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Techniques For The Optimization Of Supercritical Fluid Chromatographic Separations., Jeffrey Alan Crow

LSU Historical Dissertations and Theses

Although supercritical fluid chromatography (SFC) is now well established and still growing rapidly, it must offer clear advantages over other techniques. Thus proper method development in SFC is a necessity. There are many diverse and synergetic parameters controlling SFC separations, resulting in complex retention behavior. This work describes the proper approach to method development, including investigations into unique mobile phases and some techniques which can be used for optimization of SFC separations. In Chapter One, the concepts of chromatography with supercritical fluids are first introduced, including method development and optimization. Chapter Two focuses on mobile phase method development, and examines …

The Frost Tolerance Of Tobacco Plants Transformed With The Gene Encoding The Antifreeze Protein From Winter Flounder., Jung-Sook Lee

LSU Historical Dissertations and Theses

The winter flounder, Pseudopleuronectes americanus, can survive in sea water at temperatures below freezing by producing antifreeze-proteins (AFPs) which depress the freezing point of their cellular fluids. The antifreeze gene (IIA7 cDNA) encodes a 91 amino acid preproprotein which is processed to a mature protein of 53 amino acids. This gene encoding only the mature antifreeze-protein, including a start methionine, was cloned into a plasmid which allowed enhanced expression from a double CaMV 35S promoter. The AFP gene construct was subcloned into both the intermediate vector pMON200 and the binary vector pBI121. After triparental mating and infection of tobacco leaf …

Thermohaline And Hydrocarbon Related Diagenesis Of Lower Miocene And Upper Oligocene Sediments, West Hackberry Field, Cameron Parish, Louisiana: Implications For Mass Transport And Fluid Flow., Kathleen Mary Mcmanus

LSU Historical Dissertations and Theses

The diagenesis of Lower Miocene and Upper Oligocene sediments flanking the West Hackberry salt dome are documented in order to determine the effect the presence of salt domes may have in driving diagenetic reactions in detrital siliciclastic sediments. These sediments have undergone significant chemical diagenesis during progressive burial resulting in a reduction in porosity and permeability. Precipitation of analcime, siderite, and calcite plus the alteration of detrital volcanic lithic fragments and replacement of aluminosilicate framework grains by calcite are the dominant reactions which have altered the Upper Oligocene sands. Analcime and siderite are also present in the Oligocene mudstones. The …

Student Thought Processes And Quality Of Practice During Motor Skill Instruction., Melinda Ann Solmon

LSU Historical Dissertations and Theses

The focus of this study was the examination of relationships between initial skill level, observer estimates of attention, student thoughts, quality of practice, and achievement during motor skill instruction. Specifically, the following questions were addressed: (1) What is the relationship between observed student behavior to quality of practice and achievement? (2) What is the relationship between student reports of their cognitive processes to quality of practice and achievement? (3) Does written self-report data produce the same information as data collected during stimulated recall interviews? and (4) Are student self-report data about attention consistent with observer estimates of overt student behavior? …

Effects Of A Whole Language Approach Using Authentic French Texts On Student Comprehension And Attitude., Colette Hood Stelly

LSU Historical Dissertations and Theses

The purpose of this study was to investigate the effects of a Whole Language Approach (WLA), using authentic French stories, on measures of listening and reading comprehension of fourth-year high school students of French, and on their attitudes to learning French, as opposed to students using customary textbook materials in a conventional teacher-centered classroom setting. This investigation comprised two components: (a) a quantitative component which statistically determined results on measures of listening, reading and attitude, and, (b) a qualitative component which reviewed classroom procedures through observation and interview. Analysis of variance on four separate posttests showed statistically significant differences in …

Valuation Of Firm-Bank Relationships: A Test Of The Delegated Monitoring Hypothesis., Shane Alan Johnson

LSU Historical Dissertations and Theses

In this thesis, we test the hypothesis that banks provide monitoring services that benefit client firm shareholders. We argue that if the value of firm-bank relationships stems from monitoring services provided by banks, then share price responses associated with announcements of bank loans should be cross-sectionally related to variables that proxy the degree of monitoring to which firms are already subject. Our sample differs from previous studies of bank debt announcements in two key aspects: inclusion of NASDAQ firms, and inclusion of announcements carried by the newswire but not the Wall Street Journal. Consistent with suggestions by Fama (1985) and …

Functional Morphology Of Gustatory Centers In The Brain Of The Channel Catfish, Ictalurus Punctatus., Charles Franklin Lamb Iv

LSU Historical Dissertations and Theses

Gustatory nuclei in the isthmic region of the metencephalon and in the posterior diencephalon of the channel catfish, Ictalurus punctatus, were examined anatomically and electrophysiologically. Neurons in the superior secondary gustatory nucleus (nGS) responded to taste and tactile stimulation of large peripheral receptive fields (RFs) that often included the epithelia of the oropharyngeal cavity and whole extraoral body surface. Taste responses to amino acids and nucleotides were dose-dependent, with detected thresholds from micromolar to millimolar concentrations. The RF organization within the nGS did not display the somatotopy present in the medullary gustatory nuclei. Anatomical labeling of secondary gustatory fibers showed …

"Spades Players" And "Senators": An Ethnography Of Black Subcultures In A Community College., Anthony Louis Molina Sr

LSU Historical Dissertations and Theses

This ethnographic study of Black community college students, in a predominantly white community college, took place over a three-year period and focused on two groups. One group, the spades players, neglected their studies in favor of the card game spades, which they made the central activity of their family-like collective in the student commons. The other group, Black senators in the Student Government Association, were academic achievers who performed service to the college. By immersion into both cultures, the researcher gained the confidence of individual students in both groups, interviewed them in various settings, and looked for reasons behind the …

Efficient Data Structures And Algorithms For Scientific Computations., Soon Cheol Park

LSU Historical Dissertations and Theses

Large-scale numerically intensive scientific applications can require tremendous amounts of computer time and space. Two general methods are presented for reducing the computer resources required in scientific computing. The first is a numerical database system which is built on a space and time optimal data structure called a weighted search tree and that allows for the storage and retrieval of valuable intermediate information so costly redundant calculations can be avoided. The second is a matrix algorithm based on a new space optimal representation of sparse matrices that for typical scientific applications can be expected to dramatically decrease the cost of …

Examination Of Potato Virus X Subgenomic Rnas: Their Number, Their Coding Properties, And Their Possible Encapsidation., Mary A. Price

LSU Historical Dissertations and Theses

Potato Virus X is the type member of the Potexvirus group. It is a flexuous rod containing a single-stranded, positive-sense RNA. Previous studies have shown that during infection Potato Virus X synthesizes subgenomic RNAs to express internal cistrons. These studies demonstrated that six subgenomic RNAs could be detected in total RNA extracts from PVX-infected tissue; however, only four internal ORFs are predicted within the genomic RNA. Furthermore, two particle size populations were detected, one containing genomic RNA and one containing the coat protein mRNA. In the present investigation experiments were designed to examine PVX-encoded subgenomic RNAs with regard to their …

A Survey Of Discrepancies Among Solo Parts Of Editions And Manuscripts Of Carl Maria Von Weber's Concerto No. 1 In F Minor, Op. 73., Ronnie Everett Wray

LSU Historical Dissertations and Theses

This monograph presents a study of the interpretation of Carl Maria von Weber's Concerto No. 1 in F minor, Op. 73 for clarinet and orchestra. Twelve published editions are examined and compared with the two extant manuscript copies from the Library of Congress and the Deutsche Staatsbibliothek. Because of Weber's apparent haste or carelessness in committing music to paper, and because of certain traditions in performance, a number of attempts have been made to edit this concerto. Given the large number of editions available to the clarinetist and the varied interpretations they present, it would be difficult to determine the …

Ultrafast Measurement Of Chemical Dynamics In The Condensed Phase Using Transient Vibrational Spectroscopy., Xiaobing Xu

LSU Historical Dissertations and Theses

Geminate recombination and vibrational energy relaxation of iodine in the condensed phase are investigated using picosecond transient Raman spectroscopy. The advantages of transient Raman in measuring vibrational energy relaxation and separating different reaction dynamics are demonstrated in this dissertation. Using transient Raman spectroscopy we have for the first time directly observed geminate recombination and vibrational energy relaxation of I$\sb2$ on both X and $A\sp\prime$ $\sp3\Pi\sb{2u}$ states. For the X state, energy relaxation from vibrational levels ranging from $\upsilon$ = 52 to $\upsilon$ = 1 have been observed. These levels correspond to absolute energies of 9,300 to 210 cm$\sp{-1}$ above the …

Weak Localisation Theory For Lightly Doped Semiconductor Quantum Wires, G. Y. Hu, R. F. O'Connell

Faculty Publications

A weak localisation theory for a semiconductor quantum wire, which has a width of the order of the Fermi wavelength is presented. In the model the electronic motion is essentially one-dimensional and the localisation length L1 is much larger than the mean free path l, so that, in contrast to conventional theories a non-localised quantum wire with a total length Lproperties, the authors study the temperature dependence and the subbands effect of the weak localisation. They find that when (the phase coherent length) Lphi>L, the conductance of the quantum wire depends on L instead of Lphi, implying a temperature …

Three Essays In The Economics Of The Physician Firm, William David Bradford, Iii

LSU Historical Dissertations and Theses

This dissertation explores three aspects of the physician firm. As such, the current work is concerned with the contribution that quality considerations can make toward our understanding of the medical market. The first of three essays introduces quality into the literature aimed at estimating the supply function of physician firms. This study finds that explicit modeling of quality, both theoretically and empirically, produces results superior to past work in this field and indicates that physicians behave as if they are competitive economic agents. The second essay considers the effect of Medicaid on the behavior of physicians, especially their allocation of …

Distribution And Migration Patterns Of Subsurface Fluids In The Wilcox Group In Central Louisiana, Masaaki Funayama

LSU Historical Dissertations and Theses

Variations of pore fluid properties as well as lithologies in central Louisiana were investigated using more than 300 conventional well logs in order to understand processes and patterns of fluid flow in the Wilcox Group in the region. A statistical evaluation of log parameters was done to provide information required for interpreting older logs in the region.

Most of the study area is located between the northern and southern Louisiana salt dome basins, and there is a general lack of significant structural deformation. The two discrete sand dominated zones in the study area are the Wilcox and the post-Vicksburg groups. …

Distribution And Migration Patterns Of Subsurface Fluids In The Wilcox Group In Central Louisiana, Masaaki Funayama

LSU Historical Dissertations and Theses

Variations of pore fluid properties as well as lithologies in central Louisiana were investigated using more than 300 conventional well logs in order to understand processes and patterns of fluid flow in the Wilcox Group in the region. A statistical evaluation of log parameters was done to provide information required for interpreting older logs in the region.

Most of the study area is located between the northern and southern Louisiana salt dome basins, and there is a general lack of significant structural deformation. The two discrete sand dominated zones in the study area are the Wilcox and the post- Vicksburg …

Epicomplete Archimedean L-Groups Via A Localic Yosida Theorem, James Madden, J. Vermeer

Faculty Publications

No abstract provided.

Evolution Of The Site Of Afton Villa, Kathleen Mills Perilloux

LSU Historical Dissertations and Theses

The gardens of Afton Villa Plantation are a rare surviving example from the 1840-1860 period in Louisiana. The gardens are open to the public and are being maintained and enhanced by the present owners. The site was placed on the National Register of Historic Places in 1983. The history of the entire site of Afton Villa in West Feliciana Parish, Louisiana is discussed, tracing the historical, cultural and design influences that affected the site's development, beginning with the original settlers in the late 1700's. The house and gardens known as Afton Villa, built in 1849 by wealthy planter David Barrow …

Geology, Volcanology, And Petrology Of Cerro Bravo, A Young, Dactic, Stratovolcano In West-Central Colombia, David Tondl Lescinsky

LSU Historical Dissertations and Theses

The northernmost active Andean volcano, Cerro Bravo is a small, young, and very explosive stratovolcano. Cerro Bravo has produced voluminous tephra deposits, that are found> 30 km away, as well as, pumice flow deposits, block and ash flow deposits, and high-aspect lava flows, which are found proximally to the volcano. There have been eight episodes of activity during the past 6250±110 years (Herd, 1982), with the most recent <200 years ago and the present being a period of quiescence with no visible activity or thermal manifestations. Stratigraphic relationships suggest the occurrence of an initial explosive phase and a concluding effusive phase of activity during individual episodes. The products of volcanic activity at Cerro Bravo are a chemically and mineralogically monotonous suite of medium-K dacite and high-silica andesite (59.2- 67.5% SiO₂ pumices and lavas. The dominant phenocrysts present are plagioclase and hornblende (oxyhomblende in lavas) with lesser quantities of orthopyroxene, titanomagnetite, and rare augite and biotite also present. Petrology and eruption dynamics …

Estimation Of Primary Production Using Five Different Methods In A Spartina Alterniflora Salt Marsh, Richardus F. Kaswadji, James G. Gosselink, R. Eugene Turner

Faculty Publications

No abstract provided.

Landscape Development And Coastal Wetland Losses In The Northern Gulf Of Mexico, R. Eugene Turner

Faculty Publications

The causes of the extensive (0.86%/yr; 288,414 ha/yr) and well documented dramatic and accelerating rate of coastal wetland loss in the northern Gulf of Mexico were investigated by an interdisciplinary university research team to discern the role of outer continental shelf development. The landscape changes and potential causal agents are emphasized herein. Natural driving factors include sea level rise and geological com- paction, which appear to remain constant this century, and sediment supply from the Mississippi River which has declined by 50%,since the 1950s. Man-made influences include hydrologic changes from river diversions, flood protection levees, an extensive canal and spoil …

Wizard: A Program To Measure Cosmic-Ray Antiprotons And Positrons, And Search For Primordial Antimatter, R. L. Golden, S. P. Ahlen, J. J. Beatty, H. J. Crawford, P. J. Lindstrom, J. F. Ormes, R. E. Streitmatter, C. R. Bower, R. M. Heinz, S. Mufson, T. G. Guzik, J. P. Wefel, S. A. Stephens, J. H. Adams, K. E. Krombel, A. J. Tylka, M. Simon, K. D. Mathis, P. Picozza, G. Barbiellini, G. Basini, F. Bongiorno, M. Ricci, A. Codino, C. De Marzo, B. Managelli, P. Galeotti, P. Spillantini, M. Bocciolini

Faculty Publications

In this paper the WiZard experiment to be performed at the U.S. Space Station Freedom is presented. The apparatus will operate at the Astromag facility as a magnetic spectrometer dedicated to the search of primordial antimatter in the cosmic radiation. Several additional questions in the field of astrophysics and cosmology like solar flares, the galactic anisotropy, spectra of heavier nuclei (from carbon to iron), gamma-ray astronomy and others will also be investigated with such an apparatus and are discussed as well. The configuration of the apparatus, its integration and the description of each detector is covered in detail. Ground and …

Utilizing A Network Program Representation To Support Production System Program Development And Execution., Sally Jo Cunningham

LSU Historical Dissertations and Theses

This dissertation discusses modifications of the internal architecture of production systems that could significantly increase the execution performance of production system programs. This increased efficiency is achieved in part by modifications to the matching step of the execution cycle. Rather than checking all possible instantiations, we propose to consider only a small subset of the potential instantiations which are the "best candidates" for firing (according to the conflict resolution scheme). The increased execution efficiency provided by this matching strategy is compounded by modifying the OPS5 conflict resolution strategies. We propose a goal-directed (look-ahead) conflict resolution strategy which will still retain …

Factors Involved In Immune Modulation Of Bovine Leukemia Virus Infection., Wanda V. Pool

LSU Historical Dissertations and Theses

Bovine Leukemia Virus (BLV) is an exogenous type-C retrovirus which can induce an aleukemic (AL) stage, a persistent lymphocytotic (PL) stage, or a lymphosarcomatous (LS) stage in infected animals. After experimental infection with BLV, whole blood and serum samples were obtained from 12 holstein heifers for 103 weeks and used to correlate clinical signs (visual observation and white blood cell counts) with changes in humoral immune response (Agar gel immunodiffusion using envelope gp50 as primary antigen, and ELISA and Western immunoblots using whole BLV as antigen). Monoclonal antibodies against BLV envelope gp50 and gag p24 were produced to confirm reactivity …

Open And Closed Systems In Data Analysis Entropy., Hamid Reza Jafari

LSU Historical Dissertations and Theses

This dissertation presents an efficient and integrated approach to data analysis. Entropy data analysis is an evolution of reconstructability analysis, which investigates the relationships between parts and wholes. The central theme of the dissertation is the development of a system to condense the information in a data set into a small number of parameters. The new system is called a k-system. k-system analysis goes beyond traditional data analysis in that it has the potentiality for changes to be made to a system; and the impact of these changes can be evaluated. k-system can be useful in designing and evaluating open …

Diffusivity Estimation For Counterdiffusing Reactants In Catalytic Solids., Chauchyun Chang

LSU Historical Dissertations and Theses

The diffusivities of molecules whose sizes approach the intracrystalline pore sizes of zeolites have been studied at and near conditions prevailing during catalysis, by both desorption and kinetics techniques. For the desorption approach, a series of unary isothermal desorption experiments (following an almost instantaneous initial temperature rise) were conducted for toluene or benzene with five different zeolites. Diffusion and readsorption are shown to control the process. The intracrystalline diffusivities (D$\sb{\rm e}$) were derived by fitting the desorption curves with four models of varying complexity; only models which take into account readsorption (either at equilibrium or not) can both fit the …

Juvenile Penaeid Shrimp Ecology In A Louisiana Coastal Marsh Management Area., Everett Eric Knudsen

LSU Historical Dissertations and Theses

Juvenile penaeid shrimp were studied by a variety of methods in a southwest Louisiana, brackish marsh. Most of the work was conducted in two study ponds, one with a fixed-crest weir and the other without. In mark and recapture studies, both brown shrimp Penaeus aztecus and white shrimp P. setiferus were found to grow faster in marsh behind a fixed-crest weir. There was no apparent weir effect on mortality of either species. Brown shrimp emigrated an average of 12 d later from marsh behind the weir; white shrimp were sometimes delayed by the weir. The peak of brown shrimp emigration …

Distribution And Rate Of Methane Oxidation In Sediments Of The Florida Everglades, G. M. King, P. Roslev, H. Skovgaard

Faculty Publications

Rates of methane emission from intact cores were measured during anoxic dark and oxic light and dark incubations. Rates of methane oxidation were calculated on the basis of oxic incubations by using the anoxic emissions as an estimate of the maximum potential flux. This technique indicated that methane oxidation consumed up to 91% of the maximum potential flux in peat sediments but that oxidation was negligible in marl sediments. Oxygen microprofiles determined for intact cores were comparable to profiles measured in situ. Thus, the laboratory incubations appeared to provide a reasonable approximation of in situ activities. This was further supported …

Spectroscopy Of Hexamethyldipyrromethene Anion: Interactions With Metal Ions., Cristian Oscar Franco

LSU Historical Dissertations and Theses

This work includes: (1) a search for charge transfer interaction involving hexamethyldipyrromethene (HL) as a donor; (2) a spectroscopic study of hexamethyldipyrromethene anion (L$\sp-$), and, (3) an investigation of the spectroscopic characteristic of the copper chelate CuL$\sb2$. There are presented reactions in which HL may react with some electron acceptors. It is reported that TCNE interacts with HL to form a 1:1 complex that has an equilibrium constant of (2.5 0.9) $\times$ 10$\sp{15}$. Spectroscopic results indicate that haloacetones also interact with HL. Hexamethyldipyrromethene is a molecule that consists of two methyl substituted pyrrole rings joined by means of a vinyl …

Application Of The Fluctuating Watertable Model In The Management Of A Controlled-Drainage/Subirrigation System., Rufino Sapiton Garzon

LSU Historical Dissertations and Theses

A model was developed to predict daily change in WT depth and was used for WT management simulations. The model was calibrated and tested using climatological and WT data for a subsurface drainage system at Louisiana Agricultural Experiment Station's Ben Hur Research Farm, Baton Rouge, Louisiana. Monthly daily reaction factor and daily recharge coefficient were determined. Recharge coefficients were multiplied by a correction factor to account for antecedent soil moisture condition prior to the onset of rain. Two methods considered in the estimate of the correction factor were: Method I, the correction factor was taken as the reciprocal of the …