tree Topplers, into the field of Combinatorial Game Theory. Before covering the actual material, a brief background of Combinatorial Game Theory is presented, including how to assign advantage values to combinatorial games, as well as information on another, related game known as Domineering. Please note that this document contains color images so please keep that in mind when printing.

Total Synthesis Of Biologically Active Natural And Unnatural Products, Julia Heimberger

Electronic Theses and Dissertations

Herbarin A and B were isolated from the fungal strains of Cladosporium herbarum found in marine sponges Aplysina aerophoba and Callyspongia aerizusa. Total synthesis of Herbarin A and B was achieved by carrying out a multi-step synthesis approach, and the antioxidant properties were evaluated using FRAP assay. Toxicity of these compounds was determined using a zebrafish embryo model. Furthermore, synthesis of C-6 alkyl-azaarene derivatives of nucleosides by Csp3-H bond functionalization were investigated. Effective incorporation of 2-methylazaarene moiety at the C-6 position of the protected inosine nucleoside provided a new class of compounds with anticipated enhanced biological activity.

Bayesian Inference Of The Weibull-Pareto Distribution, James Dow

Electronic Theses and Dissertations

The Weibull distribution has many applications in various topics. Some of these topics include survival analysis, reliability engineering, general insurance, electrical engineering, and industrial engineering. The Weibull distribution was further extended by the Weibull-Pareto distribution. A desirable property this distribution has is its shape can skew being able to better model left or right skewed data. Examples of skewed data include human longevity and actuarial data. In this work a hierarchical Bayesian model was developed using the Weibull-Pareto distribution.

Measurement Of Particulate Transition Metals And Atmospheric Processing Of Iron, Benton T. Cartledge

Electronic Theses and Dissertations

The work presented herein details the measurement of particle-bound metals in environmental samples with specific interests in iron (Fe) in atmospheric particulate matter. Metals were measured in ambient PM_2.5 to study the effects and contributions of a light rail system on the concentrations of metals in atmospheric particles. Particulate matter samples were collected on board trains, near the tracks, and at an urban background location in Denver, CO. Metals were found to be enriched in particles collected on board the trains more so than at the other locations. Fe speciation was also measured in the soluble fraction of the …

Identification Of High Energy Cosmic Ray Electrons Using Advanced Techniques In Calet And Fermi Lat, Aaron James Worley

Electronic Theses and Dissertations

Measurements of the cosmic ray electron spectrum have received much attention over the last decade as anomalies in both electron and positron observations have been detected independently by several experiments. The profound possible implications in the fields of high energy astrophysics and particle physics have allowed for many interpretations on the origin of these inconsistencies in the spectra. This research focuses on two space-borne cosmic radiation experiments at different stages in their mission lifetimes: the Calorimetric Electron Telescope (CALET) and the Fermi Large Area Telescope (LAT). We explore the proton-electron discriminating capabilities of the CALET instrument through Monte Carlo simulations. …

Climate Driven Changes To Malaria Transmission Patterns In Ethiopian Highlands, Amir Said Siraj

Electronic Theses and Dissertations

In the highlands of East Africa, the most populated regions in Africa, temperature is assumed to be intimately connected to the patterns of malaria both in time and space. A large section of the Ethiopian population in this region has historically been shielded from the disease mainly due to the altitudes in the highland regions that have remained free of the disease. However, the region has also seen a large part of its population being affected by malaria in epidemic outbreaks that seem to follow climatic anomalies, especially those of inter-annual increases in temperature. This project examines the inter-annual variability …

Phytoremediation Of Metal Contamination Using Salix (Willows), Gordon J. Kersten

Electronic Theses and Dissertations

Abandoned hardrock mines and the resulting Acid Mine Drainage (AMD) are a source of vast, environmental degradation that are toxic threats to plants, animals, and humans. Cadmium (Cd) and lead (Pb) are metal contaminants often found in AMD. In my mine outwash water samples, cadmium and lead concentrations were 19 and 160 times greater than concentrations in control waterways, and 300 and 40 times greater than EPA Aquatic Life Use water quality standards, respectively. I tested the phytoremediation characteristics of three montane willows native to the Rocky Mountains: Salix drummondiana, S. monticola, and S. planifolia. I tested …

Fluorescent Biological Aerosol Particles In Coastal Canada And The Link To Atmospheric Ice Nuclei, Jixiao Li

Electronic Theses and Dissertations

Bioaerosols are a subgroup of atmospheric aerosols and are often linked to the spread of human, animal and plant diseases. Bioaerosols also may play an indirect effect on environmental processes, including the formation of precipitation and alteration of the global climate through their role as nuclei for cloud droplet formation. Several types of biological organisms (e.g., fungi and bacteria) have been shown to be effective ice nuclei (IN) and cloud condensation nuclei (CCN).

During 21 days in August 2013 we participated in a collaborative international campaign at a rural, coastal site near the village of Ucluelet on the west coast …

Isolation In Synchronized Drone Formations, Andrew P. Brunner

Electronic Theses and Dissertations

This paper expands on a theoretical model that is used for aerial robots that are working cooperatively to complete a task. In certain situations, such as when multiple robots have catastrophic failures, the surviving robots could become isolated so that they never again communicate with another robot. We prove some properties about isolated robots flying in a grid formation, and we present an algorithm that determines how many robots need to fail to isolate at least one robot. Finally, we propose a strategy that eliminates the possibility of isolation altogether.

Complex Vector Lattices: Tensor Products And Multilinear Maps, Christopher Michael Schwanke

Electronic Theses and Dissertations

In this thesis, we study completions of Archimedean real vector lattices relative to any nonempty set of continuous positively homogeneous functions defined on Rn. Examples of such completions include square mean closed vector lattices and geometric mean closed vector lattices. These functional completions lead to a vector lattice complexification of any Archimedean real vector lattice. Unlike the vector space complexification of an Archimedean real vector lattice, the vector lattice complexification always results in an Archimedean complex vector lattice. For example, we prove that the vector space complexification of the Fremlin tensor product C(X)⊗C(Y) is not a complex vector lattice when …

Diagonals Of Tensor Products Of Banach Lattices With Bases., Byunghoon Lee

Electronic Theses and Dissertations

In this dissertation, we investigate diagonals of tensor products of Banach lattices with bases. We first consider questions on the positive tensor products of l_p spaces. We characterize the main diagonals of the positive projective tensor product and the positive injective tensor product of l_p space. Then by using these two main diagonals, we characterize the reflexivity, the property of being Kantorovich - Banach spaces, and the property of being order continuous of n-fold positive projective and positive injective tensor products of l_p spaces. Next, we consider the diagonals of injective tensor product of Banach lattices with bases. Let E …

Electrospun Titanium Dioxide And Silicon Composite Nanofibers For Advanced Lithium Ion Batteries, Kathleen Mccormac

Electronic Theses and Dissertations

A unique electrospinning method was implemented to fabricate composite nanofibers for lithium ion battery applications. The composite nanofibers were made of amorphous carbon, rutile phase TiO₂, and cubic phase Si nanoparticles. Sulfur was utilized as a template to form void structures within the TiO₂ nanofiber matrix. This provides the desired space for the Si expansion during the lithiation process. Phase, structure, composition, and morphology of the nanofibers were characterized using Raman spectroscopy, SEM, EDS, TGA, and powder XRD. Carbonized TiO₂ nanofibers showed a low but stable specific capacity. Si Nanoparticles demonstrated an initially high but fast …

Graphs Of Classroom Networks, Rebecca Holliday

Electronic Theses and Dissertations

In this work, we use the Havel-Hakimi algorithm to visualize data collected from students to investigate classroom networks. The Havel-Hakimi algorithm uses a recursive method to create a simple graph from a graphical degree sequence. In this case, the degree sequence is a representation of the students in a classroom, and we use the number of peers with whom a student studied or collaborated to determine the degree of each. We expand upon the Havel-Hakimi algorithm by coding a program in MATLAB that generates random graphs with the same degree sequence. Then, we run another algorithm to find the isomorphism …

Labeled Trees And Spanning Trees: Computational Discrete Mathematics And Applications, Demet Yalman

Electronic Theses and Dissertations

In this thesis, we examine two topics. In the first part, we consider Leech tree which is a tree of order n with positive integer edge weights such that the weighted distances between pairs of vertices are exactly from 1 to n choose 2. Only five Leech trees are known and some non-existence results have been presented through the years. Variations of Leech trees such as the minimal distinct distance trees and modular Leech trees have been considered in recent years. In this thesis, such Leech-type questions on distances between leaves are studied as well as some other labeling questions …

Solutions Of Inequality Constrained Spline Optimization Problems With The Active Set Method, Joshua A. Holloway

Electronic Theses and Dissertations

We solve the problem of finding a near-interpolant curve, subject to constraints, which minimizes the bending energy of the curve. Using B-splines as our tools, we give a brief overview of spline properties and develop several different cases of inequality constrained optimization problems of this type. In particular, we develop the active set method and use it to solve these problems, emphasizing the fact that this algorithm will converge to a solution in finite iterations. Our solution will solve an open problem regarding near-interpolant spline curves. Furthermore, we supplement this with an iterative technique for better choosing data sites so …

Testing Data Vault-Based Data Warehouse, Connard N. Williams

Electronic Theses and Dissertations

Data warehouse (DW) projects are undertakings that require integration of disparate sources of data, a well-defined mapping of the source data to the reconciled data, and effective Extract, Transform, and Load (ETL) processes. Owing to the complexity of data warehouse projects, great emphasis must be placed on an agile-based approach with properly developed and executed test plans throughout the various stages of designing, developing, and implementing the data warehouse to mitigate against budget overruns, missed deadlines, low customer satisfaction, and outright project failures. Yet, there are often attempts to test the data warehouse exactly like traditional back-end databases and legacy …

Fail-Safe Testing Of Web Applications, Salah Boukhris

Electronic Theses and Dissertations

This dissertation introduces an approach to generate tests to test fail-safe behavior for web applications. We apply the approach to a commercial web application. We build models for both behavioral and mitigation requirements. We create mitigation tests from an existing functional black box test suite by determining failure type and points of failure in the test suite and weaving required mitigation based on weaving rules to generate a test suite that tests proper mitigation of failures. A genetic algorithm (GA) is used to determine points of failure and type of failure that needs to be tested. Mitigation test paths are …

Economic And Traffic Impacts Following The Installation Of New Bicycle Facilities: A Denver Case Study, Stephen Antonio Rijo

Electronic Theses and Dissertations

America is currently experiencing a unique departure from the historical vehicle miles traveled (VMT) trend, often referred to as "peak travel." Decreasing VMT numbers suggest that the US is currently experiencing an unprecedented change in the way individuals utilize transportation systems. The following research calls on a need to understand the importance of improving alternative transportation infrastructure, namely cycling facilities, and how this impacts local businesses and their communities. This research informs the overarching question, "What are the economic and traffic impacts of cycling facilities?" A mixed methods analysis of retail sales tax, traffic count, and RTD transit access data …

Power And Hotspot Modeling For Modern Gpus, Md Mainul Hassan

Electronic Theses and Dissertations

As General Purpose GPUs (GPGPU) are increasingly becoming a prominent component of high performance computing platforms, power and thermal dissipation are getting more attention. The trade-offs among performance, power, and heat must be well modeled and evaluated from the early stage of GPU design. This necessitates a tool that allows GPU architects to quickly and accurately evaluate their design. There are a few models for GPU power but most of them estimate power at a higher level than architecture, which are therefore missing hardware reconfigurability. In this thesis, we propose a framework that models power and heat dissipation at the …

Exploring 3d User Interface Technologies For Improving The Gaming Experience, Arun Kulshreshth

Electronic Theses and Dissertations

3D user interface technologies have the potential to make games more immersive & engaging and thus potentially provide a better user experience to gamers. Although 3D user interface technologies are available for games, it is still unclear how their usage affects game play and if there are any user performance benefits. A systematic study of these technologies in game environments is required to understand how game play is affected and how we can optimize the usage in order to achieve better game play experience. This dissertation seeks to improve the gaming experience by exploring several 3DUI technologies. In this work, …

True Linearized Intensity Modulation For Photonic Analog To Digital Conversion Using An Injection-Locked Mode-Locked Laser, Edris Sarailou

Electronic Theses and Dissertations

A true linearized interferometric intensity modulator for pulsed light has been proposed and experimentally presented in this thesis. This has been achieved by introducing a mode-locked laser into one of the arms of a Mach-Zehnder interferometer and injection-locking it to the input light (which is pulsed and periodic). By modulating the injection-locked laser, and combining its output light with the light from the other arm of interferometer in quadrature, one can achieve true linearized intensity modulator. This linearity comes from the arcsine phase response of the injection-locked mode-locked laser (as suggested by steady-state solution of Adler's equation) when it is …

Electronic Transport Properties Of Carbon Nanotubes: The Impact Of Atomic Charged Impurities, Ryuichi Tsuchikawa

Electronic Theses and Dissertations

Even changing one atom in nanoscale materials is expected to alter their properties due to their small physical sizes. Such sensitivity can be utilized to modify materials' properties from bottom up and is essential for the utility of nanoscale materials. As such, the impact of extrinsic atomic adsorbates was measured on pristine graphene and a network of carbon nanotubes using atomic hydrogen, cesium atoms, and dye molecules. In order to further quantify such an atomic influence, the resistance induced by a single potassium atom on metallic and semiconducting carbon nanotubes was measured for the first time. Carbon nanotubes are sensitive …

Providing Context To The Clues: Recovery And Reliability Of Location Data From Android Devices, Connie Bell

Electronic Theses and Dissertations

Mobile device data continues to increase in significance in both civil and criminal investigations. Location data is often of particular interest. To date, research has established that the devices are location aware, incorporate a variety of resources to obtain location information, and cache the information in various ways. However, a review of the existing research suggests varying degrees of reliability of any such recovered location data. In an effort to clarify the issue, this project offers case studies of multiple Android mobile devices utilized in controlled conditions with known settings and applications in documented locations. The study uses data recovered …

The Design, Implementation, And Refinement Of Wait-Free Algorithms And Containers, Steven Feldman

Electronic Theses and Dissertations

My research has been on the development of concurrent algorithms for shared memory systems that provide guarantees of progress. Research into such algorithms is important to developers implementing applications on mission critical and time sensitive systems. These guarantees of progress provide safety properties and freedom from many hazards, such as dead-lock, live-lock, and thread starvation. In addition to the safety concerns, the fine-grained synchronization used in implementing these algorithms promises to provide scalable performance in massively parallel systems. My research has resulted in the development of wait-free versions of the stack, hash map, ring buffer, vector, and a multi-word compare-and-swap …

Vanadium Oxide Microbolometers With Patterned Gold Black Or Plasmonic Resonant Absorbers, Evan Smith

Electronic Theses and Dissertations

High sensitivity uncooled microbolometers are necessary to meet the needs of the next generation of infrared detectors, which seek low power consumption and production cost without sacrificing performance. Presented here is the design, fabrication, and characterization of a microbolometer with responsivity enhanced by novel highly absorptive coatings. The device utilizes a gold-doped vanadium oxide film in a standard air bridge design. Performance estimations are calculated from current theory, and efforts to maximize signal to noise ratio are shown and evaluated. Most notably, presented are the experimental results and analysis from the integration of two different absorptive coatings: a patterned gold …

Density-Functional Theory+Dynamical Mean-Field Theory Study Of The Magnetic Properties Of Transition-Metal Nanostructures, Alamgir Kabir

Electronic Theses and Dissertations

In this thesis, Density Functional Theory (DFT) and Dynamical Mean-Field Theory (DMFT) approaches are applied to study the magnetic properties of transition metal nanosystems of different sizes and compositions. In particular, in order to take into account dynamical electron correlation effects (time-resolved local charge interactions), we have adopted the DFT+DMFT formalism and made it suitable for application to nanostructures. Preliminary application of this DFT+DMFT approach, using available codes, to study the magnetic properties of small (2 to 5-atom) Fe and FePt clusters provide meaningful results: dynamical effects lead to a reduction of the cluster magnetic moment as compared to that …

Photophysics Of Organic Probes And Their Applications In Bioimaging & Photodynamic Therapy, Bosung Kim

Electronic Theses and Dissertations

Over the past several decades the phenomenon of luminescence (divided into fluorescence and phosphorescence) has received great attention in the field of biological science. This quest has motivated scientists for a variety of applications, including fluorescence imaging. Fluorescence microscopy techniques that provide unique advantages, such as high spatial resolution and superior sensitivity, have been regarded as attractive tools in biophotonics. With the progress of ultrafast laser sources, two-photon absorption (2PA), in which a molecule absorbs two photons simultaneously, has opened possibilities of using it for various applications. Two-photon fluorescence microscopy (2PFM), which affords deeper tissue penetration and excellent three-dimensional (3D) …