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Articles 1111 - 1140 of 1402
Full-Text Articles in Physical Sciences and Mathematics
Revolutionizing Genomic Analyses: Mutation Analyses Using Novel Enzyme-Based Assays With Laser-Induced Fluorescence And Polymeric Microfluidic Devices As Electrophoretic Platforms, Rondedrick Deshaun Sinville
Revolutionizing Genomic Analyses: Mutation Analyses Using Novel Enzyme-Based Assays With Laser-Induced Fluorescence And Polymeric Microfluidic Devices As Electrophoretic Platforms, Rondedrick Deshaun Sinville
LSU Doctoral Dissertations
Polymer-based microelectrophoresis was investigated to analyze known (mutation detection) and unknown (mutation scanning) low-abundant mutations in genomic DNA with high diagnostic value for colorectal cancers. For our mutation detection assays, point mutations in the K-ras oncogene were identified using the ligase detection reaction (LDR). For the mutation scanning assay, which searches for sporadic mutations, an EndoV-LDR assay was utilized with mutations in the p53 tumor suppressor gene used as a model. A poly(methylmethacrylate), PMMA, microchip filled with a 4% linear polyacrylamide (LPA) gel was used to electrophoretically sort products formed from LDRs, which produced oligonucleotides <65 bp in length. Using microchip electrophoresis with the LPA, a 44 bp ligation product was resolved from a 100-fold molar excess of unligated primers (25 bp) in approximately 120 s, which was ~17 times faster than conventional capillary gel electrophoresis. In order to simplify the electrophoretic process and further reduce development time, the LDR products were sorted in the absence of the sieving gel using free solution conjugate electrophoresis (FSCE). FSCE incorporated polyamide “drag-tags” onto LDR primers, which provided DNA fragment mobilities in free solution that were dependent upon their size. LDR/drag-tagged (LDR-dt) products could be formed in a multiplexed format for mutant-to-wild-type ratios as low as 1 to 100 with single base resolution. Separations were conducted using capillary array electrophoresis (CAE) and PMMA microchips filled with only a TRIS buffer. Analysis times for the LDR-dt products were less than 11 min using CAE and ~85 s for PMMA microchips with high reproducible migration times within and between microchips. PMMA-based microchips were also evaluated for the identification of sporadic mutations using an endonuclease V – LDR (Endo V/LDR) technique. Endo V cleaves heteroduplexed DNA one base 3’ of single-base mismatched sites as well as nicking DNA at some matched sites as LDR reseals miscleaved sites to reduce false positive signals. Results suggested that Endo V/LDR products from p53 mutations could be successfully separated and detected using a PMMA microfluidic chip filled with a sparsely cross-linked replaceable polyacrylamide gel in less than 6 min, which was approximately 10-fold shorter compared to CAE.
Rice Straw Fiber Polymer Composites: Thermal And Mechanical Performance, Fei Yao
Rice Straw Fiber Polymer Composites: Thermal And Mechanical Performance, Fei Yao
LSU Doctoral Dissertations
Rice straw fiber can be considered as important potential reinforcing filler for thermoplastic composite because of its lignocellulosic characteristics. It is thus of practical significance to understand and predict the thermal decomposition process of rice straw fibers. A method proposed by Málek, Šesták, and co-workers was used to investigate and model thermal decomposition process of common natural fibers with detailed analysis on rice straw system. Assuming a global model occurring within the entire degradation of natural fibers with consideration of fiber as one pseudo-component, model can be used to describe both isothermal and non-isothermal degradation process of most selected fibers …
Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry For The Analysis Of Collected Bioaerosols, Alton John Dugas
Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry For The Analysis Of Collected Bioaerosols, Alton John Dugas
LSU Doctoral Dissertations
The goal of this dissertation was to demonstrate collection, detection and identification of microorganisms from bioaerosols using offline matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the analysis of proteins. MALDI-MS intact bacteria techniques were adapted for use with an orthogonal MALDI quadrupole-time-of-flight mass spectrometer. Results indicate the instrument is capable of analyzing intact whole-cells. The first phase was to evaluate three bioaerosol samplers, an Andersen N6 single-stage impactor (AI), a cyclone impactor, and a vacuum filter system. The samplers collected test bioaerosols using a constructed bioaerosol exposure chamber (BEC). The BEC allowed all three samplers to operate in parallel. Each …
Limit On The Muon Neutrino Magnetic Moment And A Measurement Of The Ccpip To Ccqe Cross Section Ratio, Serge Arisitde Ouedraogo
Limit On The Muon Neutrino Magnetic Moment And A Measurement Of The Ccpip To Ccqe Cross Section Ratio, Serge Arisitde Ouedraogo
LSU Doctoral Dissertations
A search for the muon neutrino magnetic moment was conducted using the Mini- BooNE low energy neutrino data. The analysis was performed by analyzing the elastic scattering interactions of muon neutrinos on electrons. The analysis looked for an excess of elastic scattering events above the Standard Model prediction from which a limit on the neutrino magnetic could be set. In this thesis, we report an excess of 15.3}6.6(stat)}4.1(syst) elastic scattering events above the expected background. At 90% C.L., we derived a limit on the muon neutrino magnetic moment of 12.7~ 10−10ƒÊB. The other analysis reported in this thesis is a …
Dactyls Reveal Evolutionary Patterns In Decapod Crustaceans, Jeffrey Guy Agnew
Dactyls Reveal Evolutionary Patterns In Decapod Crustaceans, Jeffrey Guy Agnew
LSU Doctoral Dissertations
Because of their high preservation potential and uses in foraging and defense, decapod crustacean dactyls (movable fingers of claws) are potentially excellent test subjects for an ongoing debate concerning the relative importance of top-down (predators) and bottom-up (prey) controls on morphologic diversification and evolution. The utility of dactyls for inferring evolutionary patterns were evaluated using living and subfossil xanthoid crabs sampled from the southeast U.S. Atlantic and Gulf of Mexico coasts, and were used to: (1) distinguish the roles of selection and constraint on dactyl morphology through allometric and shape comparisons in the context of the crab’s phylogenetic relationships and …
Growth And Properties Of Metal-On-Metal Nanostructures: Ag On Cu(110) And Co On Ag(110), Indrajith Chandima Senevirathne
Growth And Properties Of Metal-On-Metal Nanostructures: Ag On Cu(110) And Co On Ag(110), Indrajith Chandima Senevirathne
LSU Doctoral Dissertations
Heteroepitaxial nanostructures have a diverse array of applications and show novel phenomena that arise from the exotic physics exhibited in reduced dimensions. We have investigated two nano-structured systems in order to gain insights into the dynamics of their nucleation, growth and have observed striking differences, due in part to a competition between lattice strain, surface and interfacial free energies. When Ag is deposited on clean, single-crystal Cu(110), it initially wets the surface with a (111) monolayer, and spontaneously nucleates nanowires as the coverage is increased. The nanowires nucleate at defects and step edges and grow aligned along the [1–10] direction. …
Designing Surface Chemistries For In Situ Afm Investigations Of Biomolecular Reactions With Proteins At The Nanoscale, Johnpeter Ndiangui Ngunjiri
Designing Surface Chemistries For In Situ Afm Investigations Of Biomolecular Reactions With Proteins At The Nanoscale, Johnpeter Ndiangui Ngunjiri
LSU Doctoral Dissertations
In situ atomic force microscopy (AFM) characterizations and lithography can be applied to investigate the orientation, reactivity and stability of protein molecules adsorbed on nanostructures of self-assembled monolayers at near-physiological conditions. Automated nanografting was used to fabricate regular arrays of nanopatterns of ù-functionalized n-alkanethiols with designated terminal chemistries. After writing nanopatterns, protein binding occurs selectively on carboxylate-terminated nanopatterns via covalent bonds that are formed using N-ethyl-N'(dimethylaminoporpyl)-carbodiimide and N-hydroxysuccinimide activation. The amine groups of lysine residues of proteins bond covalently to nanopatterns of carboxylate-terminated alkanethiol self-assembled monolayers, to form a robust surface attachment for sustained contact-mode AFM imaging during biochemical reactions. …
Swamp Ecology In A Dynamic Coastal Landscape: An Investigation Through Field Study And Simulation Modeling, Susanne Sigrid Hoeppner
Swamp Ecology In A Dynamic Coastal Landscape: An Investigation Through Field Study And Simulation Modeling, Susanne Sigrid Hoeppner
LSU Doctoral Dissertations
Increased flooding, nutrient and sediment deprivation, and saltwater intrusion have been implicated as probable causes of coastal swamp deterioration in the Mississippi Delta. An understanding of the interactive effects of these factors is required to enable successful planning of wetland restoration activities. I used field data collected from 2000 till 2005 at forty study sites to characterize the baseline conditions of the Maurepas swamp. I used a cluster analysis to identify four swamp habitat clusters, and characterized the clusters on the basis of soil properties, salinity, basal area, stem density, and other tree-related variables. ANOVA and related statistical techniques showed …
Synthesis And Surface Characterization Of Silica-Polypeptide Composite Particles, Erick Isael Soto-Cantu
Synthesis And Surface Characterization Of Silica-Polypeptide Composite Particles, Erick Isael Soto-Cantu
LSU Doctoral Dissertations
The synthesis and sequential surface characterization of silica-polypeptide composite particles is described. Nearly monodisperse colloidal silica cores were obtained by the alkaline hydrolysis of tetraethyl orthosilicate (TEOS). The hydrodynamic radius can be easily controlled in the range of ƒî 20-140 nm by the water/TEOS ratio in the starting reaction mixture. The surface of the synthesized silica cores was further passivated/functionalized (P/F) by a mixture of (3-aminopropyl) trimethoxysilane (APS) and methyl-trimethoxysilane (MTMS). The amino groups were quantified using UV-Vis spectrometry after reaction with ninhydrin. The use of zeta potential measurements of the P/F silica particles at low pH is presented as …
Fast Marching Methods - Parallel Implementation And Analysis, Maria Cristina Tugurlan
Fast Marching Methods - Parallel Implementation And Analysis, Maria Cristina Tugurlan
LSU Doctoral Dissertations
Fast Marching represents a very efficient technique for solving front propagation problems, which can be formulated as partial differential equations with Dirichlet boundary conditions, called Eikonal equation: $F(x)|\nabla T(x)|=1$, for $x \in \Omega$ and $T(x)=0$ for $x \in \Gamma$, where $\Omega$ is a domain in $\mathbb{R}^n$, $\Gamma$ is the initial position of a curve evolving with normal velocity F>0. Fast Marching Methods are a necessary step in Level Set Methods, which are widely used today in scientific computing. The classical Fast Marching Methods, based on finite differences, are typically sequential. Parallelizing Fast Marching Methods is a step forward for …
Incorporation Of Cα,Α-Disubstituted Amino Acids Into Model Peptide Systems: Conformational Analysis And Possible Applications As Therapeutic Agents, Marcus A. Etienne
Incorporation Of Cα,Α-Disubstituted Amino Acids Into Model Peptide Systems: Conformational Analysis And Possible Applications As Therapeutic Agents, Marcus A. Etienne
LSU Doctoral Dissertations
A diverse set of human diseases is associated with the misfolding of proteins into insoluble fibrillar structures that have predominantly β-sheet secondary structure. Thus it is imperative to elucidate the structural elements that contribute to β-sheet formation and stability. Peptides that autonomously form β-sheets are ideal models to study principles of protein folding and design. Gellman and coworkers first introduced an automonously folded β-hairpin (H-Arg-Tyr-Val-Glu-Val-Yyy-Xxx-Orn-Lys-Ile-Leu-Gln-NH2) that remained monomeric up to ~1 mM. Circular dichroism (CD) and nuclear magnetic resonance (NMR) analyses revealed that incorporation of non-stereogenic Aib-Xxx dipeptidyl sequences into i+1 and i+2 positions of a model peptide nucleates a …
A Novel Automated Approach Of Multi-Modality Retinal Image Registration And Fusion, Hua Cao
A Novel Automated Approach Of Multi-Modality Retinal Image Registration And Fusion, Hua Cao
LSU Doctoral Dissertations
Biomedical image registration and fusion are usually scene dependent, and require intensive computational effort. A novel automated approach of feature-based control point detection and area-based registration and fusion of retinal images has been successfully designed and developed. The new algorithm, which is reliable and time-efficient, has an automatic adaptation from frame to frame with few tunable threshold parameters. The reference and the to-be-registered images are from two different modalities, i.e. angiogram grayscale images and fundus color images. The relative study of retinal images enhances the information on the fundus image by superimposing information contained in the angiogram image. Through the …
Biotransformation Of Organic Wood Preservatives By Micro-Organisms, Diana Nasirumbi Obanda
Biotransformation Of Organic Wood Preservatives By Micro-Organisms, Diana Nasirumbi Obanda
LSU Doctoral Dissertations
Wood products are treated with biocides to prevent biodegradation by bacteria, fungi, and insects. Much attention is being directed towards testing of metal-free organic preservative systems. The major disadvantage of organics is that they are biotransformed by micro-organisms in soil and wood. This study explored the biotransformation of the fungicide tebuconazole by a bacteria species (Pseudomonas fluorescens), the mold (Trichoderma harzianum), the white rot fungus (Phanerochaete chrysosporium) and the brown rot (Meruliporia incrassata). After incubation of cultures spiked with tebuconazole, samples were analyzed for chemical remaining and metabolites. M. incrassata, T. harzianum, and the bacterium all cleaved the 1, 2, …
Syntheses And Evaluation Of Phthalocyanine Derivatives For Applications In Photodynamic And Boron Neutron Capture Therapies For Cancer, Hairong Li
LSU Doctoral Dissertations
Chapter I introduced the background of phthalocyanines including its physical properties and various synthetic methods of free-base and metallo-phthalocyanines. The background of PDT and BNCT was introduced and the objective of ideal sensitizers was described. Chapter II described the synthesis and characterization of a series of pyridiloxy-substituted zinc phthalocyanines with different length of alkyl groups. Pyridiloxy-substituted silica phthalocyanines bearing different associated axial ligands, were alkylated with methyl or PEG chains. Biological study was performed on these cationic pyridiloxy-substituted zinc phthalocyanines. Chapter III introduced the synthesis and photophysical properties of A3B-type zinc phthalocyanines conjugated with one or two cobalta-carborane cages. They …
Development Of New Stimuli-Responsive Vesicles Using A Novel Surfactant, Yuming Yang
Development Of New Stimuli-Responsive Vesicles Using A Novel Surfactant, Yuming Yang
LSU Doctoral Dissertations
Many amphiphilic molecules (surfactants) possess the ability to aggregate in aqueous solution to form thermodynamically stable aggregates that have potential for use as molecule containers and delivery systems in analytical or pharmaceutical applications. However, it is difficult to release the encapsulated molecules from these aggregates under a controllable manner, and this problem has dramatically limited the application of these aggregated systems. This study addresses this problem through fundamental structure modification by development of a novel redox stimuli-responsive amphiphile capable of forming vesicle aggregates. Aggregate structure can be adjusted through redox stimulation. The release of agents from the core of the …
Stochastic And Copula Models For Credit Derivatives, Chao Meng
Stochastic And Copula Models For Credit Derivatives, Chao Meng
LSU Doctoral Dissertations
We prove results relating to the exit time of a stochastic process from a region in N-dimensional space. We compute certain stochastic integrals involving the exit time. Taking a Gaussian copula model for the hitting time behavior, we prove several results on the sensitivity of quantities connected with the hitting times to parameters of the model, as well as the large-N behavior. We discuss the relationship of these results to certain credit derivative instruments. Relevant simulations are presented.
A Century Of Land Use And Water Quality In Watersheds Of The Continental U.S., Whitney P. Broussard Iii
A Century Of Land Use And Water Quality In Watersheds Of The Continental U.S., Whitney P. Broussard Iii
LSU Doctoral Dissertations
Human endeavors, particularly the agricultural and industrial activities of the last half century, now produce more biologically available nitrogen (N) than all other natural sources combined. The increased N availability can have consequences for the health of aquatic biota on the local, regional, and global scales. One manifestation of this problem is the formation of coastal hypoxic zones where terrestrial N loading creates eutrophic conditions in coastal waters. This dissertation examines a century of changes in land use and water quality to quantify the relationships between agricultural land use practices and riverine N yields in the Mississippi River Basin and …
Evidence For Symplectic Symmetry In Ab Initio No-Core Shell Model Results, Tomas Dytrych
Evidence For Symplectic Symmetry In Ab Initio No-Core Shell Model Results, Tomas Dytrych
LSU Doctoral Dissertations
Advances in the construction of realistic internucleon interactions together with the advent of massively parallel computers have resulted in a successful utilization of the ab initio approaches to the investigation of properties of light nuclei. The no-core shell model is a prominent ab initio method that yields a good description of the low-lying states in few-nucleon systems as well as in more complex p-shell nuclei. Nevertheless, its applicability is limited by the rapid growth of the many-body basis with larger model spaces and increasing number of nucleons. To extend the scope of the ab initio no-core shell model to heavier …
Nonperturbative Dynamics Of Strong Interactions From Gauge/Gravity Duality, Hovhannes Roman Grigoryan
Nonperturbative Dynamics Of Strong Interactions From Gauge/Gravity Duality, Hovhannes Roman Grigoryan
LSU Doctoral Dissertations
This thesis studies important dynamical observables of strong interactions such as form factors. It is known that Quantum Chromodynamics (QCD) is a theory which describes strong interactions. For large energies, one can apply perturbative techniques to solve some of the QCD problems. However, for low energies QCD enters into the nonperturbative regime, where different analytical or numerical tools have to be applied to solve problems of strong interactions. The holographic dual model of QCD is such an analytical tool that allows one to solve some nonperturbative QCD problems by translating them into a dual five-dimensional theory defined on some warped …
Chemical Analysis Of Polymer Blends Via Synchrotron X-Ray Tomography, Heath Alan Barnett
Chemical Analysis Of Polymer Blends Via Synchrotron X-Ray Tomography, Heath Alan Barnett
LSU Doctoral Dissertations
Material properties of industrial polymer blends are of great importance. X-ray tomography has been used to obtain spatial chemical information about various polymer blends. The spatial images are acquired with synchrotron X-ray tomography because of its rapidity, good spatial resolution, large field-of-view, and elemental sensitivity. The spatial absorption data acquired from X-ray tomography experiments is converted to spatial chemical information via a linear least squares fit of multi-spectral X-ray absorption data. A fiberglass-reinforced polymer blend with a new-generation flame retardant is studied with multi-energy synchrotron X-ray tomography to assess the blend homogeneity. Relative to other composite materials, this sample is …
Visual Language Representation For Use Case Evolution And Traceability, Coretta Willis Douglas
Visual Language Representation For Use Case Evolution And Traceability, Coretta Willis Douglas
LSU Doctoral Dissertations
The primary goal of this research is to assist non-technical stakeholders involved in requirements engineering with a comprehensible method for managing changing requirements within a specific domain. An important part of managing evolving requirements over time is to maintain a temporal ordering of the changes and to support traceability of the modifications. This research defines a semi-formal syntactical and semantic definition of such a method using a visual language, RE/TRAC (Requirements Evolution with Traceability), and a supporting formal semantic notation RE/TRAC-SEM. RE/TRAC-SEM is an ontological specification employing a combination of models, including verbal definitions, set theory and a string language …
Gas-Phase Formation Of Environmentally Persistent Free Radicals From Thermal Degradation Of Catechol, Hydroquinone, Phenols And Tobacco, Julien Gnonlonfoun Adounkpe
Gas-Phase Formation Of Environmentally Persistent Free Radicals From Thermal Degradation Of Catechol, Hydroquinone, Phenols And Tobacco, Julien Gnonlonfoun Adounkpe
LSU Doctoral Dissertations
Catechol, hydroquinone and Phenol are major constituents of the mainstream tobacco smoke. The toxicity of tobacco has been attributed to the ability of catechol and hydroquinone to undergo endogenous or exogenous redox cycling to form semiquinone type radicals responsible of Reactive Oxygen Species (ROS) formation. ROS such as hydroxyl radicals can cause severe oxidative stress on biological tissues and can provoke severe signaling pathways leading to cardiovascular and pulmonary dysfunctions and carcinogenesis. Given that semiquinone type radicals are organic radicals, characterized by their high instability and reactivity; it is somewhat surprising that they can live long enough mostly when associated …
Landscape Analysis Of Vegetation Change In Coastal Louisiana Following Hurricanes Katrina And Rita, Gregory Dean Steyer
Landscape Analysis Of Vegetation Change In Coastal Louisiana Following Hurricanes Katrina And Rita, Gregory Dean Steyer
LSU Doctoral Dissertations
Investigations of hurricane disturbances on coastal vegetated communities are common, but relatively few are comprehensive across broad geographic regions. The 2005 hurricanes, Katrina and Rita, exposed Louisiana coastal landscapes to physical modifications and extensive and prolonged flooding, resulting in measurable physicochemical changes. This research used remote sensing and field investigations to regionally assess (1) porewater salinity and sulfide impacts to and recovery of coastal Louisiana vegetation communities, and (2) the importance of mineral sediment deposition on accretionary processes. Hurricane effects were most direct and prominent in eastern Louisiana from Katrina and western Louisiana from Rita, compared to central Louisiana exposed …
Differential Geometry In Cartesian Closed Categories Of Smooth Spaces, Martin Laubinger
Differential Geometry In Cartesian Closed Categories Of Smooth Spaces, Martin Laubinger
LSU Doctoral Dissertations
The main categories of study in this thesis are the categories of diffeological and Fr\"olicher spaces. They form concrete cartesian closed categories. In Chapter 1 we provide relevant background from category theory and differentiation theory in locally convex spaces. In Chapter 2 we define a class of categories whose objects are sets with a structure determined by functions into the set. Fr\"olicher's $M$-spaces, Chen's differentiable spaces and Souriau's diffeological spaces fall into this class of categories. We prove cartesian closedness of the two main categories, and show that they have all limits and colimits. We exhibit an adjunction between the …
Exploring The Binding Of Amine And Sulfonamide Ligands In Rhenium(I) Tricarbonyl And Platinum(Ii) Complexes, Anna Maria Christoforou
Exploring The Binding Of Amine And Sulfonamide Ligands In Rhenium(I) Tricarbonyl And Platinum(Ii) Complexes, Anna Maria Christoforou
LSU Doctoral Dissertations
Platinum is the metal present in various classes of inorganic medicinal agents directed at important diseases such as cancer or viral infections. Several new Pt(II) complexes of polyamine ligands bearing a dansyl moiety linked by a sulfonamide group were prepared; in some cases the sulfonamide nitrogen formed a bond to Pt. The sulfonamido group donates strongly to Pt and places the dansyl group close to a vacant coordination position, allowing it to stack with bound guanine base (G) when G binds. The emission of the fluorophore decreases with decreasing distance to Pt. Metal nuclide radiopharmaceuticals contain a metal core and …
Properties Of Silica-Polypeptide Composite Particles, Jianhong Qiu
Properties Of Silica-Polypeptide Composite Particles, Jianhong Qiu
LSU Doctoral Dissertations
Studies of grafting polymer on surfaces with chemical bonds started in the 1970’s, but few projects have focused on grafting polypeptide on spherical particles. In this research, polypeptides poly(å-carbobenzyloxy-L-lysine) (PCBL) or poly(ã-benzyl-L-glutamate) (PBLG) were grafted on silica sphere surfaces by using the “grafting from” method. The polypeptide-grafted silica spheres are called SiPCPs. The growth of polypeptide chains as a function of monomer amount and reaction time was explored. The properties of a mixture of PBLG rod-like polymer and PBLG SiPCPs were investigated. At high concentrations of these two components, the phase behavior was studied. At low concentrations of PBLG, the …
Highly Correlated Lanthanide Intermetallic And Oxide Phases: Crystal Growth And Structure-Property Relationships, Jasmine N. Millican
Highly Correlated Lanthanide Intermetallic And Oxide Phases: Crystal Growth And Structure-Property Relationships, Jasmine N. Millican
LSU Doctoral Dissertations
Our primary research goals are to synthesize, characterize, and study the structure, dimensionality, and physical properties of new highly correlated electron materials. Intermetallic lanthanide and oxide phases are of great interest due to their fascinating array of structural features and physical property phenomena, such as heavy fermion behavior, superconductivity, and magnetism. The crystal growth, structure, and physical properties of several different classes of materials, such as the Ln-M-Ga (Ln = La, Ce, Pr, M = Ni, Pd), Yb5Pt9, and R2Ir2O7 (R = Pr, Eu) compounds, will be highlighted within. The Ln-M-Ga phases allow us to examine the influence of the …
The Application Of Controlled Radical Polymerization Processes On The Graft Copolymerization Of Hydrophobic Substituents Onto Guar Gum And Guar Gum Derivatives, Veronica Holmes
LSU Doctoral Dissertations
Guar gum is a naturally occurring polysaccharide; guar gum and its derivatives, such as carboxymethyl guar gum (CMG) are widely used in the oil and gas industry. A hydraulic fracturing fluid for rock formations to enhance oil recovery (EOR) is comprised of viscosifier, gelled CMG, and sand particles (proppants). The gel is mixed with proppant (sand) and pumped at high rate and high pressure into an oil/gas well to the hydrocarbon-producing zone. The applied pressure will force the rock formation to fracture allowing entry of the guar gel/sand mixture. The mixture then fills the resultant fracture. The viscosity of the …
Shelf-Margin Delta Morphology As A Paleo Sea Level Indicator: Implications On Late Quaternary Relative Sea-Level Changes In The Northeast Gulf Of Mexico, Swati Ghoshal
LSU Doctoral Dissertations
A new technique to determine relative sea level history at siliciclastic settings is proposed in this dissertation. The clinoform break (defined as the topset-foreset transition point) of the modern Mississippi River Delta shows a direct relationship with sea level elevation. The analysis of Holocene lobes 8 and 9 belonging to the St. Bernard delta complex of the Mississippi Delta suggests that delta clinoforms can be significantly modified by post-abandonment processes, and hence a detailed stratigraphic evaluation is necessary to determine whether the clinoform geometry is a result of wave erosion or any other post-abandonment processes. The strategy was tested on …
An Evaluation Of An Inshore Aquaculture Park For Sustainable Coastal Community Development, Vanesssa Maxwell
An Evaluation Of An Inshore Aquaculture Park For Sustainable Coastal Community Development, Vanesssa Maxwell
LSU Doctoral Dissertations
This dissertation addresses applying industrial park concepts to the development of aquaculture parks in public waters specifically for off-bottom triploid Easter oyster, Crassostrea virginica, culture. The objectives are to identify the permitting process, relevant agencies, and legislation needed to facilitate development of aquaculture parks in the Gulf of Mexico states, and test and analyze off-bottom oyster culture for commercial production of triploid oysters. Off-bottom culture can increase oyster production, but fouling organisms can reduce growth and survival rates. The Adjustable Longline System (ALS), commercially used in Australia, allows oyster bags to be suspended in the water column and positioned for …