Digital Commons Network^™

Correction: Design Of Crack-Free Laser Additive Manufactured Inconel 939 Alloy Driven By Computational Thermodynamics Method (Mrs Communications, (2022), 12, 5, (844-849), 10.1557/S43579-022-00253-X), Congyuan Zeng, Huan Ding, Uttam Bhandari, S. M. Guo

Faculty Publications

The article Design of crack-free laser additive manufactured Inconel 939 alloy driven by computational thermodynamics method, written by Congyuan Zeng, Huan Ding, Uttam Bhandari, S. M. Guo, was originally published electronically on the publisher’s internet portal on 9 September 2022 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 20 December 2022 to © The Author(s) 2022 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate …

Wind Loads On Overhead Sign Structures: A Comparative Study, Aly Mousaad Aly, James Benson

Faculty Publications

Road signs are prone to extreme winds that cause significant damage. Overhead sign structures can disrupt traffic and cause harm to the traveling public if a failure occurs under extreme wind conditions. In this paper, we employ Computational Fluid Dynamics (CFD) in a comparative study to understand the aerodynamics of standard, porous, and curved signs. The study shows the viability of porous and curved overhead boards for lessening aerodynamic loads, which can mini-mize damage and enhance safety on roadways. Porous overhead signs can decrease the drag forces; however, the size of the openings is a vital parameter in reducing wind …

Vibration Attenuation In A High-Rise Hybrid-Timber Building: A Comparative Study, Suvash Chapain, Aly Mousaad Aly

Faculty Publications

Recent developments in engineered timber products, and their availability, durability, and renewability, have led to taller and more flexible buildings. However, these buildings may experience excessive vibrations, resulting in safety and serviceability issues due to wind or earthquake loads. This paper presents a dynamic analysis of a 42-story-tall hybrid-timber building, along with a comparative study of the performance of three damping devices: (i) pendulum pounding tuned mass damper (PTMD), (ii) tuned mass damper inerter (TMDI), and (iii) tuned mass damper (TMD). First, we evaluate the vibration reduction capability of the TMD and the TMDI under filtered white noise and variable …

A Simple Micromilled Microfluidic Impedance Cytometer With Vertical Parallel Electrodes For Cell Viability Analysis, Jason Eades, Julianne F. Audiffred, Micah Fincher, Jin Woo Choi, Steven A. Soper, William Todd Monroe

Faculty Publications

Microfluidic impedance cytometry has been demonstrated as an effective platform for single cell analysis, taking advantage of microfabricated features and dielectric cell sensing methods. In this study, we present a simple microfluidic device to improve the sensitivity, accuracy, and throughput of single suspension cell viability analysis using vertical sidewall electrodes fabricated by a widely accessible negative manufacturing method. A microchannel milled through a 75 µm platinum wire, which was embedded into poly-methyl-methacrylate (PMMA), created a pair of parallel vertical sidewall platinum electrodes. Jurkat cells were interrogated in a custom low-conductivity buffer (1.2 ± 0.04 mS/cm) to reduce current leakage and …

Non-Equilibrium Colloidal Phenomena In Magnetic Fields And Photoillumination: From Controlling Living Microbots To Understanding Microplastics, Ahmed Al Harraq

LSU Doctoral Dissertations

Colloids are a ubiquitous class of materials composed of microscopic particles suspended in a continuous phase which are found in everyday products and in nature. Colloids are also useful models for studying the spontaneous arrangement of matter from individual building blocks to mesophases. Standard treatment of colloid science is based on the assumption of equilibrium conditions, as defined in traditional thermodynamics. However, novel assembly mechanisms and motility are unlocked by pushing colloids away from equilibrium using external energy. In addition, many colloids in nature and in industrial applications exchange energy and mass with the surrounding environment thus behaving in a …

Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran

LSU Doctoral Dissertations

This dissertation explores the mechanisms driving sediment transport and deposition on the continental shelf and within the bays of the northern Gulf of Mexico via a suite of geophysical methods and sediment cores on a variety of timescales. This dissertation is comprised of three main chapters, each focusing on a different location, environment, and process but tied together using geophysical survey, a thematic focus on geomorphic change and sediment transport within the deltaic cycle and deltaic plain environments, and the implications this change poses for both past and future sediment transport and environmental change in response to sea level change. …

Publisher Correction: A Very Luminous Jet From The Disruption Of A Star By A Massive Black Hole (Nature, (2022), 612, 7940, (430-434), 10.1038/S41586-022-05465-8), Igor Andreoni, Michael W. Coughlin, Daniel A. Perley, Yuhan Yao, Wenbin Lu, S. Bradley Cenko, Harsh Kumar, Shreya Anand, Anna Y.Q. Ho, Mansi M. Kasliwal, Antonio De Ugarte Postigo, Ana Sagués-Carracedo, Steve Schulze, D. Alexander Kann, S. R. Kulkarni, Jesper Sollerman, Nial Tanvir, Armin Rest, Luca Izzo, Jean J. Somalwar, David L. Kaplan, Tomás Ahumada, G. C. Anupama, Katie Auchettl, Sudhanshu Barway, Eric C. Bellm, Varun Bhalerao, Joshua S. Bloom, Michael Bremer, Mattia Bulla, Eric Burns, Sergio Campana, Poonam Chandra

Faculty Publications

In the version of this article initially published, there was in an error in the third-to-last sentence of the abstract, now reading, in part, “we calculate a rate of 0.02–0.01 +0.04 Gpc–3 yr–1”, where Gpc was spelled out as gigapascals, not gigaparsecs. Also, the scale label (2″) was missing in the lower-left corner of Fig. 1b. The errors have been corrected in the HTML and PDF versions of the article.

An Exploration Of Black Women Faculty Members' Faculty Development And Career Advancement Experiences Within A Pwi, Monica N. Guient

LSU Doctoral Dissertations

At a large, research-intensive, predominantly White university, in this qualitative case study, Black women faculty members’ experiences with and perceptions of institutionally sponsored faculty development activities in relation to career advancement was explored. The career advancement of faculty members from underrepresented and minoritized populations—particularly Black women—is ultimately impacted by the racialized and gendered disparities among tenure-track and tenured professors in research, service, and teaching. Unique to this study is the exploration of how Black women faculty members experience the human resource development practice of faculty development while also gathering information from the institutional leaders who oversee and guide institutionally sponsored …

Integrated Ion-Exchange Membrane Resin Wafer Assemblies For Aromatic Organic Acid Separations Using Electrodeionization, Matthew L. Jordan, Grzegorz Kokoszka, Hishara Keshani Gallage Dona, Dodangodage Ishara Senadheera, Revati Kumar, Yupo J. Lin, Christopher G. Arges

Faculty Publications

Aromatic acids, such as p-coumaric acid, are valuable chemical intermediates that are used in the specialty chemical industries because they are precursors to phenylpropanoid compounds. The separation of p-coumaric acid from fermentation broths is a critical step in the biochemical production process and more broadly the circular carbon economy. Electrodeionization (EDI) has been applied toward separations of low-carbon chain acids, but purifying p-coumaric acid has been challenging due to fouling and irreversible binding with ion-exchange membranes and resins. Here, we report a new membrane wafer assembly (MWA) consisting of laminated ion exchange membranes to porous ionomer-binder resin wafers for EDI. …

First-Principles Molecular Dynamics Study Of Liquid Iron-Rich Alloys Under Conditions Of The Earth’S Core, Dipendra Banjara

LSU Doctoral Dissertations

In this dissertation, we report the results of the first-principles molecular dynamics (FPMD) simulations and data analysis on the thermodynamic, structural, and transport properties of iron-rich metallic liquids considering several light and heavy elements under wide ranges of pressure and temperature that are relevant to the earth’s core. Our simulations of pure liquid iron cover the pressure range from 0 GPa at 2000 K to 380 GPa at 7000 K perhaps representing the most extensive computational study to date. We studied four molten iron-rich alloys corresponding to 2.67 atom% of Ni, Co, Mo, and W at pressures up to 380 …

Controls Of Physical Drivers On The Formation And Toxicity Of Harmful Cyanobacteria Blooms (Cyanohabs), Courtney N. Hammond

LSU Master's Theses

Estuaries within the Gulf of Mexico are exhibiting profound alterations due to climatic changes and the implementation of coastal restoration activities. These changes are attributed to the increasing frequency of harmful cyanobacteria blooms (cyanoHABs) within Lake Pontchartrain, an estuary located in southeastern Louisiana, USA. There is a better understanding into how the opening of the Bonnet Carré Spillway (BCS) impacts cyanoHAB formations compared to the effect of other physical drivers when the spillway doesn’t dominate the system. The goal of this study is to provide a greater understanding of the baseline conditions when the BCS is closed and determine what …

Development Of A Peptide-Based Protac Incorporating A Β-Hairpin Sequence, Hannah Catherine Hymel

LSU Doctoral Dissertations

The ubiquitin-proteasome system (UPS) is a biochemical pathway primarily responsible for the degradation of damaged proteins. The UPS is regulated by E3 ubiquitin ligases, which recognize specific degradation sequences, or degrons, on a protein leading to protein ubiquitination and subsequent degradation by the proteasome. Proteolysis targeting chimeras (PROTACs) have emerged as a novel therapeutic agent to selectively degrade ‘undruggable’ targets; however, many peptide-based PROTACs suffer low cell permeability and high protease susceptibility. The goal of this work is to utilize degron-based substrates that function as cell penetrating peptides (CPPs) in a PROTAC to selectively degrade a target. The first part …

Editorial: Abiotic Stress: Molecular Genetics And Genomics, Volume Ii, Rohini Garg, Prasanta K. Subudhi, Rajeev K. Varshney, Mukesh Jain

Faculty Publications

No abstract provided.

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 …

Data-Driven Nonparametric Joint Chance-Constrained Programming For Power Systems Scheduling, Chutian Wu

LSU Doctoral Dissertations

This dissertation is dedicated to implementing data-driven nonparametric joint chance constraints (JCC) to power system optimization problems. Power generated by renewable sources, such as solar farms, is an uncertain parameter. Several approaches solve optimization under uncertainty, including stochastic programming, robust programming, and chance-constrained programming. Uncertain parameters may not belong to any parametric class of probability functions. Thus, methods that consider such uncertainty as a random variable that fits in a known probability density function (PDF) have limitations. This study focuses on chance-constrained programming under nonparametric or data-driven distributionally robust uncertainty settings.

Studies based on chance-constrained programming usually focus on individual …

Introduction To Control Engineering, Xiangyu Meng

E-Textbooks

This is an introductory level textbook for control engineering.

Finding Forensic Evidence In The Operating System's Graphical User Interface, Edward X. Wilson Mr.

LSU Master's Theses

A branch of cyber security known as memory forensics focuses on extracting meaningful evidence from system memory. This analysis is often referred to as volatile memory analysis, and is generally performed on memory captures acquired from target systems. Inside of a memory capture is the complete state of a system under investigation, including the contents of currently running as well as previously executed applications. Analysis of this data can reveal a significant amount of activity that occurred on a system since the last reboot. For this research, the Windows operating system is targeted. In particular, the graphical user interface component …

Visual Analytics And Modeling Of Materials Property Data, Diwas Bhattarai

LSU Doctoral Dissertations

Due to significant advancements in experimental and computational techniques, materials data are abundant. To facilitate data-driven research, it calls for a system for managing and sharing data and supporting a set of tools for effective data analysis and modeling. Generally, a given material property M can be considered as a multivariate data problem. The dimensions of M are the values of the property itself, the conditions (pressure P, temperature T, and multi-component composition X) that control the concerned property, and relevant metadata I (source, date).

Here we present a comprehensive database considering both experimental and computational sources …

Media Literacy In Public Education: A Mixed-Method Exploration, Jessica Wyers

LSU Doctoral Dissertations

You have to know where you are to know where you’re going. This is the approach I attempt to take to understand next steps in media literacy education and policy. Little research has been done to understand the current state of media literacy education, what is actually happening in the classrooms and education system, to better judge more intentional interventions in the future.

This dissertation explores the current issues in media literacy education in our public schools. I combine the strengths of a qualitative investigation of published public school media literacy curricula with survey data measuring the perceptions of students’ …

Ion Transport On Self-Assembled Block Copolymer Electrolytes With Different Side Chain Chemistries, Mario V. Ramos-Garcés, Dodangodage Ishara Senadheera, Karthik Arunagiri, Polyxeni P. Angelopoulou, Georgios Sakellariou, Ke Li, Bryan D. Vogt, Revati Kumar, Christopher G. Arges

Faculty Publications

Ion-exchange membranes (IEMs) are used in electrochemical systems for a wide variety of applications, including water purification, mineral recovery, and energy storage and conversion. These materials often dictate the ohmic overpotential drop in electrochemical systems and can have a profound impact on process efficiency. Central to the rationale design of ion-conducting polymers is a fundamental understanding as to how chemical composition and macromolecular architecture influence ion and water transport. Herein, we report the preparation of three microphase separated block copolymer electrolytes (BCEs) with long-range order that have different side chain chemistries in the ionic domain. The side chain variants are …

Computational Study Of C-C Coupling Reactions On Heterogeneous Catalysts, Md Saeedur Rahman

LSU Doctoral Dissertations

The utilization of carbon dioxide (CO₂) in chemical production has attracted global research interest. Reacting CO₂ with methane (CH₄) removes these greenhouse gases from the atmosphere and turns both compounds into building blocks for organic compound synthesis. A commonly explored pathway involves dry reforming of methane (DRM), which reacts CH₄ and CO₂ to form syngas, a mixture of H₂ and CO. Syngas is a widely used feedstock for synthesizing chemicals ranging from methanol to fuels via the Fischer-Tropsch (FT) process. However, DRM has a large positive ΔGº, which requires the …

Sexual Dimorphism In Corallite Size And Modularity Of A Broadcast Spawning Coral, Porites Lobata, Ricardo M. Pedraza-Pohlenz, Eduardo F. Balart, J. J.Adolfo Tortolero-Langarica, Alma Paola Rodríguez-Troncoso, Michael E. Hellberg, Orión Norzagaray-López, Rafael A. Cabral-Tena, Amílcar Leví Cupul-Magaña, David A. Paz-García

Faculty Publications

Differences in selective pressures and the energetic cost of gametes in gonochoristic corals should vary with the sex of the colony, which may lead to sexual dimorphism. Coral colonies are composed of subunits (corallites) that create a complex morphological architecture. If corallite features are distinct between sexes, then the degree of coordinated change among these subunits may also vary (phenotypic modularity). This study tested for sexual dimorphism in the corallites of the reef-building coral Porites lobata, a gonochoric broadcast spawner, and compared this with previously demonstrated sexual dimorphism in its congener P. panamensis, a gonochoric brooder. Corallite area in P. …

Changing Features Of The Northern Hemisphere 500-Hpa Circumpolar Vortex, Nazla Bushra, Robert V. Rohli, Chunyan Li, Paul W. Miller, Rubayet Bin Mostafiz

Faculty Publications

The tropospheric circumpolar vortex (CPV), an important signature of processes steering the general atmospheric circulation, surrounds each pole and is linked to the surface weather conditions. The CPV can be characterized by its area and circularity ratio (Rc), which both vary temporally. This research advances previous work identifying the daily 500-hPa Northern Hemispheric CPV (NHCPV) area, Rc, and temporal trends in its centroid by examining linear trends and periodic cycles in NHCPV area and Rc (1979–2017). Results suggest that NHCPV area has increased linearly over time. However, a more representative signal of the planetary warming may be the temporally weakening …

Flood Risk Assessment For Residences At The Neighborhood Scale By Owner/Occupant Type And First-Floor Height, Ayat Al Assi, Rubayet Bin Mostafiz, Carol J. Friedland, Md Adilur Rahim, Robert V. Rohli

Faculty Publications

Evaluating flood risk is an essential component of understanding and increasing community resilience. A robust approach for quantifying flood risk in terms of average annual loss (AAL) in dollars across multiple homes is needed to provide valuable information for stakeholder decision-making. This research develops a computational framework to evaluate AAL at the neighborhood level by owner/occupant type (i.e., homeowner, landlord, and tenant) for increasing first-floor height (FFH). The AAL values were calculated here by numerically integrating loss-exceedance probability distributions to represent economic annual flood risk to the building, contents, and use. A simple case study for a census block in …

Expanding Swirl Combustor Operability On Methane-Ammonia-Air Mixtures Using A Distributed Fuel Injection Technique And Inlet Air Preheating, V. Viswamithra, M. Gurunadhan, S. Menon

Faculty Publications

The necessity to reduce greenhouse gas emissions has prompted the search for carbon-free fuel alternatives. One such carbon-free fuel source that can be used for power generation in a gas turbine-based system is ammonia. Ammonia combustion poses challenges due to reduced flame speed and reactivity, which can be alleviated by addition of methane or natural gas. However, NOx emissions continue to be an issue, which needs resolution before practical consideration of ammonia as a fuel source. One of the potential solutions that has been proposed is a two-stage, rich-lean combustion process to minimize NOx while ensuring complete reactant consumption. This …

Skinks Of Oceania, New Guinea, And Eastern Wallacea: An Underexplored Biodiversity Hotspot, Alex Slavenko, Allen Allison, Christopher C. Austin, Aaron M. Bauer, Rafe M. Brown, Robert N. Fisher, Ivan Ineich, Bulisa Iova, Benjamin R. Karin, Fred Kraus, Sven Mecke, Shai Meiri, Clare Morrison, Paul M. Oliver, Mark O. Shea, Jonathan Q. Richmond, Glenn M. Shea, Oliver J.S. Tallowin, David G. Chapple

Faculty Publications

Context. Skinks comprise the dominant component of the terrestrial vertebrate fauna in Oceania, New Guinea, and Eastern Wallacea (ONGEW). However, knowledge of their diversity is incomplete, and their conservation needs are poorly understood. Aims. To explore the diversity and threat status of the skinks of ONGEW and identify knowledge gaps and conservation needs. Methods. We compiled a list of all skink species occurring in the region and their threat categories designated by the International Union for Conservation of Nature. We used available genetic sequences deposited in the National Center for Biotechnology Information's GenBank to generate a phylogeny of the region’s …

Multilayered Graphene And Methods Of Making The Same, Manas Ranjan Gartia, Ardalan Chaichi

College of Engineering Patents

The present invention relates in part to a method of fabricating graphene structures from graphene oxide by reducing the graphene oxide on a patterned substrate. The invention also relates in part to graphene structures produced using said method and electrodes and capacitors comprising said graphene structures.

Drivers Of Diatom Production And The Legacy Of Eutrophication In Two River Plume Regions Of The Northern Gulf Of Mexico, Jeffrey W. Krause, Adam D. Boyette, Israel A. Marquez, Rebecca A. Pickering, Kanchan Maiti

Faculty Publications

In the northern Gulf of Mexico (nGoM), the Louisiana Shelf (LS) and Mississippi Bight (MB) subregions are influenced by eutrophication to varying degrees. Despite recognition that dissolved silicon may regulate diatom productivity in the nGoM, there is only one published data set reporting biogenic silica (bSiO2) production rates for each subregion. We report that bSiO2 production rates on the LS and MB are high and appear to be controlled by different nutrients among seasons. Despite exceptional upper trophic level biomass regionally, which suggests significant primary production by diatoms (as in other systems), gross euphotic-zone integrated bSiO2 production rates are lower …

Dissolved Organic Carbon Dynamics And Fluxes In Mississippi-Atchafalaya Deltaic System Impacted By An Extreme Flood Event And Hurricanes: A Multi-Satellite Approach Using Sentinel-2/3 And Landsat-8/9 Data, Bingqing Liu, Eurico J. D’Sa, Francesca Messina, Melissa M. Baustian, Kanchan Maiti, Victor H. Rivera-Monroy, Wei Huang, Ioannis Y. Georgiou

Faculty Publications

Transport of riverine and wetland-derived dissolved organic carbon (DOC) spanning tidal wetlands, estuaries, and continental shelf waters functionally connects terrestrial and aquatic carbon reservoirs, yet the magnitude and ecological significance of this variable and its spatiotemporal linkage remains uncertain for coastal deltaic regions, such as Mississippi River Delta Plain, which includes Mississippi (MR) and Atchafalaya (AR) rivers and estuaries with vast expanses of wetlands and coastal forests. We examined DOC dynamics and fluxes in this large river-dominated wetland-estuarine system for the period between 2019 and 2021 that included an extreme river flood event in 2019, two major hurricanes (Barry in …

Global Sea Surface Cyclogeostrophic Currents Derived From Satellite Altimetry Data, Yuhan Cao, Changming Dong, Alexandre Stegner, Brandon J. Bethel, Chunyan Li, Jihai Dong, L. Haibin, Jingsong Yang

Faculty Publications

Sea surface currents (SSC) derived from the sea surface height anomalies (SSHA) as measured by multi-satellite altimeters are widely used for various applications including studies on ocean dynamics, marine ecology, and climate change. However, present SSC products estimated on the assumption of an idealized geostrophic balance is biased. To overcome this idealization, this study considers flow curvature in the estimation of sea surface velocities in the global ocean, with the computation scheme validated using numerical model results. It is demonstrated that the inclusion of curvature into SSC estimations significantly changes SSC dynamic features in terms of kinetic energy, enstrophy (the …