Engineering Commons^™

Experimental Investigations On Mechanical Wear And Corrosion Behaviour Of Sintered Atomet 4601 Based Hybrid Alloys, Palaksha Reddy K

Theses and Dissertations

Powder metallurgy enables the development of new materials to manufacture products for applications requiring unique properties. The present research initially investigates the mechanical and tribological behaviour of powder metallurgy alloys made from ATOMET 4601 prealloyed powder and varying amounts of elemental carbon (0, 0.5, and 1.0 wt%) as reinforcement. ATOMET 4601 is a high-strength, water-atomized prealloyed powder capable of being compressed to higher densities, with applications in producing near-net or net-shaped parts for the industrial field.

Mechanical behaviour studies on sinter-forged ATOMET 4601, ATOMET 4601+0.5C, and ATOMET 4601+1.0C alloy steels revealed increased hardness, tensile strength, and impact strength, with ATOMET …

Nanofiber-Hydrogel Composite Scaffold Fabrication Methods For Peripheral Nerve Regeneration, Jacob Lee Carter

Theses and Dissertations

Nerve graft conduits (NGCs) are a rapidly advancing field for treating peripheral nerve injuries that aim to guide the growth of regenerating axons across damaged gaps. A more effective NGC can be manufactured by combining the use of nanofibers to act as guidewires within a 3-D hydrogel that imitates the extracellular matrix of nerve tissue. Several methods have been developed to embed aligned nanofibers in an ordered architecture within a hydrogel matrix. The first method involves layer-by-layer additive manufacturing to create NGCs with rows of polycaprolactone (PCL) nanofibers surrounded by a gelatin methacrylate (GelMe) hydrogel in a 3-D structure. A …

Development Of Bio-Based Organogels For The Replacement Of Silicone Elastomers In Cosmetic & Personal Care Applications, Courtney A. Lemasney

Theses and Dissertations

Silicone elastomers (SE) are a major component in many cosmetic and personal care products, providing excellent spreading properties, leaving a dry, silky feel on the skin. Unfortunately, the manufacturing of silicone is a high energy consuming process, and these products are not biodegradable. Capryloyl/glycerin/sebacic acid (CGS) copolymers are an economical, nontoxic platform for synthesizing bio-based materials with tailored properties. These polyester networks are formed through esterification with water as its only side product. By altering feed ratios and reaction conditions, final products can vary from branched fluids to highly crosslinked elastomers. This thesis investigated controlling the crosslink density of the …

Effective Integration Of Waste Plastics In Hot Mix Asphalt Mixtures: Towards Sustainable Infrastructure, Venkatsushanth Revelli

Theses and Dissertations

The study investigated the potential of waste plastics such as low density polyethylene(LDPE), high density polyethylene(HDPE), polyethylene terephthalate(PET) and polystyrene (PS) for designing superior performing asphalt mixtures. Both wet mixing and dry mixing methods were adopted for designing plastic modified asphalt mixtures. Initially LDPE and HDPE were selected for developing plastic modified binders, based on melting characterization, determined from differential scanning calorimeter(DSC). In wet mixing process, the influence of dosage, size of plastic, blending duration and interaction between plastic and asphalt were assessed. Plastics were found to exhibit phase separation with asphalt, while finer particles take only longer to segregate …

Low-Power Sensor Design And Fusion To Edge Devices For High-Speed Object Detection And Enhanced Soldier Situational Awareness, Scott Patrick Wood

Theses and Dissertations

Threat detection and physiological monitoring of soldiers from fused sensor data collected in real time is currently limited to running deep neural networks with substantial computing needs. The lack of data acquisition from sensor readings and efficient detection of novel enemy signatures motivates the need for a low-power, low-cost, wireless multisensor fusion computing system. We propose the current trends in Internet of Things to deploy a chargeable, wireless multi-channel acquisition system that can be interfaced to a high speed, Single Board Computer (SBC) such as the NVIDIA Jetson Orin capable of running object detection models, such as YOLOv7-tiny to enable …

Investigating Hardware-Based Aes Countermeasures In The Sam4l Microcontroller For Side-Channel Attack Mitigation, Turki Mesbel Alamri

Theses and Dissertations

Side-channel attacks (SCAs) represent a sophisticated method by which attackers exploit indirect pathways, such as power leakage and electromagnetic emissions to glean sensitive information from microprocessors. These attacks analyze variation in power consumption during operations like data encryption to infer protected data, potentially compromising the security of the device. For example, observing the power draw differences when a device encrypts known data can also serve defensive purposes. Attacks often overlook emissions and power patterns, while focusing on avoiding network and host-based detection systems. This oversight presents an opportunity for security professionals to use SCAs to enhance system defenses by monitoring …

Toward Adaptive And Modular Joint Multi-Domain Operational Planning, Kyle S. Wilkinson

Theses and Dissertations

This research develops a multiparametric optimization framework for modeling joint multi-domain operational planning under uncertainty. We address the application of our framework to model the doctrine of adaptive planning. We apply set-based design, which is a program management practice of maintaining maximal design options through time as a response to epistemic uncertainty. We couple this with a multiparametric optimization method yielding both sets of solutions and sensitivity profiles. We use the sensitivity profiles to quantify risk associated with changes during adaptive planning. This research also models features of military operational planning via the mathematics of category theory. We formalize intuitive …

Heuristic Design Of Cislunar Space Situational Awareness Architectures, Jacob A. Dahlke

Theses and Dissertations

The growing interest in the cislunar domain, which encompasses geosynchronous Earth orbit (GEO), the Moon, and the region where Earth-Moon gravitational effects are the primary influence, necessitates the development of tools to ensure safe and successful exploration. Space situational awareness (SSA) involves monitoring an environment to detect, track, identify, and catalog space objects. While most SSA experience comes from near-Earth operations, expanding into the cislunar domain presents significant challenges due to its vast expanse—greater than 10 times the radius of GEO—and the unique dynamics governed by the Circular Restricted Three-Body Problem (CR3BP) influenced by both Earth and Moon gravitational forces. …

Scene Decomposed Blind Deconvolution And Neural Network Based Multi-Frame Image Restoration Techniques For Astronomical Imagery, Joshua S. Sprang

Theses and Dissertations

Ground based astronomical imaging is an important method in gaining situational awareness of orbiting and far off objects in space. This method of imaging is accessible to everyone that can look up into the sky, but the accessibility to digital telescope systems allows for more exciting methods of extracting information. A use case for these telescopes is finding nearby objects to larger brighter known objects. The number satellites in low-earth orbit and geosynchronous earth orbit is becoming more congested as these orbits increase in population. Tens of thousands of satellites and debris now exist in this orbit, with the number …

Improving Military Medical Evacuation System Performance Via Stochastic Optimization, Virbon B. Frial

Theses and Dissertations

This research highlights the importance of improving the performance of military medical evacuation systems to reduce the risk of permanent disability or death among service members in deployed environments. We employ a range of stochastic optimization techniques relating to integer programming, Markov decision process, approximate dynamic programming, and machine learning, as appropriate, to gain insights into factors that contribute to improving system performance.

Integrating Blockchain Technology Into The Software Development Life Cycle To Satisfy The Software Bill Of Materials Requirement For Government Software Systems, Walter T. Scott Ii

Theses and Dissertations

This thesis explores the integration of Blockchain Technology (BT) into the Software Development Life Cycle (SDLC) to satisfy the Software Bill of Materials (SBOM) requirement for government software systems. This study begins by synthesizing a standard SDLC definition from various government and industry references, which may provide the foundation for future efforts to standardize software development practices across the government software development community. This study proceeds to define working definitions for the software supply chain (SSC) and software supply chain management (SCM) before introducing and detailing the SBOM requirement as well as providing an overview of prior research regarding SBOMs …

An Analysis Of Electrical Energy Resilience Technologies As Applied To Air Force Operations, Eric D. Danko

Theses and Dissertations

An analysis of 46 Resilient Energy Devices and Technology Concepts was conducted to determine their suitability for use in supporting Air Force Operations both at home station and abroad. The research consisted of two endeavors: an extensive literature review and a rank-ordering matrix. The dual nature of the efforts was designed to maximize usability and understanding for the End User, who may not be familiar with some principles of energy technologies, resilience, or design. The results showed the superiority of novel Solid (Metal) Fuels and Lead-Acid Batteries for Energy Storage and Thermoelectric Generators, Solar Photovoltaic Panels, Geothermal Extraction, Diesel Generators, …

Autonomous Experimentation For Accelerated Calibration Of Fused Deposition Modeling 3d Printers, Graig S. Ganitano

Theses and Dissertations

Additive Manufacturing (AM), also known as 3D printing, has emerged as a key component of Industry 4.0, enabling reduced cost, quick production, greater sustainability, and increased design complexity compared to its traditional manufacturing counterpart. Currently, Fused Deposition Modeling (FDM) technology dominates the AM market with respect to the number of 3D printers in use. However, the FDM process is sensitive to changes in system configuration, especially the feedstock material. Utilizing a new feedstock requires a time-consuming trial-and-error process to identify optimal settings for a large number of process parameters, acting as a barrier to the technology.

To enable greater accessibility …

Optimal Placement Of Artificial Hair-Cell Airflow Sensors For Bioinspired Flight-By-Feel, Alex C. Hollenbeck

Theses and Dissertations

The Sparse Sensor Placement Optimization for Prediction (SSPOP) algorithm reduces highdimensional airflow data to a low-dimensional sparse approximation to identify an optimal placement for any number of sensors on airfoil or wing models of arbitrary shape and size, and outperforms conventional optimization techniques in accuracy and speed. For 2D flow this algorithm found a sensor placement solution (design point, or DP) which predicts AoA to within 0.10 degrees and ranks within the top 1 percent of the design space. On 3D wing models SSPOP found four-sensor DPs ranked well within the top 0.10 percent. Experimental validation with velocity and pressure …

Guidance, Navigation, And Control For Multi-Agent Inspection Of An Unknown Space Object, Mark R. Mercier

Theses and Dissertations

On-orbit inspection is a rapidly growing mission that enables extending the life of aging legacy space systems through refueling, replacing, or upgrading components. For an inspection operation, multiple agents taking observations simultaneously can more quickly map an RSO and assure an inspection is complete regardless of RSO dynamics. A multi-agent guidance, navigation, and control (GNC) scheme must be designed with cooperation in mind to achieve inspection objectives, while leveraging the unique capabilities of a distributed inspection system. This work splits the GNC system into two parts composed of an offline guidance scheme for translational reference trajectory generation and an online …

Machine Visual Perception For Autonomous Docking Maneuvers, Derek B. Worth

Theses and Dissertations

This dissertation presents a novel approach to autonomous docking using machine learning for visual perception, particularly during probe and drogue aerial refueling. Autonomous vehicles have become pervasive in both civilian and defense sectors, and their ability to interact with their surroundings and each other autonomously is critical for future operations. Traditional methods relying on signals or inertial sensors face significant limitations such as interference, jamming, and drift. This research focuses on developing a computer vision-based solution to overcome these limitations. A novel pipeline, termed relative vectoring, is introduced, which utilizes dual object detection and machine learning to estimate relative positions …

Generation And Implementation Of Mixed Radiation From Laser Interactions On A Liquid Target, Benjamin M. Knight

Theses and Dissertations

The simultaneous generation of different forms of radiation from the same source is highly desirable but technically challenging. We present the generation of D-D fusion neutrons and >MeV-energy x-rays from extreme intensity (∼ 10¹⁹ W/cm² ), high repetition-rate (1 kHz) laser pulses on a thin liquid target. Total neutron fluxes of ∼ 105 neutrons/s and x-ray exposure rates up to ∼ 200 R/hr at 74 cm are measured. Evidence of D-D fusion is verified with a measurement suite including three independent neutron detection systems: an EJ-309 organic scintillator, a ³He proportional counter, and a set of 36 …

Investigations On Structure-Related Properties Of Organic Inorganic Hybrid Materials For Multifunction, Anu Ranjani E Ms

Theses and Dissertations

Two-dimensional (2D) hybrid halide perovskites have become a versatile material in diverse applications like optoelectronics, lighting and display, magnetism, etc. These materials are often termed as layered hybrid halide perovskites (LHHPs) due to their unique structure with alternate organic and inorganic layers. The presence of insulating organic layers separates the inorganic perovskite slabs, creating a quantum-confined architectural configuration. This unique configuration endows these materials with a spectrum of distinctive functionalities, encompassing photovoltaics, lighting and displays, second harmonic generation, optical limiting, ferroelectricity, and ferromagnetism. The exceptional attribute is that a single LHHP can respond autonomously to external stimuli, such as changes …

Enhancing Security And Privacy For Smarter Environment Through A Robust Cyber-Physical System Framework, Ramya S

Theses and Dissertations

As digital computing paradigm and practices have emerged in disciplines, devices with processors and sensors were rudimentary, performing independent tasks with limited power. The first computer processors were slow, bulky and consuming high energy, as sensors in thermometers and pressure gauges provide original, independent measurements without effective communication, 1999. It often required powerful, energy-efficient processors and advanced sensors to enable seamless communication and sophisticated data processing.

These devices, since smart home systems to industrial automation tools, which continuously collect, analyse and share data via the internet, facilitating if real-time management, predictive maintenance, and improved seamless experience are used, transforming everyday …

Deep Learning Technique For The Classification Of Stress Among The Students Using Physiological Biomarkers With A Hybrid Feature Approach, Rajendran Vg

Theses and Dissertations

Adolescence is a crucial part in life, and the presence of stress, anxiety, depression, and health issues during this stage is a great concern. This research aims to analyze and predict the cognitive stress in students during the examination period using EEG biomarkers. In this study, raw EEG data is acquired under two different experimental conditions, before and after examination, from 14 subjects with an eight-channel Enobio device. After preprocessing of the EEG signal, the brain rhythms such as theta, alpha, and beta sub-band energies and EEG band ratios such as neural activity, heart rate, arousal index, vigilance index and …

Ai In Healthcare: Early Diagnosis Of Skin Cancer Using Medical Image Processing And Deep Neural Networks, Nirmala V

Theses and Dissertations

Several cancer types are commonly prevalent, and skin cancer is one among them, becoming even more widespread worldwide in the last few decades. To diagnose skin cancer at an early stage and obtain appropriate therapy to treat it, there is a demand to know more about the disease’s characteristics or severity. Skin cancer is caused mainly by various reasons, including damage of the sun or tanning beds by ultraviolet light exposure.

Failing to treat skin cancer might substantially impair an individual’s quality of life as the victim. They likely to experience physical issues linked with the deformities caused by psychological …

Effect Of Gas Tungsten Arc Welding Process Variants On The Microstructure And Properties Of Az31b Magnesium Alloy And 304hcu Austenitic Stainless Steel Welds, Srinivasan S

Theses and Dissertations

The automotive and aero sectors seek materials with high specific strength & specific stiffness for enhanced efficiency / emission control. Mg alloys, known for their low density, are used in the as-cast, and wrought forms, depending on the service requirements, and are predominantly used for non-loaded structural parts in varied engineering applications. Welding Mg alloys is of great interest to industry, not only for the fabrication of components but for the repair welding of casting as well. There has been considerable research in the fusion & solid-state welding of Mg alloys. Gas tungsten arc welding (GTAW) has often been preferred …

Investigation On Production, Kinetic Modelling, Downstream Processing, And Characterization Of Microbial Dextran Using Sucrose-Rich Alternate Feedstocks, Sameeha Syed Ar

Theses and Dissertations

Microbial exopolysaccharides (EPS) synthesized by microorganisms have a wide range of applications from thickener agents in the field of food to formulations in the field of pharmaceuticals. Owing to their rheological, structural, and physicochemical characteristics in addition to its biodegradability, low antigenicity, antioxidant activities, etc., several EPS have gained research focus in recent years. Dextran is one such example of EPS, which is synthesized by lactic acid bacteria (LAB). However, its production is limited to utilization of sucrose medium with a yield of 0.3-0.4 g dextran/ g sucrose. Hence, this thesis work focuses on dextran production using sucrose-rich alternate feedstocks …

Experimental Investigation And Evaluation Of Mechanical Properties And Microstructural Characterization On Chromium Molybdenum Steel Processed Through Laser Based Welding, Rakesh S

Theses and Dissertations

Creep Strength Enhanced Ferritic (CSEF) martensitic modified 9Cr-1Mo (P91) steel is extensively employed in fast breeder nuclear reactors and thermal power plants owing to its superior resistance to thermal fatigue and oxidation corrosion compared with other low-alloy steels. Despite its excellent high-temperature performance, the weldability of this steel remains a critical concern.

Conventional arc welding processes generate excessive heat input and complex thermal cycles, resulting in heterogeneous microstructures, retention of δ-ferrite, and subsequent degradation in service life. In contrast, high energy density beam welding techniques such as laser and electron beam welding offer precise thermal control and minimal heat-affected zones …

Remote Sensing Assessment Of Ionospheric Total Electron Content Over Thanjavur Gps Station Geomagnetic 2.91 N 152.22 E, Veera Kumar Maheswaran

Theses and Dissertations

A Global Positioning System (GPS) station for ionosphere studies was established during December 2019 in Thanjavur (Geographic 10.72◦ E, 79.01◦ N, Geomagnetic 2.91◦ N, 152.22◦ E). The study involved analysing Total Electron Content (TEC) data and correcting biases to estimate Slant Total Electron Content (STEC). STEC was then converted to Vertical Total Electron Content (VTEC), useful for space weather, navigation, surveying, and environmental monitoring.

During the course of our study, this Thanjavur station witnessed a Annular Solar eclipse of Dec-26, 2019. The Solar eclipses can impact ionospheric conditions, causing VTEC depletion. This study shows how the near-earth environment changes during …

Sustainable Valorization Of Woody And Herbaceous Biomass For Energy And Environmental Applications, Subramaniyasharma S

Theses and Dissertations

Pyrolysis is a thermochemical conversion method to produce gas and liquid fuels from lignocellulosic biomass. This process involves the thermal decomposition of organic compounds without oxygen. The vapors formed are rapidly condensed to yield a liquid product called bio-oil and a solid product called biochar.

In the present study, Sesame indicum (SI) (herbaceous agro residue) and Prosopis julifora (PJ) (woody biomass weed) were chosen as feedstocks for the pyrolysis process and the respective solid and liquid products were collected and characterized. The proportion of biomass pyrolysis products is significantly influenced by biomass composition and process conditions such as temperature, heating …

Motion Based Analysis Of Ultrasound Imaging For The Study Of Musculoskeletal Tissue Bio Mechanics, Ananth Hari R

Theses and Dissertations

Ultrasound image analysis plays an important role in diagnosing musculoskeletal injuries and monitoring rehabilitation exercises. The first and foremost step in this analysis involves segmentation of region of interest from the ultrasound images. The segmentation of the musculoskeletal tissues from the ultrasound images is challenging due to the inherent drawback present in ultrasound like : (1) Poor image quality due to image corruption by speckle noise, shadows, and attenuation. (2) Dis-continuous boundaries due to orientation dependence during the acquisition of image. (3) Low contrast between nearby anatomical structures. Hence in order to overcome these drawbacks, there is a need for …

Development Of Electrochemical Sensors For The Detection Of Pesticide Residues In Water, Indhu S

Theses and Dissertations

Intentional and unintentional events of pesticide poisoning and their accidental exposure have significantly raised the concerns of global organizations to classify these chemical compounds based on their toxicity, to assign permissible limits, and to appoint task force for periodic monitoring of their presence in water bodies.

In this context, researchers are continually seeking potential alternatives to develop water quality sensors with higher selectivity to obtain the desired performance during real-time assessment. Electrochemical sensors involving interface materials of distinguishing capacity at elevated matrix complexity are desirable. However, there remains a challenge in designing suitable techniques, methodologies, and appropriate validations to support …

Improving Fatigue Characteristics Of Cold Formed Low Carbon Steel, Venkatesan D

Theses and Dissertations

EN353 is a low carbon alloy steel, predominantly used in the manufacturing of heavy-duty gears, shafts, and pinions, especially crown wheel and pinions. It is usually carburized, hardened, and tempered to produce a hard, wear-resistant case. Heat- treated EN353 steel exhibits enhancement in ductility, toughness, strength, and hardness as the internal stresses get relieved in the material. Spheroidizing of medium and high carbon steel is a method of prolonged heating at a temperature below the eutectoid temperature, where pearlite, the lowest energy arrangement of steel, gets converted to ferrite and cementite.

The graphite content of steel assumes a spheroidal shape, …

Identification Of Delamination Defect In Fibre Reinforced Polymer Composite Tapered Plate Based On Vibration Measurement, Venkatesan M

Theses and Dissertations

Fibre-reinforced polymer (FRP) composite plates have been widely used in various engineering applications due to their high strength-to-weight ratio, corrosion resistance, and durability. Despite their many benefits, Delamination is a separation of the layers in composite material and can occur due to various factors such as impact, fatigue, and manufacturing defects. Identifying delamination in composite structures is crucial for ensuring safety and reliability. In this study, model-dependent vibration methods, which are an effective non-destructive technique, were utilised for delamination identification. The primary objective is to investigate the dynamic behaviour of delaminated thickness-tapered plates and develop a reliable methodology for delamination …