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Articles 2341 - 2370 of 3417

Full-Text Articles in Physical Sciences and Mathematics

Exploration Of Ternary Intermetallic Materials Using Tin And Gallium Flux, Edem Kodzo Okudzeto Jan 2009

Exploration Of Ternary Intermetallic Materials Using Tin And Gallium Flux, Edem Kodzo Okudzeto

LSU Doctoral Dissertations

The focus of this dissertation is the structure-property relationships of ternary intermetallic stannides and gallides. We are interested in these compounds because of the wide range of physical properties they possess. While investigating the Ln-Co-Sn system (Ln = lanthanide), we have synthesized single crystals that crystallize in the Yb3Rh4Sn13, Ho7Co6Sn23 and the Tb5Rh6Sn18 structure types. We observe the formation of a particular structure type depending on the size of the lanthanide present. The aforementioned compounds all contain CoSn6 trigonal prisms, which create voids occupied by Ln and Sn polyhedral units. We have also investigated the physical properties of these compounds …

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The Structure Of 4-Separations In 4-Connected Matroids, Jeremy M. Aikin Jan 2009

The Structure Of 4-Separations In 4-Connected Matroids, Jeremy M. Aikin

LSU Doctoral Dissertations

Oxley, Semple and Whittle described a tree decomposition for a 3-connected matroid M that displays, up to a natural equivalence, all non-trivial 3-separations of M. Crossing 3-separations gave rise to fundamental structures known as flowers. In this dissertation, we define generalized flower structure called a k-flower, with no assumptions on the connectivity of M. We completely classify k-flowers in terms of the local connectivity between pairs of petals. Specializing to the case of 4-connected matroids, we give a new notion of equivalence of 4-separations that we show will be needed to describe a tree decomposition for 4-connected matroids. Finally, we …

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Atom-Based Computer Simulation Studies Of Gas-To-Liquid Nucleation In Atmospherically Relevant Systems: Clarifying Discrepancies And Elucidating Mechanisms, Ricky Bendanillo Nellas Jan 2009

Atom-Based Computer Simulation Studies Of Gas-To-Liquid Nucleation In Atmospherically Relevant Systems: Clarifying Discrepancies And Elucidating Mechanisms, Ricky Bendanillo Nellas

LSU Doctoral Dissertations

For over a century, nucleation for all systems was thought simplistically to be a process that advances through the formation of critical clusters with a well-defined composition. Our results show intriguing nucleation mechanisms that challenge the aforementioned notion. We employed the simple TraPPE-UA (transferable potential for phase equilibria – united atom) force field and the AVUS-HR approach (a combination of aggregation-volume-bias Monte Carlo, umbrella sampling, and histogram reweighting), to investigate the homogeneous vapor-to-liquid nucleation of various nucleating systems. We found out that these systems could nucleate through a variety of unique non-ideal mechanisms. Alongside existing experimental investigations, this dissertation presents …

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Fabrication Of Nanostructured Surfaces With Well-Defined Chemistry Using Particle Lithography, Jie-Ren Li Jan 2009

Fabrication Of Nanostructured Surfaces With Well-Defined Chemistry Using Particle Lithography, Jie-Ren Li

LSU Doctoral Dissertations

Natural self-assembly processes provide nanofabrication capabilities for designing surfaces with nanoscale control of surface chemistry and relative orientation of the nanomaterials on the surfaces. Particle lithography was used to produce periodic arrays of protein nanostructures. Monodisperse mesoparticles can be applied to rapidly prepare millions of uniform protein nanostructures on flat surfaces using the conventional benchtop chemistry steps of mixing, centrifuging, evaporation and drying. Nanopatterns of bovine serum albumin and staphylococcal protein A were produced with particle lithography. The immobilized proteins remain attached to the surface and form nanopatterns over micron areas corresponding to the thickness of a single layer of …

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A Modular Approach To Lung Nodule Detection From Computed Tomography Images Using Artificial Neural Networks And Content Based Image Representation, Omer Muhammet Soysal Jan 2009

A Modular Approach To Lung Nodule Detection From Computed Tomography Images Using Artificial Neural Networks And Content Based Image Representation, Omer Muhammet Soysal

LSU Doctoral Dissertations

Lung cancer is one of the most lethal cancer types. Research in computer aided detection (CAD) and diagnosis for lung cancer aims at providing effective tools to assist physicians in cancer diagnosis and treatment to save lives. In this dissertation, we focus on developing a CAD framework for automated lung cancer nodule detection from 3D lung computed tomography (CT) images. Nodule detection is a challenging task that no machine intelligence can surpass human capability to date. In contrast, human recognition power is limited by vision capacity and may suffer from work overload and fatigue, whereas automated nodule detection systems can …

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Beta-Diketone And -Ketoenamine-Based Organic Building Blocks For Porous Metal Organic-Materials, Yoseph Solomon Marcos Jan 2009

Beta-Diketone And -Ketoenamine-Based Organic Building Blocks For Porous Metal Organic-Materials, Yoseph Solomon Marcos

LSU Doctoral Dissertations

This dissertation focuses on synthesis of multifunctional â-diketone and â-ketoenamine ligands and their reaction with metal ions, mainly Cu2+. Several new bi-, tri-, and tetrafunctional organosilicon â-diketone building blocks with â-diketone groups at approx. 109° (tetrahedral) were successfully synthesized. New thiophene based bifunctional ligands where the â-diketones are at about 145° are also reported here. We also prepared a range of new aryl-â-ketoenamines from their analogous â-diketones in very high yield using a simple microwave-assisted procedure. Reactions of organosilicon tris(â-diketone)s LH3 with Cu2+ were explored quite intensively. These ligands form metal-organic-polyhedra (MOPs) that are soluble in organic solvents, and insoluble …

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Spatial-Temporal Responses Of Louisiana Forests To Climate Change And Hurricane Disturbance, Fugui Wang Jan 2009

Spatial-Temporal Responses Of Louisiana Forests To Climate Change And Hurricane Disturbance, Fugui Wang

LSU Doctoral Dissertations

This dissertation research focused on three questions: (1) what is the current carbon stock in Louisiana’s forest ecosystems? (2) how will the biomass carbon stock respond to future climate change? and (3) how vulnerable are the coastal forest resources to natural disturbances, such as hurricanes? The research utilized a geographic information system, remote sensing techniques, ecosystem modeling, and statistical approaches with existing data and in-situ measurements. Future climate changes were adapted from predictions by the Community Climate System Model on the basis of low (B1), moderate (A1B), and high (A2) greenhouse gas emission scenarios. The study on forest carbon assessment …

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Multiple Dataset Visualization (Mdv) Framework For Scalar Volume Data, Gaurav Khanduja Jan 2009

Multiple Dataset Visualization (Mdv) Framework For Scalar Volume Data, Gaurav Khanduja

LSU Doctoral Dissertations

Many applications require comparative analysis of multiple datasets representing different samples, conditions, time instants, or views in order to develop a better understanding of the scientific problem/system under consideration. One effective approach for such analysis is visualization of the data. In this PhD thesis, we propose an innovative multiple dataset visualization (MDV) approach in which two or more datasets of a given type are rendered concurrently in the same visualization. MDV is an important concept for the cases where it is not possible to make an inference based on one dataset, and comparisons between many datasets are required to reveal …

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A Study Of The Self-Assembly Of Water-Soluble Porphyrins In Aqueous Solution, Javoris Hollingsworth Jan 2009

A Study Of The Self-Assembly Of Water-Soluble Porphyrins In Aqueous Solution, Javoris Hollingsworth

LSU Master's Theses

In nature, self-assembly processes of biologically active organic molecules often occur, resulting in formation of dimers and higher oligomers of various and sometimes complex structures. This natural occurrence of self-organization has been the subject of research, with the aim of understanding and possibly modulating the aggregation behavior of biological molecules. The meso-tetrakis(4-phosphonatophenyl) porphyrin, H2TPPP was synthesized, purified, and characterized. Its self-assembly was studied in aqueous solutions as a function of pH and time. The variations on the λmax and shape of the Soret band of this porphyrin in the absorption spectra when altering the pH indicated the pH dependency in …

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Translocation Success Of Adult Red-Cockaded Woodpeckers, Erin Herbez Jan 2009

Translocation Success Of Adult Red-Cockaded Woodpeckers, Erin Herbez

LSU Master's Theses

The red-cockaded woodpecker (Picoides borealis; hereafter RCW) is a cooperative breeder endemic to open old-growth pine savannah ecosystems in the southeastern United States (Jackson 1994). The RCW was listed as federally endangered in 1973, after a population decline due to habitat loss. Habitat fragmentation produces isolated populations of RCWs, which in turn ultimately limits the success of the species. RCW biologists and managers counteract effects of fragmentation by aggregating recruitment clusters and translocation. Although several studies examined subadult RCW translocation, detailed studies examining adult translocation have been limited. My study was conducted on a 3500 ha area owned by Plum …

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Characterization And Transitions Of Asphalt Cement Composite Materials, Brent Harper Sellers Jan 2009

Characterization And Transitions Of Asphalt Cement Composite Materials, Brent Harper Sellers

LSU Master's Theses

Blends of a PG 64-22 asphalt with a range of load levels (0.2 — 20 wt %) of Sasobit® wax and a single loading of 2 wt % Elvaloy AM® were prepared and characterized. Sasobit® wax is a high molecular weight paraffinic wax produced commercially through the Fischer-Tropsch process. Elvaloy AM® is a reactive elastic terpolymer, comprised of ethylene, butyl acrylate and glycidyl methacrylate monomeric units. The blends were analyzed by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), x-ray diffraction, epifluorescence microscopy, scanning laser confocal microscopy, and dynamic shear rheology. Sasobit (1 wt %) composite material showed little difference …

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Holocene Evolution And Avulsion History Of The Lower Mississippi River, Yazoo Basin, Ms, Eric Prokocki Jan 2009

Holocene Evolution And Avulsion History Of The Lower Mississippi River, Yazoo Basin, Ms, Eric Prokocki

LSU Master's Theses

Optically stimulated luminescence dates coupled with paleohydrological estimations from lower Mississippi River (LMR) meander belts within the Yazoo Basin, MS provide new insight into the geochronological and hydrologic history of the LMR throughout the Holocene period. According to OSL dates, there are only three temporally equivalent LMR meandering river regime sediment packages, and not five as previously assumed from past geochronological research initiatives within the lower Mississippi Valley (LMV). The three geochronological sediment packages from oldest to youngest are thus represented by the following LMR meander belts: Early Holocene Chronostratigraphic Package – ca. 9.19 to 8.07 ka represented by the …

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Historic Sediment Accretion Rates In A Louisiana Coastal Marsh And Implications For Sustainability, Rebekah Perkins Smith Jan 2009

Historic Sediment Accretion Rates In A Louisiana Coastal Marsh And Implications For Sustainability, Rebekah Perkins Smith

LSU Master's Theses

Deltaic marshes of the Mississippi River in Louisiana disappeared at a rate of 88 km2 annually from 1956 to 2000 (Barras et al. 2003) as marshes become inundated by sea water. Marsh surface elevation varies spatially and temporally due to fluvial sediment deposition, resuspension, erosion, compaction, sea level rise, and organic matter accumulation and decomposition. If net accretion from sediment deposition and/or peat production is insufficient, marshes respond to sea level rise by migrating landward. Since human development prevents landward migration of marsh in Breton Sound Basin, Louisiana, marsh sustainability can only be achieved if vertical accretion keeps pace with …

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Platforms And Protocols For The Multidimensional Microchip Electrophoretic Analysis Of Complex Proteomes, John K. Osiri Jan 2009

Platforms And Protocols For The Multidimensional Microchip Electrophoretic Analysis Of Complex Proteomes, John K. Osiri

LSU Doctoral Dissertations

The need for rapid, portable and high-throughput systems in proteomics is now prevalent because of demands for generating new protein-based disease biomarkers. However, 2-D protein profile patterns are lending themselves as potential diagnostic tools for biomarker discovery. It is difficult to identify protein biomarkers which are low abundant in the presence of highly abundant proteins, especially in complex biological samples like serum. Protein profiles from 2-D separation of the protein content of cells or body fluids, which are unique to certain physiological or pathological states, are currently available on internet databases. In this work, we demonstrate the ability to separate …

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Experimental Design, Synthesis And Application Of Molecular Micelle Modified Polymeric Nanoparticles For Drug Delivery Systems And Free Radical Detection, Gabriela M. Ganea Visser Jan 2009

Experimental Design, Synthesis And Application Of Molecular Micelle Modified Polymeric Nanoparticles For Drug Delivery Systems And Free Radical Detection, Gabriela M. Ganea Visser

LSU Doctoral Dissertations

Biodegradable and biocompatible polymeric nanoparticles such as poly (lactide-co-glycolide) (PLGA) nanoparticles have been extensively studied as drug delivery systems for a variety of pharmaceutical agents. Nanoparticle surface properties are primarily determined by the emulsifiers used in the synthesis process, which have a significant impact on nanoparticle physico-chemical and biological properties. Anionic amino acid – based molecular micelles were used in the emulsification process to prepare monodisperse, small (below 100 nm) PLGA nanoparticles with a well defined spherical shape. Such molecular micelle – modified nanoparticles were used as drug carriers for delivery of antioxidants. Thymoquinone is a natural antioxidant, and an …

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Modeling Gag Grouper (Mycteroperca Microlepis) In The Gulf Of Mexico: Exploring The Impact Of Marine Reserves On The Population Dynamics Of A Protogynous Grouper, Robert D. Ellis Jan 2009

Modeling Gag Grouper (Mycteroperca Microlepis) In The Gulf Of Mexico: Exploring The Impact Of Marine Reserves On The Population Dynamics Of A Protogynous Grouper, Robert D. Ellis

LSU Master's Theses

The gag grouper (Mycteroperca microlepis) population in the Gulf of Mexico supports both a commercial and recreational fishery but has experienced a decrease in the male to female sex ratio over the past thirty years. Protogynous fish populations naturally have a smaller male to female ratio than gonochoristic fish populations; however the decline in the gag population is such that sperm limitation may be occurring. In an effort to correct the decline in sex ratio, fishery managers have recently implemented two marine reserves designed specifically to protect gag spawning aggregations. Results from two population models (an age-structured model and an …

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Anthropogenic And Natural Perturbations On Lower Barataria Bay, Louisiana: Detecting Responses Of Marsh-Edge Fishes And Decapod Crustaceans, Agatha-Marie Fuller Roth Jan 2009

Anthropogenic And Natural Perturbations On Lower Barataria Bay, Louisiana: Detecting Responses Of Marsh-Edge Fishes And Decapod Crustaceans, Agatha-Marie Fuller Roth

LSU Doctoral Dissertations

Barataria Bay, Louisiana is a dynamic estuary with ongoing disturbances that is in need of restoration. Development and validation of a lower Barataria Bay index of biotic integrity (IBI) for the summer season was the focus of my research. This IBI was created using 2005 data and evaluated with 2006 and 2007 data to demonstrate the feasibility of this approach in coastal Louisiana. The IBI successfully distinguished sites with differing levels of degradation using nine fish metrics. While pursuing this effort, two serendipitous events occurred when an oil spill then a hurricane impacted the study area. This gave me opportunities …

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Achiral, Chiral, And Protein Separations With Molecular Micelles Using Chromatographic Techniques, Candace Ayanna Luces Jan 2009

Achiral, Chiral, And Protein Separations With Molecular Micelles Using Chromatographic Techniques, Candace Ayanna Luces

LSU Doctoral Dissertations

In this dissertation, several chromatographic techniques were developed for separation of proteins as well as achiral and chiral compounds. Firstly, polyelectrolyte multilayer (PEM) coatings were used to separate chiral analytes and proteins of pharmaceutical and biomedical interests. Coating polymers used in PEM coatings are instrumental in analyte separation. Therefore, the effect of changing four different cationic polymers, (poly-L-lysine, poly-L-ornithine, poly-L-lysine-serine, and poly-L-glutamic acid-lysine) and three anionic polymers (sodium poly (N-undecanoyl-L-leucyl-alaninate) (poly-L-SULA), sodium poly (N-undecanoyl-L-leucyl-valinate) (poly-L-SULV) and sodium poly (undecylenic sulfate) (poly-SUS)) were investigated. The simultaneous effects of cationic polymer concentration, number of bilayers, temperature, applied voltage, and pH of the …

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The Extended Picture Group, With Applications To Line Arrangement Complements, Charles Richard Egedy Jan 2009

The Extended Picture Group, With Applications To Line Arrangement Complements, Charles Richard Egedy

LSU Doctoral Dissertations

We obtain the picture group as the quotient with a torsion subgroup, of an extended picture group, which is isomorphic to the kernel of a precrossed module homomorphism. In addition to expanding the notion of a picture group, the new formulation gives a natural way to construct homomorphisms between picture groups by describing deformations of one-vertex subpictures. The extended picture group thus provides a convenient way to describe generators for the second homotopy group of line arrangement complements as well as homomorphisms between these groups. In particular, we show that the homomorphisms relate to a lattice structure corresponding roughly to …

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Life History Characteristics Of Alligator Gar, Atractosteus Spatual, In The Bayou Dularge Area Of Southcentral Louisiana, Kayla Cheree Dibenedetto Jan 2009

Life History Characteristics Of Alligator Gar, Atractosteus Spatual, In The Bayou Dularge Area Of Southcentral Louisiana, Kayla Cheree Dibenedetto

LSU Master's Theses

The alligator gar Atractosteus spatula is a large, long-lived, physostomous fish that inhabits aquatic habitats throughout the central U.S., ranging from Oklahoma southward to the Gulf of Mexico. Unfortunately, the alligator gar has declined significantly in abundance throughout much of its historic range and is now considered vulnerable to localized extirpation. The goal of this study was to provide basic data on the ecology and life history of a commercially-exploited alligator gar population in south Louisiana. This study also focused on age determination and alternate aging techniques such as sectioned otoliths and sectioned scales. From 10 April 2007 through 21 …

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Provenance Studies Of Volcanic Clasts From The Santa Fe Group, San Luis Basin, Colorado: A Guide To Tectonic Evolution, Corine Kay Armstrong Jan 2009

Provenance Studies Of Volcanic Clasts From The Santa Fe Group, San Luis Basin, Colorado: A Guide To Tectonic Evolution, Corine Kay Armstrong

LSU Master's Theses

Volcanic clasts at the base of the Tertiary Santa Fe Group of the San Luis Basin (SLB), a major extensional feature of the northern Rio Grande Rift, provide evidence for the direction of sediment transport and timing of regional tectonic events. A combination of clast whole rock geochemistry (major and trace element), mineral chemistry (amphibole, biotite, pyroxene and feldspar) and geochronology (40Ar/39Ar of amphibole and biotite and U-Pb of zircons) is used to constrain the possible source scenarios. Several potential sources with requisite geochemical and geochronological information exist for the Santa Fe Group volcanic clasts including rocks from Spanish Peaks …

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Preparation Of The Chinese Sweet Leaf Tea Extract And Its Anti-Obesity Effect In Rodents, Gar Yee Koh Jan 2009

Preparation Of The Chinese Sweet Leaf Tea Extract And Its Anti-Obesity Effect In Rodents, Gar Yee Koh

LSU Master's Theses

The aqueous leaf extract of Rubus suavissimus (Chinese sweet leaf tea) was active in inhibiting angiogenesis, which could be used to suppress adipogenesis and cause weight loss. Following this revelation and approach, the anti-obesity effect was thoroughly investigated in normal and obese rat models. The investigations began with the preparation of quality-controlled extract. First, the crude extraction methods were examined leading to the characterization of the chemical composition. Second, the impure components were removed by alcohol precipitation and column chromatography, resulting in a standardized sweet leaf tea extract (RUS). Third, three bioavailable compounds identified from the urine analyses were re-constituted …

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Population Characteristics Of A White-Tailed Deer Herd In A Bottomland Hardwood Forest Of South-Central Louisiana, Justin W. Thayer Jan 2009

Population Characteristics Of A White-Tailed Deer Herd In A Bottomland Hardwood Forest Of South-Central Louisiana, Justin W. Thayer

LSU Master's Theses

White-tailed deer are an important economic and recreational resource in Louisiana. A basic understanding of population dynamics is essential to ensure sound management, but baseline information in Louisiana is lacking. Likewise, the notion of Quality Deer Management (QDM) continues to gain momentum in Louisiana. Our objectives were to evaluate space use, survival, and mortality for a deer herd managed under a QDM regime in south Louisiana. We captured 65 deer in West Baton Rouge and Iberville Parishes during 2007 and 2008, radio-marked 37 males and 11 females, and ear-marked an additional 10 males and 7 females. Home ranges (95%) for …

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Fine- To Basin-Scale Distributions Of Calanus Finmarchicus And Its Predators In Three Deep Basins Of The Gulf Of Maine During December 1998 And 1999 From Video Plankton Recorder (Vpr) Data, Christian Briseño-Avena Jan 2009

Fine- To Basin-Scale Distributions Of Calanus Finmarchicus And Its Predators In Three Deep Basins Of The Gulf Of Maine During December 1998 And 1999 From Video Plankton Recorder (Vpr) Data, Christian Briseño-Avena

LSU Master's Theses

The calanoid copepod Calanus finmarchicus is broadly distributed in the North Atlantic, where it dominates the spring zooplankton biomass of shelf ecosystems. Calanus finmarchicus diapauses in the deep basins of the Gulf of Maine (GOM) during late-summer through early-winter. During diapause, predators that co-occur in regions of high copepod abundance may reduce survivorship through predation. Consequently it is important to measure the distribution patterns of C. finmarchicus and its predators. Two cruises were carried out during December of 1998 and 1999 in the GOM. Video Plankton Recorder (VPR) data collected in Wilkinson, Jordan and Georges Basins were used to describe …

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Dosimetric Evaluation Of A Delivery Verification And Dose Reconstruction Method For Helical Tomotherapy, Ricky Hesston Jan 2009

Dosimetric Evaluation Of A Delivery Verification And Dose Reconstruction Method For Helical Tomotherapy, Ricky Hesston

LSU Master's Theses

Purpose: To determine the dosimetric accuracy of a dose reconstruction method used for verification of helical tomotherapy delivery for three different clinical sites. Methods and Materials: A delivery verification and dose reconstruction method has been applied to helical tomotherapy treatment plans of three different treatment sites (head & neck, prostate and lung). Treatment plans were generated on a cylindrical measurement phantom (TomoPhantom) using contours, prescriptions and planning objectives taken from clinical patient plans of the three sites. Film and ion chamber measurements were made for each plan with and without intentional changes in the machine output [-4% to 4%] or …

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A Multi-Proxy Approach To Investigating The Latest Holocene (~4,500 Yrs. Bp) Vegetational History Of Catahoula Lake, Louisiana, Rebecca Ann Tedford Jan 2009

A Multi-Proxy Approach To Investigating The Latest Holocene (~4,500 Yrs. Bp) Vegetational History Of Catahoula Lake, Louisiana, Rebecca Ann Tedford

LSU Doctoral Dissertations

A multi-proxy investigation of sediments examined from Catahoula Lake, Louisiana has provided a record of late-Holocene vegetational changes, related to both hydrology and climate. This study integrates data from phytoliths, pollen, stable isotopes, magnetic susceptibility, and core sediment analysis. A modern phytolith analog assessed the phytoliths production in local plants and their modern soil sample distribution within the established lake vegetation zones. Fifty of the 76 species produced both distinctive and redundant phytoliths. The modern soil sample database indicates that phytoliths produced from both monocotyledon and dicotlyledon plant groups prove useful in distinguishing between forest and grassland communities and identifying …

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Ratio And Proportion: Mapping The Conceptual Field, Christina Vincent Jan 2009

Ratio And Proportion: Mapping The Conceptual Field, Christina Vincent

LSU Master's Theses

Ratio and proportion are central to the middle school mathematics curriculum, but the full scope and extent of this topic is not described in detail in most state curriculum standards. In this thesis, numerous textbooks from the past one hundred years are sampled, along with several state‟s standards and the Louisiana state comprehensive curriculum. These sources are used to develop a more defined map of ratio and proportion as a conceptual field and a structured collection of problems. Proportional reasoning involves three phases: 1) the comparison of two magnitudes, expressed as ratio or rate, 2) the comparison of two ratios, …

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Inestigation Of The Energy Variation On A Tomotherapy Hi-Art Ii Using An Aluminum Stepwedge, Todd Racine Jan 2009

Inestigation Of The Energy Variation On A Tomotherapy Hi-Art Ii Using An Aluminum Stepwedge, Todd Racine

LSU Master's Theses

Purpose: To determine the sensitivity of a topographic stepwedge procedure to energy variations in a helical tomotherapy system. Method and Materials: Topographic procedures were followed using an aluminum stepwedge suspended in air on the end of the couch for a TomoTherapy HI-Art II system. Exit detector data from these procedures, collected and processed using TomoTherapy quality assurance (TQA) software were used to determine the effective beam energy. Energy sensitivity tests of the technique were made by varying the injector current. Topographic procedures were run daily over the lifetime of an x-ray target. Additionally, water phantom scanning data (lateral profiles and …

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Using Demographic Models To Manage Chinese Privet (Ligustrum Sinense Lour.), Metha Martine Klock Jan 2009

Using Demographic Models To Manage Chinese Privet (Ligustrum Sinense Lour.), Metha Martine Klock

LSU Master's Theses

Colonization of natural areas by Chinese privet (Ligustrum sinense Lour.) threatens biodiversity and preservation of native habitat in the southeastern United States. High rates of seed production and dispersal, coupled with clonal growth, result in a competitive advantage when introduced to novel areas. Land managers have attempted to control L. sinense through prolonged flooding, prescribed fire, and herbicide application with little success. I determined presence of L. sinense invasion in four sites in Louisiana and assessed key reproductive, growth, and survivorship characteristics defining its life course. I used vegetation surveys, germination trials, dendrochronology, and demographic models to elucidate stages in …

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Integrated Technology: Does It Affect Learner Outcomes?, Adam Ross Barrett Jan 2009

Integrated Technology: Does It Affect Learner Outcomes?, Adam Ross Barrett

LSU Master's Theses

Because technology has become prevalent in classrooms, this study was undertaken to test whether the use of integrated technology, specifically computers and online activities, affects learner outcomes in a classroom setting. The outcomes from classes taught using integrated technology were compared to classes taught with traditional teaching strategies. Students in a 7th grade life-science class were given pre-tests and post-tests to determine their learning gains on the topics of genetics and photosynthesis. Each class was assigned different activities based on the subject. Each unit was covered in four 90 minute periods. When one set of classes was using integrated technology …

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