Digital Commons Network^™

Experimental And Numerical Analysis Of Less-Mobile Domain Processes In Naturally Occurring Porous Media, Farzaneh Mahmood Poor Dehkordy

Doctoral Dissertations

The importance of the exchange between surface water (SW) and groundwater (GW) is well known among researchers because of its effects on multiple processes including contaminant transport, biogeochemical reactions, and remediation techniques. Thorough understanding of this exchange can be challenging due to the various factors that can impact GW-SW exchange dynamics; especially considering the possibility of sediment heterogeneity in porous media. In the presence of sediment heterogeneity, pores with different levels of connectivity are expected. Pores that are well connected create “mobile” zones, while poorly connected pores create “less-mobile” zones. Conventional fluid sampling techniques are primarily sensitive to the mobile …

Investigating Students' Mathematical Needs And Successful Tutoring Strategies, Melissa Newell

Doctoral Dissertations

Quantitative learning centers (QLCs) have emerged on undergraduate around the globe in an attempt to provide necessary support to students enrolled in undergraduate courses that address quantitative literacy. QLCs often provide support through peer tutoring to students in mathematics or related courses. Since QLCs are prevalent on undergraduate campuses and have the potential to impact students from diverse backgrounds and disciplines, it is pertinent that we understand their effects on the learning experience. In the existing literature, QLCs are shown to have an overall positive impact on students both academically and affectively, however studies rarely investigate the needs of the …

Modulating Antitumor T Cell Responses Using Cytomegalovirus-Based Vaccines, Jeremy Grenier

Doctoral Dissertations

Cytomegalovirus (CMV) is a ubiquitous herpes virus that generates a unique T cell response, characterized by the maintenance of a high frequency of virus-specific T cells over the lifetime of the host. This prolonged T cell response makes CMV an attractive vaccine platform. Our lab has previously generated a recombinant murine CMV (MCMV) expressing a modified melanoma antigen, MCMVgp100KGP, which protects mice from tumor challenge. In Chapter 3 of this current study, we hypothesized that CMV vectors expressing multiple tumor antigens would be more effective vaccines in the treatment of melanoma. However, our data show that novel MCMV vectors expressing …

Prediction Of Supersaturation From Amorphous Drugs And Mechanisms Of Crystallization Inhibition From Supersaturated Solutions, Arushi Manchanda

Doctoral Dissertations

Supersaturating drug delivery systems, especially amorphous formulations, are used to achieve higher oral bioavailability for poorly soluble drugs. However, amorphous formulations, being thermodynamically unstable, recrystallizes upon contact with water, making experimental measurement of amorphous solubility enhancement challenging. In this work, factors affecting the re-crystallization of poorly soluble drugs and amorphous solubility enhancement were studied.

The various approaches in the literature employed in the calculation of amorphous solubility enhancement ratio (R_s) were compared and moreover, the nuances associated with the estimation of R_s, were also explored. Based on the sensitivity and error analysis on the calculated value …

Predicting Weather-Caused Power Outages: Technique Development, Evaluation, Applications, Diego Cerrai

Doctoral Dissertations

Storms are the primary cause of extensive power outages in electric distribution networks. Storm power outage prediction is therefore fundamental for an efficient and effective response to weather-based power outages. In this work, we address the problem of storm outage prediction by improving an existing outage prediction model (OPM) originally developed for thunderstorm and extratropical storms, and extending its structure for predicting outages associated with mixed phase precipitation (snow, ice, freezing rain) events. The herein developed OPMs use either regression trees or statistical models fed by numerical weather prediction outputs, leaf area index (LAI), infrastructure, land cover, soil type, elevation, …

Overcoming Long Reconstitution Times Of High Concentration Lyophilized Protein Formulations, Shreya Shashank Kulkarni

Doctoral Dissertations

Highly concentrated therapeutic protein products stabilized by lyophilization often have undesirably long and variable reconstitution times. The overall objective of this work was to identify factors governing the reconstitution times of these formulations. Fundamental understanding of these factors will reduce the barrier to efficient formulation and process design presented by poorly reconstituting drug products.

Properties of the lyophilized “cake” that have been previously implicated in influencing reconstitution are cake wettability, liquid penetration into cake, cake disintegration, and cake porous structure. Methods to quantify these properties of intact cakes in vials were refined and further developed. The effects of formulation and …

Optoelectronic Interactions Of Quantum Dots With Gold Nanoparticles And Bacteriorhodopsin, Terianna Wax

Doctoral Dissertations

Over the past two decades, there has been a burgeoning interest in the use of nanomaterials for device applications due to these systems displaying unique optoelectronic properties that are not seen on the bulk scale. One branch of nanostructures that has garnered attention is the field of quantum dots (QDs), which are nanoscale semiconductors that can absorb a broad, spectral range of light. Compared to traditionally used organic fluorophores, QDs exhibit numerous advantageous properties, such as high photostability, narrow emission peaks, and size tunability. There have been a profusion of studies exploring the interface between QDs with both inorganic and …

Inferring Microbial Gene Family Evolution Using Duplication-Transfer-Loss Reconciliation: Algorithms And Complexity, Misagh Kordi

Doctoral Dissertations

Gene families evolve through complex evolutionary events such as speciation, gene duplication, horizontal gene transfer, gene loss, etc., and reconstructing these evolutionary histories is an important problem in evolutionary biology with many important applications. Duplication-Transfer-Loss (DTL) reconciliation is among the most effective and most popular methods for studying gene family evolution, especially in microbes. DTL reconciliation takes as input a gene tree and a species tree and reconciles the two by postulating gene duplication, transfer, and loss events, showing the evolution of that gene family inside the species tree. The DTL reconciliation problem has been extensively studied, but existing problem …

Towards Layerless Printing In Additive Manufacturing, Radu Ioan Corcodel

Doctoral Dissertations

In recent years, Additive Manufacturing (AM) has advanced from its ubiquitous function of design validation to biomedical and biomimetic engineering, rapid tooling, tissue engineering, the arts and even food manufacturing. Though the corresponding scale reduction of the manufactured models did not coincide with improving two of the most important process characteristics, namely print accuracy and build time. This research aims to formulate a computational framework for computing the maximum build volume for given non-circular aperture extruders and printing machines that have 3, or perhaps higher numbers of degrees of freedom (DoF), and also generate suitable print head motions given heuristic …

Full-Scale Evaluation Of A Novel Repair For Corroded Plate Girders With Uhpc, Kevin F. Mcmullen

Doctoral Dissertations

Corrosion damage of girder ends is a prevalent problem throughout the United States. Heavy section loss is often located beneath leaking expansion joints, which deposits water and chlorides on the girders and accelerates corrosion. Section loss at these critical locations may be detrimental to the bearing capacity of the girder. Current repair methods are costly, time consuming, and disruptive to traffic. A new repair method has been developed by the University of Connecticut and the Connecticut Department of Transportation for corroded steel bridge girder ends. The proposed repair method consists of encasing the corroded steel area with ultra-high performance concrete …

Characterization Of Graphene Oxide, Harish Kumar

Doctoral Dissertations

The conversion of graphite to graphene oxide (GO) is an effective and widely used method for solubilizing and exfoliating graphite. However, the oxidation is not uniform, and wide variations in the degree of oxidation exist between and within batches of GO. In this dissertation, we introduce an approach to both quantify the global degree of oxidation in GO and to separate GO into fractions, each with more uniform extents of oxidation. Using the formation of GO-stabilized oil-in-water emulsions, GO is separated into an emulsion fraction and a water fraction. The results find that the GO sheets that stabilize the emulsion …

Marriage And Family Therapist Websites: A Qualitative Content Analysis, Thomas Bischoff

Doctoral Dissertations

The positive benefits of therapy are well-established (Duberstein et al., 2018) and therapy continues to make significant strides with regard to therapeutic outcomes. However, little is known regarding client initiation processes as well as how therapists reach out to potential clients. Clients present with a variety of challenges, and researchers and clinicians struggle with creating ways to increase access to care, reach out to potential clients, and engage individuals in therapy services. Nevertheless, therapist engagement and connection with the client can have a significant impact (Sexton, Littauer, Sexton, & Tømmerås, 2005). Marriage and Family Therapists (MFTs) are uniquely trained and …

Study Of Large Scale Hybrid Concrete-Filled Fiber Reinforced Polymer Tube Columns (Hcffts), Alexandra Hain

Doctoral Dissertations

Archival abstract submitted

Design Of Transition Metal Oxide And Phosphide Nanomaterials: Their Catalytic Activities, Md Mahbubur Rahman Shakil

Doctoral Dissertations

This thesis is focused on developing transition metal-based oxide and phosphide nanomaterials for catalytic application in energy conversion and the organic transformation reaction. The research projects presented in this thesis are: (1) the design and synthesis of transition metal doped ZnO catalysts for the oxygen reduction reaction (ORR), (2) the development of mesoporous FeP and CoP materials as hydrogen evolution reaction (HER) catalysts for electrochemical water splitting, and (3) the fabrication of different ZnO morphologies for coumarin synthesis by the Knoevenagel condensation.

The first chapter describes the significance and background of the three research projects. We emphasize the current challenges …

Modeling Of The Axon Plasma Membrane With The Effect Of Cytoskeleton On Its Membrane Protein Diffusion, Yihao Zhang

Doctoral Dissertations

Here, we used the coarse-grain molecular dynamics (CGMD) method to establish a simulation model for the axon plasma membrane (APM) that was then used to study the mechanical properties of the APM and to investigate how the axon plasma membrane skeleton (APMS) affects diffusion of membrane proteins in the axon. Super-resolution microscopy has illustrated that the APMS consists of periodic actin ring-like structures along its length connected by spectrin tetramers and anchored to the lipid bilayer via ankyrin. Based on these experimental results, we developed a CGMD model for the APMS. In particular, the model comprises representations of periodic actin …

An Integrated Framework For Domain, Gene And Species Reconciliation, Lei Li

Doctoral Dissertations

Genes, as functional fragments of DNA sequences, evolve inside genomes through evolutionary events such as gene duplication, gene loss, and horizontal gene transfer. These evolutionary events are often assumed to affect entire genes, rather than parts of genes. However, it is well understood that a majority of genes in eukaryotes consist of multiple protein domains that can be independently lost or gained during evolution. Despite the fact that a large amount of research has been conducted on protein domains, existing research generally focuses on detecting domains and on studying the domain content of genes. Thus, the study of domain evolution …

Regulation Of Sickle Cell Disease Specific Erythrocyte Adhesion, Jing Zhang

Doctoral Dissertations

Human red blood cells (RBCs) provide essential gaseous exchanges to all body’s tissues and organs through the circulatory system. RBCs lack of nucleus and organelles provides as much room as possible for the oxygen-carrying protein hemoglobin. Hemoglobin composes ~98% of the soluble proteins in mature RBCs. RBCs have a biconcave shape corresponding to a large cellular surface area-to-volume ratio allowing for efficient gas exchange and increased cell deformability ensuring passage through the narrowest capillaries without rupturing and vessel obstruction. In sickle cell disease (SCD), a single point mutation occurs in the beta-globin gene, resulting in the production of abnormal hemoglobin …

Strategies For The Synthesis Of Glycosylated Small Molecule Libraries And New Bioactive Compounds, Zachary Cannone

Doctoral Dissertations

The synthesis of glycosylated small molecule compound libraries remains a difficult challenge in the field of organic chemistry. Leading techniques are hindered by the requirement of optimization based on substrate, and the generation of non-classical glycoside products. The development of a platform which takes advanced glycoside intermediates and utilizes reactive handles on the aglycone for rapid diversification to final products has been completed in this research. Use of amino sugars, derived from known antibiotics, as the carbohydrate component of final compounds was intended to exploit known binding interactions with biomacromolecules. Final compounds indeed showed ability to inhibit bacterial protein synthesis …

Methods In Studying Red Blood Cells In Sickle Cell Disease, Kostyantyn Partola

Doctoral Dissertations

Sickle cell disease (SCD) is a genetically inherited blood disorder characterized by a single point mutation that produces hemoglobin S within red blood cells (RBCs). When such RBCs are deoxygenated hemoglobin S polymerizes and causes the cells to take on a sickle shape and become more viscous and stiffer than normal RBCs. The hallmark of SCD is painful vaso-occlusive crises in which the flow of blood to parts of the body is obstructed. Today, millions of people suffer from SCD around the world and life expectancy of individuals with SCD is in the 40’s. We developed several techniques to facilitate …

Cyber-Physical Networked Microgrids, Yan Li

Doctoral Dissertations

Power grid stability and security are challenging problems with significant economic and social impacts that have been exacerbated in recent years by the increase in extreme weather events and cyberattack concerns. Recently, networked microgrids (NMs) have become an emerging paradigm that demonstrates resiliency benefit to their local customers. U.S. DOE has envisioned that the R\&D of NMs will be the next wave of smart grid research to achieve the nation's grid modernization vision towards climate adaptation and resiliency. However, lack of awareness of stability margin, inadequate capability to respond to grid disturbances, and vulnerabilities to communication failure, delay, and cyberattacks …

Coverage And Time-Optimal Motion Planning For Autonomous Vehicles, Junnan Song

Doctoral Dissertations

Autonomous vehicles are rapidly advancing with a variety of applications, such as area surveillance, environment mapping, and intelligent transportation. These applications require coverage and/or time-optimal motion planning, where the major challenges include uncertainties in the environment, motion constraints of vehicles, limited energy resources and potential failures. While dealing with these challenges in various capacities, this dissertation addresses three fundamental motion planning problems: (1) single-robot complete coverage in unknown environment, (2) multi-robot resilient and efficient coverage in unknown environment, and (3) time-optimal risk-aware motion planning for curvature-constrained vehicles.

First, the ε* algorithm is developed for online coverage path planning in unknown …

Memory Access Efficiency In Distributed Atomic Object Implementations, Theophanis Hadjistasi

Doctoral Dissertations

Distributed data services use redundancy to ensure data availability and survivability. Replication can be used to mask failures, however it introduces the problem of consistency because operations may access different object replicas, possibly containing obsolete values. Atomicity is a venerable notion of consistency, introduced in 1979 by Lamport. Atomicity is the most natural type of consistency because it provides an illusion of equivalence with the serial object type that software designers expect.

We deal with the storage of atomic shared readable and writable data in distributed systems that are subject to perturbations in the underlying distributed platforms composed of computers …

Energy Flow Regulation Through Built-Up Structures Toward Wave Guiding And Vibration Damping, Shilong Li

Doctoral Dissertations

The overarching goal of structural dynamic analysis is usually to facilitate regulation of energy flows in terms of vibration and acoustic wave transmission. Such regulation of vibratory energy flows can yield effective designs of vibration suppression, energy harvesting, and vibration/wave based health monitoring, etc. This dissertation research employs the concept of built-up structure, i.e., constructing secondary oscillatory sub-systems and incorporating them into the underlying host structure to realize new ways of energy flow regulation. In particular, we propose to develop three distinct designs of sub-systems to realize unusual wave transmission and to dramatically improve damping performance, i.e., electro-mechanical local scatter …

Exploiting Phase Change Memory Nano-Device Properties For Hardware Security Applications, Nafisa Noor

Doctoral Dissertations

Security has become a crucial concern in hardware design due to the growing need of protection in everyday financial transactions and exchanges of private information. Physical unclonable functions (PUFs) utilize the inevitable process variations and other stochastic properties in devices to provide a unique way to verify trusted users during access to hardware devices. Improvements in attack methods have recently moved the field of PUFs from traditional silicon devices toward emerging non-volatile memories, such as phase change memory (PCM). Due to intrinsic cell-to-cell and cycle-to-cycle programming variability and high endurance properties of PCM nano-devices, unpredictable and reconfigurable PUF challenge-response pairs …

Biopolymer-Nanotube Nerve Guidance Conduit Drug Delivery For Peripheral Nerve Regeneration, Ohan S. Manoukian

Doctoral Dissertations

Peripheral nerve injuries account for roughly 3% of all trauma patients with over 900,000 repair procedures annually in the U.S. Of all extremity peripheral nerve injuries, 51% require nerve repair with a transected gap. The current gold-standard autograft repair has several associated shortcomings, while engineered constructs typically offer suboptimal results only suitable for short gaps. In order to achieve enhanced peripheral nerve regeneration and greater functional recovery, we have developed a biodegradable, chitosan-based nerve guidance conduit (NGC) with aligned microchannel porosity and halloysite nanotubes for the sustained release of 4-Aminopyridine (4AP), a small molecule drug that promotes nerve conduction and …

High Temperature Non-Equilibrium Non-Isothermal Semiconductor Modeling, Sadid Muneer

Doctoral Dissertations

Under extreme thermal gradients (~> 1 K/nm) significant asymmetric melting of current-carrying highly-doped silicon micro-wires was observed. This bizarre phenomenon was explained by the generation-transport-recombination (GTR) process of the minority carriers in semiconductors at elevated temperatures. The finite element simulation model, using effective media approximation, supported this explanation; however, the asymmetry observed in the experiments is significantly larger than that obtained from the computational results. As the calculation based on conventional non-isothermal semiconductor physics underestimates the exponential growth of carrier generation near melting, the carrier concentration, hence the shift of the hottest spot because of the thermoelectric Thomson effect, was …

Multi-Layered Paper-Based Microfluidic Platform For Point-Of-Care Male Fertility Test, Reza Amin

Doctoral Dissertations

Archival abstract submitted

Mesoscale Modeling Of Defect And Damage Evolution In Lightweight Metallic Materials Under Shock Loading Conditions, Garvit Agarwal

Doctoral Dissertations

The capability to predict the impact tolerance of next generation lightweight metallic materials for protective armor application requires fundamental understanding of the deformation and failure behavior of these materials under dynamic loading conditions. Loading conditions of impact/shock result in complex stress states that range from uniaxial compression to tension at high strain rates ranging from 10⁵ s^-1 to 10¹⁰s^-1. The deformation response of these materials is determined by the capability of the microstructures to nucleate dislocations and failure response is determined by the creation of weak sites for void nucleation during uniaxial expansion. A …

Development Of An Astrocyte/Glioma Co-Culture System For Measuring Cellular Dynamics, Urna Kansakar

Doctoral Dissertations

Gliomas are brain tumors that primarily arise from glial cells. Gliomas account for 70% of the brain tumors and they are more prevalent in older adults. About 60% of the people with gliomas experience at least one seizure. Brain tumors can grow and metastasize to neighboring areas, thereby destroying normal brain cells. In a brain tumor microenvironment, both malignant cancer cells and healthy brain cells are present. Studies have shown that astrocytes may have a role in tumor growth in the brain. Monocultures cannot evaluate interactions between two cell types and does not accurately represent in vivo conditions. Thus, a …

Development Of A Counter-Flow Thermal Gradient Microfluidic Device, Shayan Davani

Doctoral Dissertations

This work presents a novel counter-flow design for thermal stabilization of microfluidic thermal reactors. In these reactors, precise control of temperature of the liquid sample is achieved by moving the liquid sample through the thermal zones established ideally through the conduction in the solid material of the device. The goal here is to establish a linear thermal distribution when there is no flow and to minimize the temperature change at flow condition. External convection as well as internal flowinduced effects influence the prescribed thermal distribution. The counter-flow thermal gradient device developed in this study is capable of both stabilizing the …