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

Digital Commons Network™

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

1997

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 11851 - 11880 of 12453

Full-Text Articles in Entire DC Network

The Evolution Of Landscapes And Lineages In Pitcher Plants And Their Moths., Margaret Ellen Oard Jan 1997

The Evolution Of Landscapes And Lineages In Pitcher Plants And Their Moths., Margaret Ellen Oard

LSU Historical Dissertations and Theses

Pitcher plants and pitcher plant moths exhibit two prominent themes in the long evolutionary history between plants and insects. These themes are carnivory and herbivory. In pitcher plants, the leaf has been modified into an elegant pitfall trap enabling these plants to subsist at both the producer and consumer trophic levels. Of the numerous insect species intimately associated with pitcher plants, pitcher plant moths are the only inquilines which have evolved the capacity to disrupt both the carnivore and photosynthetic functions of the host plant. The carnivorous habit, considered an adaptation for nutrient deficient environments, has contributed to species radiations …

Go to article

Synthesis And Photophysical Characterization Of Near-Ir Probes For Bioanalytical Applications., James Henry Flanagan Jr Jan 1997

Synthesis And Photophysical Characterization Of Near-Ir Probes For Bioanalytical Applications., James Henry Flanagan Jr

LSU Historical Dissertations and Theses

The research presented in this dissertation involves the synthesis and photophysical characterization of a series of tricarbocyanine dyes which can be used as fluorescent labels for bioanalytical applications. All of these dyes were synthesized to contain a heavy-atom modification to enhance k$\sb{\rm isc}$ through spin-orbit coupling and a functional group (isothiocyanate or succinimidyl ester) which is reactive towards primary amines. The spectroscopic characterization of the various chromophores was examined using absorbance and fluorescence measurements, time-correlated fluorescence, and flash photolysis. The dyes exhibit absorbance and fluorescence maxima in the near-IR (750-810 nm) with large $\varepsilon$ ($\sim$200,000 M$\sp{-1}$cm$\sp{-1})$ and $\Phi\sb{\rm f}\sim0.05$-0.15. Dyes …

Go to article

Tribological Behavior Of Duplex Nitrogen Diffusion/Dlc Coating Treatments., Yan Liu Jan 1997

Tribological Behavior Of Duplex Nitrogen Diffusion/Dlc Coating Treatments., Yan Liu

LSU Historical Dissertations and Theses

Diamond-like carbon (DLC) coatings have high potential for developing advanced tribological systems and the overall objective of the present research is to provide a framework to theoretically design and experimentally develop and study such systems of interest. The present research concentrates on the following specific aspects: the fundamental wear mechanism of DLC coatings; finite element (FE) modeling to understand the stress distribution in coating/substrate system under indentation and friction; and the influence of graded interface on the tribological behavior of DLC coatings. The experimental results showed that DLC films possess low friction coefficient ($f\sb{init}$: 0.12-0.20, $f\sb{fin}$: 0.06-0.08) and low wear …

Go to article

Activity Of Selected Insecticides Against The Soybean Looper, Pseudoplusia Includens (Walker), Using An Artificial Diet Overlay Bioassay Technique: Dosage Mortality, Discriminating Concentrations, And Resistance Monitoring., Rosanne Nicholson Mascarenhas Jan 1997

Activity Of Selected Insecticides Against The Soybean Looper, Pseudoplusia Includens (Walker), Using An Artificial Diet Overlay Bioassay Technique: Dosage Mortality, Discriminating Concentrations, And Resistance Monitoring., Rosanne Nicholson Mascarenhas

LSU Historical Dissertations and Theses

Diet overlay bioassays were conducted, evaluating insecticides requiring ingestion, on 3rd instar soybean loopers, Pseudoplusia includens (Walker). Laboratory reference and field strains were exposed to several insecticide concentrations, and LC$\sb{50}$s were compared. Field strains had significantly greater LC$\sb{50}$s than the reference strain when evaluating standard insecticides. Bioassays with experimental insecticides revealed few differences among strains. The diet overlay technique appears to be a viable method for monitoring insecticide resistance to these insecticides. Insecticide discriminating concentrations were determined using diet overlay bioassays to evaluate susceptibility of field and F1 generation, laboratory and field soybean looper strains. Field strains, exposed to permethrin …

Go to article

Phylogeny Of The Characeae (Charophyta) And Biogeography Of Chara (Characeae) Inferred From Ribosomal Rna Genes., Susan T. Meiers Jan 1997

Phylogeny Of The Characeae (Charophyta) And Biogeography Of Chara (Characeae) Inferred From Ribosomal Rna Genes., Susan T. Meiers

LSU Historical Dissertations and Theses

This dissertation examined generic, subsection, and infraspecific aspects of the phylogeny of the Characeae, and biogeography of Chara subsections and Chara haitensis. These relationships were inferred from cladistic and maximum likelihood analyses of sequence data for 18S and ITS regions of nuclear-encoded ribosomal RNA genes. Morphologically-based phylogenetic hypotheses of Wood and Imahori (1965) and Khan and Sarma (1984) concerning the six extant members of Characeae were tested. The analyses supported: monophyly of family Characeae, tribe Chareae, and of Lamprothamnium; placement of Nitellopsis basal to tribe Chareae; and an unresolved relationship between Lamprothamnium and Chara. Neither the hypothesis of Wood and …

Go to article

An Analysis Of Population Dispersal And Concentration In The United States, 1790-1990: The Frontier, Long Waves, And The Manufacturing Connection., Samuel Mark Otterstrom Jan 1997

An Analysis Of Population Dispersal And Concentration In The United States, 1790-1990: The Frontier, Long Waves, And The Manufacturing Connection., Samuel Mark Otterstrom

LSU Historical Dissertations and Theses

The United States has undergone massive changes in its population geography since 1790. A major component of these population shifts has been the rapid movement of the frontier westward. This dispersal of population through migration from relatively high densities along the eastern seaboard to the sparsely populated west was followed by concentration across most of the country after the general "closure" of the frontier. The rates of settlement growth and population concentration trends were not steady, but cyclical in nature, and they varied among the different regions of the country. This variation leads to a comparison of these phenomena with …

Go to article

Vegetation, Soils, And Hydrology Of Central Louisiana Bottomland Hardwood Forest Types., William Brown Patterson Jan 1997

Vegetation, Soils, And Hydrology Of Central Louisiana Bottomland Hardwood Forest Types., William Brown Patterson

LSU Historical Dissertations and Theses

Wetland delineation in bottomland hardwood forests is controversial due to uncertainty of the duration of inundation and soil saturation on seasonally dry sites. Wetland delineation requires an assessment of hydrophytic vegetation, hydric soils, and wetland hydrology. The objectives were to: (i) classify forest types in five Wildlife Management Areas in central Louisiana within Sharkey clay and Fausse clay soil mapping units, (ii) compare site and soil variables between the forest types, (iii) evaluate relationships between tree species distributions and soil/site factors, (iv) characterize soils in the study area, (v) evaluate differences in forest types for durations of inundation, soil saturation, …

Go to article

Determination Of Hydrocarbon Type From The Dual-Spaced Neutron Tool Responses., Luis Fernando Quintero Jan 1997

Determination Of Hydrocarbon Type From The Dual-Spaced Neutron Tool Responses., Luis Fernando Quintero

LSU Historical Dissertations and Theses

A new interpretation method that allows for the determination of the fluid type present in a formation of interest was developed. The new method is referred to as the "Three Neutron Porosity Log". The method is based on an algorithm that determines three apparent neutron porosities. These porosities, derived from the raw counts of the dual-spaced neutron tool, have three different radii of investigation. All three neutron porosities, near, far, and ratio, when properly calibrated read the true porosity in water-bearing zones. In oil or gas-bearing zones the mud filtrate invasion profile will cause the three apparent neutron porosities to …

Go to article

Development Of Diagnostic Technology For Monitoring Pyrethroid Resistance Mechanisms In The Tobacco Budworm, Heliothis Virescens (F.)., Guomin Shan Jan 1997

Development Of Diagnostic Technology For Monitoring Pyrethroid Resistance Mechanisms In The Tobacco Budworm, Heliothis Virescens (F.)., Guomin Shan

LSU Historical Dissertations and Theses

Metabolic resistance was studied in the tobacco budworm, Heliothis virescens (F.) using pyrethroid analogs, insecticide synergists, and an in vitro assay with $\sp{14}$C-cypermethrin. In initial studies, the phenoxybenzyl moiety of conventional pyrethroid, a major site of oxidative metabolism in resistant H. virescens, was replaced with P450 monooxygenase-inhibiting or oxidatively blocked groups. Isomers (1R/1S, cis/trans) of the resulting chrysanthemates were separated and tested as insecticides against pyrethroid-susceptible (LSU) and -resistant H. virescens (Pyr-R). A number of compounds with pentafluorophenyl (PFP), methylenedioxyphenyl (MDP), and propargyloxyphenyl (PP) groups were insecticidal and activity was dependent on both geometric and stereochemical configuration of the acid …

Go to article

Traffic Management And Congestion Control In The Atm Network Model., Sundararajan Vedantham Jan 1997

Traffic Management And Congestion Control In The Atm Network Model., Sundararajan Vedantham

LSU Historical Dissertations and Theses

Asynchronous Transfer Mode (ATM) networking technology has been chosen by the International Telegraph and Telephony Consultative Committee (CCITT) for use on future local as well as wide area networks to handle traffic types of a wide range. It is a cell based network architecture that resembles circuit switched networks, providing Quality of Service (QoS) guarantees not normally found on data networks. Although the specifications for the architecture have been continuously evolving, traffic congestion management techniques for ATM networks have not been very well defined yet. This thesis studies the traffic management problem in detail, provides some theoretical understanding and presents …

Go to article

The Myth Of Narcissus And The Narcissistic Structure., Joachim Conrad Hermann Vogeler Jan 1997

The Myth Of Narcissus And The Narcissistic Structure., Joachim Conrad Hermann Vogeler

LSU Historical Dissertations and Theses

Since Freud's article "On Narcissism," behavioral psychologists have predominantly viewed this phenomenon as a personality disorder. This dissertation, in contrast, provides a psychoanalytic, i.e., Lacanian reading of the myth of Narcissus as it is recorded in classical literature, and brings about an understanding of the myth's underlying structure. The four fundamental exigencies of the myth's structure include the incest prohibition which symbolically castrates the human subject, the incestuous desire as a result of this prohibition, the displacement of this desire for another imaginary object, and the obsessive quest of that image as the symptom. This structure--defined as narcissistic structure and …

Go to article

Rickettsia Felis, A Newly Discovered Rickettsia Associated With The Cat Flea (Ctenocephalides Felis Bouche)., Jimmy Wedincamp Jr Jan 1997

Rickettsia Felis, A Newly Discovered Rickettsia Associated With The Cat Flea (Ctenocephalides Felis Bouche)., Jimmy Wedincamp Jr

LSU Historical Dissertations and Theses

A study was performed to determine the life cycle of Rickettsia felis, a novel bacterium associated with cat fleas (Ctenocephalides felis Bouche). Cat flea populations maintain R. felis in successive generations by efficient transovarial transmission. Transovarial transmission was demonstrated in our study up to 12 generations. The mean infection rate for the progeny of fleas maintained on both cats and an artificial membrane system were comparable (64.3% and 58% respectively). Cats with no prior exposure to fleas were exposed to fleas infected with Rickettsia felis and monitored monthly for seroconversion via IFA. Blood samples were assayed for the presence of …

Go to article

The Polysaccharide Capsule Of Vibrio Vulnificus: Virulence, Transposon Mutagenesis, And The Identification Of An Essential Gene., Amy Buscher Zuppardo Jan 1997

The Polysaccharide Capsule Of Vibrio Vulnificus: Virulence, Transposon Mutagenesis, And The Identification Of An Essential Gene., Amy Buscher Zuppardo

LSU Historical Dissertations and Theses

The extracellular capsule polysaccharide (CPS) of Vibrio vulnificus is a primary virulence factor which allows survival of the bacteria in the human host. To study the genes involved in the production of the polysaccharide capsule, 23 mutants were generated that lost their ability to produce CPS due to the insertion of a mini-transposon into the genome of the encapsulated clinical strain V. vulnificus 1003 (O). The mutants were examined by Southern blot analysis to ensure the transposon had inserted only once in the chromosome. Exoenzymes, which are believed to contribute to the virulence of the organism, produced by all 23 …

Go to article

The Compliance-Seeking Process From The Perspective Of The Respondent: The Role Of Goals In Responses To Requests., Barbara L. Woods Jan 1997

The Compliance-Seeking Process From The Perspective Of The Respondent: The Role Of Goals In Responses To Requests., Barbara L. Woods

LSU Historical Dissertations and Theses

This study examined compliance seeking from the perspective of recipients of direct requests with respect to types of responses, goals, liking, and locus of control. A total of 211 employed adults completed a survey that included responses to hypothetical request scenarios involving liked and disliked co-workers, measures of goals factors, and a measure of locus of control. Six types of responses were identified: simple agreement, elaborated agreement, simple refusal, refusal with reasons, request more information, and postpone decision. Participants reported a tendency to agree with requests, regardless of liking. Factor analyses revealed three-factor models for the liked and disliked conditions. …

Go to article

The Effects Of Hypoestrogenism On Rest And Acute Submaximal Exercise Metabolism Using A Gnrh Agonist Analogue Model., Sheri Anne Melton Jan 1997

The Effects Of Hypoestrogenism On Rest And Acute Submaximal Exercise Metabolism Using A Gnrh Agonist Analogue Model., Sheri Anne Melton

LSU Historical Dissertations and Theses

During menopause, many women experience weight gain which is mostly in the form of abdominal and upper body fat deposition. This phenomenon has been recognized as an independent predictor of cardiovascular disease in females. Other disease processes, such as diabetes, hypertension and some cancers, specifically, breast and esophageal have been linked to obesity. Thus, the occurrence of increased body fat is placing the postmenopausal female in jeopardy of a potential life-threatening position. The connection between the lack of estrogen seen in menopause and weight gain remains unclear, but studies have shown that estrogen status may affect carbohydrate and fat metabolism. …

Go to article

A Search For Biologically Active Phytochemicals From Endemic Plants Of The Southeastern United States., Steven Lynn Robbs Jan 1997

A Search For Biologically Active Phytochemicals From Endemic Plants Of The Southeastern United States., Steven Lynn Robbs

LSU Historical Dissertations and Theses

In an investigation of allelopathy in the Florida scrub, bioassays with terpenes were performed against: Lactuca sativa, Rudbeckia hirta, Leptochloa dubia and Schizachyrium scoparium. Cineole was phytotoxic against Rudbeckia at 17 ppm and Lactuca at 165 ppm. (S)-camphor was phytotoxic to Rudbeckia at 1 ppm, Lactuca at 28 ppm, and Leptochloa and Schizachyrium at 134 ppm. (R)-Camphor, myrtenol and myrtenal were phytotoxic against Rudbeckia at concentrations of 28, 25 and 15 ppm respectively. Farnesol stimulated the germination of Schizachyrium at concentrations up to 50 ppm and at 100 ppm it reduced the radicle length of all test species. Geraniol stimulated …

Go to article

Efficient Mapping Of Neural Network Models On A Class Of Parallel Architectures., Behnam Seyed Arad Jan 1997

Efficient Mapping Of Neural Network Models On A Class Of Parallel Architectures., Behnam Seyed Arad

LSU Historical Dissertations and Theses

This dissertation develops a formal and systematic methodology for efficient mapping of several contemporary artificial neural network (ANN) models on k-ary n-cube parallel architectures (KNC's). We apply the general mapping to several important ANN models including feedforward ANN's trained with backpropagation algorithm, radial basis function networks, cascade correlation learning, and adaptive resonance theory networks. Our approach utilizes a parallel task graph representing concurrent operations of the ANN model during training. The mapping of the ANN is performed in two steps. First, the parallel task graph of the ANN is mapped to a virtual KNC of compatible dimensionality. This involves decomposing …

Go to article

Cost Analysis And Air Pollution Impact Of Electric Vehicles On A Metropolitan Area., Hector David Arias-Varela Jan 1997

Cost Analysis And Air Pollution Impact Of Electric Vehicles On A Metropolitan Area., Hector David Arias-Varela

LSU Historical Dissertations and Theses

During the 1990's, increasing attention has been paid to electric vehicles (EV's) because of their potential to reduce air pollution in metropolitan areas such as the Los Angeles Metropolitan Area in the U.S., Mexico City and Its Metropolitan Area in Mexico, Greater London in the United Kingdom and other urban areas. However, few studies to determine the costs and benefits of reducing air pollution by introducing EV's into these mega cities have been carried out. A model to determine the marginal costs and environmental impact of electric vehicles on a metropolitan area is designed in this study. The model simulates …

Go to article

Electron Scattering Studies In The Framework Of The Symplectic Shell Model., Jutta Escher Jan 1997

Electron Scattering Studies In The Framework Of The Symplectic Shell Model., Jutta Escher

LSU Historical Dissertations and Theses

Electron scattering offers numerous advantages for studying nuclear structure: the weakness of the electromagnetic interaction, the precise knowledge of the reaction mechanism, the ability to vary independently the transferred momentum and energy, as well as the excellent spatial resolution that can be obtained with the point-like probing particles, have made this approach a valuable tool in nuclear physics. Scattering experiments provide crucial tests for the applicability and limitations of modern nuclear models and further our understanding of the nucleon-nucleon interaction and its modifications in nuclear matter. A microscopic theory for deformed nuclei, which takes proper account of the Exclusion Principle …

Go to article

The Effects Of Augmented Feedback On Students' Perceptions And Performance., Karen Anne Buckner Fredenburg Jan 1997

The Effects Of Augmented Feedback On Students' Perceptions And Performance., Karen Anne Buckner Fredenburg

LSU Historical Dissertations and Theses

The focus of this study was to investigate the effects of various augmented feedback conditions on students' self-perceptions of ability (SPA), practice behaviors, and performance during motor skill instruction of a novel task. Fourth grade physical education students (n = 103) participating in a one week instructional unit on the skill of cupstacking were randomly assigned to one of four feedback conditions: (a) no feedback, (b) motivational feedback, (c) task or informational feedback, and (d) motivational and task feedback combined. While students practiced simple (3 x 6 x 3) and complex (1 x 10 x 1) cupstacking skills, instruction and …

Go to article

Interactive Effects Of Weeds And Defoliating Insects In Soybean (Glycine Max)., Charles Frost Grymes Jan 1997

Interactive Effects Of Weeds And Defoliating Insects In Soybean (Glycine Max)., Charles Frost Grymes

LSU Historical Dissertations and Theses

Field experiments were conducted to evaluate the influence of simulated insect defoliation and full season weed competition on soybean (Glycine max (L.) Merr.) growth and yield. Weeds were johnsongrass (Sorghum halepense (L.) Pers.), common cocklebur (Xanthium strumarium L.), and hemp sesbania (Sesbania exaltata (Raf.) Rybd. ex A. W. Hill) at 15, 3, and 12 plants/6 m of row. Simulated defoliation at R2 and R5 soybean growth stages was accomplished by removal of 0, 1, or 2 leaflets per soybean trifoliate, which approximated 0, 33, and 66% defoliation, respectively. Averaged across defoliation levels and stages, johnsongrass, common cocklebur, and hemp sesbania …

Go to article

I. Photophysics And Photochemistry Of Molybdenum-Oxo Complexes. Ii. Synthesis Of A Ferrocene-Based Monomer For Use In Ring-Opening Metathesis Polymerization., Ralph Isovitsch Jan 1997

I. Photophysics And Photochemistry Of Molybdenum-Oxo Complexes. Ii. Synthesis Of A Ferrocene-Based Monomer For Use In Ring-Opening Metathesis Polymerization., Ralph Isovitsch

LSU Historical Dissertations and Theses

The brick-red ferrocenophene 1,4-(3,3$\sp\prime$-bis(1,1-dimethylpentyl)-1,1$\sp\prime$-ferrocenediyl) -1,3-butadiene was prepared via a six-step synthetic route. It was isolated and characterized for use as a monomer in Ring Opening Metathesis Polymerization. Fluorescent molybdenum(V)-oxo complexes such as $\rm MoOCl\sb4(H\sb2O)\sp-$ undergo thermal and photochemical reactions with the series of phosphines $\rm PEt\sb2,\ PEt\sb3Ph,\ PEtPh\sb2$ and PPh$\sb3$ as oxygen atom acceptors. PEt$\sb3$ reacts spontaneously to form several products: $\rm (PPh\sb4)\lbrack MoCl\sb4(PEt\sb3)\sb2\rbrack,\ (PPh\sb4)\sb2\lbrack MoOCl\sb5\rbrack{\cdot}2CH\sb2Cl\sb2,$ and a maroon oil that contains $\rm OPEt\sb3,\ MoOCl\sb2(PEt\sb3)\sb3$ and $\rm MoCl\sb4(PEt\sb3)\sb2.$ Both $\rm (PPh\sb4)\lbrack MoCl\sb4(PEt\sb3)\sb2\rbrack$ and OPEt$\sb3$ are products of an oxygen atom transfer reaction. PEt$\sb2$Ph and PEtPh$\sb2$ also produce the corresponding phosphine …

Go to article

Applying Significance Testing To The Taguchi Methods Of Quality Control., Shannon Jo Kast Jan 1997

Applying Significance Testing To The Taguchi Methods Of Quality Control., Shannon Jo Kast

LSU Historical Dissertations and Theses

During recent years, the Taguchi Methods of quality control have been adopted in many industries because the goal of the methods is to produce a product or process that is robust to environmental conditions and component variation. The methodology involves using statistical experimental designs to achieve this goal through analyzing a performance measure, called a signal-to-noise ratio, that takes into account both variation and target value. However, many statisticians have criticized the Taguchi Methods for the lack of use of sound statistical practices. This research will focus on one specific aspect of the Taguchi Methods: the signal-to-noise ratio. Sampling distributions …

Go to article

An Investigation Of The Motives In Going-Private Transactions: The Case Of Re-Lbos., Arman Kosedag Jan 1997

An Investigation Of The Motives In Going-Private Transactions: The Case Of Re-Lbos., Arman Kosedag

LSU Historical Dissertations and Theses

The commonly understood and traditional forms of termination for a public firm are the takeover and bankruptcy. "Going private" is a new and interesting third alternative. Once the "going public" option--a significant number of observed reverse leveraged buyout (LBO) cases--is taken into account, however, the fundamental difference between this new alternative and traditional ways becomes apparent. Even more fascinating than the "public-to-private private-to-public" move is the fact that some companies go private again. This dissertation examines the phenomenon of re-LBOs; that is, the practice of going private via management buyout, then reobtaining public status through a new initial public offering, …

Go to article

Errand Into The Wilderness And America: An Analysis Of The Effects Of Puritan Symbols On The Perceived Purpose Of Education In America., E. Douglas Mcknight Jan 1997

Errand Into The Wilderness And America: An Analysis Of The Effects Of Puritan Symbols On The Perceived Purpose Of Education In America., E. Douglas Mcknight

LSU Historical Dissertations and Theses

Present day America is perceived as immersed in a moral crisis due to certain cultural conditions; that national identity has fractured, resulting in a pervading sense of uncertainty and anxiety about the future; that public schools, as institutions charged with preserving the symbols of national identity and a morality that is the concrete expression of those symbols, have failed and must be reformed; and finally, that only through "schooling" can America be saved from this current cultural crisis. This rhetorical trajectory has a history that extends back to the Puritans who settled in America during the early seventeenth century and …

Go to article

Stabilization And Ionization Suppression In Intense Pulsed Fields., Vijay Saradhi Poduri Jan 1997

Stabilization And Ionization Suppression In Intense Pulsed Fields., Vijay Saradhi Poduri

LSU Historical Dissertations and Theses

The phenomenon of stabilization and ionization suppression in intense pulsed fields is investigated for systems initially in their ground states. This is done by considering one-dimensional model potentials which include one bound state and many bound states. The phenomenon of intense field stabilization is found to exist for both types of potentials while the pulse is on. However, it is discovered that this is not accompanied by suppression of ionization at the end of the pulse in all regimes of the peak field strength. The main features of the variation of the ionization probability with the peak field strength are: …

Go to article

Americans And German Youth In Nuremberg, 1945-1956: A Study In Politics And Culture., Harald Thomas Oskar Leder Jan 1997

Americans And German Youth In Nuremberg, 1945-1956: A Study In Politics And Culture., Harald Thomas Oskar Leder

LSU Historical Dissertations and Theses

While American policy makers needed three years after World War II to recognize the importance of re-educating German youth and to develop a consistent policy, a look at Nuremberg reveals that American representatives in the field started positive and constructive programs immediately after the war. American soldiers ignored non-fraternization, the Army became heavily involved in helping German communities survive, while the Youth Section of the Office of Military Government was the first to focus on persuasion instead of coercion in its re-education efforts. It designed long range programs to introduce young Germans to a democratic culture. Official American policy simply …

Go to article

Seafloor Morphology, Geologic Framework, And Sedimentary Processes Of A Sand-Rich Shelf Offshore Alabama And Northwest Florida: Northeastern Gulf Of Mexico., Randolph Alexander Mcbride Jan 1997

Seafloor Morphology, Geologic Framework, And Sedimentary Processes Of A Sand-Rich Shelf Offshore Alabama And Northwest Florida: Northeastern Gulf Of Mexico., Randolph Alexander Mcbride

LSU Historical Dissertations and Theses

Late-Pleistocene and Holocene geology of the northeastern Gulf of Mexico shelf offshore Alabama and northwest Florida was investigated using 38 vibracores, 47 radiocarbon dates, foraminiferal and macrofauna assemblages, and bathymetry data. The morphologic and stratigraphic signatures of the last rise of eustatic sea level was examined along a passive continental margin. Major shelf features include shore-oblique sand ridges, mid-shelf linear shoals, and shelf-edge deltas. Surficial shelf sediments consist of $>$90% sand, $<$2.7% mud, and $<$2% granules and fine in a westerly direction from a medium to fine sand. The sharp boundary that demarcates these two sand types (Apalachicola and Mobile subprovinces) was identified for the first time in this study. Six facies and two erosional surfaces characterize shelf stratigraphy. Facies 1 is a Pleistocene soil horizon. This facies is truncated by a major erosional unconformity (Type 1 sequence boundary) created by subaerial exposure during the last sea level lowstand and the bay ravinement process during the ensuing transgression. Fine-grained estuarine deposits (Facies 2, 3, or 4 (lower transgressive systems tract)) overlie the unconformity. Facies 3 and 4 are truncated by a shoreface ravinement diastem (flooding surface) and overlain by a marine shell-bed (Facies 5; lower shoreface). Facies 5 grades into Facies 6, a quartz sand with marine foraminifera. Facies 5 and 6 comprise the upper transgressive systems tract (up to 5.5 m thick). Compared to a eustatic sea level curve, mollusk dates from estuarine shell beds show a time-transgressive trend, whereas marine shell beds are time-averaged. Transgressive and post-transgressive processes (strong cold fronts, tropical cyclones) concentrate marine mollusks above the shoreface ravinement diastem. Consequently, linear shoals are not in-situ or degraded barriers because marine species dominate the foraminiferal and molluscan assemblages, and deposits lie above shoreface ravinement diastem. Although shelf morphology is similar to modern barrier island geomorphology, shelf morphostratigraphy (linear shoals) is related to transgressive and post-transgressive processes. Shoal form and orientation are dictated by underlying transgressive topography (escarpments) that was cut into the Pleistocene substrate during the Holocene transgression. During transgression, erosional shoreface retreat produced a trailing sand sheet that draped the transgressive topography.

Go to article

Reduction And Management Of Risks Associated With Aflatoxin And Fumonisin Contamination In Corn., Socrates Trujillo Jan 1997

Reduction And Management Of Risks Associated With Aflatoxin And Fumonisin Contamination In Corn., Socrates Trujillo

LSU Historical Dissertations and Theses

Aflatoxins and fumonisins, secondary mold metabolites, occur naturally as co-contaminants in corn. Health and economic risks associated with this contamination of food and feed have been the focus of much research worldwide. Research programs resulting from the discovery of aflatoxins in the 1960's has been used to guide study programs for fumonisins. The establishment of food safety programs, including mycotoxin decontamination procedures, must be evaluated for further application. The evaluation of selected procedures which reduce the risks associated with the contamination of these mycotoxins in food utilized for human and animal consumption was the focus of this study. This study …

Go to article

Nanoscale Structures And Fracture Processes In Advanced Ceramics: Million-Atom Md Simulations On Parallel Architectures., Andrey A. Omeltchenko Jan 1997

Nanoscale Structures And Fracture Processes In Advanced Ceramics: Million-Atom Md Simulations On Parallel Architectures., Andrey A. Omeltchenko

LSU Historical Dissertations and Theses

Properties and processes in silicon nitride and graphite are investigated using molecular-dynamics (MD) simulations. Scalable and portable multiresolution algorithms are developed and implemented on parallel architectures to simulate systems containing 10$\sp6$ atoms interacting via realistic potentials. Structural correlations, mechanical properties, and thermal transport are studied in microporous silicon nitride as a function of density. The formation of pores is observed when the density is reduced to 2.6 g/cc, and the percolation occurs at a density of 2.0 g/cc. The density variation of the thermal conductivity and the Young's modulus are well described by power laws with scaling exponents of 1.5 …

Go to article

First Prev Next Last