Engineering Commons^™

Automation Of Data Collection From An Anechoic Chamber, Thomas S. Garner

Electronic Theses and Dissertations

This paper describes the calibration methods and the process that is used on the Ole Miss electrical engineering anechoic chamber. Furthermore the MATLAB code that operates the anechoic chamber has been updated to collect sweep data. The GUI also now includes a tab for calibration giving the user the ability to calibrate for their desired frequency range for when there is not sufficient calibration data already available.

Decentralized Detection With Correlated Gaussian Observations: Parallel And Tandem Networks With Two Sensors, Shailee Yagnik

Electronic Theses and Dissertations

Signal detection in cognitive radio involves the determination of presence or absence of a primary user signal so that the secondary user may opportunistically gain access when the spectrum is unoccupied. In decentralized sensing scheme, two or more secondary users sense the spectrum, process individual observation and then pass the quantized data to a fusion center where a decision with regard to which hypothesis being true, that is, a signal being present or absent, is made. In the second part of the thesis, we study Bayes error performance of two-sensor tandem network designed to detect the presence or absence of …

Decoding And Optimizing Magnesium Phosphate Binders For Additive Construction Applications, Hashem Khaled Almashaqbeh

Electronic Theses and Dissertations

This work aims to give more insight about the physical, mechanical, thermal, and chemical performance of the MPC paste composites. Our primary outcome from this research is to improve the MPC composites with different additives, including boric acid, GnP, and acetic acid for potential utilization in 3DcP applications. Furthermore, Martian and Lunar regolith simulants can be mixed with the MPC composites to create mortars as a possible extraterrestrial 3DP in-situ construction material mainly to support the NASA habitation exploration mission.

Utilizing Of Magnesium Oxysulfate Binders For Additive Construction Applications, Hatem Hashem Al-Masaeid

Electronic Theses and Dissertations

This dissertation is serving multiple transdisciplinary top-notch material design and technological topics. It is a proof of concept of the feasibility of 3D printing using Magnesium Oxysulfate (MOS) binder as an alternative to the ordinary Portland cement (OPC) to be utilized in terrestrial and extraterrestrial additive construction (AC) fields. MOS paste and mortar are characterized physically, chemically, and mechanically. The characterization results conducted in this research show how MOS’s properties can be controlled to match the 3D printing requirements by manipulating the MOS’s ingredients proportions.

Damage Detection Using Destructive Testing Of A Reinforced Concrete Slab, Michael Edward Daves

Electronic Theses and Dissertations

Visual inspection is one of the primary tools for evaluating the health of bridges as more reach or exceed their intended lifespan. Bridge deterioration must be monitored to ensure continued safety, so owners need maintenance reports to decide on corrective actions. Strategic repair can offer asset managers the benefit of saving money and time; thus, knowing where to locate and what type of repairs can be challenging when relying on visual techniques alone. A tool designed to aid bridge inspectors is the SHE^tm program, which quantitatively measures damage location and severity for any set of time data.

Investigating The Use Of Passive Acoustics As A Surrogate Method Of Monitoring Coarse Bedload Transport In Rivers And Streams Via Laboratory Experiments And Field Studies, Bradley Goodwiller

Electronic Theses and Dissertations

The movement of coarse gravel in rivers in streams is important for many applications including wildlife habitation, river morphology, infrastructure maintenance and marine navigation. Physical sampling remains the most accurate method of determining coarse bedload transport but it can be expensive, dangerous and flow intrusive. Surrogate methods of monitoring bedload transport is an active area of research worldwide. One such method is the use of passive acoustics to record the sound generated when gravel particles in motion impact each other or the particles on the bed. This dissertation presents research and development that has been conducted on three key areas …

Fabrication And Characterization Of Nonlinear Optical Ceramics For Random Quasi-Phase-Matching, Xuan Chen

Electronic Theses and Dissertations

A number of technologies rely on the conversion of short laser pulses from one spectral domain to another. Efficient frequency conversion is currently obtained in ordered nonlinear optical materials and requires a periodic spatial modulation of their nonlinear coefficient which results in a narrow bandwidth. One can trade off efficiency for more spectral bandwidth by relaxing the strict phase-matching conditions and achieve nonlinear interaction in carefully engineered disordered crystalline aggregates, in a so-called random quasi-phase-matching (rQPM) process. In this dissertation, we examine appropriate fabrication pathways for (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) and ZnSe transparent ceramics for applications in the mid-IR. The main challenge …

Numerical Investigation And Optimization Of Pin Fins In Micro Heat Sinks, Fuad Ismayilov

Electronic Theses and Dissertations

Operating temperature in electronics applications is continuously increasing. Therefore, for the past few decades, high heat flux removing micro heat sinks are investigated in terms of heat transfer effectiveness. This study generally concentrates on improving the passive heat transfer techniques. Micro heat sinks used in experiments are fabricated using MEMS techniques. Resistance temperature detectors, RTDs, were used for temperature measurements. The experimental data was obtained for single and two phase flow regions; however, only single phase flow results were considered in numerical simulations. Numerical validations were performed on the micro heat sinks, including cylinder and hydrofoil shaped pin fins. Following …

Mode Coupling In Space-Division Multiplexed Systems, Huiyuan Liu

Electronic Theses and Dissertations

Even though fiber-optic communication systems have been engineered to nearly approach the Shannon capacity limit, they still cannot meet the exponentially-growing bandwidth demand of the Internet. Space-division multiplexing (SDM) has attracted considerable attention in recent years due to its potential to address this capacity crunch. In SDM, the transmission channels support more than one spatial mode, each of which can provide the same capacity as a single-mode fiber. To make SDM practical, crosstalk among modes must be effectively managed. This dissertation presents three techniques for crosstalk management for SDM. In some cases such as intra-datacenter interconnects, even though mode crosstalk …

Fluid Flow Characteristics Of A Co-Flow Fluidic Slot Jet Thrust Augmentation Propulsion System, Brian Garrett

Electronic Theses and Dissertations

The UAV industry is booming with investments in research and development on improving UAV systems in order to increase applications and reduce costs of the use of these machines. Current UAV machines are developed according to the quadcopter design which has a rotary propulsion system which provides the lift needed for the aerial vehicles. This design has some flaws; namely safety concerns and noise/vibration production both of which come from the rotary propulsion system. As such, a novel propulsion system using slip stream air passed through high performance slot jets is proposed and analysis of the fluid characteristics is presented …

A Study Of Organo-Phosphorous Simulants Thermal Destruction Using Shock Tube/Laser Diagnostics Techniques And Chemical Kinetics Modeling, Sneha Neupane

Electronic Theses and Dissertations

High-fidelity chemical kinetic models are critical in predictive modeling during design and optimization of next generation energy systems. Shock tube provides an ideal tool to investigate high-temperature chemical kinetics. Non-intrusive laser absorption diagnostics provide in-situ measurements of quantitative, time-resolved species concentration data in this complex chemically reacting system. In this work, shock tube and laser absorption spectroscopy were utilized to measure species concentration time-histories during pyrolysis and oxidation of organo-phosphorous compounds (OPCs). The experiments data obtained were used as benchmark to develop an improved kinetic model of OPCs combustion. Interest in combustion chemistry of OPCs is associated to their use …

Instance Segmentation And Object Detection In Road Scenes Using Inverse Perspective Mapping Of 3d Point Clouds And 2d Images, Chungyup Lee

Electronic Theses and Dissertations

The instance segmentation and object detection are important tasks in smart car applications. Recently, a variety of neural network-based approaches have been proposed. One of the challenges is that there are various scales of objects in a scene, and it requires the neural network to have a large receptive field to deal with the scale variations. In other words, the neural network must have deep architectures which slow down computation. In smart car applications, the accuracy of detection and segmentation of vehicle and pedestrian is hugely critical. Besides, 2D images do not have distance information but enough visual appearance. On …

A Seed Dormancy Gene-Mediated Biotechnology To Mitigate Transgene Flow Into Weedy Rice, Luai Nahar Muhammad

Electronic Theses and Dissertations

Transgene flows into wild/weedy relatives may cause ecological and economic problems. Seed dormancy is an adaptive trait that distributes germination over time and promotes persistence of weeds in agroecosystems. Silencing natural genes controlling seed dormancy (SD) could promote germination and reduce weed adaptability. The goal of this project was to develop a transgenic mitigation (TM) technology by linking to a primary transgene with an SD gene-silencing structure, as a tandem construct for transformation, to reduce the risk of gene flow into weed populations. In this research, the Bar (Bialaphos) gene for resistance to the glufosinate herbicide was used as a …

Design And Investigation Of Genetic Algorithmic And Reinforcement Learning Approaches To Wire Crossing Reductions For Pnml Devices, Alexander Keith Gunter

Electronic Theses and Dissertations

Perpendicular nanomagnet logic (pNML) is an emerging post-CMOS technology which encodes binary data in the polarization of single-domain nanomagnets and performs operations via fringing field interactions. Currently, there is no complete top-down workflow for pNML. Researchers must instead simultaneously handle place-and-route, timing, and logic minimization by hand. These tasks include multiple NP-Hard subproblems, and the lack of automated tools for solving them for pNML precludes the design of large-scale pNML circuits.

Evaluating The Use Of Suas-Derived Imagery For Monitoring Flood Protection Infrastructure, Eleanor Mei Dietz

Electronic Theses and Dissertations

In the US there are approximately 33,000 miles of levees. This includes 14,500 miles of levee systems associated with US Army Corps of Engineers programs and approximately 15,000 miles from other state and federal agencies. More than 14 million people live behind levees and associated flood prevention infrastructure. Monitoring and risk assessment are an on-going process, especially during times of flood conditions. The city of New Orleans was heavily impacted by Hurricane Katrina in 2005 by storm surges and intense rainfall. The impact of the hurricane was substantial enough to cause levee failure and I-wall toppling where many of the …

Raptor Codes For Biawgn Channel: Snr Mismatch And The Optimality Of The Inner And Outer Rates, Hussein Fadhel

Electronic Theses and Dissertations

Fountain codes are a class of rateless codes with two interesting properties, first, they can generate potentially limitless numbers of encoded symbols given a finite set of source symbols, and second, the source symbols can be recovered from any subset of encoded symbols with cardinality greater than the number of source symbols. Raptor codes are the first implementation of fountain codes with linear complexity and vanishing error floors on noisy channels. Raptor codes are designed by the serial concatenation of an inner Luby trans-form (LT) code, the first practical realization of fountain codes, and an outer low-density parity-check (LDPC) code. …

Magnetic Amphiphiles And Their Potential Applications For Low Energy Separations Processes, Alexander Fortenberry

Electronic Theses and Dissertations

Predicting the behavior of magnetic surfactants in magnetic fields is critical for designing magnetically driven processes such as chemical separations or the tuning of surface tensions. Our work supports the hypothesis that the ability of magnetic fields to alter the interfacial properties of magnetic surfactant solutions depends on the strength of association between the magnetic and surfactant moieties of the surfactant molecules. Our research shows that the stability of a magnetic surfactant in an aqueous environment is dependent upon the type of complex that contains the paramagnetic element and these findings provide valuable insight for the design of magnetic surfactants …

Investigative Study Of Poly(Ionic) Liquid Incorporation In Resin Wafer Electrodeionization For Improved Specific Energy Consumption, Angela Fasuyi

Electronic Theses and Dissertations

An electrokinetic separation method known as Resin Wafer Electrodeionization (RW-EDI) is recognized as a promising technology for energy efficient desalination of brackish water. However RW-EDI is limited by an inherent drawback of its ion exchange media that prevents the largescale deployment of this technology. This research was undertaken to optimize the conventional resin wafer used in RW-EDI through the incorporation of high conducting polyionic liquids (PILs). It was hypothesized that by the changing non-conducting polyethylene binder with a PIL binder in conventional resin wafer configurations ion conductivity within the resin bed would be enhanced and could lead to an improvement …

Molecular Dynamics Study Of Sintering Behavior Of Single-Crystal, Bimetallic Core/Shell Alloy, And Intermetallic Alloy Nanoparticles, Jungmin Jeon

Electronic Theses and Dissertations

There has been rapidly growing interest in the sintering process of nanoparticles (NPs) among academia and modern industry due to their promising applications in additive manufacturing (AM) based on the overall improved properties at nanoscale. In the past decade a lot of experimental and computational work has been conducted to study the sintering process of powder materials. However there is still a significant knowledge gap in a fundamental understanding of the thermodynamics and nanostructural evolution of NPs undergoing additive manufacturing. This thesis aims to gain fundamental insights into melting behavior of different materials including single-crystal bimetallic core/shell alloy and intermetallic …

Developing A Calibrated Seepage Meter To Measure Stream-Aquifer Interaction In The Mississippi Delta, Wesley J. Bolton

Electronic Theses and Dissertations

The Mississippi Alluvial Plain (MAP) is a premier region for irrigated agriculture in the United States producing approximately 9 billion dollars in annual revenues. The region receives around 138 cm of precipitation annually; however irrigation is necessary to maximize crop yields as most of the precipitation does not occur during the growing season. There are 8 million irrigated acres within the Mississippi Alluvial Plain. The source of most of the irrigated water is the surficial aquifer in the Mississippi Embayment the Mississippi River Valley Alluvial Aquifer (MRVAA) and due to the reliance on irrigation for maximum crop yields recent potentiometric …

Experimental And Numerical Investigation Of A Novel Adsorption Bed Design For Cooling Applications, Ramy H. Mohammed

Electronic Theses and Dissertations

A global challenge is to develop environmentally friendly, affordable, compact and sustainable technologies to provide heating and cooling power. Adsorption cooling (AC) technology is one of the most promising ways to solve the environmental issues and cut down the energy consumption related to the traditional air conditioning and refrigeration systems. However, AC systems still suffer from poor heat and mass transfer inside the adsorption bed, which is the main obstacle to commercialization of adsorption cooling units. The main goal of this study is designing an efficient adsorption cooling cycle. In this research work, an in-depth scaling analysis of heat and …

Ultra-High Performance Concrete For Precast Seismic Bridge Column Connection, Titchenda Chan

Electronic Theses and Dissertations

Accelerated bridge construction (ABC) utilizes prefabricated bridge elements constructed off-site, delivered, and assembled on-site to expedite construction time and reduce traffic disruption. ABC has been increasingly used for super- and sub-structure elements in low seismic regions. However, its application in medium and high seismic regions remain limited, particularly for precast columns where connections typically coincide with plastic hinge (PH) regions. Ultra-high performance concrete (UHPC), characterized by high compressive and tensile strength, and superior bond properties, is a potential material that can mitigate PH damage and enhance load transfer. This research proposes a new and simple damage tolerant precast column connection …

Broadband Mid-Infrared Frequency Combs Generated Via Frequency Division, Qitian Ru

Electronic Theses and Dissertations

Frequency combs have revolutionized metrology and demonstrated numerous applications in science and technology. Combs operating in the mid-infrared region could be beneficial for molecular spectroscopy for several reasons. First, numerous molecules have their spectroscopic signatures in this region. Furthermore, the atmospheric window (3-5μm and 8-14μm) is located here. Additionally, a mid-infrared frequency comb could be employed as a diagnostic tool for the many components of human breath, as well as for detection of harmful gases and contaminants in the atmosphere. In this thesis, I used synchronously pumped subharmonic optical parametric oscillators (OPOs) operating at degeneracy to produce ultra-broadband outputs near …

Investigation Of Ps-Pvd And Eb-Pvd Thermal Barrier Coatings Over Lifetime Using Synchrotron X-Ray Diffraction, Matthew Northam

Electronic Theses and Dissertations

Extreme operating temperatures within the turbine section of jet engines require sophisticated methods of cooling and material protection. Thermal barrier coatings (TBCs) achieve this through a ceramic coating applied to a substrate material (nickel-based superalloy). Electron-beam physical vapor deposition (EB-PVD) is the industry standard coating used on jet engines. By tailoring the microstructure of an emerging deposition method, Plasma-spray physical vapor deposition (PS-PVD), similar microstructures to that of EB-PVD coatings can be fabricated, allowing the benefits of strain tolerance to be obtained while improving coating deposition times. This work investigates the strain through depth of uncycled and cycled samples using …

Hurricane Imaging Radiometer (Hirad) Tropical Rainfall Retrievals, Abdusalam Alasgah

Electronic Theses and Dissertations

The Hurricane Imaging Radiometer (HIRAD) is an airborne passive microwave remote sensor, developed to measure wind speed and rain rate in hurricanes. This dissertation concerns the development of a signal processing algorithm to infer tropical rainfall from HIRAD radiance (brightness temperature, Tb) measurements. The basis of the rain rate retrieval algorithm is an improved forward microwave radiative transfer model (RTM) that incorporates the HIRAD multi-antenna-beam geometry, and uses semi-empirical coefficients derived from an airborne experiment that occurred in the Gulf of Mexico off Tampa Bay in 2013. During this flight, HIRAD observed a squall line of thunderstorms simultaneously with an …

Artificial Magnetism And Topological Phenomena In Optics, Midya Parto

Electronic Theses and Dissertations

Recent years have witnessed intense research activities to effectively control the flow of photons using various classes of optical structures such as photonic crystals and metamaterials. In this regard, optics has benefited from concepts in condensed matter and solid-state physics, where similar problems concerning electronic wavefunctions arise. An important example of such correspondence is associated with the photon dynamics under the effect of an artificial magnetic field. This is especially important since photons, as neutral bosons, do not inherently interact with magnetic fields. One way to mitigate this issue is to exploit magneto-optical materials. However, as is well known, using …

The Relative Contribution Of Fixation Features, Activity, And Tibiofemoral Conformity On Initial Stability Of Cementless Tibial Trays, James Sullivan Deacy

Electronic Theses and Dissertations

Initial stability of cementless total knee replacements (TKR) is critical to implant success as excessive motion between the bone and implant prevents bony ingrowth that is critical to the long-term survivability of cementless implants. Prior studies have shown that excessive micromotion causes fibrous tissue growth instead of beneficial bony growth. There are many factors that influence initial stability including the design of the tibial tray and the tibiofemoral articulations. Understanding the impacts of these design features on micromotion between the bone and implants is crucial to improving the performance of cementless TKR. Prior studies only tested for the effect of …

Knee Balance Assessment During Cementation Is Detrimental To Initial Tka Tibial Tray Fixation, Yashar Ali Behnam

Electronic Theses and Dissertations

Despite recent advancements in implant design and cement technique, aseptic tibial loosening remains the primary cause of revision after cemented total knee arthroplasty (TKA) [1]. While the mechanisms of tibial loosening are multifactorial, previous research has shown that third-generation cement techniques, including the use of jet lavage and cement pressurization, can reduce contamination of the implant surface by lipids endogenous to the surrounding cancellous bone and thereby enhance fixation strength between the implant and bone [2]. The purpose of this thesis is to understand the role contaminating lipids play in the mechanism of aseptic loosening and to perform a cadaveric …

Applied Deep Learning In Orthopaedics, William Stewart Burton Ii

Electronic Theses and Dissertations

The reemergence of deep learning in recent years has led to its successful application in a wide variety of fields. As a subfield of machine learning, deep learning offers an array of powerful algorithms for data-driven applications. Orthopaedics stands to benefit from the potential of deep learning for advancements in the field. This thesis investigated applications of deep learning for the field of orthopaedics through the development of three distinct projects.

First, algorithms were developed for the automatic segmentation of the structures in the knee from MRI. The resulting algorithms can be used to accurately segment full MRI scans in …

Laxity Of The Hip Capsule In Natural And Posteriorly Implanted Specimens, Luke Storer

Electronic Theses and Dissertations

The hip capsule consists of ligament tissue that surrounds the hip joint, providing stability to ensure proper alignment, prevent dislocation, and facilitate proper joint function. The objective of this study was to characterize the torque-rotation response of the natural and posteriorly implanted hip capsule in healthy cadaveric specimens in multiple degrees-of-freedom (DOF) and under combined loading scenarios using the AMTI VIVO, a robotic joint simulator. The anterior portion of the hip capsule was stained with Methylene Blue and virtual extensometers were calculated by Digital Image Correlation (DIC) software for Finite Element Analysis (FEA) model validation. The range of motion (ROM) …