Engineering Commons^™

Implementation Of Multiscale Mechanisms In Finite Element Analysis Of Active Composite Structures, Amany Micheal, Yehia Bahei-El-Din

Centre for Advanced Materials

Interrogation of composite structures for inherent damage is investigated by implementing a three-tier analysis scheme. The analysis starts at the structure level where a general-purpose Finite Element code ABAQUS is employed to obtain the stress field in the second level of analysis which is the composite laminate. A special material routine is prepared to propagate the local fields to the individual plies and hence to the third level of analysis which is the microstructure modeling of the composite. Through the third level of analysis, interface damage between fiber and matrix is checked implementing a certain failure criteria. The interaction between …

Performance Of Wlan In Downlink Mu-Mimo Channel With The Least Cost In Terms Of Increased Delay, Lemlem Kassa, Jianhua Deng, Mark Davis, Jingye Cai

Articles

To improve the performance of IEEE 802.11 wireless local area (WLAN) networks, different frame-aggregation algorithms are proposed by IEEE 802.11n/ac standards to improve the throughput performance of WLANs. However, this improvement will also have a related cost in terms of increasing delay. The traffic load generated by mixed types of applications in current modern networks demands different network performance requirements in terms of maintaining some form of an optimal trade-off between maximizing throughput and minimizing delay. However, the majority of existing researchers have only attempted to optimize either one (to maximize throughput or minimize the delay). Both the performance of …

Development Of Gene Regulatory Elements For Biosensing Applications, Mallory N. Bates

Browse all Theses and Dissertations

21% of U.S adults experienced mental illnesses in 2020. Nearly 1 in 4 active- duty military personnel showed signs of mental health conditions in 2014 [89]. Mental health can be identified in the body by different biomarkers. These biomarkers potentially could be controlled by riboswitches, which could help mental illnesses and regulate diseases. Riboswitches are desirable in these cases due to responding without affecting vital functions. Riboswitches are located in mRNA and switch “ON” or “OFF” depending on the concentration of a biomarker [13]. In this research, riboswitches were re-engineered to take a known riboswitch and control its response in …

Design Of A Surrogate Hypersonic Inlet For The Hifire-6 Configuration, Joseph W. Mileski

Browse all Theses and Dissertations

Shock wave-boundary layer interactions can significantly impact the operability of high-speed inlets by inducing flow separation. This flow separation is difficult to visualize in three-dimensional, inward-turning inlets because of the curved surfaces that form their internal flow paths. To remedy this challenge, a surrogate test article was created. Using the results from a previously completed Computational Fluid Dynamic (CFD) analysis of the HIFiRE-6, a surrogate inlet with a rectangular isolator section was streamline-traced, allowing for the use of schlieren imagery to capture the separation bubble. This thesis discusses the process of developing the test article. Experimental results from a planned …

Design, Analysis, And Application Of Flipped Product Chaotic System, Md Sakib Hasan, Partha Sarathi Paul, Anurag Dhungel, Maisha Sadia, Md Razuan Hossain

Faculty and Student Publications

In this paper, a novel method is proposed to build an improved 1-D discrete chaotic map called flipped product chaotic system (FPCS) by multiplying the output of one map with the output of a vertically flipped second map. Two variants, each with nine combinations, are shown with trade-off between computational cost and performance. The chaotic properties are explored using the bifurcation diagram, Lyapunov exponent, Kolmogorov entropy, and correlation coefficient. The proposed schemes offer a wider chaotic range and improved chaotic performance compared to the constituent maps and several prior works of similar nature. Wide chaotic window and improved chaotic complexity …

Cascading Cmos-Based Chaotic Maps For Improved Performance And Its Application In Efficient Rng Design, Partha Sarathi Paul, Maisha Sadia, Md Razuan Hossain, Barry Muldrey, Md Sakib Hasan

Faculty and Student Publications

We present a general framework for improving the chaotic properties of CMOS-based chaotic maps by cascading multiple maps in series. Along with two novel chaotic map topologies, we present the 45 $nm$ designs for four CMOS-based discrete-time chaotic map topologies. With the help of the bifurcation plot and three established entropy measures, namely, Lyapunov exponent, Kolmogorov entropy, and correlation coefficient, we present an extensive chaotic performance analysis on eight unique map circuits (two under each topology) to show that under certain constraints, the cascading scheme can significantly elevate the chaotic performance. The improved chaotic entropy benefits many security applications and …

Ljm Rc Baja Vehicle Project Chassis And Suspension, Paul Lervick

All Undergraduate Projects

An RC car was designed, analyzed, and manufactured to compete in the ASME RC Baja competition. The focus was to optimize the suspension and chassis components to minimize the weight while maintaining the structural strength of the components which would intern supplement the overall speed and stability of the vehicle. Other components were the responsibility of the teammate Cam Jamison. To complete this there was extensive research done on Traxxas RC cars and what went into making a high-performing vehicle that would compete well in the 3 races that comprise the competition (slalom, sprint, and obstacle course). There were then …

Direct Femtosecond Laser Inscription Of High-Order Bragg Gratings In Fluoroaluminate Glass Fiber, Lin She, Niannian Xu, Pengfei Wang, Jiquan Zhang, Mo Liu, Nian Lv, Ruoning Wang, Zhenrui Li, Shijie Jia, Shunbin Wang, Gerald Farrell, Weimin Sun

Articles

This letter reports the fabrication of fiber Bragg gratings (FBGs) within in-house fabricated fluoroaluminate (AlF3) glass fibers using femtosecond (fs) laser inscription at 800 nm. The grating strength of the FBGs was investigated for different pulse energies and different orders, and a 3rd-order FBG with Bragg wavelength at 1557 nm was found to have the highest reflectivity of 99.5%. In addition, the reflectivity of the mid-IR grating peaks for different orders was also studied, and a 2nd-order FBG with a reflectivity of 98.8% was obtained at 2864 nm. Finally, the temperature characteristics of a mid-IR FBG were studied between 30 …

Recent Advances In Luminescence And Lasing Research In Zbya Glass, Changjun Xu, Jiquan Zhang, Mo Liu, Haiyan Zhao, Fengzi Ling, Shijie Jia, Gerald Farrell, Shunbin Wang, Pengfei Wang

Articles

In the last few decades, fluoride glasses have attracted a growing interest due to their unique advantages compared to multi-component oxide glasses. Among them, the most studied and widely used were fluorozirconate glasses, represented by ZrF4–BaF2–LaF3–AlF3–NaF (ZBLAN) glasses. However, compared with ZBLAN glasses, a kind of fluorozirconate glass with the components ZrF4–BaF2–YF3–AlF3 (ZBYA) has higher thermal and chemical stability. In this paper, we first introduce the advantages of ZBYA glasses compared to ZBLAN glasses. Then we review and discuss recent advances in research on luminescence and lasing in ZBYA glass and fiber. These studies suggest that ZBYA glass has strong …

All-Optical Modulator Based On A Microfibre Coil Resonator Functionalized With Mxene, Pengfei Wang, Shi Li, Fengzi Ling, Gerald Farrell, Elfed Lewis, Yu Yin

Articles

A novel all-optical modulator based on a microfibre coil resonator (MCR) functionalized using MXene is reported. The MCR was manufactured by winding a tapered fibre on a polycarbonate (PC) resin cylinder with low refractive index to support the microfibre, which also forms a fluidic channel coil. The MXene dispersion was injected into the channel to allow the deposition of an MXene layer using a photodeposition process. The transmission spectra were tuned using a tunable laser with a centre wavelength of 1550 nm and the light-matter interaction resulting from the photo-thermal effect and MXene absorption provide the all-optical modulation in this …

A Micron-Range Displacement Sensor Based On Thermo-Optically Tuned Whispering Gallery Modes In A Microcapillary Resonator, Zhe Wang, Arun Kumar Mallik, Fangfang Wei, Zhuochen Wang, Anuradha Rout, Qiang Wu, Yuliya Semenova

Articles

A novel micron-range displacement sensor based on a whispering-gallery mode (WGM) microcapillary resonator filled with a ne matic liquid crystal (LC) and a magnetic nanoparticle- coated fiber half-taper is proposed and experimentally demonstrated. In the proposed device, the tip of a fiber half-taper coated with a thin layer of magnetic nanoparticles (MNPs) moves inside the LC-filled microcapillary resonator along its axis. The input end of the fiber half-taper is connected to a pump laser source and due to the thermo-optic effect within the MNPs, the fiber tip acts as point heat source increasing the temperature of the LC material in …

Real-Time Stock Market Recommendation & Prediction Using Multi Source Data, Kalpana Konety

Dissertations

Stock investors must be cognizant of both the current price of their stock and the price at which they want to sell it in the future. This does not stop investors to monitor past price patterns and apply their knowledge to the present. ’Past performance is not an indicator of future success’, as the saying goes. To put it another way, historical stock data alone isn’t enough to forecast future stock prices. Another key factor to consider in a trading strategy is the impact of market psychology. Financial data, which is a type of multimedia data, provides a wealth of …

Measuring And Comparing Social Bias In Static And Contextual Word Embeddings, Alan Cueva Mora

Dissertations

Word embeddings have been considered one of the biggest breakthroughs of deep learning for natural language processing. They are learned numerical vector representations of words where similar words have similar representations. Contextual word embeddings are the promising second-generation of word embeddings assigning a representation to a word based on its context. This can result in different representations for the same word depending on the context (e.g. river bank and commercial bank). There is evidence of social bias (human-like implicit biases based on gender, race, and other social constructs) in word embeddings. While detecting bias in static (classical or non-contextual) word …

Hybridization Of Biologically Inspired Algorithms For Discrete Optimisation Problems, Elihu Essian-Thompson

Dissertations

In the field of Optimization Algorithms, despite the popularity of hybrid designs, not enough consideration has been given to hybridization strategies. This paper aims to raise awareness of the benefits that such a study can bring. It does this by conducting a systematic review of popular algorithms used for optimization, within the context of Combinatorial Optimization Problems. Then, a comparative analysis is performed between Hybrid and Base versions of the algorithms to demonstrate an increase in optimization performance when hybridization is employed.

Novel Hybrid Solar Nanophotonic Distillation Membrane With Photovoltaic Module For Co-Production Of Electricity And Water, Alejandro Espejo Sanchez, Nipun Goel, Todd Otanicar

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Solar energy utilization and desalination are both critical needs for large portions of the world facing energy and water challenges. Direct contact membrane distillation is an attractive thermally driven desalination technique that can easily be integrated with solar energy. Here we propose and experimentally demonstrate for the first time a hybrid direct contact membrane desalination plus photovoltaic device. The system utilizes partially transparent photovoltaic cells to produce electricity and pass thermal energy to the nanoparticle doped membrane to produce thermal energy at the membrane surface. A custom lab-scale direct contact membrane distillation setup characterizes the membranes fabricated off-sun and on-sun. …

Encapsulation Of Essential Oils In Nanocarriers For Active Food Packaging, Shubham Sharma, Lilly Mulrey, Megan Byrne, Amit Jaiswal, Swarma Jaiswal

Articles

Active packaging improves a packaging system’s effectiveness by actively integrating additional components into the packaging material or the headspace around the packaging. Consumer demand and awareness have grown enough to replace chemical agents with natural active agents. Essential oils (EOs) are extensively distributed throughout nature but at low levels and sometimes with poor recovery yields, which poses an issue with their application in food. Due to the instability of EOs when added directly into a food product, they require encapsulation before being added to a packaging matrix such as liposomes, solid-lipid nanoparticles, nano-emulsions, cyclodextrins, and nanostructured lipid nano-carriers. This article …

In-Flow Dynamics Of An Area-Difference-Energy Spring-Particle Red Blood Cell Model On Non-Uniform Grids, Brendan Walsh, Fergal Boyle

Articles

In this paper the area-difference-energy spring-particle (ADE-SP) red blood cell (RBC) structural model developed by Chen and Boyle is coupled with a lattice Boltzmann flux solver to simulate RBC dynamics. The novel ADE-SP model accounts for bending resistance due to the membrane area difference of RBCs while the lattice Boltzmann flux solver offers reduced computational runtimes through GPU parallelisation and enabling the employment of non-uniform meshes. This coupled model is used to simulate RBC dynamics and predictions are compared with existing experimental measurements. The simulations successfully predict tumbling, tank-treading, swinging and intermittent behaviour of an RBC in shear flow, and …

Modeling Isothermal Reduction Of Iron Ore Pellet Using Finite Element Analysis Method: Experiments & Validation, Amogh Meshram, Joe Govro, Ronald J. O'Malley, Seetharaman Sridhar, Yuri Korobeinikov

PSMRC Faculty Research

Iron ore pellet reduction experiments were performed with pure hydrogen (H₂) and mixtures with carbon monoxide (CO) at different ratios. For direct reduction processes that switch dynamically between reformed natural gas and hydrogen as the reductant, it is important to understand the effects of the transition on the oxide reduction kinetics to optimize the residence time of iron ore pellets in a shaft reactor. Hence, the reduction rates were studied by varying experimental parameters such as the temperature (800, 850 & 900 degrees C), reactant gas flow rate (100, 150 & 200 cm³/min), pellet size and …

Nlp@Vcu: Crop Characteristic Extraction Framework, Cora Lewis, Bridget Mcinnes, Getiria Onsongo

Summer REU Program

We developed a crop characteristic extraction framework. Starting from a custom SpaCy named entity recognition model, we added pre-trained word embeddings and a part-of-speech based entity expansion post-processing step. Then, we implemented an evaluation framework that functioned as a 5-fold cross validation wrapper for SpaCy custom training. Preliminary results showed improvement in the extraction framework after these additions.

Opportunities And Barriers Faced By Early-Career Civil Engineers Enacting Global Responsibility, Shannon Chance, Inês Direito, John Mitchell

Articles

The term ‘global responsibility’ projects a holistic sense of ethics, sustainability, and obligation. To achieve the long-term viability of human life on Earth, civil engineering must be conducted in increasingly responsible ways, and civil engineers must value and enact global responsibility in their work. Interviews conducted with nine civil engineers in London provide insight regarding engineers’ familiarity with the term, how they learned about it, what opportunities and barriers they face, and what might be done by professional and educational institutions to help them practice more responsibly. Results indicate: the term itself is novel but underlying concepts are not; continuing …

Fish And Invertebrate Use Of Restored Vs. Natural Oyster Reefs In A Shallow Temperate Latitude Estuary, Jonathan H. Grabowski, Christopher J. Baillie, Adam Baukus, Rachael Carlyle, F. Joel Fodrie, Rachel K. Gittman, A. Randall Hughes, David L. Kimbro, Juhyung Lee, Hunter S. Lenihan, Sean P. Powers, Kevin Sullivan

University Faculty and Staff Publications

Coastal marine habitats continue to be degraded, thereby compelling largescale restoration in many parts of the world. Whether restored habitats function similarly to natural habitats and fully recover lost ecosystem services is unclear. In estuaries, oyster reefs have been degraded by multiple anthropogenic activities including destructive fishing practices and reduced water quality, motivating restoration to maintain oyster fisheries and other ecosystem services, often at relatively high cost. We compared fish and invertebrate communities on recently restored (0–1 year post-restoration), older restored (3–4 years post-restoration), and natural oyster reefs to determine if and when restored reefs support functionally similar faunal communities. …

Rc Baja Independent Suspension And Chassis Design And Development, Joseph Fritz

All Undergraduate Projects

The goal of this project is to develop an RC car to compete in the MET RC Baja competition. A car will be constructed to be as lightweight, durable, and fast as possible while abiding by ROAR (Remotely Operated Auto Racers) regulations. As such, suspension, steering, chassis and drivetrain systems will need to be devised to form a complete vehicle. The chassis must provide mounting points for all other components of the vehicle and provide a rigid platform in order to create a stable vehicle. The suspension must operate smoothly, allowing for at least 1 inch of ground clearance, …

Vision And Radar Steering Reduces Agricultural Sprayer Operator Stress Without Compromising Steering Performance, Travis A. Burgers, Kelly J. Vanderwerff

Mechanical Engineering Faculty Publications

Self-propelled agricultural sprayer operators work an average of 15 h d^-1 in peak season, and steering is the task that causes the operator the most stress because of the large number of stimuli involved. Automatic guidance systems help reduce stress and fatigue for operators by allowing them to focus on tasks other than steering. Physiological signals like skin conductance (electrodermal activity, EDA) change with stress and can be used to identify stressful events. The objective of this study was to determine if using a commercially available vision and radar guidance system (VSN®, Raven Industries) reduces agricultural sprayer operators’ stress …

Data-Enabled Distribution Grid Management, Zohreh Sadat Hosseini

Electronic Theses and Dissertations

In 2020, U.S. electric utilities installed more than 94 million advanced meters, which brought the percentage of residential customers equipped with smart meters to 75%. This significant investment allows collecting extensive customer data at the distribution level, however, the data are not currently leveraged effectively to help with system operations. This dissertation aims to use the smart meters’ data to improve the grid’s reliability, stability, and controllability by solving two of the most challenging problems at the distribution level, namely distribution network phase identification and outage identification.

Distribution networks have typically been the least observable and most dynamic and locally …

Improving Quantification Of Mitral Regurgitation Through Computational Fluid Dynamics And Ex Vivo Testing, Alexandra Flowers

Electronic Theses and Dissertations

Mitral regurgitation (MR) is a prominent cardiac disease affecting more than two million people in the United States alone. In order for patients to receive proper therapy, regurgitant volume must first be quantified. As there are an array of methods to do so, the proximal isovelocity surface area (PISA) method continues to be the most accurate and clinically used method. However, there are some difficulties obtaining the necessary measurements need for this when performing transthoracic echocardiography. This study aims to evaluate and present techniques that may be used to more accurately quantify regurgitation through ex vivo testing and computational fluid …

A Water-Surface Self-Leveling Landing Platform For Small-Scale Uavs, Mbidi Santos

Electronic Theses and Dissertations

Because many of the most widely used UAVs, such as the Vertical Take-Off and Landing (VTOL), cannot land securely on sloped or fast-changing surfaces, there is a need to design better deployment and landing stations. This document proposes an approach to design a water-surface self-leveling landing platform by implementing the best concept to be used as a safe ground for UAVs to land and deploy on open waters. After conceptualizing multiple design ideas, these options were laid out in a decision matrix with four criteria: degrees of freedom, mechanical complexity, manufacturing, and cost. The chosen concept was the spherical parallel …

Classification Of Electropherograms Using Machine Learning For Parkinson’S Disease, Soroush Dehghan

Electronic Theses and Dissertations

Parkinson’s disease (PD) is a neurodegenerative movement disorder that progresses gradually over time. The onset of symptoms in people who are suffering from PD can vary from case to case, and it depends on the progression of the disease in each patient. The PD symptoms gradually develop and exacerbate the patient’s movements throughout time. An early diagnosis of PD could improve the outcomes of treatments and could potentially delay the progression of this disorder and that makes discovering a new diagnostic method valuable. In this study, I investigate the feasibility of using a machine learning (ML) approach to classify PD …

Learning Approach For Fast Approximate Matrix Factorizations, Haiyan Yu

Electronic Theses and Dissertations

Efficiently computing an (approximate) orthonormal basis and low-rank approximation for the input data X plays a crucial role in data analysis. One of the most efficient algorithms for such tasks is the randomized algorithm, which proceeds by computing a projection XA with a random projection matrix A of much smaller size, and then computing the orthonormal basis as well as low-rank factorizations of the tall matrix XA. While a random matrix A is the de facto choice, in this work, we improve upon its performance by utilizing a learning approach to find an adaptive projection matrix A from a set …

Monitoring Of State Transitions In Extreme Environment Application Materials Using Fiber Bragg Grating Sensors, Sabuj Khadka

Electronic Theses and Dissertations

By embedding both a single fiber Bragg grating (FBG) sensor and a thermocouple (TC) during the manufacturing for extreme environment applications of certain classes of materials such as metals and polymers, a novel in-situ approach was developed to precisely monitor their entire manufacturing processes. This novel monitoring technique was able to identify many characteristic points during the curing of room and high-temperature epoxies and the solidification processes of metal alloys composed of tin and bismuth which were selected in this research purely for verification purposes. Some of the characteristic points identified for the epoxies were: (i) the gel point, (ii) …

Structural And Hemodynamic Analysis Of Transcatheter Aortic Valves, Dong Qiu

Electronic Theses and Dissertations

The transcatheter aortic valve replacement (TAVR) procedure has become a well-established procedure for high, intermediate-risk, and low-risk patients. However, there is limited clinical data on the TAV's long-term durability, unlike SAV devices. Computational simulations can be an alternative way to evaluate the TAV devices. This dissertation aims to conduct structural and hemodynamic analyses on the TAV devices under different conditions using computational simulation approaches.

Initially, the impact of the bicuspid aortic valve on the TAV devices was evaluated. The result indicated that the CoreValve-like supra-annular self-expandable device was likely to have increased stress and strain on the leaflet when it …