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Articles 1681 - 1710 of 3417

Full-Text Articles in Physical Sciences and Mathematics

A Characterization Of Almost All Minimal Not Nearly Planar Graphs, Kwang Ju Choi Jan 2013

A Characterization Of Almost All Minimal Not Nearly Planar Graphs, Kwang Ju Choi

LSU Doctoral Dissertations

In this dissertation, we study nearly planar graphs, that is, graphs that are edgeless or have an edge whose deletion results in a planar graph. We show that all but finitely many graphs that are not nearly planar and do not contain one particular graph have a well-understood structure based on large Möbius ladders.

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Subsurface Stratigraphic Architecture Of Pleistocene Sediments In The Greater New Orleans Area, James Ayrer Jan 2013

Subsurface Stratigraphic Architecture Of Pleistocene Sediments In The Greater New Orleans Area, James Ayrer

LSU Master's Theses

A major environmental and economic problem currently faces the New Orleans area, in southeastern Louisiana, stemming from salinization of freshwater aquifers that are important resources for the community. Major pumping of these aquifers has altered the potentiometric flow, allowing saltier bodies of water to flow into the region. The impact of pumping wells on encroachment of saltwater and the time as well as the route for saltwater to travel from the current saltwater-freshwater interface to pumping centers is not well constrained. Water planners need additional information to make decisions about future management of groundwater resources. The most effective way to …

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Acoustic Biomass Of Fish Associated With An Oil And Gas Platform Before, During, And After "Reefing" It In The Northern Gulf Of Mexico, Grace Elizabeth Harwell Jan 2013

Acoustic Biomass Of Fish Associated With An Oil And Gas Platform Before, During, And After "Reefing" It In The Northern Gulf Of Mexico, Grace Elizabeth Harwell

LSU Master's Theses

With over ~2600 oil and gas platforms (platforms) remaining in the northern Gulf of Mexico (Gulf), the Gulf States have access to one of the most unique fisheries in the world. Because of high abundances of game fishes around platform legs and the popular belief that platforms enhance fish stocks, both Louisiana and Texas have created artificial reef programs based upon the decommissioning of platforms. As oil and gas fields continue to be retired, oil and gas companies may find that “reefing” or toppling a platform may be a more economically viable alternative to complete removal of material. Questions remain …

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Impact Of Iudr In Rat 9l Glioma Cell Survival For 25-35 Kev Photo-Activated Auger Electron Therapy, Diane Alvarez Jan 2013

Impact Of Iudr In Rat 9l Glioma Cell Survival For 25-35 Kev Photo-Activated Auger Electron Therapy, Diane Alvarez

LSU Master's Theses

Introduction: Photo-activated Auger electron therapy is a potential technique that could preferentially target cancer cells. This binary therapy uses a drug containing a high-Z element like iododeoxyuridine (IUdR), which serves as a radiosensitizer and molecular carrier of high-Z iodine into cancer cell DNA. Iodine becomes the Auger electron source when activated by photons with an appropriate energy. This work studied the survival of rat 9L glioma cells with IUdR replacing thymidine in the DNA. Irradiations at monochromatic energies above and below the iodine K-edge (33.2 keV) are part of a larger study from 25-70 keV. It was hypothesized that SER10 …

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Effects Of Stress And Water Saturation On Seismic Velocity And Attenuation In Near Surface Sediments, James Michael Crane Jan 2013

Effects Of Stress And Water Saturation On Seismic Velocity And Attenuation In Near Surface Sediments, James Michael Crane

LSU Doctoral Dissertations

Seismic investigation in the near-surface is complicated by highly attenuating media, large interparticle stresses, and variable water saturation, so new tools and methodology are necessary to understand the relationships between velocity, attenuation, and physical properties of the propagating media. A new shear wave source is developed for investigation of gas-charged, organic-rich sediments because compressional waves are highly attenuated and currently available sources are inadequate. The new source compares favorably to a traditional hammer impact source, producing a signal with a broader-band of frequencies (30-100Hz cf. 30-60Hz) and signal-to-noise ratios (SNR) equivalent to ~3 stacked hammer blows to the hammer impact …

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Searching For New Gamma-Ray Sources Using Earth Occultation Imaging With The Cgro/Burst And Transient Source Experiment, Yuan Zhang Jan 2013

Searching For New Gamma-Ray Sources Using Earth Occultation Imaging With The Cgro/Burst And Transient Source Experiment, Yuan Zhang

LSU Doctoral Dissertations

Earth occultation provides a means of monitoring gamma-ray sources over the entire sky. This technique has been demonstrated with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) active from 1991 to 2000, and is now being used with the Gamma-ray Burst Monitor (GBM) instrument on the Fermi mission. Although this approach provides a powerful wide field monitoring capability, the BATSE and GBM implementations of this technique have so far limited the analysis to a catalog of previously identified sources. In this dissertation, an indirect imaging method is described that permits searching for unknown sources …

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The Effects Of Peer Instruction On Ninth Grade Students' Conceptual Understanding Of Forces And Motion, Nicole Congine Harvey Jan 2013

The Effects Of Peer Instruction On Ninth Grade Students' Conceptual Understanding Of Forces And Motion, Nicole Congine Harvey

LSU Master's Theses

Because students are often taught physics in a traditional, lecture-based classroom, the present study was undertaken to test whether the use of peer instruction, specifically concept questions embedded within a PowerPoint that allows for students to interact throughout the lecture, affects learner outcomes in a classroom setting. The outcomes from classes taught using peer instruction were compared to classes taught with traditional, lecture-based teaching strategies. Students in five different sections of a 9th grade Physical Science class were given pre-tests and post-tests to determine their learning gains on the topics of motion and forces. In the first unit of instruction, …

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Predicting Mechanical Properties Of Southern Pine Lumber With Nondestructive Measurements, Jacob Romer Jan 2013

Predicting Mechanical Properties Of Southern Pine Lumber With Nondestructive Measurements, Jacob Romer

LSU Master's Theses

Predictive models were developed for stiffness and bending strength of southern pine 2x6, eight ft. lumber using nondestructive measurements of stresswave velocity, density and visual characteristics such as knots, slope of grain and rate of growth. To account for local areas of weakened material due to knots and slope of grain, a grid system was developed to quantify general knot size and location. Multiple regression models were created using these physical and visual measurements. Two sets of models were developed: one that removed influential samples with abnormal wavespeeds (greater than 18,000 ft./s) indicative of poor wood quality; and, models that …

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Temporal And Spatial Variations In The Subsurface Salinity Of Lake Charles, Louisiana : An Investigation Of Saline Sources, Alexandria Suding Jan 2013

Temporal And Spatial Variations In The Subsurface Salinity Of Lake Charles, Louisiana : An Investigation Of Saline Sources, Alexandria Suding

LSU Master's Theses

One of the most pressing issues facing groundwater managers is saltwater intrusion. In coastal Louisiana this issue is especially prevalent. One location that is currently threated by saltwater intrusion is the industrial area of Lake Charles, Louisiana, where three high chloride areas have been detected within the underlying Chicot aquifer. Three sand units of the Chicot aquifer are present in Lake Charles: the 200-foot (200’) sand, the 500’ sand, and the 700’ sand. Groundwater with elevated chloride concentrations was first noticed by industries in the early 1970s. An initial investigation determined that the northern and southern bodies had formed by …

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A Clay Mineral Provenance Study Of The Northern Pandora Trough Continental Margin, Gulf Of Papua, Ashley Len Howell Jan 2013

A Clay Mineral Provenance Study Of The Northern Pandora Trough Continental Margin, Gulf Of Papua, Ashley Len Howell

LSU Master's Theses

X-ray diffraction mineralogy of western-, central-, and eastern-derived fluvial sediments within the Gulf of Papua exhibits distinct and mixed clay mineral assemblages. These mineral assemblages allow for a better understanding of how a thick muddy continental margin shelf-edge depocenter in the eastern Gulf of Papua of latest Pleistocene/early Holocene age formed, as well as connections between terrestrial sediment delivery and evolution of deep-sea deposits in this region. Modern clay mineralogy reveals a high to low gradation of illite/smectite values from the western to eastern Gulf of Papua (Slingerland et al., 2008a), which is applied to the recent past for provenance …

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Silica Polypeptide-Based Colloids: Physical Properties And Novel Materials, Cornelia Rosu Jan 2013

Silica Polypeptide-Based Colloids: Physical Properties And Novel Materials, Cornelia Rosu

LSU Doctoral Dissertations

The investigation of polypeptide composite particles, PCPs, is described. The production of mesoporous and polycolloid architectures is also addressed. PCPs were prepared by both growing form and grafting to method. They consist of a core made of silica, silica-coated magnetite or silica-coated cobalt. Some of the particles were covalently labeled with fluorescein isothiocyanate. Several polypeptides were chosen for attachment on the core: poly(γ-stearyl-L-glutamate), PSLG, poly(Nε-carbobenzyloxy-L-lysine), PCBL and poly(o-benzyl-L-tyrosine), PBTY. Attachment of a well-characterized alkyne-end terminated PSLG and PCBL to an azide- functionalized particle yielded PCPs with a desired sparse coverage. A blend of techniques such as FTIR, XPS, TEM, HTEM, …

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Adaptive Stochastic Conjugate Gradient Optimization For Temporal Medical Image Registration, Huanhuan Xu Jan 2013

Adaptive Stochastic Conjugate Gradient Optimization For Temporal Medical Image Registration, Huanhuan Xu

LSU Master's Theses

We propose an Adaptive Stochastic Conjugate Gradient (ASCG) optimization algorithm for temporal medical image registration. This method combines the advantages of Conjugate Gradient (CG) method and Adaptive Stochastic Gradient Descent (ASGD) method. The main idea is that the search direction of ASGD is replaced by stochastic approximations of the conjugate gradient of the cost function. In addition, the step size of ASCG is based on the approximation of the Lipschitz constant of the stochastic gradient function. Thus, this algorithm could maintain the good properties of the conjugate gradient method, meanwhile it uses less gradient computation time per iteration and adjusts …

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Scattering Off Of An Unusual Boundary, Jerome Weston Jan 2013

Scattering Off Of An Unusual Boundary, Jerome Weston

Honors Theses

No abstract provided.

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Effects Of Deepwater Horizon Oil On The Growth Rates And Pigment Composition Of Phytoplankton Isolated From Grand Isle, La, Jie Li Jan 2013

Effects Of Deepwater Horizon Oil On The Growth Rates And Pigment Composition Of Phytoplankton Isolated From Grand Isle, La, Jie Li

LSU Master's Theses

This research focused on the effects of un-weathered Macondo crude oil on the growth rates and pigment ratios of phytoplankton isolated from Grand Isle, LA. The experiments involved incubating nutrient-enriched artificial media containing a range of oil concentrations up to 19.2 ppm with small aliquots of coastal water from Grand Isle and measuring the growth rates of the phytoplankton during the subsequent 10–14 days and the pigment ratios of the phytoplankton at the end of log-phase growth to determine whether the crude oil affected the growth rate of the phytoplankton and their composition in terms of pigment ratios. Pigment analysis …

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Leadership In Environmental And Energy Design : A True Sustainable Development Model?, Christopher Jay Loser Jan 2013

Leadership In Environmental And Energy Design : A True Sustainable Development Model?, Christopher Jay Loser

LSU Master's Theses

Suburban sprawl and sustainable development has received increasing worldwide attention over the past few decades. In 1998, sustainable development principles were codified in the Leadership in Energy and Environmental Design (LEED) certification system. The most recent LEED certification system to be released, LEED for New Development (LEED-ND), includes sustainable development goals with the addition of smart growth principles intended to curb sprawl. This study examines and evaluates LEED-ND in order to determine if it meets the requirements of sustainable development to provide for the needs of future generations, as defined by the United Nation’s World Commission on Environment and Development. …

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Fish And Macroinvertebrate Assemblage Composition And Diversity At Revetted Banks In The Pearl River And The Response Of These Assemblages To A Paper Mill Effluent Spill, Jose Alexander Vazquez Jan 2013

Fish And Macroinvertebrate Assemblage Composition And Diversity At Revetted Banks In The Pearl River And The Response Of These Assemblages To A Paper Mill Effluent Spill, Jose Alexander Vazquez

LSU Master's Theses

The armoring of river banks with riprap can have detrimental effects on lotic ecosystems due to the subsequent alteration of hydrologic regimes; however, evidence suggests that riprap can also increase aquatic diversity in degraded systems. The goal of my study was to determine what impacts riprapped banks have on fish and macroinvertebrate assemblages in the Pearl River, which has a history of anthropogenic degradation. I collected fishes with an electrofishing boat from armored and natural banks at five regions during fall 2011, winter 2012, and summer 2012. I also collected macroinvertebrates with introduced substrates in fall 2011. Richness was analyzed …

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Natural Fracture Characterization In The Haynesville Shale, East Texas: A Core Study, Frank Leslie Morgan Jan 2013

Natural Fracture Characterization In The Haynesville Shale, East Texas: A Core Study, Frank Leslie Morgan

LSU Master's Theses

The Haynesville Shale in East Texas and Northwest Louisiana is one of the most studied and explored shale-gas plays in the United States. With new horizontal drilling and completion strategies, energy companies can produce hydrocarbons directly from the source rock making the Haynesville Shale an attractive resource. A key component of enhanced hydrocarbon production is the presence of natural fractures. They may serve as permeable pathways for hydrocarbon flow, especially in tight shales such as in the Haynesville Shale, where the matrix permeability is very low. In the case of the Haynesville Shale, little is known about the occurrence of …

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The Use Of Classroom Demonstrations To Improve High School Students' Ability To Understand Concepts In Chemistry, Jessica Langlois Shelton Jan 2013

The Use Of Classroom Demonstrations To Improve High School Students' Ability To Understand Concepts In Chemistry, Jessica Langlois Shelton

LSU Master's Theses

This study was completed to determine if implementing demonstrations in specific chapters of a high school chemistry classroom would enhance students understanding of the topics the demonstrations represented. The study consisted of five sections of college preparatory high school chemistry. The sections were made up of both male and female students. The sections were randomly broken up into two groups. Each group acted as the experimental and control at different points in the study. Four chapters were used in the study. Each group represented the control group in two chapters and the experimental group in two chapters, flip flopping with …

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Community Resilience To Coastal Hazards : An Analysis Of Two Geographical Scales In Louisiana, Chi Li Jan 2013

Community Resilience To Coastal Hazards : An Analysis Of Two Geographical Scales In Louisiana, Chi Li

LSU Master's Theses

Quantifying resilience is difficulties due to the different definitions of resilience, the interchangeable uses with two other terms “vulnerability” and “adaptability”, as well as the lack of consensus on what indicators should be selected to quantifying resilience. This thesis research studied the community resilience in Louisiana by applying the Resilience Inference Measurement (RIM) model at two geographic levels: county level and zip code level. The RIM model accesses resilience by using three dimensions (exposure, damage, and recovery) and two abilities (vulnerability and adaptability). The types of coastal hazards included in this study were: coastal, flooding, hurricane/tropical storm, tornado, and severe …

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Metacognition And Its Effect On Learning High School Calculus, Bonnie Sue Bergstresser Jan 2013

Metacognition And Its Effect On Learning High School Calculus, Bonnie Sue Bergstresser

LSU Master's Theses

The following paper discusses the effect of metacognitive training sessions on students’ calculus retention. Students in two high school classes participated. The students in both classes were then given lessons on a chapter without metacognitive training and lessons on a subsequent chapter with training in a set of metacognitive skills. After the latter chapter students scored higher on a post-test and expressed desire to incorporate the skills they learned into their other classes.

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Matrix-Assisted Laser Desorption Ionization Mass Spectrometry For Identificaiton Of Shrimp, Venkatesulu Salla Jan 2013

Matrix-Assisted Laser Desorption Ionization Mass Spectrometry For Identificaiton Of Shrimp, Venkatesulu Salla

LSU Master's Theses

Matrix-assisted laser desorption ionization (MALDI) time of flight mass spectrometry was used to identify shrimp at the species level using commercial mass spectral fingerprint matching software (Bruker Biotyper). In the first step, a mass spectrum reference database was constructed from the analysis of six shrimp species that are commercially important in the United States: L. setiferus, F. azticus, S. brevirostris, P. robustus, P. dispar and P. platyceros. In the second step, the reference database was tested using 74 unknown shrimp samples from these six species. Correct identification was achieved for 72 of the 74 samples (97 percent): 72 samples were …

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An Evaluation Of Oyster Stocks, Grow-Out Conditions, And Off-Bottom Culture Methods For Increasing Commercial Production Of Eastern Oysters (Crassostrea Virginica) In The Northern Gulf Of Mexico, Justin Morgan Leonhardt Jan 2013

An Evaluation Of Oyster Stocks, Grow-Out Conditions, And Off-Bottom Culture Methods For Increasing Commercial Production Of Eastern Oysters (Crassostrea Virginica) In The Northern Gulf Of Mexico, Justin Morgan Leonhardt

LSU Master's Theses

This project examined the ecologically and economically valuable eastern oyster (Crassotrea virginica) in Louisiana with two field experiments. Little information has been gathered on the performance of local Louisiana oyster stocks and no study has focused on a comparison of stocks among variable estuarine conditions. Additionally, the use of alternative grow-out methods and intensive cage aquaculture has never been evaluated in Louisiana. For the first study, a dermo-resistant stock of oysters (LSU-OYS: ‘OBOY’) was compared to three wild oyster stocks along a salinity gradient. The objectives of this study were to determine the optimal oyster stock(s) and the ideal grow-out …

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Incorporating Calculus Concepts Into A Middle School Classroom, Randie Barbera Bailey Jan 2013

Incorporating Calculus Concepts Into A Middle School Classroom, Randie Barbera Bailey

LSU Master's Theses

The Common Core State Standards for Mathematics were released in June of 2010 and full implementation into our schools is being required in the fall of 2013. The standards require teachers and students to be more focused and rigorous in what they teach and learn. This shift in learning towards focus, coherence, fluency, deep understanding, and applications was to improve math education in the United States so that our students become more competitive in the global economy of the 21st century and to help more students to be college and career ready by grade twelve. It is now necessary for …

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Using Writing Assignments In High School Geometry To Improve Students' Proof Writing Ability, Amanda Choppin Mcallister Jan 2013

Using Writing Assignments In High School Geometry To Improve Students' Proof Writing Ability, Amanda Choppin Mcallister

LSU Master's Theses

The Common Core State Standards encourage the use of writing in mathematics classrooms. This study was designed to create a template for high school teachers to use in a geometry class to improve students’ proof writing ability. The students enrolled in the class were asked to complete journal and expository writing assignments throughout the course. The assignments were scored with a rubric. To assess if growth was made in proof writing, the students were all given a test four times throughout the school year. All four tests were assessed using the same rubric. We provide evidence that the template was …

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Monitoring The Survival Of Hatchery-Produced Spat And Larvae On Louisiana Public Oyster Reefs, Erin R. Leonhardt Jan 2013

Monitoring The Survival Of Hatchery-Produced Spat And Larvae On Louisiana Public Oyster Reefs, Erin R. Leonhardt

LSU Master's Theses

Alternative or supplemental management activities may be necessary to restore and enhance oyster production on Louisiana public oyster reefs. The production of wild oysters is variable due to anthropogenic and environmental factors that affect recruitment, growth and survival. The availability and structure of cultch material for larval recruitment and survival is particularly important to maintain oyster production. Beginning in 2011, the Sea Grant Oyster Hatchery on Grand Isle, LA and the Louisiana Department of Wildlife and Fisheries (LDWF) collaborated to test the survival of hatchery-produced spat and hatchery-produced larvae deployed on public oyster grounds and cultch plant sites. In 2011, …

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Some Effects Of Nutrient And Flooding Stress Manipulation On Coastal Louisiana Wetland Vegetation, James Stephen Ialeggio Jan 2013

Some Effects Of Nutrient And Flooding Stress Manipulation On Coastal Louisiana Wetland Vegetation, James Stephen Ialeggio

LSU Master's Theses

Freshwater diversions are a relatively recently utilized tool in wetland loss mitigation that stimulate an organic accretion response in marsh vegetation, which is based in root production and thus belowground biomass. The effectiveness of freshwater diversions in slowing marsh loss probably varies across a gradient of the factors they supply: decreased salinity, increased nutrient concentrations, and increased inundation. Flooding stress is commonly thought to be the overriding factor limiting wetland vegetation growth, however its influence may vary across salinity and nutrients. Therefore, plugs of Spartina patens were planted in four “marsh organs” consisting each of 36 sediment-filled PVC pipes of …

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Statistical Classification Problems In Assessment Of Teachers, Xuan Wang Jan 2013

Statistical Classification Problems In Assessment Of Teachers, Xuan Wang

LSU Master's Theses

Classification and regression trees form an important and indispensable tool in data analysis and classification problems. Class trees are described in detail with examples. The method is applied to a data set pertaining to evaluation of teachers. In addition, two other classification methods, bagging and AdaBoost are explained. These methods improve existing classifiers to nearly optimal classifiers.

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Oligomers Of Beta-L-Arabinosides Of Hydroxyproline : Synthesis Of The Carbohydrate Epitope Of The Art V 1 Allergen, Ning Xie Jan 2013

Oligomers Of Beta-L-Arabinosides Of Hydroxyproline : Synthesis Of The Carbohydrate Epitope Of The Art V 1 Allergen, Ning Xie

LSU Doctoral Dissertations

The pollen of mugwort is a major contributor to hay fever in Europe and North America. The chemical structure of Art v 1, the major allergen of mugwort, has been elucidated. A notable motif in Art v 1 – characterized by clusters of contiguous â-arabinosides of hydroxyproline – was found to be a key recognition element for antibodies generated in response to the natural protein. This dissertation details the chemical synthesis of oligomers of â-arabinosides of hydroxyproline and the search to establish the minimal carbohydrate epitope of Art v 1. The â-arabinoside motif, being a 1,2-cis glycoside, presents a considerable …

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High Resolution Tephra And U/Pb Chronology Of The 3.33 – 3.26 Ga Mendon Formation, Barberton, Greenstone Belt, South Africa, Nicholas Burns Decker Jan 2013

High Resolution Tephra And U/Pb Chronology Of The 3.33 – 3.26 Ga Mendon Formation, Barberton, Greenstone Belt, South Africa, Nicholas Burns Decker

LSU Master's Theses

The Mendon Formation in the Barberton Greenstone Belt of South Africa marks the boundary between the Onverwacht and Fig Tree Groups. These groups are characterized by mafic to ultramafic volcanism and felsic volcanism with related epiclastic sedimentation, respectively. This transition marks the end of komatiitic volcanism in the Barberton Greenstone Belt and is accompanied by numerous impact-related spherule layers. This study characterizes the upper Mendon Formation texturally and geochemically over a wide areal extent and across structure and facies change in an attempt to better understand the evolution of tectonic processes at this boundary. A suite of whole rock and …

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Strongly Correlated Ultra-Cold Bosonic Atoms In Optical Lattices, Kalani Hettiarachchilage Jan 2013

Strongly Correlated Ultra-Cold Bosonic Atoms In Optical Lattices, Kalani Hettiarachchilage

LSU Doctoral Dissertations

A major focus in condensed matter physics is to study the origin of exotic quantum phases such as coexistent and inhomogeneous phases, quantum criticality, and secondary ordered phases close to quantum critical points. Exotic phenomena in strongly correlated systems occur due to competing complex interactions of spin, charge, lattice, and orbital degrees of freedom. Complex quantum phases in strongly correlated systems are challenging, but they might be very useful due to their possible functionality to make advance devices. In order to understand, utilize, and optimize such behaviors, we need to improve our understanding of these systems. Studies in cold atom …

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