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Actuator Optimization And Control Of Pediatric Knee Exoskeleton For Community-Based Mobility Assistance: More Lightweight, More Affordable, And More Stable, Sainan Zhang

Dissertations and Theses

Lightweight and smart exoskeletons offer the potential to improve mobility in children. State-of-the-art pediatric exoskeletons are typically clinic-based since they are either tethered or portable but cumbersome, and their design is often not optimized across a range of environments and users. Child growth progressively alters key exoskeleton design requirements, yet no prior work investigated actuator optimization to accommodate child growth. Moreover, exoskeletons typically use the torque sensor or spring mechanics as exteroceptive feedback, but these torque sensing methods not only lead to extra cost and mass but also cause a small range of stable controller gains.

To facilitate pediatric exoskeleton …

Mechanisms For Regenerative Intervertebral Disc Healing During Early Growth In Mice, Danielle N. D'Erminio

Dissertations and Theses

Annulus Fibrosus (AF) defects of intervertebral discs (IVDs) cause painful disability, for example when herniated tissue compresses against adjacent nerves. Discectomy, the current standard of treatment to address herniation, does not repair AF defects and can result in re-herniation and recurrent pain. As such there is a need for improved AF repair strategies. It has previously been established that neonatal mice functionally regenerate following severe AF injury providing a model of successful innate AF repair processes that contrasts the poor healing of adult mice. This dissertation focuses on identifying mechanisms of AF regenerative healing in neonatal mice subjected to severe …

Understanding The Impacts Of Extreme Weather On The Power Transmission Infrastructure: A Machine Learning Approach To Quantifying Risks And Enhancing Grid Resilience, Juan P. Montoya Rincon

Dissertations and Theses

This doctoral dissertation focuses on the resilience of power transmission infrastructure in tropical coastal environments, particularly in the face of extreme weather events such as hurricanes. The research is anchored on the case of the passage of Hurricane Maria in the Island of Puerto Rico in September of 2017 which caused the largest damage on the power infrastructure in US history. As such, the research investigates the interaction between extreme winds and power transmission infrastructure in complex terrain, aiming to quantify and predict power loss and damage to the infrastructure during such events. The study employs a comprehensive approach combining …

Keynote Address And Meeting Program, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Instructions To Authors, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Table Of Contents, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Business Meeting Report (Secretary's And Treasurer's Report), Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Journal Acknowledgements And Editorial Board, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Academy Presidents And Institutional Members, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Journal Of The Arkansas Academy Of Science Volume 78, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

Assessing The Condition Of Pavements (Road Surfaces) Using Computer Vision & Machine Learning, Syed Ibrahim Hassam

Doctoral

Regular inspections of pavements are conducted by civil infrastructure departments to evaluate the surface condition. Pavement surfaces are subject to deterioration caused by several factors such as traffic, weather, and sunlight. This deterioration becomes evident through various distresses, including potholes, rutting, cracking, bleeding, patching, and ravelling, which gradually affects the surface layer over time. It is essential to assess the condition of pavements as it not only ensures their usability but also maximises public safety. Effective pavement maintenance requires substantial resources and capital investment to carry out the most suitable maintenance treatments at the optimal time. Furthermore, the outcomes of …

Evaluation Of The Physicochemical Properties And Soil Biogeochemistry Of Fire Residues, Lingqun Zeng

Electronic Theses & Dissertations (2024 - present)

Wildland fire is a main driving force in the Earth system and affects ecosystem properties and processes across spatio-temporal scales. The burning of biomass and production of solid fire residues (conventionally termed fire ash) that are a mixture of completely and incompletely burned materials (inorganic ash and pyrogenic carbon), represent the direct and prominent changes by fires. Cycling of the fire residues is an integral component of elemental cycles and can mediate other biogeochemical processes.

This dissertation aims to fill important knowledge gaps in understanding the disturbance of wildland fires to biogeochemical processes in soils. First, this work characterized and …

Assessing The Potential Of Uav-Based Multispectral And Thermal Data To Estimate Soil Water Content Using Geophysical Methods, Yunyi Guan, Katherine R. Grote

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Knowledge of the soil water content (SWC) is important for many aspects of agriculture and must be monitored to maximize crop yield, efficiently use limited supplies of irrigation water, and ensure optimal nutrient management with minimal environmental impact. Single-location sensors are often used to monitor SWC, but a limited number of point measurements is insufficient to measure SWC across most fields since SWC is typically very heterogeneous. To overcome this difficulty, several researchers have used data acquired from unmanned aerial vehicles (UAVs) to predict the SWC by using machine learning on a limited number of point measurements acquired across a …

Hybrid Triboelectric-Piezoelectric Nanogenerator For Long-Term Load Monitoring In Total Knee Replacements, Mahmood Chahari, Emre Salman, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

A self-powered and durable pressure sensor for large-scale pressure detection on the knee implant would be highly advantageous for designing long- lasting and reliable knee implants as well as obtaining information about knee function after the operation. The purpose of this study is to develop a robust energy harvester that can convert wide ranges of pressure to electricity to power a load sensor inside the knee implant. To efficiently convert loads to electricity, we design a cuboid-array-structured tribo-pizoelectric nanogenerator (TPENG) in vertical contact mode inside a knee implant package. The proposed TPENG is fabricated with aluminum and cuboid-patterned silicone rubber …

Towards Self-Powered Load Imbalance Detection For Instrumented Knee Implants Using Quadrant Triboelectric Energy Harvesters, Mahmood Chahari, Hoesin Haghshenas, Emre Salman, Milutin Stanacevic, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

In this study, we proposed a triboelectric nanogenerator (TENG) as a pressure sensor to measure the load imbalance on the tibial tray. To detect the load imbalance, we proposed a segmented quadrant design. The TENG pressure sensors with various micro-patterns, including pyramid, cylindrical, and bar patterns, are utilized to measure the axial forces with different sensitivity in different quadrants of the tibial tray. The functionality of the instrumented implant is examined through experimental testing on the package, evaluating its sensing capabilities and power harvesting. The relationship between each quadrant output and the axial force is determined, which enables characterizing the …

Functionalized Microfiltration Membranes For Aerosol Capture To Chloro-Organic Degradation, Rollie George Mills

Theses and Dissertations--Chemical and Materials Engineering

The environmental remediation of water and air sources is a challenging field, due to widespread contamination, pollutant variety, and efficiency of existing treatment options. Remediation of certain pollutants, such as per- and polyfluorinated chemicals (PFAS), polychlorinated biphenyls (PCBs), volatile organic compounds (VOCs), and viral aerosols, has shown promise via adsorptive, degradative, or filtration-based processes, each with their respective advantages and limitations. Membrane technology is one option that has exhibited considerable pollutant removal from environmental sources via reverse osmosis (RO) filtration, but is limited by low permeabilities and lack of pollutant detoxification. With the support of NIEHS and NSF, the functionalization …

Exploring The Effect Of Casting Solution Composition, Additives, And Casting Conditions On The Morphology And Separation Performance Of Pvdf Membranes, Rachel Kaplan

Theses and Dissertations--Chemical and Materials Engineering

Global water scarcity and quality concerns in the past decade have led to a looming global water crisis. Polymeric membranes have emerged as a potential solution due to their modularity, operational reliability, and wide range of contaminant removal. Polyvinylidene fluoride (PVDF) is often selected as a membrane material for its enhanced chemical resistance, thermal stability, and mechanical strength. However, these membranes often require more complex fabrication methods or support materials to achieve optimum performance. Flat-sheet unsupported PVDF membranes were fabricated via nonsolvent induced phase separation. The influence of solvent, polymer composition, pore forming additives, and casting conditions were explored with …

Development Of Glutathione-Responsive Disulfide-Containing Poly(Beta-Amino Esters) With Varied Hydrophilicity And Acrylate Functionality, Anastasiia Aronova

Theses and Dissertations--Chemical and Materials Engineering

Smart biomaterials are becoming promising for therapeutic deliveries due to their ability to respond to changes in the environment. Redox-responsive hydrogels are a promising type of smart polymer that can swell and degrade according to cellular oxidative stress levels. Glutathione, abundant in cells, is crucial in redox-responsive biomaterials, serving as a key reactive molecule. This study explored the degradation kinetics of glutathione-responsive poly(β-amino ester) (PBAE) polymers created through a single-step Michael addition. We examined how disulfide content influences the degradation kinetics of these PBAE networks. Additionally, we investigated how the hydrophilicity and functionality of acrylate affect the degradation of disulfide-containing …

Sustained Release Systems For Endometrial Cancer, Claire E. Rowlands

Theses and Dissertations--Chemical and Materials Engineering

Endometrial cancer (EC) is the sixth most common cancer in women worldwide and is the most common cancer of female reproductive organs. From 2007-2016 there has been a global rise in incidence of EC of 1.3 %. Typically, EC is treated with surgery, but at later stages surgery is less effective requiring chemotherapy and/or radiation therapy. These treatment options are less effective than surgery and there are very few FDA approved chemotherapies for EC. The minuscule number of effective treatment options as well as an increase in incidence shows the need for creating improved treatments for EC. There has been …

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

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Biom 1720: Introduction To Biomedical Engineering Tools, Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Use of computer tools for data analysis, presentation, documentation; introduction to programming; individual and group design projects.

Modeling The Radiation Shielding Effectiveness Of Hafnium Diboride Reinforced Epoxy Composites Using Mcnp, Randolph Snook

Theses and Dissertations

This thesis uses MCNP simulations to evaluate the performance of a radiation shielding material consisting of Hafnium Diboride (HfB₂) powder in an epoxy matrix. Comparing the results to previously measured data against both gamma and neutron sources, suitability for other applications can be confirmed. The model simulated the epoxy material with different weight percentages of HfB₂ and thicknesses. It was compared to other shielding materials such as pure epoxy and 5% Borated High Density Polyethylene (HDPE-B). The HfB₂-epoxy composite was tested against a wide energy range gamma spectrum from a ¹⁵²Eu source, and neutrons …

Explore Security And Machine Learning Applications In Next Generation Wireless Networks, Haolin Tang

Theses and Dissertations

Next-generation (NextG) or Beyond-Fifth-Generation (B5G) wireless networks have become a prominent focus in academic and industry circles. This is driven by the increasing demand for cutting-edge applications such as mobile health, self-driving cars, the metaverse, digital twins, virtual reality, and more. These diverse applications typically require high communication network performance, including spectrum utilization, data speed, and latency. New technologies are emerging to meet the communication requirements of various applications. Intelligent Reflecting Surface (IRS) and Artificial Intelligence (AI) are two representatives that have been demonstrated as promising and powerful technologies in NextG communications. While new technologies significantly enhance communication performance, they …

Towards The Automation Of Post-Processing Of Additive Manufacturing Using Collaborative Robots, Logan Schorr

Theses and Dissertations

Despite the incredible potential that collaborative robots have, they are underutilized in several industries that could benefit greatly. These specialized fields, such as additive manufacturing, face challenges that can be solved with the use of robotics, including advanced computer vision, end-effector tooling, and process refinement. My research aims to utilize collaborative robots in an effort to solve the above stated problems, for the specific fields of additive manufacturing. Specifically within this field is the automation of post-processing; this is normally completely manual, as the tools for automation are not sufficiently developed to handle the flexibility required for additive manufacturing. This …

Open-Ended Hollow Coaxial Cable Resonance Sensing Via Permittivity Fluctuations For Applications To Exhaled Breath Health Monitoring, Peter Henry Holtmann

Masters Theses

"We report a pre-diagnostics breath analyzer based on the open-ended hollow coaxial cable resonator (OE-HCCR) to achieve real-time differentiation of healthy and compromised lung function through electromagnetic analysis of exhaled breath matter. A two-phase amplification scheme of electromagnetic signatures metered via the S11 phase curve offers high sensitivity to permittivity fluctuations in exposed airflow. The mathematical model of the breath analyzer is explained, followed by experimental validation of numerical findings from previous work. The collection of breath transient signals is performed through monitoring the reflected power magnitude and phase of the scattering parameter (S11) at the resonance frequency. Material fluctuations …

Investigation Of The Relationships Between Hydraulic, Physical, And Biological Soil Parameters At A Vineyard In Saint James, Missouri, Lyndsey Bennett

Masters Theses

"Soil is a living, dynamic system that performs vital functions such as crop production, organic matter decomposition, and the flow and transport of water. Given the pressures of food and in some locales water security, climate change, and sustainability, farmers, scientists, and other related specialists and stakeholders must have access to understandable soil health indicators as well as the soil hydraulic function parameters to maximize crop growth while maintaining soil health. Although biological and physical soil parameters are different, we aim to evaluate their relationship at the field scale. Hydraulic conductivity in the vadose zone may be especially important, as …

Production Of Glass-To-Metal Seals Using Additive Manufacturing Techniques, Aaron Read

Masters Theses

"Glass-to-metal (GtM) seals are hermetic barriers between glass and metal components, often used in the electronic and vacuum industries. Creating the seals traditionally requires heating all the components to the glass melting temperature, where the glass will flow and bond to the metal. Due to the manufacturing constraints of the individual components and sealing conditions there are geometric and material restrictions. Additive manufacturing techniques were used to make GtM seals to reduce these restrictions.

Hermetic, single pin seals were produced using printed metal shells, by selective laser melting (SLM), and digital light processing (DLP) printed glass preforms. Glass preforms were …

Discrete Event Simulation (Des) In Swapping/Charging Of Battery Electric Vehicles In Underground Mining, Albert Einstein Amponsem

Masters Theses

"With climate change concerns escalating, international agreements such as the Kyoto Protocol, the US Presidential Policy, and the Paris Agreement aim to reduce greenhouse gas (GHG) emissions, targeting significant reductions by 2050. The mining sector, a notable contributor to GHG emissions primarily through diesel-powered material haulage, emits approximately 68 million tons of CO₂ annually. Transitioning to Battery Electric Trucks (BETs) presents a viable mitigation strategy by replacing diesel trucks with electric alternatives, thus eliminating CO₂ emissions.

However, the effectiveness of BETs hinges on optimized battery swapping and charging procedures. This study employs Discrete Event Simulation (DES), a computational …

Modeling And Performance Evaluation Of Traditional And Ai-Based Mppt Techniques For Photovoltaic Systems., Md Badruddaza

Graduate Research Theses & Dissertations

The efficiency levels to convert from sunlight to electricity are in the range up to 22% commercially, based on the technology used. Due to comparatively low efficiency of photovoltaic systems, it is imperative to extract maximum power from the PV module array. Thus, in solar PV system, tracking the module’s MPP (maximum power point) is crucial and at the same time challenging as well due to varying climatic conditions. This research focuses on the modeling and performance evaluation of traditional Maximum Power Point Tracking (MPPT) techniques and AI-Based MPPT algorithms in photovoltaic systems. It addresses the issue of dynamic adjustment …

Bidirectional In-Situ Analysis And Visualization Of Fluid Structure Interactions With Applications In Blood Flow, Nazariy Tishchenko

Graduate Research Theses & Dissertations

Interactive blood flow simulation has applications in the understanding of complex fluids,training medical professionals, diagnostics, and surgical procedure planning. Bidirectional in situ visualization and analysis are much needed to streamline the analysis of large-scale patient-specific blood flow simulations. The in situ component ensures the live visualization of the simulation results while the simulation is running, and the bidirectional component allows for real-time control and configuration of the simulation parameters (i.e., setting and retrieving the simulation parameters and data based on need). In this project, a highly accurate multiphysics simulation was instrumented to work with an existing bidirectional in situ framework. …