Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

LSU Doctoral Dissertations

Discipline
Keyword
Publication Year

Articles 991 - 1020 of 1229

Full-Text Articles in Physical Sciences and Mathematics

Probing The Association Behavior Of Hydrophobic Organic Compounds With Dissolved Humic Materials, Hadi M. Marwani Jan 2007

Probing The Association Behavior Of Hydrophobic Organic Compounds With Dissolved Humic Materials, Hadi M. Marwani

LSU Doctoral Dissertations

The association mechanism between hydrophobic organic compounds (HOC) and dissolved humic materials (DHM) has continued to be one of the interesting areas in environmental applications. The goal of the research reported in this dissertation is to investigate the association behavior of HOC with DHM. The first part of this research involves steady-state fluorescence measurements of these multi-component systems to study the effect of DHM content on the association mechanism of HOC, in particular using pyrene as a model. Results showed that steady-state fluorescence alone may not provide enough information about the quenching mechanism of pyrene with DHM. Lifetime based fluorescence …

Go to article

Interactions Of The Triaquatricarbonylrhenium(I) Cation With Nucleotides And Other N-Donor Ligands, Kristie Marie Adams Jan 2007

Interactions Of The Triaquatricarbonylrhenium(I) Cation With Nucleotides And Other N-Donor Ligands, Kristie Marie Adams

LSU Doctoral Dissertations

Transition metal centers possessing an octahedral geometry are useful for understanding the natural role of metal ions in biology. Complexes based on such metals might improve upon the widely used square planar Pt(II) anticancer drug cisplatin, cis-[Pt(NH3)2Cl2]. The octahedral triaquatricarbonylrhenium(I) cation, fac-[Re(CO)3(H2O)3]+, has been shown to possess anticancer activity. Furthermore, Re(I) complexes containing unstable rhenium isotopes have found utility as radiodiagnostic and radiotherapeutic agents. Thus, this work focuses on elucidating the fundamental coordination chemistry of fac-[Re(CO)3(H2O)3]+ …

Go to article

Synthesis Of Quaternary Dendronized Cellulose Derivatives And Their Potential Biological Applications, Changde Zhang Jan 2007

Synthesis Of Quaternary Dendronized Cellulose Derivatives And Their Potential Biological Applications, Changde Zhang

LSU Doctoral Dissertations

In this dissertation, novel dendronized cellulose derivatives with biodegradable backbones were created by using sodium carboxymethyl cellulose (CMC) as the starting material. CMC was first transformed into its corresponding tetrabutyl ammonium salt, which reacted with 2-chloro-N-methylpyridinium iodide (CMPI) to produce an activated ester of [2-(N-methyl pyridium) carboxymethyl cellulose] iodide (MPCMCI). The reaction of MPCMCPI and di-tert-butyl 4-[2-(ter-butoxycarbonyl)ethyl]-4-aminoheptanedicarboxylate (BA) produced a new derivative with BA dendron elaborated on cellulose backbone (CMCBA). The degree of substitution (DS) of CMCBA was adjusted by controlling the relative concentration of CMPI and by choosing CMC with different DS or different molecular weights. Thermogrametric analysis (TGA) …

Go to article

Synthesis And Evaluation Of Derivatives And Analogs Of Xanthene Dyes, Xiangyang Xu Jan 2007

Synthesis And Evaluation Of Derivatives And Analogs Of Xanthene Dyes, Xiangyang Xu

LSU Doctoral Dissertations

Xanthene dyes are one of the oldest synthetic dyes. Fluorescein was first synthesized by von Baeyer in 1871. Since its discovery, it has been extensively studied. Fluorescein can exist as four different ionic forms (cationic form, neutral form, monoanionic form and dianionic form). Under physiological conditions (pH 7.4), fluorescein mainly exists as the dianionic form which grants it large quantum yield and excellent solubility in water. This renders fluorescein and its derivatives useful for studies in biological media. Cysteine (Cys) and homocysteine (Hcy) are of the few amino acids which contain sulfur and both of them are believed to be …

Go to article

Highly Correlated Lanthanide Intermetallic And Oxide Phases: Crystal Growth And Structure-Property Relationships, Jasmine N. Millican Jan 2007

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 …

Go to article

Stereochemical And Regiochemical Trends In The Selective Spectrophotometric Detection Of Biological Molecules, Shan Jiang Jan 2007

Stereochemical And Regiochemical Trends In The Selective Spectrophotometric Detection Of Biological Molecules, Shan Jiang

LSU Doctoral Dissertations

Useful mechanistic studies to date concerning sugar detection by arylboronic acid chemosensors have mainly involved the elucidation of equilibrium constants and the role of boron-nitrogen interactions in signal transduction. However, several discreet sugarboronate complexes exist in solution. This is due to the complex equilibria between isomeric species of even the simplest monosaccharides. Relatively few reports have been devoted to a systematic study of the structures of each of the corresponding individual sugar-boronate complexes. We have investigated some of the precise regio- and stereochemical features of the various equilibrating sugar isomers that induce selective signal transduction. As a result of this …

Go to article

Mass Transfer And Evolution Of Compact Binary Stars, Vayujeet Gokhale Jan 2007

Mass Transfer And Evolution Of Compact Binary Stars, Vayujeet Gokhale

LSU Doctoral Dissertations

We present a study of key aspects of the evolution of binary stars with emphasis on binaries consisting of two white dwarf stars. The evolution of such systems is driven by the loss of angular momentum by gravitational wave radiation. Effects like mass transfer and other modes of angular momentum loss and redistribution influence the evolutionary fate of the binary, and can lead to a merger, the tidal disruption of one of the components or its survival as a long-lived AM Canum Venaticorum (AM CVn) type system. Our study takes into account some of these effects; like mass loss, tides, …

Go to article

Wood Liquefaction In The Presence Of Phenol With A Weak Acid Catalyst And Its Potential For Novolac Type Wood Adhesives, Hui Pan Jan 2007

Wood Liquefaction In The Presence Of Phenol With A Weak Acid Catalyst And Its Potential For Novolac Type Wood Adhesives, Hui Pan

LSU Doctoral Dissertations

Wood liquefaction was conducted using phenol as a reagent solvent with oxalic acid as a catalyst. A series of studies were done on liquefied wood, liquefied wood residues, novolac-type liquefied wood resins, and bio-composites fabricated from liquefied wood resin. The results of the liquefied wood residue characterization revealed that the liquefaction reactions conducted in different reaction vessels underwent different liquefaction mechanisms. The crystallinity indexes of the liquefied wood residues were higher than that of the original wood, indicating that the amorphous lignin was the most susceptible component in wood to the liquefaction reaction. Fe2+ and Fe3+ ions were found to …

Go to article

Application-Specific Reliable Data Transfer In Wireless Sensor Networks, Damayanti Datta Jan 2007

Application-Specific Reliable Data Transfer In Wireless Sensor Networks, Damayanti Datta

LSU Doctoral Dissertations

A wireless sensor network (WSN) is a collection of sensor nodes and base stations connected via wireless medium. It sends data collected from the nodes to the base stations for generating information. The size and low cost of the sensor nodes as well as the WSN's ability to connect without wired links are its key advantages which enable it to be deployed in hostile or inaccessible environments at low cost. However, WSNs suffer from high data loss due to the inherent weaknesses in a wireless transmission medium, transmission problems in hostile environments due to human interference, etc. and node failures …

Go to article

Exploring The Quark-Gluon Content Of Hadrons: From Mesons To Nuclear Matters, Hrayr Hamlet Matevosyan Jan 2007

Exploring The Quark-Gluon Content Of Hadrons: From Mesons To Nuclear Matters, Hrayr Hamlet Matevosyan

LSU Doctoral Dissertations

Even though Quantum Chromodynamics (QCD) was formulated over three decades ago, it poses enormous challenges for describing the properties of hadrons from the underlying quark-gluon degrees of freedom. Moreover, the problem of describing the nuclear force from its quark-gluon origin is still open. While a direct solution of QCD to describe the hadrons and nuclear force is not possible at this time, we explore a variety of developed approaches ranging from phenomenology to first principle calculations at one or other level of approximation in linking the nuclear force to QCD. The Dyson Schwinger formulation (DSE) of coupled integral equations for …

Go to article

Elementary Reactions Involved In Pollutant-Forming Mechanisms, Cheri Ann Mcferrin Jan 2007

Elementary Reactions Involved In Pollutant-Forming Mechanisms, Cheri Ann Mcferrin

LSU Doctoral Dissertations

The reactions of the hydroxyl radical (OH) with molecular chlorine (Reaction 1), methane (Reaction 2), and propane (Reaction 3) have been studied experimentally using a pulsed laser photolysis/pulsed-laser-induced fluorescence technique over wide ranges of temperatures (297-826, 298-1009, and 296-908 K, respectively) and at pressures between 6.68 and 24.15 kPascals. The rate coefficients for these reactions exhibit no dependence on pressure and exhibit positive temperature dependences that can be represented with modified three-parameter Arrhenius expressions within their corresponding temperature ranges: k1 = 3.59 x 10-16T1.35exp(-745K/T)cm3molecule-1sec-1, k2 = 3.82 x 10-19T2.38 exp(-1136K/T)cm3molecule-1sec-1, and k3 = 6.64 x 10-16T1.46 exp(-271K/T)cm3molecule-1sec-1. For the OH …

Go to article

Shear Responses Of Poly(Ethylene Oxide)-Laponite Nanocomposite Hydrogels, Elena Loizou Jan 2007

Shear Responses Of Poly(Ethylene Oxide)-Laponite Nanocomposite Hydrogels, Elena Loizou

LSU Doctoral Dissertations

This research seeks to understand the structure and shear responses of poly(ethylene oxide)-Laponite nanocomposite hydrogels and to relate the macroscopic physical properties to the nanoscopic structural changes. Understanding that relationship is necessary, in order to tailor material properties to specific applications. Information on the structure at rest on multiple length scales was obtained by combining microscopic and neutron scattering techniques. The structural changes that occur in response to a shear field were explored using rheology and neutron scattering. These structures were examined as a function of polymer molecular weight, polymer and clay concentrations, and sample preparation method. While the sample …

Go to article

Wet And Dry Aging Of Polymer-Asphalt Blends: Chemistry And Performance, Ionela Chiparus Glover Jan 2007

Wet And Dry Aging Of Polymer-Asphalt Blends: Chemistry And Performance, Ionela Chiparus Glover

LSU Doctoral Dissertations

A PG 76-22 Polymer Modified Asphalt Cement composition was subjected in the laboratory to accelerated aging using both a standard Thin Film Oven Test and a Pressure Aging Vessel. Conditions simulating wet atmospheres (PAV in saturated water vapors) as well as very long service terms (multiple dry and wet PAV operations) were studied. A Rotating Cylinder Aging Test has been employed as an alternate asphalt aging technique using the same PMAC composition in order to observe the initial phases of the oxidative aging process. The data provided by this technique was correlated with the actual aging in the field of …

Go to article

Knowledge-Based Methods For Automatic Extraction Of Domain-Specific Ontologies, Janardhana R. Punuru Jan 2007

Knowledge-Based Methods For Automatic Extraction Of Domain-Specific Ontologies, Janardhana R. Punuru

LSU Doctoral Dissertations

Semantic web technology aims at developing methodologies for representing large amount of knowledge in web accessible form. The semantics of knowledge should be easy to interpret and understand by computer programs, so that sharing and utilizing knowledge across the Web would be possible. Domain specific ontologies form the basis for knowledge representation in the semantic web. Research on automated development of ontologies from texts has become increasingly important because manual construction of ontologies is labor intensive and costly, and, at the same time, large amount of texts for individual domains is already available in electronic form. However, automatic extraction of …

Go to article

Exploring The Binding Of Amine And Sulfonamide Ligands In Rhenium(I) Tricarbonyl And Platinum(Ii) Complexes, Anna Maria Christoforou Jan 2007

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 …

Go to article

The Spectral And Photophysical Characterization Of Water Solubilizing Metal Phthalocyanines For Highly Sensitive Detection In Biological Studies, Vera Tamisha Verdree Jan 2007

The Spectral And Photophysical Characterization Of Water Solubilizing Metal Phthalocyanines For Highly Sensitive Detection In Biological Studies, Vera Tamisha Verdree

LSU Doctoral Dissertations

Efforts to improve the technology for DNA analyses stimulated the work presented here to develop a series of fluorescent probes that would aid in the increased multiplexing capabilities allowing the ability to detect multiple targets in a single measurement. Typically, spectral discrimination has been used to identify each DNA fragment in sequencing or diagnostic applications by means of unique emission properties from several labeling dyes. This has been accomplished with labels that fluoresce in the visible region. The limitations with these dyes is the broad emission profile making discrimination difficult, high intrinsic biological fluorescence and structural differences of the dyes …

Go to article

Chiral Analyses Using Molecualr Micelles And Multiple Regression Modeling In Chromatographic And Spectroscopic Methods, Alicia Williams Snearl Jan 2007

Chiral Analyses Using Molecualr Micelles And Multiple Regression Modeling In Chromatographic And Spectroscopic Methods, Alicia Williams Snearl

LSU Doctoral Dissertations

Multiple regression modeling techniques allow for rapid and accurate prediction of migration times and resolution values for micellar electrokinetic chromatography (MEKC) as well as the development of quick screening methods using steady-state fluorescence spectroscopy. All studies reported in this dissertation include optimization of calibration models and predictions of dependent variables by the use of validation samples. The root-mean-square percent relative error (RMS%RE) is used as a figure of merit for characterizing the performance of the calibration models. MEKC separations of achiral and chiral analytes were performed using an achiral molecular micelle, poly(sodium N-undecylenic sulfate), and chiral molecular micelles, poly(sodium N-undecanoyl-L-leucylvalinate) …

Go to article

The Effects Of Trawling And Habitat Use On Red Snapper And The Associated Community, Robert Joseph David Wells Jan 2007

The Effects Of Trawling And Habitat Use On Red Snapper And The Associated Community, Robert Joseph David Wells

LSU Doctoral Dissertations

The primary impediment to the recovery of Gulf of Mexico (GOM) red snapper is believed to be high levels of bycatch of age 0 and age 1 individuals in shrimp trawls. Thus, conservation of GOM red snapper involves evaluating both habitat-specific function and effects of shrimp trawls on red snapper and the associated benthic ecosystem. The two goals of this study were to evaluate the effects commercial shrimp trawls have on juvenile red snapper life history parameters, on associated fish and invertebrate communities and their habitat, and to identify essential fish habitat (EFH) for red snapper by applying all four …

Go to article

Investigation Into The Dirhodium-Catalyzed Hydroformylation Of 1-Alkenes And Preparation Of A Novel Tetraphosphine Ligand, Alexandre R. Monteil Jan 2006

Investigation Into The Dirhodium-Catalyzed Hydroformylation Of 1-Alkenes And Preparation Of A Novel Tetraphosphine Ligand, Alexandre R. Monteil

LSU Doctoral Dissertations

The reaction of the tetraphosphine ligand rac-et,ph-P4 (et,ph-P4 = PEt2CH2CH2(Ph)PCH2P(Ph)CH2CH2PEt2) with 2 equiv. of [Rh(nbd)2]+ (nbd = norbornadiene) generates [rac-Rh2(nbd)2(et,ph-P4)]2+, which is the precursor to a highly active and regioselective hydroformylation catalyst system. The “key” catalyst species generated under H2/CO pressure has been proposed to be the dihydrido complex [rac-Rh2H2(ì-CO)2(et,ph-P4)]2+, and represents one of the most dramatic example of homobimetallic …

Go to article

Effective Inter-Organizational Information And Communication Technology Adoption In Business-To-Business Customer Interface, Sanna Maria Kallioranta Jan 2006

Effective Inter-Organizational Information And Communication Technology Adoption In Business-To-Business Customer Interface, Sanna Maria Kallioranta

LSU Doctoral Dissertations

Past research has found that 80-90 percent of IT investments do not meet corporate performance objectives, primarily due to non-technical reasons such as human and organizational aspects. When Inter-organizational Information and Communication Technology (IICT) implementation is properly managed IICT can help manage the flow of goods, services, and information between business partners in the supplier-customer dyad, thus reducing transaction costs along the entire value chain. Using the underlying Resource-Based View theoretical foundation, this research approaches effective IICT implementation capability as a holistic organizational capability that extends beyond tangible IT resources. This research investigates business outcomes of IICT adoption in the …

Go to article

Simulating Protein Evolution Via Thermodynamic Models, Yanlong Xu Jan 2006

Simulating Protein Evolution Via Thermodynamic Models, Yanlong Xu

LSU Doctoral Dissertations

Natural proteins are results of evolution and they need to maintain certain thermodynamic stabilities in order to carry out their biological functions. By simulating protein evolution based on thermodynamic rules, we could reconstruct the evolution trajectory and analyze the evolutionary dynamics of a protein population, and further understand the protein sequence-structure-function relationship. In this study, we have used both a simplified lattice model and a high-resolution atomic model to simulate protein evolution processes. With the lattice model, we have investigated general theoretical questions about how protein structural designability would affect protein evolution, particularly how it would affect protein recombination and …

Go to article

Influence Of Surface Chemistry On The Aggregation Of Beta Amyloid Peptide, Mariah Joan Wooldridge Mcmasters Jan 2006

Influence Of Surface Chemistry On The Aggregation Of Beta Amyloid Peptide, Mariah Joan Wooldridge Mcmasters

LSU Doctoral Dissertations

Alzheimer's disease is a progressive neurological ailment affecting 4.5 million aging Americans. The disease is characterized by the presence in the brain of self-assembled fibrils consisting of beta amyloid protein (Aβ). Soluble Aβ protein is present in normal human cerebrospinal fluid, but it is unclear what makes the protein aggregate into insoluble plaques. There is evidence that the Aβ fibril assembly is affected by interactions with biological surfaces, such as neuronal membranes. Here, surfaces consisting of self-assembled alkanethiol monolayers with different end groups were used to test the effect of surface chemistry on the structure and morphology of aggregates formed …

Go to article

Infrared Laser Desorption/Ionization Mass Spectrometry: Fundamental And Applications, Mark Little Jan 2006

Infrared Laser Desorption/Ionization Mass Spectrometry: Fundamental And Applications, Mark Little

LSU Doctoral Dissertations

This dissertation on infrared laser desorption/ionization mass spectrometry encompasses fundamental studies of the desorption/ionization process and direct-from-gel laser desorption/ionization applications. Understanding of the fundamentals behind desorption and ionization can lead to improvements in the technique and to new applications. Experiments aimed at advancing this goal are wavelength studies and two-laser infrared/ultraviolet matrix-assisted laser desorption/ionization experiments. The direct-from-gel laser desorption/ionization application in which infrared laser desorption/ionization of analytes directly ionized after gel electrophoretic separation will also be presented. Protein and peptide standards were used as test analytes and the infrared lasers used were a 10.6 micrometers carbon-dioxide laser and a mid-IR …

Go to article

Ontology-Based Methodology For Error Detection In Software Design, Allyson M. Hoss Jan 2006

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 …

Go to article

A Computational Framework For The Structural Change Analysis Of 3d Volumes Of Microscopic Specimens, Madhusudhanan Balasubramanian Jan 2006

A Computational Framework For The Structural Change Analysis Of 3d Volumes Of Microscopic Specimens, Madhusudhanan Balasubramanian

LSU Doctoral Dissertations

Glaucoma, commonly observed with an elevation in the intraocular pressure level (IOP), is one of the leading causes of blindness. The lamina cribrosa is a mesh-like structure that provides axonal support for the optic nerves leaving the eye. The changes in the laminar structure under IOP elevations may result in the deaths of retinal ganglion cells, leading to vision degradation and loss. We have developed a comprehensive computational framework that can assist the study of structural changes in microscopic structures such as lamina cribrosa. The optical sectioning property of a confocal microscope facilitates imaging thick microscopic specimen at various depths …

Go to article

Two-Dimensional And High-Throughput Electrophoretic Separation Of Proteins Using Polymeric Microchips, Hamed Shadpour Jan 2006

Two-Dimensional And High-Throughput Electrophoretic Separation Of Proteins Using Polymeric Microchips, Hamed Shadpour

LSU Doctoral Dissertations

A major task in proteomics is to identify proteins from a biological sample using two-dimensional (2-D) separation prior to mass spectrometry of peptides generated via proteolytic digestion of the proteins. For 2-D separations, microfluidic devices are superior to bench top and capillary-based systems since they potentially provide higher separation efficiencies due to the minimal dead volumes produced during peak transfer between the two separation dimensions. In addition, fast separations can be envisioned because the column lengths are typically shorter in microfluidic platforms without scarifying peak capacity. High-throughput capabilities are extremely desirable for many types of bio-analytical analyses, such as understanding …

Go to article

Filippov's Operator And Discontinuous Differential Equations, Khalid Abdulaziz Alshammari Jan 2006

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 …

Go to article

Multianalyte Detection Of Breast Cancer By Fabrication Of Hybridmicroarrays On Polymer-Based Microanalytical Devices, Suying Wei Jan 2006

Multianalyte Detection Of Breast Cancer By Fabrication Of Hybridmicroarrays On Polymer-Based Microanalytical Devices, Suying Wei

LSU Doctoral Dissertations

Breast cancer is one of the most common and fatal cancer diseases that affect women worldwide. As is true with most other cancer diseases, early detection of breast cancer is very crucial for proper medical treatment because treatment of advanced breast cancer will be much more difficult and inconsistent. Screening and testing of breast cancer biomarkers, either genetic or proteomic, are among techniques used for diagnosis of breast cancers. Nevertheless, none of the biomarkers is by itself sensitive and selective enough for diagnosis of breast cancer, and thus, multi-analyte assays towards detection of multiple breast cancer biomarkers from different classes …

Go to article

Fabrication, Characterization And Properties Of Hiercchically Ordered Nanocomposites, Avinash Dundigalla Jan 2006

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 …

Go to article

A Community Approach To Identifying Essential Fish Habitat Of Spotted Seatrout, Cynoscion Nebulosus, In Barataria Bay, La, Pamela Sharon Dawn Macrae Jan 2006

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 …

Go to article

First Prev Next Last