Engineering Commons^™

The Efficacy Of Conservation Practices In Reducing Floods And Improving Water Quality, Shivendra Srivastava, Andrea D. Basche, Elbert Traylor, Tirthankar Roy

Department of Civil and Environmental Engineering: Faculty Publications

Conservation practices such as crop rotation, filter strips, and constructed wetlands are nature-based approaches intended to safeguard natural resources in agricultural landscapes. In this study, we reviewed the literature on how conservation practices, both at watershed and field scales, have been proven to subdue flood peaks, surface runoff, soil erosion, sediment transport, and nutrient loss. We classified different conservation practices based on the mode of their application (i.e., in-field, edge-of-field, and structural practices) and described what prior research efforts have concluded about the efficacy of different practices. At the field scale, practices such as reduced or no-till farming, grassed waterways, …

Robust Analog Circuit Parameter Optimization With Sampling-Efficient Reinforcement Learning, Jian Gao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Design automation of analog circuits has been a longstanding challenge in the integrated circuit field. Recently, multiple methods based on learning or optimization have demonstrated great promise in automating device sizing for analog circuits. However, they often ignore the strong susceptibility of analog circuits to process, voltage, and temperature (PVT) variations or suffer from low sampling efficiency to train algorithms. To address these critical limitations, this thesis proposes RoSE, the first Robust analog circuit parameter optimization framework with high Sampling Efficience by synergistically combining Bayesian Optimization (BO) and reinforcement learning (RL). Its core is to use the fast convergence of …

Preparing Non-Human Primates To Study Hand-Eye Coordination In Frontal Eye Fields (Fef) During Delayed Movement Task, Juliusz Cydzik

McKelvey School of Engineering Graduate Student Theses & Dissertations

ABSTRACT OF THE THESIS Preparing Non-Human Primates to Study Hand-Eye Coordination in Frontal Eye Fields (FEF) During Delayed Movement Task by Juliusz Cydzik Master of Science in Biomedical Engineering Washington University in St. Louis, 2023 Professor Lawrence Snyder, Chair Hand-eye coordination enables humans and non-human primates to use their hands and eyes to perform various tasks. We are interested in coordination at the systems level, where saccades and reaches are encoded. The parietal reach region (PRR), situated at the posterior end of the intraparietal sulcus (IPS) and overlapping portions of the medial intraparietal area (MIP) and V6a, is commonly attributed …

Evaluating The Potential Of Geopolymer Concrete As A Sustainable Alternative For Thin White-Topping Pavement, Sathvik S. Chandra, Pshtiwan Shakor, Sarwar Mohmmad, Bankole O. Awuzie, Atul K. Singh, Abishek Rauniyar, M Karakouzian

Civil and Environmental Engineering and Construction Faculty Research

Introduction:

The construction industry uses a large quantity of natural materials in the production of concrete. Although attempts to incorporate green materials in concrete began years ago, not every building uses such materials today, and roadways, particularly, still rely on unsustainable materials.

Methods:

Therefore, this study used alternative materials, including fly ash, manufactured sand aggregates, and different molarities of alkaline activators, to incorporate waste byproducts in a geopolymer concrete white-topping pavement layer. Recent developments have led to the emergence of geopolymers as distinct classes of materials. In the 1990s, fly ash-based geopolymers became more popular than other kinds, as they …

Validity Of Fitbit And Garmin Devices While Ascending And Descending Flights Of Stairs, Alan Garcia

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two popular wearable fitness device brands are Fitbit and Garmin. The validity of Fitbit and Garmin’s wrist-worn devices in measuring step counts in various settings, such as walking up and down a staircase, is unclear. PURPOSE: To determine if four devices, the Fitbit Charge 2, Fitbit Versa 2, Garmin Fēnix 5 and Garmin Vívosmart HR+ record valid measures of step count when ascending and descending flights of stairs at three different speeds. METHODS: Twenty-eight participants (n=28) were tested individually. Two devices were randomly selected to be placed on each wrist. Participants climbed up and then down one, two, and three …

Comparison Of Control Parameters For Roller Blinds, Hani Alkhatib, Philippe Lemarchand, Brian Norton, Dominic O'Sullivan

Articles

Roller blinds can reduce the heating and cooling building energy consumption required to maintain thermal comfort. The effectiveness of roller blinds is influenced by the strategies and input parameters for their control. This study is the first to identify the most effective of seven alternative control parameters to control roller blinds. It further defines the benefits from using paired control parameters to maximise energy savings and optimise occupants’ comfort. For the particular case studies and conditions examined, it is concluded that operating roller blinds using indoor air temperature as a single control parameter with rule-based controller provided, 16 %, 19 …

Dual Color Optogenetic Control For Analyzing Cardiac Function In Drosophila, Jiantao Zhu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Prolonged consumption of carbohydrate-rich diets and immobile lifestyles frequently cause metabolic disorders and obesity and, as a result, may lead to progressive heart dysfunction among broad social groups of the population. Drosophila melanogaster serves as an essential model organism in cardiovascular disease research due to conserved physiological and genomic traits shared with humans, its genetic and molecular toolbox versatility, and cost-effective maintenance. Here, we combine optogenetics and optical coherence tomography to study cardiovascular function in D. melanogaster. A new optogenetic pacing system has been developed, employing a transgenic line carrying two opsins: ChR2 and NpHR2.0. A custom-built hardware setup …

A General-Purpose Software Platform For Closed-Loop Neuromodulation, William Engelhardt

McKelvey School of Engineering Graduate Student Theses & Dissertations

Implementing closed-loop neuromodulation therapies is a challenging and expensive endeavor. It requires developing software capable of acquiring signals from a bio-signal amplifier, analysis of these signals, and initiation of precisely timed stimulation, all of which need to be accomplished in real-time with very low latency. Developing this software is difficult, as it requires a wide range of expertise ranging from interfacing with hardware to real-time signal processing. Even when successfully implementing such a system for one set of hardware, it often then only works within the laboratory that conceived it. This is because of the inherent heterogeneity in the devices …

Pathformer: Interpretable And Powerful Graph Transformer For Gene Network Analysis, Qihang Zhao, Zehao Dong, Muhan Zhang, Philip Payne, Michael Province, Carlos Cruchaga, Tianyu Zhao, Yixin Chen, Fuhai Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Understanding which gene/pathway expression profiles are related to specific disease phenotypes has been a critical active research area in Bioinformatics. Although graph neural networks (GNNs) have achieved impressive performance on various graph-based real-world applications such as recommendation systems and social network analysis, applying GNNs in gene-network-based Bioinformatical tasks is still challenging due to the effectiveness issue and lack of interpretation methods. In this paper, we propose PathFormer, an interpretable graph Transformer (i.e. GNN), to effectively analyze gene networks and discover meaningful biomarkers/pathways. PathFormer is composed of a stack of PathFormer encoder layers and two subsequent interpretation machines. The PathFormer encoder …

Memristive Behavior And Its Applications In Different Materials., Mingyang Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

The huge amount of data calculation requires the next generation non-volatile memory (NVM) technology to have the characteristics of large storage capacity and fast read/write speed. The storage and computing are separated in the traditional von Neumann architecture-based hardware platforms. The data transport between information processing and storage are causing increasing time latency, which is called von Neumann Bottleneck. Memristor, as a basic circuit component, could combine perception, storage, and computing in a single component, which has a very wide range of application prospectives. In this paper, we investigate binary oxide memristor and 2D material memristor, including their structural design …

Confined Growth Of Perovskite Stabilized By Strain Engineering, Xucheng Tao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Halide perovskite has been extensively studied for its excellent optoelectronic properties. In this project, we want to explore some range of band gap that conventional 2D materials could not have. To overcome this challenge, we aimed to produce two-dimensional (2D) perovskites with large scale which is suitable for device fabrication and improve its stability using strain engineering. To prepare such 2D perovskite, we tried 2D transformation first and then decided to use confined growth to optimize result. For strain engineering, we employed sputtered nickel as an external stressor.

So far, we have produced multilayer polycrystalline perovskites material close to atomic …

Enabling The Integration Of Sustainable Design Methodological Frameworks And Computational Life Cycle Assessment Tools Into Product Development Practice, Tejaswini Chatty

Dartmouth College Ph.D Dissertations

Environmental sustainability has gained critical importance in product development (PD) due to increased regulation, market competition, and consumer awareness, leading companies to set ambitious climate targets . To meet these goals, PD practitioners (engineers and designers) are often left to adapt their practices to reduce the impacts of the products they manufacture. Literature review and interviews with practitioners show that they highly valued using quantitative life cycle assessment (LCA) results to inform decision making.

LCA is a technique to measure the environmental impacts across various stages of a product life cycle. Existing LCA software tools, however, are designed for dedicated …

Piezoelectric And Conductive Polymer Based Flexible Devices Enabling Cardiovascular Health Sensing And Energy Harvesting, Andrew Closson

Dartmouth College Ph.D Dissertations

Piezoelectric materials show great promise for low-power wearable and implantable sensing, but their rigidity makes it challenging to integrate them with biological tissue. To address this, researchers have started exploring polymer-based functional materials that offer flexibility and are suitable for interfacing with the human body. However, these materials are still in their early stages, and a framework is necessary to illustrate how these materials, in conjunction with novel fabrication techniques and device designs, can enable the development of multi-functional sensing and energy harvesting devices.

This thesis utilizes highly scalable fabrication methods for functional polymers to build and test a flexible …

The Biological Activity Of Dual-Responsive Glycopolymers For Intracellular Codelivery Of Antigen And Lipophilic Adjuvant, Micaela Shields

Honors Theses

Subunit vaccines present themselves as an attractive alternative to traditional approaches to vaccines, which utilizes whole organisms to trigger an immune response. While these traditional approaches have proven themselves reliable within the history of vaccinations, they generally deliver subpar robust cellular-mediated immunity and pose many safety risks. Composed of proteins and /or peptides, subunit vaccines are safer and more precise alternatives to traditional approaches. However, the pharmacokinetic properties of the macromolecules that make up these vaccines hinder the subunit vaccine’s level of immunogenicity [d1] Examples of this hindrance include but are not limited to aggregation at the injection site and …

Development Of Methods To Enhance Stem Cell Derived Islet Survival, Aining Fan

McKelvey School of Engineering Graduate Student Theses & Dissertations

No abstract provided.

Meta-Analysis Of Driving Behavior Studies And Assessment Of Factors Using Structural Equation Modeling, Duong Ngoc Hai, Chu Cong Minh, Nathan Huynh

Department of Civil and Environmental Engineering: Faculty Publications

The aim of this paper is to understand the factors that influence unsafe driving practices by examining published studies that utilized the Theory of Planned Behavior (TPB) to predict driving behavior. To this end, it reviews 42 studies published up to the end of 2021 to evaluate the predictive utility of TPB by employing a meta-analysis and structural equation model. The results indicate that these studies sought to predict 20 distinct driving behaviors (e.g., drink-driving, use of cellphone while driving, aggressive driving) using the original TPB constructs and 43 additional variables. The TPB model with the three original constructs is …

Software-Defined Networking Security Techniques And The Digital Forensics Of The Sdn Control Plane, Abdullah Alshaya

LSU Doctoral Dissertations

Software-Defined Networking (SDN) is an efficient networking design that decouples the network's control plane from the data plane. When compared to the traditional network architecture, the SDN architecture shares many of the same security issues. The centralized SDN controller makes it easier to control, easier to program in real-time, and more flexible, but this comes at the cost of more security risks. An attack on the control plane layer of the SDN controller is a major security concern.

First, centralized design and the existence of a single point of failure in the control plane compromise the accessibility and availability of …

Continuous Bioprocessing: Technology For Next-Generation Biopharmaceutical Manufacturing Development Of A Python-Coded Bench-Scale Raman-Based Continuous Bioprocess Platform, Christine Urrea

KGI Theses and Dissertations

Current industrial practices for producing biopharmaceuticals include fed-batch production with batch isolation and purification. Nonproductive hold-up steps and manual offline measurements are common in batch processing which increases processing time and contributes to a high cost of production. Current market trends and cost pressures in the biopharmaceutical industry are creating a push to innovate bioprocessing platforms. Continuous bioprocessing has been considered a solution to the current limitations of batch production of biopharmaceuticals. Continuous bioprocessing involves intensifying individual processing steps by eliminating hold-up steps through a continuous operation to increase productivity, which results in advantages such as lower capital and production …

The Development Of A Primer Payload With Microparticles For Uti Pathogen Identification Using Polythymidine- Modified Lamp Primers In Droplet Lamp, Jonas Otoo

KGI Theses and Dissertations

Nucleic acid amplification tests (NAATs) are among the diagnostic tests with the highest sensitivity and specificity. However, they are more complex to develop than other diagnostic tests such as biochemical tests and lateral flow immunoassay tests. Polymerase chain reaction (PCR) is the gold standard for NAATs. PCR requires thermal cycling to achieve clonal amplification of the target pathogen DNA for diagnosis. Thermal cycling poses a challenge in the development of PCR diagnostics for point-of-care (POC) settings. Loop-mediated isothermal amplification (LAMP) offers an isothermal method for NAATs diagnostics. The advancement of the microfluidics field significantly enhances the development of LAMP diagnostics …

Modeling And Characterization Of Cmos Logic Gates Under Large Signal Rf Injection, Zahra Abedi

Electrical and Computer Engineering ETDs

This research addresses the issue of electromagnetic interference (EMI) in digital electronics, which can cause undesired behavior in active electronic components and systems. As technology advances and transistor size decreases, devices become more susceptible to EMI. In addition, as voltage is scaled down to save energy, silicon chips become more susceptible to soft errors. While there are several ways to mitigate the impact of severe EMI on digital systems, minimal electromagnetic coupling can still cause significant problems. We develop analytical models to predict device upset due to EMI. The study focuses on identifying vulnerable parameters of operation related to device …

Incentives To Learn: A Location-Based Federated Learning Model, Ryan Kilpatrick-Morrison Brown

Electrical and Computer Engineering ETDs

Federated Learning (FL) effectiveness depends, among others, on the quality and quantity of the training data and process realized at the end computing nodes. In this paper, we introduce a novel location-based federated learning model, enabled by a low-cost and fast deployable Reconfigurable Intelligent Surfaces (RIS) - based approach that allows to accurately determine the distributed computing nodes’ positions. Furthermore, in order to train a global model to support different types of smart city applications, while considering two types of servers, offering a prime and common service, respectively, under different costs, the proposed location-based FL model is complemented by an …

Machine Learning Based Prediction Models For Silicon Heterojunction Solar Cell Optimization, Rahul Jaiswal

Electrical and Computer Engineering ETDs

Silicon heterojunction solar cell of Heterojunction with Thin Intrinsic Layer (HIT) structure is a commercially available technology, and its market share will significantly increase by the next decade. With such a significant market share, any minor improvement in the device’s overall efficiency can be beneficial three folds - customer return on investment, industry revenue, and the overall carbon footprint (from manufacturing to recycling/ disposing of the device). Conventionally, device optimization for solar cells has been achieved using a hit & trial approach where multiple experiments are done to evaluate the best process conditions and device parameters. This approach has some …

Energy-Efficient Operation And Performance Optimization In Computing Systems, Nafis Irtija

Electrical and Computer Engineering ETDs

In the modern world, an expansive range of computing systems are being used, and in all of these systems, energy efficiency and performance optimization are of utmost significance. But performance optimization means different things for different computing systems. Because of their difference in nature, computing systems have different requirements for efficiency and optimization. Distributed systems such as smart-grid systems, edge-computing environments, and blockchain systems focus on the behavior of the agents. Thus, the application of network economics principles, such as Game Theory and Contract Theory, can improve the operation of these systems in a multitude of ways. On the other …

Vi Energy-Efficient Memristor-Based Neuromorphic Computing Circuits And Systems For Radiation Detection Applications, Jorge Iván Canales Verdial

Electrical and Computer Engineering ETDs

Radionuclide spectroscopic sensor data is analyzed with minimal power consumption through the use of neuromorphic computing architectures. Memristor crossbars are harnessed as the computational substrate in this non-conventional computing platform and integrated with CMOS-based neurons to mimic the computational dynamics observed in the mammalian brain’s visual cortex. Functional prototypes using spiking sparse locally competitive approximations are presented. The architectures are evaluated for classification accuracy and energy efficiency. The proposed systems achieve a 90% true positive accuracy with a high-resolution detector and 86% with a low-resolution detector.

Synthesis And Characterization Of Sodium Cathode Materials, He Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

As sodium batteries hold great promise as a next-generation energy storage device to replace lithium batteries, the development of sodium battery materials has become increasingly urgent. The current study aims to investigate two potential sodium-ion battery cathode materials, Sodium Vanadium Phosphate, and Sodium Manganese Hexacyanoferrate, optimize the experimental procedures, conduct a systematic analysis of material properties and characterization, and ultimately determine the ideal synthesis conditions for these materials.

In the first part of the study, we focused on optimizing the synthesis of Sodium Vanadium Phosphate. By investigating various synthesis conditions, such as annealing temperature, pressure, ascorbic acid content, and material …

Strength As A Function Of Liquid Water Content In Different Snow Types - Results From Field Experiments Using A Blade Hardness Gauge, Mikael Schlumpf

Civil Engineering ETDs

The rapid weakening of snow layers that locally accumulate infiltrating liquid water is a well-known mechanism for wet slab avalanche formation. To quantify this process and improve the prediction of these destructive avalanches, a blade hardness gauge (BHG, a.k.a thin blade penetrometer) and SLF snow sensor were used to take 349 targeted paired measurements of strength and LWC, respectively, in the snow above 19 artificially wetted capillary barriers. Using a multiple regression analysis, we develop an expression for the blade hardness of manually wetted snow as a function of LWC, crystal form, and blade hardness prior to wetting. To understand …

Equity In Transportation: Data Driven Analysis Of Transportation Services And Infrastructures, Javad Jomehpour Chahar Aman

Civil and Environmental Engineering Theses and Dissertations

Achieving equity in transportation is an ongoing challenge, as transportation options still vary tremendously when it comes to marginalized populations. This dissertation addresses this challenge by conducting a comprehensive review of existing transportation equity literature and identifying two critical gaps: the lack of data-driven approaches to studying spatial mismatch between transportation supply and demand, and limited information on women's perceptions and expectations towards emerging transportation services.

Chapter two introduces the concept of transportation "deserts," specifically transit deserts and walking deserts, and develops data-driven frameworks to identify and investigate neighborhoods with limited transportation service supply but high demand. The frameworks compare …

A Mechanics-Based Analytical Solution For Restrained Beams With Application To Progressive Collapse Behavior, Leven Deputy

Civil and Environmental Engineering Theses and Dissertations

This dissertation presents an axially restrained beam (ARB) model that incorporates axial-flexural interaction throughout the entire static load-deflection curve: the elastic material range, the plastic, flexural dominant range, the range beyond plastic flexure with increasing catenary effect, and the full catenary range. Energy methods are applied to static load-deflection curves to determine dynamic load-deflection relationships. Specifically, this dissertation considers the two conditions; Pinned-Pinned-Pinned (PPP) which has no flexural resistance at the boundaries, and Fixed-Fixed-Fixed FFF (also Pinned-Fixed-Pinned, PFP) condition which provides the beam with flexural resistance at the boundaries equal to flexural capacity of the beam. Behavior is explained analytically …

Transport Mechanisms In Electrochemical Immunoassay Biosensors With Applications To Sarscov-2 Neutralizing Antibody Detection, Mohammad Karim Dehghan Manshadi

Mechanical Engineering Research Theses and Dissertations

Biosensors are used in diverse applications spanning from clinical diagnosis and drug discovery to environmental and safety monitoring. Among different types of biosensors, electrochemical ones have demonstrated high sensitivity, short detection time, and selectivity with a low cost, and have been widely used to detect various diseases. In this thesis, we have introduced an inexpensive, rapid, sensitive, and quantifiable impedance-based immunosensors to evaluate SARS-CoV-2 neutralizing antibody (NAb), which shows the real protective immunity against COVID-19. We demonstrated that our device enabled assessment of NAb in a physiological buffer with conductivity equivalent to that of blood plasma. This technique can be …

Electromagnetically Actuated Modular Robots With Controlled Self-Assembly And On-Demand Disassembly, Anuruddha Bhattacharjee

Mechanical Engineering Research Theses and Dissertations

Modular reconfigurable robots, with on-demand assembly and disassembly, offer the possibility of mesoscale (milli- and microscale) manufacturing. However, most of the existing modular robotic platforms currently being designed and functionalized rely on complex actuation and assembly mechanisms and so lack further scalability and transformability required for mesoscale applications. Therefore, this dissertation seeks to develop a novel scalable modular robotic platform with controlled self-assembly, disassembly, and reconfiguration techniques using an external electromagnetic field. While current cutting-edge research in this area uses a single magnet to move one module at a time into the target position, this dissertation explores processes to move …