Engineering Commons^™

Experimental And Computational Aerodynamic Studies Of Axially-Oriented Low-Fineness-Ratio Cylinders, Forrest Miller

Mechanical & Aerospace Engineering Theses & Dissertations

For the successful completion of atmospheric entry, descent, and landing (EDL) missions, a body geometry must be selected which provides favorable dynamic aerodynamic properties. The types of experimental facilities capable of collecting information on these properties are limited; however, their numbers are growing thanks to the continued work by the aerodynamics community. NASA Langley Research Center (LaRC) is conducting dynamic aerodynamic testing using a subsonic magnetic suspension and balance system (MSBS), with the end goal of implementing a supersonic MSBS facility at NASA Glenn Research Center. MSBSs are also currently used at the Institute of Fluid Science (IFS) at Tohoku …

Ultrasensitive Tapered Optical Fiber Refractive Index Glucose Sensor, Erem Ujah

Biomedical Engineering Theses & Dissertations

Refractive index (RI) sensors are of great interest for label-free optical biosensing. A tapered optical fiber (TOF) RI sensor with micron-sized waist diameters can dramatically enhance sensor sensitivity by reducing the mode volume over a long distance. Here, a simple and fast method is used to fabricate extremely sensitive refractive index sensors based on localized surface plasmon resonance (LSPR). Two TOFs (l = 5 mm) with waist diameters of 5 µm and 12 µm demonstrated sensitivity enhancement at λ = 1559 nm for glucose sensing (5–45 wt%) at room temperature. The optical power transmission decreased with increasing glucose concentration due …

Synthesis And Characterization Of Cobalt(Iii) Complexes And A Vanadium(Iv) Complex With Flavonoids As Ligands, Ethan Schroeder

Chemistry & Biochemistry Theses & Dissertations

For many years now, transition metal complexes have been used as favorable additional chemotherapeutic approaches to medicine that were previously unexplored in the literature. One well-known chemotherapeutic drug, cisplatin, has been applied, but is limited in use due to its toxicity to the cells and its undesirable side effects to humans. Newly developed cobalt-based complexes with ligands known as flavonoids are being used to fight cancer. Flavonoids, compounds mainly found in fruits and vegetables, are shown to have antioxidative and anticancer properties. Use of flavonoids as ligands in transition metal complexes, e.g., those with a Ru(II) metal center, have been …

Oxidation Of Hafnium Diboride—Silicon Carbide At 1500 °C In Air; Effect Of Compressive Stress, Anthony J. Degregoria, Marina B. Ruggles-Wrenn, Glen E. Pry

Faculty Publications

The long-term oxidation behavior of HfB₂ and of HfB₂-20 vol.% SiC was studied. Test samples of each material were oxidized at 1500 °C in air using a box furnace. The exposure times were 0, 0.5, 1, 2, 3, 6, 9, 12, 15, 30, 45 and 90 h. Weight gain, oxide scale composition and oxide scale thickness were characterized for both materials. Crystal structure of the surface scales was analyzed using x-ray diffraction. Oxide scales were further characterized via scanning electron microscopy with energy dispersive spectroscopy analysis. For HfB₂ the oxide scale consists predominantly of porous HfO …

Cyberinet: Integrated Semi-Modular Sensors For The Computer-Augmented Clarinet, Matthew Bardin

LSU Doctoral Dissertations

The Cyberinet is a new Augmented instrument designed to easily and intuitively provide a method of computer-enhanced performance to the Clarinetist to allow for greater control and expressiveness in a performance. A performer utilizing the Cyberinet is able to seamlessly switch between a traditional performance setting and an augmented one. Towards this, the Cyberinet is a hardware replacement for a portion of a Clarinet containing a variety of sensors embedded within the unit. These sensors collect various real time data motion data of the performer and air fow within the instrument. Additional sensors can be connected to the Cyberinet to …

Development, Experimental Validation, And Progressive Failure Modeling Of An Ultra-Thin High Stiffness Deployable Composite Boom For In-Space Applications, Jimesh D. Bhagatji

Mechanical & Aerospace Engineering Theses & Dissertations

To maximize the capabilities of nano- and micro-class satellites, which are limited by their size, weight, and power, advancements in deployable mechanisms with a high deployable surface area to packaging volume ratio are necessary. Without progress in understanding the mechanics of high-strain materials and structures, the development of compact deployable mechanisms for this class of satellites would be difficult. This research focuses on fabrication, experimental testing, and progressive failure modelling to study the deformation of an ultra-thin composite beam. The research study examines deformation modes of a boom under repetitive pure bending loads using 4-point bending setup. The material and …

Reinforcing Digital Trust For Cloud Manufacturing Through Data Provenance Using Ethereum Smart Contracts, Trupti Narayan Rane

Engineering Management & Systems Engineering Theses & Dissertations

Cloud Manufacturing(CMfg) is an advanced manufacturing model that caters to fast-paced agile requirements (Putnik, 2012). For manufacturing complex products that require extensive resources, manufacturers explore advanced manufacturing techniques like CMfg as it becomes infeasible to achieve high standards through complete ownership of manufacturing artifacts (Kuan et al., 2011). CMfg, with other names such as Manufacturing as a Service (MaaS) and Cyber Manufacturing (NSF, 2020), addresses the shortcoming of traditional manufacturing by building a virtual cyber enterprise of geographically distributed entities that manufacture custom products through collaboration.

With manufacturing venturing into cyberspace, Digital Trust issues concerning product quality, data, and intellectual …

Design And Implementation Of A Launching Method For Free To Oscillate Dynamic Stability Testing, Kristen M. Carey

Mechanical & Aerospace Engineering Theses & Dissertations

Magnetic Suspension and Balance Systems (MSBS) allow for static, forced oscillation and free to oscillate dynamic stability testing in a wind tunnel without the need for a physical support. The objectives of study are to assist in the application of the free to oscillate testing method in an MSBS to determine dynamic stability characteristics for various re-entry capsule designs.

This thesis discusses the development and testing of a launching method called the grabber for use in the MSBS Subsonic Wind Tunnel at NASA Langley Research Center. Aerodynamic tests were run to support the use of this method and compare the …

Attention And Task Engagement During Automated Driving, James Richard Unverricht

Psychology Theses & Dissertations

Many young drivers suffer fatal crashes each year in the United States at a rate approximately three times greater than more experienced drivers. Automated driving systems may serve to mitigate young drivers high crash rates but remain underexplored in research. This dissertation project examined the effects of levels of automation and interestingness of auditory clips on latent hazard anticipation in young drivers during simulated driving. Participants drove a vehicle at varying levels of vehicle automation (SAE Level 0, 2, or 3) in simulated scenarios, each containing a latent hazard event during which a boring, neutral, or interesting auditory clip was …

Study Of Microphonic Effects On The C100 Cryomodule For High Energy Electron Beam Accelerators, Caleb James Hull

Mechanical & Aerospace Engineering Theses & Dissertations

The Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson National Laboratory (JLab) is a particle accelerator which can accelerate an electron beam to relativistic speeds and apply the beam onto target samples. The C100 superconducting radio frequency (SRF) cavity is the primary accelerating structure of the C100 cryomodule, one of the many cryomodules which compose the CEBAF linear accelerator. SRF cavities are particularly sensitive to internal and external vibrations that can result in a phenomenon called microphonics which degrade the operational stability of a cryomodule.

The purpose of this thesis is to investigate the significance of mechanical disturbances on …

Biocrude Production From Lignin In Hydrothermal Medium: Effect Of Rapid Heating And Short Residence Time, Kyoko Hirayama

Civil & Environmental Engineering Theses & Dissertations

This study aims to address knowledge gaps in the production of valuable products from waste streams generated during lignocellulosic biofuel production. The primary objective is to develop a process that converts lignin, a byproduct of bioethanol refineries, into a sustainable biolubricant.

The first chapter examines recent advancements in synthesizing biolubricants and investigates their scalability. It explores innovative materials, catalysts, chemical modification approaches, and additives that have emerged in the field. A particular hurdle is the oxidative stability of biolubricants derived from plant oils, which are prone to autooxidation due to their C=C bonds. To overcome this, the study aims to …

An Advanced Simulation Architecture For Testing Autonomous And Connected Vehicles Enabled By Virtual Reality, Defu Cui

Electrical & Computer Engineering Theses & Dissertations

With the advancement of intelligent transportation systems, autonomous driving and connected driving are seen as potential solutions to alleviate traffic congestion, enhance traffic safety, and improve efficiency. Extensive testing and validation of autonomous vehicles (AVs) and connected vehicles (CVs) including connected autonomous vehicles are crucial to ensure their safety and reliability. However, testing and validating AVs and CVs on public roads faces challenges such as high costs, inadequate support from transportation infrastructure with communication technologies, and safety concerns, among others. Simulations have become essential tools for testing autonomous driving and connected driving. As mixed traffic involves multiple domains including traffic …

Data-Driven Predictive Modeling To Enhance Search Efficiency Of Glowworm-Inspired Robotic Swarms In Multiple Emission Source Localization Tasks, Payal Nandi

Mechanical & Aerospace Engineering Theses & Dissertations

In time-sensitive search and rescue applications, a team of multiple mobile robots broadens the scope of operational capabilities. Scaling multi-robot systems (< 10 agents) to larger robot teams (10 – 100 agents) using centralized coordination schemes becomes computationally intractable during runtime. One solution to this problem is inspired by swarm intelligence principles found in nature, offering the benefits of decentralized control, fault tolerance to individual failures, and self-organizing adaptability. Glowworm swarm optimization (GSO) is unique among swarm-based algorithms as it simultaneously focuses on searching for multiple targets. This thesis presents GPR-GSO—a modification to the GSO algorithm that incorporates Gaussian Process Regression (GPR) based data-driven predictive modeling—to improve the search efficiency of robotic swarms in multiple emission source localization tasks. The problem formulation and methods are presented, followed by numerical simulations to illustrate the working of the algorithm. Results from a comparative analysis show that the GPR-GSO algorithm exceeds the performance of the benchmark GSO algorithm on evaluation metrics of swarm size, search completion time, and travel distance.

Mil-53(Fe) Derived Magnetic Cufe2o4/Fe2o3 Composite For Catalytic Oxidation Of Sulfamethoxazole Via Peroxymonsulfate Activation, Abdul H. Asif, Nasir Rafique, Rajan A. K. Hirani, Lei Shi, Yantao Wang, Xiaoguang Duan, Yu Yin, Hongqi Sun

Research outputs 2022 to 2026

Design of metal–organic framework (MOF) derived metal oxides is an effective approach for environmental remediation. The current study describes the fabrication of MIL-53-derived perforated CuFe2O4/Fe2O3 using a facile, one-step, post-thermal solid-state approach by varying Cu/Fe ratios. Herein, the release of CO2 and H2O during the thermal treatment facilitates the incorporation of Cu2+ onto the Fe2O3 structure, forming a perforated hollow CuFe2O4/Fe2O3 composite via an in-situ ion-exchange mechanism. The optimised catalyst CF-0.5 displays a high degradation efficiency for the removal of sulfamethoxazole (SMX) by heterogeneous activation of peroxymonsulfate (PMS), ascribing to the better textural, morphological, and elemental properties of the novel …

Characterizing Logistics Operations Within A Federal Staging Area For Hurricane Response: A Qualitative Analysis Of Federal, State And Local Perspectives, Jannatul Shefa

Graduate Theses and Dissertations

A successful deployment of logistics operations following a disaster is a collective contribution of federal, state, and local entities to ascertain an efficient and effective response. This research analyzes data from interviews with disaster response logistics experts from these entities. The objective is to investigate the information sources and planning processes used in these organizations to plan vehicle routes for critical resource deliveries to impacted areas. Special attention is directed to the impacts of incomplete knowledge of infrastructure status, such as road disruptions due to debris or flooding. Supported by both qualitative and quantitative evidence, the study finds that incomplete …

Effects Of Cobalt Salts On Biomass Conversion To Functional Carbon-Based Catalysts For Peroxymonosulfate Activation, Zhihao Tian, Qianru Chen, Shiying Ren, Huayang Zhang, Wenjie Tian, Hongqi Sun, Shaobin Wang

Research outputs 2022 to 2026

Metal functionalization is an effective structure-engineering strategy for preparing biomass-derived carbon materials, whereas the influences of different metal precursors on the structure and catalytic performance remain unclear. Herein, an investigation of four typical cobalt salts for pyrolytic biomass conversion is performed. The melting points and anion species of cobalt salts are found to be critical factors. Co-salts (cobalt nitrate (Co(NO3)2), cobalt acetate (Co(OAc)2), cobalt acetylacetonate (Co(acac)2)) melted at low temperatures ( ≤ 165 °C) could promote mesopore formation and catalyze the graphitization process of a biomass flower during the carbonization, finally forming mesoporous graphitic carbon matrixes with Co@graphitic-C nanoparticles and …

Visibility Based Hospital Inpatient Unit Design., Uttam Karki

Electronic Theses and Dissertations

Patient fall is one of the adverse events in an inpatient unit of a hospital that can lead to disability and/or mortality. Healthcare literature suggests that increased visibility of patients by unit nurses is essential to improve patient monitoring and, in turn, reduce falls. However, such research has been descriptive in nature and does not provide an understanding of the characteristics of an optimal inpatient unit layout from a visibility-standpoint. This dissertation fills significant voids in this domain and adds much-needed realism to develop insights that hospital decision-makers can use to design their inpatient unit layout. Our first contribution (Chapter …

A Data-Driven Multi-Regime Approach For Predicting Real-Time Energy Consumption Of Industrial Machines., Abdulgani Kahraman

Electronic Theses and Dissertations

This thesis focuses on methods for improving energy consumption prediction performance in complex industrial machines. Working with real-world industrial machines brings several challenges, including data access, algorithmic bias, data privacy, and the interpretation of machine learning algorithms. To effectively manage energy consumption in the industrial sector, it is essential to develop a framework that enhances prediction performance, reduces energy costs, and mitigates air pollution in heavy industrial machine operations. This study aims to assist managers in making informed decisions and driving the transition towards green manufacturing. The energy consumption of industrial machinery is substantial, and the recent increase in CO2 …

Measurement Of Conduction, Radiation, And Convection Thermal Energy To Assess Baking Performance In Residential Ovens., Sean Simpson

Electronic Theses and Dissertations

Residential ovens are complicated thermal environments capable of delivering convection, conduction, and radiation heat transfer to food. The amount and mode of heat transfer can change based on the design of the oven cavity, cooling systems, and oven cycle algorithms. Studies have shown that the changes in one heat transfer mode can have an impact on the quality of baked goods. The many variables involved make designing residential ovens a time consuming and costly process. The goal of this study is to adapt thermal energy sensing technology to collect energy data from a residential oven and develop correlations to quality …

Cad System For Early Diagnosis Of Diabetic Retinopathy Based On 3d Extracted Imaging Markers., Ahmed Sleman

Electronic Theses and Dissertations

This dissertation makes significant contributions to the field of ophthalmology, addressing the segmentation of retinal layers and the diagnosis of diabetic retinopathy (DR). The first contribution is a novel 3D segmentation approach that leverages the patientspecific anatomy of retinal layers. This approach demonstrates superior accuracy in segmenting all retinal layers from a 3D retinal image compared to current state-of-the-art methods. It also offers enhanced speed, enabling potential clinical applications. The proposed segmentation approach holds great potential for supporting surgical planning and guidance in retinal procedures such as retinal detachment repair or macular hole closure. Surgeons can benefit from the accurate …

Experimental And Numerical Studies Of Laser Powder-Bed Fusion Process With Ti-6al-4v Powder: (1) Porosity And Mechanical Properties, And (2) Transient Phenomena In One- And Two-Dimensional Fabrications., Santosh K. Rauniyar

Electronic Theses and Dissertations

Laser powder bed fusion (L-PBF) process represents a form of metal additive manufacturing (AM) where micron-level powdered material is selectively melted and fused layer by layer to create intricate three-dimensional parts. This process involves rapid melting and solidification, leading to intense thermocapillary convection within the molten pool. The melt pool is a crucial element of the L-PBF process and refers to the localized region where the powder particles are melted and solidified to form each layer of the printed part. The shape and dimensions of the melt pool directly influence the accuracy and surface finish of the printed part. Precise …

Changes To Water Quality And Discharge In An Urban Stream In Southwest Jefferson County., Karina Henson

Electronic Theses and Dissertations

Mill Creek is the largest watershed in Southwest Jefferson County, where thousands of people live and work. Streams in the watershed have historically been channelized and altered to promote drainage, and stream health is of major concern. Louisville MSD is currently developing a watershed plan for Mill Creek by seeking understanding of current stream conditions. This paper will focus on historical trends in stream discharge and water quality. Peak and daily discharge, dissolved oxygen, specific conductance, and temperature data from USGS gages at Mill Creek and the Mill Creek Cutoff was analyzed to understand how water quality and flow rates …

Aerodynamic Flow Control Using Micro Rotating Cylinders, Alejandro Daniel Carrizales

Theses and Dissertations

This research investigates the aerodynamic and flow field characteristics of a NACA 0010 airfoil equipped with rotating cylinders near the leading edge, subjected to a flow with a freestream turbulence intensity of 4.3%. The airfoil was modified to integrate five micro-DC motors positioned at 14.5% of the chord length from the leading edge. The cylinders, with dimensions of 0.75 inches in diameter and 0.5 inches in width, exposed 3mm of their length to the incoming flow. A modified leading edge with eight sinusoidal protrusions (tubercles) was employed to compare the performance of the micro-rotating cylinder airfoil with an unmodified baseline …

A Study On The Gaseous Radionuclide Dispersion In The Highway Across Urban Blocks: Effects Of The Urban Morphology, Roadside Vegetation And Leakage Location, Rui Jia, Jianzhi Yang, Xiaowei Zhu, Fusuo Xu, Liping Wang

Mechanical and Materials Engineering Faculty Publications and Presentations

Spent fuel is a used nuclear waste that poses a great hazard to human body and the environment. In this work, the dispersion of gaseous radionuclides from the highway to downstream urban is simulated using CFD based on a hypothetical spent fuel transport accident, with focus on the effects of urban morphology, roadside vegetation and leakage location. The velocity field, TKE (turbulent kinetic energy) distribution and radionuclide concentration under different conditions are carefully explored. The results show that the dispersion of radionuclides is greatly influenced by the velocity field and TKE distribution. The health risk to the residents of sparse …

Educating Older Drivers To Improve Acceptance And Utilization Of Cav Technologies, Ping Yi, Claudia Marovic, Renee Whittenberger

University Research

As the population of older drivers continues to grow, there is an increasing need to enhance their awareness and understanding of Connected and Automated Vehicles (CAVs). This study utilized an education program aimed at improving the knowledge and awareness of older drivers about CAVs, thereby preparing them to utilize the safety features of these technologies while effectively meeting the challenges that come with them. Through data collection and analysis from study participants, the research provides valuable insights for transportation agencies and technology developers to design and develop more adaptive technologies and associated education for older drivers. The findings from this …

Hydrothermal Liquefaction Of Wastewater Sludges For Energy Resource Recovery, Carl L. Abadam

Civil Engineering ETDs

This study aims to identify how variabilities in wastewater process configurations impact the biocrude yields from sludges processed and stabilized by hydrothermal liquefaction. Clean and renewable energy sources are vital to ensure a sustainable future. However, the current consumption of fossil fuels limits the ability to achieve this goal. Hydrothermal liquefaction (HTL) is a thermochemical process that converts wet biomass to valuable biocrude oil and biochar while reducing solid masses. Wastewater sludges were sampled across three facilities with varying influent design capacities and biological treatment configurations. Lipids extracted via solvent extraction and biocrudes produced from HTL were determined gravimetrically. Relative …

Performance Evaluation Of E-Ticketing Technologies On Asphalt Paving Projects In New Mexico, Gena C. Robertson

Civil Engineering ETDs

The collection and processing of paper tickets for construction material delivery is an inefficient and antiquated practice that exposes inspectors on highway paving projects to substantial safety risks. An alternative to the collection of paper tickets is e-Ticketing, which uses web-based systems to deliver similar information. This research documented a current paper ticketing process and compared it to an e-Ticketing process that was implemented on several pilot projects. Data were obtained using stakeholder meetings, personnel interviews, and surveys. When compared to a paper ticketing system, e-Ticketing was shown to have fewer opportunities for error, require fewer decision points, and provide …

Role Of Endophytic Fungi On Arsenic Uptake In Solution: Insights For Bioremediation, Taylor Lillian Busch

Civil Engineering ETDs

Hazardous metals mobilized from natural deposits and mining legacy are environmental and human health concerns. The waters of our partner Native American communities affected by uranium and gold mining legacy exceed the EPA MCL of 10 µg/L arsenic (As). Bioremediation is a novel technology that uses native resources to remediate metals in the soil and groundwater. Plant-fungi symbiosis for bioremediation is widely studied, but the role of endophytic fungi in metal uptake is not well understood. The objectives of this study are to 1) determine As uptake by symbiotic endophyte Cadophora sp. and little bluestem grass (Schizachyrium scoparium) …

Hydraulic Habitat Suitability For The Rio Grande Silvery Minnow At The Los Chavez Irrigation Outfall, New Mexico, Haley A. Ormsbee

Civil Engineering ETDs

It is essential to manage the Middle Rio Grande for aquatic species to preserve the native biodiversity of the river. During periods of low flow, endangered species such as the Rio Grande Silvery Minnow (RGSM) may get trapped in a drying reach without the ability to escape from isolated pools. Very little is known about how areas of refuge, such as irrigational outfall channels, buffer RGSM from stream flow intermittency. Hence, there is a crucial need to quantify available habitat for RGSM in areas of refuge. This study aims to make connections between flow regimes and physical-habitat conditions to help …

Identifying The Required Ecological Flow For Sediment Movement In The Río Chama: Field Data Informed Visual Spatial Model, Cristian Kremer

Civil Engineering ETDs

The continuous alteration of flow regimes in rivers has led to negative impacts on habitats and biotic communities, causing irreversible effects on river biodiversity. Implementing e-flows in management strategies can repair historical mismanagement, prevent further degradation, and restore ecosystem services. In the case of the Rio Chama, damming has altered its hydrological regime, affecting sediment transport. Experts recommend specific e-flow conditions for the Rio Chama to improve ecological conditions, in particular a bankfull discharge of 70 m³s^-1 every 2 years for sediment flushing and channel maintenance. The Río Gallina, a tributary of the Rio Chama, plays a …