Engineering Commons^™

Fatigue-Crack Detection And Monitoring Through The Scattered-Wave Two-Dimensional Cross-Correlation Imaging Method Using Piezoelectric Transducers, Wenfeng Xiao, Lingyu Yu, Roshan Joseph, Victor Giurgiutiu

Faculty Publications

Piezoelectric transducers are convenient enablers for generating and receiving Lamb waves for damage detection. Fatigue cracks are one of the most common causes for the failure of metallic structures. Increasing emphasis on the integrity of critical structures creates an urgent need to monitor structures and to detect cracks at an early stage to prevent catastrophic failures. This paper presents a two-dimensional (2D) cross-correlation imaging technique that can not only detect a fatigue crack but can also precisely image the fatigue cracks in metallic structures. The imaging method was based on the cross-correlation algorithm that uses incident waves and the crack-scattered …

Leaching Kinetics Of Rare Earth Elements From Fire Clay Seam Coal, Xinbo Yang, Rick Q. Honaker

Mining Engineering Faculty Publications

Recovery of rare earth elements (REEs) from coal samples collected from the Fire Clay coal seam using diluted mineral acid solutions was investigated. The initial processing step was coal recovery using conventional froth flotation which concentrated the REEs in tailing material resulting in an upgrade to values around 700 ppm on a dry whole mass basis. Leaching experiments were performed on the flotation tailings material using a 1.2 M sulfuric acid solution adjusted to a temperature of 75 °C to study the extractability of REEs from coal material. The effect of particle size, leaching time, leaching temperature, and solid concentration …

Model Predictive Control And Estimation Of Managed Pressure Drilling Using A Real-Time High Fidelity Flow Model, Junho Park, Cameron Price, David Pixton, Manuel Aghito, Roar Nybø, Knut Bjørkevoll, John Hedengren

Faculty Publications

When drilling an oil or gas well, well pressures may be controlled using a technology called managed pressure drilling. This technology often relies on model predictive control schemes; however, practical limitations have generally led to the use of simplified controller models that do not optimally handle certain perturbations in the physical system. The present work reports on the first implementation of a highly accurate system model that has been adapted for real-time use in a controller. This real-time high-fidelity model approximates the results of offline high-fidelity models without requiring operation by model experts. The effectiveness of the model is demonstrated …

Evaluating Driving Performance Of A Novel Behavior Planning Model On Connected Autonomous Vehicles, Keyur Shah

Honors Scholar Theses

Many current algorithms and approaches in autonomous driving attempt to solve the "trajectory generation" or "trajectory following” problems: given a target behavior (e.g. stay in the current lane at the speed limit or change lane), what trajectory should the vehicle follow, and what inputs should the driving agent apply to the throttle and brake to achieve this trajectory? In this work, we instead focus on the “behavior planning” problem—specifically, should an autonomous vehicle change lane or keep lane given the current state of the system?

In addition, current theory mainly focuses on single-vehicle systems, where vehicles do not communicate with …

3-D Printed Hybrid Propulsion Solutions For Smallsat Lunar Landing And Sample Return, Stephen A. Whitmore

Funded Research Records

No abstract provided.

Aps March Meeting 2020: Undergraduate-Friendly Research In Soft Matter And Beyond, Vianney Gimenez-Pinto

Title III Professional Development Reports

The in-person APS March Meeting 2020 taking place in Denver during March 02-06, 2020 was canceled in the last minute out of Covid-19 concerns for the well-being of the scientific community as well as the population of the city of Denver and the state of Colorado. Nevertheless, well-planned logistics by the physics community and the APS leadership, allowed attendants to share their findings, presenting their research works to their peers, and continuing the work towards the advancement of science. Given the historical and on-going under-representation of students of color in science and technology at all academic levels, there is a …

Understanding Air Pollutants And Meteorology Interactions Using Chemical Transport Models, Pengfei Wang

LSU Doctoral Dissertations

Air pollution is a worldwide threat to human health and ecosystems, especially in developing countries. After being emitted to the atmosphere, air pollutant concentrations are determined by chemical and physical processes including transport, transformation, and deposition, which are largely affected by meteorological variations. In turn, pollutants such as fine particulate matter (PM_2.5) affect meteorology by impacting solar radiation and cloud condensation processes. Thus, it is important and necessary to understand the interactions between air pollutants and meteorology for better designing effective air pollution control strategies and forecasting weather. In this study, two chemical transport models (CTMs) are applied …

Implications Of Soil And Canopy Temperature Uncertainty In The Estimation Of Surface Energy Fluxes Using Tseb2t And High-Resolution Imagery In Commercial Vineyards, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Héctor Nieto, Mac Mckee, Lawrence Hipps, Joseph Alfieri, John H. Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Luis Sanchez, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Estimation of surface energy fluxes using thermal remote sensing–based energy balance models (e.g., TSEB2T) involves the use of local micrometeorological input data of air temperature, wind speed, and incoming solar radiation, as well as vegetation cover and accurate land surface temperature (LST). The physically based Two-source Energy Balance with a Dual Temperature (TSEB2T) model separates soil and canopy temperature (Ts and Tc) to estimate surface energy fluxes including Rn, H, LE, and G. The estimation of Ts and Tc components for the TSEB2T model relies on the linear relationship between the composite land surface temperature and a vegetation index, namely …

To What Extent Does The Eddy Covariance Footprint Cutoff Influence The Estimation Of Surface Energy Fluxes Using Two Source Energy Balance Model And High-Resolution Imagery In Commercial Vineyards?, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Héctor Nieto, Mac Mckee, Lawrence Hipps, Joseph Alfieri, John H. Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Louis Sanchez, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Validation of surface energy fluxes from remote sensing sources is performed using instantaneous field measurements obtained from eddy covariance (EC) instrumentation. An eddy covariance measurement is characterized by a footprint function / weighted area function that describes the mathematical relationship between the spatial distribution of surface flux sources and their corresponding magnitude. The orientation and size of each flux footprint / source area depends on the micro-meteorological conditions at the site as measured by the EC towers, including turbulence fluxes, friction velocity (u_star), and wind speed, all of which influence the dimensions and orientation of the footprint. The …

Nonlinear Power Flow Control For Networked Ac/Dc Microgrids, David G. Wilson, Rush D. Robinett Iii, Wayne Weaver, Steven F. Glover

Michigan Tech Patents

A method for designing feedforward and feedback controllers for integration of stochastic sources and loads into a nonlinear networked AC/DC microgrid system is provided. A reduced order model for general networked AC/DC microgrid systems is suitable for HSSPFC control design. A simple feedforward steady state solution is utilized for the feedforward controls block. Feedback control laws are provided for the energy storage systems. A HSSPFC controller design is implemented that incorporates energy storage systems that provides static and dynamic stability conditions for both the DC random stochastic input side and the AC random stochastic load side. Transient performance was investigated …

Increasing Co2 Efficiency Using Advanced Glazing For Cabin, Naveen Dinesh .

Manipal Institute of Technology, Manipal Theses and Dissertations

Global environmental regulations are getting stricter every year and automobile companies are striving hard to get a better hold in market by meeting these stringent norms. Overall reduction in the automotive emissions is not only limited to complex powertrain modules; but can even be achieved with small changes in the aerodynamics of the vehicle. These changes can have a significant impact in the performance and has the potential to reduce the carbon footprint of the vehicle. From a Cab-Body perspective, efficiency of a vehicle can be attained by practicing effective thermal management of cabin, employing lightweight materials, improving aerodynamics, and …

Evolution Of Computational Thinking Contextualized In A Teacher-Student Collaborative Learning Environment., John Arthur Underwood

LSU Doctoral Dissertations

The discussion of Computational Thinking as a pedagogical concept is now essential as it has found itself integrated into the core science disciplines with its inclusion in all of the Next Generation Science Standards (NGSS, 2018). The need for a practical and functional definition for teacher practitioners is a driving point for many recent research endeavors. Across the United States school systems are currently seeking new methods for expanding their students’ ability to analytically think and to employee real-world problem-solving strategies (Hopson, Simms, and Knezek, 2001). The need for STEM trained individuals crosses both the vocational certified and college degreed …

Waiting-Time Paradox In 1922, Naoki Masuda, Takayuki Hiraoka

Northeast Journal of Complex Systems (NEJCS)

We present an English translation and discussion of an essay that a Japanese physicist, Torahiko Terada, wrote in 1922. In the essay, he described the waiting-time paradox, also called the bus paradox, which is a known mathematical phenomenon in queuing theory, stochastic processes, and modern temporal network analysis. He also observed and analyzed data on Tokyo City trams to verify the relevance of the waiting-time paradox to busy passengers in Tokyo at the time. This essay seems to be one of the earliest documentations of the waiting-time paradox in a sufficiently scientific manner.

Reducing Run-Time Adaptation Space Via Analysis Of Possible Utility Bounds, Clay Stevens, Hamid Bagheri

School of Computing: Conference and Workshop Papers

Self-adaptive systems often employ dynamic programming or similar techniques to select optimal adaptations at run-time. These techniques suffer from the “curse of dimensionality", increasing the cost of run-time adaptation decisions. We propose a novel approach that improves upon the state-of-the-art proactive self-adaptation techniques to reduce the number of possible adaptations that need be considered for each run-time adaptation decision. The approach, realized in a tool called Thallium, employs a combination of automated formal modeling techniques to (i) analyze a structural model of the system showing which configurations are reachable from other configurations and (ii) compute the utility that can be …

Engineering Dopant Position In Structure-Controlled Ceo2-Zro2 Catalysts, Behnam Safavinia

LSU Master's Theses

CeO₂-ZrO₂ (CZO) nanoparticles (NPs) have application in many catalytic reactions, such as methane reformation, due to their oxygen cycling ability. Ni doping has been shown to improve the catalytic activity and acts as an active site for the decomposition of methane. In this work, Ni:CZO NPs were synthesized via a two-step co-precipitation/molten salt synthesis to compare Ni distribution, oxygen vacancy concentration, and catalytic activity relative to a reference state-of-the-art catalyst. To better understand the effects of Ni position and dispersion, and oxygen vacancy formation in these materials, the Ni concentration, reaction time, and deposition methods were varied. …

Design Of Versatile Feedback Control System Components For Selective Laser Sintering, Thomas Chessman

University Scholar Projects

Selective laser sintering (SLS) is an additive manufacturing technique that involves using a laser to fuse powdered material together, layer by layer, in order to create a 3-D product. Despite its numerous benefits over traditional methods of manufacturing, including higher efficiency, versatility, and the ability to process many materials, selective laser sintering suffers from its propensity to generate structural errors during operation.

Feedback control has been shown to improve fabrication quality in other laser-based additive manufacturing techniques when implemented properly. Widespread exploration of applying feedback control in SLS might lead to significant performance improvements in this form of manufacturing.

This …

Algorithms For Data Reliability Based On A Cryptographic Distributed Database (Blockchain), Fayzullo M. Nazarov, Akmal R. Akhatov, Farkhod F. Meliyev

Scientific Journal of Samarkand University

The ever-growing information flow in modern society, the diversity of information technologies, the complexity of tasks solved on a computer, have set many tasks for users of these technologies. Currently, due to the numerous data streams, the need to process this data in a short period is also growing. Due to the large number of data streams for their storage and processing in the shortest possible time it is required to create automated systems. This research paper presents algorithms for solving the problem of increasing data flow by forming a distributed database. Based on this, methods for optimizing the storage …

Provenance-Enabled Packet Path Tracing In The Rpl-Based Internet Of Things, Mohammad Abdellatif, Sabah Suhail, Rasheed Hussain, Shashi Raj Pandey, Abid Khan, Choong Seon Hong

Electrical Engineering

The interconnection of resource-constrained and globally accessible things with unreliable Internet make them vulnerable to attacks such as, but not limited to, data forging, false data injection, and packet drop. Such attacks may affect mission-critical applications that rely on sensor data for decision-making processes, hence, necessitates high assurance of trustworthy data. For the data trustworthiness, provenance is considered to be an effective mechanism that tracks both data acquisition and data transmission. However, provenance management for IoT networks is faced with several challenges such as low energy, bandwidth consumption, and efficient storage. In this paper, we propose a bi-fold Provenance-enabled Packed …

Suitability Of Fusing Vehicle Probe Data And Vessel Data To Contextualize The Multimodal Interaction Impacts On Corridor Mobility – A New Orleans Case Study, Kirk Zeringue

LSU New Orleans Theses and Dissertations

Using New Orleans as a case study, this thesis explores the conflation of vehicle probe data with various vessel datasets to characterize the interactions between container vessels and motor vehicles as it relates to interstate congestion in a port city. The case study investigates the impact of container vessel presence/size, fluctuations in container volumes, and container on barge services on roadway congestion. The exploration relies on comparing different conditions using cumulative distribution functions and the Innovative Trend Analysis. The results showed that fusing vehicle and vessel data is achievable and appropriate, but temporal and data completeness issues can effect results. …

Modeling Of Distributary Channels Formed By A Large Sediment Diversion In Broken Marshland, Dylan Blaskey

LSU New Orleans Theses and Dissertations

A 2-D DELFT3D model was developed to address the morphological response of Barataria Bay, the sediment deposition rate in the receiving basin, and the impact on the existing distributary channels within the broken marsh system due to the proposed Mid-Barataria Sediment Diversion. The model had a mesh size sufficient to accurately represent the development of the distributary channels, localized flooding, erosion, and salinity in the basin. The model predicts that the receiving basin will experience extensive erosion during the first year the diversion is open creating three major distributary pathways which flood much of the basin in freshwater. Most locations …

Response Of Large Diameter Offshore Wind Turbine Monopile Foundations To Extreme Event Loading Expected At U.S. Atlantic Coast Wind Energy Areas, Laura Hulliger

LSU New Orleans Theses and Dissertations

Extra-tropical (ETC) and tropical cyclones (TC) pose potential risks to offshore wind farms along the U.S. Atlantic coast, where the offshore wind energy industry is gaining momentum. This research aims to evaluate the stability of large diameter offshore wind turbine monopile foundations under these extreme conditions using the governing industry practice in IEC 61400-3-1. To quantify the risk at U.S. Atlantic coast wind energy areas (WEAs), the ETC and TC impact frequency and intensity are identified using the NHC Historical Hurricane Tracks Archive. Numerical simulations in Plaxis 3D are performed on foundations ranging from 8 to 12 meters in diameter …

Analysis Of Human Affect And Bug Patterns To Improve Software Quality And Security, Md Rakibul Islam

LSU New Orleans Theses and Dissertations

The impact of software is ever increasing as more and more systems are being software operated. Despite the usefulness of software, many instances software failures have been causing tremendous losses in lives and dollars. Software failures take place because of bugs (i.e., faults) in the software systems. These bugs cause the program to malfunction or crash and expose security vulnerabilities exploitable by malicious hackers.

Studies confirm that software defects and vulnerabilities appear in source code largely due to the human mistakes and errors of the developers. Human performance is impacted by the underlying development process and human affects, such as …

Facilitating Mixed Self-Timed Circuits, Alexandra R. Hanson

University Honors Theses

Designers constrain the ordering of computation events in self-timed circuits to ensure the correct behavior of the circuits. Different circuit families utilize different constraints that, when families are combined, may be more difficult to guarantee in combination without inserting delay to postpone necessary events. By analyzing established constraints of different circuit families like Click and GasP, we are able to identify the small changes necessary to either 1) avoid constraints entirely; or 2) decrease the likelihood of necessary delay insertion. Because delay insertion can be tricky for novice designers and because the likelihood of its requirement increases when mixing different …

College Of Engineering News, Georgia Southern University

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

• MechE Top Student Named to All-District Athletics

College Of Engineering News, Georgia Southern University

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

• Undergraduate BSME Student Earns All-District Honors

Application Of Monte Carlo (Mc) Method And Unscented Transformation (Ut) Method Into Trajectory Prediction Of A Dropped Cylinder In Two Dimensions, Yi Li

LSU New Orleans Theses and Dissertations

Monte Carlo (MC) method is one of the commonly used methods to study stochastic statistical problems in the field of marine engineering. There is no doubt that MC’s greatest advantage is its accuracy. However, as a method of using random numbers (or more common pseudo-random numbers) to solve calculation problems, its slow calculation speed is criticized, and its accuracy also depends on the selection of appropriate random times. The equations of the cylindrical motion with three degrees of freedom (surge, heave and pitch) in this article are formulated into a state space model. It is assumed that the small changes …

Evaporation From Undulating Soil Surfaces Under Turbulent Airflow Through Numerical And Experimental Approaches, Bo Gao, John Farnsworth, Kathleen M. Smits

Civil Engineering Faculty Publications - Archive

Evaporation from undulating soil surfaces is rarely studied due to limited modeling theory and inadequate experimental data linking dynamic soil and atmospheric interactions. The goal of this paper is to provide exploratory insights into evaporation behavior from undulating soil surfaces under turbulent conditions through numerical and experimental approaches. A previously developed and verified coupled free flow and porous media flow model was extended by incorporating turbulent airflow through Reynolds-averaged Navier–Stokes equations. The model explicitly describes the relevant physical processes and the key properties in the free flow, porous media, and at the interface, allowing for the analysis of coupled exchange …

Temporal Decomposition For Multi-Interval Optimization In Power Systems, Farnaz Safdarian

LSU Doctoral Dissertations

Large optimization problems are frequently solved for power systems operation and analysis of electricity markets. Many of these problems are multi-interval optimization with intertemporal constraints. The size of optimization problems depends on the size of the system and the length of the considered scheduling horizon. Growing the length of the scheduling horizon increases the computational burden significantly and might make solving the problem in a required time span impossible. Many simplifications and approximation techniques are applied to reduce the computational complexity of multi-interval scheduling problems and make them solvable in a reasonable time span. Geographical decomposition is presented in the …

Experimental Performance Evaluation Of A Hyper-Branched Polymer Electrolyte For Rechargeable Li-Air Batteries, Susanta K. Das, Joel Berry, Abhijit Sarkar

Mechanical Engineering Publications

A hyper-branched polymer (HBP) electrolyte is synthesized for rechargeable lithium-air (Li-air) battery cell and experimentally evaluated its performance in actual battery cell environment. Several real-world battery cells were fabricated with synthesized HBP electrolyte, pure lithium metal as anode and an oxygen permeable air cathode to evaluate reproducibility of the rechargeable Li-air battery cell. The effect of various conditions such as various HBP based electrolytes, discharge current −0.1~0.5 mA, cathode preparation processes and carbon contents on the battery cell performance were experimentally evaluated using the fabricated battery cells under dry air condition. Detailed HBP electrolyte synthesis procedures and experimental performance evaluation …

Brain Structure Changes Over Time In Normal And Mildly Impaired Aged Persons, Charles D. Smith, Linda J. Van Eldik, Gregory A. Jicha, Frederick A. Schmitt, Peter T. Nelson, Erin L. Abner, Richard J. Kryscio, Richard R. Murphy, Anders H. Andersen

Neurology Faculty Publications

Structural brain changes in aging are known to occur even in the absence of dementia, but the magnitudes and regions involved vary between studies. To further characterize these changes, we analyzed paired MRI images acquired with identical protocols and scanner over a median 5.8-year interval. The normal study group comprised 78 elders (25M 53F, baseline age range 70-78 years) who underwent an annual standardized expert assessment of cognition and health and who maintained normal cognition for the duration of the study. We found a longitudinal grey matter (GM) loss rate of 2.56 ± 0.07 ml/year (0.20 ± 0.04%/year) and a …