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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 …

Understand The Structure-Water-Responsive Relationship By Engineering Silk Materials, Yeojin Jung

Dissertations and Theses

Water-responsive (WR) materials mechanically swell and shrink in response to changes in relative humidity, and they have demonstrated the capability to exert higher actuation energy than conventional actuators and artificial muscles. As a result, WR materials have recently gained attention as potential high-energy actuating components for engineering applications. Despite the growing interest in this emerging category of WR materials, the fundamental WR mechanism of their significant performance is still not fully understood, limiting the ability to rationally design engineered systems. This dissertation presents three approaches for understanding the water-responsiveness of materials by engineering Bombyx (B.) mori silkworm silk protein. First, …

The Effect Of Nanoconfined Liquid Properties On The Water-Responsive Behavior Of Bacterial Cell Walls, Seungri Kim

Dissertations and Theses

Water-responsive (WR) materials have the ability to mechanically swell and shrink in response to changes in relative humidity (RH). These WR materials are used by many biological systems to perform essential tasks; for example, pinecones use WR materials to release their seeds in dry environments, and wheat awns open and close to propel seeds into the soil, driven by daily RH changes. The WR actuation of some biomaterials is extremely powerful, for example Bacillus subtilis cell walls display record-high actuation energy and power densities of 72 MJ m^-3 and 9.1 MW m^-3, surpassing those of all existing …

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.

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.

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

Journal of the Arkansas Academy of Science

No abstract provided.

Drop Retention And Departure In Adiabatic Shear Flow On Structured Superhydrophobic Surfaces, Blake M. Lyons, Daniel Maynes, Julie Crockett, Brian D. Iverson

Faculty Publications

Drops are retained or held on surfaces due to a retention force exerted on the drop by the surface. This retention force is a function of the surface tension of the liquid, drop geometry, and the contact angle between the drop and the surface. When external or body forces exceed the retention force, the drop begins to move. This work explores the conditions for which drop departure occurs on structured superhydrophobic surfaces in the presence of an applied shear flow. Drop departure is explored for five microstructured superhydrophobic surfaces, one nanostructured carbon nanotube surface and one smooth hydrophobic surface. Surface …

Advancing Natural Hydrogen Exploration: Headspace Gas Analysis In Water-Logged Environments, Krista Davies, Lionel Esteban, Alireza Keshavarz, Stefan Iglauer

Research outputs 2022 to 2026

Natural hydrogen has gained prominence as a potential contributor to the low-carbon energy landscape; however, exploration techniques are still evolving. Current methods primarily rely on dry soil gas studies or gas vent measurements. Because gas vents are scarce and groundwater inhibits hydrogen gas flux from the soil, other field detection techniques are necessary. This research paper presents a novel approach for advancing natural hydrogen exploration through the analysis of headspace gas of agitated groundwater extracted from dedicated shallow boreholes to better estimate the hydrogen gas flux and its variations with time. Several shallow boreholes were drilled in Western Australia on …

Design Of An Adaptive Robust Pi Controller For Dc/Dc Boost Converter Using Reinforcement-Learning Technique And Snake Optimization Algorithm, Seyyedmorteza Ghamari, Mojtaba Hajihosseini, Daryoush Habibi, Asma Aziz

Research outputs 2022 to 2026

The DC/DC Boost converter exhibits a non-minimum phase system with a right half-plane zero structure, posing significant challenges for the design of effective control approaches. This article presents the design of a robust Proportional-Integral (PI) controller for this converter with an online adaptive mechanism based on the Reinforcement-Learning (RL) strategy. Classical PI controllers are simple and easy to build, but they need to be more robust against a wide range of disturbances and more adaptable to operational parameters. To address these issues, the RL adaptive strategy is used to optimize the performance of the PI controller. Some of the main …

A Natural Hydrogen Seep In Western Australia: Observed Characteristics And Controls, Krista Davies, Emanuelle Frery, Ausama Giwelli, Lionel Esteban, Alireza Keshavarz, Stefan Iglauer

Research outputs 2022 to 2026

Natural hydrogen (H2) is a promising resource for the energy industry’s transition to zero-carbon fuels. However, its extent and feasibility for exploitation remain unclear. A key step towards discovering subsurface dihydrogen accumulations is detecting H2 seeps. This study presents the first autonomous, multi-gas monitoring of a natural hydrogen seep in Australia, where dihydrogen, carbon dioxide, and hydrogen sulphide were measured together. The research revealed significant H2 seepage on the Yilgarn Craton in Western Australia, with seasonal fluctuations: high emissions after dry summers and reduced emissions following rainfall due to increased groundwater levels. Groundwater appears to act as a seasonal inhibitor …

Laboratory Measurements Of Wave Transmission Through Oyster-Based Low Crested Breakwaters, Michael Andrew Roster

UNF Graduate Theses and Dissertations

Pervious Oyster Shell Habitats (POSH) are novel living shoreline components that were recently developed and deployed along several shorelines in northeast Florida. POSH units are designed to provide a breakwater using only recycled eastern oyster shell and Portland cement. However, the hydrodynamic performance of these unique structures had never been tested, so it was unclear how they affected wave energy. During this study, a series of laboratory experiments were conducted to compare wave attenuation from POSH units to wave attenuation from geometrically similar and commercially available Reef Balls^TM (specifically, the OysterBreak series of units). Experiments included a range of …

Leveraging Redundancy As A Link Between Spreading Dynamics On And Of Networks, Felipe Xavier Costa

Electronic Theses & Dissertations (2024 - present)

A constant quest in network science has been in the development of methods to identify the most relevant components in a dynamical system solely via the interaction structure amongst its subsystems. This information allows the development of control and intervention strategies in biochemical signaling and epidemic spreading. We highlight the relevant components in heterogeneous dynamical system by their patterns of redundancy, which can connect how dynamics affect network topology and which pathways are necessary to spreading phenomena on networks. In order to measure the redundancies in a large class of empirical systems, we develop the backbone of directed networks methodology, …

Removal Of Pfoa/Pfos In Water Using Electrocoagulation And Associated Life Cycle Impacts And Financial Costs, Tianhong Mu

Electronic Theses & Dissertations (2024 - present)

Electrocoagulation (EC) with a zinc anode demonstrated promising results to remove perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from an aqueous solution. However, the energy requirement for EC is usually very high due to water electrolysis or aeration. The second chapter of this dissertation aims to reduce energy consumption using an air-cathode in EC (ACEC) to supply oxygen electron acceptor without aeration for attenuating PFOA/PFOS in this new configuration. For the high PFOA concentration (0.25 mM), ACEC with 45 min of the reaction time exhibited an excellent PFOA removal (99.8 ± 0.3% removal) comparable to an EC with aeration (EC-aeration, …

Development Of Erosion Functions For Micp-Treated Beach Sand, Saeed Booshi

UNF Graduate Theses and Dissertations

This thesis investigates the effectiveness of microbially-induced calcium carbonate precipitation (MICP) using the recently introduced bioslurry treatment method via surface percolation. To simulate realistic water forcing conditions, a piston-style erosion rate testing apparatus, specifically the Florida Department of Transportation Sediment Erosion Rate Flume, was used. Initial tests conducted at a high shear stress of 42 Pa revealed that a combination of 15% bioslurry and 85% cementation solution exhibited the strongest erosion resistance when compared to other ratios between bioslurry and cementation solution. Subsequent experiments focused on separating the specimen into a "loose" part and a “surface crust,” with shear stresses …

Implementation Of Algorithms For Sorting By Strip Swaps Using Alternating Cycle Graphs, Harsh S. Bhakharia

UNF Graduate Theses and Dissertations

Challenges in computational biology, such as genome rearrangement, and applications in optical character recognition, like zoning techniques, often require solving optimization problems. These involve reordering scrambled sequences of numbers into a sequential arrangement known as the identity permutation.

Rearranging any given permutation into the identity permutation with the minimum number of specific operations related to strips gives rise to various combinatorial optimization scenarios. Operations such as strip moves, transpositions, reversals, and block interchanges have been extensively researched.

This thesis builds on the foundational work of Roy et al., targeting the refinement of their cycle graph algorithm for sorting by strip …

Integrating Therapy Into Play: Stand-On Ride-On For A Child With Cerebral Palsy, Kira Flanagan

UNF Graduate Theses and Dissertations

This study focuses on the development of an adaptive ride-on toy specifically designed for a 2.5-year-old child with spastic diplegic cerebral palsy. As a feasibility study, the primary objective of this innovative device is to enhance motor function, foster autonomy, and improve the overall quality of life for the child. The Power Mobility Device (PMD) integrates actuation and steering modifications, and a harness mechanism tailored to meet the child's unique needs. Comprehensive assessments of the child's spatiotemporal gait characteristics were conducted before and after a three-month usage period. The results reveal significant improvements in the child's ability to control dynamic …

Development And Characterization Of Ceramic Devices For Capillary Action In Microgravity For The Purpose Of Growing Vegetables In Space, Lucas S. Mougeot

UNF Graduate Theses and Dissertations

The future of humanity is often rendered in spectacular visions of a multiplanetary civilization with a booming space economy. Reaching this reality requires addressing one of the core needs of survival: food. Porous ceramics used for Passive Porous Tube Nutrient Delivery Systems (PPTNDS) offer a promising solution. In microgravity environments such as the International Space Station (ISS), fluid dynamics and liquid coagulation do not support conventional agricultural practices. Porous ceramic materials present a solution that enables nutrient solution diffusion via capillary action.

In this research, it was determined that extruding a wadding ceramic tube and sintering it at 1900 °F …

Development Of Tio2/Nh2-Mil-125 Nanocomposite For The Removal Of Ciprofloxacin Under Induced Solar Irradiation, Bilkis Mojisola Ajiwokewu

Theses

This research focuses on the development and application of Metal-Organic Frameworks (MOFs)-based nanocomposites for the photocatalytic removal of pharmaceutical contaminants, with a specific emphasis on ciprofloxacin (CIP). The photocatalytic degradation of CIP was investigated using as-synthesized photocatalysts of TiO₂ nanowires (TiO₂NWs), bare MOF of NH₂-MIL-125, TiO₂NW/NH₂-MIL-125 composite, and Lanthanum (La)-doped composite. Intriguingly, the TiO₂NW/NH₂-MIL-125 composite exhibited the highest efficiency, achieving a photodegradation rate of 0.0111 min-1, surpassing the independent performances of bare MOF of NH₂-MIL-125 and TiO₂NW. The observed efficiency was attributed to …

Development And Evaluation Of A Retrofittable Variable Rate Applicator Controller, Ahmed Abdalla

Electronic Theses and Dissertations

The need to optimize resource utilization while increasing crop productivity is paramount. This research proposes a Low-cost Retrofittable Variable Rate Applicator Controller (VRAC) that aims to leverage the adoption of Variable Rate Technologies. The controller operates via the Raspberry Pi platform, a Global Positioning System (GPS), a stepper motor drive, and an anti-slip wheel encoder. The VRAC allows precise, on-the-fly control of variable-rate application of farming inputs. It utilizes GPS with 10 cm accuracy to pinpoint geographic coordinates in real-time. A wheel encoder measures traveling speed with a slip-resistant wheel design for precise RPM readings. The Raspberry processes the data, …

Unlv Title Iii Aanapisi & Mcnair Scholars Institute Research Journal 2024, Jesica Godinez-Paredes, Kian Hassankhan, Apia Hickman, Robin Ruth Kee, Kevin Ayala Pineda, Briana Melendez, Kalli Ramos, Saturn L. Reyes, Fabian Leija, Selena Pepe, Silva Topchyan, Celeste Ainsley, Mayra Arzate, Jessica Balistreri, Zantana Ephrem, Mirella Jasso, Karl Panou, Nichole Pelaez, Miklo Alcala, Akshay Dave, Mey Mey Heng, Michael Finkle, Janessa Montenegro, Reynafe Naol Aniga, Victor Mejia, Angelica G. Diaz, Anayeli Flores-Garibay, Kari Lee Joe Goold, Samantha Hernandez, Lianelys Cabrera Martinez, Caitlin Reynolds, Kimberly N. Usbeck, Abdulrahman Alahdal, Angelica Diaz, Willaine Mae Kahano, Raquel Jackson, Cecia Ruiz-Hernandez, Kers Ung-Watson, Yessenia Henriquez, Vanessa Marie Booth, Alexia Brown, Darlyn Magana, Bianca Navarro, Nicholas Pereira, Gia Renemae Calip, Lucky Heng, Ralph Sagun, Lucas Abreu, Alexandra Maria Acosta, Tristan Benally, Cosset Hernandez Pena, Adrian Montenegro, Cierra Paaaina-Daquioag, Nicole Torosian, Tracy Fuentes, Julissa Martinez, Medina Mcallister, Michal Newhouse-Van Vlerin, Tiria Carr, Nima Abkenar, Isabella Aceituno, Yuhan Bi, Victoria Campos, Melika Cummings, Zachary J. Johnigan, Alexis Sotolongo-Marin

McNair Journal

Journal articles based on research conducted by undergraduate students in the AANAPISI, LSAMP, and McNair Scholars Program.

Table of Contents

About AANAPISI

Dr. Chris Heavey, Interim President

Dr. Keith Rogers, Vice President for Student Affairs

Ms. Zhanna Aronov, Associate Vice President for Retention & Outreach

A Review Of Textmining Techniques: Trends, And Applications In Various Domains, Hiba J. Aleqabie, Mais Saad Sfoq, Rand Abdulwahid Albeer, Enaam Hadi Abd

Iraqi Journal for Computer Science and Mathematics

Text mining, a subfield of natural language processing (NLP), has received considerable attention in recent years due to its ability to extract valuable insights from large volumes of unstructured textual data. This review aims to provide a comprehensive evaluation of the applicability of text mining techniques across various domains and industries. The reviewstarts off with a dialogue of the basic ideas and methodologies that are concerned with textual content mining together with preprocessing, feature extraction, and machine learning algorithms. Furthermore, this survey highlights the challenges faced at some stage in implementing textual content mining strategies. Additionally, the review explores emerging …

Perceptions Of Lightboard Videos On Engineering Students' Engagement For Learning: A Mixed-Methods Case Study, Rana Sanyal

Graduate Research Theses & Dissertations

Purpose. Researchers have recommended using comprehensive visual materials in engineering courses, as visuals instill more information in students than auditory information and they have the ability to engage students more effectively than other types of content and to convey the nuances of non-verbal communication. The purpose of this study was to explore the perceptions of engineering students on incorporating technologically advanced video course materials (TAVCM) created with lightboard technology on their engagement in learning. Theoretical Framework. The theoretical framework was based upon an integrative learning environment that incorporated many theories of cognitive learning. The Cognitive Theory of Multimedia Learning (CTML) …

Genetic Engineering Of Escherichia Coli For The Production Of Riboflavin, Adeyemi Adesanwo

Graduate Research Theses & Dissertations

Riboflavin, a water-soluble vitamin B2, is essential for the growth and reproduction of living organisms. However, humans and animals lack a riboflavin synthesis pathway and must rely on diets derived from plants and microbes for this essential vitamin. To meet our needs for vitamin B2, industrial riboflavin production is currently being pursued using strains of Bacillus subtilis. The fermentation process is successful, but improvements are needed for better substrate-to-product conversion yield. To this end, it is imperative to develop alternative microbial strains for cost-effective riboflavin production.

Due to its simple growth requirement, well-understood genetic background, and widely available genetic tools, …

Spin Wave Devices For Embedded Applications And Information Processing, Raisa Fabiha

Theses and Dissertations

Device miniaturization is a prerequisite for modern day electronics. Spintronics offers immense potential in energy efficient data storage, solid states devices, ultrafast computing and other electronic applications because of their low power consumption, non-volatile nature and unique activation mechanism. The conventional nano-antennas used for wireless communication, biomedical and wearable devices and IoT applications are limited by the traditional Harrington limit. As we attempt to miniaturize the antenna size beyond its emitted wavelength (also called “subwavelength” antenna), its gain and efficiency plummet. To overcome this challenge, the researchers have proposed magnetoelectric antennas. The ultra-thin film based magnetoelastic antennas suffer from eddy …

Enhancing Microwave Disinfection: Impact Of Sodium Chloride On Microbial Inactivation, Saleh A. Alfawaz, Ibrahim Nasser I. Alquaydheb, Amirreza Ghadimi Avval, Sara Ghayouraneh, Samir M. El-Ghazaly, Jianhong Zhou

Electrical Engineering and Computer Science Faculty Publications and Presentations

This study explores the role of sodium chloride (NaCl) in enhancing the efficiency of microbial inactivation using microwave energy with two distinct methods: temperature-controlled treatment and predefined cycle. The primary objective is to maintain a stable temperature within the biological samples during treatment. Detailed descriptions of the treatment system’s design and the function of each element are provided. Simulations are conducted to illustrate the heating behavior of liquids with and without NaCl, revealing significant differences in temperature profiles between the two media. The experimental design and the objective behind each iteration are discussed. The experimental design includes three different power …

Advancements In Sarcoma- And Nerve-Specific Fluorescence Imaging For Surgical Guidance, Kendra A. Hebert

Dartmouth College Master’s Theses

Fluorescence guided surgery (FGS) is an evolving field that aims to improve patient outcomes by using fluorophores to identify important tissues during surgery, such as tumors and nerves. In this thesis work, we explored different methods of identifying nerve and tumor tissues for FGS and a novel fluorescence-based method to determine the depths of these structures.

Researchers have explored using fluorescence guided surgery for surgical resection of cancerous tissues, including recent work by our group focusing on identifying soft tissue sarcomas with ABY-029, an epidermal growth factor receptor targeting probe. However, our preclinical and clinical work shows no single reporter …

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 …