Engineering Commons^™

Luminescent Coupling In Perovskite Tandem Solar Cells: The Advantages Of Perovskite And Luminescent Coupling In Photovoltaics, Briana Dokken

Senior Seminars and Capstones

Multijunction or tandem solar cells are made of multiple semiconductor light absorbing layers. Having multiple absorber layers in a solar cell allows it to absorb a larger range of the solar spectrum. When electrons recombine (relax to a lower energy state) in the top layer of a tandem solar cell, they can emit luminescent photons that are absorbed by the bottom layer of the cell. This process is called luminescent coupling, and it can be used to enhance the performance of photovoltaic cells. Another strategy to increase solar cell performance is to use perovskite as the absorber layer material. Currently, …

Strategies To Mitigate Electrostatic Charging During Coffee Grinding, Joshua Méndez Harper, Robin E. Bumbaugh, Christopher H. Hendon

Electrical and Computer Engineering Faculty Publications and Presentations

Summary: Coffee grinding generates electrostatically charged particles, causing clumping, spark discharge, and beyond. When brewing, the particle aggregates affect liquid-solid surface accessibility, leading to variable extraction quality. Here, we study four charge mitigation strategies. De-electrification is readily achieved by adding small amounts of water to whole beans or by bombarding the grounds with ions produced from a high-voltage ionizer. While these techniques helped reduce visible mess, only water inclusion was found to impact coffee extracts prepared as espresso. Wetting whole beans with less than 0.05 mL/g resulted in a marked shift in particle size distribution, by preventing clump formation and …

Evaluating Fine Tuned Deep Learning Models For Real-Time Earthquake Damage Assessment With Drone-Based Images, Furkan Kizilay, Mina R. Narman, Hwapyeong Song, Husnu S. Narman, Cumhur Cosgun, Ammar Alzarrad

Computer Sciences and Electrical Engineering Faculty Research

Earthquakes pose a significant threat to life and property worldwide. Rapid and accurate assessment of earthquake damage is crucial for effective disaster response efforts. This study investigates the feasibility of employing deep learning models for damage detection using drone imagery. We explore the adaptation of models like VGG16 for object detection through transfer learning and compare their performance to established object detection architectures like YOLOv8 (You Only Look Once) and Detectron2. Our evaluation, based on various metrics including mAP, mAP50, and recall, demonstrates the superior performance of YOLOv8 in detecting damaged buildings within drone imagery, particularly for cases with moderate …

Precision Medicine For Apical Lesions And Peri-Endo Combined Lesions Based On Transfer Learning Using Periapical Radiographs, Pei Yi Wu, Yi Cheng Mao, Yuan Jin Lin, Xin Hua Li, Li Tzu Ku, Kuo Chen Li, Chiung An Chen, Tsung Yi Chen, Shih Lun Chen, Wei Chen Tu, Patricia Angela R. Abu

Ateneo Laboratory for Intelligent Visual Environments

An apical lesion is caused by bacteria invading the tooth apex through caries. Periodontal disease is caused by plaque accumulation. Peri-endo combined lesions include both diseases and significantly affect dental prognosis. The lack of clear symptoms in the early stages of onset makes diagnosis challenging, and delayed treatment can lead to the spread of symptoms. Early infection detection is crucial for preventing complications. PAs used as the database were provided by Chang Gung Memorial Medical Center, Taoyuan, Taiwan, with permission from the Institutional Review Board (IRB): 02002030B0. The tooth apex image enhancement method is a new technology in PA detection. …

Transfer Learning With Spinally Shared Layers, H. M.Dipu Kabir, Subrota Kumar Mondal, Syed Bahauddin Alam, U. Rajendra Acharya

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Transfer-learned models have achieved promising performance in numerous fields. However, high-performing transfer-learned models contain a large number of parameters. In this paper, we propose a transfer learning approach with parameter reduction and potential high performance. Although the high performance depends on the nature of the dataset, we ensure the parameter reduction. In the proposed SpinalNet shared parameters, all intermediate-split-incoming parameters except the first-intermediate-split contain a shared value. Therefore, the SpinalNet shared parameters network contains three parameter groups: (1) first input-split to intermediate-split parameters, (2) shared intermediate-split-incoming parameters, and (3) intermediate-split-to-output-split parameters. The total number of parameters becomes lower than the …

Self-Replication Via Tile Self-Assembly, Andrew Alseth, Daniel Hader, Matthew J. Patitz

Computer Science and Computer Engineering Faculty Publications and Presentations

In this paper we present a model containing modifications to the Signal-passing Tile Assembly Model (STAM), a tile-based self-assembly model whose tiles are capable of activating and deactivating glues based on the binding of other glues. These modifications consist of an extension to 3D, the ability of tiles to form “flexible” bonds that allow bound tiles to rotate relative to each other, and allowing tiles of multiple shapes within the same system. We call this new model the STAM*, and we present a series of constructions within it that are capable of self-replicating behavior. Namely, the input seed assemblies to …

Evaluating Mixed Reality Technology For Tracking Hand Motion For Shoulder Rehabilitation Assessment*, Sergio A. Salinas, Katarina Grolinger, Marie-Eve Lebel, Ana Luisa Trejos

Electrical and Computer Engineering Publications

Shoulder injuries and conditions are common musculoskeletal complaints that can limit a patient’s range of motion and daily activities. Recently, serious games and mixed reality technologies, such as the HoloLens, have been proposed for shoulder rehabilitation. However, it is unclear if this technology accurately tracks 3D hand movementsfor reporting therapy-related kinematic metrics. This paper presents accuracy and repeatability tests of the HoloLens 2 in tracking hand movements, and its potential for shoulder rehabilitation assessment. Comparisons were made between index fingertip, palm, and wrist movements captured by the HoloLens 2 and an Aurora electromagnetic system, which was used as the ground …

Improving The Cooling Time Of Twisted Coiled Actuators In Soft Robotics, Alex Lizotte, Parisa Daemi, Brendan Difabio, Ana Luisa Trejos

Electrical and Computer Engineering Publications

Fabric cooling channels for twisted coiled actuators (TCAs) were recently proposed to achieve the required response times for motion assistance in a manner suitable for soft wearable robotic devices. While previous work demonstratedthat the fabric channel reduced the cooling time by 42% in comparison to the same TCA without the cooling channel, the TCAs were still not cooled quickly enough to support human motion. Therefore, in this paper, two variations to the channel are proposed to further reduce the cooling time of the TCAs. The variations include unsealing the inlet and adding vents along the length of the channel to …

Further Evaluations Of A Didactic Cpu Visual Simulator (Cpuvsim), Renato Cortinovis, Tamer Mohamed Abdellatif, Devender Goyal, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

This paper discusses further evaluations of the educational effectiveness of an existing CPU visual simulator (CPUVSIM). The CPUVSIM, as an Open Educational Resource, has been iteratively improved over a number of years following an Open Pedagogy approach, and was designed to enhance novices’ understanding of computer operation and mapping from high-level code to assembly language. The literature reports previous evaluations of the simulator, at K12 and undergraduate level, conducted from the perspectives of both developers and students, albeit with a limited sample size and primarily through qualitative methods. This paper describes additional evaluation activities designed to provide a more comprehensive …

2024 Safety Belt Usage Survey In Kentucky, Erin Lammers-Staats, Derek Young, Kenneth R. Agent

Kentucky Transportation Center Research Report

No abstract provided.

Experimental Study Of Drag Characteristics And Dust Removal Performance Of A Hybrid Wet-Filter Precipitator, Hang Yi, Zifeng Yang, Deqiang Chang, Xinjiao Tian, Jingxian Liu

Mechanical and Materials Engineering Faculty Publications

With their advantages of high dust removal efficiency and low drag characteristics, hybrid wet-filter precipitators have great potential for dust control in coal mines, but the underlying mechanisms are not well understood. In this study, to help fill this knowledge gap, a hybrid wet-filter precipitator consisting of a 40-layer metal filter and a defogger device is designed and a prototype is constructed. Experiments are conducted to investigate its drag characteristics under wind velocities from 0.85 to 5.68 m/s and its dust removal performance under wind velocities of 2 and 4 m/s. On the basis of results with the initial design, …

256-Level Honey Memristor-Based In-Memory Neuromorphic System, Harshvardhan Uppaluru, Zoe Templin, Mohammed Rafeeq Khan, Md Omar Faruque, Feng Zhao, Jinhui Wang

Electrical and Computer Engineering Faculty Research & Creative Works

Promising synaptic behavior has been exhibited by memristors based on natural organic materials. Such memristor-based neuromorphic systems offer notable benefits, including environmental sustainability, low production and disposal costs, non-volatile storage capability, and bio/Complementary Metal-Oxide-Semiconductor (CMOS) compatibility. Here, a 256-level honey memristor-based neuromorphic system is experimentally evaluated for image recognition. In detail, first, 256-level honey memristors are manufactured and tested based on in-house technology; next, the non-linear characteristics and inherent variation of honey memristor devices, which lead to imprecise weight updates and limit the inference accuracy, are investigated. Experimental results indicate that the inference accuracy of the 256-level honey memristor-based neuromorphic …

A New Air-Assisted Flare Tip Design For Managing Gas Flare Emissions (Cfd Analysis), Ahmed A. Maaroof, Joseph D. Smith, Mohammed H.S. Zangana

Chemical and Biochemical Engineering Faculty Research & Creative Works

Recently, flares have been considered as a major source of air pollution from the petroleum refining industry. The United Nations has instigated an international effort related to the management of flare emissions to reduce the global warming impact related to flaring. Eliminating or removing the need for gas flares is difficult because these devices are generally used as safety devices to allow the combustion of flammable gases in a controlled fashion which supports safe operation. However, reducing flaring is generally possible using well-designed, efficiently operated flare equipment. In general, flare performance can be enhanced following the API-521 methodology and using …

Investigating A Pollinator Curriculum (1-3 Grade), Divya Baranwal

Multidisciplinary Studies Research

In this unit, elementary graders will identify and explain the pollen, flowering plants, and pollination process, and labelled various parts of a flower, pollinators. They will build the model of pollinators, initial models of the reproductive parts of plants. They will explore the 3D shapes, magnifying glasses, area and volume, modelling and explain low-high fidelity prototyping, engineering design process. The unit is designed by providing an abundance of practical ways to learn the significance of the pollination process and to get to know about pollinators and pollen in a place-based environment. Here, students will engage, explore, explain, elaborate and evaluate …

Spot, Zone And Overcoat Painting Of Steel Bridges, Christopher Goff, Sudhir Palle

Kentucky Transportation Center Research Report

Over the past 25 – 30 years, the Kentucky Transportation Cabinet (KYTC) has replaced lead-based coatings on many bridges, often with zinc-based systems. But many of these coating systems are now degrading and reaching the ends of their service lives. Historically, KYTC has relied entirely on remove-and-replace painting, however, given the programmatic costs associated with remove-and-replace painting and constraints imposed by limited funding, the agency needs to explore more economical options, such as spot, zone, and overcoat painting. This report discusses use cases for spot, zone, and overcoat painting and lays out guidelines staff can use to determine what method …

First-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Neural Ordinary Differential Equations: Mathematical Framework And Illustrative Application To The Nordheim–Fuchs Reactor Safety Model, Dan Gabriel Cacuci

Faculty Publications

This work introduces the mathematical framework of the novel “First-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Neural Ordinary Differential Equations” (1st-CASAM-NODE) which yields exact expressions for the first-order sensitivities of NODE decoder responses to the NODE parameters, including encoder initial conditions, while enabling the most efficient computation of these sensitivities. The application of the 1st-CASAM-NODE is illustrated by using the Nordheim–Fuchs reactor dynamics/safety phenomenological model, which is representative of physical systems that would be modeled by NODE while admitting exact analytical solutions for all quantities of interest (hidden states, decoder outputs, sensitivities with respect to all parameters and initial conditions, …

Electromagnetic Theory And Applications, 2nd Edition, Nicholas Madamopoulos, George Kliros

Open Educational Resources

This book intends to provide both the fundamentals of Electromagnetics but also some practical applications of the concepts covered. Having taught electromagnetics for several years, the authors feel that many times the field of electromagnetics comes as “old” and often times students do not appreciate the concepts and their importance in everyday applications. The authors intend to accompany the EM concepts with life applications. Hence, students may see the direct impact of the knowledge they acquire through the study of the field of electromagnetics and better appreciate the field.

Design And Analysis Of Self-Tanked Stepwise Charging Circuit For Four-Phase Adiabatic Logic, William Morell, Jin Woo Choi

Michigan Tech Publications

Adiabatic logic has been proposed as a method for drastically reducing power consumption in specialized low-power circuits. They often require specialized clock drivers that also function as the main power supply, in contrast to standard CMOS logic, and these power clocks are often a point of difficulty in the design process. A novel, stepwise charging driver circuit for four-phase adiabatic logic is proposed and validated through a simulation study. The proposed circuit consists of two identical driver circuits each driving two opposite adiabatic logic phases. Its performance relative to ideal step-charging and a standard CMOS across mismatched phase loads is …

First-Principles Simulation Of The Interaction Between Dna Nucleotides And One-Dimensional Carbon Chain In Electrical Based Sequencing, Zeina Salman, Jin-Woo Kim, Steve Tung

Biological and Agricultural Engineering Faculty Publications and Presentations

Electrical DNA sequencing has attracted significant attention in recent years due to its simplified sequencing protocol, compact sequencing system, and relatively low sequencing cost. In the design and fabrication of the sequencing device, carbon-based nanomaterials such as graphene have been explored as a promising sensing material that provides an excellent combination of spatial resolution and base specificity. Using first-principles simulation, we determined the effect on the electrical conductivity of a one-dimensional carbon chain due to the presence of four DNA bases. The simulation results indicate that the interaction between the carbon chain and different DNA bases leads to different levels …

Study Of The Structure Of Zn And Na Borophosphate Glasses Using X-Ray And Neutron Scattering Techniques, Uwe Hoppe, Parker T. Freudenberger, Richard K. Brow, Jozef Bednarčik, Alex C. Hannon

Materials Science and Engineering Faculty Research & Creative Works

The atomic structures of Zn and Na borophosphate glasses were studied using X-ray and neutron scattering techniques. Peaks assigned to the B−O, P−O, and O−O distances confirm that only BO₄ units co-exist with the PO₄ tetrahedra. The Zn−O and Na−O coordination numbers are found to be a little larger than four. The narrowest peaks of the Zn−O first-neighbor distances exist for the glasses along a line connecting the Zn (PO₃)₂ and BPO₄ compositions (50 mol% P₂O₅), which is explained by networks of ZnO₄, BO₄, and PO …

Ground Vacuum Facility To Simulate Low Earth Orbit Plasma Environment, Emmanuel Kofi Asuako Wie-Addo, Jacob Ortega, Daoru Han

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents a large vacuum facility (6-ft-diameter, 10-ft-long chamber) equipped with a magnetic filter-type low Earth orbit plasma source. A recommended operating envelope for the plasma source was established through single-point measurements by varying the discharge currents of the plasma source and the gas flow rates. A three-axis translation stage was fabricated and tested with 2D and 3D scans of the simulated plasma environment. The measured plasma density during this study was between 1:63 x 1012 − 3:1 x 1012 m−3 for the electrons and 7:54 x 1012 − 1:82 x 1013 m−3 for the ions, whereas the electron …

Asphalt-Binder Mixtures Evaluated By T1 Nmr Relaxometry, Rebecca M. Herndon, Jay Balasubramanian, Magdy Abdelrahman, Klaus Woelk

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt pavements make up a majority of the essential transportation systems in the US. Asphalt mixtures age and degrade over time, reducing the pavement performance. Pavement performance critically depends on the aging of asphalt binder. the aging of asphalt binder during construction is traditionally modeled by rolling thin film oven (RTFO) testing, while aging during service life is modeled by pressure aging vessel (PAV) testing. Comparing these models to the aging of binders in actual pavements is limited because, to be used for current testing, binders must be separated from the pavement's aggregate by solvent extraction. Solvent extraction will, at …

Analysis Of The Thermal Aging Kinetics Of Tallow, Chicken Oil, Lard, And Sheep Oil, Yun-Chuan Hsieh, Hao Ouyang, Yulin Zhang, Donyau Chiang, Fuqian Yang, Hsin-Lung Chen, Sanboh Lee

Chemical and Materials Engineering Faculty Publications

Understanding the thermal aging kinetics of animal oils is of vital importance in the storage and applications of animal oils. In this work, we use four different techniques, including UV-Vis spectrometry, viscometry, impedance spectroscopy, and acid–base titration, to study the thermal aging kinetics of tallow, chicken oil, lard, and sheep oil in the temperature range from 120 ◦C to 180 ◦C. The evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration are discussed with the defect kinetics. The evolutions of the color centers, defects for dynamic viscosity, and electric dipoles follow second-order, first-order, and zero-order kinetics, respectively. …

Behind Armor Blunt Trauma: Liver Injuries Using A Live Animal Model, Narayan Yoganandan, Alok Shah, Brian D. Stemper, Lewis Somber, Valeta Carol Chancey, Joseph Mcentire

Biomedical Engineering Faculty Research and Publications

Introduction

While the 44-mm clay penetration criterion was developed in the 1970s for soft body armor applications, and the researchers acknowledged the need to conduct additional tests, the same behind the armor blunt trauma displacement limit is used for both soft and hard body armor evaluations and design considerations. Because the human thoraco-abdominal contents are heterogeneous, have different skeletal coverage, and have different functional requirements, the same level of penetration limit does not imply the same level of protection. It is important to determine the regional responses of different thoraco-abdominal organs to better describe human tolerance and improve the current …

High-Mast Tower Foundation – Phase Ii, Ammar Al Maabreh, Abdelrahman Awawdeh, Marc Maguire, Jay Puckett, Brandon Kreiling

Nebraska Department of Transportation: Research Reports

Challenge: High-mast luminaire supports used in the US transportation sector are typically steel poles that are attached to a baseplate via a butt or socket weld. Many have failed primarily due to fatigue cracking at the weld toe. Significant research in the US improved the fatigue performance of these structures; however, failures still occur due to high-cycle cracking at the weld toes, or at other fatigue-prone details. Additionally, poles are failing in moderate winds that create galloping. Galloping is an aerodynamic phenomenon where the wind excitation frequency matches the pole’s natural frequency creating resonance. The top amplitudes are many times …

2024 Summer Proceedings Teuscher Lab, Teuscher Group, Christof Teuscher, Chelsea Ogbede, Lauren Sanday, Sofia Vargas, Artem Arefev

altREU Projects

How will computation evolve in the coming years? What problems can be tackled using artificial intelligence, in a world increasingly driven by data? And how can that data be used to better inform our decisions as a society? In this unique collection of research projects, each chapter represents a distinct work undertaken by a single individual or a group of students as part of the altREU program led by Christof Teuscher. The projects, rooted in applications of artificial intelligence and innovative computation techniques, examine impactful solutions to numerous pressing challenges affecting communities around the world.

Reducing Attack Opportunities Through Decentralized Event-Triggered Control, Paul Griffioen, Raffaele Romagnoli, Bruce H. Krogh, Bruno Sinopoli

Faculty Work Comprehensive List

Cyber-physical systems are prevalent in many critical infrastructures and are vulnerable to a variety of attacks from the network. Decentralized control systems are particularly vulnerable since they rely heavily on network communication to achieve their goals. To address network vulnerabilities, we present an event-triggered network connection and communication protocol that minimizes the amount of time agents are connected to the network, reducing the window of opportunity for attacks. This mechanism is a function of only local information and ensures stability for the overall system in attack-free scenarios. Our approach distinguishes itself from current decentralized event-triggered control strategies by considering an …

Growth And Faceting Of Tungsten And Oxides In Scandate Cathode Particles During In Situ Heating In The Scanning Electron Microscope, Huanhuan Bai, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Tungsten-based scandate dispenser cathodes are promising next-generation thermionic electron sources for vacuum electron devices, due to their excellent emission performance at tempera- tures lower than those required for conventional cathodes. There has been a significant recent effort to understand scandate cathode performance and to characterize the tungsten and other materials on the emitting surface, primarily via the study of cathodes before and after emission testing. Moreover, these scandate cathodes have typically been characterized at room temperature only. In situ obser- vations of scandate cathodes is challenging, as these devices are thermionic emitters that operate in a high-vacuum environment, and because …

Effects Of External Pressure On Cycling Performance Of Silicon-Based Lithium-Ion Battery: Modelling And Experimental Validation, Kai Zhang, Yinan He, Junwu Zhou, Xinyang Wang, Yong Li, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Controlling the stress state of electrodes during electrochemical cycling can have a positive effect on the cycling performance of lithium-ion battery. In this work, we study the cycling performance of silicon-based lithium-ion half cells under the action of pressure in a range of 0.1 to 0.4 MPa. The cycling performance of the silicon-based lithium-ion half cells increases first with increasing the pressure to 0.2 MPa and then decreases with further increasing the pressure. The analysis of the surface morphologies of cycled electrodes reveals that applying a pressure of 0.2 MPa leads to the formation of fine electrode surface with the …

Response Of ¹¹B Enriched Zrb2 Ultra-High Temperature Ceramic To Neutron Irradiation At Elevated Temperatures, Yan Ru Lin, Takaaki Koyanagi, David J. Sprouster, Christian M. Petrie, William Fahrenholtz, Greg Hilmas, Yutai Katoh

Materials Science and Engineering Faculty Research & Creative Works

ZrB₂, an ultra-high temperature ceramic (UHTC) is being considered for use in fusion reactor first-wall structures, yet its response to irradiation remains poorly understood. This study employed scanning/transmission electron microscopy (S/TEM), synchrotron X-ray diffraction (XRD), finite element calculations, and thermal property measurements to thoroughly investigate the neutron-irradiation effects on ¹¹B-enriched ZrB₂. Neutron irradiations were conducted at 220 °C and 620 °C, with a neutron fluence of 2.2 x 1025 neutron/m2 (energy > 0.1 MeV), resulting in 3.9 dpa and 4200 appm He. The study revealed the unusual prevalence of prism loops and a > c anisotropic lattice …