Engineering Commons^™

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

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

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

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

Institute for Sustainable Manufacturing Faculty Publications

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

Spin-Coated High Mobility Moo3 Thin Film For Designing Highly Efficient Lead-Free Perovskite Solar Cells, M. A. Islam, Ihsan Ahmad Siddiquee, Y. A. Wahab, S. F.W. Hatta, Jakaria Mahdi Imam, Foo Wah Low, Aziz Ahamed, Mohammad Nur E. Alam

Research outputs 2022 to 2026

Among the thin film-photovoltaics, perovskite solar cells (PSCs) are one of the most developing topics of research in recent times. Research records reveal that around 26 % efficiency in PSCs has already been achieved so far. However, the commercialization of those PSCs is hindered due to the toxicity of lead (Pb), and the instability of organic cations as well as structural volatility. Several inorganic materials including inorganic hole transport layer (HTL) have recently been proposed and developed to reduce the organic part in the device structure. We fabricate MoO3 thin film materials and conduct a detailed study to realize the …

Advance On Rock-Breaking Cutter Steels: A Review Of Characteristics, Failure Modes, Molding Processes And Strengthening Technology, Ying Jiang, Bai Xin Dong, Jun Fan, Feng Qiu, Hong Yu Yang, Shi Li Shu, Fang Chang, Qi Chuan Jiang, Lai Chang Zhang

Research outputs 2022 to 2026

Rock breaking has always been a challenging problem that must be solved in projects such as excavating mountains, drilling wells, and constructing railways. Among the rock-breaking cutter steels, AISI H13 steel and wear-resistant high manganese steel have become the best choices. From the characteristics and failure modes of the two, rock-breaking cutter steels should simultaneously have high strength, high toughness and high wear resistance to avoid short-term fracture/damage and cost increase. Analyzing the problems existing in the molding process of rock-breaking cutter steels such as die casting, forging, and hot stamping, traditional strengthening technologies such as alloying optimization, heat treatment, …

Numerical Modelling And Performance Investigation Of Inorganic Copper-Tin-Sulfide (Cts) Based Perovskite Solar Cell With Scaps-1d, Ayesha Siddique, Md Nurul Islam, Hironmoy Karmaker, A. K.M. Asif Iqbal, Abdullah Al Mazed Khan, Md Aminul Islam, Barun Kumar Das

Research outputs 2022 to 2026

Perovskite solar cells (PSCs) are a favorable option for the upcoming generation of photovoltaic systems due to their simplicity and high energy conversion efficiency. The third iteration of thin-film solar cells including copper-tin-sulphide (CTS) is easily accessible on Earth, possesses excellent optoelectrical properties, and does not include any harmful substances, making it environmentally sustainable. Using the solar cell capacitance simulator (SCAPS), this study examines the performance of a PSC based on copper oxide (Cu2O) and zinc selenide (ZnSe). The study investigates the factors that influence the performance of CTS-based SCs, such as absorber layer thickness, absorber defect density, interface defect …

Preparation, Reaction Mechanism And Microwave-Absorbing Application Of Functional Transition Metal Carbide/Nitride Ceramic Materials, Zhengbo Xu, Shu Qing Kou, Bai Xin Dong, Xinmiao Zhong, Hongyu Yang, Lin Liu, Ruifen Guo, Shi Li Shu, Feng Qiu, Lai Chang Zhang

Research outputs 2022 to 2026

The explosive growth of wireless communications and electronic devices has brought electromagnetic radiation's harmfulness and hidden trouble to light, which has a major impact on electrical equipment's ability to function normally. MXene, a material with favorable features like conductivity, a unique two-dimensional multiple-layer structure and abundant surface functional groups, has made it a viable contender for high-performance microwave-absorbers. This article introduces the synthesis strategy of MXene/MXene-based materials and their parent phase MAX, comprehensively summarizes and analyzes the current progress in the study on the microwave-absorbing properties of MXene/MXene-based materials, analyzes the main problems and bottlenecks. Future research directions for MXene …

Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures Phase 2, Andrea Calabrese, Pitiporn Asvapathanagul, Nisarg N. Patel, Nanubala Dhruvan, Austin Adams, Michael Hernandez, Douglas S. Lopez-Cruz

Mineta Transportation Institute

Concrete is a critical component of so much of the modern construction industry. This material, well known for its versatility, robustness, longevity, and strength, is well-suited for a wide range of structural applications. Nonetheless, the widespread occurrence of cracks in concrete structures, primarily attributed to its limited tensile strength, shrinkage, and overstain, imposes a considerable economic and environmental challenge when it comes to retrofitting these fissures. This study tackles this problem by harnessing bacteria tolerant to high alkaline conditions to enable Microbially Induced Calcium Carbonate Precipitation (MICP) for the self-repair of concrete. This is achieved through an external application method, …

Battery Management System Development For Electric Vehicles And Fast Charging Infrastructure Improvement, Yu Yang, Hen-Geul Yeh, Cesar Ortiz

Mineta Transportation Institute

The electric vehicle (EV) has become increasingly popular due to its being zero-emission. However, a significant challenge faced by EV drivers is the range anxiety associated with battery usage. Addressing this concern, this project develops a more efficient battery management system (BMS) for electric vehicles based on a real-time, state-of-charge (SOC) estimation. The proposed study delivers three modules: (1) a new equivalent circuit model (ECM) for lithium-ion batteries, (2) a new SOC estimator based on the moving horizon method, and (3) an on-board FPGA implementation of the classical Coulomb counting method for SOC estimation. The research team extends the traditional …

Prediction Of Mechanical And Electrical Properties Of Carbon Fibre-Reinforced Self-Sensing Cementitious Composites, Zehao Kang, Farhad Aslani, Baoguo Han

Research outputs 2022 to 2026

The transmission of signal values in self-sensing concrete allows us to precisely locate damaged structures and prevent disasters. Currently, there are over ten functional materials used in self-sensing concrete applications. Carbon fibre (CF) is a well-known functional material that has been extensively studied for its reproducibility and accuracy in self-sensing concrete experiments. In contrast, this study is based on finite element modelling to rapidly predict the impact of the functional filler material, CF, on concrete performance. This paper simulates the mechanical and piezoresistive properties of concrete with unsized and desized short-cut CFs at lengths of 3, 6, and 12 mm. …

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

Electrical and Computer Engineering Faculty Research & Creative Works

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

A Study Of Directionality Effects In Three-Beam Coaxial Titanium Wire-Based Laser Metal Deposition, Remy Mathenia, Braden Mclain, Todd Sparks, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Coaxial wire-based laser metal deposition is a versatile and efficient additive process that can achieve a high deposition rate in the manufacturing of complex structures. In this paper, a three-beam coaxial wire system is studied, with particular attention given to the effects of the deposition direction and laser beam orientation on the resulting bead geometry symmetry. With the three-beam laser delivery, the laser spot pattern is not always symmetric with respect to the deposition direction. Single titanium beads are deposited in different directions and at varying deposition rates, and the bead profile is quantitatively scored for multiple symmetry measures. Through …

Analytical And Fem Models For Thermal Analysis And Residual Stresses Using Wire Arc-Based Welding And Additive Manufacturing Of Sus304, Muhammad Arif Mahmood, Usman Tariq, Mihai Oane, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Austenitic stainless steel, also known as SUS304, has a wide industrial application. The resultant residual stresses and deformation due to arc welding play a critical role in an in-service SUS04 part failure. Various experimental studies have been presented to predict residual stresses and part deformation. However, these techniques are expensive and time-consuming owing to the trial-and-error approach, limiting their application to industrial applications. Based on the emergent need, this study introduces two simulation models based on analytical and FEM techniques for thermal distribution and residual stress estimation. The experimentally calibrated models results have been implemented for SUS304 multi-pass arc welding. …

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

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

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

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

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

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

An Experimental Study On Mixed Hydrocarbon Gas On Transport Through Subsurface And Atmospheric Interfaces With Application To Natural Gas Pipline Leak Dection And Quantification, Richard Kolodziej

Civil and Environmental Engineering Theses and Dissertations

Natural gas (NG) production and usage as a fuel source have surged in recent years, becoming a critical component of the global energy system and requiring extensive belowground pipeline infrastructure. Leaks in belowground pipelines release fugitive methane (CH₄) emissions, posing significant environmental, safety, and economic risks. Effective leak detection and quantification (LDAQ) methods are essential for identifying and measuring leaks to enable timely repairs and accurately address these threats. However, few studies have characterized the effectiveness of current and advanced LDAQ survey methods for belowground NG pipelines, with existing work often limited to technology-centric evaluations or studies of …

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

Chemical and Materials Engineering Faculty Publications

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

Explainable Artificial Intelligence: Methods And Evaluation, Gayane Grigoryan

Engineering Management & Systems Engineering Theses & Dissertations

A wide array of techniques within explainable artificial intelligence (XAI) have been developed to measure the importance of features in machine learning models. A notable portion of these methods draws upon principles of cooperative game theory (CGT), with the Shapley value emerging as a widely used solution concept. Despite the rising prominence of the Shapley value, other promising solutions from cooperative game theory—such as the Nucleolus, Banzhaf power index, Shapley-Shubik power index, and solutions to conflicting claims problems—have been comparatively overlooked, even though they hold significant potential. In this dissertation, multiple XAI methods based on these other CGT solutions are …

Safe And Efficient Operation Of Mobile Robots In Indoor Environments: A User-Centric Shared Control System With High-Level Navigation Capabilities, Ahmet Saglam

Electrical & Computer Engineering Theses & Dissertations

Hospitalization and isolation can be a traumatic experience for immunocompromised children, especially because they are separated from their families and friends. Social robots have been proposed as a way to improve the quality of care for children hospitalized in isolation by providing alternative means of social interaction and support. Remote control of such robots in a hospital setting, particularly where safety is a major concern, can be a daunting task for young patients.

This dissertation introduces a multilevel shared control system for mobile robots, specifically companion robots in hospital-like indoor spaces. The system integrates user inputs with algorithmic semi-autonomous control …

Hydrologic Modeling Of The Lower Chesapeake Bay Watershed Using Hecc-Hms With Implications For Future Coupled Coastal Modeling, Christopher Leonard Frost

Civil & Environmental Engineering Theses & Dissertations

This study explores the hydrological methodology for modeling a coastal watershed basin using the US Army Corps of Engineers hydrologic software, HEC-HMS with an objective of being able to create riverine boundary conditions that could be applied to a coupled compound flood model. Compound flooding is defined as high water inundation event that occurs due to the simultaneous occurrence of multiple flooding drivers. The Atlantic Seaboard and the Gulf of Mexico regions of the United States account for most of the compound events observed in the United States with a higher occurrence caused by hurricanes from July to November. In …

Zero Dynamics Attacks On Unknown Bilinear Systems: Vulnerability And Detection, Mohammad Aminul Haq

Electrical & Computer Engineering Theses & Dissertations

Critical infrastructure requires a safe and secure operating environment because of its significant impact on society. Its large-scale size and distributed sensors and actuators make it vulnerable to cyber-physical attacks. A zero dynamics attack is a type of cyber-physical attack where an adversary keeps the output of the target constant (classically zero), while forcing some of the internal states to deviate from their nominal values. Most of the existing work in the literature assumes the system dynamics are linear and available to an adversary. The first goal of this dissertation is to show that an adversary can successfully execute a …

A Kinematic Analysis Of The Shoulder During The Volleyball Attack Using Euler And Helical Axis Methods, Victoria Jolliff

Biomedical Engineering Theses & Dissertations

The shoulder is a complex joint with a wide range of motion, including flexion, extension, abduction, adduction, and internal and external rotation. In volleyball, repetitive overhand movements can cause shoulder overuse injuries. The primary offensive move, the attack, involves the approach, arm cocking, arm acceleration, and follow-through phases. Motion capture analysis and techniques like calculating Euler angles and rotation about a mean helical axis can evaluate shoulder movements. This study aimed to calculate shoulder movements during each phase of the volleyball attack using the Euler angle YXY sequence and the helical axis method. Different attack types, such as cross-court and …

Development Of A Conceptual Framework For Complex System Governance (Csg) Performance Measurement, James Hartwell Rutherford

Engineering Management & Systems Engineering Theses & Dissertations

Within the Complex System Governance (CSG) paradigm, system performance is regulated by nine metasystem governance functions, which provide control, communication, coordination, and integration. However, CSG has lacked a fully developed model or language to richly articulate system performance at a conceptual level. The purpose of this research was to develop a systems theory-based conceptual framework to measure the performance of CSG metasystem governance using an inductive research design.

Although ‘good performance’ may seem like an obvious idea, the current literature on performance measurement across many disciplines and contexts contains vastly inconsistent uses of the word ‘performance.’ Both researchers and practitioners …

Mesostructure Reconstruction Of Prepreg Platelet Molded Composite With Artificial Intelligence, Richard Larson

Mechanical & Aerospace Engineering Theses & Dissertations

Prepreg platelet molded composites (PPMC) are long, discontinuous fiber reinforced polymer materials. PPMC are an important subcategory of composite materials as they are processible into geometrically complex structures and can be produced via high-throughput manufacturing processes, however they have higher stiffness and strength as compared to traditional discontinuous fiber reinforced polymers. However, there is inherent randomness in the structure of PPMCs and as such, PPMC parts frequently require per part testing that is cost prohibitive.

Herein, a method using artificial intelligence is proposed as a more cost-effective method of inspecting PPMC parts. Different artificial intelligence (AI) architectures are explored to …

Ductape: A Steady-State, Axisymmetric Ducted Fan Analysis Code Designed For Gradient-Based Optimization, Judd Mehr, Andrew Ning

Faculty Publications

Electric ducted fans have become an intriguing option for the propulsion systems of clean, quiet advanced air mobility technologies due to their potential benefits in both aerodynamic efficiency and reduced noise profiles compared to open rotor systems. Exploration of conceptual electric ducted fan design in the context of novel, and often complex, applications may be greatly aided by the use of optimization techniques. Specifically, gradient-based optimization lends itself to the exploration of large, complex, multi-disciplinary systems due to its inherent scalability. Despite ducted fans/propellers having been relatively well studied for the last century, modern, gradient-based, optimization-ready analysis tools for ducted …

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

Kentucky Transportation Center Research Report

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

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

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

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

Teaching Learning Newsletter Vol 4 Issue 1, Sastra Deemed To Be University

TLC Newsletter

No abstract provided.

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

Electrical Engineering and Computer Science Faculty Publications and Presentations

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

Jme 4110: Better Beach Wagon, Jalen Rhodes, Joshua Peters, Seth Peters, Jevonn Lewis-Harris

Washington University / UMSL Mechanical Engineering Design Project JME 4110

This project aims to add to a current beach wagon and improve effective movement through sand and concrete. Some beach wagons out in the market make it incredibly difficult to navigate through sand, often requiring more effort to push or pull. Some beach wagons solve these issues, such as electric beach wagons and their use of balloon tires; however, they are typically expensive, costing up to $2500.00. With Visionary Solutions’ design, the beach wagon will be able to move smoothly through both terrains (concrete and sand) and will be inexpensive to produce. The materials design includes polylactic acid (PLA) 3D …

Jme 4110: Stand-Up Pedicure Final Report, Heather Burt, Brian Hinkle, Jonathon Riggle, Anna Domingo Garcia

Washington University / UMSL Mechanical Engineering Design Project JME 4110

This project focuses on designing a pedicure device specifically for individuals who struggle with bending down to cut their toenails. While many people may not give this task a second thought, for some, it is a daily challenge. The goal is to create a device that allows users to safely and comfortably cut their toenails without needing to bend down or visit a nail salon, saving them time, effort, and money. This innovative design will cater to those with physical limitations, enabling them to maintain their nail care independently.