Engineering Commons^™

Quantum & Classical Machine Learning Studies Of Semiconductor Crystal Epitaxy, Andrew S. Messecar, Steven M. Durbin, Robert A. Makin

Waldo Library Student Exhibits

Molecular beam epitaxy (MBE) is an ultra–high vacuum crystal growth technique for the synthesis of high–purity materials. MBE allows for controlled deposition to the precision of a single atomic layer.

Understanding the optimal synthesis conditions for MBE can enhance experiment design and accelerate the discovery of new materials.

In this study, we apply materials informatics – investigating the utility of both quantum and conventional machine learning algorithms – to a decade’s worth of plasma–assisted MBE (PAMBE) data of GaN and InN. The goal is to investigate the relationships between PAMBE growth conditions and figures of merit for semiconductor crystals.

Air Force Institute Of Technology Research Report 2022, Air Force Institute Of Technology

AFIT Documents

This report summarizes the research activities of the Air Force Institute of Technology's Graduate School of Engineering and Management, as well as AFIT's research centers. It describes research interests and faculty expertise; list student theses/dissertations; identifies research sponsors and contributions; and outlines the procedure for contacting entities within the Institution.

Air Force Institute Of Technology Research Report 2021, Air Force Institute Of Technology

AFIT Documents

This report summarizes the research activities of the Air Force Institute of Technology's Graduate School of Engineering and Management, as well as AFIT's research centers. It describes research interests and faculty expertise; list student theses/dissertations; identifies research sponsors and contributions; and outlines the procedure for contacting entities within the Institution.

Auxiliary Diagnosis Of Dental Calculus Based On Deep Learning And Image Enhancement By Bitewing Radiographs, Tai Jung Lin, Yen Ting Lin, Yuan Jin Lin, Ai Yun Tseng, Chien Yu Lin, Li Ting Lo, Tsung Yi Chen, Shih Lun Chen, Chiung An Chen, Kuo Chen Li, Patricia Angela R. Abu

Ateneo Laboratory for Intelligent Visual Environments

In the field of dentistry, the presence of dental calculus is a commonly encountered issue. If not addressed promptly, it has the potential to lead to gum inflammation and eventual tooth loss. Bitewing (BW) images play a crucial role by providing a comprehensive visual representation of the tooth structure, allowing dentists to examine hard-to-reach areas with precision during clinical assessments. This visual aid significantly aids in the early detection of calculus, facilitating timely interventions and improving overall outcomes for patients. This study introduces a system designed for the detection of dental calculus in BW images, leveraging the power of YOLOv8 …

Learning From Oversampling: A Systematic Exploitation Of Oversampling To Address Data Scarcity Issues In Deep Learning- Based Magnetic Resonance Image Reconstruction, Ibsa Kumara Jalata, Reeshad Khan, Ukash Nakarmi

Computer Science and Computer Engineering Faculty Publications and Presentations

Data acquisitions in Magnetic Resonance Imaging (MRI) are inherently slow due to sequential acquisition protocol. Image reconstruction from under-sampled data is posed as an inverse problem in traditional model-based learning paradigms. Recent data-centric learning frameworks such as deep learning (DL) frameworks are data hungry, and demand a large, labeled training data sets. To address the lack of large training datasets, in MRI reconstructions, researchers approach the problem in two ways: (1) unsupervised method where the model is trained without the presence of fully sampled data. (2) using a method that efficiently use the limited dataset for training purpose. In this …

Energy And Environmental Analyses Of A Solar–Gas Turbine Combined Cycle With Inlet Air Cooling, Ahmad M. Abubaker, Adnan Darwish Ahmad, Binit B. Singh, Yaman M. Manaserh, Loiy Al-Ghussain

Institute of Research for Technology Development Faculty Publications

Sensitivity to ambient air temperatures, consuming a large amount of fuel, and wasting a significant amount of heat dumped into the ambient atmosphere are three major challenges facing gas turbine power plants. This study was conducted to simultaneously solve all three aforementioned GT problems using solar energy and introducing a new configuration that consists of solar preheating and inlet-air-cooling systems. In this study, air was preheated at a combustion chamber inlet using parabolic trough collectors. Then, inlet air to the compressor was cooled by these collectors by operating an absorption cooling cycle. At the design point conditions, this novel proposed …

Experimental Study On The Detection Of The Existence And Location Of Mimicked And Unexpected Interface Debonding Defects In An Existing Rectangular Cfst Column With Pzt Materials, Qian Liu, Bin Xu, Genda Chen, Weilong Ni, Zhixun Liu, Chun Lin, Zhiyou Zhuang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Interface bonding conditions between concrete and steel materials play key roles in ensuring the composite effect and load-carrying capacity of concrete–steel composite structures such as concrete-filled steel tube (CFST) members in practice. A method using both surface wave and electromechanical impedance (EMI) measurement for detecting the existence and the location of inaccessible interface debonding defects between the concrete core and steel tube in CFST members using piezoelectric lead zirconate titanate (PZT) patches as actuators and sensors is proposed. A rectangular CFST specimen with two artificially mimicked interface debonding defects was experimentally verified using PZT patches as the actuator and sensor. …

The Impacts Of Dimensionality, Diffusion, And Directedness On Intrinsic Cross-Model Simulation In Tile-Based Self-Assembly, Daniel Hader, Matthew J. Patitz

Computer Science and Computer Engineering Faculty Publications and Presentations

Motivated by applications in DNA-nanotechnology, theoretical investigations in algorithmic tile-assembly have blossomed into a mature theory. In addition to computational universality, the abstract Tile Assembly Model (aTAM) was shown to be intrinsically universal (FOCS 2012), a strong notion of completeness where a single tile set is capable of simulating the full dynamics of all systems within the model; however, this construction fundamentally required non-deterministic tile attachments. This was confirmed necessary when it was shown that the class of directed aTAM systems, those where all possible sequences of tile attachments result in the same terminal assembly, is not intrinsically universal (FOCS …

Form Pressure Exerted By Concrete For A Large-Scale Structure: Its Quantification And Physicochemical Interpretation, Tae Yong Shin, Seongho Han, Jin Hyun Lee, Jae Hong Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Securing safety in formwork is one of the most important tasks to be carried out in the initial stage of construction. The form pressure exerted by fresh concrete needs to be identified, and it should be retained by a formwork system. A design pressure is given in literature and standards, but for large structures its precise prediction is required through a detailed analysis or a mock-up test. This study reports the lateral form pressure distribution generated by fresh concrete through a series of mock-up tests. The tests are designed considering the placement for nuclear containment structures; 3.4 m tall and …

Tribocorrosion And Metal Release From Austenitic Stainless Steels 304 And 201 In Simulated Cassava Food Contact, Robert Addai, Temitope E. Olowoyo, Thalia E. Standish, Jeffrey Daniel Henderson, Ubong Eduok, Yolanda Hedberg

Chemistry Publications

Cassava is the third most significant calorie source in the tropics. Its processing has changed from traditional methods to stainless steel processing machines. This study investigated the influence of cassava on metal release from two common stainless steels, ASTM 304 and 201, with and without friction, and on tribocorrosion (multianalytically) of 304. Cassava was relatively corrosive and hindered repassivation of the surface oxide of stainless steel, but it also acted as a lubricant against mechanical friction. The combined action of friction and cassava caused a significant increase in iron, chromium, nickel, and manganese release from the stainless steels (30–35- fold …

Solar Car Radio Control Car Curriculum (9-10 Grade), Divya Baranwal, Ashish Gandhi

Multidisciplinary Studies Research

In this unit, high school students will comprehend the concepts of solar energy and conversion of sunlight into electricity; and basic electronics, circuitry principles, and electric components like microcontrollers, resistors, sensors, and LEDs; basic programming hands-on experience to write code for microcontrollers and programming functionalities like controlling the car’s movement, and the conversion of potential energy to kinetic energy on various inclined ramps, delving into scientific principles. They will understand the basics of machine learning, robotics, soldering, engage with hands-on experiences in engineering design principles, hands-on experiences starting from building car evolution models throughout a week. This unit focus to …

Carbon-Based Nanocomposite Membranes For Membrane Distillation: Progress, Problems And Future Prospects, Chhabilal Regmi, Yuwaraj K. Kshetri, S. Ranil Wickramasinghe

Chemical Engineering Faculty Publications and Presentations

The development of an ideal membrane for membrane distillation (MD) is of the utmost importance. Enhancing the efficiency of MD by adding nanoparticles to or onto a membrane’s surface has drawn considerable attention from the scientific community. It is crucial to thoroughly examine state-of-the-art nanomaterials-enabled MD membranes with desirable properties, as they greatly enhance the efficiency and reliability of the MD process. This, in turn, opens up opportunities for achieving a sustainable water–energy–environment nexus. By introducing carbon-based nanomaterials into the membrane’s structure, the membrane gains excellent separation abilities, resistance to various feed waters, and a longer lifespan. Additionally, the use …

Effects Of Wall And Freespace Damping Levels On Virtual Wall Stiffness Classification, Emma Treadway, Kristian Journet, Andrew Deering, Cora Lewis, Noelle Poqiz

Engineering Faculty Research

Virtual damping is often employed to improve stability in virtual environments, but it has previously been found to bias perception of stiffness, with its effects differing when it is introduced locally within a wall/object or globally in both the wall and in freespace. Since many potential applications of haptic rendering involve not only comparisons between two environments, but also the ability to recognize rendered environments as belonging to different categories, it is important to understand the perceptual impacts of freespace and wall damping on stiffness classification ability. This study explores the effects of varying levels of freespace and wall damping …

Performance And Environmental Assessment Of Biochar-Based Membranes Synthesized From Traditional And Eco-Friendly Solvents, Abelline Katusiime Fionah, Isaac Oluk, Laura Brady, Diana M. Byrne, Isabel Escobar

UK CARES Faculty Publications

Water contamination resulting from coal spills is one of the largest environmental problems affecting communities in the Appalachia Region of the United States. This coal slurry contains potentially toxic substances, such as hydrocarbons, heavy metals, and coal cleaning chemicals, and its leakage into water bodies (lakes, rivers, and aquifers) can lead to adverse health effects not only for freshwater bodies and plant life but also for humans. This study focused on two major experiments. The first experiment involved the use of biochar to create a biochar–polysulfone (BC-PSf) flat-sheet multifunctional membrane to remove organic contaminants, and the other major experiment compared …

Synergetic Effect Of Viscosity Modifying Admixtures And Polycarboxylate Ether Superplasticizer On Key Characteristics Of Thixotropic Uhpc For Bonded Bridge Deck Overlay Rehabilitation, Le Teng, Ming Jin, Jiadi Du, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Thin bonded ultra-high-performance concrete (UHPC) overlay is an advanced technology for bridge deck rehabilitation. UHPC should be tailored to secure adequate flowability and high thixotropy to facilitate mixing and placement with a low risk of sagging of the material on sloped bridge deck surfaces. The synergetic effect between nano clay (NC) and polycarboxylate ether (PCE) superplasticizer or cellulose-based viscosity modifying admixture (VMA) and PCE on the rheological properties (yield stress, plastic viscosity, and thixotropy), cement hydration, autogenous shrinkage, compressive strength, and porosity was systematically investigated. The bond strength between conventional concrete (CC) representing existing bridge deck concrete and thixotropic UHPC …

Examining The Progress In Additive Manufacturing In Supporting Lean, Green And Sustainable Manufacturing: A Systematic Review, Catherine Maware, Rumbidzai Muvunzi, Tinotenda Machingura, Ilesanmi Daniyan

Institute for Sustainable Manufacturing Faculty Publications

The quest for waste reduction and the development of manufacturing processes that meet the economic, social and environmental requirements necessitate this study. Additive manufacturing is an emerging digital technology that can be used to seamlessly develop a product through material deposition in layers. The study aims to investigate the progress made in the development of additive manufacturing to support lean, green and sustainable manufacturing. The study employs a systematic literature review approach, specifically the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). A total of 158 articles identified from different academic databases that detailed empirical, conceptual and theoretical findings …

In Situ Synthesis, Characterization And Photocatalytic Efficacy Of Silver-Enhanced Mxene And Graphene Nanocomposites, Kishore Chand, M. Mustafa Azeem, Muhammad Nazim Lakhan, Mukhtiar Ahmed, Muhammad Jehanzaib Aslam, Ahmer Hussain Shah

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The emergence of 2D materials has significantly expanded the wide range of nanomaterials with diverse applications. Notably, their high conductivity, catalytic efficiency, and hydrophobicity have fueled heightened research interests for water treatment applications. This research aimed to investigate the synthesis and characterization of MXene and reduced graphene oxide (rGO) nanocomposites with silver nanoparticles (Ag) for enhanced catalytic activity in the decomposition of Direct Blue-24 dye. In this study, we employed well-established methods, previously documented in the literature, to prepare two distinct nanocomposites. Novel nanocomposites, namely reduced graphene oxide–silver nanoparticles (rGO–Ag) and MXene–silver nanoparticles (MXene–Ag), were synthesized using the hydrothermal and …

Pulsing-Induced Healing Of A Surface Crack Of A Nickel-Based Alloy, Liwei Wang, Mingming Quan, Zhen Tan, Ming Liu, Dianlong Wang, Xiao Yang, Ying Liu, Yaning Mao, Zhimin Liang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

In this work, we demonstrate the feasibility of applying electric pulses to heal surface cracks on nickel-based alloy GH4169 under compressive load. There exists an incubation time for the onset of the healing of a crack, which is associated with local temperature at the crack tip. The crack size decreases with increasing the pulsing time at a constant healing rate prior to complete healing of the crack. Increasing compressive load accelerates the healing process. The electric pulsing leads to the formation of an influential zone surrounding the crack with the finest grain sizes in the healed crack and the coarsest …

Developing A Cross-Asset Allocation Mechanism, Jon Wilcoxson, Bryan Gibson, Bethany Paris

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) has developed several tools and methods to compare the value of proposed projects within specific programs and asset classes, including the Enhanced Bridge Prioritization Index, Enhanced Pavement Prioritization Index, and the Strategic Highway Investment Formula for Tomorrow (SHIFT). Although immensely valuable, these methods and tools do not offer a convenient way of comparing the contributions of individual projects to meeting overall KYTC performance goals. As such, the Cabinet needs a robust mechanism for comparing the impact of projects across its capital, safety, and asset management programs. Following a review of cross-asset allocation frameworks described in …

New Method To Calculate Friction Velocity In Smooth Channel Flows Using Direct Numerical Simulation Data, Harshit Mishra, S. Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, we leverage the direct numerical simulation (DNS) data for closed-channel flow for a range of friction Reynolds number (Reτ∼180-5,000) to develop a new one-point friction velocity method (OPFVM) to calculate friction velocity U∗ in terms of free-surface velocity Um, flow depth h, and kinematic viscosity ν. In contrast to prevalent methods that require several cumbersome near boundary measurements to obtain friction velocity, the OPFVM relies on a single easy-to-measure free-surface velocity measurement. The formulation is used to obtain friction velocity for a closed-channel flow (CCF) DNS regime with Reτ=10,049 and on four open-channel flow (OCF) DNS regimes …

React: Recognize Every Action Everywhere All At Once, Naga Venkata Sai Raviteja Chappa, Pha Nguyen, Page Daniel Dobbs, Khoa Luu

Electrical Engineering and Computer Science Faculty Publications and Presentations

In the realm of computer vision, Group Activity Recognition (GAR) plays a vital role, finding applications in sports video analysis, surveillance, and social scene understanding. This paper introduces Recognize Every Action Everywhere All At Once (REACT), a novel architecture designed to model complex contextual relationships within videos. REACT leverages advanced transformer-based models for encoding intricate contextual relationships, enhancing understanding of group dynamics. Integrated Vision-Language Encoding facilitates efficient capture of spatiotemporal interactions and multi-modal information, enabling comprehensive scene understanding. The model’s precise action localization refines joint understanding of text and video data, enabling precise bounding box retrieval and …

Fine-Grained Passenger Load Prediction Inside Metro Network Via Smart Card Data, Xiancai Tian, Chen Zhang, Baihua Zheng

Research Collection School Of Computing and Information Systems

Metro system serves as the backbone for urban public transportation. Accurate passenger load prediction for the metro system plays a crucial role in metro service quality improvement, such as helping operators schedule train timetables and passengers plan their trips. However, existing works can only predict low-grained passenger flows of origin-destination (O-D) paths or inflows/outflows of each station but cannot predict passenger load distribution over the whole metro network. To this end, this paper proposes an end-to-end inference framework, PIPE, for passenger load prediction of every metro segment between two adjacent stations, by only utilizing smart card data. In particular, PIPE …

Microstructural Evolution In A Precipitate-Hardened (Fe0.3ni0.3mn0.3cr0.1)94ti2al4 Multi-Principal Element Alloy During High-Pressure Torsion, Matthew Luebbe, Jiaqi Duan, Peipei Cao, Zhaoping Lu, Rinat K. Islamgaliev, Ruslan Z. Valiev, Yuzi Liu, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Multi-principal element alloys demonstrate high strength, thermal stability, and irradiation resistance, making them excellent candidate materials for applications in nuclear reactors and other harsh environments. Some studies have examined the use of high-pressure torsion to strengthen MPEAs through grain size reduction and strain hardening. However, no studies have investigated the effect of HPT on secondary phases (precipitates) within an MPEA. Two alloys, (Fe_0.3Ni_0.3Mn_0.3Cr_0.1)₉₄Ti₂Al₄ containing Ni(Ti, Al) B2 phase, and CrFe σ phase, and single-phase Fe_0.3Ni_0.3Mn_0.3Cr_0.1, were fabricated by casting …

Optical Frequency Domain Reflectometry-Based High-Performance Distributed Sensing Empowered By A Data And Physics-Driven Neural Network, Zhaopeng Zhang, Wei Peng, Osamah Alsalman, Lingmei Ma, Jie Huang, Chen Zhu

Electrical and Computer Engineering Faculty Research & Creative Works

Optical frequency domain reflectometry (OFDR) based distributed strain sensors are the preferred choice for achieving accurate strain measurements over extensive sensing ranges while maintaining exceptional spatial resolution. However, the simultaneous realization of high spatial resolution, high strain resolution, large strain range, and an extended sensing range presents an exceedingly challenging endeavor. In this study, we introduce and experimentally demonstrate a data and physics-driven neural network-empowered OFDR system designed to attain high-performance distributed sensing. In our experiments, we successfully maintained an impressive sensing resolution of sub-microstrain (0.91 µε) alongside a sharp spatial resolution of sub-millimeter (0.857 mm) across a 140-m sensing …

Geometrically Exact Beam Theory For Gradient-Based Optimization, Taylor Mcdonnell, Andrew Ning

Faculty Publications

Decades of research have progressed geometrically exact beam theory to the point where it is now an invaluable resource for analyzing and modeling highly flexible slender structures. Large-scale optimization using geometrically exact beam theory remains nontrivial, however, due to the inability of gradient-free optimizers to handle large numbers of design variables in a computationally efficient manner and the difficulties associated with obtaining smooth, accurate, and efficiently calculated design sensitivities for gradient-based optimization. To overcome these challenges, this paper presents a finite-element implementation of geometrically exact beam theory which has been developed specifically for gradient-based optimization. A key feature of this …

Development Of A Rule-Based Monitoring System For Autonomous Heavy Equipment Safety, Amirpooya Shirazi

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Roadway construction work zones are constantly exposed to interactions among construction equipment, workers, and vehicles. Furthermore, ensuring safety in these areas is considered a challenging task due to the complexity of the environment. As shown in the rising trend of fatal accidents in roadway work zones, current OSHA regulations in construction safety are insufficient in effectively detecting unsafe situations and mitigating the risks. Furthermore, best practices, such as internal traffic control planning (ITCP), exhibit critical limitations requiring continuous monitoring of active work zones as well as adjustments to the site coordination plans due to the dynamic nature of work zone …

Unmanned Aerial Vehicle (Uav)-Based High-Throughput Phenotyping For Maize Improvement, Eric T. Rodene

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Modern breeding programs rely heavily on efficiently screening large numbers of genotypes for agronomic traits, such as disease resistance, drought tolerance, and yield. Identifying the genetic loci or genes associated with these traits using GWAS or functional analyses will benefit future plant breeding efforts seeking to incorporate these traits into new crop varieties, whether through conventional breeding or gene editing techniques. Unmanned aerial vehicle (UAV)-based image data has been increasingly used for this task, as it allows entire test plots to be quickly and cost-effectively phenotyped. In my research, I have developed methods to improve the accuracy of machine learning …

Growth And Simulation Of Dielectric-Metal Nanoheterostructured Thin Films By Ballistic Deposition, Shawn Wimer

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This thesis is divided into two related topics: the structural and chemical characterization of dielectric-metal nanoheterostructured thin films grown by glancing angle deposition (GLAD) and the results of the simulated growth of films and structures by GLAD with discrete-space and continuous-space Monte Carlo ballistic simulation.

Individual structures comprising films grown by GLAD were investigated by S/TEM and SEM imaging, electron diffraction, and chemical characterization and mapping by EDX. Different intermolecular interactions within and between different materials, including Si, Ag, Au, and ZrO₂, are linked to differences in the shapes of individual materials in heterostructures, the shape of heterostructures …

Laser 3d Printing Of Diamond-Based Composite Materials For Thermal Management Applications, Nada Kraiem

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

With the trend towards miniaturization of electrical equipment and the constant increase in power density in semiconductor devices, efficient heat management has become a major concern for researchers. Indeed, this technological evolution imposes increasingly strict constraints in terms of thermal dissipation, necessitating innovative solutions to ensure better durability and reliability of components. In this context, the use of composite materials offering high thermal conductivity (TC) and low coefficient of thermal expansion (CTE) compared to pure metals has become essential to address overheating issues in electronic components.

The utilization of advanced materials such as diamond (D), with exceptional TC and hardness …

Advancements In Microscale Tensile Testing: A Novel Device For The High Throughput Analysis Of Two-Photon Polymerized Microfibers In Liquid, Grayson D. Minnick

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Two-photon polymerization (TPP) enables the 3D fabrication of micro- and nanostructures from biocompatible materials with high resolutions, reaching into the realm of hundreds of nanometers. Such capabilities are crucial for advancing applications in fields like mechanobiology. As microscale technologies evolve, the precise characterization of material properties becomes increasingly essential. This is especially true for TPP-printed microstructures serving as scaffolds for 3D cell culture and intended for studying the mechanics of tissues. Despite the importance, traditional micro-scale tensile testing methods typically lack scalability and fail to replicate relevant environmental conditions. This dissertation introduces a new device that is specifically designed to …