Digital Commons Network^™

Power Grid Resiliency Enhancement Against Flood-Induced Hazards, Mohadese Movahednia

LSU Doctoral Dissertations

Natural disasters, such as floods, may damage power system assets and lead to widespread and long outages. The impact of flood can be alleviated by preventive actions such as installing tiger dams around power substations before the flood. In this regard, it is imperative that critical substations are identified in terms of the connected load and imposed costs to the system. This study presents a resource allocation approach for protecting power substations against flood events a day ahead of the event. First, the required information for the model is extracted. Flood probability distribution functions are used to generate several flood …

Measuring Motivation, Improving Engagement, H. Colleen Sinclair, Stacey R. Terrio, Youn Kyoung Kim

Reports

To address challenges in the measurement of student motivation to engage with and persist on math tasks, we tackled integrating existing measures and piloting these instruments across two diverse samples to construct 10 reliable scales of pertinent individual differences in math motivation. We present the scales to invite discussion about validity, future use, potential additional motivational measures to consider and applications in schools.

Women At Work: Pathways From Gender Stereotypes To Gender Bias And Discrimination, Madeline E. Heilman, Suzette Caleo, Francesca Manzi

Faculty Publications

Despite important advances, gender-based discrimination continues to hin-der women’s career progress. This review examines the role that gender stereotypes play in promoting gender bias and discrimination. After review- ing what is known about the content of gender stereotypes and examining both their descriptive and prescriptive aspects, we discuss two pathways through which stereotypes result in discrepant work outcomes for women and men. First, we consider how the characterization of women as com- munal but not agentic conflicts with the perceived demands of many male gender-typed jobs and fields, thus promoting perceptions of women’s lack of competence in those areas. Second, …

If You Build It, Will They Come? Assessing Habitat Quality For Marsh Birds At Created Marshes In Southeastern Louisiana, Katherine Aylett Lipford

LSU Master's Theses

Wetland loss occurs at an alarming pace globally, with extremely high rates along the northern Gulf of Mexico. Louisiana loses a football field of wetland every 100 minutes: that is 77,000 m² of wetland bird habitat lost daily. In Louisiana, marsh creation projects combat wetland loss, and while wildlife habitat is often used as a justification for restoration, wildlife receives little to no consideration during and after construction. Habitat characteristics such as site-specific hydrology, vegetation composition, and habitat structure affect the abundance of wetland birds and understanding these features is crucial to creating habitat that will benefit birds. My …

Incubating Education: The Lived Experiences Of Louisiana Elementary And Middle School Teachers When Piloting A 4-H Stem School Enrichment Curriculum, Crystal Rose Ahrens

LSU Doctoral Dissertations

This study addressed a deficiency in the agricultural literacy of the U.S. population by focusing on the challenges that core subject teachers face when integrating agriculture into their curriculum. Using a phenomenological research approach, this investigation explored the lived experiences of Louisiana teachers who piloted a 4-H STEM curriculum, focusing on the growth in agricultural literacy of the teachers while instructing third and eighth-grade students on the agricultural-based and STEM-focused topic of embryology. Employing a transcendental phenomenological approach, I acknowledged my biases through reflexivity and adhered to ethical considerations, including informed consent and confidentiality. Key findings emerged through four themes …

Nonlinear Filtering Of Classical And Quantum Spin Systems, Sivaguru S. Sritharan, Saba Mudaliar

Journal of Stochastic Analysis

No abstract provided.

Machine-Learning-Assisted Leak Detection Using Distributed Temperature And Acoustic Sensors, Hayden Gemeinhardt, Jyotsna Sharma

Faculty Publications

Small leaks, many of which often go undetected using conventional gauges, remain an urgent problem for an aging pipeline infrastructure. This article proposes a method that allows for an automated and robust leak detection and localization system by fusing distributed acoustic sensor (DAS) and distributed temperature sensor (DTS) data for machine learning. Distributed fiber-optic sensing creates an advantage over conventional gauges by providing real-time continuous measurements along the entire length of the fiber-instrumented pipeline at a high spatiotemporal resolution and sensitivity that can detect small leaks, as well as the leak location. High sensitivity, however, can create noisy data. Thus, …

On Lightweight Shape Memory Vitrimer Composites, Siavash Sarrafan, Guoqiang Li

Faculty Publications

Lightweight materials are highly desired in many engineering applications. A popular approach to obtain lightweight polymers is to prepare polymeric syntactic foams by dispersing hollow particles, such as hollow glass microbubbles (HGMs), in a polymer matrix. Integrating shape memory vitrimers (SMVs) in fabricating these syntactic foams enhances their appeal due to the multifunctionality of SMVs. The SMV-based syntactic foams have many potential applications, including actuators, insulators, and sandwich cores. However, there is a knowledge gap in understanding the effect of the HGM volume fraction on different material properties and behaviors. In this study, we prepared an SMV-based syntactic foam to …

Scenario Setup And Forcing Data For Impact Model Evaluation And Impact Attribution Within The Third Round Of The Inter-Sectoral Impact Model Intercomparison Project (Isimip3a), Katja Frieler, Jan Volkholz, Stefan Lange, Jacob Schewe, Matthias Mengel, María Del Rocío Rivas López, Christian Otto, Christopher P.O. Reyer, Dirk Nikolaus Karger, Johanna T. Malle, Simon Treu, Christoph Menz, Julia L. Blanchard, Cheryl S. Harrison, Colleen M. Petrik, Tyler D. Eddy, Kelly Ortega-Cisneros, Camilla Novaglio, Yannick Rousseau, Reg A. Watson, Charles Stock, Xiao Liu, Ryan Heneghan, Derek Tittensor, Olivier Maury, Matthias Büchner, Thomas Vogt, Tingting Wang, Fubao Sun, Inga J. Sauer, Johannes Koch, Inne Vanderkelen, Jonas Jägermeyr

Faculty Publications

This paper describes the rationale and the protocol of the first component of the third simulation round of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3a, http://www.isimip.org, last access: 2 November 2023) and the associated set of climate-related and direct human forcing data (CRF and DHF, respectively). The observation-based climate-related forcings for the first time include high-resolution observational climate forcings derived by orographic downscaling, monthly to hourly coastal water levels, and wind fields associated with historical tropical cyclones. The DHFs include land use patterns, population densities, information about water and agricultural management, and fishing intensities. The ISIMIP3a impact model simulations driven …

Attochemistry Regulation Of Charge Migration, Aderonke Folorunso

LSU Doctoral Dissertations

Charge migration (CM) is a coherent attosecond process that involves the movement of localized holes across a molecule. This phenomenon is potentially useful to understand the fundamental principles of photochemistry, such as light harvesting. The first part of this dissertation discusses the molecular modes of attosecond charge migration. In this work, we used first-principles calculations to investigate the modes of charge migration (CM) in halogenated hydrocarbon chains at attosecond timescales. We have simulated the creation of a localized hole on the halogen atom using constrained density functional theory (DFT) and then tracked its subsequent dynamics with time-dependent DFT (TDDFT). Our …

Research Criteria Towards An Interdisciplinary Stratospheric Aerosol Intervention Assessment, Simone Tilmes, Karen H. Rosenlof, Daniele Visioni, Ewa M. Bednarz, Tyler Felgenhauer, Wake Smith, Chris Lennard, Michael S. Diamond, Matthew Henry, Cheryl S. Harrison, Chelsea Thompson

Faculty Publications

With surface temperatures already reaching unprecedented highs, resulting in significant adverse consequences for societies and ecosystems, there are increasing calls to expand research into climate interventions, including Stratospheric Aerosol Intervention (SAI). However, research and dissemination are currently fragmented and would benefit from a comprehensive international assessment of the current state of knowledge regarding impacts, risks, and recommendations for future SAI research directions. The goals of a scientific assessment would be to describe the current state of SAI research and evaluate proposed scenario-strategy combinations through well-designed evaluation guidelines. The suggested iterative approach would integrate natural and social science considerations to guide …

A Scalogram-Based Cnn Approach For Audio Classification In Construction Sites, Michele Scarpiniti, Raffaele Parisi, Yong Cheol Lee

Faculty Publications

The automatic monitoring of activities in construction sites through the proper use of acoustic signals is a recent field of research that is currently in continuous evolution. In particular, the use of techniques based on Convolutional Neural Networks (CNNs) working on the spectrogram of the signal or its mel-scale variants was demonstrated to be quite successful. Nevertheless, the spectrogram has some limitations, which are due to the intrinsic trade-off between temporal and spectral resolutions. In order to overcome these limitations, in this paper, we propose employing the scalogramas a proper time–frequency representation of the audio signal. The scalogram is defined …

R Tools For Mesoscale Soil Hydrology, Vinit Sehgal

E-Textbooks

The book R Tools for Mesoscale Soil Hydrology is a comprehensive guide designed to equip researchers and practitioners with practical skills in geospatial data analysis using the R programming language. This material is developed to bridge the gap between theoretical soil hydrology and practical geospatial data analysis using open-source tools. As mesoscale soil hydrology increasingly relies on satellite remote sensing and large-scale environmental datasets, the ability to process, analyze, and visualize such data has become essential. This guide introduces a suite of R-based tools and workflows tailored for soil hydrology applications, with a focus on soil moisture, land-atmosphere interactions, and …

Louisiana Agriculture Magazine, Winter 2024, Lsu Agcenter

Louisiana Agriculture

Research at the LSU AgCenter extends well beyond the farm gate. Across 150 acres at the Hammond Research Station, experts in landscape horticulture test the best ways to grow ornamental plants and trees. In Baton Rouge, researchers study how to protect homes in the path of a hurricane. Across the state the AgCenter Healthy Communities team works to empower food pantries and improve sidewalks and other pedestrian infrastructure in rural areas.

This issue of Louisiana Agriculture focuses on these topics along with new research on soil health and high-tech delivery systems for sugarcane ripening agents. Other articles focus on the …

Understanding Inequality In U.S. Farm Subsidies Using Large-Scale Administrative Data, Jisang Yu, Sunghun Lim

Faculty Publications

Using a large-scale, individual-level administrative data set for 2008–2021, we document the inequality in farm program payments across all recipients in the U.S. By examining the relationship between within-county inequality and demographic characteristics of farmers in a county, we find that there is a positive association between the share of Black operators and within-county inequality. We also provide suggestive evidence that a substantial portion of racial and gender disparities in farm payments are associated with crop production characteristics. We then utilize name information in farm payment data to infer the race and gender of individual payees. The analysis using approximately …

The Lavatory Lens: Tracking The Global Movement Of Pathogens Via Aircraft Wastewater, Aaron Bivins, Robert Morfino, Andrew Franklin, Stuart Simpson, Warish Ahmed

Faculty Publications

Modern commercial air travel connects disparate human populations. The global airline industry transported as many as 4.5 billion passengers annually in the years leading up to the COVID-19 pandemic. While such connections are convenient for commerce and tourism, air travel networks can also be efficient distributors of infectious diseases. During the COVID-19 pandemic, public health agencies used multi-layered control strategies to manage the risk of COVID-19 transmission associated with air travel. Simultaneously, the surveillance of aircraft wastewater was further developed as a promising new method to screen for COVID-19, including newly emerging lineages, among international travelers. Herein, we review the …

Identifying Wrong-Way Driving Entry Points On Interstate Highways Using Land-Use Impact Assessment And 911 Calls, Farman Mia, Samer Dessouky

Data

The research aims to provide insight into the initiation event of Wrong-way Driving (WWD) on highways. The intense severity of a WWD accident is encouraging the authorities to install mitigation systems that will ensure safety for motorists on highways. The WWD events are mostly resulting of intoxicated driving, where the unconscious driver takes the wrong way to enter the highway and place other motorists into life-threatening danger. This research attempted to explore from basic knowledge of WWD occurrence to examine the origin and driving philosophy of intoxicated drivers from land-use impact and mathematical modeling point of views. To identify the …

Investigating The Efficacy Of Natural And Nature-Based Features To Increase The Service Life Of Coastal Roadways, Navid Jafari, Mohammad O. Hassan

Publications

Wetlands serve as essential natural barriers, protecting coastal regions against the increasing threats from hurricane-induced storm surges, rising sea levels, and changing weather patterns. Understanding their structural resilience is crucial, particularly the shear strength of the wetland soil-root matrix, which contributes significantly to stability under extreme weather events. However, evaluating this shear strength is challenging due to the complex nature of root systems and the varying amounts of live biomass and necromass at different soil depths. This study utilized a Large-scale Direct Shear Apparatus (LDSA) to address this gap by assessing the shear strength of root biomass in a horizontal …

Impact Report, 2023-2024, Lsu Libraries

Libraries Impact Reports

No abstract provided.

Algebraic And Geometric Properties Of A Family Of Rational Curves, J. William Hoffman, Haohao Wang

Faculty Publications

This paper consists of two components - an application part and a theoretical part, where the former targets the applications of computer aided geometric designs in generating parametric curves, and the latter focuses on the algebraic analysis of rational space curves. At the application level, we construct a family of rational space curves via quaternion products of two generating curves. At the theoretical level, we use algebraic methods to extract a µ-basis for this family of curves, and describe a basis for a special submodule of the syzygy module in terms of a µ-basis for the syzygy module of this …

Matroids Arising From Nested Sequences Of Flats In Projective And Affine Geometries, Matthew Mizell, James Oxley

Faculty Publications

Targets are matroids that arise from a nested sequence of flats in a projective geometry. This class of matroids was introduced by Nelson and Nomoto, who found the forbidden induced restrictions for binary targets. This paper generalizes their result to targets arising from projective geometries over GF (q). We also consider targets arising from nested sequences of affine flats and determine the forbidden induced restrictions for affine targets.

Torsion Invariants Of Complexes Of Groups, Boris Okun, Kevin Schreve

Faculty Publications

Suppose a residually finite group G acts cocompactly on a contractible complex with strict fundamental domain Q, where the stabilizers are either trivial or have normal \BbbZ-subgroups. Let @Q be the subcomplex of Q with nontrivial stabilizers. Our main result is a computation of the homology torsion growth of a chain of finite index normal subgroups of G. We show that independent of the chain, the normalized torsion limits to the torsion of @Q shifted a degree. Under milder assumptions of acyclicity of nontrivial stabilizers, we show similar formulas for the mod p-homology growth. We also obtain formulas for the …

The Imaging X-Ray Polarimetry Explorer 2.5 Years Later, Paolo Soffitta, Luca Baldini, Wayne Baumgartner, Ronaldo Bellazzini, Stephen D. Bongiorno, Niccolò Bucciantini, Enrico Costa, Michal Dovčiak, Steven Ehlert, Philip E. Kaaret, Jeffery J. Kolodziejczak, Luca Latronico, Frédréic Marin, Alan P. Marscher, Herman L. Marshall, Giorgio Matt, Fabio Muleri, Stephen L. O'Dell, Juri Poutanen, Brian Ramsey, Roger W. Romani, Patrick Slane, Allyn F. Tennant, Roberto Turolla, Martin C. Weisskopf, Iván Agudo, Lucio Angelo Antonelli, Matteo Bachetti, Stefano Bianchi, Raffaella Bonino, Alessandro Brez, Fiamma Capitanio, Simone Castellano

Faculty Publications

We have, at last, an observatory dedicated to X-ray polarimetry that has been operational since December 9^th, 2021. The Imaging X-ray Polarimetry Explorer (IXPE) is a NASA SMEX mission, in partnership with ASI, based on three X-ray telescopes, each equipped with a polarization-sensitive detector in the focus. An extending boom was deployed in orbit, positioning the detectors at the optimal distance from the optics, which have a 4-meter focal length. The spacecraft is three-axis stabilized, providing power, attitude determination and control, transmission, and commanding capabilities. After two and a half years of observation, IXPE has detected positive polarization …

A Nonlinear Least-Squares Convexity Enforcing C0 Interior Penalty Method For The Monge–Ampère Equation On Strictly Convex Smooth Planar Domains, Susanne C. Brenner, Li Yeng Sung, Zhiyu Tan, Hongchao Zhang

Faculty Publications

We construct a nonlinear least-squares finite element method for com­puting the smooth convex solutions of the Dirichlet boundary value problem of the Monge-Ampère equation on strictly convex smooth domains in R². It is based on an isoparametric C⁰ finite element space with exotic degrees of freedom that can enforce the convexity of the approximate solutions. A priori and a posteriori error estimates together with corroborating numerical results are presented.

Right-Angled Artin Subgroups Of Right-Angled Coxeter And Artin Groups, Pallavi Dani, Ivan Levcovitz

Faculty Publications

We determine when certain natural classes of subgroups of right-angled Coxeter groups (RACGs) and right-angled Artin groups (RAAGs) are themselves RAAGs. We characterize finite-index visual RAAG subgroups of 2–dimensional RACGs. As an application, we show that any 2–dimensional, one-ended RACG with planar defining graph is quasi-isometric to a RAAG if and only if it is commensurable to a RAAG. Additionally, we give new examples of RACGs with nonplanar defining graphs which are commensurable to RAAGs. Finally, we give a new proof of a result of Dyer: every subgroup generated by conjugates of RAAG generators is itself a RAAG.

Feature Engineering Of Environmental Covariates Improves Plant Genomic-Enabled Prediction, Osval A. Montesinos-López, Leonardo Crespo-Herrera, Carolina Saint Pierre, Bernabe Cano-Paez, Gloria Isabel Huerta-Prado, Brandon Alejandro Mosqueda-González, Sofia Ramos-Pulido, Guillermo Gerard, Khalid Alnowibet, Roberto Fritsche-Neto, Abelardo Montesinos-López, José Crossa

Faculty Publications

Introduction: Because Genomic selection (GS) is a predictive methodology, it needs to guarantee high-prediction accuracies for practical implementations. However, since many factors affect the prediction performance of this methodology, its practical implementation still needs to be improved in many breeding programs. For this reason, many strategies have been explored to improve the prediction performance of this methodology. Methods: When environmental covariates are incorporated as inputs in the genomic prediction models, this information only sometimes helps increase prediction performance. For this reason, this investigation explores the use of feature engineering on the environmental covariates to enhance the prediction performance of genomic …

Teaching Difficult Topics: Reflections From The Undergraduate Music Classroom, Olivia R. Lucas, Laura Moore Pruett

Faculty Publications

Teaching Difficult Topics provides a series of on-the-ground reflections from college music instructors working in a wide variety of institutional settings about their approaches to inclusive, supportive pedagogy in the music classroom. Although some imagine the music classroom to be an apolitical space, instructors find themselves increasingly in need of resources for incorporating issues of race and ethnicity, gender and sexuality, and historical trauma into their classrooms in ways that support student learning and safeguard their classroom communities. The teaching reflections in Teaching Difficult Topics examine difficult themes that fall into three primary categories: subjects that instructors sense to be …

The Role Of Holistic Mentoring Ecosystems In Mitigating Covid-19 Pandemic Impacts On The Persistence Of Low-Income Stem Students, Raeshan D. Davis, Zakiya S. Wilson-Kennedy

Faculty Publications

Holistic mentoring ecosystems are a comprehensive approach to addressing the diverse needs of students through interconnected support networks. While mentoring has been well-documented in existing literature, more research is needed to determine the effectiveness of mentoring ecosystems in mitigating the impact of critical junctures for vulnerable, high-attrition student populations. Guided by Tinto’s model of retention, this qualitative case study investigated the role of holistic mentoring ecosystems in mitigating the impacts of the two combined critical junctures—the COVID-19 pandemic and the first year of college—on low-income STEM undergraduates. Our findings suggest that holistic mentoring ecosystems were essential in helping students adjust …

Upper Bounds For The Lagrangian Cobordism Relation On Legendrian Links, Joshua M. Sabloff, David Shea Vela-Vick, C. M.Michael Wong

Faculty Publications

Lagrangian cobordism induces a preorder on the set of Legendrian links in any contact 3–manifold. We show that any finite collection of null-homologous Legendrian links in a contact 3–manifold with a common rotation number has an upper bound with respect to the preorder. In particular, we construct an exact Lagrangian cobordism from each element of the collection to a common Legendrian link. This construction allows us to define a notion of minimal Lagrangian genus between any two null-homologous Legendrian links with a common rotation number.

Modelling And Simulation Of The Cholesteric Landau-De Gennes Model, Andrew L. Hicks, Shawn W. Walker

Faculty Publications

This paper discusses modelling and numerical issues in the simulation of the Landau-de Gennes (LdG) model of nematic liquid crystals (LCs) with cholesteric effects. We propose a fully implicit, (weighted) L2 gradient flow for computing energy minimizers of the LdG model, and note a time-step restriction for the flow to be energy decreasing. Furthermore, we give a mesh size restriction, for finite-element discretizations, that is critical to avoid spurious numerical artifacts in discrete minimizers, particularly when simulating cholesteric LCs that exhibit 'twist.' Furthermore, we perform a computational exploration of the model and present several numerical simulations in three dimensions, on …