Engineering Commons^™

Synthesis Of Polymer Structures For Increasing Energy Conversion In Solar Cells, Fu-Hao Chen

Dissertations - ALL

Solar cells are the mainstream of renewable energy, since solar energy is abundant and accessible to most places on Earth. However, it has drawbacks, such as low energy conversion commonly less than 20 %, the power supply is intermittent and not stable. In industry, the energy conversion efficiency versus cost is the first priority to promote. Thus, implementing low cost but effective technique is attractive to industry. Based on geometric and wave optics, two simple-integrated and scalable techniques to improve the energy conversion of solar cells are developed. The first method is to make a v-groove structure on the encapsulant, …

Use Of Computational Electromagnetics To Enhance The Accuracy And Efficiency Of Antenna Pattern Measurements, Heng Chen

Dissertations - ALL

The objective of this dissertation is to illustrate that computational electromagnetics can be used to improve the accuracy and efficiency of antenna pattern measurements.

This can be accomplished in many different ways, such as moving a single probe over the measurement plane to generate accurate planar near field to far field transformation methodology over the classical Fourier based modal expansion methods. Also, one can use an array of probes instead of moving a single probe over the measurement plane to eliminate the inaccuracy of a mechanical movement of the probe antenna over a large planar surface and make the measurement …

Wireless Electrostimulation To Eradicate Bacterial Biofilms, Hao Wang

Dissertations - ALL

Bacterial biofilms can form on medical implants and cause serious device-associated infections that are incurable by conventional antibiotics because of high-level tolerance to antimicrobials. Common strategies for controlling device-associated infections, such as coating with antimicrobials and modification of surface properties, can reduce or delay biofilm formation, but the inhibitory effect can be overcome by bacteria over time, and eradicating mature biofilms remains challenging. Direct currents (DCs) have been shown to have bactericidal effects and synergy with conventional antibiotics in concurrent treatment has been demonstrated for killing biofilm cells. However, these systems require a direct connection between electrodes and a power …

Composite Right-Left Handed Stripline Structures For Antenna Array Feed Networks, Michael Douglas Enders

Dissertations - ALL

In this dissertation composite right/left-handed striplines are proposed as viable key structures in antenna array applications, enabling reduction of the overall feed network sizes as well as allowing integration opportunities and possible reduction of radiating beam pattern distortions.

A via-less composite right/left-handed stripline unit cell is introduced as an option to attain right/left-handed performance in stripline with a via-less fabrication process that is not sensitive to drill positioning errors and is amenable to academic settings. An analysis of the passbands of this structure based on the distributed transmission line circuit theory is provided as well as a description of the …

Processing And Properties Of New Anisotropic And Mechanically Active Polymeric Composites, Matthew M. Ali

Dissertations - ALL

Electrospinning is a versatile and inexpensive method to fabricate micron-sized polymer fibers, and it has been employed in this work to develop highly anisotropic fibrous composites. Previous work has detailed the properties of using electrospinning to fabricate fibrous anisotropic composites that was achieved by embedding stiff fibers in an elastomeric matrix. The goal of this work is to achieve anisotropic composites through creating a layering of rigid and elastic fibers in a laminate structure using primarily electrospinning in the fabrication. The composite produced has a unique deformation pattern when strained perpendicularly. The rigid fibers experienced no entanglement with each other …

Computational Modeling Of Bacterial Outer Membranes And Development Of High-Throughput Screening Platform For Antibiotics, Huilin Ma

Dissertations - ALL

Antibiotic resistance is a major health challenge because it limits the treatment options for common infectious diseases and will cause 10 million deaths each year after 2050. There is an urgent need to reduce the misuse of antibiotics and seek new classes of antibiotics that induce less or no resistance. Despite the push for new therapeutics, there has been a precipitous decline in the number of newly approved antibacterial drugs due to a limited understanding of how bacteria adapt to the chemical stress stimuli. The development of antimicrobial resistance is especially true for Gram-negative bacteria that develop resistance to antibiotics …

Integrating Trustzone Protection With Communication Paths For Mobile Operating System, Kailiang Ying

Dissertations - ALL

Nowadays, users perform various essential activities through their smartphones, including mobile payment and financial transaction. Therefore, users’ sensitive data processed by smartphones will be at risk if underlying mobile OSes are compromised. A technology called Trusted Execution Environment (TEE) has been introduced to protect sensitive data in the event of compromised OS and hypervisor.

This dissertation points out the limitations of the current design model of mobile TEE, which has a low adoption rate among application developers and has a large size of Trusted Computing Base (TCB). It proposes a new design model for mobile TEE to increase the TEE …

Residual Flexural Strength Of Corroded Aashto Type Ii Pretensioned Concrete Girder-Deck System, Bo Yan

Dissertations - ALL

Precast-prestressed concrete (PC) girders are among the most cost-effective type of girders used on highway bridges. Unfortunately, in corrosive environments, corrosion of strands may result in cracking or spalling of concrete, cross-section loss of strands and degradation of material properties, which in turn reduces the load-carrying capacity of PC bridges.

This research presents an in-depth analysis of residual flexural strength of corroded AASHTO Type II pretensioned PC girders with a cast-in-place (CIP) concrete deck. The investigation involved development of a detailed Finite Element Analysis (FEA) model of the pretensioned girder-deck system subjected to corrosion. The FEA model developed for this …

Peppy: A Tool To Generate Bacterial Peptidoglycan Scaffolds For Coarse-Grained Simulations, Xichen Xu

Theses - ALL

Peptidoglycan (PG), also known as murein, is an essential component in both Gram-positive and Gram-negative bacteria. However, even if the chemical structure has been well-known for long, the great tertiary structure remains not clear due to its variability and complicated cross-link mechanism. And it inevitably raises the huge challenge for computational simulations. Against the background, here we present a method for building a solvated peptidoglycan system at coarse-grained level as required. The method is named PEPpy, which represents a Peptidoglycan python code. It reads in the user’s parameters in sequence and automatically generates a topological file and a structure file …

Dynamic Change Of Cardiomyocytes On Shape Memory Polymer, Shiyang Sun

Theses - ALL

In the previous work, it has been proven that substrate topography can influent the cell behaviors, including morphology and functions. Many research teams showed that wrinkled surfaces have been able to improve the alignment and orientation of different biological cell types. Cardiomyocytes are also influenced by the surface topography with better alignment along the winkles, comparing to the flat surface. However, there is little evidence to demonstrate how cardiomyocytes would respond to the wrinkle formation and achieve the cellular alignment change during the transition from flat surface to topographic surface. In this thesis, we have created a dynamic substrate based …

Doing A Lot With A Little: A Diagnostic Analysis Of Swmm To Simulate Hydrologic Behavior Within Lid Systems, Lucie Lynn Worthen

Theses - ALL

Low Impact Development (LID) aims to mitigate the hydrological impacts of urbanization by promoting evapotranspiration, storing and slowing the flow of water in formerly impervious areas. Green roofs, a form of LID often utilized in highly urbanized watersheds, are widely simulated using the Storm Water Management Model (SWMM). However, methods to improve diagnostic analysis of SWMM have lagged compared to other environmental disciplines. In this study, I utilize frugal diagnostic analyses to investigate potential sources of non-linearity, uncertainty, and equifinality within SWMM applied to a particular case study, the OnCenter green roof in Syracuse, New York. My findings highlight the …

Modern Methods In Machine Learning As Applied To The Study Of A Complex Supersonic Jet Flow, Andrew Steven Tenney

Dissertations - ALL

The desire for aircraft to fly higher, farther, and faster has led to the use of more complex nozzle geometries over the last several decades. These nozzles often take advantage of multiple high-velocity streams issuing from non-axisymmetric exit areas and can be optimized for airframe integration and stealth performance. The associated turbulent jet physics and the aeroacoustic phenomena have been studied thoroughly over the past 80 years; however, the complex non-linear interactions between multiple merging canonical flows are not well understood. In this study, we seek to gain a better understanding of the flow physics in the near-field of a …

High-Torque-Density Low-Cost Magnetic Gear Utilizing Hybrid Magnets And Advanced Materials, Ali Hussain Al-Qarni, Fan Wu, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

Two major challenges of existing high-performance magnetic gears are: (i) High content of rare-earth permanent magnets which results in high cost as well as price fluctuation; (ii) Conflict between mechanical and electromagnetic performances, especially in the design of highspeed rotor. A magnetic gear using a blend of magnet types, i.e NdFeB, or Dy-free NdFeB and ferrites, is proposed in this paper. The goal is to bring down the cost while retaining comparable torque-transducing performance to a baseline magnetic gear only using rare-earth NdFeB magnets. A variety of topologies based on different combinations of magnet types and geometric shapes have been …

Validation Of The State Based Peridynamic Lattice Model, Anima Bista

Civil Engineering ETDs

This thesis presents a study performed to validate the State-based Peridynamic Lattice Model (SPLM) using results obtained from laboratory experiments. The SPLM is capable of modeling cracking of solids using particle lattices. We use a plane stress, elastic-plastic damage SPLM model for the simulations. The SPLM model is appropriate for computational simulations of cementitious materials as it automatically allows cracks to develop. In this study, the lattices are rotated through different angles and the variations of the cracking patterns are studied. In the laboratory, we performed nine Brazilian split cylinder tests, three anchor pullout/direct tensile tests, and eight compression tests …

Quantification Of Sediment Yields From Semi-Arid Watersheds Using Unmanned Aerial Systems And Photogrammetry Techniques, Jared L. Romero

Civil Engineering ETDs

Sediment has long been considered an environmental pollutant, causing physical and ecological impairments linked to the detachment and transport of sediments from the land surface to downstream communities. Additionally, aging flood control and water storage detention facilities have suffered the effects of sediment accumulation, spurring new research in the field of soil erosion and sediment yield estimation. Recent advances in technology have stimulated the use of unmanned aerial systems (UAS) and photogrammetric techniques for near-surface data collection and monitoring, with such techniques being used previously to achieve centimeter-level accuracy reconstruction of the land surface. This study seeks to apply UAS …

Returns On Library Investment: A Study Of The Leading Engineering And Technology Institutes In India, Shivendra Singh, Ramesh Pandita Mr.

Library Philosophy and Practice (e-journal)

The study is based on the secondary data compiled by the Ministry of Human Resource & Development, Govt., of India for the period 2012-13, 2013-14 & 2014-15 and was released as the ranking list of Institutes of Engineering and Technology in India for the year 2016. The study aims to assess the Returns on Investment (ROI) of the twenty leading libraries of the Institutes of Engineering and Technology in India in the form of institutional research output. An attempted has also been made to rank the each individual library on the basis of seven different parameters chosen for the study …

Optimal And Efficient Decision-Making For Power System Expansion Planning, Mahdi Mehrtash

LSU Doctoral Dissertations

A typical power system consists of three major sectors: generation, transmission, and distribution. Due to ever increasing electricity consumption and aging of the existing components, generation, transmission, and distribution systems and equipment must be analyzed frequently and if needed be replaced and/or expanded timely. By definition, the process of power system expansion planning aims to decide on new as well as upgrading existing system components in order to adequately satisfy the load for a foreseen future.

In this dissertation, multiple economically optimal and computationally efficient methods are proposed for expanding power generation, transmission, and distribution systems. First, a computationally efficient …

Application Of X-Ray Grating Interferometry To Polymer/Flame Retardant Blends In Additive Manufacturing, Omoefe Joy Kio

LSU Doctoral Dissertations

X-ray grating interferometry is a nondestructive tool for visualizing the internal structures of samples. Image contrast can be generated from the absorption of X-rays, the change in phase of the beam and small-angle X-ray scattering (dark-field). The attenuation and differential phase data obtained complement each other to give the internal composition of a material and large-scale structural information. The dark-field signal reveals sub-pixel structural detail usually invisible to the attenuation and phase probe, with the potential to highlight size distribution detail in a fashion faster than conventional small-angle scattering techniques. This work applies X-ray grating interferometry to the study of …

A Model-Based Framework For The Smart Manufacturing Of Polymers, Santiago D. Salas Ortiz

LSU Doctoral Dissertations

It is hard to point a daily activity in which polymeric materials or plastics are not involved. The synthesis of polymers occurs by reacting small molecules together to form, under certain conditions, long molecules. In polymer synthesis, it is mandatory to assure uniformity between batches, high-quality of end-products, efficiency, minimum environmental impact, and safety. It remains as a major challenge the establishment of operational conditions capable of achieving all objectives together. In this dissertation, different model-centric strategies are combined, assessed, and tested for two polymerization systems.

The first system is the synthesis of polyacrylamide in aqueous solution using potassium persulfate …

Transfer Process With 2-Dimensional Transitional Metal Dichalcogenides Materials, William Huang

Journal of the Microelectronic Engineering Conference

No abstract provided.

Fabrication Of Sub-300nm Fins At Rit By Sadp, Kelly Weiskittel

Journal of the Microelectronic Engineering Conference

No abstract provided.

Depressiongnn: Depression Prediction Using Graph Neural Network On Smartphone And Wearable Sensors, Param Bidja

Honors Scholar Theses

Depression prediction is a complicated classification problem because depression diagnosis involves many different social, physical, and mental signals. Traditional classification algorithms can only reach an accuracy of no more than 70% given the complexities of depression. However, a novel approach using Graph Neural Networks (GNN) can be used to reach over 80% accuracy, if a graph can represent the depression data set to capture differentiating features. Building such a graph requires 1) the definition of node features, which must be highly correlated with depression, and 2) the definition for edge metrics, which must also be highly correlated with depression. In …

Using Wind And Hydro Power To Sustain The Off-Grid Power Supply For A 50' Cruising Sailboat, Keisha Meyer, Torrey J. Wagner, Jada Williams

Faculty Publications

Cruising sailboats operate with a power requirement modest enough to operate mostly or completely on renewable energy technology sources. Cruisers without renewable energy systems use the vessel’s diesel engine to charge the boat’s batteries; if the systems are operated at anchor, this dramatically decreases the time before the engine needs major overhaul. System users estimate a diesel engine can run approximately 8,000 hours underway before needing major overhaul, whereas operating 500 hours at anchor produces similar wear and tear on engine pistons. Although renewable energy systems have a high initial capital cost, these systems can provide the vessel’s electrical system …

Repurposing Plastic Waste In El Cercado, Joseph Dooling, Kirby Townsend, Brendan Smith

Honors Thesis

This project aims to assist the community of El Cercado in the Dominican Republic in turning their plastic waste into useful products. The design team developed a first iteration shredder, injector, and aluminum mold which future design teams could further iterate in order to make products out of waste plastic. Different products were researched to ensure that they can be sold or used in the community. The goal of producing these items is to stimulate economic activity in the community by creating economic opportunity. The design shall also be sustainable in three ways. It shall reuse plastic waste while also …

Algorithmic Multi-Color Cmos Avalanche Photodiodes For Smart-Lighting Applications, Md Mottaleb Hossain

Optical Science and Engineering ETDs

Future smart-lighting systems are expected to deliver adaptively color-tunable and high-quality lighting that is energy efficient while also offering integrated visible-light wireless communication services. To enable these systems at a commercial level, inexpensive and fast sensors with spectral-sensing capability are required. CMOS-compatible silicon avalanche photodiodes (APDs) can be an excellent fit to this problem due to their excellent sensitivity, high speeds and cost effectiveness; however, color sensing is a challenge without resorting to expensive spectral filters, as done in commercially. To address this challenge, we have recently designed and modeled a novel CMOS-compatible dual-junction APD. The device outputs two photocurrents …

Highly Flame-Retardant Rigid Polyurethane Foams Prepared Using Corn Oil, Camila Muliterno Zequine

Electronic Theses & Dissertations

One of the biggest catastrophic problems worldwide is the structural fire that destroys properties, durable goods and lives. Polyurethanes are one of the most important polymers because of the widely use in industrial applications, such as thermal insulation, coating, construction and automobiles. However, polyurethane foams have the disadvantage of being flammable. Most of the starting materials for the production of polyurethanes are derivate from petroleum-based resources, which generates environmental and governmental problems. In this study, bio-based rigid polyurethane foams were synthesized using corn oil. First, commercial corn oil was fully epoxidized to be used in the synthesis of flame-retardant rigid …

Synthesis And Characterization Of Corn Oil Based Polyol And Its Application For Rigid Flame Retardant Polyurethane Foams, Sneha Ramanujam

Electronic Theses & Dissertations

A novel bio-based polyol was synthesized using corn oil and 2-mercaptoethanol via thiol-ene reaction as an alternative to petroleum-based polyol for the synthesis of polyurethane foams. The polyol was analyzed using wet chemical techniques to obtain a hydroxyl number and the viscosity of the polyol. Infrared spectroscopy and gel permeation chromatography were used to confirm the structural properties of the foams. Flame-retardant polyurethane foams were prepared by the addition of different concentrations of dimethyl methyl phosphonate (DMMP) in the final foam composition. The effect of DMMP on the thermo-mechanical properties of the polyurethane foams was analyzed. The TGA analysis showed …

The Critical Difference Seismic Design Can Make For A Reinforced Concrete Building Located In Oxford, Mississippi, Naim Daghmash

Honors Theses

The Senior Design course at the University of Mississippi requires the completion of a capstone project. One part of the capstone project is a complete structural design of the NOLA, an ongoing construction in the city of Oxford in Mississippi. The course requires the NOLA to be designed according to gravity loads, meaning the forces act in the downward direction towards the earth’s surface. Some loading mechanisms that could occur in a different direction than gravity are seismic loads, which are earthquake-generated loads. I was not required by my instructors to consider the effect of an earthquake on the structural …

How Av Could Shape Our Cities - Research From The Netherlands, Gonçalo H. A. Correia

PSU Transportation Seminars

Automated driving has become a hot topic of research in different fields of science. Despite the great advancements in the vehicle technology itself, researchers are now concerned in figuring out what will be the impacts of these vehicles in life as we know it. These impacts can be rather broad from traffic safety to the economy. In this lecture, Goncalo will focus on the research that is being done at TU Delft, a leading university in automated vehicles’ (AVs) impacts research, focusing on urban areas and how mobility, and even the city itself, can change with fully-automated vehicles. Goncalo Correia …

Forward Osmosis Flow Rate Differential Using Different Osmotic Agents, John M. Trzinski

Beyond: Undergraduate Research Journal

Life support is one of the most vital systems flown on manned spaceflight missions. The systems currently used are large, heavy, inefficient, and power consuming in an environment that requires nearly perfect conditions to function. Forward Osmosis (FO) is a form of filtration that uses the natural properties of water and concentration gradients to filter water without the need for any electricity. An experiment was conducted during the Embry Riddle Summer 2018 study abroad to the LUNARES research station in Piła, Poland. This experiment explored how the flow rate of water through a FO filtration system could be affected by …