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Effect Of Surfactant, Oil:Water Ratio And Temperature On The Rheology Of Emulsion-Suspension Complex Fluids: Implications For Oil-Based Drilling Fluids, Gilles Landry Numkam

LSU Doctoral Dissertations

Drilling fluids are non-Newtonian mixtures that play a critical role in the timely and successful completion of oil and gas wells. In the particular case of offshore operations, proper design of drilling fluids is of paramount importance in the constant quest to lower break-even prices. Most downhole problems are directly or in-directly related to the rheological and physical properties of drilling fluids, thereby calling for a better understanding of the underlying changes of these properties with respect to drilling fluid composition and external conditions.

The current stance in the design of drilling fluids involves the selection of components and their …

Symmetries And Canonical Transformations In Nuclei, David Kekejian, Jerry P. Draayer, Kristina D. Launey

Faculty Publications

We begin with a brief historical overview of the importance of special symmetries in atomic nuclei, especially the symplectic symmetry. We then show how deforming the symplectic algebra through canonical transformations that are unitary can be used to describe the same physics that in a non-deformed picture requires huge model spaces in far smaller deformed spaces, a simplification that should proportionally reduce the complexity of using the symplectic symmetry in applications. The overarching objective is to exploit this strategy to probe more deeply into the (ab initio) structure of nuclei, short cutting a need to await the development of evermore …

Intelligent Identification For Rock-Mineral Microscopic Images Using Ensemble Machine Learning Algorithms, Jonathan Shi

Faculty Publications

It is significant to identify rock-mineral microscopic images in geological engineering. The task of microscopic mineral image identification, which is often conducted in the lab, is tedious and time-consuming. Deep learning and convolutional neural networks (CNNs) provide a method to analyze mineral microscopic images efficiently and smartly. In this research, the transfer learning model of mineral microscopic images is established based on Inception-v3 architecture. The four mineral image features, including K-feldspar (Kf), perthite (Pe), plagioclase (Pl), and quartz (Qz or Q), are extracted using Inception-v3. Based on the features, the machine learning methods, logistic regression (LR), support vector machine (SVM), …

The Tensile Root Strength Of Spartina Patens Varies With Soil Texture And Atrazine Concentration, Lauris O. Hollis, R. Eugene Turner

Faculty Publications

The widely used agricultural herbicide atrazine enters wetlands and may potentially affect wetland plants that provide critical reinforcement of soil strength and contribute to ecosystem stability in ways that may vary among soil types. We conducted greenhouse experiments using four levels of atrazine doses and three different soil textures to test for differences between control and experimental treatments and interactive effects of soil texture and atrazine exposure by using the tensile root strength of the coastal wetland emergent macrophyte Spartina patens as the response variable. The tensile root strength of S. patens was not affected after 50days of atrazine exposure …

Preface, Hui-Hsiung Kuo, George Yin

Communications on Stochastic Analysis

No abstract provided.

Non-Nested Monte Carlo Dual Bounds For Multi-Exercisable Options, Xiang Cheng, Zhuo Jin

Communications on Stochastic Analysis

No abstract provided.

Subdifferentials Of Value Functions In Nonconvex Dynamic Programming For Nonstationary Stochastic Processes, Boris S. Mordukhovich, Nobusumi Sagara

Communications on Stochastic Analysis

No abstract provided.

Euler-Maruyama Method For Regime Switching Stochastic Differential Equations With Hölder Coefficients, Dung T. Nguyen, Son L. Nguyen

Communications on Stochastic Analysis

No abstract provided.

Totalitarian Random Tug-Of-War Games In Graphs, Marcos Antón, Fernando Charro, Peiyong Wang

Communications on Stochastic Analysis

No abstract provided.

Anticipating Exponential Processes And Stochastic Differential Equations, Chii Ruey Hwang, Hui-Hsiung Kuo, Kimiaki Saitô

Communications on Stochastic Analysis

No abstract provided.

Action Functionals For Stochastic Differential Equations With Lévy Noise, Shenglan Yuan, Jinqiao Duan

Communications on Stochastic Analysis

No abstract provided.

Fisetin, A 3,7,3 ',4 '-Tetrahydroxyflavone Inhibits The Pi3k/Akt/Mtor And Mapk Pathways And Ameliorates Psoriasis Pathology In 2d And 3d Organotypic Human Inflammatory Skin Models, Konstantin G. Kousoulas

Faculty Publications

Psoriasis is a chronic immune-mediated skin disease that involves the interaction of immune and skin cells, and is characterized by cytokine-driven epidermal hyperplasia, deviant differentiation, inflammation, and angiogenesis. Because the available treatments for psoriasis have significant limitations, dietary products are potential natural sources of therapeutic molecules, which can repair the molecular defects associated with psoriasis and could possibly be developed for its management. Fisetin (3,7,3 ',4 '-tetrahydroxyflavone), a phytochemical naturally found in pigmented fruits and vegetables, has demonstrated proapoptotic and antioxidant effects in several malignancies. This study utilized biochemical, cellular, pharmacological, and tissue engineering tools to characterize the effects of …

Stochastic Process And Its Role In The Development Of The Financial Market: Celebrating Professor Chow's Long And Successful Career, Xisuo L. Liu

Communications on Stochastic Analysis

No abstract provided.

Hybrid Models And Switching Control With Constraints, Jose L. Menaldi, Maurice Robin

Communications on Stochastic Analysis

No abstract provided.

Stochastic Partial Differential Equation Sis Epidemic Models: Modeling And Analysis, Nhu N. Nguyen, George Yin

Communications on Stochastic Analysis

No abstract provided.

A Note On Immersion Intertwines Of Infinite Graphs, Matthew Barnes, Bogdan Oporowski

Faculty Publications

We present a construction of two infinite graphs G1 and G2, and of an infinite set f of graphs such that f is an antichain with respect to the immersion relation and, for each graph G in f, both G1 and G2 are subgraphs of G, but no graph properly immersed in G admits an immersion of G1 and of G2. This shows that the class of infinite graphs ordered by the immersion relation does not have the finite intertwine property.

Joint Geodetic And Seismic Analysis Of Surface Crevassing Near A Seasonal Glacier-Dammed Lake At Gornergletscher, Switzerland, Louis Garcia, Karen M. Luttrell

Faculty Publications

Seasonal lake Gornersee forms at the confluence of Gornergletscher and Grenzgletscher, Switzerland, and experiences outburst floods annually in midsummer. To study the interplay between lake drainage, glacier movement and crevasse activity, high-frequency seismometers and GPS receivers were deployed in networks near Gornersee during the summer ablation seasons of 2004, 2006 and 2007. We use a Rayleigh wave coherence method to locate 3289, 7939 and 4087 icequakes, respectively, primarily along well-defined surface crevasses. We calculate two-dimensional strains from triads of GPS stations and find mean differential strain rates of similar to 300 x 10(-6) d(-1) with diurnal variations up to 800 …

Combining Virtual Reality And Machine Learning For Enhancing The Resiliency Of Transportation Infrastructure In Extreme Events, Supratik Mukhopadhyay, Yimin Zhu, Ravindra Gudishala

Publications

Traffic management models that include route choice form the basis of traffic management systems. High-fidelity models that are based on rapidly evolving contextual conditions can have significant impact on smart and energy efficient transportation. Existing traffic/route choice models are generic and are calibrated on static contextual conditions. These models do not consider dynamic contextual conditions such as the location, failure of certain portions of the road network, the social network structure of population inhabiting the region, route choices made by other drivers, extreme conditions, etc. As a result, the model’s predictions are made at an aggregate level and for a …

Drivers And Impacts Of Water Level Fluctuations In The Mississippi River Delta: Implications For Delta Restoration, Matthew Hiatt, John W. Day, Robert V. Rohli, John Andrew Nyman

Faculty Publications

This review synthesizes the knowledge regarding the environmental forces affecting water level variability in the coastal waters of the Mississippi River delta and relates these fluctuations to planned river diversions. Water level fluctuations vary significantly across temporal and spatial scales, and are subject to influences from river flow, tides, vegetation, atmospheric forcing, climate change, and anthropogenic activities. Human impacts have strongly affected water level variability in the Mississippi River delta and other deltas worldwide. Collectively, the research reviewed in this article is important for enhancing environmental, economic, and social resilience and sustainability by assessing, mitigating, and adapting to geophysical changes …

Multicomponent Model Of Crustal Stress At Cajon Pass, Southern California With Implications For Stress Field Heterogeneity, Elliott Conley Helgans

LSU Master's Theses

Earthquake processes in plate boundary settings are chiefly controlled by the in situ crustal stress field. Knowledge of the relative importance of various active processes acting on a fault system is necessary to understand the mechanics of faulting. This is of extreme importance to the Cajon Pass region of southern California, which may function as an earthquake gate, imposing control on large multifault ruptures. We model the in situ stress field at seismogenic depth in Cajon Pass by balancing the orientation of the modern stress field inferred from earthquake focal mechanisms against the superposition of the far field tectonic driving …

Sub-Tidal Hydrodynamics Of The Multi-Inlet Lake Pontchartrain Estuary Influenced By Mississippi River Diversion And Wind Associated With Atmospheric Fronts, Wei Huang

LSU Doctoral Dissertations

In-situ observations and a Finite Volume Community Ocean Model (FVCOM) are used to investigate the cold front induced sub-tidal hydrodynamics of Lake Pontchartrain, a semi-enclosed low-salinity estuary with multiple inlets connecting to the open ocean. Observations show that the sub-tidal hydrodynamic responses are highly correlated with the meteorological parameters during cold front events. Model results indicate that, under barotropic conditions, the remote wind effect has the greatest contribution to the overall water level variation, while the local wind stress during cold front events determines the slope for the water level inside the estuary. An examination of a quasi-steady state force …

Modeling Chemical Reactivity In Aqueous And Organic Systems: From Electronic Structure Methods To Force Field Development, Caitlin Gibson Bresnahan

LSU Doctoral Dissertations

Modeling reactivity in chemical systems has evolved dramatically in line with the capabilities of modern computing. Despite the advances in computational ability, the level in which one can model a system depends on a number of factors including the region of reactivity, size of the system, level of sophistication required in the molecular description, and so on. Electronic structure methods allow for a detailed description of the potential energy surface and inherently include all essential physics required for reactivity to occur, however these methods are limited by their computational expense. On the other hand, force fields allow for an atomistic …

A Two-Step Classification Platform To Classify Construction Sounds To Enhance Real-Time Construction Zone Monitoring, Jayati Halder Jui

LSU Master's Theses

In recent years, sounds generated from equipment used at a construction site have been found to be useful in identifying construction activities and associated equipment usage providing insightful information regarding project status and hazard issues. This study proposes a Two-Step Neural Classifier (TSNC) for accurate classification of real world construction sounds. Experimental results from real world construction site audio data showed an average classification accuracy of 98% for TSNC compared to 91% average accuracy for an ordinary (one-step) Artificial Neural Network (ANN). The TSNC model is a hierarchical model that exploits the idea of creating disjoint subgroups of construction sounds …

Seasonal Variability Of Forces Controlling Sedimentation In The Sundarbans National Forest, Bangladesh, Carol A. Wilson, E. J. Bomer

Faculty Publications

Southwest Bangladesh, located on the Ganges-Brahmaputra-Meghna delta, is experiencing the impacts of sea level rise (SLR) due to processes at both the local and global scale. In particular, regional alterations of the hydrodynamic network, due to embankment construction, have drastically altered effective SLR, placing millions of inhabitants at risk of prolonged inundation, and threatening the world's largest continuous mangrove stand, the Sundarbans National Forest (SNF). In order to effectively employ landscape recovery solutions, an understanding of local sediment transport and deposition is critical. This field-based study investigates the sediment dynamics between the mangrove platform and tidal channels of the SNF …

Visualizing The Fate And Distribution Of Pahs In Spartina And Avicennia Tissues From Barataria Basin, La, Kristina Jeannette Sebastian

LSU Master's Theses

During crude oil spill events, vegetation in marsh environments sequester polycyclic aromatic hydrocarbons (PAHs) from the crude oil by partitioning from the air phase through the waxy cuticle on the leaf surface. Recent studies from Macondo oil-impacted marshes have demonstrated that cycling of low molecular weight petrogenic PAHs occurs through the cuticle and other leaf tissue. At present, our understanding of how PAHs travel through the cuticle is coarse and limited by grab samples across the entire leaf, which preventing a full understanding the dynamics of PAH cycling in this environment. Multiphoton (MP) confocal microscopy visualizes the distribution of PAHs …

Multiphase Cfd Modeling In Particle-Laden Flows, Zhizhong Ding

LSU Doctoral Dissertations

Multiphase modeling is prevalent and useful in solving problems involving multiphase interactions such as fluid and solid. Applications conclude but not limited to fluidized bed, hydraulic conveying, and many others. Modeling techniques with multiple scales can provide various states of details with diverse computational resources used. In this dissertation, two CFD multiphase models are used to disclose interaction details in the particulate system. Two-Fluid Model is used to solve pulsed fluidized bed problem and immersed boundary method based direct numerical method is used to solve particle’s behavior in shear flow. Getting a better understanding of these problems to help to …

Phase-Field Study Of Crack Nucleation And Propagation In Elastic–Perfectly Plastic Bodies, Stella Brach, Erwan Tanné, Blaise Bourdin, Kaushik Bhattacharya

Faculty Publications

Crack initiation and propagation in elastic–perfectly plastic bodies is studied in a phase-field or variational gradient damage formulation. A rate-independent formulation that naturally couples elasticity, perfect plasticity and fracture is presented, and used to study crack initiation in notched specimens and crack propagation using a surfing boundary condition. Both plane strain and plane stress are addressed. It is shown that in plane strain, a plastic zone blunts the notch or crack tip which in turn inhibits crack nucleation and propagation. Sufficient load causes the crack to nucleate or unpin, but the crack does so with a finite jump. Therefore the …

Comparison Of The Kinetic Parameters Of Escherichia Coli 0157:H7, Listeria Monocytogenes And Salmonella Typhimurium Derived From The Baranyi And Huang Models In A Chemically Defined Minimal Medium, Jose Isidro Fuentes

LSU Master's Theses

Microbial growth can be characterized by parameters such as lag time, growth rate, and maximum population density at any specific point of time. Mathematical models that predict microbial growth of foodborne pathogens are increasingly used in the food industry as a viable alternative to traditional methods of microbial enumeration. The Baranyi model has been widely used as the primary model of choice by many authors because of its performance and accuracy. The most recently developed Huang model has been less implemented and few comparisons between the Baranyi and Huang models have been made when modeling pathogenic growth. For this research, …

Coarse-Grained Models For Constant Ph Simulations Of Carboxylic Acids, Naeyma N. Islam, Arjun Sharma, Gaurav Gyawali, Revati Kumar, Steven W. Rick

Faculty Publications

© 2019 American Chemical Society. A model for carboxylic acids, in both the protonated and deprotonated states, is developed in which hydrogen interaction sites are not used and all interactions are short-ranged. A method for constant pH simulations, which exploits these features of the model, is developed. The constant pH method samples protonation states by making discrete Monte Carlo steps and is able to efficiently move between states in two steps. The method is applied to the polymer poly(methacrylic acid), a pH-responsive polymer that undergoes structural changes as a function of pH. The model is able to reproduce the structural …

Extendibility Limits The Performance Of Quantum Processors, Eneet Kaur, Siddhartha Das, Mark M. Wilde, Andreas Winter

Faculty Publications

Resource theories in quantum information science are helpful for the study and quantification of the performance of information-processing tasks that involve quantum systems. These resource theories also find applications in other areas of study; e.g., the resource theories of entanglement and coherence have found use and implications in the study of quantum thermodynamics and memory effects in quantum dynamics. In this paper, we introduce the resource theory of unextendibility, which is associated with the inability of extending quantum entanglement in a given quantum state to multiple parties. The free states in this resource theory are the k-extendible states, and the …