Engineering Commons^™

Exploratory Analysis Of Cislunar Disposal Options For Select L1 And L2 Orbit Families, Rene Velazquez

Theses and Dissertations

The purpose of this research is to characterize the disposal options available for the planar and out of plane orbit families near the Moon. These options are meant to provide the impending Space Race around the cislunar regime a method to mitigate debris in the future. The disposal options are built upon a Sphere of Influence (SOI) reachability concept from a Circular Restricted Three-Body Problem (CR3BP). The SOI reachability will be based on the maneuver applied on a closed orbit in the velocity direction of the rotating frame. The post-maneuver trajectories will be propagated for 180 days and transformed into …

Optimal Trajectory Solutions For Unmanned Pursuer/Evader Offensive Counterair Including Engagement Zone, Alexander Hansen

Theses and Dissertations

This work considers a two-actor scenario of a faster, unmanned pursuer with an engagement zone (EZ) and a non-maneuvering mobile evader. The pursuer aims to capture an evader with a circular EZ. The EZ is dynamic and shifts as a function of the evader’s velocity vector. As the evader’s strategy changes, the EZ relative to the pursuer adjusts based on relative heading and speed of the two agents. Using nonlinear optimal control techniques, the optimal trajectory and minimum time to engage the evader are determined for various pursuer initial headings and positions through MATLAB simulation. The results build a control …

Preliminary Architecture Assessment Of Lunar Surface Sensors For Cislunar Ssa, Clint J. Spesard

Theses and Dissertations

The exploration of the lunar and cislunar realm is becoming increasingly active as several entities, private and public, foreign and domestic, set their sights beyond traditional Earth-centered space operations. Along with this renewed activity is a growing need for comprehensive Space Situational Awareness (SSA) and Space Traffic Management (STM) in the inherently chaotic cislunar system. This thesis seeks to embolden the study of cislunar SSA by considering the lunar-surface as a platform from which to conduct optical SSA. In this thesis, a lunar-based SSA system is heuristically optimized via a genetic algorithm through three separate implementations. All surface locations considered …

End-User Device Management In The Air And Space Forces, Joshua Bonvissuto

Theses and Dissertations

When achieving technical superiority is a matter a national security, it is critical that the Department of the Air Force (DAF) employs a robust Information Technology Asset Management (ITAM) strategy that maximizes mission effectiveness. Since 2022, the Office of the Chief Information Officer (SAF/CN) has been developing a plan to transform the Air Force’s ITAM strategy, primarily intending to centralize End User Device (EUD) procurement to the DAF level. For this study, a Delphi study was conducted to gather expert opinions on key aspects of SAF/CN’s new ITAM strategy to identify strengths, weaknesses, and implementation challenges. This research provides valuable …

Utilization Of The System Engineering Design Process To Design And Test A Low-Cost Infectious Aerosol Control Mechanism For Patient Aeromedical Evacuation, Sara Shaghaghi

Theses and Dissertations

The aeromedical evacuation of military patients is a critical component of care for Armed Forces members. The Air Force’s ability to transport patients relies on the technology and systems available. A vital transport responsibility is keeping the patient and medical personnel safe during transport. The historical and legacy systems provide reliable transport mechanisms for the Armed Forces’ patients infected with high-level biological agents, but drawbacks must be considered. This dissertation will discuss the development, conceptual design, and initial evaluation of a new low-cost, litter-mounted patient transport system, Biological-Mitigation in Patient Transport (B-MIPT), using the “V” model of the system engineering …

Advanced Oxidation Of Methyl Tert Butyl Ether With Ultraviolet Light Emitting Diodes, Aaron R. Neal

Theses and Dissertations

Methyl Tert-Butyl Ether (MTBE) is a volatile, soluble, organic compound introduced to gasoline within the United States as a fuel oxygenator in 1979. MTBE is a common groundwater pollutant due to its high water solubility and resistance to bio-degradation; it commonly infiltrates groundwater sources via leaking underground storage tanks or fuel spills. This research employed ultraviolet light emitting diodes (UV-LEDs) and hydrogen peroxide (H₂O₂) induced advanced oxidation process (AOP) to treat MTBE contaminated water at the bench scale. Using four H₂O₂:MTBE molar peroxide ratios (100:1, 200:1, 400:1, 500:1), MTBE degradation was induced …

Origami Application And Attitude Control Investigation Of Space-Based Mirror System, David J. Garcia

Theses and Dissertations

Imaging and inspecting Resident Space Objects (RSO) have gained increasing importance in Space Situational Awareness (SSA) missions. These missions are driven by the necessity to perform satellite repairs, refueling, de-orbiting, and orbital debris reduction. However, the challenging lighting conditions in space often hinder these tasks. To overcome this challenge, a novel concept has been proposed—deploying mirrors from servicer satellites. These mirrors would harness solar energy to illuminate dimly-lit RSOs, enabling imaging, inspection, repair, and refueling operations. In this context, servicer satellites play a pivotal role in controlling the reflected light beam and precisely positioning themselves to illuminate RSOs effectively. Notably, …

3- And 6-Degree-Of-Freedom Investigation Of Aerobraking To Support Cislunar And Planetary Operations, Erica C. Higginbotham

Theses and Dissertations

The first aerobraking experiment occurred in 1991 as part of the Hiten spacecraft’s cislunar survey mission, while the first non-Earth aerobraking experiment occurred in 1993 as part of the Magellan spacecraft’s mission to Venus. Although making only two trans-atmospheric passes to reduce its apogee altitude, the success of Hiten’s experiment led to the implementation of aerobraking by Magellan, reducing its orbit from elliptical to nearly circular over a span of 70 Earth days by leveraging aerodynamic drag to reduce its orbital energy via transiting the upper region of Venus’ atmosphere. The Magellan experiment helped prove the viability of aerobraking for …

Evasion Strategies For Space Engagements With Unknown Pursuer Objectives, Stephanie L. Halsey

Theses and Dissertations

Realistic simulations provide a tool for operators to understand space tactics and also serve to inform decisions on the requirements of current spacecraft technologies. This research uses simulation to gain a better understanding of one-on-one orbital conflicts through orbital differential games and linear quadratic games. The results of this research find that a simple strategy for an evading spacecraft to successfully evade a more-capable pursuing satellite for a variety of potential goals is to thrust perpendicular to the direction of the pursuer. Specific estimation requirements to accurately determine the objective of the pursuer and successfully evade in a realistic scenario …

A Nonlinear Least Squarees Approach To Orbit Determination In Near-Earth Orbits, Ryan M. Vorst

Theses and Dissertations

This work explores relevant scenarios to implement a Frequency on Arrival method using nonlinear least squares to determine a transmitting satellite’s orbit based only on measurements of the received radio frequency. Multiple relevant collection geometries, such as a target in prograde low earth orbit, in retrograde low earth orbit, in sun synchronous orbit, in near-perigee highly elliptical orbit, in near-apogee highly elliptical orbit, and in geosynchronous orbit, are simulated to collect theoretical received frequency data. Once data collection has been simulated, the theoretical apparent frequencies recorded are used in a nonlinear least squares method with differential correction to find a …

Evaluating Butterfly Orbits In The Earth-Moon Corridor For Ssa, Lunar Surface Surveillance, And Cislunar Disposal, Contessa G. Norris

Theses and Dissertations

The increased space activity in the region of cislunar space has created a high demand to identify, track, and monitor Resident Space Objects (RSOs) and provide cislunar disposal routes for RSOs. This research investigates the practicality of various satellite maneuvers between orbits chosen from the butterfly and dragonfly orbit families. Several simulated trajectories are compared to show the feasibility of performing a maneuver in cislunar and lunar space between the L1 and L2 Lagrange points. Additionally, lunar surface space situational awareness (SSA) capabilities of northern and southern butterfly (BN/BS) orbits were evaluated and compared to provide the most favorable dynamic …

Properties Of Portland Cement Concrete Incorporating Basalt-Based Pozzolanic Cement, Rana Khalil

Theses and Dissertations

Over the last decade, the world's population has increased dramatically. Due to this growth, the demand for concrete and Portland cement, in return, have increased. Manufacturing of Portland cement is an energy-intensive process that, alone, contributes to about 8% of global CO2. For decades, efforts have been exerted to reduce the harmful environmental impacts of Portland cement by reducing its use in concrete as well as considering alternate binders that may fully or partially replace it. This study aims to assess the properties of concrete incorporating a novel basalt-based pozzolanic cement. To meet this objective, four sets of concrete mixtures …

Assessing Adoption Barriers Of Sustainable Packaging In Egypt, Carol Ramses Morgan

Theses and Dissertations

Sustainable packaging has become an essential part of business decisions and corporate directions. With the rise of environmental damages due to improper waste management and unsustainable practices, businesses have a major responsibility to analyze their products’ life cycles and redesign them with sustainability in mind. Applying sustainable packaging could save companies large amounts of resources, therefore cutting costs, while also achieving the legal and social duty as a corporation towards society and the environment. Many developing countries, with specific focus on Egypt, have recently focused on legislative and corporate decisions in order to encourage more sustainable practices. Egypt’s new Waste …

Prediction Of Distresses In Pavement Networks: A Machine Learning Approach, Mahmoud Kotb

Theses and Dissertations

The quality of pavement networks is greatly affected by different distresses. These distresses appear in many forms, such as cracking, potholes, rutting and different types of deformation. As a result, to ensure effective pavement management, accurate modeling of these different distresses has become essential. Moreover, machine learning models have shown great potential in modeling pavement performance in recent years. The objective of this research is to develop machine learning models for modeling key parameters of pavement distress, specifically the International Roughness Index (IRI), fatigue and longitudinal cracking. Data for this investigation were extracted from the Long-Term Pavement Performance (LTPP) database, …

Applicability Of Using Bio-Receptive Concrete For Building Facades In Egypt, Gina Roupheil

Theses and Dissertations

The significant increase in carbon dioxide emissions caused by the construction industry is detrimental to our planet. This is rapidly increasing with the urbanization of cities that is gradually taking its toll on the available green spaces, which help in balancing such emissions. Recently, researchers have been trying to make use of bio-receptivity to create biomaterial systems that could be spread on building envelopes and support the growth of small plant species and microorganisms to establish on. Out of those materials, comes the concrete as a promising material for bio-colonization.

Within this context, this study aims at investigating the applicability …

Thermal Insulation And Fire Protection Plaster For Frp System Incorporating Aerogel Nanoparticles And Phyllosilicates, Athnasious Ghaly

Theses and Dissertations

For more than two decades, new innovative materials have been introduced to the market such as nano materials that can be utilized for their high performance in different aspects of the construction industry. Structural repair and strengthening is one of the most demanding fields in the construction industry for innovative and high-performance materials due to its specialty. Time, quality, economy, and sustainability are the main factors that control this field, and for that, new systems keep being introduced to the market to reduce the time of repair and enhance its efficiency. Fiber Reinforced Polymers (FRP) Systems are the most advanced …

Consumers' Acceptance To Buy And Dispose Of Recycling Textile Products, Roa Alsayed

Theses and Dissertations

The textile industry is the second most polluting worldwide, following food manufacturing. It is one of the industries that is rarely scrutinized in the Middle East and North Africa (MENA) region. This work analyzes the fashion industry from the perspective of consumer attitudes towards the purchase and disposal of clothing, and their behavior with regards to old garments. The study was conducted in Saudi Arabia and Egypt, two countries that achieved similar results in the fashion industry. The methodology is divided into three phases. First, the manuscript begins with a review of topics such as sustainability, consumer behavior in the …

Yieldnet: Intelligent Fruit Yield Estimation For Selected Orchards Using Deep Learning Based Semantic Segmentation, Maheswari P

Theses and Dissertations

Agriculture contributes more resources for developing sustainable economic growth of the nation. Precision agriculture employs advanced techniques (machine learning and deep learning) for developing the intelligent systems of various agricultural applications. Among various agricultural tasks, yield estimation of crops plays a vital role in decision-making such as harvesting, marketing, cultivation practices, etc. Traditionally yield estimation is performed manually which has major drawbacks i.e., needs experts opinion, time-consuming and it is a challenging task for big orchards. To overcome these issues, an intelligent yield estimation model using neural network-based systems is required.

Some of the literature works have been explored for …

Investigation Of Fault Detection And Redundant Control Strategy For Model Predictive Control Of Distillation Column, Rajalakshmi R

Theses and Dissertations

Model Predictive Controller (MPC) is one of the industrial-ready control systems and an ideal choice for complex, slow-varying, and energy-intense Distillation Columns (DC). However, MPCs are subjected to failures and their performance degrades with faults and disturbances. Hence, there is a need for a redundant control strategy to ensure the continuous operation of MPC-controlled DC, which is investigated in this work.

A pilot-plant binary DC used to separate methanol and water is implemented with a computer-controlled system and is subjected to Pseudorandom Binary Excitation Signals (PRBS). The output response acquired is used to develop a MIMO (Multi-Input Multi- Output) state-space …

Developing And Forecasting The Egyptian Construction Cost Index, Mayada Elsaied

Theses and Dissertations

Accurate cost estimation is pivotal for the success of construction projects, yet the industry grapples with challenges related to cost overruns. Uncertainties and unforeseen variables often introduce discrepancies, particularly during the planning phase. Economic changes, considered uncontrollable risks, significantly influence these fluctuations. Various research endeavors have quantified the impact of economic conditions on construction costs, emphasizing the correlation between economic indicators and project expenses. Addressing these challenges, the Construction Cost Index (CCI), a tool introduced by Engineering News Record (ENR), accurately delineates the correlation between economic changes and construction costs. Despite its global efficacy, an Egyptian Construction Cost Index is …

An Efficient Regression Testing Suite Optimization System With Iso Quality Factors, Prakash V

Theses and Dissertations

Regression testing is a black-box testing technique. It is utilized to validate an alteration in code in the software to ensure whether it has affected the present performance of the product. It has also been used to assess the adjusted variants of the product. Moreover, software testing is the most efficient process in Software Development Life Cycle (SLDC).

The study introduces Green cloud computing, incorporating computer resources such as foundations, PCs, application administrations, and information stockpiling. Notably, the research imbibes reliability, dependability, and maintainability as quality meters in the validation process. The goal of the proposed system is to implement …

Design And Development Of Deep Eutectic Solvent Assisted Pressurized Liquid Extraction Of Nutraceuticals, Harish Babu B

Theses and Dissertations

Over recent decades, the usage of nutraceuticals has been exponentially increasing as alternates to pharmaceutical drugs. However, extraction of these therapeutically significant compounds from their corresponding sources requires the use of volatile organic solvents like hexane, ethanol and chloroform which increases the global warming potential. This problem has been overcome in recent decades by the use of supercritical carbon dioxide (SCO2) as the extraction solvent. Since SCO2 is non-polar in nature, the extraction of polar compounds with better efficiency is questionable.

On the other hand, modernization in solvent engineering has created generations of green solvents like ionic liquids (ILs), deep …

Hybrid Hydrolysis And Fermentation Of Prosopis Juliflora Pods For Biohydrogen Production By Dark Fermentation, Gayathri G

Theses and Dissertations

The rapid consumption of fossil fuels has resulted in the energy crisis and many environmental issues, including air pollution and the greenhouse effect. Hydrogen is the independent source of the highest energy content, with 122 KJ g-1. Biohydrogen produced from lignocellulosic biomass (LCB) is an excellent alternative fuel for its cleanability, renewability and sustainability. Biohydrogen production from dark fermentation using lignocellulosic biomass provides low cost and a sustainable pathway to utilize a vast amount of waste.

Dark fermentation has considerable potential for hydrogen production because it does not require sunlight, allowing for full-time operation and minimizing bioreactor complexity. The major …

Power Allocation For Next Generation Iot Systems Using Cnoma, Srikamu C

Theses and Dissertations

The global Pandemic/COVID-19 keeps people connected through wireless commu- nication. The tremendous growth of mobile data traffic and an increase in massive IoT connectivity among different devices leads to a scarcity of wireless resources. One of the advancing technologies for the 5G Beyond communication network, Non-Orthogonal Multiple Access (NOMA), is used for M2M, V2V, and connecting low-power IoT devices. NOMA outperforms OMA schemes such as FDMA, TDMA, CDMA, and OFDMA of 1G, 2G, 3G, and 4G in terms of data rate, latency, and spectral efficiency. NOMA exploits the multiplexing of signals in the power domain with the same frequency/time, and …

Mri Image Regression Cnn For Bone Marrow Lesion Volume Prediction, Kevin Yanagisawa

Theses and Dissertations

Bone marrow lesions (BMLs), occurs from fluid build up in the soft tissues inside your bone. This can be seen on magnetic resonance imaging (MRI) scans and is characterized by excess water signals in the bone marrow space. This disease is commonly caused by osteoarthritis (OA), a degenerative join disease where tissues within the joint breakdown over time [1]. These BMLs are an emerging target for OA, as they are commonly related to pain and worsening of the diseased area until surgical intervention is required [2]–[4]. In order to assess the BMLs, MRIs were utilized as input into a regression …

Customer Churn Prediction Based On Sentiment Score, Shadha Al-Safi

Theses and Dissertations

In recent years, the telecommunications industry has witnessed intensified competition, wherein the expense associated with acquiring new consumers exceeds that of sustaining existing ones. Consequently, predicting customer churn prior to its occurrence has become essential. This study proposes a sentiment-based customer churn prediction model in which the sentiment of customers is predicted using Random Forest. Subsequently, the derived sentiment predictions are combined with additional features to predict customer churn. The ensemble technique is applied to predict churn, consisting of K-nearest neighbors, Support Vector Machines, Random Forest as base learners, and Multiple Layer Perceptron as a meta learner. Moreover, mutual information …

Degradation Of The Mechanical Properties And Hydrogen Generation In Cement Under Gamma Irradiation Assessed By Atomistic Simulation, Omar Al Najjar

Theses and Dissertations

Although understanding the effect of the gamma-ray on cement-based materials is essential for many applications, such as the concrete contaminate of nuclear reactors or the storage of radioactive waste in cement-based waste forms, such understanding is still not fully developed. The importance of having such an understanding is becoming of utmost importance, especially with calls to extend the lifetime of nuclear power plants, and also due to some recent incidents of failures of the concrete structure in the nuclear fields. In this work, the details of preparing three molecular models as a representative structure of the main binding phase of …

Fair Fault-Tolerant Approach For Access Point Failures In Networked Control System Greenhouses, Mohammed Ali Yaslam Ba Humaish

Theses and Dissertations

Greenhouse Networked Control Systems (NCS) are popular applications in modern agriculture due to their ability to monitor and control various environmental factors that can affect crop growth and quality. However, designing and operating a greenhouse in the context of NCS could be challenging due to the need for highly available and cost-efficient systems. This thesis presents a design methodology for greenhouse NCS that addresses these challenges, offering a framework to optimize crop productivity, minimize costs, and improve system availability and reliability. It contributes several innovations to the field of greenhouse NCS design. For example, it recommends using the 2.4GHz frequency …

Performance Analysis And Evaluation Of Image Processing Techniques, Dcnn And Bsn Model For Detection And Classification Of Diabetic Retinopathy, Sudha S

Theses and Dissertations

Diabetes is a disorder that arises when blood sugar level increases. Insufficient secretion of insulin hormone is the ground for the evolution of diabetes, and it affects most of the critical organs in our body. Diabetes causes leakage of blood in the retinal blood vessels, inducing an eye disease, Diabetic Retinopathy (DR). The visual identification of micro features in fundus images makes the clinicians complex and challenging tasks. Therefore, timely diagnosis and proper treatment can prevent eye blindness. This research is proposed to identify and classify diabetic retinopathy using an Image Processing technique, Deep Convolutional Neural Network (DCNN), Biological Sensor …

The Effect Of Mechanical Strain On The Electronic Conductivity Of Α- Fe2o3: A Density Functional Theory Study, Sheriff Naziru Abdulmutalib

Theses and Dissertations

Hydrogen has emerged as a promising future energy carrier due to its ability to produce zero carbon dioxide (CO2) emissions when burned. However, the limited natural abundance of hydrogen necessitates the development of cost-effective and environmentally friendly methods for large-scale hydrogen production. Among the different hydrogen production approaches, photoelectrochemical water splitting, which employs a photoanode material in a cell using solar energy to split water into hydrogen and oxygen, is the focus of this work. α-Fe2O3 (hematite) is a photoanode material that shows a promising future for hydrogen generation in a photoelectrochemical cells due to its cheapness, availability, and its …