Digital Commons Network^™

Characterization Of Lower Rio Grande Valley Watershed, Abdulkabir O. Aduragba

Theses and Dissertations

The Lower Laguna Madre (LLM) is considered impaired because of the high concentration of bacteria and low level of dissolved oxygen (DO). LLM receives freshwater from the Lower Rio Grande Valley (LRGV) watershed. In other to understand the impairment, LRGV watershed is being studied by relying on water quality data of the contributing drainages and State resource geographic data to identify watershed boundary and pollutant sources.

The study on the North and Central LRGV watershed shows some correlation between the concentration of E. coli/Bacteria, Ammonia, Total Kjeldahl Nitrogen, Total Phosphorus, Nitrate and Nitrite, Chlorophyll-a and the sources of pollutant in …

Formation Control Of Multiple Quadrotors, Miguel Alejandro Garcia

Theses and Dissertations

This thesis studies formation control of multiple quadrotors under different conditions. Two controller design approaches are proposed. In the first approach, it is assumed that the dynamics of each quadrotor is unknown and there is disturbance. With the aid of distributed estimation and the universal approximation property of neural networks, distributed tracking controllers are proposed. Simulation shows the effectiveness of the proposed controllers. In the second approach, it is assumed that the inertia parameters are unknown. With the aid of distributed estimation, online data estimation, and optimal control theory, distributed sub-optimal tracking controllers are proposed. Simulation results show the effectiveness …

Graphene-Conductive Ink Coated Laser Engraved Kapton Electrochemical Biosensor For The Detection Of Dopamine And Immune Sensing, Dipannita Ghosh

Theses and Dissertations

Novel and flexible disposable laser-engraved Kapton (LEK) electrodes modified with graphene conductive inks have been developed for dopamine and Interleukin-6 (IL-6) detection. The LEK sensors exhibit high reproducibility (RSD=0.76%, N=5) and stability (RSD=4.39%, N=15)after multiple bendings, and thus make the sensors ideal for wearable and stretchable bioelectronics applications. We have developed graphene conductive ink- PEDOT:PSS (G-PEDOT:PSS) and polyaniline (G-PANI) based electrode coatings for working electrode modification to improve the sensitivity (41.41 times higher for screen printed electrode with G-PEDPT:PSS ink modification),and limit of detection (LOD) . We have further compared the performance of the fabricated electrodes with commercially available screen-printed …

Developing Executable Digital Models With Model-Based Systems Engineering – An Unmanned Aerial Vehicle Surveillance Scenario Example, Viviana Guadalupe Lopez

Theses and Dissertations

There is an increase in complexity in modern systems that causes inconsistencies in the iterative exchange loops of the system design process and in turn, demands greater quality of system organization and optimization techniques. A recent transition from document-centric systems engineering to Model-Based Systems Engineering (MBSE) is being documented in literature from various industries to address these issues. This study aims to investigate how MBSE can be used as a starting point in developing digital twins (DT). Specifically, the adoption of MBSE for realizing DT has been investigated, resulting in various literature reviews that indicate the most prevalent methodologies and …

Wave Excited Mass-Spring-Damper System For A Self-Recharging Autonomous Underwater Vehicle, Mahmodul Hasan Maheen

Theses and Dissertations

Autonomous underwater vehicles' (AUVs) endurance is constrained by the lifetime of their batteries and the distance that tether wires can traverse. Solving the endurance problem of AUV using the enormous potential of ocean wave energy is the motivation behind this thesis. The objective of this research is to model a mass-spring-damper system to emulate the permanent magnet linear generator (PMLG) of a self-recharging AUV and identify its energy absorption capability through numerical simulation and experimental testing. The research activities started with modeling and fabricating a 1:5 scale model. The scaling was done by comparing the most common AUV size of …

The Effects Of Carbon Coating On The Electrochemical Performance Of Metal-Oxide Short Fiber Anodes For Lithium-Ion Batteries, David A. Sanchez

Theses and Dissertations

This thesis focuses on the process of oxidizing centrifugally spun precursor fibers and the subsequent process of carbon coating via chemical vapor deposition (CVD) for use as anode material in lithium-ion batteries (LIBs). Metal oxides have been studied as a potential replacement for graphite as they have been shown to have high theoretical capacities, good electronic conductivity, and can be synthesized using low-cost, scalable methods. However, metal oxides with high theoretical capacities also have low cycle life. To avoid this, metal oxides have been integrated with carbon to expand their life cycle. The work in this thesis shows the synthesis …

Electrodialysis Process For The Simultaneous Treatment Of Reject Brine And Capture Of Carbon Dioxide, Jawad Mustafa

Dissertations

Desalination plants are highly efficient in producing desalinated water for potable applications. However, the process also generates reject brine, which is highly concentrated saline water. In order to produce 1 liter of potable water using desalination, approximately 1.5 liters of reject brine is generated. The disposal of reject brine presents a significant challenge for the desalination industry. Typically, this waste product is discharged into the sea, causing environmental damage, and polluting marine life. Moreover, certain countries heavily rely on desalination to meet their potable water needs, which results in the emission of greenhouse gases. As desalination plants consume a significant …

Cfis’ Safety Behaviors At Flight Training Schools: Understanding The Effects Of Personality Traits, Self-Efficacy, Risk Perception, And Safety Climate, Vivek Sharma

Theses and Dissertations

The purpose of the current study was to investigate the relationship between personality traits, affective domain variables, safety climate, and safety behaviors of certified flight instructors (CFIs). Personality traits consisted of the five dimensions of the Big Five personality model, including Extraversion, Neuroticism, Agreeableness, Openness, and Conscientiousness. Affective domain variables included self-efficacy and risk perception. The study used an explanatory correlational design to determine the relationship between the targeted factors and safety behaviors. The dependent variable was CFIs’ safety behaviors. The sample consisted of 134 CFIs who completed all of the study’s protocols. Participants were obtained from a professional flight …

Improving The Learning Efficiency Of Adaptive Optimal Control In Information-Limited Environments, Omar Ghassan Qasem

Theses and Dissertations

This work investigates the adaptive optimal control problems for continuous-time linear and nonlinear systems. A novel adaptive dynamic programming method, namely hybrid iteration (HI) is presented. Different from the existing adaptive dynamic programming methods, i.e., policy iteration (PI) and value iteration (VI), the HI does not require an initial admissible control policy compared to the PI. On the other hand, the HI converges to the optimal control policy in much less learning iterations and CPU time compared to the VI due to the ensured quadratic rate of convergence of the HI method, which is much faster than the sub-linear convergence …

Xeno-Free Biomimetic Ecm Model For Investigation Of Matrix Properties On Astrocyte Cell Response, Bayan Saleh

Theses and Dissertations

Astrocytes are crucial in preserving the structural and functional integrity of the central nervous system (CNS). They participate in several physiological processes, such as the uptake of neurotransmitters, control of extracellular ion concentration, and preservation of the blood-brain barrier. Recent research has raised the possibility that astrocytes are also involved in the onset and development of Alzheimer's disease (AD). While the precise mechanisms underlying the development and progression of AD are not fully understood, recent research has suggested that age-related changes in the brain extracellular matrix (ECM) properties may play a critical role in the progression of the disease. Investigating …

Rattus Norvegicus As A Biological Detector Of Clandestine Remains And The Use Of Ultrasonic Vocalizations As A Locating Mechanism, Gabrielle M. Johnston

Master's Theses

In investigations, locating missing persons and clandestine remains are imperative. One way that first responder and police agencies can search for the remains is by using cadaver dogs as biological detectors. Cadaver dogs are typically used due to their olfactory sensitivity and ability to detect low concentrations of volatile organic compounds produced by biological remains. Cadaver dogs are typically chosen for their stamina, agility, and olfactory sensitivity. However, what is not taken into account often is the size of the animal and the expense of maintaining and training the animal. Cadaver dogs are typically large breeds that cannot fit in …

Self-Powered Triboelectric Mems Accelerometer, Mohammad Alzgool, Yu Tian, Benyamin Davaji, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

A self-powered triboelectric accelerometer miniaturized to the micro-scale is presented. This micro triboelectric accelerometer (MTEA) was fabricated using CMOS-compatible processes. The design followed the triboelectric nanogenerators made in meso-scale and operates in the contact-separation mode. The scaled-down, multilayer design enabled fabrication using microelectromechanical systems (MEMS) technology. The MTEA was made using an aluminum and polyimide triboelectric pair that generated charges on the contact. A square movable plate that is 2 mm x 2 mm was fabricated with 1 μm thickness. Then, the fabricated MTEA was excited by a mini-shaker at known frequencies (0.1–7 kHz) and accelerations (1–10 g), and the …

Markov Chain Analysis Comparison, Thomas Robert Prouty

Undergraduate Honors Capstone Projects

This Honors Capstone was proposed as a method to develop a greater understanding of modern model-checking tools. To do this the student chose to analyze and compare the results of the tools Prism, Storm, and Stamina. To evaluate the effectiveness of each tool, comparisons were made of the results for running each tool on a simplified communication network.

The simplified communication network model used was a CTMC (Continuous-Time Markov Chain) model that employed correct signal transitions and erroneous bit flipping transitions. This was done in an effort to simulate possible errors and faults that can occur between a provider and …

Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris

All Theses

Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 10⁵ and 2.14 x10⁶ years (Hu, 2010). Considering these characteristics, ⁹⁹Tc and ²³⁷Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …

Laser Inscribed Graphene Aptasensor For Detection Of Apple Stem Pitting Virus, Yifan Tang

All Theses

Apple stem pitting virus (ASPV) is a latent RNA virus that could cause significant loss to apple production; early-stage field diagnosis could reduce the economic loss caused by ASPV infection. Biosensor is a promising user-friendly detection tool that could transduce biological or chemical interactions into electric signals. Among various types of biosensors, aptasensor, which use aptamers as recognition elements show potential as a high throughput, in-field test. The goal of this thesis is to develop an electrochemical aptasensor testing system for ASPV detection. The quality control study of laser inscribed graphene (LIG) based working electrode of the biosensor was conducted …

Me-Em Enewsbrief, March 2023, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

The Synthesis And Characterization Of Metal Oxide Nanomaterial-Based Composites And Their Use As Antibacterial Agents, Jo A. Sanchez

Theses and Dissertations

The work presented in this thesis discusses the antibacterial properties of various metal oxides and metal oxide/polymer composite fibers. Polyvinylpyrrolidone (PVP) fibers embedded with Zinc Oxide nanoparticles (ZnO NPs) were prepared by centrifugal spinning from PVP aqueous solutions) and ZnO NPs. The ZnO NPs were synthesized and coated with different surfactants, cetyltrimethylammonium bromide (CTAB) and hexadecyltrimethylammonium bromide (HTAB). The effect of surfactant coating on the antibacterial activity of ZnO NPs and PVP/ZnO nanocomposite fibers against escherichia coli (e. coli) and bacillus megaterium (b. megaterium) bacteria was systematically investigated. The results showed that coating the ZnO NPs …

Piezoresistivity Of Electrically Conductive Asphalt Concrete, Mateo Schmit Mendoza

Theses and Dissertations

Electrically conductive asphalt concrete is considered as a multifunctional construction material due to its structural and non-structural functions. This study aims to investigate piezoresistivity of conductive asphalt concrete. Piezoresistivity is an electrical property of some materials which electrical resistivity changes with induced strain and subsequently, it has the potential for self-sensing smart technology. Graphite Powder F-516 with various contents was added into the asphalt mixtures to impart the electrical conductivity. Electrochemical impedance spectroscopy (EIS) was selected to measure the electrical properties of the specimens in dry and wet conditions, and low and high temperatures. The impedance measurement shows that the …

Low-Cost Microstereolithography 3d Printing With Microfluidic Microsampling Applications, Lauren Twombly

Chemistry & Biochemistry Undergraduate Honors Theses

The growing field of stereolithography 3D printing has welcomed a new age ofmicrofluidic device fabrication techniques. When compared to previous planar fabrication techniques such as soft-lithography, stereolithography 3D printing offers highly automated procedures, reduced fabrication times, and greater complexity of device features. To date, the greatest tradeoff for 3D printing in microfluidic device fabrication is poorer resolution when compared to soft-lithography which can produce feature sizes on the nanometer scale. The poorer resolution of 3D printing limits the feasible size of features. While highly sophisticated 3D printers are capable of achieving sub 10 μm resolution, these instruments are incredibly expensive …

Study Of The Stability Of Heparin/Collagen Layer-By-Layer Coatings, Hector M. Apodaca Reyes

Chemical Engineering Undergraduate Honors Theses

Pairing heparin with collagen-based medical implants has opened a whole new area of research for enhancing the desired effect of current implants. In fact, heparin (HEP) and collagen (COL) layer-by-layer (LbL) coatings have shown impressive results in forming polyelectrolyte multilayers. It has been already seen on skin grafts, nerve guide conduits (NGCs), and drug delivery devices yielding promising results. Due to being a simple, cost-efficient, and versatile option to fabricate thin biomimetic films, this self-assembly technique is one of the most effective methods to immobilize extracellular matrix (collagen and heparin) onto medical devices and implants. Even though previous studies have …

Lignin Copolymer Property Prediction Using Machine Learning, Collin Larsen

Chemical Engineering Undergraduate Honors Theses

Lignin, an abundant biopolymer, is a waste byproduct of the paper and pulp industry. Despite its renewable nature and potential applicability in various products, such as plastics and composites, the development of lignin-based materials has been impeded by the cumbersome, Edisonian process of trial and error. This research proposes a novel approach to forecasting the properties of lignin-based copolymers by utilizing a recurrent neural network (RNN) based on the Keras models previously created by Tao et al. Example units of modified lignin were synthesized via esterification and amination functional group modifications. To increase the efficiency and accuracy of the prediction …

Greenhouse Gas Emissions From Milk Production In The Us, Cailey Cooper

Chemical Engineering Undergraduate Honors Theses

Life cycle assessment is performed to determine the environmental impacts of the life cycle of a product. In this study, the greenhouse gas emissions from milk production in the United States were calculated using a cradle-to-gate analysis. The dairy industry has a noticeable impact on the total greenhouse gas emissions in the US. Performing life cycle assessment provides information about the main emission sources in the life cycle which can spark innovative changes to reduce these emissions. The life cycle assessment was performed using the openLCA software and ReCiPe impact assessment methodology. The results indicated that 1.28 kg of carbon …

Response Of Cell Nuclei To Mechanical Strain In Synthetic Liquid Crystals, Sydnee Ehorn

Chemical Engineering Undergraduate Honors Theses

In this research project, induced mechanical stress on the cell nucleus via synthetic liquid crystals (LCs) was explored. Points of interest were the shape alterations and distortions of the nuclear envelope under strain, providing insight into the mechanics and stiffness of the cell nuclei. LCs are substances with structure and fluidity, and LCs in the nematic phase are aligned in a single direction without layers, inducing shear stress on inclusions. This study confirmed that an aqueous solution of 17.3 wt% disodium cromoglycate (DSCG) can successfully strain the nuclei of chicken red blood cells (RBCs) by examining the nuclear response to …

Separation Of Organic Acids Through Direct Catalysis From Sugars, Katelyn Robinson

Chemical Engineering Undergraduate Honors Theses

Society relies on plastic products, whether they are single use or durable. A downside of plastic is that the most common type is a product of oil and oil is not only a limited resource but also a climate-damaging resource. Polylactic acid (PLA) is a bio-based, biodegradable plastic. However, the process of converting biomass to polylactic acid polymer has the largest environmental impact of the PLA production process, so alternative methods of conversion are needed (Moretti et al., 2021). The polylactic acid polymer can be made with lactic acid, which can be converted from glucose.

Photocatalytic Nanoparticle Treatment Of Cyanotoxins In Harmful Algal Blooms, Brian Baird

Civil Engineering Undergraduate Honors Theses

Harmful Algal Blooms (HAB) have the ability to cause detriment to water bodies, ecosystems, and human health. Furthermore, current evidence suggests that these events are becoming increasingly common due to factors such as increased pollution and global warming. While there are current methods to treat water that is negatively impacted by the bacteria and toxins associated with HABs, these methods are often costly and inefficient. The purpose of this research is to explore a potential treatment option that uses titanium dioxide photocatalytic nanoparticles attached to a retractable net to treat toxins produced by HABs in situ. Specifically, the toxin …

Radic Voice Authentication: Replay Attack Detection Using Image Classification For Voice Authentication Systems, Hannah Taylor

Undergraduate Honors Theses

Systems like Google Home, Alexa, and Siri that use voice-based authentication to verify their users’ identities are vulnerable to voice replay attacks. These attacks gain unauthorized access to voice-controlled devices or systems by replaying recordings of passphrases and voice commands. This shows the necessity to develop more resilient voice-based authentication systems that can detect voice replay attacks.

This thesis implements a system that detects voice-based replay attacks by using deep learning and image classification of voice spectrograms to differentiate between live and recorded speech. Tests of this system indicate that the approach represents a promising direction for detecting voice-based replay …

Trees Recommendation In Agroforestry Ecosystem Using Nlp, Omkar Sawant

Electronic Theses, Projects, and Dissertations

Agroforestry farming is one of the challenging sectors to grow the crops or farming or variety of trees from the ancient days due to erosion and desertification. This Culminating Experience Project explored how recommendation system can be developed and used in agroforestry. The research questions are Q1. What methods can be used to improve the accuracy and reliability of soil-based agroforestry tree species recommendation systems? Q2. How can agroforestry tree species recommendation systems be tailored to the needs of different stakeholders, such as smallholder farmers or agribusinesses? Q3. What will be the top three, tree recommendations using natural language processing …

Computational Modeling Of Patterned Membranes And Spacers For Improved Hydrodynamics And Fouling Reduction In Reverse Osmosis Water Treatment Processes, Zuo Zhou

All Dissertations

My research goal is to discover ways to improve the hydrodynamics of reverse osmosis (RO) membrane systems through creative membrane surface patterning and spacer designs. Since concentration polarization (CP) usually promotes membrane fouling, improving hydrodynamics would result in reduced fouling and better membrane performance. With computational fluid dynamics (CFD), we can explore dozens or even hundreds of models with different geometries and boundary conditions. Through plotting their velocity profile, streamlines, shear stress, pressure profile, concentration profile, and so on, we can determine which design would lead to the best performance.

At first, patterned membranes were evaluated and compared with flat …

Molecular Dynamics Simulation On Molybdenum Disulfide: Thermal-Mechanical Properties And Phase Transitions Under External Loading, Mahabubur Rahman

All Dissertations

Due to their remarkable properties, transition metal dichalcogenides (TMDs) have received much scientific interest throughout the past decade. Two layers of chalcogen atoms (S, Se, Te) sandwich a layer of transition metal atoms (Mo, W, Ta) to form the three-atom thick unit cell in TMDs. The interaction between TMD "single layers" is mediated by neighboring chalcogen planes and bonded by Van der Waals forces. Due to this weak out-of-plane interaction, bulk samples can be thinned down to a single layer by exfoliation. Among the TMDs, Molybdenum Disulfide (MoS₂) shows promise in the field of electronics, optics, and sensing …

3d Printing With Photopolymerizable Polyester Resins For Resorbable Medical Device Applications, Mathew Murphy Stanford

All Dissertations

In the past decade, the healthcare industry has seen a significant increase in the use of additive manufacturing (AM or “3D printing”) with subsequent improvement in clinical outcomes.As an exceptional AM technology, vat-photopolymerization (VP), often called stereolithography, can create complex structures and has thus been adopted for a range of biomedical applications including surgical guides, temporary implants, and resorbable tissue scaffolds.However, limitations remain in the availability of photopolymerizable resin materials with appropriate mechanical performance, biodegradability, and biocompatibility for application to resorbable medical devices.

The objective of this work was to employ novel photopolymerizable polyester-based macromers in the development of resorbable …