Engineering Commons^™

Prevention Of Drone Jamming Using Hardware Sandboxing, Joshua Mead

Graduate Theses and Dissertations

In this thesis, we concern ourselves with the security of drone systems under jamming-based attacks. We explore a relatively new concept we previously devised, known as hardware sandboxing, to provide runtime monitoring of boundary signals and isolation through resource virtualization for non-trusted system-on-chip (SoC) components. The focus of this thesis is the synthesis of this design and structure with the anti-jamming, security needs of drone systems. We utilize Field Programmable Gate Array (FPGA) based development and target embedded Linux for our hardware sandbox and drone hardware/software system.

We design and implement our working concept on the Digilent Zybo FPGA, which …

Validation Of A Confocal Light Sheet Microscope Using Push Broom Translation For Biomedical Applications, Joshua Hutcheson

Graduate Theses and Dissertations

There exists a need for research of optical methods capable of image cytometry suitable for point-of-care technology. To propose am optical approach with no moving parts for simplification of mechanical components for the further development of the technology to the poin-of-care, a linear sensor with push broom translation method. Push broom translation is a method of moving objects by the sensor for an extended field of view. A polydimethylsiloxane (PDMS) microfluidic chamber with a syringe pump was used to deliver objects by the sensor. The volumetric rate of the pump was correlated to the integration time of the sensor to …

Risk Estimation Toward A Natural History Model For Low Grade Glioma Patients, Anh Thi Hoang Pham

Graduate Theses and Dissertations

Glioma is a common type of primary brain tumor that represents 28% of all brain tumors and 80% of malignant tumors. According to a recent study by the Centers for Disease Control and Prevention (CDC), gliomas account for 53%, 35% and 29% of all brain tumors (68%, 74% and 81% of malignant brain tumors) among children (aged 0-14), teenagers (aged 15-19) and young adults, respectively. Gliomas are often diagnosed through radiological imaging and histopathology. There are two main groups of gliomas following World Health Organization’s classification: Low grade gliomas (LGG), or grade I and II gliomas; and high grade gliomas …

Essays In Physicians Preference Items And Inventory Management Within The Healthcare Supply Chain, Mohammad A. Shbool

Graduate Theses and Dissertations

This work is composed of a number of topics in the healthcare area, which are approached separately with appropriate methodologies. The two topics deal with physician preference items via two different approaches. The first one investigates stock keeping unit (SKU) proliferation in healthcare organizations due to physician preference items (PPI). It captures perspectives of physicians and supply chain professionals about this problem through two surveys. The second topic builds a decision-making framework for the PPI selection process that can be used by healthcare organizations to make more objective decisions. A Multi-criteria decision making technique is implemented to illustrate the framework.

Cloning, Fed-Batch Expression And Purification Of A Novel Anti-Candida Peptide And Development Of A Cleavage Resistant Variant Of Green Fluorescence Protein, Rudra Palash Mukherjee

Graduate Theses and Dissertations

This work illustrates that the intelligent design of a bioprocess for the production of peptides of various length is possible by having a prior knowledge of desired product, cell line, fermentation conditions, and choices for downstream recovery. Cloning, expression, and recovery of a novel 12-mer anti-Candida peptide served as an illustrative case for a proposed Escherichia coli platform. The antifungal peptide, expressed as a fusion to GFPUV during high call density fed-batch, was recovered from cell lysate, concentrated using ion exchange chromatography, and finally cleaved with cyanogen bromide. The platform was capable of producing active peptide capable of arresting the …

Control Design Of A Single-Phase Dc/Ac Inverter For Pv Applications, Haoyan Liu

Graduate Theses and Dissertations

This thesis presents controller designs of a 2 kVA single-phase inverter for photovoltaic (PV) applications. The demand for better controller designs is constantly rising as the renewable energy market continues to rapidly grow. Some background research has been done on solar energy, PV inverter configurations, inverter control design, and hardware component selection. Controllers are designed both for stand-alone and grid-connected modes of operation. For stand-alone inverter control, the outer control loop regulates the filter capacitor voltage. Combining the synchronous frame outer control loop with the capacitor current feedback inner control loop, the system can achieve both zero steady-state error and …

Use Of Response Surfaces In The Design Of A Simple Step Stress Accelerated Test Plan, Alexander H. Wong

Graduate Theses and Dissertations

In designing accelerated testing plans, cost is a factor that is missing in much of the literature. This paper explicits considers cost by developing an optimization model with the objective to minimize costs for a simple step stress accelerated test plan. Two methodologies are employed. One is an optimization approach in which an attempt is made to quantify the behavior of a series-parallel hardware system over all stages of testing using a response surface, and then an optimization model is used to determine the settings for stresses and failure mode modifications for all stages of testing prior to the start …

Phase-Field Models For Simulating Physical Vapor Deposition And Microstructure Evolution Of Thin Films, James Stewart Jr.

Graduate Theses and Dissertations

The focus of this research is to develop, implement, and utilize phase-field models to study microstructure evolution in thin films during physical vapor deposition (PVD). There are four main goals to this dissertation. First, a phase-field model is developed to simulate PVD of a single-phase polycrystalline material by coupling previous modeling efforts on deposition of single-phase materials and grain evolution in polycrystalline materials. Second, a phase-field model is developed to simulate PVD of a polymorphic material by coupling previous modeling efforts on PVD of a single-phase material, evolution in multiphase materials, and phase nucleation. Third, a novel free energy functional …

Designing Sewn Circuits And Stem Self-Efficacy In Middle School Girls, Kara Kaiser

Graduate Theses and Dissertations

The purpose of this study is to determine if the experience of designing and sewing LilyPad Arduino circuits in crafts projects can increase middle school girls’ STEM self-efficacy. Boys STEM self-efficacy will also be assessed to determine if LilyPad Arduino circuits can also increase boys’ STEM self-efficacy. Researchers have been wondering why there is a male dominance in STEM (science, technology, engineering and mathematics) fields and why some women do not have a particular interest in these subjects. There are several reasons this could happen; stereotypes conveyed to them by parents and/or teachers, they genuinely are not interested in STEM …

Experimental And Theoretical Analyses Of The Structural, Electronic And Magnetic Properties Of Novel Inverted Core-Shell A-Cr2o3@A-Mxcr2-Xo3-Y (M=Co, Ni, Mn, Fe) Nanoparticles, Mohammad Delower Hossain

Graduate Theses/Dissertations

I used hydrothermal nano-phase epitaxy technique to synthesize well-ordered a-Cr2O3@a-MxCr2-xO3 (M = Co, Ni, Mn, Fe) inverted core-shell nanoparticles (NPs). This resulted in the formation of novel a-MxCr2-xO3 shells having ferromagnetic/ferrimagnetic (FM/FiM) spin ordering and an antiferromagnetic (AFM) a-Cr2O3 core structure. The combined results from Xray diffraction (XRD) and high resolution transmission electron microscoy (HRTEM) provide evidence of the presence of the corundum phase both in the shell and in the core regions. HRTEM results also show a sharp interface exhibiting epitaxial atomic registry of shell atoms over highly ordered core atoms whereas TEM-Energy dispersive spectroscopy analyses show that the …

Molecule Assisted Hydrothermal Synthesis Of Zinc Oxide Nanomaterials With Possible Applicatios In Solar Energy, Austin Major Shearin

Graduate Theses/Dissertations

A molecule assisted hydrothermal synthesis of zinc oxide nanomaterials with L-lysine has been performed to understand the interaction between the biomolecule and the zinc oxide structures during synthesis. The molecule alters the growth kinetics during the formation of the nanomaterials in the hydrothermal reaction. This alters the size and shape of the materials as seen in the scanning electron microscope. X-ray diffraction results confirm the hexagonal Wurtzite structure that zinc oxide forms and indicates no other phases in the nanomaterial. The lattice parameters are not altered, but the atomic percentage of zinc to oxygen within the structure changes as analyzed …

Efficiency And Particulate Matter Emissions Testing Of Wood Burning Heating Units, Collin W. Michael

Chemical Engineering Undergraduate Honors Theses

The University of Arkansas StoveHOGS team developed a method for efficiency and particle emissions testing of wood fired heaters. The EPA currently regulates the particulate emissions of wood burning stoves, and the goal of this project was to develop a cheaper, easier method for small manufacturers to test the efficiency and particulate emissions of wood burning stoves without sending them to a testing facility. The team used EPA and CSA testing standards to design and test a method that could accomplish the same task in a simpler and more cost effective manner.

Experimental Verification Of The Concept Of The Relativistic Magnetron With Simple Mode Converter, Jeremy Mcconaha

Electrical and Computer Engineering ETDs

A compact A6 relativistic magnetron with a simple mode converter for axial TE_11-mode extraction was recently designed at the University of New Mexico. With the standard A6 magnetron operating in the �-mode it is possible to implement a simple mode converter to radiate a TE_11-mode axially through a cylindrical waveguide whose radius is the same as the anode cavity radius. The proposed mode converter implements an anode end cap that electrically opens diametrically opposite cavities that produce an electric field polarization corresponding to that of the of the TE_11-mode in a cylindrical waveguide. The TE_11-mode has a Gaussian-like profile with …

Design And Optimization Of Membrane-Type Acoustic Metamaterials, Matthew G. Blevins

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

One of the most common problems in noise control is the attenuation of low frequency noise. Typical solutions require barriers with high density and/or thickness. Membrane-type acoustic metamaterials are a novel type of engineered material capable of high low-frequency transmission loss despite their small thickness and light weight. These materials are ideally suited to applications with strict size and weight limitations such as aircraft, automobiles, and buildings. The transmission loss profile can be manipulated by changing the micro-level substructure, stacking multiple unit cells, or by creating multi-celled arrays. To date, analysis has focused primarily on experimental studies in plane-wave tubes …

An Evaluation Of Agricultural Tractors Hydraulic Lift Performance, Grant W. Melotz

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The current OECD Code 2 detailing the procedures for the hydraulic lift test of agricultural tractors, section 4.3, published lift values that were sometimes unattainable. The static weight of 2WD, two wheel drive, and MFWD, mechanical front wheel drive, tractors and the amount of lifting force have increased at a greater rate than the amount of static weight on the front axle. This increase in lifting force has led to a decrease in the percent of weight as the upward support force on the front axle of a tractor. Many of the 2WD and MFWD unballasted tractors tested at the …

Tractor Measurement And Data Acquisition System For Hydraulic Power, Draft Force, And Power Take-Off Torque, James Roeber

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Numerous advancements in machinery performance of agricultural tractors have been made in recent years. The Organisation for Economic Co-operation and Development (OECD) tests predetermined points (e.g., maximum power and torque) for drawbar, Power Take-Off (PTO), and hydraulic power as separate tests for tractor performance. Testing methods with the tractor operating at a steady state have been done for years, which were uncharacteristic of agricultural tractor operations in field conditions. As part of this thesis work, field usable data acquisition systems (DAQs) were developed to record implement energy consumption (e.g., drawbar loading, PTO torque, and hydraulic power). The system used LabVIEW …

Cooling And Packaging Of Accumulators For Formula Sae Electric Car, Hang Yin

Mechanical and Aerospace Engineering Theses - Archive

Electric car is the future of automotive industry. The performance of the batteries is vital for that of electric cars. Overheating will compromise the performance of batteries, shorten the life span and even damage the battery permanently. So it is crucial to have an efficient packaging and cooling method. This project using Formula SAE Electric car as the testing ground is dedicated to develop the efficient way of thermal and electronic packaging of accumulators for automobiles.

Development And Flight Test Of Moving-Mass Actuated Unmanned Aerial Vehicle, Sampath Reddy Vengate

Mechanical and Aerospace Engineering Theses - Archive

Conventional airplane control is achieved by aerodynamic control surfaces by generating moments around all the three axes of the aircraft. Defections of the control surfaces have some disadvantages such as induced drag, increase in radar signature, and exposure to high temperature in high speed applications. As an alternative moment generation mechanism, prior research proposed internal mass-actuation, which is to generate gravitational moment by changing the center of gravity of the aircraft through motion of internal masses within the aircraft. Prior research investigated the feasibility and benefit of internal mass-actuation in airplane control based on simulation analysis. The main focus of …

Numerical Studies On Spin Coating Of Metals, Varun Nanjunda Rao Viswamithra

Mechanical and Aerospace Engineering Theses - Archive

Spin coating is a surface coating process which involves spreading a liquid dispensed on the center of a rotating substrate. The liquid is discharged using a suitable method on to the substrate rotating at a constant angular speed. The spinning speed is controlled to obtain a coating of desired thickness with faster spinning resulting in thinner coating. The thickness of the coating also depends on the properties of the fluid and other process parameters. Centrifugal force is introduced into the code as radial component of acceleration. The first part of the code solves the continuity and the Navier-Stokes equations, with …

Cfd Analysis And Design Optimization Of Heat Sink For Oil Immersion Cooling, Koushik Epuri

Mechanical and Aerospace Engineering Theses - Archive

Air cooling is predominant cooling technique employed in most of the data centers. As the demand for High performance computing (HPC) which deploy large concentration of high-end servers (30 kW to 200 kW per rack) is increasing, it is becoming challenging to cool the systems using air cooling. Liquid cooling has significant advantages over air cooling techniques due to higher heat capacities of fluids. Liquid immersion cooling using dielectric and non-corrosive mineral oils is one of the potential alternative to air cooling methods for high density data centers. In this work, we consider a third generation open compute server optimized …

Design And Stiffness Optimization Of Quadri-Directional Composite Grid Lattice Structures, Gajendra Devanga Gangadara

Mechanical and Aerospace Engineering Theses - Archive

Composite grid structures are rib stiffeners connected to each other rigidly in a pattern or a lattice such that the whole grid pattern has certain smeared stiffness property and has a certain structural behavior. The main focus of this thesis is to design the geometric pattern of a Quadri-directional composite grid lattice such that it has the prescribed stiffness moduli. The research is divided into three phases, in the first phase, the equation for stiffness moduli, the reduced stiffness matrix [Q] and the laminate stiffness matrices [ABD] of the grid pattern is derived for Quadri-directional grid panels. In the second …

Crack Growth Mechanisms Under Anti-Plane Shear In Composite Laminates, Allison Lynne Horner

Dissertations - ALL

The research conducted for this dissertation focuses on determining the mechanisms associated with crack growth in polymer matrix composite laminates subjected to anti-plane shear (mode III) loading. For mode III split-beam test methods were proposed, and initial evaluations were conducted. A single test method was selected for further evaluation. Using this test method, it was determined that the apparent mode III delamination toughness, GIIIc, depended on geometry, which indicated a true material property was not being measured. Transverse sectioning and optical microscopy revealed an array of transverse matrix cracks, or echelon cracks, oriented at approximately 45° and intersecting the plane …

Resource Management For Distributed Estimation Via Sparsity-Promoting Regularization, Sijia Liu

Dissertations - ALL

Recent advances in wireless communications and electronics have enabled the development of low-cost, low-power, multifunctional sensor nodes that are small in size and communicate untethered in a sensor network. These sensor nodes can sense, measure, and gather information from the environment and, based on some local processing, they transmit the sensed data to a fusion center that is responsible for making the global inference. Sensor networks are often tasked to perform parameter estimation; example applications include battlefield surveillance, medical monitoring, and navigation. However, under limited resources, such as limited communication bandwidth and sensor battery power, it is important to design …

Novel Methods And Self-Reinforced Composite Materials For Assessment And Prevention Of Fretting Corrosion In Modular Tapers, Eric S. Ouellette

Dissertations - ALL

Novel methods for assessing the electrochemical and micromechanical performance of modular tapers were evaluated, and self-reinforced composite materials were developed for their potential to prevent the onset of mechanically assisted corrosion in modular taper devices.

A study of the seating and taper locking mechanics of modular taper samples was conducted, and the effect on taper engagement strength of seating load, loading rate, taper moisture, and taper design/material combination was studied. The load-displacement behavior was captured during seating, and the subsequent pull off load was correlated to seating displacement, seating energy, and seating load. The primary factor affecting taper engagement strength …

Uncovering And Mitigating Unsafe Program Integrations In Android, Xiao Zhang

Dissertations - ALL

Android’s design philosophy encourages the integration of resources and functionalities from multiple parties, even with different levels of trust. Such program integrations, on one hand, connect every party in the Android ecosystem tightly on one single device. On the other hand, they can also pose severe security problems, if the security design of the underlying integration schemes is not well thought-out. This dissertation systematically evaluates the security design of three integration schemes on Android, including framework module, framework proxy and 3rd-party code embedding. With the security risks identified in each scheme, it concludes that program integrations on Android are unsafe. …

Containment And Dewatering Of Heavy Metal Contaminated Sediments Using Reactive Soil Minerals And Cellulose Materials, Prabesh Rupakheti

Dissertations - ALL

The aim of this study is to investigate effective and sustainable measures to contain heavy metal contaminated sediments inside a geotextile tube during dewatering process. The efficacy of cellulosic materials (Jute fibers, Peanut hull, and Kraft pulp) on adsorption of selected heavy metals (Pb2+, Cu2+, Zn2+, and Cd2+) and dewatering performance inside a geotextile tube was studied by a series of Batch Adsorption and Pressure Filtration tests (PFT). The cellulosic materials were chosen keeping in mind their cost, accessibility, ease of handling and use, and sustainability. The studied adsorbents are inexpensive, easily available, and sustainable. In order to understand the …

Intentio Ex Machina: Android Intent Access Control Via An Extensible Application Hook, Carter Yagemann

Dissertations - ALL

Android's intent framework facilitates binder based interprocess communication (IPC) and encourages application developers to utilize IPC in their applications with a frequency unseen in traditional desktop environments. The increased volume of IPC present in Android devices, coupled with intent's ability to implicitly find valid receivers for IPC, bring about new security challenges to the computing security landscape.

This work proposes Intentio Ex Machina (IEM), an access control solution for Android intent IPC security. IEM separates the logic for performing access control from where the intents are intercepted by placing an interface in the Android framework. This allows the access control …

Wireless Power Transfer For Medical And Industrial Applications, Minh Quoc Nguyen

Electrical Engineering Dissertations - Archive

My primary research focuses on wireless power transfer technology utilizing in two different areas: medical and industrial applications. In the medical applications, my research focuses on design and optimization methods for spiral coils utilized for wireless power transfer in wireless medical implant applications. A theoretical model was examined for near field distributions of spiral-type transmitter antennas in both orthogonal components. Finite element simulations were performed to verify the theoretical radiation patterns. Receiver antenna voltages were measured at planes of interest as a means to map field distributions. Theoretical, simulation and experimental results were conducted in the free space and they …

Cfd Model For Ventilation In Broiler Holding Sheds, Christian Heymsfield

Biological and Agricultural Engineering Undergraduate Honors Theses

Broiler production in Arkansas was valued at over $3.6 billion in 2013 (University of Arkansas Extension of Agriculture). Consequently, improvement in any phase of the production process can have significant economic impact and animal welfare implications. From the time poultry leave the farm and until they are slaughtered, they can be exposed to harsh environmental conditions, both in winter and in summer. After road transportation, birds are left to wait in holding sheds once they arrive at the processing plant, for periods of approximately 30 minutes to two hours. This project was interested in this holding shed waiting time during …

Crizotinib And Ceritinib Induce Apoptosis And Necrosis In Primary Rat Hepatocytes With Distinct Capacity, Alec T. Salminen

Biomedical Engineering Undergraduate Honors Theses

Drug development makes up a major portion of biomedical engineering research interests. The FDA oversees the introduction, experimentation, and implementation of all drugs before market approval is granted. Even after market approval is granted, the FDA continues to monitor the safety of all drugs. Crizotinib and ceritinib are two anaplastic lymphoma kinase (ALK) inhibitors recently approved by the FDA. Both drugs are indicated for treatment of non-small cell lung cancers (NSCLC) with abnormal ALK gene, and they are approved with a companion diagnostic test that determines ALK abnormality. Clinical trial data suggest that crizotinib and ceritinib can cause liver injury, …