Digital Commons Network^™

Process Intensification Through Spherical Crystallization: Novel Experimental And Modeling Approaches, Ramon Peña

Open Access Dissertations

Process intensification is defined as the use of innovative techniques and technologies to create sustainable solutions to industrial production difficulties. Continuous spherical crystallization is a process intensification technique that could resolve production issues for pharmaceutical and solids processing industries, consequently, allowing for the integration of upstream and downstream manufacturing units. Spherical crystallization is carried out through emulsion based crystallization and/or agglomeration in suspension of fine crystals to produce aggregates of improved bulk and micromeritic properties. The advantages of spherical crystallization include: (i) replacing downstream particle correction units (i.e., milling, granulation), (ii) providing control of crystalline properties by decoupling crystallization and …

Determining Variation In Virulence, Persistence, And Stress Tolerance Among Salmonella Enterica And Listeria Monocytogenes From Food And Food-Associated Environments, Andrea J. (Ray) Etter

Open Access Dissertations

The U.S. food industry employs multiple strategies to prevent foodborne illness including the use of antimicrobials, sanitizers, and heat to reduce or eliminate pathogens in food products. However, Listeria monocytogenes and Salmonella enterica isolates have widely varying tolerance to common processing stresses. Additionally, both pathogens display considerable variation in virulence among serovars and strains. The goal of these studies was to characterize the range of virulence and persistence capabilities for L. monocytogenes and S. enterica isolates. To this end, we determined the prevalence of inlA mutations in L. monocytogenes collected from retail deli surfaces, and used PFGE to study the …

Anisotropic Electron-Electron Interactions In Topological Insulators, Marius A. Radu

Open Access Dissertations

HgTe forms a two-dimensional topological insulator when sandwiched between CdTe barriers for a HgTe layer wider than the critical thickness. In this study we derive single-particle interaction Hamiltonians describing the physics of these compounds by using k · p theory and extended Kane model. We include contributions from upper conduction bands with orbital states of p-symmetry that bring about the terms describing lack of inversion symmetry in host semiconductors. A crucial ingredient is hetero-interface contribution to intrinsic spin-orbit interactions that drives significant anticrossing gaps in spectra at zero wavevector, but results in a circle of spectral degeneracies at finite wavevectors. …

Novel Strategies For The Multi-Level, Online Optimization And Control Of Batch Operations Under Uncertainty, Francesco Rossi

Open Access Dissertations

This thesis is focused on the development and application of innovative methods and algorithms for the multi-level, online optimization and control of batch processes under uncertainty. Specifically, it proposes novel solutions for the deterministic and stochastic dynamic optimization/optimal control of single batch operations and introduces new strategies for the integrated scheduling, dynamic optimization and optimal control of multi-unit/multi-step batch process. Moreover, it develops innovative approaches for the rapid estimation of the probability distribution of the uncertain parameters of dynamic process models from experimental measurements as well as new methodologies for selection of the optimal set of uncertain parameters in stochastic …

A General Probabilistic Framework Combining Experiments And Simulations To Identify The Small Crack Driving Force, Andrea Rovinelli

Open Access Dissertations

Identifying the small fatigue crack (SFC) driving force of polycrystalline engineering alloys is instrumental in correlating the inherent microstructure variability and the scatter exhibited by SFC during the early stage of propagation. By utilizing synchrotron images of a SFC propagating through a beta-metastable titanium alloy a general framework to identify the SFC driving force is presented. FFT-based crystal plasticity simulations are then used to computed micromechanical quantities not available from the experiment. The experimental and simulation results are consolidated into a multimodal dataset which is sampled using physically based nonlocal data mining techniques. Sampled data are analyzed via a machine …

Two Mathematics Teachers' Personal Practical Knowledge: Experiences Making Curriculum Within The 3d Inquiry Space, Elizabeth Suazo Flores

Open Access Dissertations

This study is an effort to expand conceptualizations of mathematics teachers’ knowledge where teachers’ experiences are considered an important source of their knowledge. Using Schwab’s (1969, 1983) concept of curriculum and Dewey’s (1938) theory of experience as theoretical lenses, the researcher, a former secondary mathematics teacher, explored an eighth-grade mathematics teacher’s personal practical knowledge ([PPK], Elbaz, 1981, 1983). The mathematics aspect of this study was the emerging concept of area as students worked on a lesson involving real-world context. Field and research texts were constructed through narrative inquiry (Clandinin & Connelly, 2000). This study illustrates how under a four-year collaboration: …

New Multi-Harmonic Techniques For Sensing Tip-Sample Interactions And Nanomechanical Material Property Mapping In Dynamic Atomic Force Microscopy, Nurul Huda Shaik

Open Access Dissertations

The Atomic Force Microscope (AFM) is a versatile tool for studying and characterizing materials at the micro-and nano-scales. The microcantilever designs used in AFM, as well as the experimental and theoretical approaches for quantitative material characterization, are now well developed and understood. However, there are still certain experimental conditions where the conventional design of these probes and the existing material characterization methods limit the applicability of the tool. The challenges associated with the probe design are addressed by integrating additional degrees of freedom into these probes that enabled modification of the eigen-structure of the probes as desired. Designing, fabricating and …

Global Optimization Approach To The Labeling Of Airborne Lidar Point Clouds, Serkan Ural

Open Access Dissertations

Airborne LiDAR systems provide an unstructured 3D sampling of the objects on and above the ground. Building extraction has traditionally been among the most sought-after applications of airborne lidar topographic mapping along with digital elevation model generation. Extracting buildings from point clouds requires the labeling of the point cloud. Recent methods take advantage of the point properties calculated within a local neighborhood to achieve such labeling. Considering only the properties of individual points however, disregards spatial coherence. The relative change of point properties in the immediate surrounding of each point as well as spatial relationships between neighboring points need to …

Coherent Radiation In Atomic Systems, Robert Tyler Sutherland

Open Access Dissertations

Over the last century, quantum mechanics has dramatically altered our understanding of light and matter. Impressively, exploring the relationship between the two continues to provide important insights into the physics of many-body systems. In this thesis, we add to this still growing field of study. Specifically, we discuss superradiant line-broadening and cooperative dipole-dipole interactions for cold atom clouds in the linear-optics regime. We then discuss how coherent radiation changes both the photon scattering properties and the excitation distribution of atomic arrays. After that, we explore the nature of superradiance in in intially inverted clouds of multi-level atoms. Finally, we explore …

Micromechanics Based Failure Analysis Of Heterogeneous Materials, Hamsasew M. Sertse

Open Access Dissertations

In recent decades, heterogeneous materials are extensively used in various industries such as aerospace, defense, automotive and others due to their desirable specific properties and excellent capability of accumulating damage. Despite their wide use, there are numerous challenges associated with the application of these materials. One of the main challenges is lack of accurate tools to predict the initiation, progression and final failure of these materials under various thermomechanical loading conditions. Although failure is usually treated at the macro and meso-scale level, the initiation and growth of failure is a complex phenomena across multiple scales. The objective of this work …

Computational And Theoretical Study Of The Physical Constraints On Chemotaxis, Julien Varennes

Open Access Dissertations

Cell chemotaxis is crucial to many biological functions including development, wound healing, and cancer metastasis. Chemotaxis is the process in which cells migrate in response to chemical concentration gradients. Recent experiments show that cells are capable of detecting shallow gradients as small as a 1% concentration difference, and multicellular groups can improve on this by an additional order of magnitude. Examples from morphogenesis and metastasis demonstrate collective response to gradients equivalent to a 1 molecule difference in concentration across a cell body. While the physical constraints to cell gradient sensing are well understood, how the sensory information leads to cell …

Autonomous Guidance Strategy For Spacecraft Formations And Reconfiguration Maneuvers, Theodore P. Wahl

Open Access Dissertations

A guidance strategy for autonomous spacecraft formation reconfiguration maneuvers is presented. The guidance strategy is presented as an algorithm that solves the linked assignment and delivery problems. The assignment problem is the task of assigning the member spacecraft of the formation to their new positions in the desired formation geometry. The guidance algorithm uses an auction process (also called an “auction algorithm”), presented in the dissertation, to solve the assignment problem. The auction uses the estimated maneuver and time of flight costs between the spacecraft and targets to create assignments which minimize a specific “expense” function for the formation. The …

Clustering And Segmentation With Application In Document Image Processing, Haitao Xue

Open Access Dissertations

In this dissertation, we introduce a set of algorithms for document image processing, which are in the research area of color clustering and binarization. Color quantization algorithms are used to select a small number of colors that can accurately represent the content of a particular image. In this research, we introduce a novel color quantization algorithm which is based on the minimization of a modifed Lp norm rather than the more traditional L2 norm associated with mean square error (MSE) [1]. We demonstrate that the Lp optimization approach has two advantages. First, it produces more accurate perceived quality results, especially …

Optimization, Control And Operation Strategies For Distributed Energy Systems, Jie Xue

Open Access Dissertations

In this dissertation, the problem of optimal operation strategies and control for gas turbine based distributed energy systems (DES) is addressed using mathematical optimization methods and computational intelligence techniques. Detailed mathematical component models for the key components of the DES such as gas turbine power generator, heat exchanger, absorption chiller, photovoltaic and wind turbine, are developed to capture the important behavior of these components and their interactions with the overall DES. These models are used to develop integrated DES models for the purpose of optimization and control design. A multi-objective function considering the total system efficiency and operational cost is …

Damage, Tension/Compression Asymmetry And Inferred Crack Growth In Fatigue Title Of Aluminum Alloys, Colin Young

Open Access Dissertations

The idea of a quantity D, which tracks the damage state of a material from 0 (virgin) to 1 (failed) is a well-established concept. In fatigue tests, where a given load cycle is repeated until failure, it is common to define damage D per cycle as the fraction of total life consumed per cycle, or 1/Nf. We begin by using Maximum Entropy method to develop a curve to model the life vs. load cycle relationship for a wrought aluminum alloy 2024-T351 in the low cycle fatigue range. The approach is novel in that the loading is described in terms in …

Augmented Matrix Solvers For Dynamic Linear Systems Of Equations, Yu Hong Yeung

Open Access Dissertations

In this dissertation, the problem of updating in real time the solution to a linear system of equations when a sequence of small changes is made to the data is considered. This problem arises in many computational science and engineering applications, and we consider two of them. The first is surgical simulations, where a simulator used to train surgeons needs to provide haptic feedback by updating the system ten to hundred times per second. The second is contingency analysis in the power grids, when their operators need to simulate a large number of scenarios to predict what could happen when …

Scalable Bayesian Nonparametrics And Sparse Learning For Hidden Relationship Discovery, Shandian Zhe

Open Access Dissertations

Real-world data often encompass hidden relationships, such as interactions between modes in multidimensional arrays (or tensors), subsets of features correlated to specifc responses, and associations between heterogeneous data sources. Uncovering these relationships is a key problem in machine learning and data mining, and relates to numerous applications ranging from information security to imaging genetics and to computational advertisement. However, to mine these relationships, we have to face several signifcant challenges. First, how can we design powerful models to capture the complicated, potentially highly nonlinear patterns in data? Second, how can we develop effcient model estimation algorithms to deal with real-world …

A Proposal To Change Sentencing Appeals In Arkansas, Anthony L. Mcmullen

University of Arkansas at Little Rock Law Review

No abstract provided.

Performance Evaluation Of Mission Critical Communications Services Over Lte Networks, Kehinde Olumide Olasupo

Theses and Dissertations

he existing Private/Professional Mobile Radio (PMR) technologies designed specifically for Mission Critical Communication (MCC) systems are narrowband and wideband devices, with limited network data capacity in emergency scenarios. They are majorly used to support MCC voice communications and low data rate applications during mission critical operations. However, the need for broadband systems that would support high radio data capacity keep increasing during major incidents and accident scenarios. Because of this, the MCC agencies were attracted by the broadband capabilities of Long Term Evolution (LTE) technology. But, the uplink capacity of LTE- based MCC systems is still a concern. In planning …

Ensuring Student Success In Full-Day Kindergarten: Purposeful Professional Development And Professional Learning Communities, Amy Houlihan

Dissertations

The change leadership model, developed by Wagner et al. (2008), was utilized to assess the context, culture, conditions and competencies of a large suburban school district during the early stages of districtwide implementation of full-day kindergarten. With overwhelming support from families, teachers and administrators, the change plan revolves around ongoing and purposeful professional development for staff building upon systematic work of Professional Learning Communities in order to provide a high quality full-day kindergarten program across twenty-three kindergarten program sites. When districts and schools focus on purposeful professional development and enhanced practice of Professional Learning Communities programs can work to provide …

Transforming The American Education System: A Program Evaluation Of A School District’S 1:1 Chromebook Pilot, Michael Marassa

Dissertations

The focus of this program evaluation is to determine the impact of a Google Chromebook 1:1 program on the learning process and educational experience for students and teachers. The participants attend two high schools of a high-performing public-school district in an affluent Chicago suburb. The following research questions guide the program evaluation:

• What is the measurable relationship between academic performance and engagement and the 1:1 Chromebook program?
• What changes in instructional practice occur with the implementation of 1:1 Chromebooks?

A literature review presents current research in areas that explore 21st Century Skills, Tony Wagner’s Global Achievement Gap, constructivist instructional pedagogy, …

Popularity Prediction, Andrew Furgiuele

Computer Science

With the rise in popularity of the Internet, data describing unique types of items has been collected into easy to access sources. Using this newly acquired data, is it possible to predict if an item will become a bestseller while another fade away with time? Popularity prediction is a problem that has attracted a great deal of research recently, and for good reason. The ability to predict an items future rise to popularity or fall to obscurity is a possibly priceless skill and sought out in many different industries such as sales, investments, and marketing. This report enumerates and analyzes …

Biological Condition Of Money Pont Benthic Communities, Southern Branch Of The Elizabeth River (2010, 2013, 2016), Daniel M. Dauer

Elizabeth River Reports

Executive Summary

This report summarizes the ecological condition of the subtidal macrobenthic communities off Money Point in the Southern Branch of the Elizabeth River based upon quantitative sampling in summer 2016. The designated Money Point study area was part of a sediment contaminant remediation effort. The primary objectives were to: (1) characterize the biological health of the benthos of Money Point comparing pre-remediation condition (2010) to post-remediation condition in 2013 and again in 2016, and (2) assess the effectiveness of the sediment contamination remediation efforts with respect to the ecological condition of the Money Point benthos.

Prior to sediment contaminant …

Let's Dance! Designing And Assessing Dance-Integrated Lessons In The Fifth Grade Language Arts Class, Emily Lorraine Hoch

Master's Theses

The purpose of this study was to design movement and dance-integrated lessons that would complement a poetry unit in a fifth grade language arts class at a public charter school. This quantitative and qualitative study sought to discover how the use of creative movement and dance could improve students’ ability to communicate through writing, and revise their work, as well as assess how this approach to teaching would effect their ability to think critically. These integrated lessons aligned with Colorado State Core Standards and 21st Century skills, as dance integration promotes the use of creativity, critical thinking, communication and collaboration …

Dance For Special Needs Students: Building Confidence And Motor Skills, Jennifer Monique Dabalsa

Master's Theses

Participating in a dance class is influential in the development of young people’s creative, imaginative, individual, and communicative skills. The use of dance within a classroom increases physical fitness, enriches motor skills, coordination, and enhances social skills. Dance also increases muscular endurance, builds balance, as well as encourages teamwork and group skills. Most, if not all individuals crave to be socially accepted on some level. Many individuals with special needs are limited in verbal communication, or they are completely non-verbal. Connecting to individuals with these types of limitations proves to be challenging in comparison with a typical abled bodied individual. …

Statistical Linear Mixed Models For Evaluation Of Training Program In Hand Surgery Chief Residents, Zoe Michelle Ross

Honors Theses

Resident clinics (RCs) are intended to catalyze the achievement of educational milestones through progressively autonomous patient care. However, few studies quantify their effect on competency-based surgical education, and no previous publications focus on hand surgery RCs. This study aims to use statistical theories and knowledge of descriptive statistics and inference statistics, such as confidence intervals, two sample t-tests, correlation and association tests, as well as statistical model building such as analysis of variance with random effects and mixed linear models. We hypothesize that the higher a resident’s training years, the higher the autonomy score (quality of surgery) will be. We …

An Analysis Of Prevalence Of Chytrid Fungus In An Amphibian Assemblage In Middle Tennessee, Cameron Brocco

Honors Theses

Chytridiomycosis is an infectious, fungal disease largely seen in amphibians, which is caused by the highly virulent, zoosporic, pathogenic, single-celled fungus Batrachochytrium dendrobatidis (Bd). It is known to cause epidermal hyperplasia, hyperkeratosis, skin ulcerations, and fatalities by asystolic cardiac arrest either from shifts in electrolytes or increased acidity in the blood plasma. Previous research has demonstrated that urban water bodies have a higher prevalence of chytrid fungus than rural water bodies. Researchers have also found that chytrid is more prevalent in open canopy habitats than closed canopy habitats. Furthermore, it is implicated in global population declines and local extinctions in …

Predicting The Author Of Twitter Posts With Markov Chain Analysis, Daniel Freeman

Honors Theses

Given a set of text with known authors, is it possible to take new text, not knowing who wrote it, and correctly identify the author? One way to do this is to analyze the text using Markov chains. This research project will first attempt to answer this question using books available in the public domain. Using what is learned from trying to identify authors of books, the primary goal of this project is to identify the best way to guess the author of a post on the social media network Twitter using Markov chains.

Gradus Ad Parnassum: A Reader's Edition And Commentary, Sara Miller Schulte

Masters Theses

The seminal eighteenth-century counterpoint treatise Gradus ad Parnassum by Johann Joseph Fux exists in Latin, German, French, Italian, Spanish, and a host of other languages in its entirely, but in English only the second book of two has been translated, and even that is available only in a collection of partial translations. While a complete English translation is well beyond the scope of this project, toward that end, this research makes a case for its completion and provides a modernized edition and commentary of the as-yet-untranslated first book.

A Novel Linear Diophantine Equation-Baesd Low Diameter Structured Peer-To-Peer Network, Shahriar Rahimi

Dissertations

This research focuses on introducing a novel concept to design a scalable, hierarchical interest-based overlay Peer-to-Peer (P2P) system. We have used Linear Diophantine Equation (LDE) as the mathematical base to realize the architecture. Note that all existing structured approaches use Distributed Hash Tables (DHT) and Secure Hash Algorithm (SHA) to realize their architectures. Use of LDE in designing P2P architecture is a completely new idea; it does not exist in the literature to the best of our knowledge. We have shown how the proposed LDE-based architecture outperforms some of the most well established existing architecture. We have proposed multiple effective …