Digital Commons Network^™

The Impact Of Blended Classroom Pedagogy On Student Gpa In A Community College Stem Course, Sarah Mattox Holt

Electronic Theses and Dissertations

America is facing a shortage of STEM workers and colleges must meet the demand by educating qualified graduates. However, attrition rates are high in STEM classes, particularly in minority groups. Blended learning has increased in popularity in higher education over recent years and has the potential to improve current teaching practices. Yet, limited research centers on the success of blended learning implemented in a community college STEM course. This quantitative research study (N=1264) was designed to evaluate student success in the blended learning environment versus traditional environment in an introductory community college biology course for science majors. The study indicated …

Dye And Redox Shuttle Interactions To Promote Fast Electron Transfer In Dye-Sensitized Solar Cells, Abeysinghe Mudiyanselage Dinesh Bandara Nugegoda

Electronic Theses and Dissertations

Harnessing the sun's power using dye-sensitized solar cells (DSCs) is a possible answer to address the energy challenge. Increasing the performance of DSC devices by increasing the rate of productive electron transfers is critically essential. In this regard, to increase the rate of electron transfers from the redox shuttle to the dye, a strategy of coordinating the redox shuttle through non-covalent interactions such as Lewis acid-Lewis base interactions, π-stacking interactions, and halogen bonding interactions to the dye are considered. DSC devices were fabricated using newly synthesized dyes and redox shuttle pairs to study each strategy. The performance of the devices …

Achieving Record Photocurrent: Strategies For Harvesting And Utilizing Low Energy Photons In Organic Dye-Sensitized Photovoltaics, Jonathon Watson

Electronic Theses and Dissertations

An urgent challenge limiting the improvement of dye-sensitized solar cell (DSC) technology is the availability of chromophores capable of harvesting the full spectrum of solar irradiation; this is especially evident at longer wavelengths. Therefore, the achievable power conversion efficiency (PCE) is effectively capped due to limited photocurrent generation. Molecular design strategies involving proaromaticity and cross-conjugation are employed in this work to facilitate access to low-energy near-infrared (NIR) photons. Utilizing the ubiquitous Donor–p-spacer–Acceptor (D–p–A) architecture, these concepts are studied by incorporating an indolizine donor (RR13 and RR14), and thieno[3,4-b]pyrazine (allowing additional substitution for cross-conjugation, JW1) and thieno[3,4-b]thiophene (AP25) p-spacers. The sensitizers …

Optimization Based Parameter And State Estimation Framework For Remote Microgrid Frequency Dynamics Modeling Using Probing Signals From Energy Storage Systems, Manisha Rauniyar

Electronic Theses and Dissertations

The primary aim of this thesis is to deliver an efficient design and selection of probing signal needed to estimate state and parameters representing the power system frequency dynamics with the proposed estimation technique in real-time with minimum computational time and cost. These test cases are designed for power system researchers that need to estimate and control analysis at the remote microgrid level. Case studies are presented that can be simulated at the transmission and distribution level in power grids, and in remote isolated microgrids where the independent system operator (ISO) has control. Increasing utilization of renewable energy sources and …

Making The Invisible Visible: Redefining Giftedness To Include Ell Students’ Community Cultural Wealth And Funds Of Knowledge, Molly I. Pargas

Electronic Theses and Dissertations

This study used improvement science methods to investigate a problem of practice surrounding the underrepresentation of ELL students in GT programming. This research addressed how teachers define giftedness using their underlying knowledge frameworks. The researcher conducted empathy interviews with parents of ELL students and a team of teachers to determine what the underlying issues are regarding the underrepresentation of ELL students in GT. The parent empathy interviews were coded using the combined conceptual framework of community cultural wealth (Yosso, 2005) and funds of knowledge (Moll et al, 1992). Through this process the types of capital and funds of knowledge were …

A Call For Critically Inclined Higher Education Data, Wendy A. Fish

Electronic Theses and Dissertations

The economic logic of neoliberalism has reached its zenith—now firmly entrenched in our political, social, and cultural transactions (Giroux, 2014; Harvey, 2005). As a result, we stand on the precipice of a new era—the data era—in which neoliberalism’s orientation towards accountability, micro-management, and hierarchical ordering mediates all social and political narratives. Data, it is said, is fast becoming “the new oil”—the most valuable global resource (Bhageshpur, 2019; Harari, 2018).

This is problematic. Although there are countless ways in which the application of data has improved the world, it has a long, dark history as a technology of oppression. Yet, data …

Investigaion Of The Gamma Hurdle Model For A Single Population Mean, Alissa Jacobs

Electronic Theses and Dissertations

A common issue in some statistical inference problems is dealing with a high frequency of zeroes in a sample of data. For many distributions such as the gamma, optimal inference procedures do not allow for zeroes to be present. In practice, however, it is natural to observe real data sets where nonnegative distributions would make sense to model but naturally zeroes will occur. One example of this is in the analysis of cost in insurance claim studies. One common approach to deal with the presence of zeroes is using a hurdle model. Most literary work on hurdle models will focus …

Revision Total Hip Femoral Stem Micromotion And Statistical Shape Modeling Of The Knee, William Fugit

Electronic Theses and Dissertations

The first purpose of this thesis was to compare the amount of micromotion seen in the femoral stem in a revision total hip arthroplasty between simple loading conditions and loading conditions derived from activities of daily living, through the use of experimental and computational methods. The amount of micromotion at the bone-implant interface was larger for activities of daily living, with ranges of 200μm more than the largest simple loading conditions. The second purpose of this thesis was to compare measurements of accuracy in a statistical shape model between individual bone and joint-level models, specifically for the knee. Using computational …

Formulation, Structure, And Applications Of Therapeutic, Amino Acid, And Water-Based Deep Eutectic Solvents, Md Sajjadur Rahman

Electronic Theses and Dissertations

In the design of greener chemicals, deep eutectic solvents (DESs) are considered as one of the most versatile alternative solvents with widespread applications. DESs have the advantages of being nonflammable with negligible vapor pressure compared to traditional solvents. They share many characteristics of ionic liquids, but DESs are cheaper to formulate, typically nontoxic, recyclable, biodegradable, and are suitable for use with biological systems. In my Ph.D. research, three types of emerging and unconventional types of DESs, namely therapeutic DES (THEDES), amino acid-based DES (AADES), and water-based DES (WDES), have been investigated. To formulate these DES easily available and cheaper chemicals, …

Soil Hydro-Physical Properties, Computed Tomography Measured Pore Parameters, And Soil Health Indicators As Influenced By Tillage And Crop Rotation Systems, Goutham Thotakuri

Electronic Theses and Dissertations

Long-term tillage and crop rotation systems are important agricultural management practices as these can have direct impact on the soil’s key properties. The objectives of this study were to (ⅰ) quantify the soil pore characteristics under long-term tillage and crop rotation using X-ray computed tomography (XCT) and to assess the relationships between XCT-measured pore parameters and soil hydro-physical properties; and (ⅱ) evaluate the impacts of long-term tillage and crop rotation on select soil health indicators. The objective (ⅰ) was carried out at Haskell Agricultural Laboratory (HAL), Concord, NE; and objective (ⅰi) was carried out at South Central Agricultural Laboratory (SCAL), …

Study On Performance Of Pruned Cnn-Based Classification Models, Mengling Deng

Electronic Theses and Dissertations

Convolutional Neural Network (CNN) is a neural network developed for processing image data. CNNs have been studied extensively and have been used in numerous computer vision tasks such as image classification and segmentation, object detection and recognition, etc. [1] Although, the CNNs-based approaches showed humanlevel performances in these tasks [2], they require heavy computation in both training and inference stages, and the models consist of millions of parameters. This hinders the development and deployment of CNN-based models for real world applications. Neural Network Pruning and Compression techniques have been proposed [3, 4] to reduce the computation complexity of trained CNNs …

It's Not Just No-Till: Crop Rotations Are Key To Improving Soil Quality And Grain Yields At Dakota Lakes Research Farm, Natalie Sturm

Electronic Theses and Dissertations

No-till is increasingly promoted as a vital agricultural practice to address the challenge of improving soil quality while maintaining the ability to produce food, feed, fuel, and fiber. However, questions remain regarding 1) how different crop rotations impact soil quality under no-till management specifically and 2) whether significant improvements in soil quality can be made without negatively impacted crop yields. In this study, we demonstrate that even under the same long-term no-till management, differences in grain yields and soil biological, chemical, and physical properties exist between crop rotations at Dakota Lakes Research Farm in central South Dakota. We propose that …

Combining Soil Health And Fertility Measurements To Improve The Accuracy Of Predicting Corn Grain Yield Responses To P And K Fertilization, Benjamin Groebner

Electronic Theses and Dissertations

Researchers have pointed to changes in climate and land management practices to justify the need to reevaluate the accuracy of current South Dakota (SD) corn (Zea mays L.) P and K fertilizer recommendations. Also, an increase in soil health understanding has created the potential for soil health measurements to be used to improve the accuracy of these recommendations. The objectives for this study were to 1) evaluate the current P and K critical values and 2) determine the effect of including soil health indicators on improving fertilizer recommendation accuracy. This project was conducted throughout central and eastern SD from 2019-2021 …

Disentangling The Complex Evolutionary History Of Invasive Russian Thistle: Phylogenetic Relationships, The Role Of Hybridization, And Public Engagement, Deva Raj Khanal

Electronic Theses and Dissertations

Invasive species are forces of environmental, economic, and social change with detrimental impacts on ecosystems, commerce, agriculture, and human health. However, we still have a poor understanding of the processes that could be driving invasive potential. Hybridization may contribute to the establishment and spread of invasive lineages, as it may enhance genetic variation and facilitate rapid adaptation. Focusing on Russian thistle (Salsola tragus s.l., family Amaranthaceae) and closely related species, my thesis aims to clarify phylogenetic relationships and investigate how hybridization has shaped the invasion dynamics of these lineages. Known as one of the fastest plant invasions in the United …

A Post-Pneumonia Epizootic Evaluation Of The Rapid City, South Dakota Bighorn Sheep Herd, Amanda N. Ensrud

Electronic Theses and Dissertations

Pneumonia is a major factor affecting populations of free-ranging bighorn sheep (Ovis canadensis) across western North America. Pneumonia can occur in large-scale epizootics, during which greater than half of the population typically dies. After these epizootics, surviving ewes continue to conceive and bear lambs. However, lamb recruitment may remain low due to periodic or annual pneumonia outbreaks causing high lamb mortality rates, sometimes greater than 90%. Our study focused on the Rapid City, South Dakota bighorn sheep (BHS) herd that has recorded pneumonia-induced population decline since 2009. The first objective was to improve lamb health and survival by identifying and …

Post-Fledging Habitat Selection And Movements Of Juvenile Mallards In The Prairie Pothole Region, Cynthia E. Anchor

Electronic Theses and Dissertations

The Prairie Pothole Region (PPR) of North America provides critical habitat for waterfowl across life stages, but anthropogenic changes to the landscape have negatively impacted habitat quality for waterfowl. The mallard (Anas platyrhynchos) is abundant and socioeconomically valuable in the PPR, as it is a preferred target species of waterfowl hunters. Extensive research has evaluated breeding ecology of mallards in the PPR, but the period between juvenile mallards fledging and migrating has rarely been studied. The post-fledging ecology of juvenile mallards is a vital consideration for comprehensive waterfowl management. Further, juvenile mallards are a significant portion of hunter harvest at …

Northern Great Plains Saline Sodic Soil Development, Classification, Remediation, And Management., Shaina Westhoff

Electronic Theses and Dissertations

Soil salinity and sodicity are issues of growing concern in the United States (U.S.) and globally. Knowledge gaps for glaciated, dryland salt-affected soils exist because much original salinity and sodicity research focused on irrigated systems. Land managers are being asked to produce food, feed, fiber, and fuel for an expanding global population. The number of land managers and crop advisors who are affected by these soils is increasing. Addressing salinity and sodicity knowledge gaps will be critical for their success. Salinity and sodicity have been impeding crop productivity since the advent of cultivation. Saline and sodic soils form via multiple …

The Immobilization Of Ticagrelor On Implant Materials And Corrosion And Biofouling Inhibition By Novel Layered Polymer Thin Films For Marine Application, Tell Lovelace

Electronic Theses and Dissertations

Percutaneous coronary interventions are a widely used cardiovascular surgery which is typically accompanied by the insertion of a vascular stent. After the procedure patients are put on dual anti-platelet therapy (DAPT) to prevent stent thrombosis, a common complication to this procedure in which platelets aggregate in the blood vessel on the inserted stent. Systemic deactivation of platelets in patients via oral DAPT results in patients becoming bleeding risks in future medical procedures, necessitating the development of a localized delivery system for anti-platelet medications from the surface of the stent. A novel anti-thrombogenic vascular stent coating has been prepared by covalent …

Forced Together, Growing Apart: An Exploration Of Heterosexual African American Males' Disengagement In Romantic Relationships With African American Females, Kenya Johns

Electronic Theses and Dissertations

The decline of intraracial dating has been more pronounced among African Americans in comparison to other racial groups. There is lack of available research tailored towards Black men’s dating experiences. The purpose of this study was to explore the lived experiences of heterosexual African American males related to their disengagement in romantic relationships with African American females.

A phenomenological study explored the lived experiences of 10 African American males and the dynamics that appear to contribute to the decline in intraracial dating in the African American community. Five themes emerged from the study: – self-regard, family matters, proximity, the new …

Seasonal Flammability Comparisons Of Native And Exotic Plants In The Post Oak Savannah, Blackland Prairie, And Pineywoods Ecoregions Of Texas, Michael Tiller

Electronic Theses and Dissertations

East Texas’ diverse landscape can present year-round wildfire seasons that can be influenced by seasonal and regional differences in climate and physiography. Greater insight into the fundamental thermal behavior of wildland fuels can aid in fire behavior prediction and development of fire-resistant plant lists. This study focused on estimating seasonal and regional flammability characteristics of five evergreen species: yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), greenbrier (Smilax spp.), eastern red cedar (Juniperus virginiana), and escarpment live oak (Quercus fusiformis); and two deciduous species: Chinese tallow (Triadica sebifera) and southern …

Stratigraphic Analysis Of The Capps Limestone In The North Norton Oil Field In Runnels County, Texas, William Thompson

Electronic Theses and Dissertations

The Desmoinesian (Middle Pennsylvanian) Capps Limestone Member of the Mineral Wells Formation is a carbonate reservoir located in North Central Texas. It consists of interbedded limestone, sandstone, and shale units. Much of the Capps Limestone exists in the subsurface of Brown, Coleman, Runnels, Coke, Nolan, and Taylor counties, however, the Capps Limestone outcrops on the surface in Brown, Eastland, and Palo Pinto counties.

The cored interval from Runnels County was deposited in a marginal marine environment during the Middle Pennsylvanian Period. Although the Capps Limestone was first described in the 1890s, there is still much to be discovered about its …

Drone Location And Scheduling Problems In Humanitarian Logistics., Zabih Ghelichi

Electronic Theses and Dissertations

Unmanned Aerial Vehicles (UAVs), commonly referred to as drones, are a promising technology for the last-mile delivery of medical and aid items in humanitarian logistics. In emergency scenarios, like disasters, where transportation networks are destroyed and people are stranded, drones can accelerate the delivery of urgently needed items, e.g., food and water, insulin shots and blood pressure pills, to those trapped in the disaster-affected areas. Drones can also provide logistics services in many non-emergency situations by delivering medical items, e.g., vaccine shots and lab specimens, to remote communities and hard-to-access locations. The contribution of using UAVs goes beyond merely having …

Digital Design And Thermomechanical Process Simulation For 3d Printing With Abs And Soyhull Fibers Reinforced Abs Composites., Saleh Khanjar

Electronic Theses and Dissertations

Recent demonstrations with fused filament fabrication (FFF) 3D printing have shown to produce prototypes as well as production components. Additionally, due to the FFF process platforms being low-cost and readily available there has been a high-demand to produce on-demand parts for various applications in automotive, in-space manufacturing and electronic industries. However, current limitations such as limited availability of advanced composites materials, and guidelines for design-for-manufacturing make the process prone to trial-and-error experiments both at the materials development, product design and manufacturing stage. In this work, new thermomechanical process simulations platform, Digimat-AM has been evaluated to address and demonstrate digital design …

Computational Modeling Of 3d-Printed Lactobacillus-Antibiotic Scaffolds For Bacterial Vaginosis., Veeresh P. Rai

Electronic Theses and Dissertations

The standard treatment for bacterial vaginosis (BV) is currently antibiotics, such as metronidazole, clindamycin, or tinidazole. These antibiotics are highly effective in getting rid of bacteria in the female reproductive tract (FRT); however, there are some bacteria that provide benefits to the FRT which also get expunged. While there are many strains of bacteria that play a beneficial role in the FRT, lactobacilli are among the most important. These bacteria are responsible for maintaining a healthy environment in the FRT via pH regulation by lactic acid metabolism. Antibiotics eliminate all bacteria from an environment, including lactobacilli, and as a result, …

Pyridine Nucleotide Redox Potential In Coronary Smooth Muscle Couples Myocardial Blood Flow To Cardiac Metabolism., Marc Matthew Dwenger

Electronic Theses and Dissertations

The maintenance of myocardial oxygen supply during stress is essential for sustaining cardiac health. Enhancement of coronary blood flow upon increases in myocardial oxygen demand (i.e., hyperemia) relies on regulation of voltage-gated K⁺ (Kv) channels by their intracellular β subunits (i.e., Kvβ proteins). Considering that, Kvβ proteins are aldo-keto reductases (AKRs) and regulate Kv channel gating, we tested the hypothesis that elevation of myocardial oxygen demand modifies intracellular NAD(H) in arterial myocytes. Furthermore, we tested whether the resultant change in the redox state of the pyridine nucleotide pool directly regulates coronary Kv1 channel activity. High-resolution imaging mass spectrometry and …

Decisive Neutrality, Restricted Decisive Neutrality, And Split Decisive Neutrality On Median Semilattices And Median Graphs., Ulf Högnäs

Electronic Theses and Dissertations

Consensus functions on finite median semilattices and finite median graphs are studied from an axiomatic point of view. We start with a new axiomatic characterization of majority rule on a large class of median semilattices we call sufficient. A key axiom in this result is the restricted decisive neutrality condition. This condition is a restricted version of the more well-known axiom of decisive neutrality given in [4]. Our theorem is an extension of the main result given in [7]. Another main result is a complete characterization of the class of consensus on a finite median semilattice that satisfies the axioms …

Study Of The Cell Membrane And The Synthesis Of Chimeric Human Bacterial Phospholipids, Opeyemi O. Tade

Electronic Theses and Dissertations

Phospholipid bilayers are the principal component of the cell membrane. Membranes ensure the maintenance of processes required for cells’ survival by regulating the inflow and outflow of nutrients and other molecules using membrane proteins. However, studying the cell membrane is challenging because of its complexity and small size. In-vitro membrane models made of phospholipids are important tools for studying membranes. In this work, we aim to study the fluidity of phospholipid bilayers of different lipids using general polarization (GP) of the fluorescent probe Laurdan as a measure. We will focus on the relative importance of head groups and fatty acids …

Hybrid Structural Health Monitoring Using Data-Driven Modal Analysis And Model-Based Bayesian Inference., Jice Zeng

Electronic Theses and Dissertations

Civil infrastructures that are valuable assets for the public and owners must be adequately and periodically maintained to guarantee safety, continuous service, and avoid economic losses. Vibration-based structural health monitoring (VBSHM) has been a significant tool to assess the structural performance of civil infrastructures over the last decades. Challenges in VBSHM exist in two aspects: operational modal analysis (OMA) and Finite element model updating (FEMU). The former aims to extract natural frequency, damping ratio, and mode shapes using vibrational data under normal operation; the latter focuses on minimizing the discrepancies between measurements and model prediction. The main impediments to real-world …

Distinguishing Mustela From Neogale (Mustelidae) Through Both A Qualitative And Quantitative Analysis Of Skull And Tooth Morphology, Ronald W. Peery

Electronic Theses and Dissertations

Weasels and mink (Mustela and Neogale) can be difficult to distinguish osteologically due to similarities in morphology, thus suggesting the need for an accurate tool in distinguishing among taxa. This study utilized a combination of character state and stepwise discriminant function (DFA) analyses to examine potential distinguishing features of skull and tooth morphology. Measurements and ratios were collected from all 18 extant musteline species, as well as the extinct Neovison macrodon, Mustela rexroadensis, Mustela meltoni, Mustela gazini, and Mustela jacksoni. Unidentified musteline specimens from the Gray Fossil Site were also included. Results of …

Estimating Treatment Effect On Medical Cost And Examining Medical Cost Trajectory Using Splines And Change Point Techniques., Indranil Ghosh

Electronic Theses and Dissertations

In the world of growing medical needs, other than the clinical outcomes, the cost of healthcare is one of the important aspects to evaluate. The cost of treatment could act as a decisive factor on which one to choose from two equally likely effective treatment options. In literature, the most used quantity for the cost of treatment is cumulative lifetime cost since the diagnosis of a disease. While it provides a bird' eye view of the treatment cost, it fails to capture the underlying pattern of the treatment cost trajectory. We developed a marginal structural functional model (MSFM) using an …