Digital Commons Network^™

Functionalized Cellulose Nanofiber Membranes For Heavy Metals Removal From Impaired Waters, Nithinart Chitpong

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This dissertation describes the development and performance of high-productivity nanofiber membranes for removal of heavy metal ions from impaired waters. Heavy metal pollutants such as cadmium and nickel are present in wastewaters discharged from facilities in various industries. Water purification systems such as ion-exchange processes have been used widely to remove and recover specific metal ion impurities from wastewaters for ensuring that the maximum discharge limits of heavy metals are not exceeded. However, the productivity of an ion exchange resin process is limited by the high pressure drop across the resin bed, which may increase over time due to media …

Complex Network Analysis And The Applications In Vehicle Delay-Tolerant Networks, Bo Wu

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Vehicle Delay Tolerant Networks (VDTNs) is a particular kind of Delay Tolerant Networks (DTNs), where vehicles equipped with transmission capabilities are interconnected to form Vehicle NETworks (VNETs). Some applications and services on the top of VDTNs have raised a lot of attention, especially by providing information about weather conditions, road safety, traffic jams, speed limit, and even video streamings without the need of infrastructures. However, due to features such as high vehicle mobility, dynamic scenarios, sparsity of vehicles, short contact durations, disruption and intermittent connectivity and strict requirements for latency, many VDTNs do not present satisfactory performance, because no path …

Effects Of Mismatched Math Self-Efficacy And Performance On Behaviors And Attitudes Of Engineering Students With Poor Math Preparation, Gustavo Moran

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This research is a sequential explanatory mixed methods study seeking to understand the influences of mathematics self-efficacy (math SE) on the behavior and attitudes of engineering students with poor math preparation behavior and attitudes in their first college math courses.

The quantitative phase of this research assessed the math SE of engineering students placed in non-college-level math courses at Clemson University. A total of 408 students completed a survey to classify their math SE level; based on the results of the quantitative data analysis, 11 engineering students were selected from different semesters between the Spring 2014 and Spring 2016 to …

A Critical Analysis Of Factors That Contribute To Maasai Land Appropriation: The Case Of Maasai Land Appropriation In Kajiado And Narok Counties In Kenya, Ben R. Koissaba

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The aim of this case study was to analyze events, practices, laws, and decrees that have contributed to Maasai land appropriation and acquisition from the perspective of the Maasai in order to make policy recommendations. This case study was both intrinsic (how the Maasai understood the situation of land appropriation and acquisition) and instrumental (what can others learn from the situation of the Maasai).

This study used a form of qualitative research known as a case study. This particular study uses both intrinsic and instrumental case study designs (Denzin and Lincoln, 2006, Stake, 1995). The goal of the intrinsic component …

Investigating Materials That Promote New Organic Methodology And Remediation Of Volatile Organic Compounds, Mckenzie Louise Campbell

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The need for environmentally safe reagents for the promotion of organic transformations is critical in order to reduce hazardous waste and byproducts associated with industrial-scale chemical processes. We have developed two practical methods that obviate the need for harsh oxidative and toxic brominating reagents in electrophilic halogenation reactions.

In our hands, a catalytic loading of the inexpensive, commercially available V2O5 (~$0.25/g) promotes the bromolactonization of a series of substituted alkenoic acids in isolated yields up to 97% by means of the in situ generation of bromenium (Br+) from bromide (Br−) at room temperature. This process obviates the need for molecular …

Vanadium Diselenide: On The Verge Of Charge Density Wave, Menghan Zhou

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Charge density wave (CDW) is a many-body state of matter in which both lattice and electron density are modulated by a new periodicity. CDW features discrete translational symmetry breaking, and mostly occurs in low-dimensional materials. Although CDW behaviors have been found in many materials, the underlying mechanism and the driving forces of CDW transition are still unclear. In particular, the origin of CDW in two-dimensional materials, especially in layered transition metal dicalchogenides (TMDCs), may be distinct from that in one-dimensional materials.

In this dissertation, the CDW transition in VSe2, a layered TMDC material, is explored. Density functional theory (DFT) calculations …

Connected Vehicles At Signalized Intersections: Traffic Signal Timing Estimation And Optimization, S. Alireza Fayazi

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Summary: While traffic signals ensure safety of conflicting movements at intersections, they also cause much delay, wasted fuel, and tailpipe emissions. Frequent stops and goes induced by a series of traffic lights often frustrates passengers. However, the connectivity provided by connected vehicles applications can improve this situation. A uni-directional traffic signal to vehicle communication can be used to guide the connected vehicles to arrive at green which increases their energy efficiency; and in the first part of the dissertation, we propose a traffic signal phase and timing estimator as a complementary solution in situations where timing information is not available …

Opportunities For Innovation: Game-Based Learning In An Engineering Senior Design Course, Erica B. Walker

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Game-based learning is a novel approach for teaching a studio design course, especially in engineering. As a field, engineering is innovative by nature but has a strong emphasis on thinking in a logical, analytical, organized, and structured way. This way of thinking serves graduates well, but professional engineers also need to be able to think creatively, problem solve, and work well with a team (ABET, 2014; Felder, 1996; Herrmann, 1995; Lumsdaine & Lumsdaine, 1995; Shuman, Besterfield-Sacre, & McGourty, 2005; Walesh, 2012).

This study compared two sections of a Bioengineering Senior Design course. The control section was taught primarily with seventy-five …

A Study Of The Static Bicycle Reposition Problem With A Single Vehicle, Ling Zu

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The Bicycle Sharing System (BSS), a public service system operated by the government or a private company, provides the convenient use of a bicycle as a temporary method of transportation. More specifically, this system allows people to rent a bike from one location, use it for a short time period and then return it to either to the same or a different location for an inexpensive fee. With the development of IT technology in the 1990s, it became possible to balance the bicycle inventory among the various destinations. In fact, a critical aspect to maintaining a satisfactory BSS is effectively …

Formulation Of An Interactive Ruled-Based Design Envelope For Ensuring Aftermarket Vehicle Dynamics Compliance, Xianjie Zhou

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The objective of this research is to develop an integrated system engineering methodology for the customization design to maximize vehicle performance upgrade freedom while ensuring vehicle dynamics compliance. A post-delivery modification framework, which is led by an aftermarket umbrella organization and involve various stakeholders has been established. The umbrella organization will be in charge of developing the design envelope and distribute to various aftermarket kit suppliers to generate specific products according to their brand essence. A generic mathematical representation of a (proprietary) ESC system has been developed for virtual certification purposes. This approach is a cost-effective alternative to physical on-road …

Simulation Of Reverse Osmosis And Osmotically Driven Membrane Processes, Peng Xie

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To address the increasingly severe global water shortage and pollution problem, reverse osmosis (RO) has been widely used because of its ability to produce high quality water. Meanwhile, related technologies have been developed, called osmotically driven membrane processes (ODMPs). These include forward osmosis (FO), which has potential for wastewater purification and desalination, and pressure retarded osmosis (PRO), which has the capacity to produce energy. The main problems associated with RO and ODMPs are concentration polarization and membrane fouling which deteriorate the quality and quantity of the permeate flux and increase the operating cost of the system. The task of this …

Physics-Based Models For Engine System Studies: Quasi-D Dual-Fuel Combustion And Real-Time Intake Charge Flow Estimation, Shuonan Xu

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Ever tightening emissions and fuel economy regulations provide a strong impetus for research on high-efficiency low-emission engine concepts. In addition, CO2 emission regulation and energy security considerations motivate investigations focused on alternative fuels. In the current heavy-duty fleet, diesel engines dominate the market due to their unmatched thermal efficiency. Nevertheless, they suffer from NOx and soot emissions and require complex aftertreatment systems to meet stringent regulations. Due to recent advancements of the Natural Gas (NG) extraction technology, its supply has become increasingly abundant. Conversion of Heavy Duty engines to NG operation provides a most effective way of increasing utilization of …

Spatial Analysis Of The Nutritional Risk Of Older Adults Participating In The Older Americans Act Program In South Carolina, 2013, Maciel Ugalde

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Malnutrition is a prevalent, serious, and often unrecognized health threat for older adults in the United States. The prevalence estimates of malnutrition in the elderly are highly variable as methods for detection are not standardized. It is dependent on the use of the different available tools, the population being studied, and the different settings (living at home, institutionalized, or hospitalized) The purpose of this study was to determine the spatial variation of the nutritional risk of Area Agencies on Aging (AAA) service recipients in South Carolina (SC) using factors that influence the nutritional status of older adults included in the …

Social Entrepreneurialism As Economic Development Policy, Peter Staples

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The overall theme of this dissertation is social entrepreneurship and economic development policy. Empirical studies show strong evidence of the important role entrepreneurship plays in economic development. Recently, social entrepreneurship has emerged as a distinct field of scholarly study with the potential to increase economic development activities. It has the added benefits of increasing social and human capital and of reducing market failure and government failure by assisting underserved and marginalized populations in improving their standards of living. In spite of this potential, entrepreneurship in general has been neglected as part of a comprehensive economic development policy. Social entrepreneurship in …

Kernel Smoothing And Tolerance Intervals For Hierarchical Data, Christopher Wilson

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Multistage sampling is a common sampling technique in many studies. A challenge presented by multistage sampling schemes is that an additional random term should be introduced to the linear model. Observations are identically distributed but not independent, thus many traditional kernel smoothing techniques, which assume that the data is independent and identically distributed, may not produce reasonable estimates for the marginal density. Breunig (2001) proposed a method to account for the intra-class correlation leading to a complex bandwidth involving high order derivatives for bivariate kernel density estimate. We consider an alternative approach where the data are grouped into multiple random …

Instructional Coaches And The Development Of Relational Trust, Kristin Adams Schulze

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The position of instructional coach has become common in elementary schools, arising from calls for increased student achievement that originate from education policy and changing curriculum standards. Research in regards to the effectiveness of instructional coaches positively impacting classroom teaching is abundant. A key factor in the coach's ability to positively impact classroom instruction is the coach's interpersonal skills and ability to establish relational trust with classroom teachers. This trust is necessary to make changes in teachers' practice, yet little is known about how coaches establish this trust with teachers. Therefore, this study will extend the literature by filling in …

Evaluating Indirect Calorimetry Methodology, Postural Energy Expenditure, And The Effects Of Diet And Exercise Recommendations, Collin Jeffrey Popp

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Scientific research provides the evidence necessary to build an effective framework for health recommendations. In a population of young, healthy adults the recommended duration of an indirect calorimetry measurement period when measuring resting energy expenditure was a minimum of 10 minutes, with the first 5-minutes being discarded. A steady state period was achieved during the second 5-minute segment of a 30-minute period. Furthermore, in a population of young women, short-term standing energy expenditure was statically greater than lying and sitting energy expenditure. However, recommendations to stand instead of sit may be negligible as the magnitude of the effect of short-term …

Characterization And Modeling Of Bond-Loss Behavior In Pretensioned Concrete I-Girders, Behnam Naji

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Bond-loss failures have been widely observed in load tests of precast-pretensioned concrete I-girders. This type of failure is associated with shear cracking near the support that interrupts anchorage of the strands, leading to loss of bond and slipping of the strands relative to the concrete. It has been experimentally demonstrated that this failure type can occur at load levels that are lower than the nominal shear and flexural capacities. Because bond loss can be the controlling factor for structural capacity, it is critical that strand anchorage be considered when detailing and calculating the capacity of I-girder end regions. This dissertation …

Efficient Analytics For Large Implicit Correlation Networks, Raghuveer Mohan

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Large “correlation”-type networks have applications in machine learning, data mining and analysis of large biological networks. These networks contain short length-k (on the order of thousands) feature vectors for every node in the network that describe the characteristic or behavior of that node. Edges between nodes are expressed as correlations, partial correlations or coherence between the corresponding feature vectors. If the number of nodes n is too large (on the order of millions), then the dense correlation network with size n×n is computationally infeasible even to explicitly store in memory, let alone to use for computation of standard network analytics …

Mitigating Risks Of Oil Sands Process Affected Water Using Hybrid Constructed Wetland Treatment Systems, Andrew David Mcqueen

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Mining leases in the Athabasca Oil Sands (AOS) region produce extensive volumes of oil sands process-affected water (OSPW) containing constituents that limit beneficial uses, including discharge into receiving aquatic systems. The aim of this research is to provide a scalable approach using hybrid constructed wetland treatment systems for the mitigation of problematic constituents in OSPW. In the first experiment in this dissertation, OSPW was characterized to identify constituents of concern (COCs) using chemical, physical, and toxicological analyses. Following identification of COCs, bench-scale manipulations (termed process-based manipulations [PBMs]) were used to remove or alter “classes” of COCs in an effort to …

The Intentionality Of Coaching Responses: Connecting Stances To Practices, Leigh Martin

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Limited research exists that highlights instructional coaching practices associated with teacher learning, practice, and student learning (McGatha, Davis, & Stokes, 2015; Gibbons & Cobb, 2011). This study investigates coaching as a high-leverage strategy for mathematics teacher learning as a way to contribute to this research base. My study examines one coach's practices with two different teachers in order to respond to questions in the field about the decision-making processes of coaches. More specifically, this study examines how one coach determined which practices to use and the ways in which one coach adapted her practices with teachers. This dissertation seeks to …

Affordance-Based Design Product Evolution Using Customer Feedback, Ivan Mata

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Designers can benefit from involving the user in the product development process. Understanding how users perceive products can help designers make decisions that better accommodate user needs. Though several methods have been created that involve the user at different stages of the design process, there is still no clear connection between user perceptions and product improvements. Affordance Based Design (ABD) provides the theoretical background needed to explore such connections. ABD is a systematic de-sign method that uses the concept of affordances to describe the interactions between users and products. The integration of ABD and genetic algorithms (GAs) is proposed as …

Effect From Substrate Binding And Selected Mutations For Allosteric Communication In Atm1 Type Abc Exporter, Yinling Liu

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This thesis employed molecular dynamics (MD) simulations to investigate the effects of substrate binding and site-direct mutation of proteins. Chapter 2 performed MD simulations to examine the substrate effects on the behavior of Atm1 type ABC exporter. We found that thiol-containing glutathione (GSH) bound Atm1 type ABC exporter undergoes the largest conformational changes characterizing the nucleotide binding domain (NBD) coming closer together. The intracellular loops ICL1 and ICL2 between NBDs and transmembrane domains (TMDs) associated with the biggest fluctuation in the first principle component from PCA analysis in GSH bound system. Also, unlocking and slide along each other of two …

Tunable Copper Microstructures In Blanket Films And Trenches Using Pulsed Electrodeposition, James Marro

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Copper interconnects in microelectronics have long been plagued with thermo-mechanical reliability issues. Control over the copper deposition process and resulting microstructure can dictate its material properties and reduce stresses as well as defects that form in the copper. In this thesis, pulse electrodeposition processing parameters were evaluated for their impact on the copper microstructure (grain size, texture, and twin density and stress state) through electron backscattering diffraction and wafer curvature measurements. Varying levels of constraint were also investigated for their effect on the copper microstructure to better understand the microstructures of more complex three-dimensional interconnects. Highly texture blanket copper films …

Studies In Organic Synthesis: Copper Mediated Allylic Substitutions, Synthesis Of Spiro 3(2H)-Furanones, Intermolecular Halofunctionalization Of Alkenes And Synthesis Of Difluorovinyl Ethers, Alfredo Picado-Valenzuela

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This dissertation encompasses 4 independent projects in the field of Methodology Development in Organic Synthesis. Chapter 1 summarizes our efforts in the regio- and stereocontrol of copper mediated allylic substitutions with rearrangement of the double bond (SN2') in (Z)-α-halo-β,γ-unsaturated esters, (Z)-α-phosphate-β,γ-unsaturated esters, (Z)-α-mesylate-β,γ-unsaturated esters, (Z)-α-pentafluorobenzoate-β,γ-unsaturated esters, (E)-α-chloro-β,γ-unsaturated esters and allylic cyanophosphates. Different organocopper compounds bearing alkyl or aryl substituents were prepared from organolithium and Grignard reagents, and then added to these unsaturated substrates. When lithium cuprates were employed in combination with (Z)-α-nucleofuge-substituted-β,γ-enoates, exclusive formation of the SN2' products (e.g., γ-substituted-α,β-unsaturated esters) were obtained in good yields and with complete stereoselectivity …

Characterization And Modeling Of Deformation, Springback, And Failure In Advanced High Strength Steels (Ahsss), Jun Hu

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New generations of advanced high strength steels (AHSSs), expected with tension strength exceeding 1000 MPa, sufficient cold-stamping ductility, and low-alloyed microstructure, are being highly sought for automotive lightweighting applications without compromising on neither performance nor cost standards. From the standpoint of metallurgy, the most straightforward solution is to realize complex microstructures in the new AHSSs with significant fractions of the strongest ferrous phase, martensite, in combination with the most ductile phase, austenite. Nevertheless, the preliminary-developed new AHSSs exhibit unique and complex deformation, failure, and springback characteristics compared with the conventional steel grades, which thereby bring significant challenges to the current …

Me Of The Lowercase Variety: Reflections On The American Dream, Power, Privilege, And Self, Jared M. Halter

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This critical qualitative, autoethnographic research project explored how i came to understand the American dream through stories shared with me during semi-structured interviews, scholarly literature, and my own lived experience. i utilized critical reflexivity to examine the ways in which race, gender, and class appear in a person's understanding of their life and the American dream. Critical whiteness theory, critical race theory and critical race feminism, and structuralist constructivism guided my understanding of the American dream and how it influences the ways in which individuals and i understand our lives. Through what i learned, i discuss how the American dream …

Investigation Into The Ecological And Toxicological Constraints On A Population Of Lesser Flamingos (Phoeniconaias Minor) At Kamfers Dam In Kimberley, South Africa, Lindsay Hill

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This study investigates the threats to a breeding population of lesser flamingos (Phoeniconaias minor) at Kamfers Dam in Kimberley, South Africa. The main threats include water quality/quantity, algal food source abundance and exposure to contaminants accumulating in the dam. Water quality testing and analysis of historical water quality reports were used to analyze the effects of the physical and chemical parameters on the algal assemblage at Kamfers Dam and determine if changes in the water quality could predict changes in the algal assemblage. Arthrospira fusiformis, the flamingos preferred food, was positively correlated with conductivity, total dissolved salts …

Understanding The Transcriptional Landscape Of Chinese Hamster Ovary (Cho) Cell Lines Using Next-Generation Sequencing Technology, Rna-Seq, Under Industrially Relevant Conditions, Yogender Kumar Gowtham

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Recombinant therapeutic proteins are widely used to treat life-threatening diseases including cancer. Chinese hamster ovary (CHO) cells have been used for over 25 years in the biopharmaceutical industry to produce recombinant therapeutics, where CHO cells produce almost one in three of the manufactured recombinant therapeutics. CHO cell lines are the preferred host for protein expression due to their ability to produce human-compatible protein glycosylation, mediate protein folding, ease of culturing in large-scale bioreactors and protein expression stability. However, several limitations exist in CHO cell bioprocessing, including low protein yields, resulting in high market prices of the biopharmaceuticals. Understanding of CHO …

On The Modal Effective Nonlinearity Of A Class Of Tapered-Cantilever Beams, Clodoaldo Jose Da Silva

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The objective of this dissertation is to investigate the influence of i) higher-order nonlinearities, and ii) assumed mode discretization on the approximate modal effective nonlinearity associated with the flexural response of thin metallic cantilever beams of a constant thickness and a linearly-varying width. To this end, in the first part of this dissertation, a nonlinear model of an Euler-Bernoulli metallic cantilever beam with an arbitrarily variable cross-section is derived. Unlike the common literature wherein the Lagrangian is truncated using a fourth-order Taylor series; here the series is truncated at the eighth order to study the influence of higher-order nonlinearities on …