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Articles 1 - 30 of 101
Full-Text Articles in Physical Sciences and Mathematics
Integrating Micro-Scale Separations To Matrix Assisted Laser Desorption And Ioniation Time Of Flight Mass Spectrometry (Maldi-Tof-Ms) For Protein Analysis, Harrison K. Musyimi
Integrating Micro-Scale Separations To Matrix Assisted Laser Desorption And Ioniation Time Of Flight Mass Spectrometry (Maldi-Tof-Ms) For Protein Analysis, Harrison K. Musyimi
LSU Doctoral Dissertations
This dissertation describes the integration of micro-scale separations to matrix assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI TOF MS) for protein analysis. MALDI MS provides unsurpassed accurate mass measurements of intact bio-molecules, for example peptides and proteins, which in turn generate high molecular specificity enabling the identity, function and structure of these molecules to be characterized. However, in order to realize the full potential of MS in proteomic studies, integrated sample processing on automated and high throughput platforms is required to address the complexity, diversity and the dynamic range of proteomic analysis. The work described here contributes towards …
Topics In Quantum Topology, Khaled Moham Qazaqzeh
Topics In Quantum Topology, Khaled Moham Qazaqzeh
LSU Doctoral Dissertations
In chapter 1, which represents joint work with Gilmer, we define an index two subcategory of a 3-dimensional cobordism category. The objects of the category are surfaces equipped with Lagrangian subspaces of their real first homology. This generalizes the result of [9] where surfaces are equipped with Lagrangian subspaces of their rational first homology. To define such subcategory, we give a formula for the parity of the Maslov index of a triple of Lagrangian subspaces of a skew symmetric bilinear form over R. In chapter 2, we find two bases for the lattices of the SU(2)-TQFT-theory modules of the torus …
Magnetic, Thermodynamic And Transport Properties Of The Magnetic Semiconductor Fe₁₋Xcoxs₂ And Superconducting Lasb₂, Song Guo
LSU Doctoral Dissertations
In recent years magnetic semiconductors have attracted a great deal of attention because it is thought that they can be used to generate spin polarized current in spintronics, an emerging field where the spin degree of freedom of charge carriers is utilized in microelectronic devices. In this dissertation work, we investigate the magnetic, thermodynamic, and transport properties of the magnetic semiconductor Fe1-XCoxS2 for x less than 0.14, the doping range where Insulator-to-Metal and paramagnetic-to-ferromagnetic transitions occur. We discovered that the Kondo effect is an important ingredient in the paramagnetic region of magnetic semiconductor Fe1-X …
Filippov's Operator And Discontinuous Differential Equations, Khalid Abdulaziz Alshammari
Filippov's Operator And Discontinuous Differential Equations, Khalid Abdulaziz Alshammari
LSU Doctoral Dissertations
The thesis is mainly concerned about properties of the so-called Filippov operator that is associated with a differential inclusion x'(t) ε F(x(t)) a.e. t ε [0,T], where F : Rn → Rn is given set-valued map. The operator F produces a new set-valued map F[F], which in effect regularizes F so that F[F] has nicer properties. After presenting its definition, we show that F[F] is always upper-semicontinuous as a map from Rn to the metric space of compact subsets of Rn endowed with the Hausdorff metric. Our main approach is to study the …
Circuits And Structure In Matroids And Graphs, Brian Daniel Beavers
Circuits And Structure In Matroids And Graphs, Brian Daniel Beavers
LSU Doctoral Dissertations
This dissertation consists of several results on matroid and graph structure and is organized into three main parts. The main goal of the first part, Chapters 1-3, is to produce a unique decomposition of 3-connected matroids into more highly connected pieces. In Chapter 1, we review the definitions and main results from the previous work of Hall, Oxley, Semple, and Whittle. In Chapter 2, we introduce operations that allow us to decompose a 3-connected matroid M into a pair of 3-connected pieces by breaking the matroid apart at a 3-separation. We also generalize a result of Akkari and Oxley. In …
Ontology-Based Methodology For Error Detection In Software Design, Allyson M. Hoss
Ontology-Based Methodology For Error Detection In Software Design, Allyson M. Hoss
LSU Doctoral Dissertations
Improving the quality of a software design with the goal of producing a high quality software product continues to grow in importance due to the costs that result from poorly designed software. It is commonly accepted that multiple design views are required in order to clearly specify the required functionality of software. There is universal agreement as to the importance of identifying inconsistencies early in the software design process, but the challenge is how to reconcile the representations of the diverse views to ensure consistency. To address the problem of inconsistencies that occur across multiple design views, this research introduces …
Nutrient Constraints On Plant Community Production And Organic Matter Accumulation Of Subtropical Floating Marshes, Guerry O., Jr. Holm Jr.
Nutrient Constraints On Plant Community Production And Organic Matter Accumulation Of Subtropical Floating Marshes, Guerry O., Jr. Holm Jr.
LSU Doctoral Dissertations
In the cycle of delta growth and decay, peat-forming wetlands span a time and space continuum. Later in the delta cycle, freshwater floating marshes become increasingly removed from external sediment subsidy and internal nutrient cycling controls plant productivity and organic matter accumulation. An interesting question is whether increased external nutrient loading can affect the basic processes that lead to peat formation—plant production and organic matter decomposition. I conducted several field studies to understand whether belowground organic matter accumulation and decomposition were affected with increased nutrient exposure; in addition, the plant community was monitored over three years. A laboratory soil respiration …
Evaluation Of Tcp Based Congestion Control Algorithms Over High-Speed Networks, Yaaser Ahmed Mohammed
Evaluation Of Tcp Based Congestion Control Algorithms Over High-Speed Networks, Yaaser Ahmed Mohammed
LSU Master's Theses
The Additive Increase Multiplicative Decrease (AIMD) algorithm of the Transport Control Protocol (TCP) had worked remarkably well over low speed networks and had guaranteed fairness to the users all over these years, but at present, the demands for transferring large quantities of data over very high-speed networks are increasing at a tremendous rate. Because of its AIMD algorithm to control its window growth function accompanied by a slow response function which is inadequate over high-speed links, TCP has been proven to underutilize the available network bandwidth and leave a considerable amount of unused bandwidth. To overcome this limitation of TCP, …
Application Of Polymeric Microfluidic Devices For Separation Of Single-Stranded Dna, Shawn Llopis
Application Of Polymeric Microfluidic Devices For Separation Of Single-Stranded Dna, Shawn Llopis
LSU Doctoral Dissertations
Microsystems targeted for DNA sequencing, especially those focused on electrophoretic separations, are rapidly proving their viability to genomic research, mimicking the progress made when capillary electrophoresis developed from miniaturizing slab gel electrophoresis techniques. Being the more recent electrophoretic separation platform, the commercial availability of microchip electrophoresis devices remains relatively limited. To this extent, high-aspect ratio microstructures formed in thermo plastics have been developed using rapid fabrication methods from molding tools designed for mass replication of high-aspect ratio microfeatures. In this work, the choice and compatibility of poly(methylmethacrylate) (PMMA) – the primary substrate for DNA separations in this work – was …
Porous Inorganic-Organic Materials Based On Beta-Diketone Ligands, Yixun Zhang
Porous Inorganic-Organic Materials Based On Beta-Diketone Ligands, Yixun Zhang
LSU Doctoral Dissertations
Synthesis and characterization of porous inorganic-organic materials have been studied mainly on two linear β-diketone multifunctional ligands: pyridine based pyacH and isocyanide based HacphNC. As a known ligand, the preparation of pyacH has been improved with higher yield. When pyacH reacts with Fe and Al metal salts, trigonal metal β-diketonate building blocks M(pyac)3 are produced. When pyacH reacts with zinc acetate, both trans and cis Zn(pyac)2 are produced, both isomers were isolated and characterized by single-crystal X-ray crystallography. Solutions of the trigonal building block Fe(pyac)3 generate various crystal structures on reaction with AgNO3 in CH3CN. When the concentration of AgNO3 …
Structural Characterization Of Poly(Heterocycles) Formed Using Oxidative Methods, Rebecca Marie Brauch
Structural Characterization Of Poly(Heterocycles) Formed Using Oxidative Methods, Rebecca Marie Brauch
LSU Doctoral Dissertations
This research focused on elucidation of structural information for conducting polymer systems using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The structure of conducting polymer systems has been found to directly influence their physical properties. Poly(pyrrole) and poly(thiophene) are two of the most widely studied conducting polymers due to their high electrical conductivity, stability in the doped state, low toxicity, and current/potential applications. The purpose of this research was to apply MALDI-TOF MS to heterocyclic conducting polymers, specifically those of pyrrole and thiophene, to investigate structural properties of these polymers, with the specific aim of determining end group and …
Effects Of Diesel-Fuel And Copper Contaminants On Benthic Microalgae, Soraya Silva
Effects Of Diesel-Fuel And Copper Contaminants On Benthic Microalgae, Soraya Silva
LSU Doctoral Dissertations
Salt marshes are dynamic, highly productive habitats and serve as nursery grounds for many commercially and economically important species. Benthic microalgae (BMA) are considered an important food source for benthos and provide the principal source of nutrition that fuels secondary production. Estuarine sediments around the world are a repository for many contaminants from anthropogenic sources. In particular, hydrocarbons and metals are ubiquitous contaminants in coastal systems. The primary goal of this study was to study the effects of diesel fuel and copper, alone and in combination, on the BMA assemblage from a coastal salt marsh. To achieve this objective, salt …
Numerical Techniques For Fresnel Diffraction In Computational Holography, Richard Patrick Muffoletto
Numerical Techniques For Fresnel Diffraction In Computational Holography, Richard Patrick Muffoletto
LSU Doctoral Dissertations
Optical holography can produce very realistic virtual images due to its capability to properly convey the depth cues that we use to interpret three-dimensional objects. Computational holography is the use of digital representations plus computational methods to carry out the holographic operations of construction and reconstruction. The large computational requirements of holographic simulations prohibit present-day existence of real-time holographic displays comparable in size to traditional two-dimensional displays. Fourier-based approaches to calculate the Fresnel diffraction of light provide one of the most efficient algorithms for holographic computations because this permits the use of the fast Fourier transform (FFT). The limitations on …
Factors Influencing The Participation In Environmental Stewardship Programs: A Case Study Of The Agricultural And Forestry Sectors In Louisiana, Carrie Castille Mendoza
Factors Influencing The Participation In Environmental Stewardship Programs: A Case Study Of The Agricultural And Forestry Sectors In Louisiana, Carrie Castille Mendoza
LSU Doctoral Dissertations
Considerable research has been conducted to evaluate the adoption of agricultural best management practices and their overall impact on improving environmental quality. However, limited studies have been conducted to evaluate the behavioral factors that influence the adoption of these practices in the context of educational programs The goal of this study is to determine the factors that influence farmer conservation behavior that might lead to an increased probability of improving agriculture and forestry watersheds. A conceptual model was developed to identify the: 1) identify landowner participation in watershed conservation projects, and 2) determine the factors influencing agriculture and forestry landowners …
The Impact Of Hypoxia On Mercury Methylation In Bottom Sediment Of Northern Gulf Of Mexico, Mei Huey Tan
The Impact Of Hypoxia On Mercury Methylation In Bottom Sediment Of Northern Gulf Of Mexico, Mei Huey Tan
LSU Master's Theses
Widespread concern has developed about high mercury content in fish in the Gulf of Mexico and adjacent estuaries and bays. Among the areas implicated as possible sources of the mercury that moves up the food chain from the methylmercury formed in sediments and anoxic waters is the seasonal hypoxic zone in the northern Gulf. This research was designed to determine if methylmercury formation is stimulated by the anaerobic sediment conditions accompanying the onset of summer hypoxia in the Gulf. Both field and laboratory studies were carried out. For the field study sediment samples were collected at three stations (i.e. C4, …
Salt Marsh Restoration With Sediment-Slurry Amendments Following A Drought-Induced, Large-Scale Disturbance, Angela Marie Schrift
Salt Marsh Restoration With Sediment-Slurry Amendments Following A Drought-Induced, Large-Scale Disturbance, Angela Marie Schrift
LSU Master's Theses
A large-scale, drought-induced disturbance occurred in Louisiana during the spring and summer of 2000. Approximately 100,000 acres of Spartina dominated marshes died-back and turned brown. This die-off caused considerable concern because in the absence of recovery dieback marshes can transform to mudflats, which can subside leading to open ponds. The state of Louisiana is attempting to restore some of the dieback marshes through the addition of sediment-slurries. The sediment-slurry generated significantly different marsh elevations: high elevation (mean and 95 % confidence interval: 29, 26 to 32 cm above ambient marsh), medium elevation (21, 19 to 24 cm), low elevation (14, …
Two-Dimensional Penalized Signal Regression For Hand Written Digit Recognition, Qing Tang
Two-Dimensional Penalized Signal Regression For Hand Written Digit Recognition, Qing Tang
LSU Master's Theses
Many attempts have been made to achieve successful recognition of handwritten digits. We report our results of using statistical method on handwritten digit recognition. A digitized handwritten numeral can be represented by an image with grayscales. The image includes features that are mapped into two-dimensional space with row and column coordinates. Based on this structure, two-dimensional penalized signal logistic regression (PSR) is applied to the recognition of handwritten digits. The data set is taken from the USPS zip code database that contains 7219 training images and 2007 test images. All the images have been deslanted and normalized into 16 x …
Resource Recovery Of Coal Bed Methane Formation Water, Catherine Elizabeth Bishop
Resource Recovery Of Coal Bed Methane Formation Water, Catherine Elizabeth Bishop
LSU Master's Theses
During the excavation of natural gas, petroleum hydrocarbon-polluted brine water, termed production water, is drawn from the coal bed methane formations (CBMF) along with the natural gas product. The water is drawn out in vast amounts and re-injected into the CBMF. In the Greater Rocky Mountain Region (GRMR) where water supplies are dwindling, the remediation of CBMF production water has become a high priority for maintaining agriculture, residential development and industrial expansion. The overall objective of this research was to demonstrate in laboratory and field pilot studies the efficacious merging of Immobilized Microbe BioReactor (IMBR) technologies for biodegradation/mineralization of organics …
Habitat Use By Nekton In A Saltmarsh Estuary Along A Stream-Order Gradient In Northeastern Barataria Bay, Louisiana, Pablo Granados-Dieseldorff
Habitat Use By Nekton In A Saltmarsh Estuary Along A Stream-Order Gradient In Northeastern Barataria Bay, Louisiana, Pablo Granados-Dieseldorff
LSU Master's Theses
Mesohaline estuarine regions in Louisiana play an important role in coastal ecosystems. To begin to understand how nektonic species and communities respond to environmental variables before habitat modification, I examined patterns of habitat use by fishes and decapod crustaceans in a seemingly pristine mesohaline system that drains into Bay Batiste, southeastern Louisiana. The study area was focused on a relatively unaltered core saltmarsh complex drained by intertidal and subtidal streams and it was representative of a larger surrounding system in terms of nekton community structure and associated environmental variables. Stratified monthly sampling (February – November 2004) along a stream-order gradient …
Study Of Reliable Data Communication In Wireless Sensor Networks, Ravilochan Shamanna
Study Of Reliable Data Communication In Wireless Sensor Networks, Ravilochan Shamanna
LSU Master's Theses
A distributed wireless sensor network consists of numerous tiny autonomous sensing nodes deployed across a wide geographical area. These sensor nodes self organize and establish radio communication links with the neighboring nodes to form multi-hop routing paths to the central base station. The dynamic and lossy nature of wireless communication poses several challenges in reliable transfer of data from the sensor nodes to the sink. There are several applications of sensor networks wherein the data collected by the sensors in the network are critical and hence have to be reliably transported to the sink. An example of such an application …
On Moment Conditions For The Girsanov Theorem, See Keong Lee
On Moment Conditions For The Girsanov Theorem, See Keong Lee
LSU Doctoral Dissertations
In this dissertation, the well-known Girsanov Theorem will be proved under a set of moment conditions on exponential processes. Our conditions are motivated by the desire to avoid using the local martingale theory in the proof of the Girsanov Theorem. Namely, we will only use the martingale theory to prove the Girsanov Theorem. Many sufficient conditions for the validity of the Girsanov Theorem have been found since the publication of the result by Girsanov in 1960. We will compare our conditions with some of these conditions. As an application of the Girsanov Theorem, we will show the nonexistence of an …
Population Boundaries And Gravitational-Wave Templates For Evolving White Dwarf Binaries, Ravi Kumar Kopparapu
Population Boundaries And Gravitational-Wave Templates For Evolving White Dwarf Binaries, Ravi Kumar Kopparapu
LSU Doctoral Dissertations
We present results from our analysis of double white dwarf (DWD) binary star systems in the inspiraling and mass-transfer stages of their evolution. Theoretical constraints on the properties of the white dwarf stars allow us to map out the DWD trajectories in the gravitational-wave amplitude-frequency domain and to identify population boundaries that define distinct sub-domains where inspiraling and/or mass-transferring systems will and will not be found. We identify for what subset of these populations it should be possible to measure frequency changes and, hence, directly follow orbit evolutions given the anticipated operational time of the proposed space-based gravitational-wave detector, LISA. …
Swamp Tours In Louisiana Post Hurricane Katrina And Hurricane Rita, Dawn Schaffer
Swamp Tours In Louisiana Post Hurricane Katrina And Hurricane Rita, Dawn Schaffer
LSU Master's Theses
Hurricanes Katrina and Rita made landfall in southern Louisiana during August and September 2005, respectively. Prior to these storms swamp tours were a popular nature-based tourism experience that entertained visitors while teaching them about local flora, fauna, and culture. The number of swamp tour businesses in the state was slowly increasing. The purpose of this study was to determine how many swamp tours were operating after the hurricanes, what type of damage they sustained, and how they repaired their businesses. Differences between those tours that remained open after the hurricanes and those that closed were also examined. A 3-phase mail …
Modeling The Effects Of Endocrine Disrupting Chemicals On Atlantic Croaker: Understanding Biomarkers And Predicting Population Responses, Cheryl Anne Murphy
Modeling The Effects Of Endocrine Disrupting Chemicals On Atlantic Croaker: Understanding Biomarkers And Predicting Population Responses, Cheryl Anne Murphy
LSU Doctoral Dissertations
A number of environmental stressors have been shown to interfere with reproductive and behavioral processes of fish by interfering with endocrine function. Most biomarkers of endocrine disturbance tend to be static measurements from dynamic systems making them difficult to evaluate within the context of an individual, or subtle effects that do not relate well to endpoints of ecological significance. I present an approach that uses a series of models, based on Atlantic croaker, to extrapolate laboratory results to indicators of individual and population health. First, I created a physiologically based model that simulates vitellogenesis in a female fish. The model …
Petrological And Geochemical Investigations Of Deep Sea Turbidite Sands In The Pandora And Moresby Troughs: Source To Sink Papua New Guinea Focus Area, Luke Jeremiah Patterson
Petrological And Geochemical Investigations Of Deep Sea Turbidite Sands In The Pandora And Moresby Troughs: Source To Sink Papua New Guinea Focus Area, Luke Jeremiah Patterson
LSU Master's Theses
The Moresby and Pandora Troughs of the northern Coral Sea are components of the deep-sea depositional system that is the ultimate sink for the Source to Sink Papua New Guinea (PNG) Focus Area. Cores collected from the R/V Melville during March-April 2004 reveal marine volcaniclastic and terrigenous turbidites deposited in these troughs during the Quaternary. Constraining the spatial, temporal, and provenance characteristics for these terrigenous sands through mineralogical, chemical, and textural analysis is the primary focus of this study. All cores contain thinly-bedded sandy turbidite packages interlayered with hemipelagic marls and typical centimeter-to-meter-thick turbidite sequences. The Moresby Trough core JPC22 …
Fabrication, Characterization And Properties Of Hiercchically Ordered Nanocomposites, Avinash Dundigalla
Fabrication, Characterization And Properties Of Hiercchically Ordered Nanocomposites, Avinash Dundigalla
LSU Doctoral Dissertations
The objectives of this research are to study the structure, morphology and properties of poly(ethylene-oxide) (PEO)-clay nanocomposites using various imaging techniques. Optical Microscopy, Scanning Electron Microscopy, Environmental Scanning Electron Microscopy and Atomic Force Microscopy are used to image structures on all length scales. Complementary scattering experiments are discussed along with preliminary differential scanning calorimetry and Fourier Transform Infrared spectroscopy results. In particular we investigated the multilayered structures of PEO-Laponite and PEO-Montmorillonite multilayered films made from solution. The shear orientation of a polymer-clay network in solution combined with simultaneous solvent evaporation leads to supramolecular multilayer formation in the film. The resulting …
Improved Abutment Dosimetry In Segmented-Field Electron Conformal Therapy, John Dudley Richert
Improved Abutment Dosimetry In Segmented-Field Electron Conformal Therapy, John Dudley Richert
LSU Master's Theses
Purpose: Segmented-field electron conformal therapy is characterized by dose heterogeneity due to unmatched penumbra of abutted fields of differing energy. The present work investigates the potential to decrease dose heterogeneity by approximately matching beam penumbra using energy-specific source-to-collimator distances (SCDs). It was hypothesized that a clinically practical, variable-SCD method that utilizes Cerrobend® custom inserts can deliver segmented-field electron conformal therapy in the energy range of 6-20 MeV with less than ±5% variation in dose spread in the abutment regions of hypothetical planning target volumes (PTVs), i.e. constrain the PTV dose to 85%-105%. Methods: A Varian 15x15-cm2 electron applicator was modified …
A Community Approach To Identifying Essential Fish Habitat Of Spotted Seatrout, Cynoscion Nebulosus, In Barataria Bay, La, Pamela Sharon Dawn Macrae
A Community Approach To Identifying Essential Fish Habitat Of Spotted Seatrout, Cynoscion Nebulosus, In Barataria Bay, La, Pamela Sharon Dawn Macrae
LSU Doctoral Dissertations
Louisiana wetlands are disappearing at a dramatic rate, providing an impetus for identifying essential fish habitat (EFH) in this region. The distribution, relative abundance, biomass, length and food web dynamics of spotted seatrout, Cynoscion nebulosus, as well as the fish assemblage structure were examined in Barataria Bay, LA, in relation to habitat type and physical/chemical properties of the water. All fish were collected from three sites located along a salinity gradient, each contained the three habitat types of interest: marsh edge, soft bottom and oyster shell, and were sampled monthly from May 2003 to May 2004 with gillnets. Habitat preference …
Ice Sheet Grounding Zone Deposits On Ross Sea Continental Shelf (Antarctica): Seismic Facies Analysis And P-Wave Reflectivity Attributes, Adeniyi Adewumi Saanumi
Ice Sheet Grounding Zone Deposits On Ross Sea Continental Shelf (Antarctica): Seismic Facies Analysis And P-Wave Reflectivity Attributes, Adeniyi Adewumi Saanumi
LSU Master's Theses
Subglacial till and overlying glaciomarine deposits are difficult to distinguish because the physical properties of subglacial till may vary depending on the drainage conditions of the rock directly beneath the ice sheet. Based on approximately 120 kilometers of multi-channel seismic data, detailed seismic facies analysis and amplitude variation with offset (AVO) analysis are carried out to examine the distribution of ice sheet grounding zone deposits on the continental shelf of the Northern Basin, Ross Sea (Antarctica) and infer the physical properties of interpreted subglacial till. Seismic facies analysis led to the differentiation of distinct sub-environments around a grounded ice sheet: …
Caliche As A Geologic Repository For Atmospheric Sulfate, Katie Jane Howell
Caliche As A Geologic Repository For Atmospheric Sulfate, Katie Jane Howell
LSU Master's Theses
Recent studies demonstrate that important information on sulfur source, oxidation pathway, transport pattern, and reaction kinetics of the oxidation reactions of reduced sulfur gases in the atmosphere may be uncovered by measuring multiple sulfur and oxygen isotope compositions of the oxidation product — secondary atmospheric sulfate (SAS). SAS from Earth’s distant past, however, is rarely preserved in the rock record because of its high solubility and small quantity. Caliche, a pedogenic carbonate formed in arid to semi-arid continental settings and common in the geologic record, could serve as a repository for ancient SAS. Two major groups of caliche samples: 1) …