Engineering Commons^™

An Analytical, Numerical, And Experimental Study Of Automated Damage Assessment For Concrete Structures, Sanggoo Kang

Civil Engineering Dissertations - Archive

This dissertation presents the automated damage assessment studies for concrete structure. Three major studies are performed to: 1) understand the theoretical wave scattering model to evaluate the internal vertical crack, 2) to validate the theoretical wave scattering model through FE simulations with experimental measurements, and 3) to advance practical automated crack evaluation (ACE) system for vertical crack and delamination detection. Firstly, singular integral solutions are studied to investigate scattering of Rayleigh waves by subsurface cracks. Defining a wave scattering model by objects, such as cracks, still can be quite a challenge. The model’s analytical solution uses five different numerical integration …

Testing Methods Of Surficial Sinkhole Identification Using Remotely Sensed Data, Dane P. Brophy

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Nearly a quarter of all people rely on karst aquifers for drinking water. In the United States, the Safe Water Drinking Act requires a complete assessment of public water systems' vulnerabilities to contamination. As part of that assessment, watershed boundaries must be delineated, while recharge and supply locations identified. In the context of karst aquifers, surficial karst features, such as sinkholes, can act as a point source of direct recharge to karst aquifers and create vulnerabilities to critical drinking water sources. Historical methods of locating these features are inefficient and depend on basic field investigations, resulting in a clear need …

Direct Drive Solar Panel Control Circuit, Marcorios Bekheit

Physics

A control circuit is built for insulated solar electric cookers (ISEC). Power delivery and temperature safety are the focus. Using a maximum power point tracking (MPPT) algorithm, Arduino Nano, voltage and current sensors, and a buck converter, the solar panel’s output power was maximized for a direct load heat resistor with 3.5Ω for a range of solar intensities. Using a resistance temperature detector, a temperature sensor is built for safety shutoff.

Understanding Process Controls On Flow Duration Curves Through A Novel Framework, Saba Ghotbi

Electronic Theses and Dissertations, 2020-2023

Flow duration curve (FDC) is a hydrologically representation of the statistical distribution of daily streamflows. For a long time, hydrologists have sought deeper understanding of the process controls on the shape of FDC, which has been a challenge due to contrasting processes controlling the fast flow and slow flow components of streamflow and their interactions. This dissertation addresses the challenge by outlining a novel framework to explore the physical controls on FDC. The framework involves separating streamflow into fast flow and slow flow and studying their duration curves separately then combining them statistically to obtain FDC. Initially, the potential of …

Topological Changes In The Functional Brain Networks Induced By Isometric Force Exertions Using A Graph Theoretical Approach: An Eeg-Based Neuroergonomics Study, Lina Ismail

Electronic Theses and Dissertations, 2020-2023

Neuroergonomics, the application of neuroscience to human factors and ergonomics, is an emerging science focusing on the human brain concerning performance at work and in everyday settings. The advent of portable neurophysiological methods, including electroencephalography (EEG), has enabled measurements of real-time brain activity during physical tasks without restricting body movements. However, the EEG signatures of different physical exertion activity levels that involve the musculoskeletal system in everyday settings remain poorly understood. Furthermore, the assessment of functional connectivity among different brain regions during different force exertion levels remains unclear. One approach to investigating the brain connectome is to model the underlying …

Field Demonstration Of Gpr And Uav Technologies For Evaluation Of Two Us 75/77 Bridges, Sepehr Pashoutani, Jinying Zhu, Chungwook Sim, Ji-Yong Lee

Nebraska Department of Transportation: Research Reports

Two Nebraska bridges with asphalt overlay were selected for nondestructive testing and evaluation (NDT/NDE). Three NDT techniques were conducted on these two bridges, including Ground Penetrating Radar (GPR), Half-Cell Potential (HCP) and Unmanned Aerial Vehicle (UAV) imaging. NDT data were collected during three construction stages of the bridges: (1) before repair on existing asphalt overlay; (2) on bare concrete after asphalt removal; (3) and after repairing delaminated concrete.

A machine learning technique, autoencoder, was used to build quantitative relationships between different NDT datasets. On bare concrete, the GPR amplitude and HCP voltage show a strong linear relationship. Then a threshold …

Settling Of Spherical Particles In High Viscosity Friction Reducer Fracture Fluids, Ghith Biheri, Abdulmohsin Imqam

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Investigating the key factors that impact fluid rheology and proppant static settling velocity in high viscosity friction reducers (HVFRs) is a critical aspect for successful proppant transport in hydraulic fracture treatment. In this study, the rheological properties of HVFRs were tested at various temperature ranges (i.e., 25, 50, 75, and 100◦C) and different HVFR concentrations (i.e., 1, 2, 4, and 8 gpt). Three sizes of spherical particle diameters (i.e., 2, 4, and 6 mm) were selected to measure the static settling velocity. The fracture fluid was tested in two fracture models: an unconfined glass model and a confined rectangular model …

Characterization Of Msw And Plastic Waste Volume Estimation During Covid-19 Pandemic, Sehneela Sara Aurpa

Civil Engineering Theses - Archive

COVID-19 has appeared and shook all aspects of our life. Starting from panic buying prior lockdown to the availability of vaccine, the whole world has gone through a pandemic situation which bounded people to live a life that never seemed normal before. Lockdown and risk of spreading disease forced people to stay at home and generate more waste, especially plastic waste. The effect on municipal solid waste characteristics due to this shift in the way of living is assessed in this study. In this study, municipal solid waste was collected from the working face of Irving Hunter Ferrell landfill. Waste …

Feasibility Assessment Of Production Of Liquid Organic Fertilizer (Lof) From Food Waste For Sustainable Waste Management, Shadman Sakib

Civil Engineering Theses - Archive

The increasing volume of food waste is responsible for the generation of potent greenhouse gases and is resulting in the wastage of valuable resources. In all regions of the world, the percentage of food waste in municipal solid waste is greater. Due to the lack of waste segregation at collection points and modern waste disposal methods in developing countries, organic waste is piling up in the dumpsites and landfills. Besides due to poor harvest and post-harvest procedures and inefficient supply chain, almost 55% of the cultivated crops do not even reach the consumers and get wasted. On the other hand, …

A Comprehensive Framework To Mitigate Surficial Slope Failures, Burak Boluk

Civil Engineering Dissertations - Archive

Each year, numerous highway and dam slopes that are built with high plasticity clays experience shallow slope failures. Besides the high maintenance and repair costs, these failures negatively impact the public life by interrupting the traffic flow and causing serious safety hazards. The development of desiccation cracks due to weathering cycles deteriorates hydro-mechanical properties of soil, increases water infiltration, and ultimately results in surficial slope failure. Several slope rehabilitation methods have been developed to stabilize clayey soil slope sections affected by surficial failures. Lime stabilization is an effective treatment method that generally reduces the swell-shrink potential of expansive soil and …

Nonlinear And Quantum Optics In Few-Mode-Fibers, Afshin Shamsshooli

Electrical Engineering Dissertations - Archive

In the absence of quantum repeaters, fiber loss sets the hard limit on secure quantum communication rate. Single-photon source rate decays exponentially with the length of fiber. The only way to scale the rate up is by increasing the number of modes over which the single-photon or entangled states are transmitted, for subsequent use in. quantum communication, computing, or information processing. Entanglement in multiple degrees of freedom, e.g., in polarization, frequency, time-bin, and spatial modes has a potential for carrying larger amounts of quantum information. In this project, we explore spatial modes in the few-mode fiber for generation and processing …

Evaluating The Thermal Performance Of Topology Optimized Low-Cost 3d Printed Heat Sink Made Of Copper, Bilal Taha

Mechanical and Aerospace Engineering Theses - Archive

The performance of a heat sink is highly dependent on the overall surface area available for heat transfer. Designing heat sinks with greater surface areas meant bigger size, weight, and volume of heat-exchanger thus making it unfeasible to produce. Design and manufacture of compact-sized heat sinks is a difficult task, as it would require the use of complex surface modeling and complex surface cutting. But with the advent of 3D printing technology, it has become easier to manufacture heat sinks having complex designs producing larger surface areas as they add material layer by layer rather than cutting it away. The …

Investigation On Microstructure And Mechanical Properties Of Porous Structures Processed By Laser Powder Bed Fusion, Samarth Ramachandra

Mechanical and Aerospace Engineering Theses - Archive

Inconel 718 (i.e., IN718) is a prominent nickel-based, precipitation-hardening superalloy which exhibits exceptionally stable mechanical and corrosion resistant properties, even at temperature range of 650ºC to 700ºC, making it suitable for a wide range of applications such as aerospace, nuclear reactors, tooling, turbines, oil and gas applications. The high toughness and work hardening offered by this superalloy, however, greatly limits the choice of machinability. The presence of low levels of aluminum permits good weldability which further allows the use of laser-based additive manufacturing (AM) to efficiently fabricate IN718 parts without the limitations associated with conventional manufacturing methods. Thanks to AM …

Investigation Of The Microstructural And Mechanical Properties Of Selectively Laser Melted In718 Overhangs Fabricated Without Support Structures, Manjunath Hanumantha

Mechanical and Aerospace Engineering Theses - Archive

Additive manufacturing is a new manufacturing technology that allows for extreme design freedom as well as the simultaneous production of many parts with high complexities. IN718 is a high-strength, corrosion-resistant super alloy of nickel and chromium. It is ideal for high-end applications such as rocket nozzles and turbines because it can handle exceptionally high pressure and heat. Because of its high stiffness qualities, conventional manufacturing of complex IN718 geometries is challenging. Various fabrication techniques have been developed, and this study focuses on selective laser melting (SLM) because of its potential to produce near-perfect parts at a low cost when working …

Structural Optimization And Reliability Assessment Of Heterogeneous 3d Ic Packages And Analysis Of Rheological Properties Of Particle Based Thermal Interface Materials, Mehzabeen Binte Kabir

Mechanical and Aerospace Engineering Theses - Archive

As computing and communication devices are converging with improved functionally, denser, and finer pitch which creates complexity of circuit interconnections for 2-D devices becomes a limitation for overall performance and drives up power dissipation [1]. Thus the ordinary 2-D structures of IC packages cannot address those demands where 3-D through-silicon via (TSV) is the key to 3-D IC integration and stacking of chips, is emerging now as a powerful tool to converge the needs of integrated circuit (IC) packages. In 3D TSV the chips are stacked on top of another so heat trapped in a small region which is difficult …

Pavement Temperature Response To Cold Fronts: A Model Column Study In A Freezer Box, Taryn Dilorenzo

Civil Engineering Theses - Archive

The correlation of meteorological data and pavement conditions is crucial for winter pavement maintenance, this is the main reason that it is so important to understand in what ways pavement responds to cold fronts as well as when the formation of ice on a pavement surface can be expected. The pavement surface and its underlying subsurface layers combine to create a system with the behavior of the surface being influenced by both the air temperature above it, as well as the temperature and thermodynamic processes occurring in the sublayers below it. Both the pavement surface as well as the sublayers …

Flexural Strengthening Of Two-Way Slabs Using Cfrp External Laminates, Shams Abbas Naqvi

Civil Engineering Theses - Archive

Deterioration of reinforced concrete structures with time is a common phenomenon, which often leads to reduction in the load carrying capacity. To meet the coding requirements, strengthening of these structures is of utmost importance. Composite materials, such as Carbon Fiber Reinforced Polymers (CFRP), have shown effective results in external strengthening of these structures. However, premature delamination of CFRPs can decrease their efficiency. Recently, pre-saturated CFRP (PS-CFRP), a new type of CFRP pre-impregnated with epoxy resin, was introduced. Previous research has shown that PS-CFRP has shown improved results as compared to regular CFRP (R-CFRP) for strengthening beams and columns. However, no …

Development Of Rf-Mems Based Passive Wireless Respiratory Monitoring Systems, Sina Moradian

Electronic Theses and Dissertations, 2020-2023

This dissertation explores the application of high frequency, low loss, high quality factor thin-film piezoelectric MEMS resonators as passive wireless respiratory monitoring sensors. In this work we build on advances in RF MEMS technology and wearables to develop a respiratory monitoring system capable of measuring respiration without any on-board circuitry and battery First, a wireless MEMS-based respiration sensor that operates without a battery or any on-board circuitry is presented. The sensing system is made up two major components, the wireless sensor and a base transceiver and computational unit. The sensor is only made of up of two RF-MEMS resonators and …

Bidding Enabled Inventory Redistribution In A Retail Network, Hafsa Binte Mohsin

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This research aspires to develop a systematic approach to minimize the demand and supply gap of products and product expiration in a feasible way. Inventory replenishment policy, uncertain customer demand, and forecast inaccuracy are some of the reasons that create imbalanced stocks in the outlets. Lateral transshipment or redistribution, donation, and promotion have been discussed in the existing literature separately as ways to balance and utilize inventory. Redistribution needs to account for extra transportation costs due to stock transfer. Existing literature on redistribution fails to address products’ physical attributes, valuation of products as a function of time, and constraint on …

Quantifying The Benefits Of A Collaborative Supply Chain Network Using A Discrete-Time Vehicle Routing Model, Matthew Walters

Industrial Engineering Undergraduate Honors Theses

The transportation industry contributed around one trillion dollars to the economy in 2016 accounting for 8.9% percent of the GDP. In 2017, it was responsible for 1.5 billion tons of CO₂ emissions. With the American Trucking agency predicting a 35% growth in the trucking industry between 2016 and 2027, there are rising concerns about the impact the trucking industry will have on the economy and the environment. The trucking industry is also very inefficient with many trucks driving with empty loads or with less than full capacity loads. There is potential to save billions of dollars and cut back …

Performance Enhancement Of Time Delay And Convolutional Neural Networks Employing Sparse Representation In The Transform Domains, Masoumeh Kalantari Khandani

Electronic Theses and Dissertations, 2020-2023

Deep neural networks are quickly advancing and increasingly used in many applications; however, these networks are often extremely large and require computing and storage power beyond what is available in most embedded and sensor devices. For example, IoT (Internet of Things) devices lack powerful processors or graphical processing units (GPUs) that are commonly used in deep networks. Given the very large-scale deployment of such low power devices, it is desirable to design methods for efficient reduction of computational needs of neural networks. This can be done by reducing input data size or network sizes. Expectedly, such reduction comes at the …

Investigating Topologic And Geometric Properties Of Synthetic And Natural River Networks Under Changing Climate, Shiblu Sarker

Electronic Theses and Dissertations, 2020-2023

River networks are important landscape features that collect and transport water, sediment and nutrients from regions of higher elevation to lower elevations. These networks have been studied for several decades from a range of geomorphological and hydrological perspectives. Investigating the geometric and topological properties of river networks is important for developing predictive models describing the network dynamics under changing climate as well as for quantifying the physical processes operating upon them. Although these networks have been characterized for a wide range of geomorphic properties, topological properties, and in particular, spectral properties of river networks received limited attention. In this dissertation, …

Contributing To Engineering Colleges Students' Development Through Out-Of-Class Involvement: A Survey Of Chinese Private Colleges' Engineering Students, Wanlu Li

Education (PhD) Dissertations

The purpose of this study was to investigate the primary characteristics of engineering college students’ involvement in out-of-class activities (OA) at one private college in China through the use of the translated and culturally adapted Chinese version of the Postsecondary Student Engagement Survey (PosSES 2.1). This study provides the statistical analyses of the survey data completed by 283 senior engineering students on their perceptions about their levels of involvement related to positive/negative outcomes students perceive and affective engagement. Data results showed all levels of involvement have a significant influence on positive outcomes. Besides, active involvement degree, hours, and types of …

Optimal Analytical Methods For High Accuracy Cardiac Disease Classification And Treatment Based On Ecg Data, Jianwei Zheng

Computational and Data Sciences (PhD) Dissertations

This work constitutes six projects. In the first project, a newly inaugurated research database for 12-lead electrocardiogram signals was created under the auspices of Chapman University and Shaoxing People's Hospital (Shaoxing Hospital Zhejiang University School of Medicine). This database aims to enable the scientific community in conducting new studies on arrhythmia and other cardiovascular conditions. In the second project, we created a new 12-lead ECG database under the auspices of Chapman University and Ningbo First Hospital of Zhejiang University that aims to provide high quality data enabling detection of the distinctions between idiopathic ventricular arrhythmia from right ventricular outflow tract …

Applying Human Factors Heuristic Evaluation Tools To Improve Aviation Weather Displays: A Mismatch, John Kleber, Paige Lawton, Beth Blickensderfer

General Aviation Weather Display Interpretation

The evaluation of current Heuristic Evaluation Tools for use in assessing Aviation Weather Displays.

Air Navigation And Covid-19: Atm Efficiency In Pandemic Crisis, Fabio Lourenco Carneiro Barbosa

Graduate Student Works

The coronavirus crisis effects on aviation in 2020 are currently well-documented. Nonetheless, the widely registered low traffic due to the crisis does not necessarily lead to increased air navigation efficiency. Thus, the present work, developed to fulfill the program outcomes for the Master of Science in Aeronautics, Air Traffic Management (ATM) specialization, aimed to investigate what was the impact of the COVID-19 crisis on air navigation efficiency in Brazil. This research question was addressed through a quantitative, nonexperimental, observational approach with two parallel branches, designed to answer two sub-questions. For the first, regarding what was the impact of the crisis …

Quantifying Mucosal Hemodynamics In A Murine Model Of Ulcerative Colitis With Diffuse Reflectance Spectroscopy, Elizabeth A. Bullard, Ariel I. Mundo, Shelby N. Bess, Kathryn P. Miller

Biomedical Engineering Undergraduate Honors Theses

Ulcerative colitis (UC) is a gastrointestinal, autoimmune disease that causes ulceration and inflammation of the colon with an incidence 10 out of every 100,000 people in North America and Western Europe. Though the exact etiology is uncertain, a number of studies have shown that inflammatory cells along with environmental factors, genetics, and lifestyle habits can contribute to the sustained inflammatory response. In order to determine the cellular mechanism behind relapse and remission of UC, researchers have frequently employed immunohistochemistry, western blotting and gene sequencing, but these destructive analysis methods require the removal of a sample, necessarily limiting these methods to …

Evaluating Cellular Response Of Different Valve Interstitial Cell (Vic) Phenotypes To Angiotensin I, Smit Patel

Biomedical Engineering Undergraduate Honors Theses

Calcific Aortic Valve Disease (CAVD), one of the leading causes of death in the United States, is characterized by diminished functioning and limited movement of the aortic valve (AV) due to increased thickening, disorganized extracellular matrix elastin fibers, increased collagen content, and abnormal deposition and formation of calcium nodules on the AV [1, 2]. There are two types of CAVD: i) Aortic valve sclerosis (AVS), in which patients suffer from tissue hardening, fibrosis, and early calcification, and ii) calcific aortic stenosis (CAS), representative by excessive calcification on the AV and reduced AV opening, are the two main forms of CAVD …

Economic Feasibility Of Mixed Plastic Waste Pyrolysis Using Twin Reactor System In Northwest Arkansas, Carol Rogers, Patricia Means, Renato Gonzalez, Kaida Sheets, Hayden Townsend

Chemical Engineering Undergraduate Honors Theses

Plastic waste generation is increasing at an unsustainable rate while recycling solutions remain stagnant. As a chemical means of recycling, mixed plastic waste pyrolysis can generate synthetic oil appropriate for use as fuel in power generation from plastic waste that otherwise accumulates in landfills. With the scaling of a commercial plastic pyrolysis process in Northwest Arkansas (NWA) modeled after an operational sawdust pyrolysis unit in Huntsville, Arkansas, economic analysis resulted in 26.3% internal rate of return. Therefore, construction of a commercial mixed plastic-to-fuel pyrolysis plant is economically justified and should be pursued. To effectively implement the proposed design, NWA must …

Using Empirical Data To Design And Validate Hybrid Simulation Models Of Human Behavior In Service Operations, Mohammed Farhan

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

The purpose of this research is to examine how a change in a team member's role, team dynamics, and organizational policies impact an individual's motivation to engage in helping behavior, as well as the impact of helping behavior on service system operational performance. To analyze these behavioral dynamics in a dynamic setting, this research integrates empirical human behavioral data into a hybrid discrete-event and agent-based simulation model of service operations in a restaurant. The model was then validated using Metamorphic Testing (MT), an approach that has previously been used for verification of software. Recent research shows that MT can be …