Digital Commons Network^™

Modeling, Analysis, And Simulation Of Adsorption In Functionalized Memebranes, Anastasia Bridner Wilson

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The emergence of biopharmaceuticals, and particularly therapeutic proteins, as a leading way to manage chronic diseases in humans has created a need for technologies that deliver purified products efficiently and quickly. Towards this end, there has been a signif-icant amount of research on development of porous membranes used in chromatographic bioseparations. In this work, we focus on high-capacity multimodal membranes developed by Husson and colleagues in the Department of Chemical and Biomolecular Engineering at Clemson University. Chromatographic performance of such membranes, particularly the adsorption ca-pabilities of the membranes, depends of a large number of variables making it unrealistic to scan …

Time Based Modeling Of Storage Facility Operations, Nadeepa Devapriya Wickramage

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This dissertation studies routing in storage facilities with stackable unit loads with time as the objective function. In the storage facilities, orders need to be stored as well as picked and material handling vehicles can carry more than one unit load at a time if the unit load containers are stackable on each other. In the first part of this research where the number of unit loads the vehicle can carry is limited to two and only one unit load can be stored at a location, a mathematical model was developed to find optimal paths for multi-command operations to route …

The Effects Of Mathematics Placement On Successful Completion Of An Engineering Degree And How One Student Beat The Odds, Jennifer Elizabeth Van Dyken

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This dissertation comprises a sequential explanatory mixed methods study seeking to understand persistence in engineering based on a student’s initial mathematics course and the experience of a student who began in the lowest level mathematics course and completed an engineering degree despite struggling in mathematics courses. The first phase of the quantitative piece examines one year retention rates for first year engineering students based on initial mathematics course. In the second quantitative phase a stepwise logistic regression model was conducted to determine what factors are related to engineering persistence. The third quantitative phase is a retrospective study to determine the …

Estimation And Control Of Traffic Relying On Vehicular Connectivity, Nianfeng Wan

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Vehicular traffic flow is essential, yet complicated to analyze. It describes the interplay among vehicles and with the infrastructure. A better understanding of traf-fic would benefit both individuals and the whole society in terms of improving safety, energy efficiency, and reducing environmental impacts. A large body of research ex-ists on estimation and control of vehicular traffic in which, however, vehicles were assumed not to be able to share information due to the limits of technology. With the development of wireless communication and various sensor devices, Connected Vehicles(CV) are emerging which are able to detect, access, and share information with each …

Topological Phenomena In Metals And Superconductors, Girish Sharma

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The eponymous Dirac equation originated in 1928 as a classic attempt to provide the com-plete theory of a relativistic quantum electron. Weyl, Majorana and Dirac fermions, which are relevant in particle physics have also recently also sprung up in condensed matter physics. It has been realized that some condensed matter systems can host novel fermionic quasiparticle excitations in direct analogy to Weyl, Majorana and Dirac fermions. More interestingly when the band struc-ture topology of some of these systems becomes non-trivial, they can be classified as topological condensed matter systems. In this thesis we will discuss non-trivial topological features of metals …

Trust-Based Control Of (Semi)Autonomous Mobile Robotic Systems, Hamed Saeidi

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Despite great achievements made in (semi)autonomous robotic systems, human participa-tion is still an essential part, especially for decision-making about the autonomy allocation of robots in complex and uncertain environments. However, human decisions may not be optimal due to limited cognitive capacities and subjective human factors. In human-robot interaction (HRI), trust is a major factor that determines humans use of autonomy. Over/under trust may lead to dispro-portionate autonomy allocation, resulting in decreased task performance and/or increased human workload. In this work, we develop automated decision-making aids utilizing computational trust models to help human operators achieve a more effective and unbiased allocation. …

Learning Energy Literacy Concepts From Energy-Efficient Homes, Frederick Eugene Paige

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The purpose of this study is to understand ways that occupants’ and visitors’ interaction with energy efficient home design affects Energy Literacy. Using a case study approach including interviews, surveys, and observations, I examined the potential for affordable energy efficient homes in the Greenville South Carolina area to "teach" concepts from an Energy Literacy framework developed by dozens of educational partners and federal agencies that comprise the U.S. Global Change Research Program Partners. I paid particular attention to concepts from the framework that are transferable to energy decisions beyond a home’s walls.

My research reveals ways that interaction with high …

Particle Transport Phenomena In Non-Newtonian Microfluidics, Xinyu Lu

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In the past two decades, microfluidic devices have become attractive platforms for many chemical and biomedical applications due to their enhanced efficiency and accuracy at a reduced cost. Many of the fluids encountered in these applications exhibit non-Newtonian behaviors. However, the majority of current particle transport studies have been limited in Newtonian fluids only. Very little work has been done on particle transport in non-Newtonian fluids. This dissertation presents experimental and numerical studies of particle transport phenomena in both electric field- and pressure-driven flows in non-Newtonian fluids through microchannels. In the first part, electrokinetic transport phenomena are investigated in viscoelastic …

An Examination Of International Teachers' Pedagogical Adaption To U.S. Secondary Mathematics Classes, Dennis A. Kombe

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Since the early 1990s, there has been a considerable uptick in the recruitment of international teachers to the U.S. to teach subject areas that experience perennial teacher shortages, including mathematics, science, special education, and languages, in hard-to-staff, high needs urban or rural K-12 schools. However, research is only starting to emerge that considers the social and pedagogical transition processes of these teachers. This study examines how international secondary mathematics teachers negotiate dialectics, and tensions, between their perceptions of effective mathematics teaching practices in their home contexts as compared to expectations in U.S. public schools, and relatedly, how international teachers’, and …

Examination Of Infographics-Based Reusable Learning Objects (Rlo) And Traditional Didactic Lectures (Tdl) To Improve Consumer Knowledge And Perceptions About The Safe Use Of Plastic Food Containers In A Microwave Oven, Najla Ahmed Khateeb

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This study was a quasi-experimental trials that compared relative effectiveness of Infographics Based Reusable Learning Objects Educational Intervention (RLO and Traditional Didactic Lectures (TDL). A total of 282 Clemson university students were randomized into four groups – Control, RLD, TDL and RLO+TDL and changes in their pre-test and post-test scores were compared before and after each interventions. Specific outcomes tracked included the number of correctly recognized symbols identifying a type plastic, the number of correctly answered question about the safety of using plastic food containers in a microwave and the satisfaction with the instruction. The analysis suggests that RLO intervention …

Artificial Neural Networks, Non Linear Auto Regression Networks (Narx) And Causal Loop Diagram Approaches For Modelling Bridge Infrastructure Conditions, Srimaruthi Jonnalagadda

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The quality of highway bridge infrastructure in United States is of major concern. One in every four bridges in the US is deficient. This research applied Artificial Intelligence, Systems Dynamics and linear modeling techniques to investigate the causes and effects of bridge deterioration and to forecast bridge infrastructure condition and improvement costs. The main contribution of the research is the development and demonstration of these methods within the context of highway bridges. These methods provide bridge designers and policy makers new tools for maintaining, improving, and delivering high quality bridge infrastructure. To start with, a comprehensive review of the current …

Algebraic Geometry Arising From Discrete Models Of Gene Regulatory Networks, Qijun He

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Discrete models of gene regulatory networks have gained popularity in computational systems biology over the last dozen years. However, not all discrete network models reflect the behaviors of real biological systems. In this work, we focus on two model selection methods and algebraic geometry arising from these model selection methods. The first model selection method involves biologically relevant functions. We begin by introducing k-canalizing functions, a generalization of nested canalizing functions. We extend results on nested canalizing functions and derived a unique extended monomial form of arbitrary Boolean functions. This gives us a stratification of the set of n-variable Boolean …

An Analysis Of Three Trio Student Support Services Projects At Public Two-Year Institutions In South Carolina, Caroline W. Canty

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In recent years, TRIO Programs have been targeted for budget cuts. The development of more data-based arguments is needed to defend these programs. Arguments against the continuation of TRIO programs stem from concerns about the program’s relevancy and success. Specifically, Student Support Services (SSS) operates at higher education institutions to support the college or university’s efforts with retention and graduation. The purpose of this study is to determine whether the services provided by TRIO SSS lead to successful outcomes for the participants served. A content analysis was conducted on artifacts from three distinct Student Support Services projects located in the …

The Adaptable Growth Of Seashells: Informing The Design Of The Built Environment Through Quantitative Biomimicry, Diana Ann Chen

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Our current design philosophy in the creation and planning of our country’s infrastructure exudes an attitude of nonchalance that is incongruous with the significant impact the built infrastructure has on the natural environment. We are living through an era of obsolescence, in which structures are demolished thoughtlessly as they outgrow their ability to meet human demands. Obsolescence can be viewed as a “hazard” in the sense that this phenomenon is leaving swaths of buildings in unusable and undesirable conditions, lessening the quality of host locales, and polluting the environment with demolitions and the need for more construction resources. Designing our …

The Initial Design And Validation Of The Teachers' Emotions, Appraisals, And Coping Habits When Facilitating Inquiry-Based Instruction (Teach-Fibi) Instrument For Science Education, Daniel Mason Alston

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Since the mid 1900’s, authors of science reform documents have advocated for teachers to engage in inquiry-based instruction. However, most science teachers, even highly qualified teachers, are not enacting teaching practices that align with what constitutes as proficient inquiry-based instruction. Currently, new science reform documents, in the form of The Framework for K-12 Science Education and the Next Generation Science Standards (NGSS), are asking teachers and students to engage in even more rigorous and challenging teaching and learning. Inquiry-based instruction is once again an advocated strategy for accomplishing the high expectations set forth in both documents. Many science teachers are …

Solution Techniques For Classes Of Biobjective And Parametric Programs, Nathan Adelgren

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Mathematical optimization, or mathematical programming, has been studied for several decades. Researchers are constantly searching for optimization techniques which allow one to de-termine the ideal course of action in extremely complex situations. This line of scientific inquiry motivates the primary focus of this dissertation — nontraditional optimization problems having either multiple objective functions or parametric input. Utilizing multiple objective functions al-lows one to account for the fact that the decision process in many real-life problems in engineering, business, and management is often driven by several conflicting criteria such as cost, performance, reliability, safety, and productivity. Additionally, incorporating parametric input allows …

Development Of An Automated Impedance Tomography System And Its Implementation In Cementitious Materials, Tao Ruan

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Electrical impedance tomography (EIT) based non-destructive evaluation showed great potentials in assessing the health condition of the new or existing civil infrastructures. Damages or anomalies that on the surface and embedded inside the structures exhibited as local conductivity changes and altered the path of electrical current flow. This investigation was focused on developing a new automated EIT system and employing EIT to identify the anomalies in cementitious materials structures.

This dissertation is structured as follows. First, common nondestructive evaluation (NDE) techniques including conductivity-based techniques were summarized as well as their advantages and disadvantages. Then the theories of EIT modality as …

Computational Studies Of Molecular Mechanisms Mediating Protein Adsorption On Material Surfaces, Tigran M. Abramyan

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Protein adsorption at material surfaces is a fundamental concept in many scientific applications ranging from the biocompatibility of implant materials in bioengineering to cleaning environmental material surfaces from toxic proteins in the area of biodefense. Understanding the molecular-level details of protein-surface interactions is crucial for controlling protein adsorption. While a range of experimental techniques has been developed to study protein adsorption, these techniques cannot produce the fundamental molecular-level information of protein adsorption. All-atom empirical force field molecular dynamics (MD) simulations hold great promise as a valuable tool for elucidating and predicting the mechanisms governing protein adsorption. However, current MD simulation …

Supervisory Control Optimization For A Series Hybrid Electric Vehicle With Consideration Of Battery Thermal Management And Aging, Xueyu Zhang

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This dissertation integrates battery thermal management and aging into the supervisory control optimization for a heavy-duty series hybrid electric vehicle (HEV). The framework for multi-objective optimization relies on novel implementation of the Dynamic Programing algorithm, and predictive models of critical phenomena. Electrochemistry based battery aging model is integrated into the framework to assesses the battery aging rate by considering instantaneous lithium ion (Li+) surface concentration rather than average concentration. This creates a large state-action space. Therefore, the computational effort required to solve a Deterministic or Stochastic Dynamic Programming becomes prohibitively intense, and a neuro-dynamic programming approach is proposed to remove …

Towards An Efficient Cloud Computing System: Data Management, Resource Allocation And Job Scheduling, Jinwei Liu

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Cloud computing is an emerging technology in distributed computing, and it has proved to be an effective infrastructure to provide services to users. Cloud is developing day by day and faces many challenges. One of challenges is to build cost-effective data management system that can ensure high data availability while maintaining consistency. Another challenge in cloud is efficient resource allocation which ensures high resource utilization and high SLO availability. Scheduling, referring to a set of policies to control the order of the work to be performed by a computer system, for high throughput is another challenge. In this dissertation, we …

Optimization Techniques For Modern Power Systems Planning, Operation And Control, Karthikeyan Balasubramaniam

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Recent developments in computing, communication and improvements in optimization techniques have piqued interest in improving the current operational practices and in addressing the challenges of future power grids. This dissertation leverages these new developments for improved quasi-static analysis of power systems for applications in power system planning, operation and control.

The premise of much of the work presented in this dissertation centers around development of better mathematical modeling for optimization problems which are then used to solve current and future challenges of power grid. To this end, the models developed in this research work contributes to the area of renewable …

Numerical Study For Non-Newtonian Fluid-Structure Interaction Problems, Shuhan Xu

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In this work, we consider non-Newtonian fluid structure problems, which have significant applications in biology and industry. Numerical approximation schemes are developed based on the Arbitrary Lagrangian-Eulerian (ALE) formulation of the flow equations. A spatial discretization is accomplished by the finite element method, and the time discretization is carried out by the implicit Euler method. We first consider a fluid-structure interaction problem that consists of a two-dimensional viscoelastic flow and a one-dimensional structure equation. We show how the system can be decoupled and how each subproblem can be solved using interface conditions. Numerical results of different algorithms are presented, showing …

Sustainable Enrollment Management: A Dynamic Network Analysis, Forrest Murray Stuart

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The primary purpose of this study was to investigate higher education enrollment management (EM) as a complex adaptive system (CAS) and to provide colleges and universities a foundational understanding of what a sustainable EM system looks like from a Dynamic Network Analysis (DNA) perspective. Additionally, I aimed to describe how formal network structures either promote or inhibit sustainable EM. To this end, the following research questions guided this study: 1. To what extent is the research site organized to enable effective and efficient information flow? 2. Which combinations of independent network measures (adaptive leadership, social capital, and clique structure) produce …

Clarity Of View: An Analytic Hierarchy Process (Ahp)-Based Multi-Factor Evaluation Framework For Driver Awareness Systems In Heavy Vehicles, Dee Kivett

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Several emerging technologies hold great promise to improve the situational awareness of the heavy vehicle driver. However, current industry-standard evaluation methods do not measure all the comprehensive factors contributing to the overall effectiveness of such systems. The average commercial vehicle driver in the USA is 54 years old with many drivers continuing past retirement age. Current methods for evaluating visibility systems only consider field of view and do not incorporate measures of the cognitive elements critical to drivers, especially the older demographic. As a result, industry is challenged to evaluate new technologies in a way that provides enough information to …

A New Look At Matrix Analytic Methods, Jason Joyner

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In the past several decades, matrix analytic methods have proven effective at studying two important sub-classes of block-structured Markov processes: G/M/1-type Markov processes and M/G/1-type Markov processes. These processes are often used to model many types of random phenomena due to their underlying primitives having phase-type distributions. When studying block-structured Markov processes and its sub-classes, two key quantities are the “rate matrix” R and a matrix of probabilities typically denoted G. In [30], Neuts shows that the stationary distribution of a Markov process of G/M/1-type, when it exists, possess a matrix-geometric relationship with R. Ramaswami’s formula [32] shows that the …

Characterization Of Tributyl Degradation Using Ftir-Atr Spectroscopy And Carbon Stable Isotope Ratio Mass Spectrometry, April Renae Gillens

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Tributyl phosphate (TBP) is used as an extractant in the Plutonium and Uranium Reduction Extraction (PUREX) process, as well as the Aqueous Chloride Process for Plutonium (Pu) recovery. These processes use nitric acid and hydrochloric acid, respectively. After nuclear reprocessing, TBP may be degraded in the Alkaline Hydrolysis Process using >12.5 M NaOH at 120-130 oC. TBP degrades to dibutyl phosphate (DBP), monobutyl phosphate (MBP), butanol, and phosphoric acid during hydrolysis. The goal of this dissertation is to use carbon stable isotopes to determine if there is a unique signature in TBP associated with nuclear reprocessing and solvent disposal. Acid …

On Becoming A Graduate Student Teacher Of Mathematics, Eliza Dargan Gallagher

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As a nation, we face a critical need to expand and enhance the STEM workforce and to improve the quantitative literacy of our populace. Doing so requires effective instruction in mathematics at all levels, from pre-kindergarten through post-graduate studies. However, while much work has been done to improve K-12 teacher preparation in mathematics, and to help new faculty members learn to balance research and teaching duties, we are only beginning to address the preparation of mathe-matics graduate students to teach. Moreover, those limited efforts have, until recently, been largely focused on imparting teaching strategies rather than on developing a teacher …

Nutrient Related Mechanisms Of Intervertebral Disc Degeneration, Sarah Elizabeth Cisewski

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The intervertebral disc (IVD) separates the vertebrae allowing flexibility, strength, as well as a wide range of mechanical motion in the spine. Millions of Americans are afflicted with IVD degeneration which can cause low back pain and limited functionality of the spine. Deviation from physiological nutrient levels due to abnormal mechanical loading and age is believed to be one of the main mechanisms for low back pain associated disc degeneration. Since the IVD is the largest avascular structure in the body, transport of nutrients (e.g., O2 and glucose) is primarily done through the passive transport mechanism of diffusion. Transport of …

Middle School Subject Area Teachers' Self-Efficacy With English Language Learners: A Mixed Methods Study, Tracy Dawn Butler

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The population of English language learners (ELLs) within the US has been steadily increasing over the past 20 years, thereby escalating the need for teachers to be knowledgeable in how to teach these students. However, research indicates that many teachers are not receiving adequate English as a Second Language (ESL) professional development. Lack of professional development in ESL strategies may adversely affect teachers’ self-efficacy because they are unfamiliar with methods to assist their ELL students in learning academic content. The purpose of this research study was to determine if particular subject areas taught by middle school teachers engender a higher …

Experimental And Numerical Modeling Of Wildfire Spread Via Fire Spotting, Ali Tohidi

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Wildfire spread via fire spotting phenomenon has three major stages, namely formation and break-off of firebrands from vegetative structures, lofting and transport of them through the ambient velocity field, and finally deposition of firebrands upon landing and ignition of spot fires. This dissertation develops novel models in different areas related to fire spotting phenomenon and integrates them to improve understanding of the firebrand flight through a multiphysics model. In this regard, a mechanical break-off model for the formation of cylindrical firebrands from coniferous trees is proposed; And by geometric scaling analysis, it is shown that the firebrand surface area scales …