Engineering Commons^™

An Investigation On The Resilience Of Long Short-Term Memory Deep Neural Networks, Christopher Vasquez

LSU Master's Theses

In a world of continuously advancing technology, the reliance on these technologies continues to increase. Recently, transformer networks [22] have been implemented through various projects such as ChatGPT. These networks are extremely computationally demanding and require cutting-edge hardware to explore. However, with the growing increase and popularity of these neural networks, a question of reliability and resilience comes about, especially as the dependency and research on these networks grow. Given the computational demand of transformer networks, we investigate the resilience of the weights and biases of the predecessor of these networks, i.e. the Long Short-Term (LSTM) neural network, through four …

Optimization Of The Self-Healing Efficiency Of Bacterial Concrete Using Impregnation Of Three Different Precursors Into Lightweight Aggregate, Omar Omar

LSU Master's Theses

Concrete is the most broadly used construction material; thus, developing sustainable concrete is essential to decrease greenhouse gas (GHG) emissions from concrete production. Implementation of self-healing concrete technologies is a promising approach to enhance the durability and sustainability of the transportation infrastructure. Among these technologies, bacterial concrete has the potential to seal microcracks through microbial induced calcite precipitation (MICP). Bacterial protection is essential to ensure the viability of this technology due to concrete’s harsh environment. Additionally, the success of this technology depends on the presence of an adequate mineral precursor compound and nutrient for the bacteria. As such, the main …

Image Analysis Methodology For Evaluating Coating Uniformity Of Drug-Coated Angioplasty Balloons, Allison Dobson Zieschang

LSU Master's Theses

Percutaneous transluminal balloon angioplasty (PTA) is a surgical procedure to treat peripheral artery disease, but restenosis causes suboptimal outcomes in many patients. Drug-coated angioplasty balloons (DCBs) were developed to reduce the risk of restenosis by delivering anti-proliferative drugs to the lesion. The efficacy of DCBs depends on factors like drug loading and drug release rate, both of which are directly impacted by the coating uniformity. This thesis evaluates the uniformity of DBCs using fluorescence microscopy, scanning electron microscopy (SEM), qualitative analysis, and an image processing algorithm. Uniformity was quantified by three measurements: histogram standard deviation, histogram percentage of coverage, and …

Calibration And Use Of S3f Sensor For Normal And Shear Stress Measurements In Soil, Hussein Alqrinawi

LSU Master's Theses

Innovative sensors can provide new capabilities to monitor and understand the behavior of soil, rock, and geo-structures and help geotechnical engineers make informed decisions about the construction and maintenance of geo-structures. This study introduced, calibrated, and validated one such sensor, the Surface Stress Sensitive Film (S3F) point sensor, for both normal and shear stress measurements in soil along the soil-structure interface. The measurements of S3F sensor rely on the deformation of an elastic film that is monitored by a floating element embedded in the elastic film. This sensor provides measurements of the 3D deformation of the film which are converted …

Numerical Flume For Wave Dissipation By Mangrove Prop Roots, Rebecca L. Schurr

LSU Master's Theses

Mangroves provide shorelines with many beneficial engineering services, including shoreline stabilization, wave attenuation, and damage mitigation during tsunami or tropical cyclone events. This research focuses on wave attenuation rates and drag coefficients, and how they are affected by mangrove prop roots. Previous lab research using a physical wave flume has quantified wave height decay and drag coefficients for synthetic mangrove forests and confirmed that attenuation does indeed increase as mangrove forest density increases. This research will use a 3D numerical flume model developed in Proteus, a Python package, to simulate prior physical model experiments. This work will attempt to validate …

Examining The Impact Of Different Street Lighting Schemes On Traffic Safety And Drivers’ Behaviors At Unsignalized Intersections, Hisham Mohamed Abdu Kunnah

LSU Master's Theses

Lack of visibility is one of the main challenges that significantly impact drivers’ ability to safely perform driving tasks at night especially at unsignalized intersections. Several prior studies indicated that lighting enhances nighttime traffic safety. Nevertheless, lighting is not mandatory at unsignalized intersections in many states including Louisiana. This study aimed to investigate if lack of lighting is a contributing factor that affects traffic safety at unsignalized intersections in Louisiana. In addition, this study strived to identify current lighting policies adopted by other states, examine if there are any low-cost countermeasures implemented by other states to improve nighttime visibility, and …

Deposition, Material Characterization, And Mechanical Testing Of Cr Containing Diamond-Like Carbon Films, Nicholas Anderson

LSU Master's Theses

A series of amorphous hydrogenated chromium containing diamond-like carbon films were deposited on 316 stainless steel substrates with a chromium interlayer through inductively coupled plasma assisted direct current magnetron sputtering. Details on the deposition process of these films are discussed. The film is characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, energy dispersive spectroscopy, and transmission electron microscopy. The coating hardness and indentation modulus is measured by instrumented nanoindentation. The coefficient of friction and the upper bound of the coating wear coefficient is measured using the pin-on-disk method. The fracture toughness of the diamond-like carbon film and a …

Cable Decoupling And Cable-Based Stiffening Of Continuum Robots, Parsa Molaei

LSU Master's Theses

Cable-driven continuum robots, which are robots with a continuously flexible backbone and no identifiable joints that are actuated by cables, have shown great potential for many applications in unstructured, uncertain environments. However, the standard design for a cable-driven continuum robot segment, which bends a continuous backbone along a circular arc, has many compliant modes of deformation which are uncontrolled, and which may result in buckling or other undesirable behaviors if not ameliorated. In this study, a detailed approach for using additional cables to selectively stiffen planar cable-driven robots without substantial coupling to the actuating cables is investigated. A mechanics-based model …

Improved Selectivity And Stability In Methane Dry Reforming By Atomic Layer Deposition Onto Ni-Ceo2-Zro2/Al2o3 Catalysts, Jonathan Lucas

LSU Master's Theses

The use of Ni in the dry reforming of methane (DRM) has been widely studied as a replacement for noble metal catalysts (Pt, Pd, Rh) due to Ni’s low cost compared to noble metals, its abundance, and the fact that its DRM activity is near that of noble metal catalysts. However, Ni has been shown to deactivate quickly under DRM conditions. Rare earth oxides such as CeO₂, or as CeO₂-ZrO₂ (CZO) are supports that improve both the activity and stability of Ni DRM systems due to their redox activity. However, this same activity is thought …

Characterizing And Modeling The Impact Photorepair Conditions Have On Parameters Governing The Regrowth Of Escherichia Coli After Uvc Irradiation, And Investigating Potential Mitigation Strategies, Andrea J. Martinez Ballen

LSU Master's Theses

Ultraviolet disinfection has been used to treat water and wastewater for decades. Previous studies highlight the significance of disinfection conditions and attempt to model bacterial regrowth behavior according to disinfection dosing parameters. The emergence of light-emitting diode (LED) technology provides the ability to further explore bacterial repair methods after UV disinfection, which has been a growing concern within the UV community. However, it is necessary to also consider post-disinfection conditions to model the regrowth patterns of bacterial organisms more accurately. By varying reactivation wavelengths, and their respective intensities, experiments using Escherichia coli ATCC 15597 revealed how these parameters impact the …

Motivators And Preferences Of Route Diversion During Roadway Incidents, Grace Cole

LSU Master's Theses

When confronted with congestion and delay, drivers often divert their route. Depending on factors like purpose, urgency, destination, route alternatives, type of disruption, and mode options, common diversionary options can range from changing departure time, route, and mode to canceling a trip altogether. One of the foundational building blocks of travel forecasting is traffic assignment, which is used to distribute trips over a network using complex algorithms to aggregately represent the desire of drivers to minimize travel time.

While these assignment models are backed by decades of research and observational experience, they are also limited by the fact that they …

A Data-Driven Multivariate Process Monitoring Platform For Knowledge Discovery And Model Building In Industrial Applications, Estelle E. Seghers

LSU Master's Theses

In industrial chemical manufacturing processes, the amount of raw data generated can add complexity in the analysis and understanding of the process dynamics. Being able to properly interpret this data can help improve plant operation, especially regarding safety and profitability. This research has culminated in FastMan-JMP, a platform proposed for monitoring of industrial processes and optimization of the offline data-driven model-building process as part of the process monitoring workflow. FastMan-JMP is a tool developed in Python to apply various data mining and machine learning techniques quickly and easily to better understand valuable patterns and hidden trends in process data. One …

A Simulation Study Of Surfactant/Foam Processes In Shallow Subsurface Remediation: Using Foams For Mobility Control Vs. Blockage, Betty Cepeda

LSU Master's Theses

Many shallow ex-situ and in-situ remediation treatments come from the contamination of underground soils and groundwater sources by organic hydrocarbon components called non-aqueous phase liquids (NAPLs). These contaminants, if leaking, can impose long-term threats causing environmental and health concerns. One of the versatile in-situ remediation techniques is using surfactant/foam processes that can overcome subsurface heterogeneity and improve NAPL removal.

This simulation study investigates surfactant/foam processes, especially focusing on two different roles of foams during the treatment: foams for “mobility control” vs. foams for “blocking”. The first is based on the actual operations carried out in the pilot-test site for 23 …

Anaerobic Toluene Biodegradation Potential At A Superfund Site Where Toluene Biosynthesis Was Observed, George Carson

LSU Master's Theses

At a Superfund site near Baton Rouge, LA, the subsurface injection of molasses has been used to stimulate anerobic reductive dechlorination of halogenated organic compounds (e.g., 1,2-dichloroethane and vinyl chloride) present in the groundwater. Following some molasses injections, temporary accumulation of toluene and p-cresol was observed in the groundwater. Accumulation of these aromatic hydrocarbons, which were not detected in the molasses, has been attributed to anaerobic biotransformation of the amino acids phenylalanine and tyrosine. Experiments reported here were conducted in support of an effort to determine if toluene biodegrading bacteria were present in the area where anaerobic toluene accumulation was …

Programming The Properties Of Branched Polymers Through Precision Architectures, Michael R. Dearman

LSU Master's Theses

The glass transition of branched polymers is determined by multiple structural parameters that dictate their inter- and intramolecular interactions, and ultimately, their molecular packing in the amorphous phase. Here we examined the impact of side chain length, backbone length, molecular weight composition, and topology on the glass transition behavior of bottlebrush polymers. Through examining precision bottlebrush polymer libraries (PBP, ĐSC = 1.0), we find the infinite molecular weight Tg is reached at a specific brush length after which the effect of the side-chain length dominates. Being a factor more dominant than the backbone, side-chain length affects the Tg of bottlebrush …

A Machine Learning Approach To Robotic Additive Manufacturing Of Uv-Curable Polymers Using Direct Ink Writing, Luis A. Velazquez

LSU Master's Theses

This thesis presents the design and implementation of a robotic additive manufacturing system that uses ultraviolet (UV)-curable thermoset polymers. Its design considers future applications involving free-standing 3D printing by means of partial UV curing and the fabrication of samples that are reinforced with fillers or fibers to manufacture complex-shape objects.

The proposed setup integrates a custom-built extruder with a UR5e collaborative manipulator. The capabilities of the system were demonstrated using Anycubic resin formulations containing fumed silica (FS) at varying weight fractions from 2.8 to 8 wt%. To fully cure the specimens after fabrication, a UV chamber was used. Then, measurements …

Enabling The Human Perception Of A Working Camera In Web Conferences Via Its Movement, Anish Shrestha

LSU Master's Theses

In recent years, video conferencing has seen a significant increase in its usage due to the COVID-19 pandemic. When casting user’s video to other participants, the videoconference applications (e.g. Zoom, FaceTime, Skype, etc.) mainly leverage 1) webcam’s LED-light indicator, 2) user’s video feedback in the software and 3) the software’s video on/off icons to remind the user whether the camera is being used. However, these methods all impose the responsibility on the user itself to check the camera status, and there have been numerous cases reported when users expose their privacy inadvertently due to not realizing that their camera is …

Improvements To The Automatic Calibration Of Digital Focusing Color Schlieren Systems, Robert C. Frazee

LSU Master's Theses

As a diagnostic method, Schlieren imaging offers the unique ability to visualize flows with a completely non-intrusive method. By visualizing small changes in the refractive index of a fluid, Schlieren imaging is able to visualize changes in temperature, pressure, and composition. While historic Schlieren methods have been limited to providing largely qualitative information, modern Schlieren methods are able to extract quantitative information from flow phenomena. This is possible through either Background Oriented Schlieren (BOS) or Digital Focusing Color Schlieren (DFCS) methods. While BOS is relatively flexible, it requires a large amount of computational effort to process each frame of captured …

Application Of Direct Feedback Tunable Diode Laser Absorption Spectroscopy Within A Hybrid Rocket Combustor, Connor Becnel

LSU Master's Theses

With interest in space travel and space-related science increasing in recent years, significant efforts to reduce the cost and increase the safety of rocket motors have become commonplace. Liquid rockets are currently the most commonly used system, but there is interest in the reduced complexity of hybrid rockets. For these hybrid rocket motors to become the norm, extensive research on their complex boundary layer combustion needs to be performed. Modeling these hybrid systems is of much interest to companies developing rocket motors; ultimately, small-scale experiments will help validate their behavior. This paper covers the application of a near-infrared tunable diode …

Phase Transitions And Photoluminescent Properties Of Anion-Engineered Y2o3, Maharram Jabrayilov

LSU Master's Theses

Rare earth doped metal oxides are widely employed as phosphor materials for white light LEDs (w-LEDs). The aim of this work is to engineer anionic sites of metal oxides, specifically, Y₂O₃, to investigate structural and luminescent properties relationships and energy transfer mechanisms between rare earth sensitizer and activator ions in different hosts.

A low temperature two-step hydrothermal/combustion method was employed to incorporate sulfate ions into Y₂O₃. Furthermore, annealing at 600 °C under H₂/N₂ was employed to convert Y₂O₂SO₄ to Y₂O₂S. …

Device Free Indoor Localization Of Human Target Using Wifi Fingerprinting, Prasanga Neupane

LSU Master's Theses

Indoor localization of human objects has many important applications nowadays. Proposed here is a new device free approach where all the transceiver devices are fixed in an indoor environment so that the human target doesn't need to carry any transceiver device with them. This work proposes radio-frequency fingerprinting for the localization of human targets which makes this even more convenient as radio-frequency wireless signals can be easily acquired using an existing wireless network in an indoor environment. This work explores different avenues for optimal and effective placement of transmitter devices for better localization. In this work, an experimental environment is …

Using 2d Hec-Ras Modeling With Vertical Feature Extraction To Inform Ecological Design In The Lower Atchafalaya River Basin, Louisiana, Colin Anderson

LSU Master's Theses

A 2D HEC-RAS model was created to demonstrate applications of hydraulic modeling for informing ecological design. This was done by comparing the hydrologic conditions of a baseline year (2010) to that of the environmental flow prescription from Kozak et al. (2016). The inundation results are relevant to hydraulic connectivity and cypress regeneration.

The hydraulic model was created by assimilating numerous data sources, refining the model with vertical feature (VF) extraction, and calibrating/validating the model. Several topo-bathymetric sources were combined to create the digital elevation model (DEM). Most importantly, this included bathymetry of the backswamp. Polylines of significant VFs in the …

Evaluating Serverless Computing, Charitra Maharjan

LSU Master's Theses

Function as a Service (FaaS) is gaining admiration because of its way of deploying the computations to serverless backends in the different clouds. It transfers the complexity of provisioning and allocating the necessary resources for an application to the cloud providers. The cloud providers also give an illusion of always availability of resources to the users. Among the cloud providers, AWS serverless platform offers a new paradigm for developing cloud applications without worrying about the underlying hardware infrastructure. It manages not only the resource provisioning and scaling of an application but also provides an opportunity to reimagine the cloud infrastructure …

Electric Field Driven Co-Assembly And Transport Of Colloids Using Active-Passive Interaction, Brishty Deb Choudhury

LSU Master's Theses

Over the past few decades, the out-of-equilibrium transport and assembly of colloidal particles have been drawing significant interest due to their myriad applications in biology, engineering, and physics. In the absence of any external force, micro and nanoparticles perform Brownian motion in dispersion and are termed as passive colloids. In contrast, active colloids are a class of particles where a net imbalance of fluid flow around their surface drives their net migration in space when subjected to an external electric field. While several studies have shown the ability to program the dynamics of active colloids using an external electric field, …

Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot

LSU Master's Theses

Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …

Control And Planning For Mobile Manipulators Used In Large Scale Manufacturing Processes, Joshua T. Nguyen

LSU Master's Theses

Sanding operations in industry is one of the few manufacturing tasks that has yet to achieve automation. Sanding tasks require skilled operators that have developed a sense of when a work piece is sufficiently sanded. In order to achieve automation in sanding with robotic systems, this developed sense, or intelligence, that human operators have needs to be understood and implemented in order to achieve, at the minimum, the same quality of work. The system will also need to have the equivalent reach of a human operator and not be constrained to a single, small workspace. This thesis developed solutions for …

Predictive Thermal Modeling And Characterization Of Ultrasonic Consolidation Process For Thermoplastic Composites, Madeline Kirby

LSU Master's Theses

Ultrasonic consolidation (USC) of thermoplastic composites (TPCs) is a highly attractive and promising method to manufacture high-performance composites. This work focuses on USC of dry carbon fiber (CF) fabrics with high-temperature polyphenylene sulfide (PPS) films. Experimental trials to assess feasibility of the process are time-consuming. Consequently, a predictive thermal model would facilitate process parameters selection to reduce expensive trial-and-error approaches. This paper presents a 2D finite element model of samples under consolidation, incorporating equations for viscoelastic heating, matrix phase change, and material properties. Theoretical temperature profiles for nodes of interest were compared to the corresponding experimental temperature curves for various …

Neural Networks For Interference Mitigation In Satellite Communication Systems, Martha E. Cash

LSU Master's Theses

The objective of this thesis is to utilize the power of machine learning to develop a neural network-aided receiver in a DVBS-2X satellite communication system to improve the downlink transmission quality in the presence of interference. An emphasis is placed on mitigating the effects caused by non-linear distortions, carrier frequency offset, and additive white Gaussian noise. This thesis proposes a feed-forward neural network with two hidden layers to compensate for the distortions in the received signal. The proposed system model uses 16-APSK modulation scheme. The neural network is tested under varying degrees of non-linear distortion, frequency offsets, and varying levels …

Tunable Passive Shock And Vibration Isolators For Rotational Isolation, Chase B. Lemaire

LSU Master's Theses

Shock and vibration isolation are a critical need in helmets, which are widely used to protect athletes, workers, soldiers, and astronauts. Passive vibration isolation systems are a good option when mass and volume should be minimized and when the experienced loadings can be predicted. However, it is frequently challenging to find materials and structures which exhibit the optimal vibration and impact isolation properties for an application. As a case study illustrating a novel design paradigm for rotational shock absorption, a family of optimal solutions for the physical properties of American football helmets is presented. Lumped parameter Simulink models simulate a …

Scale Up Of A Novel Method To Maximize Malonyl-Coa In Escherichia Coli, Clifford Harris Leblanc Iv

LSU Master's Theses

The instability of oil’s price along with its limited availability and impact on the environment motivate the search for an alternative feedstock that can sustain the profitability of chemical companies. Industrial biotechnology can promote renewable sources of energy and products by using microorganisms to produce a wide range of chemical compounds. The three-carbon metabolite, malonyl-CoA, can serve as a precursor to a variety of industrial chemicals. The major hurdle with using malonyl-CoA in industry is that its intracellular concentration in Escherichia Coli is very low. Previous attempts to increase the intracellular level of malonyl-CoA have ranged from genetic engineering of …