Engineering Commons^™

Stressed Oxidation Of Hafnium Diboride In Air At 1500°C, Thomas A. Bowen

Theses and Dissertations

Hypersonic vehicles with narrow airfoils produce thin boundary layers and shock temperatures in excess of 2000°C, exceeding the operating limits of traditional aerospace materials. The use of ultra-high temperature ceramics (UHTCs) allows for operating temperatures far exceeding those of metallic alloys. One such UHTC is hafnium diboride (HfB₂). Transition metal diborides generally experience significant oxidation degradation at elevated temperatures. The use of additives, such as silicon carbide (SiC) has been shown to reduce the oxidation of transition metal diborides. This research focused on the compressive creep of HfB₂ with varying amounts of SiC in air at 1500°C. …

Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite At 1200°C In Air And In Steam, Nicholas J. Boucher

Theses and Dissertations

The tension-tension fatigue behavior of an advanced melt-infiltrated (MI) silicon carbide/silicon carbide (SiC/SiC) ceramic matrix composite (CMC) was investigated at 1200 degrees Celsius in air and in steam. The MI composite consisted of ten 0/90 plies of Hi-Nicalon-S SiC fibers woven in a five harness satin weave (5HSW), a CVI BN interphase to provide a weak fiber-matrix interphase, and a CVI SiC matrix layer followed by infiltration with SiC particulate slurry and molten silicon. Nine tensile specimens of the material were used in a pilot investigation of mechanical performance at elevated temperature. One specimen was used in a monotonic tensile …

Small Fixed-Wing Aerial Positioning Using Inter-Vehicle Ranging Combined With Visual Odometry, Benjamin M. Fain

Theses and Dissertations

There has been increasing interest in developing the ability for small unmanned aerial systems (SUAS) to be able to operate in environments where GPS is not available. This research considers the case of a larger aircraft loitering above a smaller GPS-denied SUAS. This larger aircraft is assumed to have greater resources which can overcome the GPS jamming and provide range information to the SUAS flying a mission below. This research demonstrates that using a ranging update combined with an aircraft motion model and visual odometry can greatly improve the accuracy of a SUASs estimated position in a GPS-denied environment.

Experimental Validation Of A Heterogeneous Radar Clutter Statistical Estimation Method, Elliot R. Erstein

Theses and Dissertations

Radar clutter models are important for radar target detection when clutter is present. A new method for estimating single clutter type, homogeneous, radar clutter statistics through measurement of a multiple type, heterogeneous clutter was developed in 2015 by researchers at the Air Force Institute of Technology. The estimation method is greatly valued in the clutter research and modeling world for reducing clutter campaign measurement time and cost. This thesis looks at validation steps for the estimation method through the use of simulations and experimental radar clutter measurements.

A Framework For Analyzing And Discussing Level Of Human Control Abstraction, Clifford D. Johnson

Theses and Dissertations

It is often useful to understand the impact of an artificial teammate upon human workload in human-machine teams. Levels of Autonomy (LoA) differentiate systems based on control authority. Unfortunately, human workload is not necessarily correlated with LoA. An alternate classification framework, designated the Level of Human Control Abstraction (LHCA), is proposed. LHCA differentiates system states based on the control and monitoring tasks performed and the level of decisions made by humans. The framework defines five levels, designed to differentiate between system states based upon anticipated levels of human attention. This presentation will summarize the framework and demonstrate its application.

Applying Cyber Threat Intelligence To Industrial Control Systems, Matthew P. Sibiga

Theses and Dissertations

A cybersecurity initiative known as cyber threat intelligence (CTI) has recently been developed and deployed. The overall goal of this new technology is to help protect network infrastructures. Threat intelligence platforms (TIPs) have also been created to help facilitate CTI effectiveness within organizations. There are many benefits that both can achieve within the information technology (IT) sector. The industrial control system (ICS) sector can also benefit from these technologies as most ICS networks are connected to IT networks. CTI and TIPs become resourceful when using indicators of compromise (IOCs) from known ICS malware attacks and an open source intrusion detection …

Satellite Communications In The V And W Band: Natural And Artificial Scintillation Effects, David A. Smith

Theses and Dissertations

In a natural atmospheric environment the troposphere will be the primary source of loss with the ionosphere loss being negligible. If the ionosphere was disturbed from a high altitude nuclear explosion (HANE) more than three times the amount of electrons would be present in the ionosphere and could represent a source of significant loss. In order to determine the amount of electrons distributed from a HANE, GSCENARIO, developed by Defense Threat Reduction Agency was used. The two sources of loss that were examined was signal absorption and amplitude scintillation. Signal loss was determined using GSCENARIO and amplitude scintillation loss was …

Light Olefin Production By Cracking Nannochloris Oculata Microalgae Using Aluminosilicate Catalysts, Gaurav Goyal

USF Tampa Graduate Theses and Dissertations

The global demand and sustainability concerns for producing light olefins encouraged researchers to look for an alternative and sustainable feedstock. Alkenes, such as ethene, propene and butene, are known as light olefins. Olefins are the backbone of the chemical industry because they serve as the chemical building blocks for the manufacture of polymers, fibers, and numerous organic chemicals. Feedstocks such as naphtha, natural gas and liquefied petroleum gas (LPG) are currently used for producing light olefins, but they are non-renewable and hence unsustainable. In contrast, biomass as a potential feedstock for the production of fuels and chemicals is renewable. Microalgae, …

Formation Flight Of Earth Satellites On Kam Torus Using Classical Orbital Elements, Marissa C. Reabe

Theses and Dissertations

This research uses the KAM theory that has been refined by Wiesel to show that Earth-satellites dynamics can be represented by an integrable Hamiltonian system with a small perturbation, like Earths geopotential. The satellite will follow a torus in phase space and remain on that KAM torus for all time unless acted on by a non-conservative force. A torus frequency was calculated, in this research, using a truth model in System Tool Kit (STK) and the High Precision Orbit Propagator (HPOP) to develop an accurate ephemeris file listing the Classical Orbital Elements (COEs). The frequencies found from the truth model …

Evaluating The Autonomous Flying Qualities Of A Simulated Variable Stability Aircraft, Ali M. Hamidani

Theses and Dissertations

Delivering communications from high altitudes, at airspeeds of just 30 knots, gathering data from active volcanoes and forming hurricanes, and collecting ISR over hostile territories, UAVs are at the ready to perform those missions that are too dull, dirty, or dangerous for manned aircraft. However, the proliferation of this new technology has its fair share of challenges. Over 460 DoD UAV mishaps have occurred since 2001, with almost half resulting in damages of $2M or more. One incident almost ended in fatalities, when a UAV, suffering from loss of control, collided with a C-130. That loss of control is what …

Building Energy Model Calibration For Retrofit Decision Making, Nicolas R. Johnson

Dissertations and Theses

Accommodating the continued increase in energy demand in the face of global climate change has been a worldwide concern. With buildings in the US consuming nearly 40% of national energy, a concerted effort must be given to reduce building energy consumption. As new buildings continue to improve their efficiency through more restrictive energy codes, the other 76.9 billion square feet of current building stock falls further behind. The rate at which current buildings are being retrofit is not enough and better tools are needed to access the benefits of retrofits and the uncertainties associated with them. This study proposes a …

Electric Bus Systems. A Case Study And Optimization Study, Florida Solar Energy Center, Nan Qin

FSEC Energy Research Center®

Pure electric buses (EBs) offer an alternative fuel for the nation's transit bus systems. To evaluate EBs in a transit setting, this project investigated the five electric bus fleet of the StarMetro transit system of the city of Tallahassee, FL. For the study, the implementing strategy, route distances and timings, charging times, fuel economies, impact of chargers, and maintenance and operational characteristics were analyzed. The results were compared to a baseline five diesel bus fleet. The results showed that even with a four-fold improvement in fuel efficiency, the operational costs of electric buses were only 10% lower than that for …

Fuel Cell Vehicle Technologies Final Report, Florida Solar Energy Center, Nan Qin

FSEC Energy Research Center®

Fuel cell electric vehicles (FCEVs) use hydrogen as fuel and exhaust only water and heat. They provide driving ranges and fueling times comparable to gasoline vehicles. Despite the advantages, FCEVs have been in and out of the spot light of the auto industry for the past several decades. As FCEVs finally moved from concept demonstration to commercialization in 2015, it is critical to analyze the opportunities and challenges this technology brings. This project placed emphasis on four areas: (1) Analysis of the development of FCEVs from a historic and technology point of view; (2) analysis of hydrogen fueling station infrastructure …

Energy From Thin Air: Compressed Air Power Harvesting Systems, Zachary Sadler, Matthew Jones

Journal of Undergraduate Research

Energy is an important resource within the world we live. The demand for power requires new energy resources. Much of the power that is generated is eventually wasted in the form of waste heat. As much as 435 GW of energy is transferred from virtually all energy conversion devices and processes to the atmosphere as wasted heat ^[1]. Converting as much as one percent of this waste heat into electrical power would eliminate the need for 18 average size (236 MW) ^[2] coal red power plants. A significant portion of this waste heat production is due to air compression …

Effects Of Microstructure And Alloy Concentration On The Corrosion And Tribocorrosion Resistance Of Al-Mn And We43 Mg Alloys, Hesham Y. Saleh Mraied

USF Tampa Graduate Theses and Dissertations

The design of new engineering materials resistant to both wear damage and corrosion degradation becomes increasingly demanding in complex service conditions. Unfortunately, there is typically a tradeoff between wear and corrosion resistance, even for important passive metals such as Al alloys. This is because the presence of precipitates hardens the material but at the same time lead to unfavorable galvanic coupling between the precipitates and the matrix, resulting in accelerated corrosion. This work showed that Al (or Mg) supersaturated solid solution formed using non-equilibrium methods exhibited enhanced corrosion resistance without compromising strength. For Al, alloying with Mn up to ~ …

Design Of An O-Type Metamaterial Slow Wave Structure For High Power Microwave Generation, Sabahattin C. Yurt

Electrical and Computer Engineering ETDs

The aim of this dissertation is to design a novel metamaterial slow wave structure (MSWS) for high power microwave (HPM) generation which is an efficient and compact new generation O-type device whose output parameters are comparable to, and even better than conventional devices. There is increasing interest in using metamaterials for designing HPM sources because of their so-called unique electromagnetic properties that are not found in nature, such as below cutoff propagation, which is the main property that allows for a compact design, and negative refractive index that allows backward wave propagation and reversed Cerenkov radiation. As such new beam/wave …

Emerging Business Models For Open Source Hardware, Joshua M. Pearce

Department of Materials Science and Engineering Publications

The rise of Free and Open Source models for software development has catalyzed the growth of Free and Open Source hardware (also known as “Libre Hardware”). Libre Hardware is gaining significant traction in the scientific hardware community, where there is evidence that open development creates both technically superior and far less expensive scientific equipment than proprietary models. In this article, the evidence is reviewed and a collection of examples of business models is developed to service scientists who have the option to manufacture their own equipment using Open Source designs. Profitable Libre Hardware business models are reviewed, which includes kit, …

Supernode Transformation On Parallel Systems With Distributed Memory – An Analytical Approach, Yong Chen

Engineering Ph.D. Theses

Supernode transformation, or tiling, is a technique that partitions algorithms to improve data locality and parallelism by balancing computation and inter-processor communication costs to achieve shortest execution or running time. It groups multiple iterations of nested loops into supernodes to be assigned to processors for processing in parallel. A supernode transformation can be described by supernode size and shape. This research focuses on supernode transformation on multi-processor architectures with distributed memory, including computer cluster systems and General Purpose Graphic Processing Units (GPGPUs). The research involves supernode scheduling, supernode mapping to processors, and the finding of the optimal supernode size, for …

Proof Of Concept: Development Of Snow Liquid Water Content Profiler Using Cs650 Reflectometers At Caribou, Me, Usa, Carlos L. Pérez Díaz, Jonathan Muñoz, Tarendra Lakhankar, Reza Khanbilvardi, Peter Romanov

Publications and Research

The quantity of liquid water in the snowpack defines its wetness. The temporal evolution of snow wetness’s plays a significant role in wet-snow avalanche prediction, meltwater release, and water availability estimations and assessments within a river basin. However, it remains a difficult task and a demanding issue to measure the snowpack’s liquid water content (LWC) and its temporal evolution with conventional in situ techniques. We propose an approach based on the use of time-domain reflectometry (TDR) and CS650 soil water content reflectometers to measure the snowpack’s LWC and temperature profiles. For this purpose, we created an easily-applicable, low-cost, automated, and …

Interference Mitigation, Resource Allocation And Channel Control Techniques For 4g And Beyond Systems, Mustafa Harun Yilmaz

USF Tampa Graduate Theses and Dissertations

The usage of the wireless communication technologies have been increasing due to the benefits they provide in our daily life. These technologies are used in various fields such as military communication, public safety, cellular communication. The current systems might not be sufficient to meet the increasing demand. Therefore, the new solutions such as the usage of smart antennas have been proposed to satisfy this demand. Among different solutions, cognitive heterogeneous networks (HetNets) have been recently introduced as a promising one to meet the high user demand. In cognitive Hetnets, there are secondary base stations (SBSs) with secondary users (SUs) and …

Fatty Acid Biomarker Detection For Breast Cancer Using Differential Mobility Spectrometry With Non-Radioactive Ion Source, James Joseph Alberti

USF Tampa Graduate Theses and Dissertations

Differential Mobility Spectrometry (DMS) using a non-radioactive ion source (NRIS) is investigated as a possible medical diagnostic instrument for near real-time detection of breast cancer biomarkers. In previous clinical studies, concentrations of Linoleic, Palmitic and Stearic fatty acids have been observed at different levels in women with carcinoma breast cancer versus women with benign tumors or healthy women showing no signs of breast cancer. Present diagnostic methods require a biopsy of the suspect tissue and a microscopic lab analysis performed to determine its disease state. This process can take hours or days before the patient and doctor are informed of …

Media Velocity Considerations In Pleated Air Filtration, Frederik Carl Schousboe

USF Tampa Graduate Theses and Dissertations

Asset protection in the form of fluid filtration makes up an ever-increasing part of the civilized and industrialized world. Fluid filtration applications in the conditioned environment and life sciences are affording the world’s population a chance to better realize their potential, while industrial applications help ensure that high demand processes can be carried out safely, reliably, and effectively.

In the present work, a tool has been developed, using the computational fluid dynamics package FLUENT, to allow the designer to better predict the magnitude of geometric imperfections within a given pleat configuration.

Pleated rectangular filters, intended to improve the quality of …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• CEIT Faculty Lead Cybersecurity Workshop for Robins AFB

Orthoplanar Spring Based Compliant Force/Torque Sensor For Robot Force Control, Jerry West

USF Tampa Graduate Theses and Dissertations

A compliant force/torque sensor for robot force control has been developed. This thesis presents methods of designing, testing, and implementing the sensor on a robotic system. The sensor uses an orthoplanar spring equipped with Hall-effect sensors to measure one component of force and two moment components. Its unique design allows for simple and cost effective manufacturing, high reliability, and compactness. The device may be used in applications where a robot must control contact forces with its environment, such as in surface cleaning tasks, manipulating doors, and removing threaded fasteners. The compliant design of the sensor improves force control performance and …

Heat Flux Modeling Of Asymmetrically Heated And Cooled Thermal Stimuli, Matthew Hardy

USF Tampa Graduate Theses and Dissertations

Thermal sensation is one of the most dynamic stimulus-response systems in the human body. It is relied upon for safety, comfort and general equilibrium of the human body. Thermal sensation is dependent upon many variables such as area of effected skin, rate of temperature change and location of stimulation. It has been shown that certain rates of change can intensify the sensation of heating or cooling. Conversely, sufficiently low rates of change can go undetected by the skin. As such, the thermal response system can be manipulated by the proper combination of applied hot and cold stimuli. Previous research has …

Session 1c (Source Water Protection), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• The Pleasant Grove Spring Non-Point Source Pollution Study: An Underused Data Set, James Currens, Kentucky Geological Survey
• Kentucky’s Source Water Protection Program, Robert Blair, Kentucky Division of Water
• Assistance Program for Source Water Protection: Success in Kentucky, Laura Norris and Allan Shingleton, Kentucky Division of Water

Session 2c (Sediment And Nutrients), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Real-Time Continuous Monitoring of Nutrients and Biological Parameters in Kentucky’s Rivers and Lakes, Mac Cherry, USGS Indiana-Kentucky Water Science Center
• Sediment Transport Modeling using Dynamic (Dis)connectivity to Assess Sediment Impacts on Water Quality, Tyler Mahoney and others, Dept. of Civil Engineering, University of Kentucky
• Sediment Nitrogen and Nitrate Dynamics of a Fluviokarst System in the Bluegrass Region: Isotopic and Numerical Modeling Investigation, Admin Husic and others, Dept. of Civil Engineering, University of Kentucky

Poster Session 2, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

1. GIS as a Tool to Inform Field Studies and Reduce Human Health Exposure Risks, Evan Willett and others, Dept. of Civil Engineering, University of Kentucky
2. The Use of Environmental DNA to Detect Bacterial Molecular Markers in the Triplett Creek Watershed, Rowan County, Kentucky, Rachel Brown and others, Dept. Biology and Chemistry, Morehead State University
3. Detection of Percopsis ominsomaycus (TROUT-PERCH) using eDNA in Eastern Kentucky Streams, Ben Brammell and others, Dept. of Natural Sciences, Asbury University
4. Seasonal Fluctuations in Salamander eDNA in Central Kentucky Streams, Ronald Sams and others, Dept. Natural Sciences, Asbury University
5. Virtual 3D Septic …

Session 2b (Biology), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Microscale Electrokinetics for Phytoplankton Analysis, Stuart Williams, Mechanical Engineering Dept., University of Louisville and Susan Hendricks, Hancock Biological Station, Murray State University
• Selenium Reduction by a Co-Culture of Pantoea vagans strain EWB32213-2 and Shigella fergusonii strain TB42616, Yuxia Ji and Yi-tin Wang, Dept. of Civil Engineering, University of Kentucky
• Effects of Temperature and Macronutrient Ratios (N:P) on Microcystis aeruginosa Toxin Production and Growth, Brandon Yates and Brian Reeder, Dept. of Biology and Chemistry, Morehead State University

Session 1b (Agriculture And Water), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Feathered or Four-Legged: Working Together to Manage Manure in Kentucky, Amanda Gumbert and others, College of Agriculture, Food, and Environment, University of Kentucky
• There’s a Purple Cow in My MS4, Steve Higgins, College of Agriculture, Food and Environment, University of Kentucky
• Field Scale Characterization of Soil Hydraulic Conductivity and its Implication for Irrigation Management, Xi Zhang and Ole Wendroth, Dept. Plant and Soil Sciences, University of Kentucky