Digital Commons Network^™

Tuning Martensitic Transitions In (Mnnisi)0.65(Fe2ge)0.35 Through Heat Treatment And Hydrostatic Pressure, Jing Han Chen, Ahmad Us Saleheen, Sunil K. Karna, David P. Young, Igor Dubenko, Naushad Ali, Shane Stadler

Faculty Publications

A first-order magneto-structural transition from a ferromagnetic orthorhombic TiNiSi-type martensite phase to a paramagnetic hexagonal Ni 2In-type austenite phase was observed in (MnNiSi) 0.65(Fe 2Ge) 0.35. In this work, we demonstrate that the first-order magneto-structural transition temperature for a given composition is tunable over a wide temperature range through heat treatment and hydrostatic pressure. The first-order transition temperature was reduced by over 100 K as the annealing temperature went from 600 to 900 °C, and this first-order transition was converted to second order when the sample was annealed at 1000 °C. The maximum magnetic-induced isothermal entropy change with μ0ΔH=7 T …

High-Throughput Assessment Of A Novel, Thiol-Acrylate Hydrogel For Tumor Spheroid Synthesis In A Microfluidic Device, Nathan Daniel Kersker

LSU Master's Theses

The extracellular environment plays an important role in regulating cell behavior. The mechanical, structural, and compositional properties of the extracellular matrix can determine the fate of the growing cells. Standard two-dimensional culturing in a flask fails to represent a native cellular environment. To create the native environment suitable for cells, hydrogels were previously studied. One of the most extensively studied synthetic hydrogels was a poly(ethylene glycol diacrylate) (PEGDA) hydrogel. However, the need for UV polymerization may introduce unwanted changes in cell morphology and viability. The hydrogel being proposed was a form of a thiol-acrylate hydrogel that can eliminate this problem …

Local Density Of The Bose-Glass Phase, K. Hettiarachchilage, C. Moore, V. G. Rousseau, K. M. Tam, M. Jarrell, J. Moreno

Faculty Publications

We study the local density of the Bose-Hubbard model in the presence of on-site disorder near the Bose-glass transition using multifractal, typical medium, and percolation theories. At incommensurate filling our findings support the scenario of percolating superfluid clusters enhancing Anderson localization. Scaling analysis of the superfluid density at the incommensurate filling of ρ=1.1 and on-site interaction U=80t predicts a superfluid-Bose-glass transition at disorder strength of Δc≈30t. At this filling the local-density distribution becomes more skew with increasing disorder strength. Multifractal analysis suggests a multifractal behavior resembling that of the Anderson localization. In the Bose-glass phase the mode of the local-density …

Systematic Quantum Cluster Typical Medium Method For The Study Of Localization In Strongly Disordered Electronic Systems, Hanna Terletska, Yi Zhang, Ka Ming Tam, Tom Berlijn, Liviu Chioncel, N. S. Vidhyadhiraja, Mark Jarrell

Faculty Publications

Great progress has been made in recent years towards understanding the properties of disordered electronic systems. In part, this is made possible by recent advances in quantum effective medium methods which enable the study of disorder and electron-electronic interactions on equal footing. They include dynamical mean-field theory and the Coherent Potential Approximation, and their cluster extension, the dynamical cluster approximation. Despite their successes, these methods do not enable the first-principles study of the strongly disordered regime, including the effects of electronic localization. The main focus of this review is the recently developed typical medium dynamical cluster approximation for disordered electronic …

Significant Excess Of Electronlike Events In The Miniboone Short-Baseline Neutrino Experiment, A. A. Aguilar-Arevalo, B. C. Brown, L. Bugel, G. Cheng, J. M. Conrad, R. L. Cooper, R. Dharmapalan, A. Diaz, Z. Djurcic, D. A. Finley, R. Ford, F. G. Garcia, G. T. Garvey, J. Grange, E. C. Huang, W. Huelsnitz, C. Ignarra, R. A. Johnson, G. Karagiorgi, T. Katori, T. Kobilarcik, W. C. Louis, C. Mariani, W. Marsh, G. B. Mills, J. Mirabal, J. Monroe, C. D. Moore, J. Mousseau, P. Nienaber, J. Nowak, B. Osmanov, Z. Pavlovic

Faculty Publications

The MiniBooNE experiment at Fermilab reports results from an analysis of νe appearance data from 12.84×1020 protons on target in neutrino mode, an increase of approximately a factor of 2 over previously reported results. A νe charged-current quasielastic event excess of 381.2±85.2 events (4.5σ) is observed in the energy range 200

Microbial Processes In The Weathering Crust Aquifer Of A Temperate Glacier, Brent C. Christner, Heather F. Lavender, Christina L. Davis, Erin E. Oliver, Sarah U. Neuhaus, Krista F. Myers, Birgit Hagedorn, Slawek M. Tulaczyk, Peter T. Doran, William C. Stone

Faculty Publications

© 2018 Author(s). Incident solar radiation absorbed within the ablation zone of glaciers generates a shallow perched aquifer and seasonal icebound microbial habitat. During the melt seasons of 2014 and 2015, borehole investigations were used to examine the physical, geochemical, and microbiological properties in the near-surface ice and aquifer of the temperate Matanuska Glacier (south-central Alaska). Based on temperature, solar forcing, and ice optical properties, the dissipation of shortwave radiation promoted internal melting and the formation of a weathering crust with a maximum depth of ∼2 m. Boreholes into the weathering crust provided access to water percolating through the porous …

Sexually-Relevant Visual And Chemosensory Signals Induce Distinct Behaviors And Neural Activation Patterns In The Social African Cichlid, Astatotilapia Burtoni, Karen E. Field, Christopher T. Mcvicker, Karen P. Maruska

Faculty Publications

© 2018 Field, McVicker and Maruska. Across vertebrates, the use of multimodal (multiple sensory modalities) signals has evolved to convey important information to receivers. Information content of multimodal signals can be the same as or different from information in each unimodal signal, and are classified as redundant or non-redundant, respectively, based on receivers’ behavioral responses. Despite the prevalence and importance of multimodal signaling across taxa, relatively little is known about how and where these signals are processed in the brains of receivers. We used the social African cichlid fish, Astatotilapia burtoni, to investigate how sexually-relevant visual and chemosensory uni- and …

Compressive Characterization Of Telecom Photon Pairs In The Spatial And Spectral Degrees Of Freedom, Nicola Montaut, Omar S. Magaña-Loaiza, Tim J. Bartley, Varun B. Verma, Sae Woo Nam, Richard P. Mirin, Christine Silberhorn, Thomas Gerrits

Faculty Publications

In the past few years, physicists and engineers have demonstrated the possibility of utilizing multiple degrees of freedom of the photon to perform information processing tasks for a wide variety of applications. Furthermore, complex states of light offer the possibility of encoding and processing many bits of information in a single photon. However, the challenges involved in the process of extracting large amounts of information, encoded in photonic states, impose practical limitations to realistic quantum technologies. Here, we demonstrate characterization of quantum correlated photon pairs in the spatial and spectral degrees of freedom. Our technique utilizes a series of random …

Large-Scale Cosmic-Ray Anisotropies Above 4 Eev Measured By The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, I. F.M. Albuquerque, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, G. A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, H. Asorey, P. Assis, G. Avila, A. M. Badescu, A. Balaceanu, F. Barbato, R. J.Barreira Luz, S. Baur, K. H. Becker, J. A. Bellido, C. Berat, M. E. Bertaina, X. Bertou, P. L. Biermann, J. Biteau, S. G. Blaess, A. Blanco, J. Blazek, C. Bleve

Faculty Publications

We present a detailed study of the large-scale anisotropies of cosmic rays with energies above 4 EeV measured using the Pierre Auger Observatory. For the energy bins [4, 8] EeV and E ≥ 8 EeV, the most significant signal is a dipolar modulation in R.A. at energies above 8 EeV, as previously reported. In this paper we further scrutinize the highest-energy bin by splitting it into three energy ranges. We find that the amplitude of the dipole increases with energy above 4 EeV. The growth can be fitted with a power law with index β = 0.79 ± 0.19. The …

Mindfulness And Teen Behavior: Teenagers' Perceptions Of Behavior That Led To Expulsion, Michelle L. Lee

LSU Master's Theses

The purpose of this study was to examine the effects of teaching specific mindfulness techniques to teens who have difficulty functioning in the classroom, using the Mindful Schools Curricula; the course includes 18 lessons on being mindful of sound, breath, movement, thoughts, and emotions. Specifically, the study was designed to determine whether a mindfulness course would be beneficial for South Parish High School teens who are expelled. The study design was mixed methods. Participants were administered pre- and post- scientific validated survey scales that measure mindfulness characteristics as one data source. Participants’ parents were given a questionnaire to return and …

Enantioselective Functionalization Of Enamides At The Β-Carbon Center With Indoles, Mirza A. Saputra, Binod Nepal, Nitin S. Dange, Pu Du, Frank R. Fronczek, Revati Kumar, Rendy Kartika

Faculty Publications

© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim We report an enantioconvergent approach for the functionalization of enamides at the β-carbon atom, which involves a chiral Brønsted acid induced tautomerization of 2-amidoallyl into 1-amidoallyl cations. These putative reactive intermediates were produced by ionization of racemic α-hydroxy enamides with a chiral Brønsted acid and captured with substituted indoles in a highly regio- and enantioselective manner.

A Comparison Of Machine Learning Techniques For Taxonomic Classification Of Teeth From The Family Bovidae, Gregory J. Matthews, Juliet K. Brophy, Maxwell Luetkemeier, Hongie Gu, George K. Thiruvathukal

Faculty Publications

This study explores the performance of machine learning algorithms on the classification of fossil teeth in the Family Bovidae. Isolated bovid teeth are typically the most common fossils found in southern Africa and they often constitute the basis for paleoenvironmental reconstructions. Taxonomic identification of fossil bovid teeth, however, is often imprecise and subjective. Using modern teeth with known taxons, machine learning algorithms can be trained to classify fossils. Previous work by Brophy et al. [Quantitative morphological analysis of bovid teeth and implications for paleoenvironmental reconstruction of plovers lake, Gauteng Province, South Africa, J. Archaeol. Sci. 41 (2014), pp. 376–388] uses …

Neonatal Vitamin A Injection Promotes Cattle Muscle Growth And Increases Oxidative Muscle Fibers, Bo Wang, Wei Nie, Xing Fu, Jeanene M. De Avila, Yannan Ma, Mei Jun Zhu, Martin Maquivar, Steven M. Parish, Jan R. Busboom, Mark L. Nelson, Min Du

Faculty Publications

© 2018 The Author(s). Background: Vitamin A and its metabolite, retinoic acid (RA), are important regulators of cell differentiation and organ morphogenesis. Its impact on beef cattle muscle growth remains undefined. Method: Angus steer calves were administrated with 0 (control) or 150,000IU vitamin A (retinyl palmitate in glycerol, i.m.) per calf at birth and 1 month of age. At 2 months of age, a biopsy of the Biceps femoris muscle was obtained to analyze the immediate effects of vitamin A injection on myogenic capacity of muscle cells. The resulting steers were harvested at 14months of age. Results: Vitamin A administration …

Recovery Of Phosphate And Dissolved Organic Matter From Aqueous Solution Using A Novel Cao-Mgo Hybrid Carbon Composite And Its Feasibility In Phosphorus Recycling, Ronghua Li, Jim J. Wang, Zengqiang Zhang, Mukesh Kumar Awasthi, Dan Du, Pengfei Dang, Qian Huang, Yichen Zhang, Lu Wang

Faculty Publications

Metal oxide-Carbon composites have been developed tailoring towards specific functionalities for removing pollutants from contaminated environmental systems. In this study, we synthesized a novel CaO-MgO hybrid carbon composite for removal of phosphate and humate by co-pyrolysis of dolomite and sawdust at various temperatures. Increasing of pyrolysis temperature to 900 °C generated a composite rich in carbon, CaO and MgO particles. Phosphate and humate can be removed efficiently by the synthesized composite with the initial solution in the range of pH 3.0–11.0. The phosphate adsorption was best fitted by pseudo-second-order kinetic model, while the humate adsorption followed the pseudo-second-order and the …

The Urban Archaeological Supersite Paradigm: Integrating Archaeology And Hgis Into Heritage Management, Andrea P. White

LSU Doctoral Dissertations

The archaeological heritages of many of the world’s historic cities are at risk. If these urban archaeological resources are destroyed before excavation and documentation using sound archaeological techniques, the material histories of these cities are erased. The Urban Archaeological Supersite Paradigm is presented as means to address some of the threats facing urban archaeological sites.

The urban archaeological supersite paradigm is both an applied and a scholarly research framework useful for examining and interpreting the urban past and for helping to address urban archaeological heritage at risk. It conceptualizes the historic city as a supersite made up of numerous archaeological …

Β -Decay Half-Lives Of Sb 134,134m And Their Isomeric Yield Ratio Produced By The Spontaneous Fission Of Cf 252, K. Siegl, K. Kolos, N. D. Scielzo, A. Aprahamian, G. Savard, M. T. Burkey, M. P. Carpenter, P. Chowdhury, J. A. Clark, P. Copp, G. J. Lane, C. J. Lister, S. T. Marley, E. A. Mccutchan, A. J. Mitchell, J. Rohrer, M. L. Smith, S. Zhu

Faculty Publications

A number of fission products possess isomeric states which have a nuclear spin significantly different from that of the ground state. The yield ratio of these states following fission is influenced by the angular momentum present in the fissioning system. The Sb134m,134 yield ratio had not been previously measured in the spontaneous fission of Cf252; however, it had previously been observed to favor the (7-) isomer over the (0-) ground state in U235(nth,f) and Th232(25 MeV p,f). Using a mass-separated beam of low-energy Sb134,134m ions produced by Cf252 spontaneous fission at the CARIBU facility, β particles and γ rays were …

Rats Fed Dietary Bioactive Components (Resistant Starch, Whole Grains, And Fat) Undergo Altered Biometrics And Gene Expression As A Result Of Gut Fermentation, Justin Lamont Guice

LSU Doctoral Dissertations

The whole grain and fat content of the diet have been previously shown to affect intestinal fermentation and phenotype conferred by high–amylose maize resistant starch (HAMRS), a form of fermentable dietary fiber. The current studies were designed to compare rodent gut health following consumption of whole grain and non–whole grain prebiotics on moderate fat (MF) and high fat (HF) diets, and to optimize health effect based on dosage of whole grain resistant starch prebiotics.

Study 1: Diets were prepared to contain the following factors RS (Present/Absent), WG (Present/Absent), and Fat (HF/MF). A three–way ANOVA was performed with statistical slice …

Neoglacial Climate Anomalies And The Harappan Metamorphosis, Liviu Giosan, William D. Orsi, Marco Coolen, Cornelia Wuchter, Ann G. Dunlea, Kaustubh Thirumalai, Samuel E. Munoz, Peter D. Clift, Jeffrey P. Donnelly, Valier Galy, Dorian Q. Fuller

Faculty Publications

© 2018 Author(s). Climate exerted constraints on the growth and decline of past human societies but our knowledge of temporal and spatial climatic patterns is often too restricted to address causal connections. At a global scale, the inter-hemispheric thermal balance provides an emergent framework for understanding regional Holocene climate variability. As the thermal balance adjusted to gradual changes in the seasonality of insolation, the Intertropical Convergence Zone migrated southward accompanied by a weakening of the Indian summer monsoon. Superimposed on this trend, anomalies such as the Little Ice Age point to asymmetric changes in the extratropics of either hemisphere. Here …

Clustering And Alpha-Capture Reaction Rates From First-Principle Structure Calculations For Nucleosynthesis, A. C. Dreyfuss, K. D. Launey, J. E. Escher, R. B. Baker, J. P. Draayer, T. Dytrych

Faculty Publications

We outline a new formalism that begins with first-principles structure calculations to describe alpha-clustering, and ultimately leads to a description of alpha-capture reaction rates and impacts on abundance patterns from x-ray burst (XRB) nucle-osynthesis. We utilize a symmetry-adapted basis, which allows us to extend traditional ab initio calculations into the larger model spaces needed for the development of collectivity and clustering in nuclei. In particular, the use of symplectic symmetry allows us to describe spatially expansive states in nuclei - including the Hoyle state of 12C, its 2+ excitation, and B(E2) transitions - with only one or a few basis …

Electromagnetic Excitations And Responses In Nuclei From First Principles, R. B. Baker, K. D. Launey, N. Nevo Dinur, S. Bacca, J. P. Draayer, T. Dytrych

Faculty Publications

We discuss the role of clustering on monopole, dipole, and quadrupole excitations in nuclei in the framework of the ab initio symmetry-adapted no-core shell model (SA-NCSM). The SA-NCSM starts from nucleon-nucleon potentials and, by exploring symmetries known to dominate the nuclear dynamics, can reach nuclei up through the calcium region by accommodating ultra-large model spaces critical to descriptions of clustering and collectivity. The results are based on calculations of electromagnetic sum rules and discretized responses using the Lanczos algorithm, that can be used to determine response functions, and for 4He are benchmarked against exact solutions of the hyperspherical harmonics method. …

Emergent Clustering Phenomena In The Framework Of The Ab Initio Symmetry-Adapted No-Core Shell Model, K. D. Launey, A. Mercenne, G. H. Sargsyan, H. Shows, R. B. Baker, M. E. Miora, T. Dytrych, J. P. Draayer

Faculty Publications

This article discusses the emergence - from first principles - of collectivity and clustering in light and intermediate-mass nuclei, up to the calcium region, with implications for reproducing enhanced E2 transitions in deformed nuclei, and for further understanding the formation of alpha clustering. Structure calculations use nucleon-nucleon chiral potentials and are based on the ab initio symmetry-adapted no-core shell model (SA-NCSM) that expands the reach of the no-core shell-model theory to heavier nuclei and enables the description of spatially enhanced nuclear configurations. This is achieved by using a physically relevant symmetry-adapted basis, which exploits approximate symmetries that, we find, dominate …

For Every Mountain: A Phenomenological Study Examining The Experiences Of First-Generation, Low Socioeconomic Status, Black Males Excelling At Select Predominately White Institutions In Louisiana, Jovan Thomas

LSU Doctoral Dissertations

This study is an attempt to examine the academic experiences among low SES, first-generation Black males who are excelling at select PWI’s in Louisiana. The images created of Black men in our society often confine them to environments shaped by drugs, crime, athletics, and academic failure. The path to upward mobility or economic success for African American men is often filled with obstacles and roadblocks. For a period of decades, there has been much research dedicated to African American male academic success and first-generation college students, whereas, the focus on low SES, first-generation Black males who excel at Predominantly White …

Speciation And Hybridization In Jamaican-Endemic Streamertail Hummingbirds (Trochilus Polytmus And T. Scitulus), Caroline D. Judy

LSU Doctoral Dissertations

Streamertails hummingbirds (Trochilus polytmus and T. scitulus) are recently diverged sister taxa that appear to have speciated in situ on the island of Jamaica. They are distinguished by male bill color, a secondary sexual trait that is coral red in T. polytmus and jet black in T. scitulus. They hybridize in a narrow zone where their ranges meet in eastern Jamaica. In Chapter 2, I performed a formal population survey of T. scitulus to determine the size of the population, which was unknown. I determined that the total population contains well over 100,000 individuals despite its limited …

Early Speech Deterioration In Amyotrophic Lateral Sclerosis: A Case Study Of Newscaster Donna Britt, Emily Watkins

LSU Master's Theses

Abstract

Purpose: The aim of this study is to detect and track speech changes using acoustic and perceptual measures in an individual (a local newscaster) with amyotrophic lateral sclerosis (ALS) using data from before her diagnosis, around the time of her diagnosis, and after her diagnosis.

Methods: Six time points, ranging from 37 months around her diagnosis, were analyzed from one speaker with ALS. Three acoustic parameters were measured: articulation rate, acoustic vowel space, and the slope of the second formant. Additionally, two experts with more than 10 years of experience perceptually analyzed the speech samples on 17 characteristics using …

Toward Building Resilient, Sustainable, And Smart Infrastructure In The 21st Century, Aly Mousaad Aly

Faculty Publications

In recent years, as a result of significant climate change, stringent windstorms are becoming more frequent than before. Given the threat that windstorms bring to people and property, wind/structural engineering research is imperative to improve the resilience of existing and new infrastructure, for community safety and assets protection. The Windstorm Impact, Science and Engineering (WISE) research program at Louisiana State University (LSU) focuses on creating new knowledge applicable to the mitigation of existing and new infrastructure, to survive and perform optimally under natural hazards. To achieve our research goals, we address two imperious challenges: (i) characterization of realistic wind forces …

Finite Time Estimation Through A Continuous-Discrete Observer, Frédéric Mazenc, Saeed Ahmed, Michael Malisoff

Faculty Publications

We study two broad classes of nonlinear time-varying continuous-time systems with outputs. For the first class, we build an observer in the case where a state dependent disturbance affects the linear approximation. When the disturbances are the zero functions, our observer provides exact values of the state at all times larger than a suitable finite time, and it provides an approximate estimate when there are nonzero disturbances, so our observers are called finite time observers. We use this construction, which is of interest for its own sake, to design a globally exponentially stabilizing dynamic output feedback for a family of …

The Effects Of Pressure And Magnetic Field On Phase Transitions And Related Physical Properties In Solid State Caloric Materials, Ahmad Ikhwan Us Saleheen

LSU Doctoral Dissertations

Solid-state caloric effects, such as the magnetocaloric (MCE) and barocaloric (BCE) effects, may be utilized in future cooling technologies that are more efficient and environment-friendly. Large caloric effects often occur near phase transitions, especially near coupled first-order magnetostructural transitions (MST), and are initiated by external parameters, such as magnetic field or hydrostatic pressure. In this dissertation, the effects of pressure, temperature, and magnetic field on the phase transitions in three material systems are studied in order to elucidate how the respective caloric effects are affected.

In the first study, the realization of a coupled MST in a MnNiSi-based system through …

Social Class And Elementary Education: The Elementary Education Act Of 1870, Cameron Lowry

Honors Capstones

No abstract provided.

Origin Of Localization In Ti-Doped Si, Yi Zhang, R. Nelson, K. M. Tam, W. Ku, U. Yu, N. S. Vidhyadhiraja, H. Terletska, J. Moreno, M. Jarrell, T. Berlijn

Faculty Publications

Intermediate band semiconductors hold the promise to significantly improve the efficiency of solar cells but only if the intermediate impurity band is metallic. We apply a recently developed first principles method to investigate the origin of electron localization in Ti doped Si, a promising candidate for intermediate band solar cells. We compute the critical Ti concentration and compare it against the available experimental data. Although Anderson localization is often overlooked in the context of intermediate band solar cells, our results show that in Ti doped Si it plays a more important role in the metal insulator transition than Mott localization. …

I Am Complicated, And So Is My Blackness: A Trifecta Exploration Of Educational Spaces And Identity Development, Kala Burrell-Craft

LSU Doctoral Dissertations

Myriads of research studies have been written over the past 20 years highlighting the racial gap and disparities in educational opportunities and outcomes between Black and White students, but as revealed in a review of the literature, more studies need to be conducted that examine the intersection of race, space/place, and racial identity development. Using critical race theory as a framework, this study comprised of three separate, but related essays that explore the function of educational spaces in which Black Americans navigate, grow, and develop as it intersects with race, space/place, and identity development. Essay one is a critical narrative …