Digital Commons Network^™

A Case Study Of Makerere University In Uganda Through The Lens Of U.S. Land-Grant Higher Education, Christina L. Hand

Graduate Theses, Dissertations, and Problem Reports (ETD)

This case study examines Makerere University through the lens of U.S. land-grant ideal and normative domains in order to provide a deeper understanding of global higher education. A case study uses multiple types of data to create a holistic perspective. As well as interviewing Makerere stakeholders representing diverse sectors, numerous documents and different types of media were analyzed enabling a triangulation of data. Six major themes emerged focusing on Makerere’s aspiration to be a research-led institution, the impact of neoliberalism, challenges in undergraduate education, the importance of reputation and saga, the ever-present role of the Ugandan government, and the continuing …

Optimal Deployment Of Air Vehicle As Communication Relay For Multiple Ground Vehicles, Juan David Pabon Arias

Graduate Theses, Dissertations, and Problem Reports (ETD)

Heterogeneous teams of both air and ground mobile vehicles can combine the advantages of mobility, sensing capability, and operation time when performing complex tasks. However, when ground vehicles operate in cluttered environments with randomized obstacles, they may experience line of sight (LoS) obstructions and loss of communication due to those obstacles. To mitigate this issue, an airborne relay can be positioned in the vicinity of the ground vehicles to aid communication by establishing two-hop communication links between the vehicles.

This thesis develops an analytical framework to calculate the probability of spanning a two-hop communication between a pair of ground vehicles …

A Longitudinal Study Of Factors That Affect User Interactions With Social Media And Email Spam, Wojciech M. Mazurek

Graduate Theses, Dissertations, and Problem Reports (ETD)

Given the rapid growth of social media and the increasing prevalence of spam, it is crucial to understand users’ interactions with unsolicited content to develop effective countermeasures against spam. This thesis focuses on exploring the factors that influence users’ decisions to interact with spam on social media and email. It builds upon prior work, which serves as a foundation for further research and conducting a longitudinal analysis. Our results are based on the analysis of 221 responses collected through an online survey. The survey not only gathered demographic information such as age, gender, and race but also collected data on …

Investigations Into Indole Formation: Base-Mediated Formation Of N-Hydroxy- And N-Alkoxyindoles, Ancillary Ligand Development For Watanabe-Cenini-Söderberg Cyclization, And Total Synthesis Of Racemosin B, Blaine Thomas Mcclay

Graduate Theses, Dissertations, and Problem Reports (ETD)

A novel, base-mediated cyclization was developed to form N-hydroxy- and N-alkoxyindoles from 2-(2-nitrophenyl)butenoates. Potassium tert-butoxide or sodium tert-pentoxide, with or without the in-situ addition of an electrophile, formed a multitude of N-hydroxy- and N-alkoxyindoles. The formation of these butanoate precursors was improved via a Barluenga coupling reaction. Novel 4,5,6,7-tetramethoxy-1,10-phenanthroline was utilized as an ancillary ligand within the Watanabe-Cenini-Söderberg reductive cyclization reaction conditions. These new reaction conditions produced high yields for sterically hindered 2-nitrostyrenes and the first synthesis of dilemmaone A using this reductive cyclization. Racemosin B was synthesized in a three-step process utilizing a …

Hydraulic Fracturing Treatment Optimization Using Machine Learning, Abdullah Johar

Graduate Theses, Dissertations, and Problem Reports (ETD)

Friction reducers are chemicals used in hydraulic fracturing to reduce friction between fracturing fluid and the wellbore walls, helping to overcome tubular drag at high flow rates. High viscosity friction reducers are increasingly used due to operational and economic benefits, but their optimal concentration for each stage of fracturing is not well studied. As a result, oil and gas companies often use more friction reducers than necessary to ensure designed injection rates are achieved and to avoid screening out, resulting in excess use of FR and economic losses. The primary goal of this Thesis is to fully comprehend and quantify …

Evaluating Electrification Of Fossil Fuel-Fired Boilers For Decarbonization Using Discrete Event Simulation, Nahian Ismail Chowdhury

Graduate Theses, Dissertations, and Problem Reports (ETD)

Decarbonizing fossil fuel usage is crucial in mitigating the impacts of climate change. CO2, which comprises the major portion of greenhouse gas, is emitted from burning fossil fuels. One of the significant sources of fossil fuel user is industrial process heating, and most of the heating in industrial processes is achieved through boilers. Electrification is a promising solution for decarbonizing these boilers, as it enables renewable energy sources to generate electricity, which can then be used to power the electric boilers. The electrification of boilers can reduce greenhouse gas emissions, improve air quality, and increase energy efficiency. However, it requires …

Multimodal Neuron Classification Based On Morphology And Electrophysiology, Aqib Ahmad

Graduate Theses, Dissertations, and Problem Reports (ETD)

Categorizing neurons into different types to understand neural circuits and ultimately brain function is a major challenge in neuroscience. While electrical properties are critical in defining a neuron, its morphology is equally important. Advancements in single-cell analysis methods have allowed neuroscientists to simultaneously capture multiple data modalities from a neuron. We propose a method to classify neurons using both morphological structure and electrophysiology. Current approaches are based on a limited analysis of morphological features. We propose to use a new graph neural network to learn representations that more comprehensively account for the complexity of the shape of neuronal structures. In …

A Study Of Accidental Daughter Crystals In Fluid Inclusions In Bedded Halite From The Permian Opeche Shale And Cedar Hills Sandstone Of The Midcontinental United States, Ryan James Prchlik

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ancient acid-saline lakes of the midcontinental United States deposited bedded halite during Permian time. These deposits are not typically preserved at the surface, but drill cores of the Opeche Shale of North Dakota and Cedar Hills Sandstone of Kansas contain preserved beds of halite. Halite from these ancient lakes have primary fluid inclusions that contain Permian lake water. Also included are accidental daughter crystals that were trapped inside the fluid inclusions at time of halite precipitation. Both the fluid and daughter crystals inside bedded halite can tell us about the geochemistry of original lake waters of Pangea.

Petrography and laser …

Sequence Checking And Deduplication For Existing Fingerprint Databases, Tahsin Islam Sakif

Graduate Theses, Dissertations, and Problem Reports (ETD)

Biometric technology is a rapidly evolving field with applications that range from access to devices to border crossing and entry/exit processes. Large-scale applications to collect biometric data, such as border crossings result in multimodal biometric databases containing thousands of identities. However, due to human operator error, these databases often contain many instances of image labeling and classification; this is due to the lack of training and throughput pressure that comes with human error. Multiple entries from the same individual may be assigned to a different identity. Rolled fingerprints may be labeled as flat images, a face image entered into a …

Community And Key Player Detection For Disrupting Illicit Drug Supply Networks In Social Media Platforms – Especially On Instagram, Akassi Rachel Niamke Aman

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis focuses on the pressing issue of illicit drug trafficking and its impact on public health and safety at a global level. With the advent of digital technologies and social media platforms, combating drug trafficking has become increasingly challenging for law enforcement and researchers alike. Among these platforms, Instagram, a popular photo and video-sharing social networking platform, has emerged as a prominent hub for drug trafficking activities.

In this study, we delve into the effectiveness of community and key player detection algorithms in identifying and disrupting illicit drug supply networks on Instagram. To conduct our research, we collected real …

Linkages Between Atmospheric Circulation, Weather, Climate, Land Cover And Social Dynamics Of The Tibetan Plateau, Shobha Kumari Yadav

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Tibetan Plateau (TP) is an important landmass that plays a significant role in both regional and global climates. In recent decades, the TP has undergone significant changes due to climate and human activities. Since the 1980s anthropogenic activities, such as the stocking of livestock, land cover change, permafrost degradation, urbanization, highway construction, deforestation and desertification, and unsustainable land management practices, have greatly increased over the TP. As a result, grasslands have undergone rapid degradation and have altered the land surface which in turn has altered the exchange of heat and moisture properties between land and the atmosphere. But gaps …

Effects Of Light/Dark Cycle Shifts On Delay Discounting, Katya A. Nolder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Shift-work conditions are a necessity for the constant provision of certain medical, industrial, and commercial services in modern society. Shift work is associated with the increased risk of many negative health outcomes, including type 2 diabetes, heart disease, reproductive issues, and cancer. Shift workers experience multiple levels of circadian-rhythm disruption, which may increase maladaptive decision making, and this may mediate the relation between shift work and negative health outcomes. Circadian-rhythm disruptions can be systematically investigated in the basic laboratory, and one type of procedure involves changing the light/dark cycle in the animal vivarium. The current study investigated effects of light/dark …

Development Of A Quasi-Dimension Gci Combustion Model Aided By Cfd, Jinsu Kim

Graduate Theses, Dissertations, and Problem Reports (ETD)

Advanced combustion strategies have been proposed to improve fuel efficiency while minimizing exhaust emissions. Gasoline compression ignition (GCI) combustion featuring partially premixed compression ignition (PPCI) and diffusion combustion has been recognized as an attractive, viable combustion strategy for its potential and advantages over conventional diesel and gasoline engines. The optimization of the GCI engine system requires the development of a quasi-dimensional GCI combustion model capable of simulating GCI combustion while requesting less computational burden than CFD simulation, which is very critical in engine system simulation. This study developed a quasi-dimension, phenomenological combustion model for PPCI and diffusion combustion to facilitate …

Stability Properties Of A System Of Receptors In The Presence Of Attractive Domains, Basim Mohammed Al-Maliki

Graduate Theses, Dissertations, and Problem Reports (ETD)

I use mathematical modeling to understand aspects of molecular processes in living cells. Specifically, we look at the first few steps in cell signaling. Signal initiation requires that receptors located on the cell membrane bind together to form dimers. Microscopic imaging of receptors on the cell membrane revealed that receptors tend to accumulate in small areas (clusters). Studies also show that the membrane has a complex landscape consisting of domains and barriers of various origin.

Here we study the way receptor dimerization is influenced by domains on the cell membrane. Our underlying hypothesis is that the physical and chemical properties …

Development Of Machine Learning Based Approach To Predict Fuel Consumption And Maintenance Cost Of Heavy-Duty Vehicles Using Diesel And Alternative Fuels, Sasanka Katreddi

Graduate Theses, Dissertations, and Problem Reports (ETD)

One of the major contributors of human-made greenhouse gases (GHG) namely carbon dioxide (CO2), methane (CH4), and nitrous oxide (NOX) in the transportation sector and heavy-duty vehicles (HDV) contributing to about 27% of the overall fraction. In addition to the rapid increase in global temperature, airborne pollutants from diesel vehicles also present a risk to human health. Even a small improvement that could potentially drive energy savings to the century-old mature diesel technology could yield a significant impact on minimizing greenhouse gas emissions. With the increasing focus on reducing emissions and operating costs, there is a need for efficient and …

Energy Digital Twins In Smart Manufacturing Systems, Anna Billey

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this thesis, an Energy Digital Twin for smart manufacturing systems was developed and evaluated. In particular, the study focused on bidirectional parameter communication between the physical and the virtual part with the aim of optimizing the energy used in the manufacturing process. Rising costs and the environmental impacts related to energy consumption have grown in importance worldwide. There are elevated concerns in sectors like manufacturing, leading to an urgent quest to reduce energy consumption. A recent advancement in Industry 4.0 technology, the Digital Twin, represents a promising smart technology and tool that researchers are investigating to help reduce energy …

Lithium-Ion Battery Safety Analysis With Physical Sub-Models, Samuel Abimbola Ogunfuye

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ever-increasing explosions occurring globally at a rapid rate and in diverse situations have re-established the fact that novel, faster, and more accurate approaches must be developed to analyze and possibly curb these explosions and avert their future occurrences. Experimental endeavors and computational fluid dynamics (CFD) simulations as compared to engineering models generally require enormous time, and resources, as well as a high-level of expertise and technicalities. This might, however, delay prompt analysis and the ability to draw conclusions, thereby causing setbacks in recommending safety measures for different situations and conditions. Therefore, robust models which are accurate and fast to give …

Interpretation Of The Tandem Mass Spectrum Of The Novel Psychoactive Substance 5f-App-Pinaca, Px-2, Christopher S. Poulos

Graduate Theses, Dissertations, and Problem Reports (ETD)

Designer drugs and novel psychoactive substances (NPSs) are continuously entering the black market and causing serious health problems among users. NPSs present an especially difficult challenge to forensic chemists and toxicologists because they are not well characterized and often involve families of structurally related analogs. In crime laboratories, mass spectrometry is commonly used as a part of an analytical scheme to characterize and identify unknown analytes. Towards this end, tandem mass spectra of questioned analytes are often compared to reference spectra of standards that are either collected contemporaneously with the analyte or collected previously and stored in a database. However, …

Longitudinal Sport Science Implementation In American Collegiate Men’S Basketball, Jason Stone

Graduate Theses, Dissertations, and Problem Reports (ETD)

The expanding opportunities to implement sport science frameworks in elite-level basketball environments coincide with the sport’s increasing global prominence. Concomitant to these opportunities is the continual growth of the sport technology market (e.g., wearables, force plates) and computational power (e.g., data management tools, coding capabilities), which yields solutions and challenges for both athletes and practitioners. Due to the rapid influx of new sport technologies in high performance environments, particularly American Collegiate Men’s Basketball, more formal and ecologically valid research on how to effectively utilize data derived from them, particularly over long periods of time (i.e., multiple seasons) is needed. To …

Energy Conversion In Plasmas Out Of Local Thermodynamic Equilibrium: A Kinetic Theory Perspective, Mahmud Hasan Barbhuiya

Graduate Theses, Dissertations, and Problem Reports (ETD)

The study of energy conversion in collisionless plasmas that are not in local thermodynamic equilibrium (LTE) is at the leading edge of plasma physics research. Plasma constituents in such systems can exhibit highly structured phase space densities that deviate significantly from that of a Maxwellian. A standard approach has emerged in recent years for investigating energy conversion between bulk flow and thermal energy in collisionless plasmas using the non-LTE generalization of the first law of thermodynamics. The primary focus is placed on pressure-strain interaction (PS) term, with a particular emphasis on its non-LTE piece called Pi − D. Recent studies …

Visual Sensing For Comprehensive Granular Traffic Data Collection In Support Of Intelligent Transportation Applications, Linjun Lu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Comprehensive granular traffic data collection has been identified as one of the most essential tasks in the development of intelligent transportation systems (ITS). With the recent advances in electro-optical sensors and computational capacities, machine vision is regarded as cost-efficient for traffic data collection. However, the existing vision-based methods are only applicable for collecting limited types of traffic data, and a unified method allowing for comprehensive traffic data collection is still missing in the existing literature. Moreover, there are still challenges that exist for the use of the existing vision-based methods in real settings, including low accuracy and compromised applicability due …

Enhancing The Forensic Comparison Process Of Common Trace Materials Through The Development Of Practical And Systematic Methods, Meghan Nicole Prusinowski

Graduate Theses, Dissertations, and Problem Reports (ETD)

An ongoing advancement in forensic trace evidence has driven the development of new and objective methods for comparing various materials. While many standard guides have been published for use in trace laboratories, different areas require a more comprehensive understanding of error rates and an urgent need for harmonizing methods of examination and interpretation. Two critical areas are the forensic examination of physical fits and the comparison of spectral data, which depend highly on the examiner’s judgment.

The long-term goal of this study is to advance and modernize the comparative process of physical fit examinations and spectral interpretation. This goal is …

Mapping Infiltration In An Urbanizing Mixed-Land-Use Watershed With Multi-Temporal Satellite Imagery, Sarah J. Higgins

Graduate Theses, Dissertations, and Problem Reports (ETD)

Digital soil mapping (DSM) is a field of soil science that aims to improve traditional soil maps by producing higher resolution predictive maps of soil properties using spatial environmental data. DSM has historically relied primarily on static environmental covariates—such as slope gradient, slope aspect, and other topographic variables derived from digital terrain models—for predicting static soil properties, like soil texture. Advancements in satellite imagery and statistical modeling improve the accuracy of digital soil maps by incorporating multi-temporal data that can capture landscape-scale change over relatively short periods of time. Adding these dynamic environmental covariates may be especially useful for spatial …

Analytical Heat Transfer Modeling Of The Microwave Heating Process: A Focus On Carbon Black, Craig Offutt

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electronic waste (e-waste) has become a significant environmental issue due to the rapid advancement of technology, increasing demand for electronic devices, and shorter lifespan of electronics. One critical step in processing the e-waste involves ball milling as a means of preparing the recycling e-waste for the recovery of critical materials. Ball milling is a technique that involves the mechanical crushing and grinding of electronic waste to reduce its size and improve its reactivity during recovery. Our focused recovery technique is based on a microwave recovery technique of these critical materials from e-waste. The size and distribution of the e-waste with …

Enabling Technologies For Chemical Synthesis: I. Selective Microwave Heating; Ii. Synthesis And Regioselective Cyclotrimerizations Of Tethered 1,6-Diynes, Amir Tavakoli

Graduate Theses, Dissertations, and Problem Reports (ETD)

Reaction discoveries, method developments, and technology advancements lie at the heart of synthetic organic chemistry. These innovations are essential for creating and manipulating complex molecules, which are the building blocks of many important chemical compounds, including pharmaceuticals, materials, and agrochemicals. Here, we first describe new methods to prepare neopentylene-tethered (NPT) 1,6-diynes which are valuable substrates for reaction discovery and target-oriented synthesis, especially in benzannulation strategies toward illudalane natural products. NPT 1,6-diynes have been employed as coupling partners in cyclotrimerization reactions for the synthesis of highly substituted benzene rings which present a persistent challenge in chemical synthesis and are underrepresented scaffolds …

Analysis Of The Root Causes Of Fatal Injuries In The United States Surface Mines Between 2008 And 2021., Maria Fernanda Quintero

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mining has long been recognized as a hazardous industry worldwide. An annual average rate of 10.3 fatal injuries per 100,000 workers was recorded in the United States between 2008 and 2021 (MSHA, 2022). This rate can be compared with the average of the industries with the highest average rates of fatal injuries—agriculture, forestry, fishing, and hunting; transportation and warehousing; and construction—which had average rates of 23.5, 13.1, and 9.9 fatal injuries per 100,000 workers, respectively, during the same period in the Unites States (U.S. Bureau of Labor Statistics, 2023).

The scope of this research is related to the fatal injuries …

Enantioselective Dearomatization Facilitated By Non-Covalent Interactions Of N-Heterocyclic Carbene Catalysts And Pyridinium Salts, Jack A. Patterson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Dihydropyridines are a practical organic scaffold commonly used for their pharmaceutical properties. Nucleophilic dearomatization of pyridines has proven to be a useful method in obtaining dihydropyridines. By using N-heterocyclic carbene (NHC) organocatalysts, dihydropyridines can be synthesized with high regioselectivity of the 1,4 regioisomer over the 1,2- regioisomer but often with low enantioselectivity. By incorporating non-covalent interaction contact points, we hypothesize that enantioselectivity can be enhanced. By synthesizing numerous NHCs, each proposed to exhibit a different type of non-covalent interaction (i.e., hydrogen bonding or ion pairing), an understanding of the secondary interactions within this reaction system can be studied and …

Identification Of Rockmass Deformation And Lithological Changes In Underground Mines By Using Slam-Based Lidar Technology, Francisco Eduardo Gil Hurtado

Graduate Theses, Dissertations, and Problem Reports (ETD)

In mining, hazards causing rib and roof fall accidents generally develop with time. The development of a hazard depends on factors like geology, excavation geometry, overburden stress, and mining-induced stresses. Hazard mapping in an underground mine is essential for roof and rib stability assessment. However, often it is neither practical nor economical to inspect and map vast areas of mine workings with limited personnel. New technologies, recently, have been adopted in the mining industry that can solve this problem. Advances in LiDAR technology and simultaneous localization and mapping (SLAM) algorithms have led to the development of portable and mobile laser …

Survival Of Listeria Monocytogenes On Organic Honeycrisp And Fuji Apples During Storage At 5, 12 And 22.5◦C, Connor S. Freed

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study aimed to evaluate and model the survival of Listeria monocytogenes on organic HoneyCrisp (HC) and Fuji (FJ) apples during storage at various temperatures. Fresh organic HC and FJ apples (without wax coating) obtained from a local wholesale market were inoculated with a 2-strain mix of L. monocytogenes followed by storage at 5.0 (22.9% RH), 12.0 (37.0% RH), and 22.5oC (50.4% RH) for 60, 35, 7 days, respectively, and periodically (day-0 to 60) analyzing microbial populations. Surviving L. monocytogenes were spread-plated on Modified-Oxford agar after 10 or 100-fold serial dilution. Data were analyzed using the mixed-model procedure of SAS …

Feature Extraction Of Footwear Impression Images For Quality Assessment, Alexandra Hill

Graduate Theses, Dissertations, and Problem Reports (ETD)

Forensic footwear impression analysis is a valuable tool in criminal investigations. Extracting useful features from images of footwear impressions is a critical step in this process. However, the quality of these images can vary widely, making feature extraction challenging. In order to give a quality assessment rating to a footwear impression image, the image should first be analyzed to extract features from the impression. In this paper, we present a method to extract features from a 2D grayscale footwear impression image. A Hierarchical Grid Model implementation has been adapted from use on a 3D dataset to assist in finding features, …