Physical Sciences and Mathematics Commons^™

Marketing Forest-Based Ecotourism In Sri Lanka: Predicting The Ecotourism Behavior And Defining The Market Segment Through A Behavioral Approach, Polwattage K. Perera

LSU Doctoral Dissertations

Tourism industry is one of the main drivers of the global economy and plays a key role in regional development. As negative environmental and socio-cultural impacts of mass tourism became apparent, the appeal of alternative forms of tourism, especially ecotourism, continued to gain a broad recognition. As a result, ecotourism became one of the fastest growing sectors in global tourism during the past decade. Being a fast-developing country with ample natural resources, Sri Lanka can benefit from adopting and promoting ecotourism. At present, Sri Lanka’s ecotourism resources remain largely under-utilized. With rising demand, ecotourism operators are under pressure to meet …

Efficient Replica-Exchange Across Distributed Production Infrastructure, Abhinav S. Thota

LSU Master's Theses

Replica-Exchange (RE) methods represent a class of algorithms that involve a large number of loosely-coupled ensembles and are used to understand physical phenomena -- ranging from protein folding dynamics to binding affinity calculations. We develop a framework for RE that supports different replica pairing and coordination mechanisms, that can use a wide range of production cyberinfrastructure concurrently. Additionally, our framework uses a flexible pilot-job implementation, which enables effective resource allocation for multiple replicas. We characterize the performance of two different RE algorithms - synchronous and asynchronous - at unprecedented scales on production distributed infrastructure (Teragrid and LONI). The synchronous RE …

The Effect Of Habitat Change On Nutrient Removal In The Atchafalaya River Basin, Louisiana, Amy E. Scaroni

LSU Doctoral Dissertations

The Mississippi and Atchafalaya rivers are the major sources of freshwater and nutrients to the Gulf of Mexico. Increased nutrient loads from these rivers exacerbate eutrophication in coastal receiving waters and contribute to the large area of hypoxia that develops seasonally in the Gulf. Levees along the Mississippi River have reduced contact between the river and the historic floodplain; this limits the ability of floodplain wetlands to naturally mitigate excess nutrients. However, the Atchafalaya River diverges from the Mississippi 217 km from the Gulf and enters a large river floodplain with a widely spaced levee system. This enhances the ability …

Oceanic Light Absorption Properties: Assessment And Characterization In The Southeastern Bering Sea Using Field And Satellite Observations, Puneeta Suresh Naik

LSU Doctoral Dissertations

In recent decades the Bering Sea has been subjected to large climatic variability with cascading consequences on its productive marine ecosystem. Long-term as well as short-term monitoring is essential if we are to maintain its capability to supply the resources on which the national and local economy depend. Remote sensing together with in-situ and laboratory measurements of physical, biological and optical properties have considerable potential for monitoring and measuring the effects of climate-driven changes on this ecosystem. A major shortcoming to obtain accurate estimates of optically active components (such as colored dissolved organic matter, non-algal particulate matter, and phytoplankton) from …

Variability In Red Snapper Otolith Microchemistry Among Gulf Of Mexico Regions, Michelle Zapp Sluis

LSU Doctoral Dissertations

Red snapper, Lutjanus campechanus, has been an economically important reef fish in the Gulf of Mexico (Gulf) for over 150 years and is currently overfished. Catch statistics and demographic differences have lead to the population being categorized into eastern and western substocks divided by the Mississippi River, but data is recombined to set a Gulf-wide annual catch limit. The two objectives of this study were to apply otolith nursery chemical signatures to estimate red snapper mixing dynamics in the western Gulf, and to determine if signatures based upon trace metals associated with oil and gas platforms could discriminate between region …

Studies Of Inhomogeneous Superconducting States In Novel Materials, Robert Pearson Beaird

LSU Doctoral Dissertations

I provide detailed studies of two types of novel superconducting systems. In the first, I examine the effect of thermal (Gaussian) magnetic fluctuations on the superconducting transition of paramagnetically-limited superconductors under a Zeeman magnetic field. I consider transitions into both the uniform and the modulated (Fulde-Ferrell-Larkin-Ovchinnikov) superconducting states. I derive the Landau free energy expansion in powers of the superconducting order parameter, allowing for competition between the magnetic fluctuations and the superconducting order. I determine the order of the transition at the upper critical field and find that the fluctuations drive the transition, usually second-order, to first order at intermediate …

Excluded-Minor Characterization Of Apex-Outerplanar Graphs, Stanislaw Dziobiak

LSU Doctoral Dissertations

It is well known that the class of outerplanar graphs is minor-closed and can be characterized by two excluded minors: K_4 and K_{2,3}. The class of graphs that contain a vertex whose removal leaves an outerplanar graph is also minor-closed. We provide the complete list of 57 excluded minors for this class.

Soft Sediment Relay Zones: A High Resolution Seismic Survey Livingston Parish, Louisiana, Erin T. Elliott

LSU Master's Theses

The southern coast of the United States, bordering the Gulf of Mexico, is home to several down-to-the-south, listric, normal fault systems striking parallel to the coast. One of these, the Baton Rouge–Tepetate Fault System located in southern Louisiana, consists of a series of near-surface, reactivated growth faults and relay ramps– a broad area of ductile strain, with contemporaneous sedimentation. Evidence of recent fault and relay ramp movement is seen in surficial fault line scarps and offset roads. This thesis utilizes two near-surface (<500 >m), high-resolution (10 - 300 Hz), continuous seismic reflection profiles (360 m and 480 m long, 3 …

Social Vulnerability In Louisiana's Upper Industrial Corridor: Spatial Distribution And Linkages With Cumulative Pollution - A Zip Code Level Analysis, María Belén Toscano

LSU Master's Theses

Louisiana’s industrial corridor, the stretch of the lower Mississippi River from New Orleans to Baton Rouge, is one of the areas with the highest concentration of petrochemical facilities and chemical plants in the United States, as well as one of the most heavily polluted. In particular, the present study examined the associations of social vulnerability and potential exposure to environmental pollution in the upper section of the industrial corridor, the Baton Rouge Metropolitan Statistical Area (MSA). The study was based on the methodology developed by Cutter et al. (2003) to construct an empirically derived index to measure social vulnerability to …

Hurricane Induced Land And Vegetation Changes In The Breton Sound Estuary And Chandeleur Islands Using Landsat 5 Tm, Vandana Varshini Raghunathan

LSU Master's Theses

This study focuses on hurricane-induced changes in land and vegetation primarily in two study areas, the Breton Sound Estuary and the Chandeleur Islands, southeast of New Orleans, Louisiana. Breton Sound Estuary consists of the Caernarvon Diversion, a fresh water diversion of the Mississippi River that supplies this region with managed pulses of fresh water and sediments. The Chandeleur Islands are a chain of barrier islands that are uninhabited and transgressive in nature. A sequence of hurricanes in the past two decades has greatly altered both areas significantly. Satellite data were analyzed for a period of 24 years (1987-2011) of Breton …

Some Classes Of Graphs That Are Nearly Cycle-Free, Lisa Warshauer

LSU Doctoral Dissertations

A graph is almost series-parallel if there is some edge that one can add to the graph and then contract out to leave a series-parallel graph, that is, a graph with no K₄-minor. In this dissertation, we find the full list of excluded minors for the class of graphs that are almost series-parallel. We also obtain the corresponding result for the class of graphs such that uncontracting an edge and then deleting the uncontracted edge produces a series-parallel graph.

A notable feature of a 3-connected almost series-parallel graph is that it has two vertices whose removal leaves a …

Estimating Greenhouse Gas Emissions In Louisiana At The Parish Scale, Quang Tran

LSU Master's Theses

The estimation of greenhouse gas (GHG) emissions and removals from the atmosphere at the county scale is an interest to many local decision makers and scientists looking to plan, track, mitigate, or reduce concentrations at the local or regional level. This thesis presents a new approach in downscaling state-level emissions to contiguous county levels using the state of Louisiana as an example. Here, we applied the volume- preserving principle in an attempt to improve existing methods and fully characterize accurate GHG emissions at the county (i.e., parish) level. All six “Kyoto” GHG emissions related to sources and sectors were assessed …

Provenance And Origin Of Holocene Beach Ridge And Modern Beach Sands From The Costa De Nayarit, Western Mexico, Ruben Abe Cisneros

LSU Master's Theses

The Costa de Nayarit in western Mexico is a classic modern example of the progradation of a coastline in a wave-dominated depositional environment. Throughout the Pleistocene, sediments have been brought to the Costa De Nayarit via three major river systems, the Rio Grande de Santiago, the Rio San Pedro and the Rio Acaponeta. These river systems obtain their sediments from two distinctly different volcanic provinces within central Mexico, the Sierra Madre Occidental (SMO), a volcanic province characterized by its predominance of felsic volcanism (rhyolites) and pyroclastic flows (welded ash flow tuff and ignimbrite), and the Trans-Mexican Volcanic Belt (TMVB), which …

Small And Medium Enterprise Agricultural Producers And Forest Landowners Attitudes And Perceptions Towards New Bio-Based Paths To Prosperity: A Pilot Study In Louisiana And Mississippi, Roger D. Smithhart

LSU Master's Theses

Energy producers, developers, legislators, policy makers, and the public are searching for alternative energy sources to alleviate energy demands and dependency on fossil fuels. Of the renewable energy sources, biomass from forestry, crop, and animal residues offer a clean and sustainable solution to help mitigate climate issues and stabilize energy needs. However, most forests and farms in the U.S. are privately owned. It’s important to understand forest landowners’, agricultural producers’, and poultry producers’ attitudes and perceptions towards management activities intended for producing bio-based products. Three surveys were conducted tailored for each group. We surveyed 3,500 small to medium forest landowners …

Geomicrobiology Of Louisiana Coastal Marshes Before And After The Deepwater Horizon Oil Spill, Chang Liu

LSU Master's Theses

The 2010 Deepwater Horizon oil spill in the Gulf of Mexico not only impacted open ocean and shoreline geochemical and ecological environments, but it served to promote research of microbial ecosystems in poorly studied habitats, such as Louisiana marshes. Sediment and water samples from four main marshes in southern Louisiana were collected in May 2010 (pre-oil), September 2010 (oiled), and June 2011 (post-oil). Sites near the Mississippi River had exceptionally low salinity in the immediate months following the oil spill due to freshwater diversion efforts; salinity increased by an order of magnitude one year later. Microbial diversity was evaluated from …

Fraction Proficiency In Gifted Middle School Students, Lauren Alissa Lejeune

LSU Master's Theses

This thesis presents a program to develop fraction proficiency in gifted students who have skipped grades. The program was piloted with 31 gifted and advanced students in grades 6 and 7, and qualitative data on their performance is presented. Also presented here is a test of fraction proficiency that was developed to determine the level that students achieved at the end of the pilot program. The results of this test are presented and analyzed. The net contribution of this work is to present a starting point for a set of catch-up lessons on operations with fractions and to present a …

Spatiotemporal Responses Of Macroinvertebraes To Timber Harvesting In Low-Gradient Headwater Streams Of Central Louisiana, Derrick Klimesh

LSU Master's Theses

Macroinvertebrates are reflective of their nearby environment and are popularly used to detect changes in water quality. In this thesis research, macroinvertebrates were collected to investigate aquatic effects of timber harvesting operations with and without the use of best management practices (BMPs) in a forested, low-gradient, subtropical watershed in central Louisiana. Habitat assessments, physicochemical and hydrologic measurements, and macroinvertebrate sampling were conducted nine times from 2006 to 2010 during the spring and late summer, at 13 site locations ranging from plot level to watershed outlet. Timber harvesting occurred in September of 2007. A total of 86,183 macroinvertebrates were identified from …

Fate Of Mississippi River Diverted Nitrate On Vegetated And Non-Vegetated Coastal Marshes Of Breton Sound Estuary, Christine M. Vanzomeren

LSU Master's Theses

The Caernarvon Diversion meters Mississippi River water into coastal marshes of Breton Sound. Elevated levels of nitrogen in river water have sparked concerns that nutrient loading may affect marsh resilience and belowground biomass, as evidence from several marsh fertilization studies. These concerns resulted from observation that fresh and brackish Breton Sound marshes suffered extensive damage from Hurricane Katrina. The goal of this study is to determine the fate of nitrate (the dominant inorganic nitrogen form in the Mississippi River) in Breton Sound Estuary marshes. We hypothesized that most nitrate would be removed by denitrification and that nitrate loading would not …

Temporal Changes In Quality Of Life And Environment In New Orleans After Hurricane Katrina, Danielle Johanna Larock

LSU Master's Theses

Understanding and assessing the spatial and temporal changes of quality of life and environment of a community is critical to its sustainable development, especially after a disaster strikes. This study explores an approach that integrates remote sensing with socioeconomic data to assess the temporal changes in quality of life and environment (QOL) using Orleans Parish as an example. Hurricane Katrina, which struck New Orleans in 2005, has had vast implications economically, socially, and environmentally for this city and the surrounding area. Empirically quantifying these concepts will help to rebuild the city more sustainably. This study investigated change in environmental quality …

Factors Structuring Zooplankton Density And Composition Within A Louisiana River And Floodplain Tributaries With Emphasis On Hydrologic Processes, William Lowe Sheftall Iv

LSU Master's Theses

Zooplankters are important members of freshwater communities, facilitating the transfer of energy from primary production to higher trophic levels. Lentic floodplain systems are important in providing zooplankters with adequate habitat for growth and reproduction. Recently, The Nature Conservancy has been interested in cataloguing the aquatic taxa that inhabit the Ouachita River and floodplain in northern Louisiana, concurrent with an attempt to reestablish a river-floodplain connection with the river and eastern floodplain (the Mollicy Farms Unit, part of the Upper Ouachita National Wildlife Refuge). Sampling was conducted at seven sites along the Ouachita River and western floodplain monthly for one year …

Evaluation Of Selected Plant Products As Dietary Protein Sources For Florida Pompano (Trachinotus Carolinus), Gregory Lech

LSU Master's Theses

Profitability of aquaculture enterprises worldwide has been affected by rising fish meal prices. Plant proteins are promising replacements for fish meal because of their lower cost and worldwide availability. The goal of this research was to provide nutritional information for the development of all-plant diets for Florida pompano by evaluating growth of fish fed soy-based, fish-meal-free diets and assessing the nutritional value of several plant protein sources. In the first experiment, juvenile Florida pompano were fed five, soy-based, fish-meal-free diets containing graded levels of soybean meal (SBM, or M) at 0, 20, 25, 30, or 35%, with the remaining protein …

A Look At The Integration Of Wetlands And Hazard Mitigation Planning In Coastal Louisiana, Kathleen Melissa Bowers

LSU Master's Theses

Due to the destruction of the damaging hurricanes of 2005, Katrina and Rita, more effort has gone into the rebuilding and prevention of future disasters along the Louisiana coast than ever before. This research focuses on the use of wetlands, in the ten coastal parishes of Louisiana, as a mitigation effort aiding in the protection of coastal communities. Using content analysis and decision support software, a wetland ranking was created that represents how wetlands are utilized and protected within each parish. Criteria gathered from the plans include how many times wetlands were mentioned, collaboration with the state and other agencies, …

Response Of Disturbance-Dependent Breeding Bird Communities To Two Site Preparations In Loblolly Pine Plantations, Falyn Leann Owens

LSU Master's Theses

Disturbance-dependent birds throughout the United States have recently experienced significant declines due to fire suppression and conversion of wilderness to human-dominated landscapes. In Louisiana, young loblolly pine plantations are an important source of early- successional habitat for these specialist birds. However, changes in management practices may affect forest stand suitability for bird communities that rely on them. Here I examined how changes in two site preparations, tree row spacing [14 ft (4.3 m) vs. 20 ft (6.1 m)] and arrangement of post-harvest woody debris (piled vs. scattered), impacted breeding, disturbance- dependent birds. During four summers in 2006-2010, observers conducted point …

Parallel Surrogate Detection In Large-Scale Simulations, Lei Jiang

LSU Master's Theses

Simulation has become a useful approach in scientific computing and engineering for its ability to model real natural or human systems. In particular, for complex systems such as hurricanes, wildfire disasters, and real-time road traffic, simulation methods are able to provide researchers, engineers and decision makers predicted values in order to help them to take appropriate actions. For large-scale problems, the simulations usually take a lot of time on supercomputers, thus making real-time predictions more difficult. Approximation models that mimic the behavior of simulation models but are computationally cheaper, namely "surrogate models", are desired in such scenarios. In the thesis, …

Sensor-Based Autonomous Pipeline Monitoring Robotic System, Jong-Hoon Kim

LSU Doctoral Dissertations

The field of robotics applications continues to advance. This dissertation addresses the computational challenges of robotic applications and translations of actions using sensors. One of the most challenging fields for robotics applications is pipeline-based applications which have become an indispensable part of life. Proactive monitoring and frequent inspections are critical in maintaining pipeline health. However, these tasks are highly expensive using traditional maintenance systems, knowing that pipeline systems can be largely deployed in an inaccessible and hazardous environment. Thus, we propose a novel cost effective, scalable, customizable, and autonomous sensor-based robotic system, called SPRAM System (Sensor-based Autonomous Pipeline Monitoring Robotic …

Data-Aware Workflow Scheduling In Heterogeneous Distributed Systems, Dengpan Yin

LSU Doctoral Dissertations

Data transferring in scientific workflows gradually attracts more attention due to large amounts of data generated by complex scientific workflows will significantly increase the turnaround time of the whole workflow. It is almost impossible to make an optimal or approximate optimal scheduling for the end-to-end workflow without considering the intermediate data movement. In order to reduce the complexity of the workflow-scheduling problem, most researches done so far are constrained by many unrealistic assumptions, which result in non-optimal scheduling in practice. A constraint imposed by most researchers in their algorithms is that a computation site can only start the execution of …

Selection And Enumeration Of Low Epcam Expressing Breast Cancer Ctcs Using A High Throughput Microfluidic Device, Brandy Charon Snowden

LSU Master's Theses

Breast cancer cells overexpress EpCAM that can be used as a marker to select breast cancer CTCs from heterogeneous clinical samples, even when present in low abundance. This study used MDA-MB-231 cells which have a low expression level of EpCAM (1.7 x 103 binding sites per cell.3) Herein, we will report on the use of antiEpCAM antibodies immobilized onto the surface of a capture bed poised within a PMMA microchip that was fabricated into an HTMSU used for selection of breast cancer CTCs seeded into a buffer solution. The microchannel walls within the capture bed were UV modified for 5, …

Characterization Of Photon Counting Czt Detectors For Medical X-Ray Imaging And Spectroscopy, Shannon Fritz

LSU Doctoral Dissertations

Purpose: The purpose of this research was to characterize a photon counting cadmium zinc telluride (CZT) detector for medical x-ray imaging and spectroscopy purposes. The overall aim was to characterize CZT detector properties and to develop modifications and correction methods to address the limiting factors, making the detector clinically viable. Methods: Hole trapping issues were investigated through simulation and experiments with a large area single pixel CZT detector under three different irradiation geometries: edge-on, surface-on, and tilted angle irradiation. Characteristic x-ray escape was simulated using Monte Carlo methods and compared to measurements with a small pixel CZT imaging detector. Monoenergetic …

Homodyne Detection For Laser-Interferometric Gravitational Wave Detectors, Tobin Thomas Fricke

LSU Doctoral Dissertations

Gravitational waves are ripples of space-time predicted by Einstein's theory of General Relativity. The Laser Interferometer Gravitational-wave Observatory (LIGO), part of a global network of gravitational wave detectors, seeks to detect these waves and study their sources. The LIGO detectors were upgraded in 2008 with the dual goals of increasing the sensitivity (and likelihood of detection) and proving techniques for Advanced LIGO, a major upgrade currently underway. As part of this upgrade, the signal extraction technique was changed from a heterodyne scheme to a form of homodyne detection called DC readout. The DC readout system includes a new optical filter …

Crystal Growth Of Complex Intermetallics In Search For Heavy Electron Systems, Brenton L. Drake

LSU Doctoral Dissertations

The structural solution and physical property characterization of several Ln-T-Al/Ga and Ln-T-Al-Si contain phases, which include Ln(Cu,Al)12 (Ln = Y, Ce, Pr, Sm, and Yb), Ln(Ag,Al,Si)2 (Ln = Ce and Gd), LnCu2(Al,Si)5 (Ln = La and Ce), Ln(Cu,Al,Ga)13-x (Ln = La, Ce, Pr, and Eu), α and β LnNiGa4 (α Ln = Y and Gd – Yb; β Ln = (Tb – Er)), and Ln4FeGa12 (Ln = Tb – Er) will be presented in this work with an emphasis on crystal growth. The systems cover a large breadth of phase space and serve to illustrate the new and rich chemistry …