Digital Commons Network^™

A Case Study Of Fourth Grade Students' Literacy Difficulties With Mathematical Word Problems, Rosalind Hudson

LSU Doctoral Dissertations

ABSTRACT

Students have had difficulties with mathematical word problems since they were introduced in their early elementary grades. Elementary teachers have dealt with student difficulties in solving mathematical word problems. In addition, elementary teachers are always implementing and searching for research-based strategies to remediate the deficits in solving mathematical word problems. Year after year across the United States, local education agencies implement math and reading curriculums to support students learning in mathematical word problem solving with reading comprehension, but students are still not able to describe their difficulties when they are given mathematical word problems to solve with all the …

Droplet-Based Fuel Property Measurements, Wanjun Dang

LSU Doctoral Dissertations

Ongoing work to find renewable biofuels to function as drop-in replacements or blending components with gasoline has identified a large number of fuel candidates. Given the vast number of potential biomass-derived fuel molecules and limited sample sizes, screening tools are required to down-select candidate fuels having desired physical properties to ensure good engine performance. This work investigates approaches for rapid screening of candidate fuels using micro-liter sample sizes targeting four properties -- surface tension, viscosity, heat of vaporization (HOV), and vapor pressure. Measurement techniques for fuel properties are developed based on unit phenomena for liquid fuel droplets including droplet oscillation …

Functional Structure Of Biomacromolecules In Plant Biomass Using Solid-State Nmr And Dynamic Nuclear Polarization, Alex Kipchirchir Kirui

LSU Doctoral Dissertations

This dissertation summarizes the recent findings on complex biomacromolecules in cell wall of plants and fungi which perform important roles in cell recognition, structural build up, and energy storage. Because of the technical difficulty in characterizing these biomacromolecules, which are often polymorphic and disordered in structure, the functional structure of these biomacromolecules remains elusive. In this dissertation, I present two solid-state nuclear magnetic resonance (ssNMR) and dynamic nuclear polarization (DNP) studies of carbohydrate-rich biosystems: the energy-rich plant biomass and disease-relevant, pathogenic fungi.

First, we have investigated the secondary cell wall of plant biomass which is a carbohydrate-rich biosystem using solid …

Limits On Parameter Estimation Of Quantum Channels, Vishal Katariya

LSU Doctoral Dissertations

The aim of this thesis is to develop a theoretical framework to study parameter estimation of quantum channels. We begin by describing the classical task of parameter estimation that we build upon. In its most basic form, parameter estimation is the task of obtaining an estimate of an unknown parameter from some experimental data. This experimental data can be seen as a number of samples of a parameterized probability distribution. In general, the goal of such a task is to obtain an estimate of the unknown parameter while minimizing its error.

We study the task of estimating unknown parameters which …

Inductor Free Methods For Breaking Dc Currents, Sudipta Sen

LSU Doctoral Dissertations

The current interruption in dc circuits is more difficult to achieve compared to the ac circuits because, unlike ac systems, dc circuits do not have the natural current zero-crossing. Presently there are three categories of basic dc breaker models namely mechanical, static, and hybrid dc breakers. As current power systems is moving more towards microgrids, DERs, Electric Vehicles (EVs), and with recent advancements in dc circuits, wide verities of dc power sources, and loads, dc breakers are very important in future system protection.

New alternate methods to break dc currents for low-voltage applications are proposed in this work. The proposed …

Surface Engineering Of Materials For Optical And Biomedical Applications, Syed Mohammad Abid Hasan

LSU Doctoral Dissertations

The mechanisms of various optical and medical applications depend on the characteristics of the surface of the material which is being used to detect the molecule of interest. In this work, we focused on some specific areas of surface engineering that play a vital role to improve the performance of some material characteristics. Firstly, we focused on the wettability of graphene, which is important for surface modification and thermal/fluidic properties. The level of transparency to van der Waals forces, chemical bonds, and electrostatic interactions between atoms and molecules on two sides of graphene single layer is not well understood. Our …

Optimal Design Problems With State Constraints, Nha Van Tran

LSU Doctoral Dissertations

This thesis focuses on constrained optimization problems with constraints on the state variables. When the constraints involve partial differential equations or variational inequalities, the optimization problem is also known as Mathematical Programs with Equilibrium Constraints. First, we applied active-set properties of optimal solutions to transform variational inequality constraints into partial differential equation constraints and devised an active-set method which allowed us to solve the optimization problems using the adjoint approach. We extended our approach to evolution problems with constraints on the trajectory of the state variable, such as the irreversibility condition in fracture mechanics. We implemented a gradient descent algorithm …

3-Dimensional Structural Determination Of Epidermal Growth Factor-Like Repeat 27 From Mouse Notch1 Using Nuclear Magnetic Resonance Spectroscopy, Justin Grennell

LSU Doctoral Dissertations

NOTCH1 has been associated with a variety of human ailments, such as cancer and heart disease. NOTCH1 is a transmembrane protein that contains 36 epidermal growth factor-like (EGF) repeats, which facilitate cell signaling by binding proteins on neighboring cells. Each repeat contains about 40 amino acids and has to be folded in a specific manner to function properly. The amino acid sequence, carbohydrate pattern, and calcium-binding sites of EGF-like repeats vary, but the pattern along the 36-repeat chain is conserved. The Abruptex region (EGF24-29) of NOTCH1 is a highly glycosylated (having undergone sugar addition) and flexible region, which gained its …

An Investigation Examining The Closing Of The Achievement Gap In Louisiana With The Ngss, George Cage

LSU Doctoral Dissertations

The purpose of this study was to investigate the Next Generation Science Standards (NGSS) and its implications of being a curricular and pedagogical intervention in terms of narrowing the achievement gap in science education for Children of Color. In using the explanatory mixed methods design, standardized test data and one-on-one interviews were examined to assess the effectiveness and impact of the NGSS’ implementation in the state of Louisiana. This study utilized student performance results from the LEAP 2025 to conduct a statistical analysis that measured trends in performance by Children of Color, specifically Black students, before and after the implementation …

Non-Adiabatic Excited State Molecular Dynamics Using Ehrenfest And Modulated X-Ray Absorption In Titania, Alexander Matthew Meyer

LSU Doctoral Dissertations

This dissertation contains two separate sections aside from an introduction (Chapter 1): theory and methods (Chapter 2), time dependent density functional theory with Ehrenfest for excited state lifetimes in materials (Chapter 3), and simulated field modulated X-ray absorption in titania (Chapter 4).

Excited state lifetime in insulators and semiconductors can be difficult to compute using quantum chemistry due to their dense excited states. Non-radiative decay in these materials requires the use of non-adiabatic effects to dissipate energy through the means of electron-nuclear coupling such as coherent phonon generation. One method of approaching this challenge in these materials is using Ehrenfest …

Numerical Investigation Of The Impact Of Distortion On The Hydrodynamics In The Lower Mississippi River Physical Model (Lmrpm), Ali Heidarizhaleh

LSU Doctoral Dissertations

The Lower Mississippi River Physical Model (LMRPM) is a distorted-scale, 1:6000 horizontal and 1:400 vertical, movable-bed model that is being used to complement ongoing numerical and field studies directed at studying how non-cohesive sediment transport will be impacted by future changes in relative sea level rise and river discharges, as well various management strategies, such as river sediment diversions, in the lower ~190 miles of the Mississippi River The LMRPM was designed using Froude number (Fr) similarity between the prototype and the model, while the flow Reynolds number is relaxed, but determined to be high enough to ensure rough turbulent …

Congruences Between Coefficients Of A Class Of Eta-Quotients And Their Applications To Combinatorics, Shashika Petta Mestrige

LSU Doctoral Dissertations

Ramanujan in $1920$s discovered remarkable congruence properties of the partition function $p(n)$. Later, Watson and Atkin proved these congruences using the theory of modular forms. Atkin, Gordon, and Hughes extended these works to $k$-colored partition functions. In $2010$, Folsom-Kent-Ono and Boylan-Webb proved the congruences of $p(n)$ by studying a $\ell$-adic module associated with a certain sequence of modular functions which are related to $p(n)$.

Primary goal of this thesis is to generalize the work of Atkin, Gordon, Hughes, Folsom-Kent-Ono, and Boylan-Webb about the partition function to a larger class of partition functions. For this purpose we study a closely related …

System Design And Optimization For Efficient Flash-Based Caching In Data Centers, Jian Liu

LSU Doctoral Dissertations

Modern data centers are the backbone of today’s Internet-based services and applications. With the explosive growth of the Internet data and a wider range of data-intensive applications being deployed, it is increasingly challenging for data centers to satisfy the ever-increasing demand for high-quality data services. To relieve the heavy burden on data center systems and accelerate data processing, a popular cost-efficient solution is to deploy high-speed, large-capacity flash-based cache systems. However, we are facing multiple critical challenges from device hardware, systems, to application workloads. In this dissertation, we focus on designing highly efficient caching solutions to cope with the explosive …

Metal Fatigue And Crack Propagation Using Thermodynamic/Thermoelectric Approach, Behnam Hajshirmohammadi

LSU Doctoral Dissertations

The present dissertation concentrates on the fatigue life of metals and fatigue crack growth (FCG). The basic concept of fatigue thermodynamics is used for this purpose. With the application of thermoelectricity, a method is developed on the basis of fracture fatigue entropy (FFE) for the rapid estimation of the fatigue life of components. To this end, thermoelectric signals captured from a specimen during cyclic loading are analyzed, and a procedure is proposed for the calculation of fatigue life based on the thermoelectric signals in the beginning and the steady-state zone of fatigue. Temperature gradient and electric potential gradients in metals …

Interface-Induced Lattice Structure And Magnetism In Ultrathin Transition Metal Oxide Trilayers, David Howe

LSU Doctoral Dissertations

The study of magnetism has been a rich playground in condensed matter physics due to the multiple mechanisms capable of producing the effect and its relationship to multiple characteristics of a material. Transition metal oxides (TMOs) have been of particular interest for ongoing research into magnetic phenomenon due to the abundance of interesting physical phenomena found in member systems such as colossal magnetoresistance, skyrmion formation, and interface-driven 2D electron gases. Thin films introduce an additional thickness-dependent element, where reduction below a critical thickness eliminates the magnetic coherence of a system and FM order is lost. The atomic structure of these …

Pore-Scale Modeling Of Fluid Flow And Particle Transport In Multi-Scale Porous Media, Bin Wang

LSU Doctoral Dissertations

Nanomaterials have recently gained much interest in the field of petroleum engineering and environmental engineering. Understanding the particle transport mechanisms in geological porous media is important to design fit-for-purpose nanomaterials and certain operating parameters for practical usage of those materials. It has been known that natural rock has multi-scale porosity (macroporosity and microporosity) in nature. The microporosity can have a strong impact on the flow and mass transport, but the microscale physics and macroscopic consequences remain poorly understood.

The first part of this dissertation introduces a new higher-order, locally mass conserving FEM method. Stokes equation and Darcy equation are solved …

Fatigue Damage Quantification And Life Estimation With Provision For Microstructure, Arash Pourbagheri Jirandehi

LSU Doctoral Dissertations

This dissertation provides methodologies for the quantification of different forms of fatigue damage by considering the role of microstructure. The laws of thermodynamics in conjunction with Finite Element Method (FEM) are utilized to devise thermodynamically-base frameworks for the estimation of cyclic damage in polycrystalline metals. Accordingly, a microstructure-sensitive platform for fatigue life estimation is introduced. The proposed framework is assessed for 3D printed metallic alloys at room and elevated temperatures. Further, it is used to analyze the fatigue performance difference between additively manufactured Inconel 718 in three print orientations. This research is of fundamental vital interest because it ensures that …

Impact Of Software Changes On User Experience, Job Michael Champagne

LSU Doctoral Dissertations

Software changes are performed frequently to allow cutting edge features to be delivered to users in a timely manner and to assuage the ever increasing security vulnerabilities found in software. These changes, while necessary, can leave users dissatisfied with software that they use. Security patches can slow down computer performance, and extensive user interface changes can leave users dissatisfied. This research presents a methodology for identifying which software changes have high potential to cause user dissatisfaction. As a part of the methodology, we use natural language processing to analyze the software or system requirements business rule text to determine which …

Assessing Mangrove Wetland Structure And Function Regulated By Environmental Gradients Under Climate Change And Increasing Human Impacts: A Modeling Approach, Xiaochen Zhao

LSU Doctoral Dissertations

Mangroves are blue-carbon-rich wetlands that can potentially contribute to climate change mitigation policies. However, mangroves are increasingly impacted by both natural and human disturbances worldwide that require restoration and rehabilitation programs to advance their conservation. Yet, there are major knowledge gaps in our understanding of how local resources (nutrients), regulators (e.g., salinity) and hydroperiod gradients interact in controlling mangrove role as carbon sink or source at different spatiotemporal scales under increasing disturbance frequency and climate change.

Here, I developed a mass-balance-based hydrology model to estimate soil porewater salinity (PWS) in riverine mangroves along the Shark River estuary (SRE), South Florida; …

Floodplain Forests Vegetation Dynamics Driven By Water Deficits Across Scales, Nga Thanh Nguyen

LSU Doctoral Dissertations

Restoration of floodplain ecosystems relies on identifying the most crucial hydrologic process which has been altered by human and climate. Flooding is a well-known dominant hydrologic process for floodplain ecosystems, but surprisingly little is known about drought's role in structuring ecosystems. In addition, several issues remained uncertain, such as the nature of drought within floodplains and the sensitivity of floodplain species-specific growth to climate. These gaps of understanding have in common in missing observations of mechanistic pathways of vegetation response to water deficits at multiple scales in time and space.Generally, this research contributed to floodplain management by expanding our understanding …

Colloidal Nanomaterial Surface Chemistry And Characterization Studied By Linear And Nonlinear Spectroscopy, Asela Sampath Dikkumbura

LSU Doctoral Dissertations

Recent studies have demonstrated the use of nanomaterials such as metallic nanoparticles, liposomes, and polymer microparticles for biomedical applications, encompassing the field of nanomedicine. For developing novel core-shell metallic nanoparticles with controlled surface morphology, the in situ growth dynamics of colloidal silver-gold core-shell (Ag@Au CS) nanoparticles (NPs) in water are monitored in a stepwise synthesis approach using time-dependent second harmonic generation (SHG) and extinction spectroscopy. Transmission electron microscopy images show that the CS NP surface morphology becomes more smooth and uniform as the reaction proceeds, corresponding to lower, stable SHG signals and narrower plasmonic spectra that are compared to finite-difference …

Classifying Soft X-Ray Objects In The Galactic Bulge, Joshua D. Wetuski

LSU Doctoral Dissertations

The Galactic Bulge Survey (GBS) is a broad and shallow X-ray survey designed to detect quiescent X-ray binary systems in the direction of the Milky Way bulge, which include objects such as low-mass X-ray binaries, cataclysmic variables, and symbiotic binaries. LMXBs can provide constraints to the neutron star equation of state and symbiotic systems and are likely progenitors of double white dwarf systems which are themselves candidate progenitors to type Ia supernova. We seek to improve identification and classification of optical counterparts to GBS in several ways. By improving upon the original GBS, an updated catalog was created to help …

The Young Black Girl: A Narration Of Stem Identity Through Science Origin In Elementary School, Heather F. Lavender

LSU Doctoral Dissertations

An ethnographic qualitative case study was conducted by examining the perceptions of two 5^th grade Black girls at an independent school about their involvement with school science, the impact of race and gender towards their perception, and the influence of teachers, peers, and family on their science identity. Black girls are often relegated to outsider status within the classroom, lacking power and authority, which results in Black girls being denied a rightful presence in their learning community (Dumas & Ross, 2016). Additionally, their presence in STEM careers does not reflect their presence nationwide (Graves et al., 2014). The proposed …

Understanding And Overcoming Challenges To Photochemical Water Treatment Technologies, Mostafa Maghsoodi

LSU Doctoral Dissertations

Photochemical water treatment technologies have been extensively studied in recent years to update the current practices and find an innovative, cheap, and sustainable way to treat contaminated water. Despite the well-documented advantages, these technologies faced some challenges and limitations in the way of technology transfer. Among all the challenges, the presence of dissolved organic matter (DOM) poses a serious challenge to the application of these technologies, especially photocatalysis. Moreover, the prospect of utilizing the new technology of light-emitting diodes (LEDs) offers an upgrade in the efficiency of the current practice of ultraviolet (UV) dosing. To understand the effect of DOM …

Rigid Connections On The Projective Line With Elliptic Toral Singularities, Alisina Azhang

LSU Doctoral Dissertations

We generalize two studies of rigid $G$-connections on $\pp$ which have an irregular singularity at origin and a regular singularity at infinity with unipotent monodromy: one is the work of Kamgarpour-Sage which classifies rigid homogeneous Coxeter $G$-connections with slope $\frac{r}{h}$, where $h$ is the Coxeter number of $G$, and the other is the work of Chen, which proves the existence of rigid homogeneous elliptic regular $G$-connections with slope $\frac{1}{m}$, where $m$ is an elliptic number for $G$. In our work, similar to Chen, we look for rigid homogeneous elliptic regular $G$-connections, but we allow the slope to have a numerator …

Electromagnetic Transitions And Beta Decays In Nuclei From The Ab Initio Symmetry-Adapted No-Core Shell Model, Grigor Sargsyan

LSU Doctoral Dissertations

Nuclear physics today is a diverse field, involving research that extends from the minus- cule scales of neutrons and protons to the colossal dimensions of astrophysical objects in the universe. And since the ab initio methods in nuclear physics use realistic internucleon interactions, nuclear modeling has gained predictive capabilities that enable us to probe ever more deeply into the fundamental nature of matter. One of these models – the symmetry- adapted no-core shell model (SA-NCSM) – is capable of reaching the medium-mass region of the chart of the nuclides, by exploiting the emergent symmetries of nuclei, and is therefore well-suited …

The Emergence Of The Legitimacy Of Religious Healing Knowledge In Taiwan, Wei-Cheng Chiu

LSU Doctoral Dissertations

This dissertation investigates how religious healing knowledge has been defined and used by scholars, physicians, and New Agers and how religious healing knowledge emerged as a legitimate area of knowledge in Taiwan. The key position of religious healing knowledge within the entanglement between religion and spirituality is also examined. After the martial law was lifted in 1987, Taiwan’s society had rapidly diversified, and its religions were at the transition point between the old and the new. Meanwhile, the new spirituality culture was introduced into Taiwan in the 1980s and got popular in the 1990s, and it inherited the trend of …

Three Learning Contexts As Paths To Preservice Instrumental Music Teachers' Score Analysis, Rehearsal Planning, And Instructional Readiness: An Exploratory Study In Professional Development, Jennifer Lee Pulling

LSU Doctoral Dissertations

Despite an abundance of evidence-based research pointing to the effectiveness of long-term teacher professional development (PD) (Darling-Hammond, Hyler & Gardner, 2017; Desimone, 2009), instrumental music teachers who seek to improve their teaching practices are limited to and often prefer short-term PD opportunities (Bauer, 2007; West, 2020). In recent years, a growing knowledge base focused on music teacher PD has given attention to long-term, content-based and collaborative music PD (Conway, 2015; Kastner, 2014; Stanley, Snell & Edgar, 2014) while a dearth of evidence-based research exists on short-term music PD (Bauer, 2007; West, 2020). The purpose of this collective case study was …

Using Performance Cues As A Memorization Strategy With Group Piano Students By Implementing Teacher And Student-Directed Learning Approaches, Maria Eduarda Lucena Vieira

LSU Doctoral Dissertations

Multiple researchers have explored the use of performance cues in memorization for music students, suggesting that it is an effective method for memorization (Chaffin & Imreh, 2002; Gerling & Dos Santos, 2017; Hallam et al., 2008). Based on the current literature about the use of memorization strategies, researchers have found a method of a secure, solid, and effective technique called Performance Cues (Chaffin & Imreh, 2002; Hallam et al, 2008). When working with students, the teacher can guide them with steps to understand how the music works and help them to find a secure memorization process where they will feel …

Laser Surface Treatment And Laser Powder Bed Fusion Additive Manufacturing Study Using Custom Designed 3d Printer And The Application Of Machine Learning In Materials Science, Hao Wen

LSU Doctoral Dissertations

Selective Laser Melting (SLM) is a laser powder bed fusion (L-PBF) based additive manufacturing (AM) method, which uses a laser beam to melt the selected areas of the metal powder bed. A customized SLM 3D printer that can handle a small quantity of metal powders was built in the lab to achieve versatile research purposes. The hardware design, electrical diagrams, and software functions are introduced in Chapter 2. Several laser surface engineering and SLM experiments were conducted using this customized machine which showed the functionality of the machine and some prospective fields that this machine can be utilized. Chapter 3 …