Digital Commons Network^™

Application Of Hot-Melt Extrusion And Fused Deposition Modeling On Screening Filaments And Developing Diverse Dosages, Pengchong Xu

Electronic Theses and Dissertations

Three-dimensional printing (3DP) provides a flexible and cost-beneficial solution to patient-centric medicine and its potential to challenge current pharmaceutical supply chains. Fusion deposition modeling (FDM) is one of the most commonly applied 3D printing techniques in pharmaceutical study. But the poor mechanical properties of printing filaments have limited mainly the application of FDM 3D printing in the pharmaceutical area. In this dissertation, the development of texture analysis methods to evaluate the printability of filaments was investigated first. The parameter “Stiffness” was successfully developed to measure and predict the printability of filaments in the direct-extrude FDM printer. Then, the combination of …

Diversity And Inclusion In Science Teaching Learning (Distl): Focusing On The Perspectives Of Undergraduate Students And Graduate Teaching Assistants In The Chemistry Classroom, Albert Aidoo

Electronic Theses and Dissertations

Students in Science, Technology, Engineering and Mathematics (STEM) come with a wide range of experiences and educational backgrounds. There is high attrition rate and low academic achievement among students in STEM areas, specifically in college chemistry courses that are prerequisites for many STEM majors. Hence it is important to look at diversity and inclusion specifically in first- and second-year college chemistry courses to address the challenge of student attrition in STEM. Diversity can be understood as the differences each student brings along the dimensions of prior knowledge, skills, race, ethnicity, sexual orientation, gender, socio-economic status, age, ability, religious or political …

Effects Of Conservation Management Practices On Soil Health And Crop Yields In Eastern South Dakota, Alex Mclain

Electronic Theses and Dissertations

Conservation management practice adoption on agricultural land has increased in recent years due to increasing public and private investment. The anticipated impact of increasing conservation management practice adoption are reduced greenhouse gas emissions and improved soil, water, and air quality. Understanding how these conservation management practices affect agricultural producers economically is vital to properly incentivize these practices. The existing literature on how conservation management practices affect soil health and crop yields is mixed and generally has been conducted on experimental research stations. These studies may not fully account for the on-farm effects of conservation management practices. The objectives of this …

Totally Multicolored Rado Numbers For The Equation X_1 + X_2 + X_3 + ... + X_(M−1) = X_M, Skylar Halverson

Electronic Theses and Dissertations

A set is called Totally Multicolored (TMC) if no elements in the set are colored the same. For all natural numbers t, m, let R(t, m) be the least natural number n such that for every t-coloring of the set {1, 2, 3, ..., R(t, m)} there exist a solution set {x_1, x_2, . . ., x_m} to L(m), x_1 + x_2 + x_3 + ... + x_(m−1) = x_m such that x_i does not equal x_j for all i that does not equal j, that avoids being Totally Multicolored. This paper shows a function to find R(t,m) for any …

Using Long Short-Term Memory Networks To Make And Train Neural Network Based Pseudo Random Number Generator, Aditya Harshvardhan

Electronic Theses and Dissertations

Neural Networks have been used in many decision-making models and been employed in computer vision, and natural language processing. Several works have also used Neural Networks for developing Pseudo-Random Number Generators [2, 4, 5, 7, 8]. However, despite great performance in the National Institute of Standards and Technology (NIST) statistical test suite for randomness, they fail to discuss how the complexity of a neural network affects such statistical results. This work introduces: 1) a series of new Long Short- Term Memory Network (LSTM) based and Fully Connected Neural Network (FCNN – baseline [2] + variations) Pseudo Random Number Generators (PRNG) …

The Efficacy Of The South Dakota State University Summer Jacks Leap Program, Tessa M. Sundermann

Electronic Theses and Dissertations

Today, several studies detail the continuing struggle many students have with college mathematics courses at universities across the United States. The South Dakota State University Summer Jacks LeaP program is a summer bridge mathematics program aimed at improving incoming students’ mathematics success. This analysis used a mixed methods research design to examine the efficacy of the Summer Jacks LeaP program. First, we analyzed the LeaP students’ homework averages, exam 1 scores, final exam scores, and overall grade scores to determine if they were finding success in their fall semester mathematics courses. We also used hypothesis testing to compare LeaP participants …

Electron Spin Relaxation Of Nitroxide Spin Labels And Relaxation Processes, Thacien Ngendahimana

Electronic Theses and Dissertations

MTSL is the nitroxide spin label that is most commonly used in site-directed spin labeling. However, due to rotation of its gem-dimethyl groups that average anisotropic interactions, T_m becomes short above about 70 K and this makes DEER experiments difficult at these temperatures. Strategies for decreasing spin echo dephasing and electron spin lattice relaxation rates are important for design of nitroxide spin labels and molecular qubits.

In searching for labels with longer T_m, new nitroxide spin labels devoid of gemdimethyl groups or with more rigid structures were synthesized at the University of Nebraska and pulsed EPR measurements …

On Ramsey And Gallai-Ramsey Numbers Of Some Classes Of Graphs, Qinghong Zhao

Electronic Theses and Dissertations

In 1930, Frank Ramsey showed that one will find a monochromatic clique of a specified size in any edge coloring of a sufficiently large complete graph. This result is commonly known as Ramsey's theorem. The role of Ramsey number is to quantify some specific problems related to Ramsey's theorem. Given a graph H, the Ramsey number R_2(H) is the minimum integer p such that every 2-edge-coloring of the complete graph K_p contains a monochromatic copy of H. Ramsey numbers have been a hot topic in graph theory for decades due to their intrinsic beauty, wide applicability and overwhelming difficulty. Let …

Heuristic Algorithms For Transmission Switching To Reduce Load Shedding, Tanveer Hussain

Electronic Theses and Dissertations

No abstract provided.

Evaluating Avian Use Of Cover Crops In The Corn Belt, Megan Figura

Electronic Theses and Dissertations

The tallgrass prairie of North America has changed drastically since colonial settlement, with up to 99% of this region converted for agriculture and other land-uses. Concurrent with grassland conversion, grassland birds have experienced the most extreme, consistent, and widespread population declines of any avian guild. Agricultural lands in the U.S. Midwest were able to provide adequate habitat for several bird species until the 1950’s; however, altered and intensified management practices have degraded much of remaining suitable habitat and undermined ecosystem functions. Consequently, many grassland birds have been identified as Species of Greatest Conservation Need (SGCN) in many State Wildlife Action …

Pathogen Prevalence In Domestic Sheep In Western Nebraska: Implications For Bighorn Sheep Conservation And Coexistence On A Multi-Use Landscape, Kaytlin Bohr

Electronic Theses and Dissertations

Bighorn sheep (Ovis canadensis) and domestic sheep (Ovis aries) are members of the same genus and thus share multiple pathogens that can be spread between them. One specific respiratory pathogen of concern is Mycoplasma ovipneumoniae (M. ovipneumoniae), which has been linked to pneumonia epizootics in bighorn sheep that are often characterized by all age die offs upon initial exposure followed by years of low lamb recruitment. Domestic sheep have been identified as one carrier of M. ovipneumoniae with transmission between sheep species occurring when there is close contact on the landscape. To prevent this cross-species transmission, importance has been placed …

To Study The Factors Influencing The Sampling Variability On Microbiological Analysis Of Milk And Whey, Ratul Kalita

Electronic Theses and Dissertations

Sampling and analysis are integral parts of dairy processing in quality control, process monitoring and control, and meeting regulatory standards. Accurate sampling is vital to avoid erroneous analysis results and interpretation. The sampling process depends on the appropriateness of sample collection, transportation, storage, and analysis conditions. The bacterial heterogeneity and cluster formation, structural heterogeneity of food, sample unit and size, frequency, and sampling methods, are also crucial in sampling. We aimed to evaluate the influence of sample volume, sampling frequency, and sampling methods in experimental processing lines of whole milk, skim milk, and whey. To standardize the experimental protocols, a …

Development Of A Chromatographic Method To Authenticate Aspirin Brands, Megan Guetzloff

Electronic Theses and Dissertations

Counterfeit pharmaceuticals pose a threat to society that can include inaccurate amounts of the active pharmaceutical ingredient (API), no API, or containing off-target compounds. For example, there are many recent examples of counterfeit pharmaceuticals containing potentially lethal doses (> 2 mg) of fentanyl (i.e., a synthetic opioid). Current measures to combat illicit pharmaceuticals (e.g., unique packaging and product serialization) have merit, however with evolved technologies, counterfeiters can relatively easily simulate these measures and continue to distribute illicit pharmaceuticals. The only accurate way to definitively determine that a suspected counterfeit is, in fact, counterfeit is advanced chemical analysis. However, current methods …

Efficient Numerical Optimization For Parallel Dynamic Optimal Power Flow Simulation Using Network Geometry, Rylee Sundermann

Electronic Theses and Dissertations

In this work, we present a parallel method for accelerating the multi-period dynamic optimal power flow (DOPF). Our approach involves a distributed-memory parallelization of DOPF time-steps, use of a newly developed parallel primal-dual interior point method, and an iterative Krylov subspace linear solver with a block-Jacobi preconditioning scheme. The parallel primal-dual interior point method has been implemented and distributed in the open-source PETSc library and is currently available. We present the formulation of the DOPF problem, the developed primal dual interior point method solver, the parallel implementation, and results on various multi-core machines. We demonstrate the effectiveness our proposed block-Jacobi …

Improving Three-Dimensional Instructional Practices Via Professional Development, Alethea Henry

Electronic Theses and Dissertations

The purpose of this applied research study was to improve the use of three-dimensional pedagogy in science classes in chronically low-performing schools. The need to build teacher capacity became evident after the state adopted more rigorous science standards revealing deficits in teachers’ pedagogical content knowledge. This study utilized two elements, three-dimensional professional development and the science cadre, to build teacher capacity as well as foster collaboration and create buy-in throughout the district among science leaders. Data collected and analyzed from classroom observations, student surveys, and teacher interviews revealed improved usage of three-dimensional instruction and increased buy-in throughout the district to …

Phosphorus Use And Management Based On Fertilizer Placement, Rate Of Application, And Soil Biota In No-Till Situations, Brennan Alexander Bingham Lewis

Electronic Theses and Dissertations

Phosphorus (P) pollution has become a concern among multiple scientific organizations as it leads to eutrophication, an algal bloom that depletes lacustrine and marine ecosystems of native species. Multiple strategies can be implemented to reduce phosphorus loss from agriculture fields, which is often implicated as a cause of eutrophication. Soil phosphorus chemistry results in phosphate fertilizers absorbing to clay minerals over time. Soil phosphorus is lost from agricultural fields primarily through wind and water erosion. No-till practices prevent soil erosion, which reduces the phosphorus from loading into waterways. Fertilizer placement affects phosphorus loss. Surface application of phosphorus fertilizers increases the …

Factors Affecting The Farmers’ Adoption Decision And Usage Intensity Of Conservation Tillage In Eastern South Dakota, Sarmila Belbase

Electronic Theses and Dissertations

Many farmers are continuously looking for new ways to protect soil and increase yields and returns on investment. No-tillage and reduced-tillage farming may provide ways to achieve these goals. Such practices have been found as the alternative to overcoming the environmental challenge posed by conventional tillage practice and providing significant economic returns. However, a comprehensive study of the factors affecting the adoption and adoption intensity of these practices is lacking. This paper intends to fill this gap by utilizing a double hurdle model to analyze farmer survey data. The data used in this study were obtained from a survey of …

Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield

Electronic Theses and Dissertations

As eastern redcedar (ERC) (Juniperus virginiana L.) grassland encroachment progresses, all potential control methods should be explored in the interest of Great Plains grassland health and longevity. Targeted browsing with goats has been proven as an effective control method on some juniper species; however, little is known about its ability to control ERC. These studies intend to mend knowledge gaps of how targeted browsing with goats control ERC by causing tree death without chemicals or machinery. The first study is two 3x3 Latin squares comparing protein-supplemented diets. The second study is a randomized complete block design of five 0.224 ha …

Building Cultural Competence In Schools Through Teacher Capacity, Latonya R. Robinson

Electronic Theses and Dissertations

The purpose of this study was to understand the dynamics of how teaching culturally responsive strategies to teachers can help eliminate the opportunity gap between students of color and their White counterparts. The action research method involved first collecting quantitative data through several surveys and then explaining the quantitative results with in- depth qualitative data through interviews and professional learning communities. In the first phase of the study, the culturally responsive and teacher efficacy scale data was collected from the participants within the study and the district at large. While the district survey was not mandated, it was strongly encouraged. …

Perceptions Of English Learner Support Provided By K-12 Leaders To Educators In Mississippi, Ladonna Thomas

Electronic Theses and Dissertations

The demographic of public schools in America is continuously changing. According to the United States Department of Education (USDE), the English learner population increased in over 25 states from the 2009-2010 school year to the 2014-2015 school year (USDE, 2017). In 2014-15, there were more than 4,800,000 English learners enrolled in schools, accounting for 10% of the total student population (USDE, 2017). With this shifting demographic, educators must be prepared to meet the needs of EL students.

The purpose of this study is to examine educators and instructional leaders’ perceptions of EL instructional support and to highlight the need for …

On Symmetric And Computationally Efficient Gini Correlations In Several Bivariate Distributions Dissertation, Courtney Vanderford Michael

Electronic Theses and Dissertations

The standard Gini correlation plays an important role in measuring the dependence between random variables with heavy-tailed distributions. It is based on the covariance between one variable and the rank of the other. Hence, for each pair of random variables, there are two Gini correlations and they are not equal in general, which brings a substantial difficulty in interpretation. We study two symmetric and computationally efficient Gini correlations with the computational complexity of O(nlogn). The properties of the two symmetric Gini correlations are explored. The influence function approach is utilized to study the robustness and the asymptotic behavior of these …

Abaqus Implementation Of A Hyperelastic Damage Model For Glass-Reinforced Polymers Under Shock And Impact Loading, James Stuart Fraser

Electronic Theses and Dissertations

Accurate computational modeling of the ballistic response of heterogenous materials is crucial when designing lightweight armor and protective structures. Currently, due to the structural complexity inherent in composites, this behavior is poorly understood. In the present work, a novel computational model to describe the glass fiber-reinforced polymer (GRP) response to shock and impact loadings was implemented in the commercially available Abaqus© finite element software via a VUMAT subroutine. Before damage initiation, the model utilized an experimentally-determined tetragonally-symmetric stiffness matrix for the elastic representation of the GRP. Once damage was initiated, a hyperelastic continuum damage mechanics (CDM) based model described the …

The Impact Of The Good Behavior Game On Adolescent Student Behavior In Restrictive And Inclusive Learning Environments, Allison Nicole Oliver

Electronic Theses and Dissertations

This dissertation consists of three articles investigating the effects of the Good Behavior Game to increase academic engagement and decrease disruptive behaviors in students who have behavior disorders. Previous literature examined the effects of the Good Behavior Game on student populations in elementary and mainstream settings. Unfortunately, there is a lack of investigation with use of the Good Behavior Game in secondary settings with students with disabilities, especially behavioral disorders. Collectively, these three articles will determine the impact of the Good Behavior Game in secondary settings with students with behavior disorders in mainstream, inclusive and restrictive learning environments. This dissertation …

The Impact Of Ethnicity Within The Field Of Speech-Language Pathology, Maliah Wilkinson

Electronic Theses and Dissertations

The estimated racial/ethnic diversity within the field of speech-language pathology is considered to be less than 10% despite population trends predicting that over half of the United States’ population will be identified as a racial/ethnic minority by 2044 (Projections of the Size and Composition of the U.S. Population: 2014 to 2060, 2014). The limited diversity is likely to be coupled with inclusion and equity barriers in higher education (i.e., barriers related to financial and educational demographics, graduate school preparedness/support, etc.). In the field of speech language pathology, little is known about the impact of these challenges experienced by students from …

Closing The Opportunity Gap In Mathematics Education, Candies Nicole Winfun-Cook

Electronic Theses and Dissertations

Shifting our attention from the achievement gap (standardized test results) to the opportunity gap (unequal opportunities and experiences among students of differing socioeconomic and racial backgrounds) is necessary to shrink gaps in the American educational system. Although previous studies have focused on the achievement gap in terms of students’ success on standardized tests, there has been limited research on the missed opportunities experienced by Black, Indigenous, and people of color (BIPOC) in high school mathematics classrooms. This qualitative study revealed the lived experiences of BIPOC students as participating in college and career mathematics readiness activities in a single high school …

Understanding Classroom Engagement For Middle School Students, Jason W. Wood

Electronic Theses and Dissertations

The purpose of this study is to understand the dynamics of student engagement and motivation in middle school students. The action research method involves collecting quantitative data through a student survey first and then explaining the quantitative results with in-depth qualitative data through interviews and focus groups. In the first, quantitative phase of the study, the motivation and engagement scale data will be collected from middle school students in the fifth through eighth grade of Regents School of Oxford to test the motivation and engagement of these students to assess whether intrinsic motivations relate to classroom student engagement. The second …

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 …

Sentiment Without Sentiment Analysis: Using The Recommendation Outcome Of Steam Game Reviews As Sentiment Predictor, Anqi Zhang

Electronic Theses and Dissertations

This paper presents and explores a novel way to determine the sentiment of a Steam game review based on the predicted recommendation of the review, testing different regression models on a combination of Term Frequency-Inverse Document Frequency (TF-IDF) and Latent Dirichlet Allocation (LDA) features. A dataset of Steam game reviews extracted from the Programming games genre consisting of 21 games along with other significant features such as the number of helpful likes on the recommendation, number of hours played, and others. Based on the features, they are grouped into three datasets: 1) either having keyword features only, 2) keyword features …