Engineering Commons^™

Effects Of Alternative Jet Fuels On Aerospace-Grade Composites: Experimental And Modeling Studies, Naoufal Harich

Theses and Dissertations

The aviation industry aims to reduce its environmental impact through innovation and research. The usage of composite materials for multiple primary structures represents one such measure. Several alternative fuels were approved and used along with the Federal Aviation Administration (FAA). These alternative fuels are produced from wastes and biomasses. Some alternative fuels were initially only approved as drop-in fuels, meaning they must be blended with conventional fuels to operate. Fuel tanks are usually embedded into the wing structure, which is mainly made of composite materials. These composites tend to absorb fluids it encounters through their matrix phase. The absorption behavior …

Evaluation Of Conservation Practices Effect On Water Quality Using The Swat Model, Vivek Venishetty

Theses and Dissertations

The deterioration of water quality due to human-driven alternations has an adverse effect on the environment. More than 50% of surveyed surface water bodies in the United States (US) are classified as impaired waters as per the Clean Water Act. The pollutants affecting the water quality in the US are classified as point and non-point sources. Pollutant mitigation strategies such as the selective implementation of best management practices (BMPs) based on the severity of the pollution could improve water quality by reducing the amounts of pollutants. Quantifying the efficiency of a specific management practice can be difficult for large watersheds. …

Aggregate Characteristics For Unpaved Highway Shoulders, Jessica V. Lewis

Theses and Dissertations

This thesis studied unpaved highway shoulders, and in particular shoulders of lower volume asphalt pavements being overlaid. The primary objective was to better understand how different shoulder aggregates perform on lower volume routes with asphalt surfaces and relatively narrow shoulders. A literature review and an evaluation of a full-scale test section containing five aggregate categories in nine test sections over a thirty-four-month period were the primary efforts performed to evaluate unpaved highway shoulders. The study concluded shoulder width measurements were not especially informative, and that California Bearing Ratio measurements were only modestly informative. Crushed concrete outperformed all other aggregates, though …

Managing Iron Deficiency Chlorosis (Idc) In Soybean Through A Cropping System Approach, Katelin Savannah Waldrep

Theses and Dissertations

Iron deficiency chlorosis (IDC) is a frequent problem throughout many areas of the United States where soils are high in calcium carbonate (CaCO₃), including the Blackland Prairie regions of Mississippi. The main objectives of this study were to 1) determine the effects of seven different cropping systems on IDC visual symptomology and grain yield in rainfed soybeans grown in calcareous soils, and 2) evaluate the effects of soil water tension (SWT) on IDC. Rotating soybeans with corn produced significantly higher yields for both tolerant and susceptible soybean varieties. IDC symptomology was worse, and yields were lower in cropping …

A Screening Tool For The Implementation Of Electric And Thermal Energy Storage Systems At Commercial And Industrial Facilities, Mckenna P. Amerson

Theses and Dissertations

The integration of on-site renewable systems with energy storage devices is an important topic in improving energy management for commercial buildings and industrial facilities. Energy storage technologies have the ability to impact the end user’s power reliability while creating measurable energy and cost savings. However, the potential yet remains to increase the application of these systems. To determine the feasibility of renewables and energy storage in commercial and industrial applications, a pre-screening software tool is developed using data-driven algorithms to complete an energy, cost, and carbon savings analysis of storage implementation. A case study of a standalone retail building is …

Risk Assessments And Modeling Of Driver By Using Risk Potential Theory, Riku Kikuta

Theses and Dissertations

Recently, various self-driving and driving assistance systems such as Advanced Driver Assistance System (ADAS) have been developed with the intent to reduce the number of motor vehicle accidents. While self-driving systems have been proven to reduce traffic accidents, the systems sometimes make other drivers confused because of their mechanical behavior. To avoid confusion and possible error, it is necessary to construct self-driving systems that exhibit human-like behaviors. Risk Potential theory has been used to construct models that successfully represent driver behavior, especially expert behavior. This project uses Risk Potential theory to construct and evaluate a collision avoidance driver model which …

Lateral Swelling Pressure In Variably Saturated Expansive Clay, Steven Ray Garrett

Theses and Dissertations

Lateral swelling pressure induced in expansive soils upon wetting can adversely impact the performance and integrity of earthen structures and foundations. The yearly cost associated with damage to structures from expansive clays in the United States is estimated to exceed the loss associated with natural disasters such as earthquakes, floods, and hurricanes. The main objective of this dissertation is to provide new insight into the evolution of lateral swelling pressure in variably saturated expensive soils under infiltration via physical testing. In the first part of this study, a new laboratory-scale testing apparatus was built to measure lateral and vertical swelling …

Evaluation Of Early Maturing Cultivars, Optimal Harvest Timing, And Canopy Reflectance Of Peanut To Maximize Grade And Yield, Joseph Bryan Whittenton

Theses and Dissertations

Peanut digging timing is difficult to predict due to indeterminate growth and peanut pods maturing underground, resulting in the need to research methods that provide consistent measurements, while reducing time and effort for farmers and researchers. Experiments were conducted to evaluate the accuracy of the Maturity Index 1 and Maturity Index 2 in predicting peanut grade, the accuracy of the North Carolina 2 degree day method in predicting peanut yield, and remote sensing vegetative indices sensitivity equivalence (SEq) to peanut Maturity Index 2 and harvest grade (TSMK) for cultivars IPG-914 and Georgia-06G in Mississippi.

Maturity Index 1 and …

An Electric Commerce Platform For Material Testing Laboratories, John Ferris Mitchener

Theses and Dissertations

The emergence of the Internet has allowed businesses to create new sales and marketing channels to provide value for their customers in the marketplace. Engineering manufacturers and suppliers have taken advantage of the internet to automate the customer service aspects of their businesses as well as to market their services in a cost-effective but widespread manner. This work aims to apply the practices and benefits of electronic commerce (e-commerce) to a material testing laboratory through the creation of a functioning website with e-commerce features. The effects of Search Engine Optimization, website accessibility issues, marketing considerations, security concerns, and common business …

Passive Vs. Active Wearable Technology Monitoring Trunk Flexion In Elementary Teachers, Bailey Jose

Theses and Dissertations

The objective of this study was to assess the biomechanical and subjective measures of elementary school teachers while wearing active and/or passive wearable devices during the average workday. Five elementary school teachers wore a harness that held an Upright GO 2 posture tracking device and a Vicon Blue Trident sensor on the participant's upper back for two school days. Haptic feedback was on for one day and off for the other. Data from the Vicon wearable was analyzed to determine participants’ trunk flexion severity, frequency, and duration. Surveys were used to determine perceived exertion and perception of wearable technology. This …

Integrating Steel Slag Aggregates Into Asphalt Paving By Harmonizing Availability, Quality, Economics, And The Environment, Timothy R. Murphy

Theses and Dissertations

This thesis provides guidance on how to balance matters related to the environmental stewardship, market sources, origin and uses, material properties, performance, and economic impact of using slag materials in pavements. The literature on this topic provides numerous references on the use of slag materials for specific applications, and this thesis aims to make use of those references along with other data from the author to describe slag materials from a holistic perspective and provide some suggestions for balancing several factors that impact optimal use of this resource within pavement structures. Discussion is given to the increased importance of recycling …

Wildfire-Altered Geotechnical Soil Properties And Their Impact On Subsequent Landslides, James M. Kellogg

Theses and Dissertations

Wildfires result in altered landscape as well as altered soil properties. Wildfires result in conditions that are more susceptible to geotechnical hazards introducing a potential for cascading events in the surrounding area. Shallow landslides are common geohazards that result in a post-wildfire landscape. With an ever-increasing trend in wildfires, the need to better understand the impact wildfire-altered soil properties play on shallow slope instability is critical to evaluating risks to existing or planned development, mitigation of potentially hazardous conditions, prioritization of post-wildfire planning, and post-wildfire response preparation. The primary objective of this study is to provide a comprehensive overview of …

Synthesis Of Biomass-Based Graphene Nanomaterials For Aqueous Heavy Metal Removal And Cement-Based Composite Property Enhancement, Tharindu N. Karunaratne

Theses and Dissertations

Utilizing biomass such as lignin, bamboo, soybean, corn stalk, rice husk, etc., as a carbon source to produce graphene-based nanomaterials has been reported recently. However, the potential of using such nanomaterials for engineering and environmental applications has not been realized. This dissertation investigates the use of graphene-based nanomaterials synthesized from using biomass as a carbon source for water remediation and cement-based composites’ (CBCs) property enhancement.

The first chapter introduces graphene and graphene-based nanomaterials, as well as the synthesis and application of graphene-based nanomaterials for removing heavy metals in an aqueous solution and for property enhancement in CBCs. The experimental investigation …

Adaptive Large Neighborhood Search Algorithm – Performance Evaluation Under Parallel Schemes & Applications, Sandip Kumar

Theses and Dissertations

Adaptive Large Neighborhood Search (ALNS) is a fairly recent yet popular single-solution heuristic for solving discrete optimization problems. Even though the heuristic has been a popular choice for researchers in recent times, the parallelization of this algorithm is not widely studied in the literature compared to the other classical metaheuristics. To extend the existing literature, this study proposes several different parallel schemes to parallelize the basic/sequential ALNS algorithm. More specifically, seven different parallel schemes are employed to target different characteristics of the ALNS algorithm and the capability of the local computers. The schemes of this study are implemented in a …

Unmanned Aerial System Integration Safety And Security Technology Ontology, Rebecca A. Garcia

Theses and Dissertations

Unmanned Aerial System (UAS) is a versatile and essential tool for law enforcement, first responders, utility providers, and the general public. Integrating the UAS into the National Airspace System (NAS) poses a significant challenge to policymakers and manufacturers. A UAS Integration Safety and Security Technology Ontology (ISSTO) has been developed in the Web Ontology Language (OWL) to aid in this integration. ISSTO is a domain ontology covering aviation topics corresponding to flights, aircraft types, manufacturers, temporal/spatial, waivers and authorizations, track data, NAS facilities, air traffic control advisories, weather phenomena, surveillance and security equipment, and events, sensor types, radio frequency ranges, …

A Generalizable Method And Case Application For Development And Use Of The Aviation Systems – Trust Survey (As-Ts)., Jamison Hicks

Theses and Dissertations

Automated systems are integral in the development of modern aircraft, especially for complex military aircraft. Pilot Trust in Automation (TIA) in these systems is vital for optimizing the pilot-vehicle interface and ensuring pilots use the systems appropriately to complete required tasks.

The objective of this research was to develop and validate a TIA scale and survey methodology to identify and mitigate trust deficiencies with automated systems for use in Army Aviation testing. There is currently no standard TIA assessment methodology for U.S. Army aviation pilots that identifies trust deficiencies and potential mitigations.

A comprehensive literature review was conducted to identify …

The Effect Of Four Decades Of Deregulation On Competition And Productivity Of The U.S. Freight Transportation Industry, Seungjae Shin

Theses and Dissertations

This study reviews the competition and productivity of the U.S. freight transportation industry for the past 41 years. This study investigated the trends of HHI market concentration index values and labor productivity values of rail and truck sectors and tried to find any relationships between the two values in the separate periods before and after the abolishment of the ICC. This study also investigated how the existence of a regulatory body impacted productivity of the freight transportation industry by using a Cobb Douglas production function on annual financial statement data in the U.S. stock exchange market. This study found that: …

Advancements In Geospatial Monitoring Of Structures, Jordan Keith Baldwin

Theses and Dissertations

The need for advancements in geospatial monitoring of structures has evolved naturally as structures have become larger, more complex, and technology has continued to rapidly develop. Greater building heights generally lead to greater challenges for surveyors, limiting the practical use of traditional measurement methods. For this reason, a new complimentary method was developed and implemented to support elevation monitoring activities during construction of the Salesforce Tower in San Francisco, California. While some studies have explored the use of strain gauges to monitor strain development within individual members, the primary contribution of this work is that it presents a practical and …

Eddy Current Defect Response Analysis Using Sum Of Gaussian Methods, James William Earnest

Theses and Dissertations

This dissertation is a study of methods to automatedly detect and produce approximations of eddy current differential coil defect signatures in terms of a summed collection of Gaussian functions (SoG). Datasets consisting of varying material, defect size, inspection frequency, and coil diameter were investigated. Dimensionally reduced representations of the defect responses were obtained utilizing common existing reduction methods and novel enhancements to them utilizing SoG Representations. Efficacy of the SoG enhanced representations were studied utilizing common Machine Learning (ML) interpretable classifier designs with the SoG representations indicating significant improvement of common analysis metrics.

Developing Systems Engineering And Machine Learning Frameworks For The Improvement Of Aviation Maintenance, Fatine Elakramine

Theses and Dissertations

This dissertation develops systems engineering and machine learning models for aviation maintenance support. With the constant increase in demand for air travel, aviation organizations compete to maintain airworthy aircraft to ensure the safety of passengers. Given the importance of aircraft safety, the aviation sector constantly needs technologies to enhance the maintenance experience, ensure system safety, and limit aircraft downtime. Based on the current literature, the aviation maintenance sector still relies on outdated technologies to maintain aircraft maintenance documentation, including paper-based technical orders. Aviation maintenance documentation contains a mixture of structured and unstructured technical text, mainly inputted by operators, making them …

Physics-Based Modeling Of Post-Wildfire Landslides In Unsaturated Hillslopes, Masood Abdollahi

Theses and Dissertations

Changes in climatic regimes and land use have led to increases in wildfire activities around the world. Wildfires are now happening more frequently, at higher altitudes, and higher severities. Adverse impacts of wildfires can last years after the fire has been contained through post-fire geohazards, such as shallow landslides. Post-wildfire shallow landslides are often mobilized by rainfall and due to fire-induced changes in soil and land cover properties and near-surface processes. This study aims to develop a physics-based framework to evaluate the stability of burned hillslopes against rainfall-triggered shallow landslides. A coupled hydromechanical infiltration model is developed by employing a …

Relaxing Dc Capacitor Voltage Of Power Electronic Converters To Enhance Their Stability Margins, Ali Zakerian

Theses and Dissertations

Recently, due to the increasing adoption of distributed energy resource (DER) technologies including battery energy storage (BES) and electric vehicle (EV) systems, bidirectional power converters are becoming more popular. These converters are broadly utilized as interface devices and provide a bidirectional power flow in applications where the primary power supply can both supply and receive energy. A dc capacitor, called the dc-link, is an important component of such bidirectional converters. For a wide range of applications, the converter is required to control the dc-link voltage. Commonly, a proportional-integrating (PI) controller is used by the dc capacitor voltage controller to generate …

Student-Led Success: Improving Attendance And Learning At Fourth Hour Review Sessions, Andrew C. Gilbert

Senior Honors Projects, 2020-current

This research continues the work of Gilbert et al. [1] by translating the “Fourth Hour” review session materials from Java to Python, keeping the focus on common misconceptions in the literature, continuing to use Peer Instruction (PI), and addressing two issues in the previous study: low attendance and short-term learning outcomes during the session. [2] The “Fourth Hour” is a review session designed to support students taking CS1 who may have missed class or need to review the previous week’s material. This review session is an hour long and is offered twice a week with the same material so more …

Covenant Persuasion Lead To Constitutionalism – Neither Was Invented, Joseph Livni

Helm's School of Government Conference - 2021-2024

Constitutionalism is a conviction shared by people that a government must act in compliance with a dominant charter. So is covenantal persuasion. The covenant reflects statutes and traditions etched in a living covenantal practice. The practice cannot exist without the persuasion and the persuasion cannot exist without the practice. Elazar was one of the most prolific scholars of the covenantal model. There is one point were the paper diverges from Elazar. The paper discusses a mathematical model and other studies of the covenant practice demonstrating that such a practice involves a multitude of simultaneous vital conditions. That led to the …

Introduction To Data-Driven Systems For Plastics And Composites Manufacturing, Saeed Farahani, Srikanth Pilla, Yun Zhang, Fausto Tucci

Mechanical Engineering Faculty Publications

Applications of high-performance plastics and composites have widely been expanded to various industries due to their superior properties, such as high strength-to-weight ratio, chemical resistance, and thermal/electrical insulation. However, the numerous possible combinations of polymers and reinforcements/fillers, the variability of these materials, and their complex manufacturing processes pose challenges in terms of efficiently developing new plastics and composites, accurately modeling their properties, and effectively monitoring and controlling their manufacturing processes. Integrating data-driven techniques, such as machine learning, artificial intelligence, and big data analytics, is a promising pathway to overcome these challenges as it is demonstrated by the state-of-the-art research works …

Research And Application Of Dynamic Compaction Treatment Method For Highway Subgrade In Karst Development Area, Liu Xiaoming, Wang Yigang, Zhao Minghua

Journal of China & Foreign Highway

This paper utilizes discrete-continuum coupled numerical simulation to investigate the failure modes of karst cave roofs with varying spans under specific compaction energy levels. The relationship between the span of the cave roof and the compaction energy required to cause roof collapse is established, providing an estimation method for the maximum unsupported span of cave roofs within the subgrade area. Based on this, the stability of karst cave foundations under the influence of subgrade loads can be evaluated. Depending on the results, a double-layer reinforced continuous concrete slab can be installed in the pavement base to enhance stability and mitigate …

Comparative Analysis Of Asphalt Pavement Performance Prediction Models Based On Gamma And Markov Processes, Ma Shibin, Chen Yonghao

Journal of China & Foreign Highway

Pavement performance prediction is a critical component of pavement management systems, serving as an essential basis and prerequisite for decision-making in asphalt pavement maintenance. This paper introduces the relevant theories of Gamma and Markov stochastic processes to construct asphalt pavement performance prediction models and address uncertainties related to pavement degradation. The results show that stochastic process models are effective in predicting pavement performance degradation and service life. Matlab programming was used to predict asphalt pavement performance and lifespan, yielding pavement degradation curves that significantly improve prediction accuracy and reliability. Finally, taking a test road section in Hebei Province as an …

Study On Interlayer Bonding Properties And Influence Factors Of Cape Seal, Li Yan, Zhang Chengxue, Qiu Yeji, Zhang Haijun

Journal of China & Foreign Highway

To address pavement issues such as shoving and rutting caused by insufficient bonding strength in cape seal layers, this paper investigates the interlayer bonding properties and influencing factors of cape seal. Mechanical tests were conducted using a pavement interlayer shear-pull testing device. Through interlayer pull-off, direct shear, and torsional shear tests, the maximum tensile force, shear force, and torque at failure were obtained. The interlayer bonding performance of cape seal was analyzed in terms of gravel coverage rates, as well as upper and lower layer combinations. The results show that when the gravel coverage rate is 80%-90%, and the cape …

Fracture Mechanics‐Based Fatigue Study Of Corrugated Steel Webs, Li Haidi, Yang Lei

Journal of China & Foreign Highway

To develop fatigue analysis and evaluation methods for corrugated steel web structures, constant-amplitude fatigue load tests were conducted on experimental beam models, supplemented by fatigue test data from domestic and international studies. The finite element submodeling method was employed to obtain stress distribution functions at structural details, and the weight function method was used to derive the stress intensity factor at the crack tip. The Paris law in fracture mechanics was applied to derive the S-N curve for corrugated steel web structures. Comparative analysis with fatigue test results shows that when the initial crack depth is set as a0=t/20 (accounting …

Research On Multi‐Source And Heterogeneous Data Integration Of Large Bridge Health Monitoring System, Wang Daijun, Zhou Tiantu, Fu Junmin, Chen Xing, Lu Shuai, Yu Zheng

Journal of China & Foreign Highway

Large bridge health monitoring systems are characterized by numerous sensors, diverse types, various communication methods, and flexible network configurations. The multi-source heterogeneous nature of the data poses significant challenges for data integration. To address the application requirements of bridge health monitoring, this paper designs a multi-source heterogeneous data integration scheme. The scheme achieves structured storage of multi-source heterogeneous data and introduces the concept of “structured communication.” This enables structured communication configuration, unified communication control, and flexible data processing, standardizing and simplifying communication configuration management in data acquisition systems. These improvements enhance code simplicity, maintainability, and the overall integration level of …