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

Physical Sciences and Mathematics Commons™

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

Louisiana State University

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 961 - 990 of 3417

Full-Text Articles in Physical Sciences and Mathematics

Manipulating Physical Properties Of Complex Materials By Processing, Mohammad Saghayezhian Jan 2017

Manipulating Physical Properties Of Complex Materials By Processing, Mohammad Saghayezhian

LSU Doctoral Dissertations

Transition metal oxides (TMOs) are a class of materials in which charge, orbital, spin and lattice strongly interact with each other. In the present thesis, a special attention is paid to the physical properties of TMOs as a function of processing. First, TMOs are studied as substrates, where the surface is of prime importance. Second, the thin films are fabricated and their physical properties are presented. The SrTiO3 (001) and (111) surfaces are weakly and strongly polar and the free energy of intact surfaces should diverge. It is shown that in TiO2 terminated SrTiO3(001) the top most layer shows rumpling …

Go to article

Nanoscale Studies Of Proteins And Thin Films Using Scanning Probe Microscopy, Zachary Lane Highland Jan 2017

Nanoscale Studies Of Proteins And Thin Films Using Scanning Probe Microscopy, Zachary Lane Highland

LSU Doctoral Dissertations

Nanostructures of organosilanes, thin metal films, and protein nanopatterns were prepared and analyzed with atomic force microscopy (AFM). Organosilanes with designed functional groups were used to selectively pattern green fluorescent protein at the nanoscale using protocols developed with particle lithography. Mesospheres are deposited onto a substrate to produce a surface mask. Organosilanes are deposited to form a matrix film surrounding nanopores for depositing proteins. The nanopatterns were characterized using AFM, after steps of particle lithography for directly visualizing surface changes. Studies with AFM also provide a compelling tool for teaching undergraduates to introduce concepts of nanoscience. An undergraduate laboratory was …

Go to article

Design, Synthesis, And Evaluation Of Innovative Bodipy-Peptidic Conjugates For Biological Application, Tyrslai Menyaee Williams Jan 2017

Design, Synthesis, And Evaluation Of Innovative Bodipy-Peptidic Conjugates For Biological Application, Tyrslai Menyaee Williams

LSU Doctoral Dissertations

Abstract Chapter 1 provides a brief introduction to colorectal cancer (CRC), methods of detection, photodynamic therapy (PDT), and EGFR as an attractive targeting strategy for imaging CRC. Chapter 2 details the synthesis of ten peptide sequences for targeting EGFR receptors at the site of CRC, as a collaborative work with Dr. Seetharama Jois. This chapter also investigates the efficacy of these peptides for EGFR. Chapter 3 offers the first synthetic strategy for developing BODIPY-peptide conjugates via amide linkages. All conjugates were optimized for the best reaction conditions and good yields were observed. Each conjugate was subjected to photophysical, SPR, and …

Go to article

A Palynostratigraphic Investigation Of Holocene Coastal Texas Bays: Implications For Future Coastal Change, Shannon Marie Ferguson Jan 2017

A Palynostratigraphic Investigation Of Holocene Coastal Texas Bays: Implications For Future Coastal Change, Shannon Marie Ferguson

LSU Doctoral Dissertations

Although the Gulf of Mexico is one of the most studied basins in the world, a majority of the focus has been driven by petroleum exploration and/or on seismic and sedimentological facies models. Rarely has the intent of previous studies been to characterize the Holocene climatic record of coastal Texas. Of those studies that discuss Holocene vegetation change, the majority focus on the Mississippi River Delta, the Edwards Plateau or central Florida, leaving an absence of insight to western Gulf of Mexico climate changes. The Texas coastline stretches 595 km across almost 4° of latitude and the strong northwestern precipitation …

Go to article

Succinct Data Structures For Parameterized Pattern Matching And Related Problems, Arnab Ganguly Jan 2017

Succinct Data Structures For Parameterized Pattern Matching And Related Problems, Arnab Ganguly

LSU Doctoral Dissertations

Let T be a fixed text-string of length n and P be a varying pattern-string of length |P| <= n. Both T and P contain characters from a totally ordered alphabet Sigma of size sigma <= n. Suffix tree is the ubiquitous data structure for answering a pattern matching query: report all the positions i in T such that T[i + k - 1] = P[k], 1 <= k <= |P|. Compressed data structures support pattern matching queries, using much lesser space than the suffix tree, mainly by relying on a crucial property of the leaves in the tree. Unfortunately, in many suffix tree variants (such as parameterized suffix tree, order-preserving suffix tree, and 2-dimensional suffix tree), this property does not hold. Consequently, compressed representations of these suffix tree variants have been elusive. We present the first compressed data structures for two important variants of the pattern matching problem: (1) Parameterized Matching -- report a position i in T if T[i + k - 1] = f(P[k]), 1 <= k <= |P|, for a one-to-one function f that renames the characters in P to the characters in T[i,i+|P|-1], and (2) Order-preserving Matching -- report a position i in T if T[i + j - 1] and T[i + k -1] have the same relative order as that of P[j] and P[k], 1 <= j < k <= |P|. For each of these two problems, the existing suffix tree variant requires O(n*log n) bits of space and answers a query in O(|P|*log sigma + occ) time, where occ is the number of starting positions where a match exists. We present data structures that require O(n*log sigma) bits of space and answer a query in O((|P|+occ) poly(log n)) time. As a byproduct, we obtain compressed data structures for a few other variants, as well as introduce two new techniques (of independent interest) for designing compressed data structures for pattern matching.

Go to article

Numerical Study Of The Periodic Anderson Model With Holstein Phonons For The Description Of Cerium Volume Collapse, Enzhi Li Jan 2017

Numerical Study Of The Periodic Anderson Model With Holstein Phonons For The Description Of Cerium Volume Collapse, Enzhi Li

LSU Doctoral Dissertations

The volume collapse transition of Cerium has intrigued physicists since its discovery several decades ago. Various models and mechanisms have been proposed, the most prominent scenarios are based on the Mott transition and the Kondo volume collapse transition. In this study, we explore the volume collapse by a dynamical mean field theory (DMFT) study of the periodic Anderson model with electron-phonon coupling to the conduction band. This allows us to study the effect of the electron-phonon interaction on the volume collapse. In order to faithfully account for the volume collapse, we also include the effects due to the volume and …

Go to article

Development Of A Low-Energy Monoenergetic Electron Separator, Sergio Martín López Cáceres Jan 2017

Development Of A Low-Energy Monoenergetic Electron Separator, Sergio Martín López Cáceres

LSU Master's Theses

The aim of this project is to build a prototype device that can select electrons of certain energy in order to have a monoenergetic beam suitable for the characterization of radiation detectors. Current options for sources of electrons are either from radioisotopes or accelerator facilities. Radioisotope sources are not tunable in energy since they depend on the nuclear and atomic structures of the daughter nucleus. On the other hand, even though accelerators offer the feature of a variable energy beam, they have limited availability and are not typically run at low intensities. Therefore, the motivation for this thesis is the …

Go to article

Database Plan Quality Impact On Knowledge-Based Radiation Therapy Treatment Planning Of Prostate Cancer, Phillip Douglas Hardenbergh Wall Jan 2017

Database Plan Quality Impact On Knowledge-Based Radiation Therapy Treatment Planning Of Prostate Cancer, Phillip Douglas Hardenbergh Wall

LSU Master's Theses

Purpose: Knowledge-based planning (KBP) leverages plan data from a database of previously treated patients to inform the plan design of a new patient. This work investigated bladder and rectum dose-volume prediction improvements in a common KBP method using a Pareto plan database in VMAT planning for prostate cancer. Methods: We formed an anonymized retrospective patient database of 124 VMAT plans for prostate cancer treated at our institution. From these patient data, two plan databases were compiled. The clinical plan database (CPD) contained planning data from each patient’s clinical plan, which were manually optimized by various planners. The multi-criteria optimization database …

Go to article

Louisiana Birds Act As Reservoirs For Antibiotic-Resistant Bacteria, Collin T. Brown Jan 2017

Louisiana Birds Act As Reservoirs For Antibiotic-Resistant Bacteria, Collin T. Brown

LSU Master's Theses

Wild birds carry diverse microbial communities, including antibiotic-resistant bacteria (ARB). With the ever-increasing use of antibiotics in agricultural and clinical settings, genes that code for antibiotic resistance in bacteria have been selected for. These bacteria persist in the environment in a culturable state, but little is understood about communities of antibiotic-resistant bacteria in the environment. Birds with predictable behaviors may serve as useful indicators of these communities, and provide insights into how bacterial communities spread and evolve in the environment. To understand the utility of birds as indicators of the presence of antibiotic-resistant bacteria in the environment, we collected bacterial …

Go to article

A Study On User Demographic Inference Via Ratings In Recommender Systems, Changbin Li Jan 2017

A Study On User Demographic Inference Via Ratings In Recommender Systems, Changbin Li

LSU Master's Theses

Everyday, millions of people interact with online services that adopt recommender systems, such as personalized movie, news and product recommendation services. Research has shown that the demographic attributes of users such as age and gender can further improve the performance of recommender systems and can be very useful for many other applications such as marketing and social studies. However, users do not always provide those details in their online profiles due to privacy concern. On the other hand, user interactions such as ratings in recommender systems may provide an alternative way to infer demographic information. Most existing approaches can infer …

Go to article

In Search Of Antarctica's Last Vegetation Refugium Within The Mcmurdo Dry Valleys, David Rau Jan 2017

In Search Of Antarctica's Last Vegetation Refugium Within The Mcmurdo Dry Valleys, David Rau

LSU Master's Theses

The McMurdo Dry Valleys, a hyper-arid cold polar desert located within the Transantarctic Mountains was once covered by vegetation. An in depth study of surface samples of various Neogene age, acquired throughout the Valleys, provide insight to the location of one of Antarctica’s last vegetation refugia. Boston University’s Antarctic Research Group has collected 82 surface samples from paleo lake sediments on 14 expeditions spanning 22 years in the McMurdo Dry Valleys. The ages of the samples are still not fully constrained, but 8 regions where samples were collected have been interpreted to range between 16.95 ± 0.17 to 4 Ma …

Go to article

Species Richness And Abundance Of Freshwater Mussels In Tributaries Of The Lower Pearl River Basin, Corinne Nicole Bird Jan 2017

Species Richness And Abundance Of Freshwater Mussels In Tributaries Of The Lower Pearl River Basin, Corinne Nicole Bird

LSU Master's Theses

Freshwater mussels play a vital role in their ecosystems, influencing processes such as nutrient cycling and water filtration. In addition, they provide and improve habitat for other organisms. North America is home to the most species-rich freshwater bivalve fauna in the world, but most stream systems in the U.S. have been severely degraded, and future freshwater mussel extinction rates are estimated at 6.4 percent per decade. The Pearl River Basin is a significant area of aquatic species diversity and has a complex watershed land use mosaic, providing an excellent opportunity to investigate the relative importance of local and landscape level …

Go to article

Spatial Variability Of The Depth To The Magma Reservoir Beneath The Yellowstone Caldera Inferred From Observations Of Seiche Loading Induced Strain, Kevin James Gryger Jan 2017

Spatial Variability Of The Depth To The Magma Reservoir Beneath The Yellowstone Caldera Inferred From Observations Of Seiche Loading Induced Strain, Kevin James Gryger

LSU Master's Theses

Seiche waves in Yellowstone Lake at ~78, ~51, and ~25 minute periods and heights <10 cm can cause measurable strain (< 40 ns) as observed on borehole strainmeters both near (<300 m) and far (~20 km) from the lake. Observations of the correlation between the seiche waves and the associated strain response can be used to constrain the rigidity of the upper crust, the depth to magma bodies in the subsurface, and the viscosity (related to melt percentage) of the magma bodies in place. Lake level was directly measured with campaign absolute pressure gauges deployed in the West Thumb basin, Breeze Channel, and central basin of Yellowstone Lake, and 13 large seiche events (¡Ý7 cm) were identified from these observations. Periodic strain transients were measured on borehole strainmeters in the caldera during the 13 large seiche events. The peak-to-trough amplitude and phase of the seiche wave and strain response were estimated by fitting a multi-frequency sinusoid to the time series over a 4-hour window during each seiche event. It was found that the relationship between an applied seiche load and the associated strain response is self-consistent and linearly proportional at each borehole strainmeter in the caldera. Over multiple seiche events the observed strain response is consistent with a modeled strain-field produced by a seiche load on a two-layered viscoelastic model defined by free parameters Young¡¯s modulus (E1), plate thickness (H), and shear modulus ratio (¦Ì2/¦Ì1). The two-layered viscoelastic model represents a solid upper crust overlying a partially molten body which may be small pockets of melt (<1 km thickness) or a larger magma reservoir. Results suggest crystallizing melt beneath Yellowstone caldera at depths (H) of ~4¨C8 km in the south-southeast and ~3-5 km in the north-northwest sections of the caldera. Temporal observations between strain meters, coupled with constraints of Young¡¯s and shear moduli suggest that melt in the shallow crust has a viscosity ¡Ü1013 Pa s.

Go to article

Development Of The Focal Plane Instrumentation Of The Separator For Capture Reactions (Secar), Kyle Joerres Jan 2017

Development Of The Focal Plane Instrumentation Of The Separator For Capture Reactions (Secar), Kyle Joerres

LSU Master's Theses

The SEparator for CApture Reactions (SECAR) is currently being developed at the National Superconducting Cyclotron Laboratory (NSCL) and the future Facility for Rare Isotope Beams (FRIB) for measurements of nuclear reactions critical for understanding energy generation and element synthesis in stellar explosions. SECAR is an electromagnetic recoil separator designed for sensitive measurements of radiative capture reactions using beams of proton-rich, short-lived isotopes at the energies relevant for explosive environments such as Type I X-ray bursts and classical novae. SECAR is designed to efficiently separate capture reaction products of interest from the incident beam by up to a factor of 10^17 …

Go to article

Differential Responses Of Soil Greenhouse Gas Production And Denitrification To Salinity Alterations Along A Wetland Salinity Gradient, Natalie Ceresnak Jan 2017

Differential Responses Of Soil Greenhouse Gas Production And Denitrification To Salinity Alterations Along A Wetland Salinity Gradient, Natalie Ceresnak

LSU Master's Theses

Coastal wetlands provide several valuable services, such as carbon (C) storage and nitrogen (N) removal. Although wetlands serve as net C sinks, wetland soils release greenhouse gases (GHGs) including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Wetlands can buffer the influx of nitrate (NO3-) by transforming it into gaseous N (N2O, N2) through denitrification microbial pathway. Salinity is a regulator of soil biogeochemistry and long- (e.g. saltwater intrusion) and short-term (e.g. storm surges, river diversions) exposures may affect soil GHG production and denitrification. In this study, soil GHG production and denitrification enzyme activity (DEA) rates were examined over …

Go to article

Palynostratigraphy And Environmental Implication Of Organic-Walled Microfossils Recovered From Iodp Site U1435, Mitchell Clifford Gregory Jan 2017

Palynostratigraphy And Environmental Implication Of Organic-Walled Microfossils Recovered From Iodp Site U1435, Mitchell Clifford Gregory

LSU Master's Theses

Extensive studies have examined the syn- and post-rift sediments in the South China Sea and surrounding margins, but pre-rift, Eocene deposits are rare. Here we examine organic-walled microfossils from the South China Sea, recovered at Site U1435 of IODP Expedition 349 to provide palynostratigraphic control and characterize the environmental setting before, and in response to, the initiation of seafloor spreading in the basin ~33 Ma. The well preserved palynological assemblage recovered allow dating of sediments sampled at Site U1435. Units II and III are now subdivided in 4 subzones; Zone 1 is essentially barren, Zones 2 and 3A are assigned …

Go to article

On-Site Sperm Cryopreservation For Aquatic Repository Development And User Group Linkage, William Martin Childress Jan 2017

On-Site Sperm Cryopreservation For Aquatic Repository Development And User Group Linkage, William Martin Childress

LSU Master's Theses

Although on-site cryopreservation of aquatic species sperm in nitrogen-vapor shipping dewars has been used for more than 30 yr, many limitations remain. Due to the size of shipping dewars, most studies are small scale and can only produce tens of samples. The freezing temperatures that can be achieved are also affected by the size of the dewar and the number of samples being frozen due to the heat load. In addition, often due to timing or remote location these samples cannot be shipped, and if they are shipped, quality can be lost and the samples must be discarded. The goal …

Go to article

Modeling The Influence Of Energy And Climate Megatrends On Future Costs And Benefits Of Marsh Creation In The Mississippi Delta, Adrian R. H. Wiegman Jan 2017

Modeling The Influence Of Energy And Climate Megatrends On Future Costs And Benefits Of Marsh Creation In The Mississippi Delta, Adrian R. H. Wiegman

LSU Master's Theses

Over 25% of Mississippi delta (MRDP) wetlands were lost over the past century. There is currently a major effort to restore the MRDP focused on a 50-year time horizon, a period during which the energy system and climate will change dramatically. I modeled hydraulic dredging to sustain marsh from 2016-2066 and 2016-2100 under a range of scenarios for sea level rise, energy price, and management regimes. A marsh elevation model was calibrated to data from MRDP marshes. I developed a model to simulate dredging costs based on the price of crude oil and a project efficiency factor. Crude oil prices …

Go to article

Mining Social Media Data For Improved Understanding Of Disaster Resilience, Lei Zou Jan 2017

Mining Social Media Data For Improved Understanding Of Disaster Resilience, Lei Zou

LSU Doctoral Dissertations

Disaster resilience is the capacity of a community to ‘bounce back’ from disastrous events, by effecting resilience building activities through the four phases of emergency management – preparedness, response, recovery, and mitigation. However, data describing a community’s behaviors in each phase are difficult to access in traditional databases. Social media data provide an innovative data source to better understand communities’ responses and behaviors in each phase of emergency management during disasters, and thus could ultimately monitor and enhance disaster resilience. This study analyzes the spatial-temporal patterns of Twitter activities during Hurricane Sandy, which struck the northeastern United States on October …

Go to article

Sediment Transport And Slope Stability In The Northern Gulf Of Mexico, Jeffrey Blake Obelcz Jan 2017

Sediment Transport And Slope Stability In The Northern Gulf Of Mexico, Jeffrey Blake Obelcz

LSU Doctoral Dissertations

Sediment transport and slope stability are fundamental organizing agents of the geological record. These processes have been extensively studied along the northern margin of the Gulf of Mexico basin for both basic and applied purposes, but our knowledge of them is limited by the spatial and temporal sampling capabilities of traditional geologic oceanographic surveying tools such as coring, single-beam echosounders, and sidescan sonar. This dissertation seeks to update the state of knowledge regarding northern Gulf of Mexico sediment transport and slope stability from annual to millennial timescales, primarily using relatively high-resolution acoustic geophysical tools such as swath bathymetric echosounders and …

Go to article

Chemical Synthesis: New Methods For O-Glycosylation And The Preparation Of Organic Thin Films, Rashanique Deondria Quarels Jan 2017

Chemical Synthesis: New Methods For O-Glycosylation And The Preparation Of Organic Thin Films, Rashanique Deondria Quarels

LSU Doctoral Dissertations

This dissertation focuses on the diverse use of chemical synthesis. Herein, I will discuss the use of synthetic organic chemistry for the modification surfaces and the synthesis of small molecules. Chapter One is an introduction to the realm of surface chemistry. I have highlighted some key methods for surface modification. Additionally, methods to characterize the as-formed thin films are also outlined. In Chapter Two, I discuss the use of visible-light photoredox catalysis in the nanoscale lithography of Au(111) surfaces. Blue LED irradiation of solutions of NBDT in the presence of Ru(bpy)32+ results in the formation of p-nitrophenyl radicals that graft …

Go to article

Effect Of Metal Speciation In Fly Ash On Environmentally Persistent Free Radical Formation, Elisabeth Eileen Cook Jan 2017

Effect Of Metal Speciation In Fly Ash On Environmentally Persistent Free Radical Formation, Elisabeth Eileen Cook

LSU Doctoral Dissertations

Waste incineration and Superfund sites lead to the formation of pollutants harmful to both the environment and human health. Environmentally Persistent Free Radicals (EPFRs) are a class of newly discovered radical pollutants known to form on combustion by-products such as fly ash and particulate matter. EPFRs are rapidly gaining attention for their harmful effects on the environment and human health. Previous research has shown the formation of EPFRs through surface-mediated reactions with transition metal-oxides on particulates. The work presented in this dissertation explores the relationship between fly ash composition and EPFR formation. Fly ash production occurs from combustion systems, namely …

Go to article

Application Of Grating-Based Interferometry To Additive Manufacturing, Lithium-Ion Batteries, And Crystals, Adam Joseph Brooks Jan 2017

Application Of Grating-Based Interferometry To Additive Manufacturing, Lithium-Ion Batteries, And Crystals, Adam Joseph Brooks

LSU Doctoral Dissertations

X-ray and neutron imaging are convenient ways to non-destructively observe novel materials. X-rays provide advantages of low cost and high brilliance while neutrons show bulk and isotopic sensitivity. Imaging provides a way for observing chemical and physical properties of materials without the need for destruction. The way of the imaging future is utilizing imaging with grating-based interferometry. In comparison to traditional radiography and tomography, by using absorption and phase gratings in the beam path, the absorption, phase, and scattering of a sample can be detected. In essence, three image datasets can be obtained in one experiment, saving substantially on costs …

Go to article

Condition Of Birds In Amazonian Rainforest Fragments And Second-Growth Forests, Angelica Maria Hernandez Palma Jan 2017

Condition Of Birds In Amazonian Rainforest Fragments And Second-Growth Forests, Angelica Maria Hernandez Palma

LSU Doctoral Dissertations

Deforestation modifies otherwise intact expanses of forest into small, isolated fragments. In addition to fragmentation, deforestation also creates abrupt forest edges and large areas of regenerating vegetation where land is abandoned after clearing. Understanding how changes in the landscape affect the physical condition of birds is crucial for managing populations in human-modified landscapes. Here I use the biomarkers feather growth rate and feather quality (ptilochronology), fluctuating asymmetry (FA), and stress hormones from feathers (CORT), to estimate the physical condition of Amazonian understory birds living in forest fragments, second-growth forests, and continuous forests. Feather CORT revealed how fragmentation disrupts interspecific interactions; …

Go to article

Resonant Interactions In Strong Field Laser Physics, Seth Jacob Camp Jan 2017

Resonant Interactions In Strong Field Laser Physics, Seth Jacob Camp

LSU Doctoral Dissertations

We present a theoretical study of the influence of resonant enhancement on high harmonic generation for harmonics near the ionization threshold of helium and argon atoms. This is done by solving the time-dependent Schrodinger equation (TDSE) for the interaction between an atom and a driving laser pulse. By varying parameters of the driving laser pulse, we are able to identify the enhancement of harmonics resulting from multiphoton resonances between the ground state and Stark-shifted excited states of the atom. In this way, spectral and temporal signatures of resonant enhancement are identified and highlighted. We also study trajectory dynamics in HHG. …

Go to article

The Relationship Between The Timing Of Hydrocarbon Generation Between The Bristol Bay Depositional Basin And The Port Moller Area And Southern Portion Of The Bristol Bay Basin Of The Alaska Peninsula, Claire Rochelle Jones Jan 2017

The Relationship Between The Timing Of Hydrocarbon Generation Between The Bristol Bay Depositional Basin And The Port Moller Area And Southern Portion Of The Bristol Bay Basin Of The Alaska Peninsula, Claire Rochelle Jones

LSU Master's Theses

The Alaska Peninsula has been the target of oil and gas exploration throughout much of the 20th century. Although most exploration efforts have focused on the Cook Inlet area, the geological setting of the Alaskan Peninsula suggests that economically viable resources may be located further south on the northern side bordering Bristol Bay (Port Moller area). This study investigates the relation of petroleum system elements between the northern and southern section of the Alaskan Peninsula with a particular focus on the potential for petroleum accumulation on the southern section close to Herendeen Bay. The analysis included the integration of a …

Go to article

Decentralized Scheduling For Many-Task Applications In The Hybrid Cloud, Brian Lyle Peterson Jan 2017

Decentralized Scheduling For Many-Task Applications In The Hybrid Cloud, Brian Lyle Peterson

LSU Doctoral Dissertations

While Cloud Computing has transformed how we solve many computing tasks, some scientific and many-task applications are not efficiently executed on cloud resources. Decentralized scheduling, as studied in grid computing, can provide a scalable system to organize cloud resources and schedule a variety of work. By measuring simulations of two algorithms, the fully decentralized Organic Grid, and the partially decentralized Air Traffic Controller from IBM, we establish that decentralization is a workable approach, and that there are bottlenecks that can impact partially centralized algorithms. Through measurements in the cloud, we verify that our simulation approach is sound, and assess the …

Go to article

Development And Application Of A Modis Inorganic Sediment Model During The 2016 Mississippi River Diversion In Lake Pontchartrain, Louisiana, Robert Lee Iles Iv Jan 2017

Development And Application Of A Modis Inorganic Sediment Model During The 2016 Mississippi River Diversion In Lake Pontchartrain, Louisiana, Robert Lee Iles Iv

LSU Master's Theses

The Bonnet Carré Spillway (BCS) is a Mississippi River diversion located on the southwestern coastline of Lake Pontchartrain in Louisiana. The discharge of potentially high amounts of Mississippi River nutrients and sediments during BCS diversion events has a noted ecological impact on the Lake Pontchartrain estuary. Projected river flooding prompted the opening of the Spillway from 10 January to 1 February 2016. MODIS satellite images were aerosol-corrected and then compared to in-situ measurements of inorganic sediment concentration (ISC) to derive a predictive algorithm for estimating ISC (in mg L^-1) in Lake Pontchartrain for satellite images in January and February. The …

Go to article

The Effects Of Instrumental Noise On Searches For Generic Transient Gravitational Waves In Advanced Ligo, Marissa Walker Jan 2017

The Effects Of Instrumental Noise On Searches For Generic Transient Gravitational Waves In Advanced Ligo, Marissa Walker

LSU Doctoral Dissertations

One hundred years after Albert Einstein predicted the existence of gravitational waves as a result of his theory of general relativity, the Laser Interferometer Gravitational-Wave Observatory (LIGO), made the first direct detection of a gravitational-wave signal from a binary black hole merger, GW150914. GW150914 was found not only by search methods specifically developed to find the distinctive waveform produced by coalescing binaries, but also by generic searches designed to find any arbitrary short-duration signal in the LIGO data. The impact of noise on the searches must be carefully investigated in order to reduce the search background and enable confident gravitational-wave …

Go to article

Branch And Stem Growth As Affected By Loss Of Leaf Area On Selected Branches In Loblolly Pine, Shannon Dumo Kidombo Jan 2017

Branch And Stem Growth As Affected By Loss Of Leaf Area On Selected Branches In Loblolly Pine, Shannon Dumo Kidombo

LSU Doctoral Dissertations

Leaf area and crown dynamics control how trees grow through their supply of carbohydrates and growth regulators, and their influence on tree mechanical stability. The influence of leaf area and crown dynamics to tree growth was investigated by testing the interdependence between leaf area, branch, and stem growth on young loblolly pine trees. The objectives were to (1) determine the influence of current and previous year’s leaf area on elongation of branches; (2) describe and test a unique way of quantitatively measuring the effect of neighbor branches on net growth of a target branch; (3) quantify the growth impact of …

Go to article

First Prev Next Last