Engineering Commons^™

Recent Advances In Solar Photo(Electro)Catalytic Nitrogen Fixation, Jun-Bo Ma, Sheng Lin, Zhiqun Lin, Lan Sun, Chang-Jian Lin

Journal of Electrochemistry

Ammonia (NH₃) is an essential chemical in modern society. It is currently produced in industry by the Haber-Bosch process using H₂ and N₂ as reactants in the presence of iron-based catalysts at high-temperature (400–600 ^oC) and extremely highpressure (20–40 MPa) conditions. However, its efficiency is limited to 10% to 15%. At the same time, a large amount of energy is consumed, and CO₂ emission is inevitably. The development of a sustainable, clean, and environmentally friendly energy system represents a key strategy to address energy crisis and environmental pollution, ultimately aiming to achieve carbon neutrality. …

Integrated Process Modeling, Techno-Economic Analysis And Life Cycle Assessment For Enhanced Biogas-To-Energy Sustainability And Efficiency, Rarosue Jennifer Amaraibi

USF Tampa Graduate Theses and Dissertations

This dissertation aims to enhance the cost competitiveness and minimize the environmental footprint of technologies that convert biogas to energy, contributing to global climate change mitigation efforts. Biogas, a by-product of the anaerobic decomposition of organic waste from various sources, is a renewable energy source with the potential to reduce carbon emissions and meet local energy needs. However, widespread adoption requires the development of economically viable and environmentally friendly technologies.The central hypothesis of this dissertation suggests that by adopting a holistic strategy that combines cutting-edge techniques to purify biogas and improve its conversion into valuable liquid fuels, we can substantially …

Electrospun Nanofiber Technology Based Energy Storage And Biosensor Devices For Wearable Electronics, Bianca Seufert

USF Tampa Graduate Theses and Dissertations

As progress in the field of nanotechnology continues to evolve, it is becoming more and more prevalent to apply this small but powerful technology to portable wearable electronics. The unique scale of such a technology lends its expertise to the investigation of enzymes for biometric related diagnostics or in the development of light weight flexible energy storage devices. Furthermore, as the need for highly precise and durable wearable electronics grows, the next generation of electronics must keep pace with this development in terms of shape, flexibility, functionality, and performance.

The presented research reviews the current state of art of nanofiber …

A Gateway To Next-Generation Patient Monitoring System, Kishore Kumar Kadari

USF Tampa Graduate Theses and Dissertations

Healthcare patient monitoring is undergoing a significant digital transformation, and the integration of Cyber-Physical Systems (CPS) and Artificial Intelligence (AI) is becoming increasingly crucial in reshaping patient care. In an era where digital technology is revolutionizing medical practices, this research aims to take a leading role in advancing a fundamental aspect of predictive and sustainable healthcare practices, enhancing patient outcomes and uplifting the practice of medicine.

This research focuses on the study of Digital Twins for precision health, which are designed to monitor and provide intricate, personalized feedback dynamically during a patient's healthcare experience. The architecture of the system is …

Development Of Novel Algorithms For The Investigation Of Small Displacement Optical Flow For Opto Kinetic Nystagmus (Okn) Detection And Large Displacement Optical Flow For Surveillance, Jaiseeli C

Theses and Dissertations

Motion is a significant component of the modern visual experience, aiding with oculomotor control, object recognition, scene interpretation, perceptual organization and the acquisition of 3D shapes. Identifying motion vectors that characterize two-dimensional image transitions, usually from video frames, is necessary to estimate motion.

Optical flow is a motion-tracking technique that estimates the trajectory and velocity of a moving object in a video by shifting each pixel between frames using displacement vectors. This work has two objectives based on small and large displacement optical flow and computes optical flow using Lucas-Kanade and Brox flow, which seem to be superior to other …

A Comparison Of Beamforming Characteristics In Isotropic And Composite Plate Structures For Use In Structural Health Monitoring, Sarah Ketchersid

Doctoral Dissertations and Master's Theses

Structural health monitoring in plate-like simple structures using phased array beamsteering of guided Lamb waves is useful in damage detection and evaluation efforts. Lamb waves can be effectively used for beamsteering using a linear array. The experimentation primarily focuses on beamsteering in the aluminum panel, which involves developing a simulation based on extracted data to visualize the dispersion of waves across the panel. By evaluating parameters such as slowness, velocity, and amplitude direction and variation for a specific metallic plate, the wavefront generated by a single wave source can be represented as a function of propagation angle and distance from …

Advancements In Characterization Of Ancient Potteries From Southeast Asia: A Review Of Analytical Techniques, Chitnarong Sirisathitkul

Makara Journal of Science

Ancient potteries offer valuable information regarding technological advancements, life dynamics, cultural diversity, and trade routes in the past. Earthenware, stoneware, and porcelain from Southeast Asia have been characterized using several analytical techniques, as reviewed in this article. Fluorescent and diffracted X-rays give rise to elemental and phase compositions, respectively. Examination of molecular bonds requires vibrational spectroscopy, which is useful for the identification of organic materials in ancient potteries. With the advent of portable X-ray fluorescence and Raman spectrometry, on-site analysis of archeological ceramics is now possible. For in-depth analysis, synchrotron light sources can provide new insights into artifacts through X-ray …

Image Filtering To Improve Maize Tassel Detection Accuracy Using Machine Learning Algorithms, Eric Rodene, Gayara Demini Fernando, Ved Piyush, Yufeng Ge, James C. Schnable, Souparno Ghosh, Jinliang Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Unmanned aerial vehicle (UAV)-based imagery has become widely used to collect timeseries agronomic data, which are then incorporated into plant breeding programs to enhance crop improvements. To make efficient analysis possible, in this study, by leveraging an aerial photography dataset for a field trial of 233 different inbred lines from the maize diversity panel, we developed machine learning methods for obtaining automated tassel counts at the plot level. We employed both an object-based counting-by-detection (CBD) approach and a density-based counting-by-regression (CBR) approach. Using an image segmentation method that removes most of the pixels not associated with the plant tassels, the …

Rfi Mitigation And Discrete Digital Signal Processing Rfsoc Algorithm Implementations For Radio Astronomy And Wideband Communication Systems, Devon Christopher Ward

Theses and Dissertations

Due to the massive increase of active transmitters broadcasting over wideband frequencies, such as 5G wireless systems, LEO/MEO satellites, satellite constellations, and the increase of IoT devices in the average home, the radio frequency spectrum is becoming more and more congested by interference. Passive receivers face additional challenges due to the growing use of wideband frequency transmissions aimed at boosting communication system throughput. As a result, passive receivers must adopt more robust and intricate techniques to mitigate radio frequency interference. A proposed RFI removal system, known as the true time delay Hadamard projection algorithm, has been introduced in previous work …

The Determination Of Pzc And Differential Capacitance Curve Of Platinum-Alkaline Polymer Electrolyte Interfaces, Chen-Xi Liu, Ze-Ping Zou, Mei-Xue Hu, Yu Ding, Yu Gu, Shuai Liu, Wen-Jing Nan, Yi-Chang Ma, Zhao-Bin Chen, Dong-Ping Zhan, Qiu-Gen Zhang, Lin Zhuang, Jia-Wei Yan, Bing-Wei Mao

Journal of Electrochemistry

Alkaline polymer electrolyte (APE) is the core component of modern alkaline hydrogen and oxygen fuel cells, and its single ion conductor nature makes the "electrode/APE" interfaces different from the conventional "electrode/solution" interfaces in terms of ion distribution, electrical double layer structure and polarization behavior. Due to the complexity of the APE and the associated solid-solid interfaces, fundamental investigations are challenging and deeper understanding of the structures and properties of such interfaces is in the infant stage. In this work, we aim to investigate the double layer structure from the aspects of differential capacitance curve and potential of zero charge (PZC) …

Development Of Data-Driven Models To Predict Chemical Dosage And Energy Intensity For Different Supply Sources Of Drinking Water, Rehnuma Salsavil

USF Tampa Graduate Theses and Dissertations

As part of the UN Sustainable Development Goals (SDG6), access to clean water for the entire population and sustainable management of water resources have been stressed. Demand for water is increasing due to population growth, economic development, water quality degradation, and climate change. More water needs to be produced for the community at lower treatment costs. The chemical dosage and energy intensity are two important factors that influence water treatment costs and sustainable management of resources as well.

Previously, chemical dosage modeling to reduce treatment costs have been explored but there have been more focus in coagulant dosage modeling. Other …

The History And Explanation Of Stormwater Ponds In East Tampa, Natasha Sutton

USF Tampa Graduate Theses and Dissertations

The overall goal of this research was to explore and understand the history of stormwater ponds in the East Tampa Community Redevelopment Area (CRA), a 4,800-acre urban community comprising many different historic African American neighborhoods in Florida's City of Tampa. Seen as one of the most affordable stormwater management solutions in southeastern parts of the United States, stormwater ponds dot the East Tampa landscape. As the manager of CRA funds, the City of Tampa stands out as a main decision maker around the stormwater ponds within the East Tampa CRA. Over the years the stormwater ponds have generated much interest …

Human Motion-Inspired Inverse Kinematics Algorithm For A Robotics-Based Human Upper Body Model, Urvish Trivedi

USF Tampa Graduate Theses and Dissertations

The goal of this research is to develop a human motion-inspired inverse kinematics algorithm framework specifically designed for a Robotics-Based Human Upper Body Model (RHUBM). This framework offers solutions to challenges in various fields. In humanoid robotics, the framework addresses the problem of unnatural robot movement by enabling the development of motion planning algorithms that incorporate human-like movements. For prosthetics, the framework tackles the challenge of amputee difficulty in learning and controlling prosthetics by providing a user-friendly interface that predicts and visualizes upper limb movements, enabling learning and practice. In rehabilitation therapy, the framework tackles …

Casar Public Lecture: "Women & Stem Education In Egypt & The Us: Stepping Into A Man's World Of Science & Technology", The Prince Alwaleed Center For American Studies And Research Casar, Yasmeen El Ghazaly, Mark W. Deets

Performances, Events, and Presentations

In celebration of International Women's Day this Month, we held a public lecture titled: "Women & STEM Education in Egypt & the US : Stepping into a Man's World of Science & Technology " on Thursday March 28th, 2024 from 12:15 pm to 1:15 pm (assembly hour) – Conference and Visitor Center, Mary Cross Hall AUC New Cairo Despite a plethora of advances made by women in the world we live in today, they are still woefully underrepresented in the realm of STEM education and the associated career paths. At this event, we uncovered the history, reasons & challenges women …

Micropatterning And Functionalization Of Single Layer Graphene: Tuning Its Electron Transport Properties, Miao-Miao Cui, Lian-Huan Han, Lan-Ping Zeng, Jia-Yao Guo, Wei-Ying Song, Chuan Liu, Yuan-Fei Wu, Shi-Yi Luo, Yun-Hua Liu, Dong-Ping Zhan

Journal of Electrochemistry

As a promising 2D material, graphene exhibits excellent physical properties including single-atom-scale thickness and remarkably high charge carrier mobility. However, its semi-metallic nature with a zero bandgap poses challenges for its application in high-performance field-effect transistors (FETs). In order to overcome these limitations, various approaches have been explored to modulate graphene's bandgap, including nanoscale confinement, external field induction, doping, and chemical micropatterning. Nevertheless, the stability and controllability still need to be improved. In this study, we propose a feasible method that combines electrochemical bromination and photolithography to precisely tune the electron transport properties of single layer graphene (SLG). Through this …

Effect Of Fabrication Parameters On The Ferroelectricity Of Hafnium Zirconium Oxide Films: A Statistical Study, Guillermo A. Salcedo, Ahmad E. Islam, Elizabeth Reichley, Michael Dietz, Christine M. Schubert Kabban, Kevin D. Leedy, Tyson C. Back, Weison Wang, Andrew Green, Timothy S. Wolfe, James M. Sattler

Faculty Publications

Ferroelectricity in hafnium zirconium oxide (Hf_1−xZr_xO₂) and the factors that impact it have been a popular research topic since its discovery in 2011. Although the general trends are known, the interactions between fabrication parameters and their effect on the ferroelectricity of Hf_1−xZr_xO₂ require further investigation. In this paper, we present a statistical study and a model that relates Zr concentration (x), film thickness (t_f), and annealing temperature (T_a) with the remanent polarization (P_r) in tungsten (W)-capped Hf_1−xZr_xO₂. …

Bear Lake Session, Lawrence Culver, Ben Shaw, Wesley Matthis, Mario Harper

Spring Runoff Conference

No abstract provided.

Predicting The Rate Of Degradation Related To Oxygen Electrode Delamination In Solid Oxide-Ion Electrolyzers, Yeting Wen, Kevin Huang

Faculty Publications

Language comprehension is often affected in individuals with post-stroke aphasia. However, deficits in auditory comprehension are not fully correlated with deficits in reading comprehension and the mechanisms underlying this dissociation remain unclear. This distinction is important for understanding language mechanisms, predicting long-term impairments and future development of treatment interventions. Using comprehensive auditory and reading measures from a large cohort of individuals with aphasia, we evaluated the relationship between aphasia type and reading comprehension impairments, the relationship between auditory versus reading comprehension deficits and the crucial neuroanatomy supporting the dissociation between post-stroke reading and auditory deficits. Scores from the Western Aphasia …

Understanding Effective Elastic Properties And Stress-Strain Evolution In Composite Granular Rocks Using Discrete Element Modeling, Prasad Pothana, Fernando E. Garcia, Kegang Ling

Petroleum Engineering Posters and Presentations

The mechanical behavior of composite granular rocks is a multifaceted phenomenon relevant to various geoengineering applications. Traditional homogenization models and continuum mechanics-based numerical methods often fall short of accurately capturing the intricacies of granular materials. Granular materials exhibit heterogeneity and arching mechanisms governing the force networks that ensure system stability. Unlike continuum-based approaches, particulate discrete element methods have an advantage in assessing effective material properties by considering material heterogeneity and grain-level physical interactions. This study evaluates effective elastic properties using particle flow code using flat-joint contact law for composite binary mixtures with a stiff inclusion embedded within a matrix material. …

Investigation Of Gas Dynamics In Water And Oil-Based Muds Using Das, Dts, And Dss Measurements, Temitayo S. Adeyemi

LSU Master's Theses

Reliable prediction of gas migration velocity, void fraction, and length of gas-affected region in water and oil-based muds is essential for effective planning, control, and optimization of drilling operations. However, there is a gap in our understanding of gas behavior and dynamics in water and oil-based muds. This is a consequence of the use of experimental systems that are not representative of field-scale conditions. This study seeks to bridge the gap via the well-scale deployment of distributed fiber-optic sensors for real-time monitoring of gas behavior and dynamics in water and oil-based mud. The aforementioned parameters were estimated in real-time using …

Photoswitchable Optoelectronic Properties Of 2d Mose2/Diarylethene Hybrid Structures, Sewon Park, Jaehoon Ji, Connor Cunningham, Srajan Pillai, Jean Rouillon, Carlos Benitez-Martin, Mengqi Fang, Eui-Hyeok Yang, Joakim Andreasson, Jeong Ho You, Jong Hyun Choi

Purdue University Libraries Open Access Publishing Fund

The ability to modulate optical and electrical properties of two-dimensional (2D) semiconductors has sparked considerable interest in transition metal dichalcogenides (TMDs). Herein, we introduce a facile strategy for modulating optoelectronic properties of monolayer MoSe2 with external light. Photochromic diarylethene (DAE) molecules formed a 2-nm-thick uniform layer on MoSe2, switching between its closed- and open-form isomers under UV and visible irradiation, respectively. We have discovered that the closed DAE conformation under UV has its lowest unoccupied molecular orbital energy level lower than the conduction band minimum of MoSe2, which facilitates photoinduced charge separation at the hybrid interface and quenches photoluminescence (PL) …

Existence Of A Nonzero Worst-Case Ach For Short-Term Exposure In Ventilated Indoor Spaces, K. A. Krishnaprasad, ‪Nadim Zgheib, K. Choudhary, M. Y. Ha, C. Y. Choi, K. S. Bang, S. Jang, S. Balachandar

Mechanical Engineering Faculty Publications

A well-ventilated room is essential to reduce the risk of airborne transmission. As such, the scientific community sets minimum limits on ventilation with the idea that increased ventilation reduces pathogen concentration and thus reduces the risk of transmission. In contrast, the upper limit on ventilation is usually determined by human comfort and the need to reduce energy consumption. While average pathogen concentration decreases with increased ventilation, local concentration depends on multiple factors and may not follow the same trend, especially within short exposure times over large separation distances. Here, we show through experiments and high-fidelity simulations the existence of a …

Watercave: Virtual Reality For Engaging The Next Generation In Wastewater Management, Leeza Duller

Graduate Student and Postdoctoral Fellow Symposium

Within the next five to ten years, a significant portion of water and wastewater personnel are expected to retire, posing a substantial challenge for the utilities industry. The potential shortage of experienced workers poses inherent risks to the continuity of water services. WaterCAVE emerges as one of several tools designed to address this impending issue by engaging and inspiring the next generation to consider careers in the wastewater industry. This virtual reality (VR) simulation utilizes a ten-sided immersive display and was designed using Unity's 3D real-time development platform. Students from various educational levels, ranging from Pre-K to 12, are invited …

Dyvir: Virtual Reality Generated Synthetic Training Datasets For Ai, Garrett Williams

Graduate Student and Postdoctoral Fellow Symposium

Artificial Intelligence (AI) can perform complex tasks quickly such as object detection. To perform these tasks, the AI algorithms are first trained on data. However, some data such as labeled imagery of aerial objects is hard to obtain. Utilizing Virtual Reality (VR) software, a custom tool called DyViR was made to generate synthetic training datasets. Users customize the virtual environment, aerial objects, and sensor modality to produce custom-tailored datasets.

Use Of Waste Plastics In Asphalt Mixes: Addressing The Variability Of Source, Venkatsushanth Revelli, Anil Kumar Baditha

Graduate Student and Postdoctoral Fellow Symposium

Use of waste plastics in asphalt mixtures suffers from a serious problem of significant variability with global sources; preventing proper guidelines for field applications. The aim of this study is to address the variability in source of waste plastic and its impact on asphalt mixture design. The study was designed to provide a selection criterion to evaluate the suitability of waste polyethylene (PE) for asphalt pavements. PE obtained from five sources was used as a replacement for asphalt binder. Dry mixing of plastics with asphalt and aggregate was performed at the dosage levels of 3%, 6%, and 9%. The changes …

Performance Assessment Of Microencapsulated Phase Change Materials With Low To High Thermoregulation Range In Asphalt Binder, Anil Kumar Baditha, Ayyaz Fareed

Graduate Student and Postdoctoral Fellow Symposium

Asphalt pavements face significant challenges due to low temperature cracking and rutting caused by extreme temperature fluctuations and traffic loading. These issues result in higher maintenance costs and reduced service life of the pavements. To address this, researchers explored the use of Microencapsulated Phase Change Materials (MPCMs) to induce thermoregulation in asphalt pavements. However, the existing research focused on high-temperature performance of binders, highlighting the need of research on evaluating the low-temperature performance. Therefore, the study aims to evaluate the impact of incorporating MPCMs on low to high temperature performance of binders. Three types of MPCMs were incorporated into asphalt …

Circular Economy Eu Networks Inventory, Mark Kelly, James O’Donnell, Derek Sinnott, Azedine Derardja, Sadaf Dalirazar, Ioannis Markou

Tools

Circular Economy EU Networks Inventory is a review of complementary EU research projects in the area of Circular Economy

Development Of 3d Printed Anatomically Equivalent Thermoplastic Polyurethane Conduits For Peripheral Nerve Regeneration, Allen Zennifer M

Theses and Dissertations

Three-dimensional (3D) printing is an emerging tool for creating patient-specific tissue constructs analogous to the native tissue microarchitecture. In this study, anatomically equivalent 3D nerve conduits were developed using thermoplastic polyurethane (TPU) by combining reverse engineering and material extrusion (i.e., fused deposition modelling) technique.

Printing parameters were optimized to fabricate nerve-equivalent TPU constructs. The TPU constructs printed with different infill densities supported the adhesion, proliferation, and gene expression of neuronal cells. Subcutaneous implantation of the TPU constructs for three months in rats showed neovascularization with negligible local tissue inflammatory reactions and was classified as a non-irritant biomaterial as per ISO …

Modeling Studies Of An Intensified Reforming/Fischer-Tropsch Synthesis Process For Gas To Liquid Conversion, Brian Gray

USF Tampa Graduate Theses and Dissertations

Despite rigorous study and advancement in fields of green energy, the world's transportation industry remains poised to continue reliance on liquid hydrocarbon fuels. To date, the primary source of diesel and jet fuels is the petroleum industry; however, continuing trends in rising greenhouse gas emissions present a need for study into processes for the production of synthetic hydrocarbon fuels. The most promising technologies to meet this goal are gas-to-liquid (GtL), biomass-to-liquid (BtL) and coal-to-liquid (CtL). The commonality of these technologies is that they utilize a feedstock to produce carbon monoxide and hydrogen gas (syngas) which becomes the building blocks of …

Routing Problems Through The Lens Of Hybrid Algorithms, Sasan Mahmoudinazlou

USF Tampa Graduate Theses and Dissertations

This dissertation explores novel approaches to address complex combinatorial optimization challenges in transportation and routing scenarios. Three sets of contributions are presented, each encapsulated in a chapter. The first set of contributions introduces a pioneering hybrid genetic algorithm meticulously crafted to address the intricacies of the Traveling Salesman Problem with Drone (TSPD) and the Flying Sidekick Traveling Salesman Problem (FSTSP). These emerging problems involve the strategic use of both ground-based trucks and aerial drones for efficient package delivery. Our algorithm stands out by leveraging sophisticated chromosomes and dynamic programming, allowing for broad exploration by the genetic algorithm and effective exploitation …