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Articles 1 - 30 of 71
Full-Text Articles in Physical Sciences and Mathematics
Abundance Trends And Environmental Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Lower Barataria And Caminada Bays, Louisiana, Cara Edina Miller
Abundance Trends And Environmental Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Lower Barataria And Caminada Bays, Louisiana, Cara Edina Miller
LSU Doctoral Dissertations
The paucity of research into the environmental requirements, stock membership, abundance and residency patterns of bottlenose dolphins (Tursiops truncatus) in coastal Louisiana creates difficulty in understanding how local ecosystems and threats (such as fishery interactions, habitat degradation and pollution) affect populations. This study combined fine-scale environmental measurements and photo-identification techniques to describe patterns of habitat usage and abundance of bottlenose dolphins in lower Barataria Basin from June 1999 to May 2002. In addition I investigated the validity and limitations of using mark-recapture models to estimate abundance from cetacean photo-identification data. Bottlenose dolphins were present year-round in a wide range of …
Splitter Theorems For 3- And 4-Regular Graphs, Jinko Kanno
Splitter Theorems For 3- And 4-Regular Graphs, Jinko Kanno
LSU Doctoral Dissertations
Let g be a class of graphs and ≤ be a graph containment relation. A splitter theorem for g under ≤ is a result that claims the existence of a set O of graph operations such that if G and H are in g and H≤G with G≠H, then there is a decreasing sequence of graphs from G to H, say G=G0≥G1≥G2...Gt=H, all intermediate graphs are in g, and each Gi can be obtained from Gi-1 by applying a single …
Parallel Molecular Dynamics Simulations Of Dynamics Of Oxidation And Reactive Wetting In Metal/Ceramic Systems, Gurcan Aral
Parallel Molecular Dynamics Simulations Of Dynamics Of Oxidation And Reactive Wetting In Metal/Ceramic Systems, Gurcan Aral
LSU Doctoral Dissertations
Oxidation of a flat aluminum (111) surface and the reactive wetting of the aluminum (Al) droplet on a flat alumina (α-Al2O3) surface are investigated by using parallel molecular-dynamics simulations with dynamic charge transfer among atoms on a microscopic length scale. The interatomic potential, based on the formalism of Streitz and Mintmire, allows atoms to vary their charges dynamically between anions and cations, when atoms move and their local environment is altered. We investigate the oxidation thickness as a function of time and the oxygen density which is 10-40 times that of the normal state (1 atm …
Machine Learning Techniques For Efficient Query Processing In Kowledge Base Systems, Kevin Paul Grant
Machine Learning Techniques For Efficient Query Processing In Kowledge Base Systems, Kevin Paul Grant
LSU Doctoral Dissertations
In this dissertation we propose a new technique for efficient query processing in knowledge base systems. Query processing in knowledge base systems poses strong computational challenges because of the presence of combinatorial explosion. This arises because at any point during query processing there may be too many subqueries available for further exploration. Overcoming this difficulty requires effective mechanisms for choosing from among these subqueries good subqueries for further processing. Inspired by existing works on stochastic logic programs, compositional modeling and probabilistic heuristic estimates we create a new, nondeterministic method to accomplish the task of subquery selection for query processing. Specifically, …
Influences On State-Level Policies For Wildfire Risk Reduction, Marios Anastasis Valiantis
Influences On State-Level Policies For Wildfire Risk Reduction, Marios Anastasis Valiantis
LSU Master's Theses
Wildland fires are part of the United State’s history and culture. The human dimension of State wildland fire management, - the relationship of people and wildland fire in America- is an important and driving force in how federal and state agencies respond to wildland fire, now and in the future. In many ways, the critical element for the management of wildland fire is the management of people, communities, and organizations. Explosive growth in the wildland-urban interface puts entire communities, their associated infrastructure and the socioeconomic fabric that holds communities together at a high risk from wildland fire. Year after year …
Surface Water Pesticide Contamination In The Upper Terrebonne Basin Of Louisiana, John S. Walther
Surface Water Pesticide Contamination In The Upper Terrebonne Basin Of Louisiana, John S. Walther
LSU Master's Theses
Triazine herbicides are the most heavily used pesticides in the United States. Atrazine and Simazine are the primary triazine herbicides used for broadleaf weed control in the production of corn, sugarcane, and sorghum. Recent monitoring studies of surface waters in the Upper Terrebonne Basin of Louisiana indicate elevated amounts of triazines are running off fields and entering drinking water supplies. Atrazine has been classified as a possible carcinogen by the United States Environmental Protection Agency. Recent epidemiological studies have revealed increases in breast cancer and pre-term births following exposure to triazines at levels detected in drinking water. Non-point source pollution …
Factors Affecting Participation In City Recycling Programs, Stacy Marie Lockhart
Factors Affecting Participation In City Recycling Programs, Stacy Marie Lockhart
LSU Master's Theses
Recycling consists of diverting or recovering materials from the solid waste stream that would otherwise end up returning to the environment as a potential source of pollution. These collected materials are then used as raw materials in the manufacture or assembly of a new product or package. Over the years the amount of municipal solid waste being generated per person has steadily increased. Waste disposal costs are also increasing, making recycling even more important. To address this issue cities are developing recycling policies or plans. The type of plan varies according to the area; as of this time there are …
A Stellar Parameter Calibration Of Iue Data For The Determination Of The Present Day Mass Function Of High Mass Stars, Kenneth Thomas Taylor
A Stellar Parameter Calibration Of Iue Data For The Determination Of The Present Day Mass Function Of High Mass Stars, Kenneth Thomas Taylor
LSU Master's Theses
A study of stellar atmosphere models and the photometric quantity R is presented here, with R being the ratio of the integrated de-reddened fluxes from the two wavelength regions of the International Ultraviolet Explorer (IUE) satellite cameras. The effective temperatures and surface gravities of the stellar atmospheres were calibrated against R and absolute magnitude, using stellar evolution tracks from the literature, and applied to over 156 LMC stars whose masses and mass function are then derived from the results. The results show that the effective temperatures and surface gravities of stars derived from R and absolute magnitude correlate well with …
Control Of Transport Dynamics In Overlay Networks, Qishi Wu
Control Of Transport Dynamics In Overlay Networks, Qishi Wu
LSU Doctoral Dissertations
Transport control is an important factor in the performance of Internet protocols, particularly in the next generation network applications involving computational steering, interactive visualization, instrument control, and transfer of large data sets. The widely deployed Transport Control Protocol is inadequate for these tasks due to its performance drawbacks. The purpose of this dissertation is to conduct a rigorous analytical study on the design and performance of transport protocols, and systematically develop a new class of protocols to overcome the limitations of current methods. Various sources of randomness exist in network performance measurements due to the stochastic nature of network traffic. …
Molecular-Dynamics Simulations Of Self-Assembled Monolayers (Sam) On Parallel Computers, Satyavani Vemparala
Molecular-Dynamics Simulations Of Self-Assembled Monolayers (Sam) On Parallel Computers, Satyavani Vemparala
LSU Doctoral Dissertations
The purpose of this dissertation is to investigate the properties of self-assembled monolayers, particularly alkanethiols and Poly (ethylene glycol) terminated alkanethiols. These simulations are based on realistic interatomic potentials and require scalable and portable multiresolution algorithms implemented on parallel computers. Large-scale molecular dynamics simulations of self-assembled alkanethiol monolayer systems have been carried out using an all-atom model involving a million atoms to investigate their structural properties as a function of temperature, lattice spacing and molecular chain-length. Results show that the alkanethiol chains tilt from the surface normal by a collective angle of 25o along next-nearest neighbor direction at 300K. At …
Synthesis, Characterization, And Application Of Water-Soluble Chiral Calix[4]Arene Derivatives In Spectroscopy And Capillary Electrokinetic Chromatography, Kim Hamilton
LSU Doctoral Dissertations
This dissertation is an account of the synthesis, characterization, and application of novel water-soluble chiral calixarenes in spectroscopy and capillary electrophoresis. It is divided into four sections. The first part describes the synthesis and nuclear magnetic resonance (NMR) characterization of four p-t-butylcalix[4]arenes bearing L-amino acid moieties on their lower rims (CX4-AA). The structure and conformation of the derivatives have been determined using one- and two-dimensional NMR techniques. Proton and carbon-13 spectra show that the derivatives are tetra-substituted and adopt a cone conformation. The preparation and characterization of silica-bonded calixarene stationary phases for capillary electrochromatography is also reported in Chapter 2. …
Design And Synthesis Of Handles For Solid-Phase Peptide Synthesis And Convergent Peptide Synthesis, Jose Giraldes
Design And Synthesis Of Handles For Solid-Phase Peptide Synthesis And Convergent Peptide Synthesis, Jose Giraldes
LSU Doctoral Dissertations
The recent popularity of methods for solid-phase peptide synthesis that use the 9-fluorenylmethyloxycarbonyl (Fmoc) group for Nα-amino protection has created a need for compatible anchoring linkages and handles. In an effort to develop mild new methods for use in solid-phase peptide synthesis (SPPS), a new ferrocene containing linker or “handle”, the 1’1-ferrocenyl carboxaldehyde handle was designed, synthesized, characterized and tested. This linker is analogous to those commercially available and developed by Barany. The ferrocenyl amine linker(FAL) releases C-terminal peptide amides upon acidolysis. Since the FAL handle is acid labile it is compatible with Fmoc and Nα-dithiasuccinoyl …
A Risk-Averse Strategy For Blackjack Using Fractional Dynamic Programming, Ryan A. Dutsch
A Risk-Averse Strategy For Blackjack Using Fractional Dynamic Programming, Ryan A. Dutsch
LSU Master's Theses
We present how blackjack is related to a discrete-time control problem, rather than a zero-sum game. Using the compiler Visual C++, we write a program for a strategy for blackjack, but instead of maximizing the expected value, we use a risk-averse approach. We briefly describe how this risk-averse strategy is solved by using a special type of dynamic programming called fractional dynamic programming.
Correlation Of Core Characteristics To Outcrop Upper Jackfork Group Turbidites, Degray Lake, Arkansas, Daniel James Golob
Correlation Of Core Characteristics To Outcrop Upper Jackfork Group Turbidites, Degray Lake, Arkansas, Daniel James Golob
LSU Master's Theses
Pennsylvanian age Jackfork Group cores from the DeGray Lake Dam and outcrop from the east wall of the DeGray Lake Spillway, Arkansas, provide an opportunity for a detailed study on the transport and depositional characteristics of a fine-grained, deep-water depositional system. Two phases of resedimentation processes are responsible for deposition of the sediments in the cores and the outcrop. Primary resedimentation processes transport terrigenous sediments from the shelf or basin edge into the middle fan environment, while secondary resedimentation alter the sediments after they are initially deposited in the environment. Debris flows, slurry flows, and high and low density turbidity …
Stock Price Modeling And Insider Trading Theory, Jessica J. Guillory
Stock Price Modeling And Insider Trading Theory, Jessica J. Guillory
LSU Master's Theses
The mathematical study of stock price modeling using Brownian motion and stochastic calculus is a relatively new field. The randomness of financial markets, geometric brownian motions, martingale theory, Ito's lemma, enlarged filtrations, and Girsanov's theorem provided the motivation for a simple characterization of the concepts of stock price modeling. This work presents the theory of stochastic calculus and its use in the financial market. The problems on which we focus are the models of an investor's portfolio of stocks with and without the possibility of insider trading, opportunities for fair pricing of an option, enlarged filtrations, consumptions, and admissibility. This …
Multileaf Collimator Positional Reproducibility Evaluated With A Two-Dimensional Diode Array, Kara King Ferachi
Multileaf Collimator Positional Reproducibility Evaluated With A Two-Dimensional Diode Array, Kara King Ferachi
LSU Master's Theses
When delivering the total dose via a sequence of small fields shaped by a multileaf collimator, it is important to consider leaf positional reproducibility. A small error in the leaf position can result in large dose errors to the entire field. This is true for both dynamic multileaf collimation and step and shoot delivery. The goal of this research project is to design a method of quality assurance that is easily reproducible, sensitive to small changes in leaf position, and requires minimal time on the part of the medical physicist to carry out. This paper describes a system of measurements …
Middle Miocene Grounding Events On The Ross Sea Outer Continental Shelf, Antarctica, Juan Manuel Chow
Middle Miocene Grounding Events On The Ross Sea Outer Continental Shelf, Antarctica, Juan Manuel Chow
LSU Master's Theses
The middle Miocene δ18O enrichments from deep-sea data and eustatic sea level falls are traditionally attributed to expansion of the East Antarctic Ice Sheet. Interpretations of such data have led many to conclude that the West Antarctic Ice Sheet (WAIS) was not well-developed until the late Miocene. In such a scenario, middle Miocene glaciation on the Ross Sea shelf would have had to be minimal, perhaps in the form of ice caps, to be consistent with proxy data. New seismic-stratigraphic analysis of the Ross Sea outer continental shelf suggests that at least five grounding events (ice sheet advances …
Detrital Tourmaline As An Indicator Of Provenance: A Chemical And Sedimentological Study Of Modern Sands From The Black Hills, South Dakota, David Brent Viator
Detrital Tourmaline As An Indicator Of Provenance: A Chemical And Sedimentological Study Of Modern Sands From The Black Hills, South Dakota, David Brent Viator
LSU Master's Theses
Detrital tourmaline has proven useful as a provenance indicator mineral of ancient sedimentary/metasedimentary units due to its presence in many rock types, chemical responsiveness to environments of formation, complex and variable chemical compositions, high resistance to chemical and mechanical weathering, and stability through diagenesis and metamorphism. This study further establishes detrital tourmaline as a provenance indicator mineral by examining the chemical and sedimentological relationships between modern detrital tourmalines in the sediments of the Black Hills, South Dakota, USA, and in situ tourmalines from southern Black Hills’ tourmaline-bearing metasedimentary rocks, granites, and rare-element enriched pegmatites. Results show that detrital tourmaline is …
Diffusion Of A Rodlike Virus In Complex Solutions, Randall Charles Cush
Diffusion Of A Rodlike Virus In Complex Solutions, Randall Charles Cush
LSU Doctoral Dissertations
Entanglement phenomena in concentrated polymer solutions remain an interesting and challenging problem. It is still unclear how entanglement onset affects polymer chain motion at small distance scales. One way to study such motion is to follow the diffusion of a probe particle while increasing the concentration of the polymer. Many such studies have been done using probes ranging from linear and star polymers to various colloidal particles; however, relatively few studies have used rodlike probes. Rodlike probes are potentially more interesting due to the added information that may be gained by following rotational as well as translational diffusion. The anisotropic …
Constraint Preserving Boundary Conditions For The Linearized Einstein Equations, Gioel Calabrese
Constraint Preserving Boundary Conditions For The Linearized Einstein Equations, Gioel Calabrese
LSU Doctoral Dissertations
The successful construction of long time convergent finite difference schemes approximating highly gravitating systems in general relativity remains an elusive task. The presence of constraints and the introduction of artificial time-like boundaries contribute significantly to the difficulty of this problem. Whereas in the absence of boundaries the Bianchi identities ensure that the constraints vanish during evolution provided that they are satisfied initially, this is no longer true when time-like boundaries are introduced. In this work we consider the linearization around the Minkowski space-time in Cartesian coordinates of the generalized Einstein-Christoffel system and analyze different kinds of boundary conditions that are …
Biomechanical Reconstruction Of The Appendicular Skeleton In Three North American Jurassic Sauropods, Ray Wilhite
Biomechanical Reconstruction Of The Appendicular Skeleton In Three North American Jurassic Sauropods, Ray Wilhite
LSU Doctoral Dissertations
Forelimb and hindlimb articulation, reconstructed musculature, and function were examined in Apatosaurus, Diplodocus, and Camarasaurus. A technique was developed using a Microscribe three-dimensional digitizer to capture external morphological data for skeletal reconstruction and determination of taxonomically useful features. The appendicular musculature of Alligator mississippiensis was dissected to determine form, function, origin, and insertion of muscles to aid in reconstruction of sauropod musculature. Contrary to the literature, M. caudofemoralis longus was found to originate primarily from the lateral surfaces of the proximal chevrons instead of the bodies and transverse processes of the caudals, demonstrating that chevron morphology is indicative of the …
A Comparison Of Life Histories And Ecological Aspects Among Snappers (Pisces: Lutjanidae), Fernando Martinez-Andrade
A Comparison Of Life Histories And Ecological Aspects Among Snappers (Pisces: Lutjanidae), Fernando Martinez-Andrade
LSU Doctoral Dissertations
An extensive search for data on life-history and ecological variables was conducted for a representative number of the species within the family Lutjanidae. After creating different databases and standardizing all data, these variables were examined in statistical, correlation and graphic analyses. Additionally, a series of Principal Component Analyses were used to examine patterns among variables. Life-history variables included age at length zero, asymptotic length, maximum length, longevity, asymptotic weight, length at maturity, age at maturity, reproductive life span, growth rate and mortality rate. Ecological variables included latitudinal and vertical distribution, habitat selection (represented by substrate type), and spawning seasons. The …
Toward A Global Microscopic Theory For Nuclear Structure: Mean Field Plus Random Phase Approximation Vs. Shell Model, Ionel Stetcu
Toward A Global Microscopic Theory For Nuclear Structure: Mean Field Plus Random Phase Approximation Vs. Shell Model, Ionel Stetcu
LSU Doctoral Dissertations
Our understanding of nuclear structure is built upon mean-field theories such as Hartree-Fock and time-dependent Hartree-Fock. The small-amplitude limit of the latter is the random phase approximation (RPA), which is widely used to model giant resonances in nuclei. Despite this popularity, RPA has been mostly validated against toy models; tests against complex models are scarce in the literature. We perform a thorough test of the RPA against full 0hw shell model (SM) calculations, including in our investigation binding energies, scalar ground-state observables, for which we develop a new method, and transition strengths. We allow deformed Hartree-Fock solutions and compare results …
Angle-Resolved Photoemission Study And Neutron Diffraction Measurements On Lasb2, Alice Acatrinei
Angle-Resolved Photoemission Study And Neutron Diffraction Measurements On Lasb2, Alice Acatrinei
LSU Doctoral Dissertations
LaSb2 has recently been found to have unusual magnetoresistive properties despite the fact that neither La nor Sb are magnetic. The resistance is anisotropic, and at high magnetic fields presents an anomaly that might be a result of a charge density transition. The magnetoresistance is anisotropic and linear, and the resistivity presents high relative changes when a magnetic field is applied. Discovered in 1954, LaSb2, as the rest of the light rare-earth diantimonides, was poorly studied. The anisotropic magnetic properties reported in 1998 by Bud'ko, Canfield and their collaborators make the series very interesting. A description of …
The Extinction Properties Of Reddened Galactic Ob Sightlines, Lynne Angela Valencic
The Extinction Properties Of Reddened Galactic Ob Sightlines, Lynne Angela Valencic
LSU Doctoral Dissertations
A solid understanding of dust grains and their extinction properties is needed to better remove the effects of extinction from data and to comprehend the nature of the processes which modify grains. This requires a large sample of Galactic sightlines, extending far beyond the solar neighborhood, sampling not only a large volume of space but also a wide variety of environments. To fulfill this requirement, a database of sightlines toward 426 young, reddened stars was constructed using extinction curves based on IUE spectra. The curves were fit and the Fitzpatrick-Massa (FM) parameters were found. FM parameters allow for a quantitative …
Massively Parallel Molecular Dynamics Simulations Of Crack-Front Dynamics And Morphology In Amorphous Nanostructured Silica, Cindy Lynn Rountree
Massively Parallel Molecular Dynamics Simulations Of Crack-Front Dynamics And Morphology In Amorphous Nanostructured Silica, Cindy Lynn Rountree
LSU Doctoral Dissertations
Atomistic aspects of dynamic fracture in amorphous and nanostructured silica are herein studied via Molecular dynamics (MD) simulations, ranging from a million to 113 million atom system. The MD simulations were performed on massivelly parallel computers using highly efficient multi-resolution algorithms. Crack propagation in these systems is accompanied by nucleation and growth of nanometer scale cavities up to 20 nm ahead of the crack front. Cavities coalesce and merge with the advancing crack to cause mechanical failure. Recent AFM studies in silica glasses confirm this scenario of fracture [1]. The morphology of the fracture surfaces is studied by calculating the …
Book Embeddings Of Graphs, Robin Leigh Blankenship
Book Embeddings Of Graphs, Robin Leigh Blankenship
LSU Doctoral Dissertations
We use a structural theorem of Robertson and Seymour to show that for every minor-closed class of graphs, other than the class of all graphs, there is a number k such that every member of the class can be embedded in a book with k pages. Book embeddings of graphs with relation to surfaces, vertex extensions, clique-sums and r-rings are combined into a single book embedding of a graph in the minor-closed class. The effects of subdividing a complete graph and a complete bipartite graph with respect to book thickness are studied. We prove that if n ≥ 3, …
On The Geometry And Topology Of Moduli Spaces Of Multi-Polygonal Linkages, Michael Edward Holcomb
On The Geometry And Topology Of Moduli Spaces Of Multi-Polygonal Linkages, Michael Edward Holcomb
LSU Doctoral Dissertations
The geometric, topological, and symplectic properties of moduli spaces (spaces of configurations modulo rotations and translations) of polygonal linkages have been studied by Kapovich, Millson, and Kamiyama, et. al. One can form a polygonal linkage by taking two free linkages and identifying initial and terminal vertices. This can be generalized so that one takes three free linkages and identifies initial and terminal vertices. Then one obtains a linkage which contains multiple polygons, any two of which have shared edges. The geometric and topological properties of moduli spaces of these multi-polygonal linkages are studied. These spaces turn out to be compact …
The Effects Of Sediment Grain Size And Oil Exploration On Microbial Atp Biomass, Eric Tyson Guilbeau
The Effects Of Sediment Grain Size And Oil Exploration On Microbial Atp Biomass, Eric Tyson Guilbeau
LSU Master's Theses
Adenosine triphosphate (ATP) is a unique biochemical indicator of active microbial biomass and its relationship to environmental conditions. Its assay in sediments is complicated, however, by adsorptive loss to the sediment matrix and subsequent interferences in the luciferin-luciferase assay by compounds released during the extraction process. Corrections must be applied to correct for these losses and we describe a novel approach using radioactive ATP to correct for ATP adsorption. The sediment matrix also plays a significant role in determining both the magnitude of the ATP pool and the extent of the ATP adsorptive loss. Coarser sediments were found to have …
Design And Synthesis Of Constrained Dipeptide Units For Use As Β-Sheet Promoters, Umut Oguz
Design And Synthesis Of Constrained Dipeptide Units For Use As Β-Sheet Promoters, Umut Oguz
LSU Doctoral Dissertations
The study of factors promoting beta-sheet formation has recently gained interest due to the suspected involvement of beta-sheets in brain degenerative diseases such as Alzheimer's disease (AD), Creutzfeldt-Jacob disease (CJD) and bovine spongiform encephalopathy. Understanding beta-sheet formation and the factors that stabilize beta-sheet structure may serve as a basis for future drug design. The extended structure of a beta-sheet can be stabilized by constrained amino acid analogs that are pre-organized to adopt the extended conformation. In this dissertation using innovative synthetic organic chemistry methods, two dipeptide units are designed and synthesized that are constrained to form the extended conformation and …