Engineering Commons^™

Dynamic Tire Response And The Effect On Roughness-Induced Vehicle Energy Dissipation, Gabriela Ann Lukanus

Master's Theses (2009 -)

Vehicle dynamics models rely on accurate inputs to quantify dynamic loading and energy dissipation to design pavement structures and assess the environmental impacts. The tire’s response to loading is one of the inputs used in these models, and it is typically represented by a linear spring and dashpot connected in parallel. However, tires are made of rubber, a viscoelastic material, so their load response depends on the excitation frequency. Yet, existing models do not incorporate this parameter. This thesis will first examine the load response and its variation with excitation frequency of two truck tires – a dual tire assembly …

Deep Learning Classification Of Deep Ultraviolet Fluorescence Images For Margin Assessment During Breast Cancer Surgery, Tyrell To

Master's Theses (2009 -)

Breast-conserving surgery (BCS) is a widely used treatment for breast cancer, but ensuring the complete removal of cancer cells from the surgical margins remains a challenge. Deep ultraviolet (DUV) fluorescence scanning microscopy offers a potential solution by providing real-time whole-surface imaging of resected tissues during BCS. However, interpreting DUV images for margin assessment requires an automated classification method. This dissertation addresses this need by proposing a deep learning-based classification approach for DUV fluorescence images in intra-operative margin assessment of breast cancer.To overcome the limited availability of DUV image datasets and potential over- fitting, the study combines patch-level classification using transfer …

Reducing Porosity In Lpbf Ti-6al-4v By Parameter Optimization And Low Temperature Hot Isostatic Pressing Cycle, Penn Rawn

Master's Theses (2009 -)

Powder bed based additive manufacturing has advantages in its ability to make specialized parts with complex geometries. Unfortunately, components made through such processes of suffer from manufacturing defects including porosity. To study pore formation and removal, specimens of Ti-6Al-4V were built at varied levels of laser power, travel speed, hatch spacing, and layer thickness to obtain a variety of initial defect populations. The specimens were then subjected to a hot isostatic pressure (HIP) at 850 °C and 200 MPa to evaluate the low temperature high pressure (LTHP) cycle’s ability to remove pores. Image analysis was used to estimate the relative …

Engineering Heterogeneous Nucleation During Solidification Of Multiphase Cast Alloys: An Overview, Simon (Semen) N. Lekakh, Jingjing Qing

Materials Science and Engineering Faculty Research & Creative Works

The theory of heterogeneous nucleation was initially developed as a part of condensed matter physics, and later it was used as an important engineering tool to design metallurgical processes. This success has led to wide applications of the theory in metallurgical practice. For example, engineering heterogeneous nucleation in ductile iron has been used to reduce shrinkage defects, suppress cementite formation, and modify the size and shape of microstructural constituencies. This demonstrates how theoretical knowledge could benefit industry practice. This overview aims to summarize the authors' published studies in co-authorship with colleagues and students, which covers different aspects of engineering heterogeneous …

Mechanisms Of Theta Burst Transcranial Ultrasound Induced Plasticity In The Human Motor Cortex, Yazan Shamli Oghli, Talyta Grippe, Tarun Arora, Tasnuva Hoque, Ghazaleh Darmani, Robert Chen

Department of Medicine Faculty Papers

BACKGROUND: Transcranial ultrasound stimulation (TUS) is a novel non-invasive brain stimulation technique with high depth penetrance and spatial resolution. Theta-burst TUS (tbTUS) is a plasticity-inducing protocol which increases motor cortical excitability for up to 30 min following 80s of sonication. While this protocol may have therapeutic potential for the treatment of psychiatric and neurological disorders, the mechanisms of action of TUS remain unclear.

OBJECTIVE: We conducted the first pharmacological study to examine the mechanisms of TUS in human primary motor cortex. By administering brain-active drugs with known mechanisms of action, we aimed to elucidate the mechanisms of tbTUS.

METHODS: Fourteen …

Construction Of A Real-Time Forecast Model With Deep Learning Techniques For Coastal Engineering & Processes: Nested In Basin Scale Suite Of Models, Md Ahsan Habib

Theses and Dissertations

The study aims to develop a robust and adaptable real-time forecasting system for coastal and estuarine regions, considering the challenges of limited or unavailable forecast data. To address the challenge of data unavailability, this study proposes the application of a deep learning model (DLM). This research involves the development of a high-resolution numerical model nested within global models. Calibration and validation are performed by comparing the model with observed data. The study explores the effects of various parameters, such as vertical resolution, wind variability, and bottom roughness, on model performance. It finds that the 10-layer model improves vertical stratification and …

Initial Investigation Of Using The Waste Rubber Tires As A New Sustainable Material For Electric Conductive Rigid Pavement, Islam Radwan

Theses and Dissertations

The accumulation of snow on roadway surfaces has the potential to result in deadly accidents and financial damage. Traditional de-icing procedures, which include the use of chemicals or salt and the use of heavy machinery, may have a negative effect on the environment and the structural integrity of highway infrastructure systems, and they are not sustainable at all. In addition, these methods are considered labor-intensive and dangerous, especially in crowded areas. The use of heated pavement systems (HPS), which can be in the form of hydronic (HHPS) or electrically conductive concrete (ECON), has gained popularity in recent years as a …

Impacts Of Land Use On Stormwater Runoff In The Lower Rio Grande Valley And Improving Long Term Municipal Stormwater Management Systems, Maria Vanessa Pruneda

Theses and Dissertations

Exponentially noticeable growth in population and land development in the Lower Rio Grande Valley has directly influenced growth in urbanization. Urbanization is the leading cause for lower pervious cover, and the increase in storm water runoff. The increase of storm water runoff leads to excess flooding areas and higher peak flows. The overflow flows freely and is exposed to contaminants, affecting the consumption and use factors. The changes of land use have a direct relationship with impervious cover limitations and individual site retentions. This study will assess the relationship between stormwater quantity and land use in the Lower Rio Grande …

Utrgv Edinburg Campus Two-Dimensional Flood Modeling For Development Of Flood Inundation Map, Roxana Tello

Theses and Dissertations

Severe flooding is a natural hazard worldwide, potentially subjecting people to life threatening situations and leaving infrastructure vulnerable to structural damage or complete destruction. The common threat of flooding poses constant challenges for state and local agencies in identifying flood risks and proposing the necessary mitigation improvements. Developing hydraulic models to predict the hydrological interactions and identify areas at risk is a beneficial tool for urban planning. The Lower Rio Grande Valley (LRGV) is a rapid growing region in South Texas along the border of Mexico and west of the Gulf of Mexico. The LRGV has historically suffered through various …

A Data-Driven Method For Damage Detection In An Open Deck Steel Truss Railroad Bridge Under The Moving Train Load, Mahesh Pokhrel

Theses and Dissertations

Open-Deck (OD) steel truss railroad bridges are one of the most common types of railroad bridges in the United States. They are, however, significantly vulnerable to the dynamic effects of moving train load. In the long run, these dynamic effects cause fatigue damage to the structural members. The damage in most of the railroad bridges are monitored by visual inspections which are sometimes unreliable and inconsistent due to human error. This study explores the identification and classification of damage to an open deck railroad bridge from both time-domain (statistical features) and time-frequency domain features (Hilbert-Huang Transform) extracted through acceleration response …

Image Segmentation With Human-In-The-Loop In Automated De-Caking Process For Powder Bed Additive Manufacturing, Vincent Opare Addo Asare-Manu

Theses and Dissertations

Additive manufacturing (AM) becomes a critical technology that increases the speed and flexibility of production and reduces the lead time for high-mix, low-volume manufacturing. One of the major bottlenecks in further increasing its productivity lies around its post-processing procedures. This work focuses on tackling a critical and inevitable step in powder-bed additive manufacturing processes, i.e., powder cleaning or de-caking. Pressing concerns can be raised with human involvement when performing this task manually. Therefore, a robot-driven automatic powder cleaning system could be an alternative to reducing time consumption and increasing safety for AM operators. However, since the color and surface texture …

Measurements Of Ear-Canal Geometry From High-Resolution Ct Scans Of Human Adult Ears, Auden P. Balouch, Karen Bekhazi, Hannah E. Durkee, Rebecca M. Farrar, Mealaktey Sok, Douglas H. Keefe, Aaron K. Remenschneider, Nicholas J. Horton, Susan E. Voss

Engineering: Faculty Publications

Description of the ear canal’s geometry is essential for describing peripheral sound flow, yet physical measurements of the canal’s geometry are lacking and recent measurements suggest that older-adult-canal areas are systematically larger than previously assumed. Methods to measure ear-canal geometry from multi-planar reconstructions of high-resolution CT images were developed and applied to 66 ears from 47 subjects, ages 18–90 years. The canal’s termination, central axis, entrance, and first bend were identified based on objective definitions, and the canal’s cross-sectional area was measured along its canal’s central axis in 1-2 mm increments. In general, left and right ears from a given …

A Comparative Effectiveness Study On Opioid Use Disorder Prediction Using Artificial Intelligence And Existing Risk Models, Sajjad Fouladvand, Jeffery Talbert, Linda Phyliss Dwoskin, Heather M. Bush, Amy L. Meadows, Lars E. Peterson, Yash R. Mishra, Steven K. Roggenkamp, Fei Wang, Ramakanth Kavuluru, Jin Chen

Markey Cancer Center Faculty Publications

Opioid use disorder (OUD) is a leading cause of death in the United States placing a tremendous burden on patients, their families, and health care systems. Artificial intelligence (AI) can be harnessed with available healthcare data to produce automated OUD prediction tools. In this retrospective study, we developed AI based models for OUD prediction and showed that AI can predict OUD more effectively than existing clinical tools including the unweighted opioid risk tool (ORT). Data include 474,208 patients’ data over 10 years; 269,748 were females with an average age of 56.78 years. Cases are prescription opioid users with at least …

Analysis, Measurement, And Modeling Of Millimeter Wave Channels For Aviation Applications, Zeenat Afroze

Theses and Dissertations

Millimeter wave (mmWave) communication systems can employ a large amount of spectrum, and can consequently offer large data rates, e.g., multi-Gigabits-per-second. This technology can be used in many sectors: aviation, vehicles, public transportation, robotics, autonomous factories, etc. Yet mmWave communication systems suffer from some propagation challenges, including large free space path loss (PL), large penetration loss, and large diffraction loss. Hence, it is vital to quantify these and other channel effects to ensure link reliability. Most mmWave systems will employ directional antennas to enable acceptable link distances. In many settings this will require directional receiver antennas to rotate in azimuth …

Building Services Engineering July/August 2023

Building Services Engineering

No abstract provided.

Development Of A Scalable Edge-Cloud Computing Based Variable Rate Irrigation Scheduling Framework, Eric J. Wilkening, Derek M. Heeren, Yeyin Shi, Abia Katimbo, Precious N. Amori, Guillermo R. Balboa, Laila A. Puntel, Kuan Zhang, Daran R. Rudnick

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Currently, variable-rate precision irrigation (VRI) scheduling methods require large amounts of data and processing time to accurately determine crop water demands and spatially process those demands into an irrigation prescription. Unfortunately, irrigated crops continue to develop additional water stress when the previously collected data is being processed. Machine learning is a helpful tool, but handling and transmitting large datasets can be problematic; more rural areas may not have access to necessary wireless data transmission infrastructure to support cloud interaction. The introduction of “edge-cloud” processing to agricultural applications has shown to be effective at increasing data processing speed and reducing the …

Uncertainty In Overturning Of Precariously Balanced Rocks Due To Basal Contact, M. Khalid Saifullah, Christine E. Wittich

Department of Civil and Environmental Engineering: Faculty Publications

Precariously balanced rocks (PBRs) are a type of naturally occurring freestanding structure that provides valuable information to constrain seismic hazard at return periods which are important for critical facilities such as nuclear power plants and nuclear repositories. Exposure ages have been established to be in excess of 10,000–30,000 years, which is why precarious rocks are one of the only available means to validate seismic hazard associated with long return periods. One critical component for constraining seismic hazard in this way is the overturning estimate of a given precarious rock as a function of earthquake intensity. However, current state-of-the-art methods for …

Balanced Blended Space: Foundational Human–Ai Dialogues In A Symmetry-Based Mediation Framework, David Smith

Publications and Research

This working paper documents the early development of the Balanced Blended Space (BBS) framework through a series of iterative interactions between a cognitive agent (human researcher) and a computational agent (AI system) conducted in 2023. The work is motivated by the need for a universal theoretical model capable of describing the integration of physical, virtual, and conceptual spaces, particularly in response to increasing fragmentation across contemporary communication systems.

BBS is proposed as a symmetry-based mediation framework in which relationships between domains—such as physical and virtual space, cognition and computation, and multiple sensory modalities—are treated as structurally equivalent and mappable. Central …

In-Situ Thermal And Deformation Characterization Of Additive Manufacturing Processes, Nicholas Phillips

Doctoral Dissertations and Master's Theses

Additive manufacturing (AM) is a rapidly growing industry with numerous applications in the aerospace industry such as aircraft parts and emergency tools on the International Space Station. Defects in additively manufactured structures, however, can waste a lot of time and money. Being able to monitor the manufacturing process for defects is one of the first steps which can be taken to mitigate these losses. This study focuses on the use of thermography in conjunction with deep learning to identify flaws during 3D printing of composite structures made using Onyx, a mixture of chopped carbon fiber and nylon, composite prints. In …

Freestanding Graphene Heat Engine Analyzed Using Stochastic Thermodynamics, J. Durbin, J. M. Mangum, M. N. Gikunda, F. Harerimana, P. Kumar, L. L. Bonilla, P. M. Thibado

Physics Faculty Publications and Presentations

We present an Ito-Langevin model for freestanding graphene connected to an electrical circuit. The graphene is treated as a Brownian particle in a double-well potential and is adjacent to a fixed electrode to form a variable capacitor. The capacitor is connected in series with a battery and a load resistor. The capacitor and resistor are given separate thermal reservoirs. We have solved the coupled Ito-Langevin equations for a broad range of temperature differences between the two reservoirs. Using ensemble averages, we report the rate of change in energy, heat, and work using stochastic thermodynamics. When the resistor is held at …

A Hierarchical Optimization Approach For Dynamic Pickup And Delivery Problem With Lifo Constraints, Jianhui Du, Zhiqin Zhang, Xu Wang, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We consider a dynamic pickup and delivery problem (DPDP) where loading and unloading operations must follow a last in first out (LIFO) sequence. A fleet of vehicles will pick up orders in pickup points and deliver them to destinations. The objective is to minimize the total over-time (that is the amount of time that exceeds the committed delivery time) and total travel distance. Given the dynamics of orders and vehicles, this paper proposes a hierarchical optimization approach based on multiple intuitive yet often-neglected strategies, namely what we term as the urgent strategy, hitchhike strategy and packing-bags strategy. These multiple strategies …

Effect Of Nanoparticle Loading And Magnetic Field Application On The Thermodynamic, Optical, And Rheological Behavior Of Thermoresponsive Polymer Solutions, Christopher A. P. Neal, Grace V. Kresge, Michelle C. Quan, Valeria León, Nondumiso O. Chibambo, Michelle A. Calabrese

Mechanical Engineering Faculty Publications

Although processing via external stimuli is a promising technique to tune the structure and properties of polymeric materials, the impact of magnetic fields on phase transitions in thermoresponsive polymer solutions is not well-understood. As nanoparticle (NP) addition is also known to impact these thermodynamic and optical properties, synergistic effects from combining magnetic fields with NP incorporation provide a novel route for tuning material properties. Here, the thermodynamic, optical, and rheological properties of aqueous poly(N-isopropyl acrylamide) (PNIPAM) solutions are examined in the presence of hydrophilic silica NPs and magnetic fields, individually and jointly, via Fourier-transform infrared spectroscopy (FTIR), magneto-turbidimetry, …

A Direct Fiber Approach To Model Sclera Collagen Architecture And Biomechanics, Fengting Ji, Manik Bansal, Bingrui Wang, Yi Hua, Mohammad R. Islam, Felix Matuschke, Markus Axer, Ian A. Sigal

Mechanical Engineering Faculty Publications

Sclera collagen fiber microstructure and mechanical behavior are central to eye physiology and pathology. They are also complex, and are therefore often studied using modeling. Most models of sclera, however, have been built within a conventional continuum framework. In this framework, collagen fibers are incorporated as statistical distributions of fiber characteristics such as the orientation of a family of fibers. The conventional continuum approach, while proven successful for describing the macroscale behavior of the sclera, does not account for the sclera fibers are long, interwoven and interact with one another. Hence, by not considering these potentially crucial characteristics, …

Lift Force Analysis For An Electrodynamic Wheel Maglev Vehicle, Colton W. Bruce, Jonathan Bird, Matthew K. Grubbs

Electrical and Computer Engineering Faculty Publications and Presentations

This paper used an analytic based 3-D second order vector potential model to study the vertical dynamic force ripple and dynamic airgap height change when using a one pole-pair electrodynamic wheel (EDW) maglev vehicle. A one-pole pair EDW creates the lowest lift specific power; however transient finite element analysis (FEA) also shows that the one pole-pair EDW will create a large oscillating vertical force when maintaining a static airgap height. A dynamically coupled eddy current model was used to confirm that when the airgap length is allowed to change with time then an increase in vertical airgap creates a large …

Progression Of Surface Flashover In Vacuum With Polymer Insulators, Kimberly M. Faris

Electrical and Computer Engineering ETDs

In pulsed power devices, an insulator is needed to isolate the transmission line from vacuum chambers. Vacuum is used as the insulator because it contains no atoms. Since it is being used as an insulator in these pulsed power insulation systems, surface flashover in vacuum is one of the most extensively studied areas since it being the greatest constraint in providing power due to dielectrics that are not able to sustain the voltage the system is operating under. These dielectrics are used in between high voltage electrodes in various pulsed power applications as electrical insulators to limit the electric current …

An Effective Heuristic To Reduce Total Flowtime For Randomly-Structured Flowshop Problems, Arun John Abraham

Theses

We propose a heuristic to reduce total flowtime in a six-job, four-machine permutation flowshop scheduling problem. This work contributes to the prolific research efforts reported in the permutation flowshop scheduling problem (PFSP).

The heuristic was applied to 102 randomly structured flowshop scheduling problems, with job processing times generated using an integer uniform distribution in the interval [1,100]. The results of computational experiments were deemed satisfactory after being evaluated by using the ordinal and percentile ranks of the resulting total flowtime for the six jobs.

The Role Of Lithium In The Aging Precipitation Process Of Al-Zn-Mg-Cu Alloys And Its Effect On The Properties, Jing-Ran Sun, Bai-Xin Dong, Hong-Yu Yang, Shi-Li Shu, Feng Qiu, Qi-Chuan Jiang, Lai-Chang Zhang

Research outputs 2022 to 2026

It is well known that the development of lightweight alloys with improved comprehensive performance and application value are the future development directions for the ultra-high-strength 7xxx series Al-Zn-Mg-Cu alloys used in the aircraft field. As the lightest metal element in nature, lithium (Li) has outstanding advantages in reducing the density and increasing the elastic modulus in aluminum alloys, so Al-Zn-Mg-Cu alloys containing Li have gained widespread attention. Furthermore, since the Al-Zn-Mg-Cu alloy is usually strengthened by aging treatment, it is crucial to understand how Li addition affects its aging precipitation process. As such, in this article, the effects and mechanism …

On The Stability Of Rubble Mound Structures Under Oblique Wave Attack, Meysam Bali, Amir Etemad-Shahidi, Marcel R. A. Van Gent

Research outputs 2022 to 2026

Slope stability formulae for rubble mound structures are usually developed for head-on conditions. Often, the effects of oblique waves are neglected, mainly because it is assumed that for oblique wave attack, the reduction in damage compared to perpendicular wave attack is insignificant. When the incident waves are oblique, the required armour size can be reduced compared to the perpendicular wave attack case. Therefore, it is important to consider the wave obliquity influence on slope stability formulae as a reduction factor. One of the most recent formulae for estimating the stability of rock-armoured slopes, referred to as Etemad-Shahidi et al. (2020), …

Development Of Intensity Duration Frequency Curve Of The Lower Rio Grande Valley, Binaya Poudel

Theses and Dissertations

Section 1: This chapter incorporates extensive information about the concept of Intensity-Duration-Frequency (IDF) curves, their historical development and usage, specific focus on the Lower Rio Grande Valley, and the importance of using a comprehensive 32-year data set from 1990-2022 to develop these curves.

Section 2: This chapter provides detailed information about the rigorous comparison of the developed IDF curves with previous ones, where past IDF curves were developed using an empirical formula method. The research presented here employs the Gumbel distribution method, providing a fresh perspective and potentially more accurate predictions of future weather extremes.

Section 3: This chapter outlines …

Optimization Of Ultrawide Bandgap Semiconductor Materials For Heterostructure Field Effect Transistors (Hfets), Mohi Uddin Jewel

Theses and Dissertations

Ultra-wide bandgap (UWBG) gallium oxide (Ga2O3), and aluminum gallium oxide (Al_xGa_1-x)₂O₃ materials with bandgap E_G ≥ 4.8 eV are promising for heterostructure field effect transistors (HFETs) with high breakdown voltage and operating at high temperatures. Despite some initial breakthroughs in good quality β-Ga₂O₃ thin films growth on (001), (100), (010), and (201) β-Ga₂O₃ substrates, and promising results on β- (Al_xGa_1-x)₂O₃/β-Ga₂O₃ HFETs fabricated on (010) β-Ga₂O₃ substrates, heat dissipation in Ga2O3 materials and …