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Rebar-Free 3d Printing Of Transportation Infrastructure, Ali Kazemian, Marwa Hassan, Hassan Noorvand, Gabriel Arce, Hassan Ahmed, Ilerioluwa Giwa

Publications

This study investigates the fresh and hardened-state properties of printing mixtures including different dosages of steel fibers, especially at higher dosages which have not been investigated before. This study also considers the effects of other parameters such as sand-to-powder ratio and the limestone content on the properties of steel fiber reinforced printing materials, to reduce the Portland cement content which has a high carbon footprint. The obtained experimental results revealed that high-performance materials incorporating up to 2.5% steel fibers (by volume) can be successfully 3D printed. The mechanical properties of the reinforced mixtures improved significantly at high fiber dosages (2% …

Resilient 3d-Printed Civil Infrastructure With Ultra-High Performance Engineered Cementitious Composites (Uhpeccs), Hassan Noorvand, Marwa Hassan, Ali Kazemian, Gabriel Andres Arce Amador, Daniel E. Game

Publications

This study aims to develop and evaluate UHP-ECC materials for 3DP applications. To achieve this, the rheological properties of the cementitious composites were designed to accommodate 3DP functionality. Additionally, this study aimed to evaluate the hardened properties of the 3D-printed UHP-ECCs and compare them to the cast UHP-ECCs. Furthermore, the effect of variables such as sand-to-binder (S/B), fly ash-to-cement ratio (FA/C), and high-range water reducer (HRWR) content on the fresh and hardened properties of the 3D printable mixtures were evaluated. Fresh properties of mixtures were assessed by means of the flowability test, setting time test, and printability test. Hardened properties …

Resilient 3d-Printed Civil Infrastructure With Ultra-High Performance Engineered Cementitious Composites (Uhpeccs), Hassan Noorvand, Marwa Hassan, Ali Kazemian, Gabriel Andres Arce Amador, Daniel E. Game

Data

This study aims to develop and evaluate UHP-ECC materials for 3DP applications. To achieve this, the rheological properties of the cementitious composites were designed to accommodate 3DP functionality. Additionally, this study aimed to evaluate the hardened properties of the 3D-printed UHP-ECCs and compare them to the cast UHP-ECCs. Furthermore, the effect of variables such as sand-to-binder (S/B), fly ash-to-cement ratio (FA/C), and high-range water reducer (HRWR) content on the fresh and hardened properties of the 3D printable mixtures were evaluated. Fresh properties of mixtures were assessed by means of the flowability test, setting time test, and printability test. Hardened properties …

Hydrologic Connectivity And Residence Time Affect The Sediment Trapping Efficiency And Dissolved Oxygen Concentrations Of The Atchafalaya River Basin, Daniel E. Kroes, Richard H. Day, Michael D. Kaller, Charles R. Demas, William E. Kelso, Tiffany Pasco, Raynie Harlan, Steven Roberts

Faculty Publications

Little is known about water movement, volume, or residence time (RT), and how those characteristics affect sediment trapping efficiency (TE) and dissolved oxygen concentrations (DO) in the United States' largest remaining bottomland hardwood swamp, the Atchafalaya River Basin. To better understand these dynamics, this study used bathymetry, lidar, and stage records to determine volumes in the Basin's hydrologically distinct water management units (WMUs). Discharge measurements determined flow distribution and RT. Residence time was compared with DO to identify conditions that coincided with DO increases or decreases. Suspended sediment concentrations (SSC) were used to determine TE relative to calculated and measured …

Louisiana Black-Bellied Whistling-Duck Clutch Characteristics In The Presence Of Conspecific And Interspecific Brood Parasitism, Dylan L. Bakner, Katie E. Miranda, Kevin M. Ringelman

Faculty Publications

Black-bellied Whistling-Ducks (Dendrocygna autumnalis; Whistling-Duck) are undergoing a rapid range expansion northward and now breed throughout the Southeastern United States. As a facultative cavity-nesting species, they have the potential to compete with Wood Ducks (Aix sponsa) and Hooded Mergansers (Lophodytes cucullatus) for nest sites. Little is known about Whistling-Duck breeding biology, and estimates of clutch characteristics and rates of conspecific and interspecific brood parasitism (CBP and IBP, respectively) are lacking. We monitored Whistling-Duck nests in Louisiana to describe nesting chronology, clutch size of parasitized and unparasitized (normal) nests, and hatchability (i.e., the portion of eggs that hatched) for clutches of …

Modeling The Sorption Of Ni(Ii) And Zn(Ii) By Mn Oxide–Coated Sand: Equilibrium And Kinetic Approaches, Joshua T. Padilla, H. Magdi Selim, Lewis A. Gaston

Faculty Publications

The behavior of metal cations in oxide-dominated systems is controlled by sorption reactions, which in turn depend on pH. Descriptions of such reactions are of interest for contaminant monitoring or remediation efforts; however, widely used isotherms such as Freundlich or Langmuir neglect the effect of pH and are therefore limited in their applicability. Two pH-dependent isotherms and their kinetic analogs were developed and evaluated regarding their ability to describe equilibrium and time-dependent sorption of Ni and Zn by Mn oxide–coated sand (MOCS). The sorption of Ni and Zn by MOCS at pH 4.0, 5.5, and 7.0 was investigated using batch …

A Bibliometric Analysis Of Machine Learning Econometrics In Asset Pricing, Hector O. Zapata, Supratik Mukhopadhyay

Faculty Publications

Machine learning (ML) is a novel method that has applications in asset pricing and that fits well within the problem of measurement in economics. Unlike econometrics, ML models are not designed for parameter estimation and inference, but similar to econometrics, they address, and may be better suited for, problems of prediction. While some ML methods have been applied in econometrics for decades, their success in prediction has been limited, and examples of this abound in the asset pricing literature. In recent years, the ML literature has advanced new, more efficient, computation methods for regularization, modeling nonlinearity, and improved out-of-sample prediction. …

Damage Assessment, Michael M. Khonsari, Lijesh Koottaparambil

College of Engineering Patents

Methods of estimating tribological damage described herein include examples where varying power is applied between surfaces engaged in frictional contact. Calculations evaluate power consumed at the relevant frictional contact and temperature values may be gathered to supplement the calculated power. Instantaneous and cumulative assessments of damage are calculated based on that information. Measurements or calculations of electrical power may be used as part of the damage assessment.

Phase Contrast X-Ray Interferometry, Joyoni Dey, Narayan Bhusal, Leslie Butler, Jonathan P. Dowling, Kyungmin Ham, Varshni Singh

College of Science Patents

A phase contrast X-ray imaging system includes: an illumination source adapted to illuminate a region of interest; a diffraction grating adapted to receive illumination from the illuminated region of interest, the diffraction grating comprising a spatial structure having a first periodicity superimposed with a second periodicity that is different from the first periodicity; and a detector adapted to detect illumination passing through the diffraction grating, wherein the spatial structure is defined by varying height and/or pitch, and wherein the spatial structure imparts a first phase dependence based on the first periodicity and an additional phase dependence based on the second …

The Uneven Reaction To Combat The Covid-19 Pandemic: Geovisualizing Of Fever Clinics In Mainland China, Guoqi Li, Zhuoshi Lv, Fahui Wang, Gang Chen, Wenjie Sun, Yuting Shi, Sijing Liu

Faculty Publications

The COVID-19 pandemic has exerted unprecedented impacts on the world. Since its onset, China has established a network of fever clinics as an effective strategy to aggressively isolate and screen possible patients with COVID-19 symptoms. This study presents two fever clinic maps that visualize the uneven responses to the COVID-19 pandemic at the city level in mainland China. The maps highlight more resources in the southwest, northwest, east, and south China, and paucity in the far west parts of southwest and northwest China and in the north and northeast China.

Snapshots Of Coastal Ecology During Glacial And Deglacial Intervals: A Multiproxy Assessment Of Northern Gulf Of Mexico Sediment Cores, Kendall Emilie Brome

LSU Master's Theses

Terrestrial ecosystems along exposed continental shelves during times of relatively low sea level and glaciation are rarely preserved due to the mechanically erosive nature of marine transgression and regression. In this study, I investigate the geochemical and palynological characteristics of two well-preserved sites in the northern Gulf of Mexico (NGOM) to determine the ecologic settings and subsequent mechanisms of preservation in this region. Both sites contain preserved terrigenous sediments of previously exposed coastal margins; the first is located at the Alabama Underwater Forest (~13 km south of Gulf Shores, AL, at ~15 mbsl), and optically stimulated luminescence dates to 72–56 …

Damage Monitoring Methods For Fiber-Reinforced Polymer Joints: A Review, Wencai Li, Genevieve Palardy

Faculty Publications

As the application of composite materials in structural parts continues to increase, so does the importance to monitor the structure's health condition during their entire service life. This paper presents a comprehensive review on damage monitoring methods focusing on fiber-reinforced polymer joints: adhesively bonded, mechanically fastened, and welded. In this review, structural health monitoring (SHM) methods are classified into two major groups: intrinsic sensing (embedded at the bond line) and extrinsic sensing (placed outside the interface). Main intrinsic techniques include fiber optic sensors, piezoelectric sensors (e.g., electromechanical impedance), and nanocomposite-based monitoring. The latter has attracted significant interest in the past …

Subpredictor Approach For Event-Triggered Control Of Discrete-Time Systems With Input Delays, Frédéric Mazenc, Michael Malisoff, Corina Barbalata, Zhong Ping Jiang

Faculty Publications

We propose a new output event-triggered control design for linear discrete-time systems with constant arbitrarily long input delays, using delay compensating subpredictors. We prove input-to-state stability of the closed loop system, using framers and the theory of positive systems. A novel feature of our approach is our use of matrices of absolute values, instead of Euclidean norms, in our discrete-time event triggers for our delay compensating control design. We illustrate our approach using a model of the BlueROV2 marine vehicle, where our new event triggers lead to a smaller number of control recomputation times as compared with standard event triggers …

A Machine Learning Approach For Detecting Rescue Requests From Social Media, Zheye Wang, Nina S.N. Lam, Mingxuan Sun, Xiao Huang, Jin Shang, Lei Zou, Yue Wu, Volodymyr V. Mihunov

Faculty Publications

Hurricane Harvey in 2017 marked an important transition where many disaster victims used social media rather than the overloaded 911 system to seek rescue. This article presents a machine-learning-based detector of rescue requests from Harvey-related Twitter messages, which differentiates itself from existing ones by accounting for the potential impacts of ZIP codes on both the preparation of training samples and the performance of different machine learning models. We investigate how the outcomes of our ZIP code filtering differ from those of a recent, comparable study in terms of generating training data for machine learning models. Following this, experiments are conducted …

Low-Cost Sustainable Engineered Geopolymer Composites (Egcs) For Repair And New Construction Of Transportation Infrastructure, Hassan Noorvand, Marwa Hassan, Miladin Radovic, Svetlana Sukhishvili, Gabriel Arce, Ruwa Abufarsakh, Adriana A. Alvarado, Oscar Huang, Sang Zhen

Publications

This study evaluated the use of cost-effective alternative materials in the formulation of novel low-cost Engineered Geopolymer Composite (EGC) materials for repair and new construction of transportation infrastructure in Region 6. Previous studies and reports have shown that EGCs have excellent mechanical properties, which makes them an eco-friendly and more sustainable alternative to Engineered Cementitious Composites (ECCs). However, the mass adoption of these emerging composites is expected to be hindered by their cost, which is mainly driven by the use of PVA reinforcing fibers, silica fume (SF), and manufactured microsilica sand (MS). To address this key shortcoming, novel low-cost EGC …

Development Of Robotics & Automation Roadmap For Road Construction/Maintenance Projects, Ashrant Aryal, Chao Wang, Chintan Vijay Vora, Sueed A. Willoughby

Publications

Over the past few decades, there have been no significant improvements in the construction industry's productivity. Outside the construction industry, robots have proven to be beneficial in improving productivity, safety, and quality. There is a growing interest in adopting robots in the construction industry to address these issues. As robots get introduced to the project sites, human-robot interaction becomes an important consideration for wide-scale adoption. The success of deploying robots in the construction industry depends on how well humans collaborate with the robots. This project focused on investigating the perception of various construction industry stakeholders in adopting robots in their …

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 …

Polymer Mimetics For Soil Modeling And Detection Of Biomarkers, Md Ragib Hasan

LSU Doctoral Dissertations

The population of the world is increasing day by day and is expected to reach 9.8 billion by the year 2050. The ever-increasing demand for agricultural products is putting an unprecedented strain on the world's soils as the human population continues to expand. Soil degradation caused by over-farming and the agrochemicals (fertilizers, pesticides, etc.) used in agriculture is a growing problem, although its causes remain murky. In addition, little is understood about the molecular-level interactions of substances that are subsequently introduced to soils, such as agricultural chemicals (ACs). Therefore, it is expected that these constraints may be circumvented by the …

Shaky Ground: Educators At The Intersection Of Gender Diversity And Early Childhood Environments, Elizabeth Gragg Elizardi

LSU Doctoral Dissertations

This dissertation examines the hidden curriculum of gender socialization in early childhood classrooms. Purposes of this study included exploring how teachers’ beliefs about gender are enacted in activities, roles, and relationships with children to inform and recommend future directions for gender conscious education and pedagogies. This dissertation includes an assessment of participants’ gender schema, an analysis of participant interviews and focus groups, field notes from classroom observations and artifact collection. This study draws on Brofenbrenner’s (2005) bioecological theory of human development, positioning teachers as a primary engine of development in a child’s life. Cognitive-developmental theories are forwarded to explain gender …

Uvite, Camg 3 (Al5mg)(Si6o18)(Bo3)3(Oh)3(Oh), A New, But Long-Anticipated Mineral Species Of The Tourmaline Supergroup From San Piero In Campo, Elba Island, Italy, Ferdinando Bosi, Cristian Biagioni, Federico Pezzotta, Henrik Skogby, Ulf Hålenius, Jan Cempírek, Frank C. Hawthorne, Aaron J. Lussier, Yassir A. Abdu, Maxwell C. Day, Mostafa Fayek, Christine M. Clark, Joel D. Grice, Darrell J. Henry

Faculty Publications

Uvite, CaMg3(Al5Mg)(Si6O18)(BO3)3(OH)3(OH), is a new mineral of the tourmaline supergroup. It occurs in the Facciatoia quarry, San Piero in Campo, Elba Island, Italy (42°45′04.55″N, 10°12′50.89″E) at the centre of a narrow (2-3 cm wide) vein composed of aggregates of dark brown to black tourmaline, penetrating (magnesite + dolomite)-rich hydrothermally altered metaserpentinite. Crystals are euhedral and up to 1 cm in size, brown with a vitreous lustre, conchoidal fracture and grey streak. Uvite has a Mohs hardness of 7½, a calculated density of 3.115 g/cm3 and is uniaxial (-). Uvite has trigonal symmetry, space group R3m, a = 15.9519(10) Å, c …

Investigating The Relational Element Of Trust In Teacher-Principal Relationships: An Autoethnographic Case Study, Angela Bradley

LSU Doctoral Dissertations

This autoethnographic case study was designed to investigate the relational aspect of trust, a characteristic of servant leadership, in the teacher-principal relationship. This trusting bond is an often overlooked, foundational element of a school’s success. I examined the role that trust plays in enhancing a school’s culture and how trust is established and maintained among one principal and teachers under my supervision. In addition, as researcher, I sought to uncover specific indicators that trust was present on a school campus. Finally, I sought to examine trust’s effects on collaboration and organizational commitment.

Through weekly reflections, I sought to examine my …

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. …

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 …

Thermal Stability And Protective Properties Of Phenylphosphonic Acid On Cu(111), Viacheslav Kalinovych, Md Saeedur Rahman, Lesia Piliai, Yuliia Kosto, Sascha L. Mehl, Tomáš Skála, Iva Matolínová, Vladimír Matolín, Kevin C. Prince, Ye Xu, Nataliya Tsud

Faculty Publications

Phenylphosphonic acid (PPA) adsorbed on Cu(111) has been studied by synchrotron radiation-based techniques in combination with density functional theory calculations. The dehydrogenated phenylphosphonic acid molecule (PP) strongly bound in a tridentate geometry through oxygen atoms to Cu(111) is shown to be the dominant surface species in the temperature range 150–300 °C. The stable PP adlayer substantially protects the Cu(111) surface from oxidation during exposure to ambient conditions. Thermal treatment of the PPA adlayer at 375 °C initiates molecular decomposition through several channels: P–O bond scission forming C6H5PO2; C–P bond scission forming phenyl and PO3; and C–H bond scission forming C6H4PO3. …

Physical To Cyber: A Case Study Of The Print And Digital Literacy Of Burgeoning Older Adult Learners, Laura Elizabeth Williams

LSU Doctoral Dissertations

This intrinsic single case study explored the ways in which two older adult burgeoning literacy learners in a capital city in the U.S. Gulf South utilized the skills of print literacy and digital literacy both together and apart. This study was an investigation of print and digital literacy, individually and combined, in order to examine the way older adult burgeoning literacy learners used one kind of literacy (print) to develop the other (digital). Using semi-structured interviews, observations, and literacy journals, participants’ perceptions were explored. Findings included that fully literate older adults used their literacy to enact and maintain social connections, …

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 …

Utilization Of A Gravity Model To Determine The Impact Of Covid-19 In Us Bilateral Trade, Dacia Lopez Lopez

LSU Master's Theses

In April 2022, the United States traded with approximately 233 countries. Exports and imports of goods and services represent 11.73% and 14.58% of U.S. GDP respectively. Because of that, U.S. bilateral trade is important. COVID-19 impacted the economy and trade in different ways as supply and demand changes. The objective of this study is to determine the impact of COVID-19 in U.S. bilateral trade using an augmented gravity model and panel data from 20 U.S. partner countries and the United States over 24 quarters, from 2015 to 2021.

To accomplish these objectives, a gravity model was used and Random effects …

Influence Of Hesperidin On The Physico-Chemical, Microbiological, And Sensory Characteristics Of Frozen Yogurt, Roberto Antonio Cedillos Hernández

LSU Master's Theses

Frozen yogurts contain yogurt culture bacteria which might impart health benefits to its consumers. Global frozen yogurt market sales are expected to grow 4.8% by 2028 which represents an important opportunity for the industry, consumers, and researchers. Polyphenols are metabolites found in plants which have antioxidant and anti-inflammatory properties and might prevent chronical diseases such as cancer, diabetes, and cardiovascular diseases. The objective of this study was to elucidate the effect of the polyphenol hesperidin on the physico-chemical, microbiological, and sensory characteristics of frozen yogurts. Hesperidin was incorporated in frozen yogurt at three concentrations (500, 250 and 125 mg/90g of …

The Degree Gini Index Of Several Classes Of Random Trees And Their Poissonized Counterparts—Evidence For Duality, Carly Domicolo, Panpan Zhang, Hosam Mahmoud

Journal of Stochastic Analysis

No abstract provided.

Experience That Works: An Investigation Uncovering Essential Elements Of Field Experiences And Internships Within Principal Preparation Programs That Significantly Impact And Contribute To Principal Effectiveness, Nathan Wayne Hite

LSU Doctoral Dissertations

This study applied situational leadership and transformational leadership theories to discern essential elements of principal preparation program field experiences and internships that contributed most to principal effectiveness. Identifying critical components of principal preparation field experiences and internships were imperative to ensure principal effectiveness within the ever-changing landscape of education. The objective of this study was to discover essential components of field experiences and internships provided by principal preparation programs that contributed most to principal effectiveness, increasing the likelihood public school districts hired principal candidates who were equipped with the skills necessary to step into the position with minimal on-the-job training. …