Engineering Commons^™

Full Functionality And Recovery Assessment Framework For A Hospital Subjected To A Scenario Earthquake Event, Emad M. Hassan, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Modeling the recovery process of a community's infrastructure after the occurrence of extreme events is now at the forefront of research. Estimating post-disaster recovery of either single or multiple infrastructure in a community requires proper flow and interaction of information of the physical, economic and social components of the involved sectors. Understanding this recovery process is essential, particularly for critical infrastructure, such as a hospital, which is vital for a community's well-being. In this study, the full seismic functionality and recovery process of a six-story hospital, located in Memphis, TN, is quantified and assessed using a comprehensive 3-D finite element …

Mud Loss Estimation Using Machine Learning Approach, Abo Taleb T. Al-Hameedi, Husam H. Alkinani, Shari Dunn-Norman, Ralph E. Flori, Steven Austin Hilgedick, Ahmed S. Amer, Mortadha Alsaba

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Lost circulation costs are a significant expense in drilling oil and gas wells. Drilling anywhere in the Rumaila field, one the world's largest oilfields, requires penetrating the Dammam formation, which is notorious for lost circulation issues and thus a great source of information on lost circulation events. This paper presents a new, more precise model to predict lost circulation volumes, equivalent circulation density (ECD), and rate of penetration (ROP) in the Dammam formation. A larger data set, more systematic statistical approach, and a machine-learning algorithm have produced statistical models that give a better prediction of the lost circulation volumes, ECD, …

Global Engineering And Language Attitudes In The U.S.: A Quandary, Jorge Porcel

Arts, Languages and Philosophy Faculty Research & Creative Works

No abstract provided.

The Effect Of Testing Conditions On The Performance Of Lost Circulation Materials: Understandable Sealing Mechanism, Montri Jeennakorn, Mortadha Alsaba, Runar Nygaard, Arild Saasen, Olav Magnar Nes

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Lost circulation materials (LCMs) are added to drilling fluids to mitigate lost circulation (LOC) problems. Designing the fluid requires a good understanding of sealing mechanisms and all the parameters affecting the sealing performance. Laboratory testing apparatus is the key concept for LCM evaluation ensuring successful treatment. The high-pressure test cell containing fracture discs is an effective tool among the broadly designed apparatus. A variety of formulations has been developed from the LCM physical properties. Recently, the testing conditions such as the slot wall angles, and the fracture disc thickness were found to have significant effects on the evaluation results. However, …

Affordable Learning Solutions And Interactive Content In Engineering Mechanics, Nicolas Ali Libre

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Digital Affordable Learning Solutions (ALS) provides students with quality yet affordable educational content and enables instructors to utilize multimedia and interactive technology as effective ways of delivering course material. The reduced course content expenses not only allow more students to access the educational material, but also permit the instructors to customize and adapt the material to their teaching style. Incorporation of interactive technology through visually appealing media such as animations, graphics, simulations, videos, and three-dimensional models promotes students' interest in learning theoretical and abstract subjects in science and engineering. In this study, the incorporation of an interactive eBook as an …

Problem-Based Learning As A Pedagogy For Individual Students -- Quantifying The Long-Term Effects Of Land Subsidence And Rising Sea Levels In Coastal Areas For Greater Student Engagement, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Course-based class discussions usually are limited to course syllabus and topics of lectures. If a discussion goes beyond course syllabus and the topics, usually there is a time constraint of class/lab periods, keeping educators and students from going deeper. Even without time constraints of class/lab settings, some students get engaged in the overall learning process more when they are challenged or tasked to solve a problem. This paper focuses on the pedagogical aspect of problem-based learning and its application for greater engagement of these students in quantifying the long term effects of land subsidence and rising sea levels in coastal …

Utility Of Reading Assignments In Environmental Engineering Education For Effective Learning And Greater Student Engagement In An Era Of Innovative Pedagogy And Emerging Technologies, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Making teaching more effective has been a never-ending pursuit since the dawn of education. Engineering education is no exception to this. There have been numerous pedagogical advances making engineering education more effective. Most engineering majors, some more than others, have dedicated laboratories for hands-on learning of specific concepts and techniques. However, a major portion of teaching still takes places in classroom settings. Educators adopt various pedagogical practices, teaching-aids, and technologies to engage students in the controlled environment of classrooms. In ideal class settings, an instructor should be able to reach out to all students regardless of their learning styles. Introductory …

Uav/Satellite Multiscale Data Fusion For Crop Monitoring And Early Stress Detection, V. Sagan, M. Maimaitijiang, P. Sidike, M. Maimaitiyiming, H. Erkbol, S. Hartling, K. T. Peterson, J. Peterson, Joel Gerard Burken, F. Fritschi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Early stress detection is critical for proactive field management and terminal yield prediction, and can aid policy making for improved food security in the context of climate change and population growth. Field surveys for crop monitoring are destructive, labor-intensive, time-consuming and not ideal for large-scale spatial and temporal monitoring. Recent technological advances in Unmanned Aerial Vehicle (UAV) and high-resolution satellite imaging with frequent revisit time have proliferated the applications of this emerging new technology in precision agriculture to address food security challenges from regional to global scales. In this paper, we present a concept of UAV and satellite virtual constellation …

Analysis Of The Topological Photonic Crystals Using Finite-Difference Supercell Approach, Menglin L.N. Chen, Li (Lijun) Jun Jiang, Zhihao Lan, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

Topological photonic systems have been explored extensively due to the robust electromagnetic states they support. In this work, we propose a finite-difference supercell approach to analyze the topological property of photonic crystal (PC) structures. Meanwhile, the pseudospin polarized edge states at the interface of two PC structures with different topologies are studied. The direction of the energy flow is found to be determined by the helicity of the pseudospin polarization.

Source Reconstruction Method Based On Machine Learning Algorithms, He Ming Yao, Lijun Jiang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a new source reconstruction method (SRM) based on deep learning. The conventional SRM usually requires oversampled measurements data to ensure higher accuracy. Thus, conventional SRM numerical system is usually highly singular. A deep convolutional neural network (ConvNet) is proposed to reconstruct the equivalent sources of the target to overcome difficulty. The deep ConvNet allows us to employ less data samples. Besides, the ill-conditioned numerical system can be effectively avoided. Numerical examples are presented to demonstrate the feasibility and accuracy of the proposed method. Its performance is also compared with the traditional neural network and interpolation method. Moreover, …

Empirical And Theoretical Analysis Of Solar Devices In Public Spaces, Justin Morgan Roberts

Theses and Dissertations

With the debate on global warming and climate change, renewable energy resources, such as solar energy, are being considered. If solar energy is to make a major utility contribution, it will need to be more ubiquitous in today’s society. The research described hereafter analyzes the use of Solar in Public Spaces (SPS). SPS is defined as solar energy used in the public domain to power electronics away from the electric grid. This research specifically examines the viability of integrating solar panels into existing surfaces to charge portable electronics. Viability is evaluated using three criteria: (1) user interaction, (2) technical feasibility, …

An Integrated Model To Use Drilling Modular Machine Tools, Ana Vafadar, Majid Tolouei-Rad, Kevin Hayward

Research outputs 2014 to 2021

Modular machine tools provide a platform for drilling-related operations within automotive companies. The use of these machine tools is widespread; however, manufacturers wishing to use this technology frequently face the challenge of selecting the most appropriate manufacturing system. Accordingly, a comprehensive feasibility analysis procedure is required to assist decision-makers before any investment is made on the preparation of detailed machine design or purchase one. This paper presents a model, which collects the previous works of the authors. To do this, an integrated framework for decision-making of using machine tools is developed. The aim of this model is to enable users …

Blind Separation For Intermittent Sources Via Sparse Dictionary Learning, Annan Dong

Dissertations

Radio frequency sources are observed at a fusion center via sensor measurements made over slow flat-fading channels. The number of sources may be larger than the number of sensors, but their activity is sparse and intermittent with bursty transmission patterns. To account for this, sources are modeled as hidden Markov models with known or unknown parameters. The problem of blind source estimation in the absence of channel state information is tackled via a novel algorithm, consisting of a dictionary learning (DL) stage and a per-source stochastic filtering (PSF) stage. The two stages work in tandem, with the latter operating on …

Probabilistic Spiking Neural Networks : Supervised, Unsupervised And Adversarial Trainings, Alireza Bagheri

Dissertations

Spiking Neural Networks (SNNs), or third-generation neural networks, are networks of computation units, called neurons, in which each neuron with internal analogue dynamics receives as input and produces as output spiking, that is, binary sparse, signals. In contrast, second-generation neural networks, termed as Artificial Neural Networks (ANNs), rely on simple static non-linear neurons that are known to be energy-intensive, hindering their implementations on energy-limited processors such as mobile devices. The sparse event-based characteristics of SNNs for information transmission and encoding have made them more feasible for highly energy-efficient neuromorphic computing architectures. The most existing training algorithms for SNNs are based …

Electrochemically Reactive Membranes For Efficient Biomass Recovery, Pollutant Degradation And Commercialization, Likun Hua

Dissertations

Micropollution in natural waters such as rivers and groundwater aquifers is a widespread problem that prevents these potentially potable sources from being used as drinking water. In the United States, approximately two-thirds of the over 1,200 most serious hazardous waste sites in the nation are contaminated with trichloroethylene (TCE), a potentially carcinogenic compound. Other emerging and environmentally persistent organic micropollutants include polyromantic hydrocarbons (PAHs), organophosphate flame retardants, endocrine disrupting compounds (EDCs), pesticides, herbicides, pharmaceuticals and personal care products (PPCPs). Membrane filtration is one of the most efficient separation processes widely used for water treatment and pollutant removal. However, traditional membrane …

A Multimodal Approach To Investigate Brain Reorganization After Spinal Cord Injury Using Functional Magnetic Resonance Imaging And Functional Near-Infrared Spectroscopy, Keerthana Deepti Karunakaran

Dissertations

Traumatic Spinal Cord Injury (SCI) results in structural and functional neurological changes at both the brain and the level of the spinal cord. Anatomical studies indicate decreased grey matter volume in sensorimotor and non-sensorimotor regions of the cortex following SCI; whereas, neurophysiological findings mostly report altered functional activity in the sensorimotor nodes of the cortex, subcortex, and cerebellum. Therefore, it is currently unknown whether tissue atrophy observed in non-motor related areas has any concomitant functional consequences. Furthermore, the neural underpinnings of adaptive neuroplasticity after SCI is not well-defined in the current literature. Hence, this dissertation is a pioneer study investigating …

Supercapacitors With Gate Electrodes, Tazima Selim Chowdhury

Dissertations

A new approach to improve the capacitance of supercapacitors (SC) is proposed in this study. A typical SC is composed of an anode and a cathode; a separator in between them assures an unintentional discharge of the capacitor. The study focuses on a family of structured separators, either electronically active or passive which are called gates. An active structured separator layer has been fabricated and analyzed. The structured separator has characteristics of electrical diode and is fabricated out of functionalized carbon nanotubes (CNT). Improvement of the overall capacitance of SC, equipped with either active or passive structured separators demonstrated a …

Minimizing Vehicular Traffic Via Optimized Land Use Development For A Sustainable And Equitable Future, Babu Veeregowda

Dissertations

Mixed-use developments and transit-oriented developments are becoming very common in urban areas in an effort to reduce sprawl. Numerous studies have shown that such programs would not be successful unless the mix of land uses and sizes is well-balanced and integrated with the surrounding neighborhood. Developers often ignore this aspect in favor of immediate financial gain and do not realize that there are sustainable financial benefits in land use optimization. In addition, professionals often work with limited logistics, resources, and technical knowledge and therefore struggle in setting goals and suggesting land uses that have less auto dependency based on travel …

Dual Modality Optical Coherence Tomography : Technology Development And Biomedical Applications, Farzana Rahmat Zaki

Dissertations

Optical coherence tomography (OCT) is a cross-sectional imaging modality that is widely used in clinical ophthalmology and interventional cardiology. It is highly promising for in situ characterization of tumor tissues. OCT has high spatial resolution and high imaging speed to assist clinical decision making in real-time.

OCT can be used in both structural imaging and mechanical characterization. Malignant tumor tissue alters morphology. Additionally, structural OCT imaging has limited tissue differentiation capability because of the complex and noisy nature of the OCT signal. Moreover, the contrast of structural OCT signal derived from tissue’s light scattering properties has little chemical specificity. Hence, …

High-Performance Learning Systems Using Low-Precision Nanoscale Devices, Nandakumar Sasidharan Rajalekshmi

Dissertations

Brain-inspired computation promises a paradigm shift in information processing, both in terms of its parallel processing architecture and the ability to learn to tackle problems deemed unsolvable by traditional algorithmic approaches. The computational capability of the human brain is believed to stem from an interconnected network of 100 billion compute nodes (neurons) that interact with each other through approximately 10¹⁵ adjustable memory junctions (synapses). The conductance of synapses is modifiable allowing the network to learn and perform various cognitive functions. Artificial neural networks inspired by this architecture have demonstrated even super-human performance in many complex tasks.

Computational systems based …

Speciation Of Gaseous Oxidized Mercury Molecules Relevant To Atmospheric And Combustion Environments, Francisco J. Guzman

Dissertations

Mercury is a pervasive and highly toxic environmental pollutant. Major anthropogenic sources of mercury emissions include artisanal gold mining, cement production, and combustion of coal. These sources release mostly gaseous elemental mercury (GEM), which upon entering the atmosphere can travel long distances before depositing to environmental waters and landforms. The deposition of GEM is relatively slow, but becomes greatly accelerated when GEM is converted to gaseous oxidized mercury (GOM) because the latter has significantly higher water solubility and lower volatility. Modeling GOM deposition requires the knowledge of its molecular identities, which are poorly known because ultra-trace (tens to hundreds part …

Interventions Of Waterjet Technology In Skin Incisions, Nadi Atalla

Dissertations

This research explores the use of waterjet (WJ) technology in performing skin incisions. The study defines the analytical relationships between the skin properties and the operating parameters of the WJ which include the skin thickness, its elastic modulus, the WJ pressure, the nozzle’s orifice diameter, its stand-off distance and the traverse speed of the WJ as well as the duration of applying the WJ pressure. An analytical model is developed to measure the depth incision of the skin, the water pressure and the water velocity, while using a WJ. Systemization and optimization models that determine the optimal operating parameters levels …

Epitaxial Growth Of Iii-Nitride Nanostructures And Their Optoelectronic Applications, Moab Rajan Philip

Dissertations

Light-emitting diodes (LEDs) using III-nitride nanowire heterostructures have been intensively studied as promising candidates for future phosphor-free solid-state lighting and full-color displays. Compared to conventional GaN-based planar LEDs, III-nitride nanowire LEDs exhibit numerous advantages including greatly reduced dislocation densities, polarization fields, and quantum-confined Stark effect due to the effective lateral stress relaxation, promising high efficiency full-color LEDs. Beside these advantages, however, several factors have been identified as the limiting factors for further enhancing the nanowire LED quantum efficiency and light output power. Some of the most probable causes have been identified as due to the lack of carrier confinement in …

N8- Polynitrogen Stabilized On Carbon-Based Supports As Metal-Free Electrocatalyst For Oxygen Reduction Reaction In Fuel Cells, Zhenhua Yao

Dissertations

The sluggish oxygen reduction reaction (ORR) kinetics at the cathode is one of the key factors limiting the performance of polymer electrolyte membrane fuel cell (PEMFC). Platinum-based materials are the most widely studied catalysts for this ORR reaction while their large-scale practical application in fuel cells is hindered due to their scarcity and low stability. Therefore, highly active, low cost and robust non-Pt catalysts are being developed to overcome the drawbacks. Recently, a novel polynitrogen N8- (PN) stabilized on multiwall carbon nanotube (MWNT) was synthesized under ambient condition for the first time by our group and demonstrated high ORR activities. …

Surface-Enhanced Raman Detection Of Glucose On Several Novel Substrates For Biosensing Applications, Laila Saad Alqarni

Dissertations

The small normal Raman cross-section of glucose is considered to be a major challenge for its detection by Surface Enhanced Raman Spectroscopy (SERS) for medical applications. These applications include blood glucose level monitoring of diabetic patients and evaluation of patients with other medical conditions, since glucose is a marker for many human diseases. This dissertation focuses on Surface-Enhanced Raman Scattering primarily for the detection of glucose. Some experiments also are carried out for the detection of the corresponding enzyme glucose oxidase that is used in electrochemical glucose sensors and in biofuel cells. This project explores the possibility of utilizing Surface …

Workload Allocation In Mobile Edge Computing Empowered Internet Of Things, Qiang Fan

Dissertations

In the past few years, a tremendous number of smart devices and objects, such as smart phones, wearable devices, industrial and utility components, are equipped with sensors to sense the real-time physical information from the environment. Hence, Internet of Things (IoT) is introduced, where various smart devices are connected with each other via the internet and empowered with data analytics. Owing to the high volume and fast velocity of data streams generated by IoT devices, the cloud that can provision flexible and efficient computing resources is employed as a smart "brain" to process and store the big data generated from …

Fouling And Aging In Membrane Filtration : Hybrid Afm-Based Characterization, Modelling And Reactive Membrane Design, Wanyi Fu

Dissertations

Membrane filtration has been extensively used in water and wastewater treatment, desalination, dairy making, and biomass/water separation. However, membrane fouling, aging and insufficient removal efficiency for dissolved organic matters remain major challenges for wider industrial applications. In order to tackle these challenges, this doctoral dissertation investigates mechanisms of membrane fouling and development of antifouling membrane filtration technologies. Specifically, four major research areas are explored: (i) nanoscale physicochemical characterization of the chemically modified polymeric membranes; (ii) quantitative modelling between membrane properties and membrane fouling and defouling kinetics; (iii) development of quantitative structure-activity relationships for membranes that undergo thermal and chemical aging …

Design And Measurement Of A Millimeter-Wave 2d Beam Switching Planar Antenna Array, Benjamin Horwath

Engineering Ph.D. Theses

A millimeter-wave 2-D beam switching microstrip patch antenna array excited by a 4x4 substrate integrated waveguide (SIW) Modified Butler Matrix is designed and experimentally evaluated in this thesis. A novel architecture is introduced for the Butler Matrix feed network to give designers a choice for phase shifter location to pursue a smaller circuit area. In addition, it enables the designer to control the BM phased outputs for achieving a set of desired 2-D beam directions, e.g., ϕ₀=45°, 135°, 225°, and 315° at θ₀=45°, with a passive beam switching network for a given array geometry. Full-wave simulation …

Engineered Excipients Via Dry Particle Coating, Liang Chen

Dissertations

Excipients with good flowability, bulk density as well as compaction properties are desired for use in tableting since they play important roles in formulation development and processing, including, handling, mixing, feeding and compaction. However, it is often difficult to manufacture excipients that simultaneously possess all three desirable properties, particularly if their size is fine. In addition, it is desirable that the excipients promote direct compression of poorly compactable fine cohesive drug powders at sufficiently high drug loading, and not just achieve the desired high functional properties in placebo formulations. This dissertation aims to developed engineered excipients towards this unmet industry …

Enzyme-Assisted Development Of Hydrogels As Medical Materials With Injectable, Biodegradable And Biocompatible Properties, Yung-Hao Tsou

Dissertations

Hydrogels were first discovered in the year 1960 by Wichterle and Lim [1], and in the following decades, they have been widely studied because of their unique characteristics including their hydrophilic nature, biocompatibility, and capacity to mimic the extracellular matrix (ECM). Hydrogels based on natural or synthetic polymers have continued to be of interest for tissue engineering and drug delivery due to their ability to encapsulate living cells and control the release rate of drugs or other bioactive molecules such as pharmaceutical proteins.

In the first part of this dissertation, dopant-free photoluminescent hydrogels formed in situ by crosslinking of biocompatible …