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

Physical Sciences and Mathematics Commons

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

Articles 1 - 18 of 18

Full-Text Articles in Physical Sciences and Mathematics

Road Associated Wildlife Mortality In An Urbanizing Metropolitan Area Of The Southeastern Usa, Lillian Miller Apr 2016

Road Associated Wildlife Mortality In An Urbanizing Metropolitan Area Of The Southeastern Usa, Lillian Miller

Honors Theses

No abstract provided.


Pesticide Partitioning In Louisiana Wetland Aand Ricefield Sediment, Brendan Michael Marsh Jan 2016

Pesticide Partitioning In Louisiana Wetland Aand Ricefield Sediment, Brendan Michael Marsh

LSU Master's Theses

Pesticides are used globally and are often found within bodies of water. The EPA investigates the potential environmental impact through computer modeling in order to help mitigate some of the regulatory burden of pesticide fate investigation. Currently when pesticides enter a water body, the Exposure Analysis Modeling System (EXAMS) estimates partitioning depth as 5 cm and assumes equal distribution. This assumption was tested with a wide variety of pesticides with varying Koc ranges and water solubilities. Savillex 150 ml Teflon tubes were filled with wetland and ricefield sediments with fresh and seawater as the aqueous phase. The seven pesticides tested …


Living On The Edge: An Assessment Of The Habitat Use Of Waterbirds In Estuarine Wetlands Of Barataria Basin, La, Brett Ashley Patton Jan 2016

Living On The Edge: An Assessment Of The Habitat Use Of Waterbirds In Estuarine Wetlands Of Barataria Basin, La, Brett Ashley Patton

LSU Master's Theses

The wetlands of Louisiana are losing area at the rapid rate of 42.9 km2 yr-1 and the trend is expected to continue. This combined with expected sea-level rise will likely cause large shifts in vegetation and salinity regimes that will affect the wildlife species reliant on these ecosystems. Waterbirds serve as indicator species of ecosystem health in estuarine wetland habitats; therefore, these species are often the targets of wetland management goals in Louisiana. However, many proposed wetland restoration projects are focused primarily on social impacts with only a few specific waterbird species designated for management. The majority of these waterbird …


Quantitative Oil Source-Fingerprinting Techniques And Their Application To Differentiating Crude Oil In Coastal Marsh Sediments, Buffy Marie Meyer Jan 2016

Quantitative Oil Source-Fingerprinting Techniques And Their Application To Differentiating Crude Oil In Coastal Marsh Sediments, Buffy Marie Meyer

LSU Doctoral Dissertations

Oil source-fingerprinting is an environmental forensics technique that uses analytical chemistry to determine the origin of oil residues in environmental samples by comparison to a known or suspected source oil. Currently, the only standardized method for oil source fingerprinting is a qualitative approach that is very effective in almost every oil spill response situation. However, the need for quantitative oil source-fingerprinting methods to complement the qualitative determinations is extremely desired. The research herein aims to utilize data generated by gas chromatography/mass spectrometry (GC/MS) methodologies to test two different quantitative techniques: diagnostic biomarker ratio analysis and chemometrics. The most common crude …


Ecological-Hydrological Feedback In Forested Wetlands, Scott Thomas Allen Jan 2016

Ecological-Hydrological Feedback In Forested Wetlands, Scott Thomas Allen

LSU Doctoral Dissertations

In forested wetlands, the biotic and abiotic consequences of water level variability is not well understood. The effects of flooding on carbon and water exchanges are important knowledge gaps where progress could benefit management of natural resources and predicting of changes in surface geophysical cycles. Two specific needs are a better understanding of (1) wetland tree responses to hydrologic variations, and (2) the effects of the forest and associated tree stressors on surface energy and water fluxes. Objectives were to determine effects of flooding on evaporation rates and energy dynamics, tree water use and growth responses to river-floodplain connectivity and …


Vegetation Influences Microbial Community Structure And Methane Emissions In Southeastern Louisiana Wetlands, Anthony Jason Rietl Jan 2016

Vegetation Influences Microbial Community Structure And Methane Emissions In Southeastern Louisiana Wetlands, Anthony Jason Rietl

LSU Doctoral Dissertations

Methane has a warming potential 28 times that of carbon dioxide and has been increasing in the Earth’s atmosphere since 1750. An understanding of the dynamics of methane emissions from natural sources is becoming increasingly important as we may need to mitigate emissions from these sources in the future to help reduce the effects of climate change. Wetlands are the single largest natural source of methane; however, little attention has been given to how plant species, biota, and interactions between above and belowground communities and microbial communities may affect methane emissions. First, microbial community structure and function was assessed for …


Immune Gene Variation And Susceptibility To Upper Respiratory Tract Disease In Gopher Tortoises, Jean Pierre Elbers Jan 2016

Immune Gene Variation And Susceptibility To Upper Respiratory Tract Disease In Gopher Tortoises, Jean Pierre Elbers

LSU Doctoral Dissertations

The immune system defends the host from bacteria, fungi, parasites, and viruses. The immune system is partially under genetic control through immune response genes, such as those of the major histocompatibility complex (MHC) whose nucleotide variation influences the host’s ability to recognize foreign pathogens and can influence disease susceptibility. Populations of threatened species generally possess low levels of genetic variation, and genetically depauperate hosts may be at greater risk of infectious disease contributing to extirpations because they also possess low immunogenetic variation. My dissertation examines the relationship between immunogenetic variation and disease susceptibility and the factors that influence innate immune …


Application Of Biomass Derived Materials In Nanocomposites And Drilling Fluids, Kunlin Song Jan 2016

Application Of Biomass Derived Materials In Nanocomposites And Drilling Fluids, Kunlin Song

LSU Doctoral Dissertations

Tar is inevitably produced from biomass thermochemical processes, and is often disposed as an industrial waste, leading to environmental pollution. As a result of its high carbon content, tar was expected to be a promising precursor for manufacturing carbon materials. Consequently, low-cost porous carbon nanofibers (CNFs) using tar, polyacrylonitrile (PAN), and silver nanoparticles was fabricated through electrospinning and subsequent stabilization and carbonization processes. The continuous electrospun nanofibers were obtained with diameters ranging from 392 to 903 nm. The addition of biomass tar resulted in increased fiber diameters, reduced thermal stabilities, and slowed cyclization reactions of PAN in the as-spun nanofibers. …


Biomass Gasification For Electricity Generation: An Integrated Approach For Development Of Forest Residue-Based Projects In Rural India, Anand Mishra Jan 2016

Biomass Gasification For Electricity Generation: An Integrated Approach For Development Of Forest Residue-Based Projects In Rural India, Anand Mishra

LSU Doctoral Dissertations

Biomass gasification is generally regarded as a promising technology for various advanced application in energy production. Biomass is the only carbon-based sustainable option among the renewable energy sources. This study is focused on fostering biomass gasification for electricity generation sector in India. The study addresses four broad aspects of biomass gasification for electricity generation - feedstock properties and gasification technology, policy and regulatory framework governing the sector, financial evaluation of electricity generation from biomass gasification, and feedstock supply. The study is divided in four chapters, each of which addresses one aspect of electricity generation through biomass gasification. Based on literature, …


Arsenic Speciation And Phytoremediation Modeling For Environmental Management, Sidney Joseph Marlborough Jan 2016

Arsenic Speciation And Phytoremediation Modeling For Environmental Management, Sidney Joseph Marlborough

LSU Doctoral Dissertations

Arsenic has been used throughout recorded history but during the industrial revolution widespread use led to global environmental impact. The two forms that should be considered in environment management are arsenate and arsenite. The calculations of environmental risk for arsenic exposure relies the toxicity of arsenite however, in well aeriated surface soils arsenate may be the predominate form. Ecological risk assessments based on arsenite studies will lead to restrictive remediation requirements that do not adequately reflect the level of risk. Arsenate resembles phosphate and as such has a greater affinity for phytoremediation. Phytoremediation is one of the most viable and …


Temporal Dynamics Of Benthic Responses To Habitat Disturbance In Coastal Plain Headwaters Of Southwestern Louisiana, Catherine Elizabeth Murphy Jan 2016

Temporal Dynamics Of Benthic Responses To Habitat Disturbance In Coastal Plain Headwaters Of Southwestern Louisiana, Catherine Elizabeth Murphy

LSU Doctoral Dissertations

Weak biotic responses to habitat gradients within Northern Gulf of Mexico streams have been attributed to spatial and temporal variability. Landscape and in-stream habitat descriptions are presented for watersheds within Pleistocene terraces of the Coastal Plains geomorphic province of Louisiana, USA. Geologic influences on stream habitat were inferred by comparing multivariate ordinations on physicochemical measurements between terraces. Seasonal variability was assessed during a drought year (2011) and a typical water year (2013). Within coastal plains of Louisiana, stream condition was more similar within terraces than within river basins. Permutational MANOVA models indicated significantly different stream habitat between Uplands and Prairie, …


Infectivity And Physiological Effects Of White Spot Syndrome Virus (Wssv) In Farmed Louisiana Red Swamp Crayfish (Procambarus Clarkii), Barcley Talon Pace Jan 2016

Infectivity And Physiological Effects Of White Spot Syndrome Virus (Wssv) In Farmed Louisiana Red Swamp Crayfish (Procambarus Clarkii), Barcley Talon Pace

LSU Master's Theses

The red swamp crayfish, Procambarus clarkii, represents an important aquaculture species responsible for over half of all commercial aquaculture profits in Louisiana. White spot syndrome virus (WSSV) is highly pathogenic and induces mass mortality in crustacean aquaculture operations worldwide. Crayfish lack the adaptive ability of the vertebrate immune system, and must depend on primitive, innate immune responses to combat viral infections. This study aims to investigate the dose-response of WSSV in P. clarkii and to examine viral-host interactions by examining the biochemical and immunological changes induced by WSSV infection in this species. Viable viral particles were isolated from naturally infected …


The Photodegradation Of 2,6-Dichloro-4-Nitroaniline (Dcna) In Freshwater And Saltwater, Emily Noelle Vebrosky Jan 2016

The Photodegradation Of 2,6-Dichloro-4-Nitroaniline (Dcna) In Freshwater And Saltwater, Emily Noelle Vebrosky

LSU Master's Theses

The fungicide 2,6-dichloro-4-nitroaniline (DCNA) is applied to crops grown in areas near both freshwater and saltwater bodies and it can enter the surface waters where it is susceptible to photolysis; limited information is published on the photodegradation of DCNA. It has been shown that the salinity of seawater can influence both the overall rate of degradation of chemicals and impact the distribution and types of photoproducts generated during the photodegradation processes of a pesticide. The photodegradation of DCNA was measured in distilled water, artificial seawater, estuarine water, and phosphate buffer to determine the degree of differences in the degradation rate …


Influences On The Successful Implementation Of The Convention On Wetlands Of International Importance (Ramsar) Among Member Countries, Aziza Saud Al Adhoobi Jan 2016

Influences On The Successful Implementation Of The Convention On Wetlands Of International Importance (Ramsar) Among Member Countries, Aziza Saud Al Adhoobi

LSU Master's Theses

Wetlands are very dynamic ecosystems and are featured all over the world’s landscape. Recent studies suggested that wetlands are in continuous decline, both and quantity and quality and between 64-71% is the estimated global wetland loss in the 20th century (Davidson 2014; Gardner et al., 2015). Therefore, as wetland loss increases around the world, more effort to protect and restore wetland habitat, values, and services become crucial. For this reason, the Ramsar Convention was established four decades ago to highlight the severity of wetland loss and to produce guidelines that aim to guide Contracting Parties toward sustainable and efficient management …


Relative Resistance To Breaking Of Pinus Taeda L. And Pinus Palustris, Cory Glenn Garms Jan 2016

Relative Resistance To Breaking Of Pinus Taeda L. And Pinus Palustris, Cory Glenn Garms

LSU Master's Theses

Patterns from hurricane damage give an indication that longleaf pine (Pinus palustris) is more windfirm than loblolly pine (Pinus taeda). Tree windfirmess has been attributed to many factors including species and material properties like wood strength and stiffness. Because longleaf pine wood is stronger and stiffer than loblolly pine wood, this study used static winching methodology to see if these properties account for differences in windfirmness by measuring bending force required to break stems (MMAX). Stress-strain diagrams were constructed for pulled trees to explore how they behave under increasing loads. Based on these diagrams, it appears that living trees can …


Evaluating Survival Of Released Ranched American Alligator In Coastal Louisiana, Kristy Durham Capelle Jan 2016

Evaluating Survival Of Released Ranched American Alligator In Coastal Louisiana, Kristy Durham Capelle

LSU Master's Theses

Since 1986, Louisiana’s American alligator (Alligator mississippiensis) ranching program has required the release of alligators produced from eggs collected from wild nests to maintain wild populations. This project assessed long-term harvest data (1991-2010s) to estimate survival of released alligators. First, wildlife and fishery harvest models and general inter-disciplinary survival models were evaluated to determine best fit to the data. Second, once the best fitting model was selected, release length, precipitation and temperature from release sites, and an index of hunter effort were added to investigate influences on survival estimates. Release length was included because over time the proportion and size …


Effects Of Landscape Fragmentation On Land Loss, Weijia Cheng Jan 2016

Effects Of Landscape Fragmentation On Land Loss, Weijia Cheng

LSU Master's Theses

Coastal Louisiana, the seventh largest delta on earth, is one of the most vulnerable coastal areas in the United States of America (USA) because of its land loss problem. Coastal land loss is usually caused by many complicated factors. With the rapid increase in human activities, more studies on land loss have focused on the anthropogenic elements, but less on the pattern of the landscape. It is expected that the type of spatial arrangement, such as high degree of fragmentation, would affect the degree of land erosion. A quantitative evaluation of coastal landscape fragmentation and its influences on land loss …


Efficacy And Feasibility Of Alginate Bait For The Louisiana Commercial Blue Crab (Callinectes Sapidus) Fishery, Elizabeth Lorraine Clowes Jan 2016

Efficacy And Feasibility Of Alginate Bait For The Louisiana Commercial Blue Crab (Callinectes Sapidus) Fishery, Elizabeth Lorraine Clowes

LSU Master's Theses

Louisiana leads all U.S. states in blue crab (Callinectes sapidus) landings, but high fuel and bait costs have hindered commercial fishing productivity of Louisiana in recent years. The primary baitfish, Atlantic menhaden (Brevoortia tyrannus), has steadily increased in price and decreased in availability, while crab prices remain low. To reduce costs for fishermen, an alternative bait was developed that incorporates shrimp waste into a semi-rigid alginate matrix. Lab testing and preliminary field tests show that shrimp-alginate bait may be a suitable alternative to menhaden for Louisiana crab fishermen. I evaluated bait performance by conducting field sampling to compare catch rates …