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Articles 3091 - 3120 of 3417
Full-Text Articles in Physical Sciences and Mathematics
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 …
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 …
Black Willow (Salix Nigra) Use In Phytoremediation Techniques To Remove The Herbicide Bentazon From Shallow Groundwater, Robert Mark Conger
Black Willow (Salix Nigra) Use In Phytoremediation Techniques To Remove The Herbicide Bentazon From Shallow Groundwater, Robert Mark Conger
LSU Doctoral Dissertations
Wetland environments have been impacted by the activities of man over the past several hundred years in North America. Industrialization into wetland areas has brought with it anthropogenic compounds that have been released into soils and groundwater. The use of phytoremediation to detoxify soil and groundwater began in the mid 1990's and has become a popular remediation technology. In 1994, a feasibility study for using phytoremediation in such an industrialized wetland area was conducted at a petrochemical facility at BASF Corporation, located about 20 kilometers south of Baton Rouge, Louisiana in Ascension Parish. The test site consisted of low level …
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 …
Synchrotron Radiation As A Probe Of Chemical Information Using Novel Experimental Configurations, George Farquar
Synchrotron Radiation As A Probe Of Chemical Information Using Novel Experimental Configurations, George Farquar
LSU Doctoral Dissertations
Determination of chemical information with synchrotron radiation is an area of great scientific interest, and expanding the range of available techniques is the topic of this dissertation. The experimental methods described herein allows for a significant advancement of the availability of subtle chemical information. This dissertation uses ionizing radiation to study three chemical systems. First, the l=3 shape resonance in CO is investigated using a cryogenically cooled gas jet. Shape resonant effects have been studied for many years. Previously, this was accomplished on the vibrational structure of molecules with a limited ability to determine the rotational substructure effects. A dramatic …
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 …
Genome Analysis: Mutation Analysis Using Near Infrared Laser-Induced Fluorescence (Nir-Lif) And Single Molecule Detection In Microfluidic Devices, Musundi Ben Wabuyele
Genome Analysis: Mutation Analysis Using Near Infrared Laser-Induced Fluorescence (Nir-Lif) And Single Molecule Detection In Microfluidic Devices, Musundi Ben Wabuyele
LSU Doctoral Dissertations
A number of genotyping methods have been developed for mutation analysis, each of which has its own unique advantage. DNA amplification via polymerase chain reaction (PCR) provides an unlimited supply of material for subsequent genetic analysis even in case where only a single copy of the DNA molecule is present in the sample. Research presented in this dissertation first examines the efficiency of in vitro amplification of single copy DNA with subsequent sequencing analysis of PCR product. The PCR products (amplicons) were investigated for possible alteration, distortions or mutations due to the amplification process. The sequencing data for single copy …
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 …
Analyzing The Impact Of Changing Software Requirements: A Traceability-Based Methodology, James Steven O'Neal
Analyzing The Impact Of Changing Software Requirements: A Traceability-Based Methodology, James Steven O'Neal
LSU Doctoral Dissertations
Software undergoes change at all stages of the software development process. Changing requirements represent risks to the success and completion of a project. It is critical for project management to determine the impact of requirement changes in order to control the change process. We present a requirements traceability based impact analysis methodology to predictively evaluate requirement changes for software development projects. Trace-based Impact Analysis Methodology (TIAM) is a methodology utilizing the trace information, along with attributes of the work products and traces, to define a requirement change impact metric for determining the severity of a requirement change. We define the …
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 …
Equations Of Parametric Surfaces With Base Points Via Syzygies, Haohao Wang
Equations Of Parametric Surfaces With Base Points Via Syzygies, Haohao Wang
LSU Doctoral Dissertations
Suppose $S$ is a parametrized surface in complex projective 3-space $mathbf{P}^3$ given as the image of $phi: mathbf{P}^1 imes mathbf{P}^1 o mathbf{P}^3$. The implicitization problem is to compute an implicit equation $F=0$ of $S$ using the parametrization $phi$. An algorithm using syzygies exists for computing $F$ if $phi$ has no base points, i.e. $phi$ is everywhere defined. This work is an extension of this algorithm to the case of a surface with multiple base points of total multiplicity k. We accomplish this in three chapters. In Chapter 2, we develop the concept and properties of Castelnuovo-Mumford regularity in biprojective spaces. …
Gravitational Radiation Detectability Of Supernova 1987a'S Remnant Fully Matched Filter For Double Resonant Gravitational Detector, Giovanni Santostasi
Gravitational Radiation Detectability Of Supernova 1987a'S Remnant Fully Matched Filter For Double Resonant Gravitational Detector, Giovanni Santostasi
LSU Doctoral Dissertations
Part I There is some observational evidence of the presence of a pulsating light source in the remnant of the supernova (SN) 1987A [1]. This source is considered to be a rotating neutron star. Fourier analysis of the light intensity of this source reveals a main narrow frequency peak and side bands that are understood as a modulation of the main sinusoidal signal. A particular model of the neutron star invokes a precessing object to explain the modulation. From the Fourier spectrum of the source and changes in the frequency value, we can determine important parameters of the spinning neutron …
The Kauffman Bracket Skein Module Of The Quaternionic Manifold, John Michael Harris
The Kauffman Bracket Skein Module Of The Quaternionic Manifold, John Michael Harris
LSU Doctoral Dissertations
In this work, we study the structure of the Kauffman bracket skein module of the quaternionic manifold over the field of rational functions. We begin with a brief survey of manifolds whose Kauffman bracket skein modules are known, and proceed in Chapter 2 by recalling the facts from Temperley-Lieb recoupling theory that we use in the proofs. In Chapter 3, using recoupling theory and with Mathematica's assistance, we index an infinite presentation of the skein module, and conjecture that it is five-dimensional. In Chapter 4, using a new set of relations, we prove that the skein module is indeed spanned …
Nitrogen Loading Into An Urban Estuary: Lake Pontchartrain (Louisiana, U.S.A.), R. Eugene Turner, Q. Dortch, Dubravko Justic, Erick M. Swenson
Nitrogen Loading Into An Urban Estuary: Lake Pontchartrain (Louisiana, U.S.A.), R. Eugene Turner, Q. Dortch, Dubravko Justic, Erick M. Swenson
Faculty Publications
We constructed a nitrogen loading budget for the Lake Pontchartrain watershed located north of New Orleans, Louisiana (U.S.A.). Water quality measurements, discharge estimates, and literature values were used to establish the annual and seasonal variations in loading rates for total nitrogen and nitrate. The relatively stable annual loadings (million kg N) are about 10× that of the pre-settlement nitrogen loading, and come from atmosphere (1.3), the watershed (7.8), pumped urban runoff from New Orleans (1.0), and leakage through the Bonnet Carré flood control structure (0.5–0.9). Relatively minor additional amounts come from nitrogen fixation in the Lake. Occasional openings of the …
Modification Of An Injection Molding Machine To Mold Micro Parts With A Liga Mold, Emil John Geiger
Modification Of An Injection Molding Machine To Mold Micro Parts With A Liga Mold, Emil John Geiger
Honors Theses
No abstract provided.
Review Of Tuxedo Park, Michael F. Russo
Explicit Multiplicative Relations Between Gauss Sums, Brian J. Murray
Explicit Multiplicative Relations Between Gauss Sums, Brian J. Murray
LSU Doctoral Dissertations
H.Hasse conjectured that all multiplicative relations between Gauss sums essentially follow from the Davenport-Hasse product formula and the norm relation for Gauss sums. While this is known to be false, very few counterexamples, now known as sign ambiguities, have been given. Here, we provide an explicit product formula giving an infinite class of new sign ambiguities and resolve the ambiguous sign in terms of the order of the ideal class of quadratic primes.
Synthesis And Study Of New Materials For The Visual Detection Of Biomolecules, Ming He
Synthesis And Study Of New Materials For The Visual Detection Of Biomolecules, Ming He
LSU Doctoral Dissertations
The visual determination of saccharides has been of interest for well over a century. Sugars are a relatively challenging class of compounds to analyze. They exhibit great structural similarity as well as transparency in the visible region. The sensing of specific saccharides could aid the monitoring of disease or industrial fermentation products. Herein I present new methods allowing for simple and rapid visual detection of sialic acid, fructose and a homologous series of prototypical neutral oligosaccharides, the linear maltodextrins, containing up to seven glucose residues. The new methods allow for selective color detection of fructose in a large excess of …
Experience-Based Language Acquisition: A Computational Model Of Human Language Acquisition, Brian Edward Pangburn
Experience-Based Language Acquisition: A Computational Model Of Human Language Acquisition, Brian Edward Pangburn
LSU Doctoral Dissertations
Almost from the very beginning of the digital age, people have sought better ways to communicate with computers. This research investigates how computers might be enabled to understand natural language in a more humanlike way. Based, in part, on cognitive development in infants, we introduce an open computational framework for visual perception and grounded language acquisition called Experience-Based Language Acquisition (EBLA). EBLA can “watch” a series of short videos and acquire a simple language of nouns and verbs corresponding to the objects and object-object relations in those videos. Upon acquiring this protolanguage, EBLA can perform basic scene analysis to generate …
Mode Specific Photoionization Dynamics In Polyatomic Molecules, Gerald Jeffery Rathbone
Mode Specific Photoionization Dynamics In Polyatomic Molecules, Gerald Jeffery Rathbone
LSU Doctoral Dissertations
The work presented in this dissertation presents new work on polyatomic photoionization. In these investigations, the broad range behavior of both allowed and forbidden vibrational modes in linear triatomic systems were studied to understand mode specific aspects of photoionization. The current study is made possible by the experimental strategy of exploiting high resolution photoelectron spectroscopy and the high brightness of third generation synchrotron radiation sources. The data is taken typically tens of eV’s past the ionization potential. The strategy that I employ is to probe alternative vibrational modes which are frequently affected differently following resonant ionization. Such vibrationally resolved data …
Capillary And Microdevice Electrophoretic Tools For Genetic Analyses: Heteroduplex Analysis For Tuberculosis Drug Susceptibility And Ligase Detection Reaction For Colorectal Cancer Detection, Gloria Thomas
LSU Doctoral Dissertations
The traditional format of electrophoresis, the slab gel, is quickly being replaced by capillary and microdevice platforms, which offer improvements in cost, resolution, speed, quantitation and automation in genetic analyses. These techniques also employ a variety of separation matrices while the slab gel is limited to agarose and polyacrylamide. The research presented here explores the use of these electrophoretic formats for the detection of single nucleotide mutations using two genetic models associated with human disease. Slab gel based heteroduplex analysis (HDA), a popular mutation scanning method, uses a specially designed universal heteroduplex generator (UHG) containing controlled variation to enhance the …
Hydrodynamics And Freshwater Diversion Within Barataria Basin, Dongho Park
Hydrodynamics And Freshwater Diversion Within Barataria Basin, Dongho Park
LSU Doctoral Dissertations
In order to understand the physical processes in the Barataria estuary, a previously developed two-dimensional, depth-integrated hydrodynamic model is applied to simulate estuarine processes. The equations for conservation of mass and momentum predict specific physical processes when forced by tidal and salinity variations at the open boundaries, wind forcing patterns, precipitation and evaporation over the model domain, and freshwater runoff as point sources. This study is focused on examining the impact of freshwater dispersion from the freshwater sources. Thus, a hydrologic model was developed to estimate runoff. Furthermore grid size was reduced, a new advective code added, and baroclinic effects …
Group Automorphisms And The Decomposition Of Plancherel Measures, David Slay
Group Automorphisms And The Decomposition Of Plancherel Measures, David Slay
LSU Doctoral Dissertations
In this paper, a natural action of the automorphisms of a group on the space of irreducible unitary representations is used to decompose the Plancherel measure on the dual space as an integral of measures on homogeneous spaces. Explicit decompositions are obtained for the cases of free 2 and 3-step nilpotent Lie groups. These results are obtained using direct integral decompositions, induced representations, the Mackey Machine, and measure theory on homogeneous spaces.
Exotic Integral Witt Equivalence Of Algebraic Number Fields, Changheon Kang
Exotic Integral Witt Equivalence Of Algebraic Number Fields, Changheon Kang
LSU Doctoral Dissertations
Two algebraic number fields K and L are said to be exotically integrally Witt equivalent if there is a ring isomorphism W(OK) ~ W(OL) between the Witt rings of the number rings OK and OL of K and L, respectively. This dissertation studies exotic integral Witt equivalence for totally complex number fields and gives necessary and sufficient conditions for exotic integral equivalence in two special classes of totally complex number fields.
Barium And Lithium In Foraminifera: Glacial-Interglacial Changes In The North Atlantic, Jenney M. Hall
Barium And Lithium In Foraminifera: Glacial-Interglacial Changes In The North Atlantic, Jenney M. Hall
LSU Doctoral Dissertations
The trace element content of calcareous foraminifera provides a powerful tool to the study of glacial-interglacial changes in the physical and chemical properties of the ocean. Foraminifera incorporate barium in direct proportion to its concentration in seawater. Using barium as a nutrient proxy, Ba/Ca in benthic Planulina wuellerstorfi is used to reconstruct changes in thermocline ventilation and mid-depth circulation in the North Atlantic during the last glacial and deglacial time. Rivers are concentrated in barium compared to surface seawater. Therefore, barium in planktonic Neogloboquadrina pachyderma is used to identify deglacial meltwater in the Arctic Ocean. Foraminiferal Li/Ca was analyzed to …
Tidal Dynamics In The Bab El Mandab Strait, Ewa Jarosz
Tidal Dynamics In The Bab El Mandab Strait, Ewa Jarosz
LSU Doctoral Dissertations
The Bab el Mandab Strait is where the transition occurs between two noticeably different tidal regimes: the Gulf of Aden, where tidal fluctuations are mixed and have a range in excess of 2 m, and the Red Sea, where the tides are principally semidiurnal and their range is less than 1 m. Within the Strait, observations collected between May of 1995 and July of 1997 indicate that tidal currents are a mixed type and dominant constituents are the K1 and M2. The vertical structure of the tidal currents is complicated, differs between semidiurnal and diurnal constituents, and …
On Properties Of Linear Control Systems On Lie Groups, Fabiana Cardetti
On Properties Of Linear Control Systems On Lie Groups, Fabiana Cardetti
LSU Doctoral Dissertations
In this work we study controllability properties of linear control systems on Lie groups as introduced by Ayala and Tirao in [AT99]. A linear control system _x0006_Σ Lie group G is defined by x' = X(x) + Σkj=1 ujYj(x), where the drift vector field X is an infinitesimal automorphism, uj are piecewise constant functions, and the control vectors Yj are left-invariant vector fields. Properties for the flow of the infinitesimal automorphism X and for the reachable set defined by _x0006_Σ are presented in Chapter 3. Under a condition similar to the Kalman …
On The Stabilization And Regularization Of Rational Approximation Schemes For Semigroups, Simone Flory
On The Stabilization And Regularization Of Rational Approximation Schemes For Semigroups, Simone Flory
LSU Doctoral Dissertations
In this work we discuss consistency, stability and convergence of rational approximation methods for strongly continuous semigroups on Banach spaces. The Lax-Chernoff theorem shows that in this setting consistency and stability assumptions are necessary to obtain strong uniform convergence of approximation methods. We investigate rational approximation methods for strongly continuous semigroups and their consistency properties, with special emphasis on A-stable methods and Padé-type approximations. In particular, we discuss the stability and convergence properties of these schemes, including the stability of the well-known and widely used Backward-Euler and Crank-Nicolson Schemes. Furthermore, we modify stabilization techniques developed by Hansbo, Larsson, Luskin, Rannacher, …
Artificial Peptides Containing Ca,A- Disubstituted Amino Acids: Synthesis, Conformational Studies, And Application As Β-Strand Mimics, Yanwen Fu
LSU Doctoral Dissertations
Short peptides containing Cα,α-dipropylglycine (Dpg) at alternating sequence positions were synthesized and examined for conformational behavior. Peptide assembly was performed using Fmoc-solid-phase chemistry where the coupling with PyAOP could be significantly enhanced at elevated temperature. Circular dichroism (CD) and NMR conformational studies revealed that incorporation of Dpg residues induced folded structures into peptides. It was observed that Dpg residues adopted helical conformation in a helix-promoting sequence. The resulting helical structure was comprised of consecutive β-turns whose structure was stabilized by salt bridge in aqueous solution. In this study, the preparation of sterically and polyfunctional Cα,α-disubstituted amino …