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Articles 2281 - 2310 of 3417
Full-Text Articles in Physical Sciences and Mathematics
Primes Of The Form X² + Ny² In Function Fields, Piotr Maciak
Primes Of The Form X² + Ny² In Function Fields, Piotr Maciak
LSU Doctoral Dissertations
Let n be a square-free polynomial over F_q, where q is an odd prime power. In this work, we determine which irreducible polynomials p in F_q[x] can be represented in the form X^2+nY^2 with X, Y in F_q[x]. We restrict ourselves to the case where X^2+nY^2 is anisotropic at infinity. As in the classical case over Z, the representability of p by the quadratic form X^2+nY^2 is governed by conditions coming from class field theory. A necessary and almost sufficient condition is that the ideal generated by p splits completely in the Hilbert class field H of K=F_q(x,sqrt(-n)) for the …
Computer Simulation Of Ion-Induced Nucleation In The Presence Of Single Ions And Ion Pairs, Samuel Keasler
Computer Simulation Of Ion-Induced Nucleation In The Presence Of Single Ions And Ion Pairs, Samuel Keasler
LSU Doctoral Dissertations
Atmospheric aerosol particles play an important role in climate and human health. Despite their importance, the mechanisms of their formation are still poorly understood. Ion-induced nucleation may play a role in the process, but details are lacking about how the nucleation rate depends on the size, charge, and number of ions in the cluster. In order to better understand the role that ions might play in new particle formation, we have performed a series of AVUS-HR simulations of the water nucleation in the presence of both single ions and ion pairs. These simulations have shown that the location of the …
Investigations Of Structure / Property Interrelationships Of Organic Thin Films Using Scanning Probe Microscopy And Nanolithography, Zorabel Mallorca Lejeune
Investigations Of Structure / Property Interrelationships Of Organic Thin Films Using Scanning Probe Microscopy And Nanolithography, Zorabel Mallorca Lejeune
LSU Doctoral Dissertations
Studies of the surface assembly and molecular organization of organic thin films were studied using scanning probe microscopy (SPM) and scanning probe lithography (SPL). Systems of organic thin films such as n-alkanethiols and pyridyl functionalized porphyrins were characterized at the molecular level, and measurements of the conductive properties of polythiophenes containing in-chain cobaltabisdicarbollides were accomplished. Understanding the self-organization and mechanisms of self-assembly of organic molecules provides fundamental insight for structure/property interrelationships. Investigations of the surface assembly of 5,10-diphenyl-15,20-di-pyridin-4-yl-porphyrin (DPP) on Au(111) were done using SPL methods of nanoshaving and nanografting. Automated computer designs were developed for nanofabrication to provide local …
Modeling The Impacts Of Pulsed Riverine Inflows On Hydrodynamics And Water Quality In The Barataria Bay Estuary, Anindita Das
Modeling The Impacts Of Pulsed Riverine Inflows On Hydrodynamics And Water Quality In The Barataria Bay Estuary, Anindita Das
LSU Doctoral Dissertations
Eutrophication and coastal wetland loss are the major environmental problems affecting estuaries around the world. In Louisiana, controlled diversions of the Mississippi River water back into coastal wetlands are thought to be an important engineering solution that could reverse coastal land loss. There are concerns, however, that freshwater diversions may increase nutrient inputs and create severe eutrophication problems in estuaries and wetlands adjacent to the diversion sites. My dissertation research concerns modeling the effects of the observed and hypothetical freshwater diversion discharges on the hydrodynamics, salinity and water quality in the Barataria estuary, a deltaic estuary in south Louisiana. This …
Studies Of Nanoparticles From A Group Of Uniform Materials Based On Organic Salts (Gumbos), Aaron Tesfai
Studies Of Nanoparticles From A Group Of Uniform Materials Based On Organic Salts (Gumbos), Aaron Tesfai
LSU Doctoral Dissertations
Tesfai, Aaron, B.S., B.A., University of Missouri, Columbia, 2003 Doctor of Philosophy, Spring Commencement 2010 Major: Chemistry Studies of Nanoparticles from a Group of Uniform Materials Based on Organic Salts (GUMBOS) Dissertation directed by Professor Isiah M. Warner Pages in dissertation, 101. Words in abstract, 271. Ionic liquids (ILs) are defined as organic salts composed of ions with melting points at or below 100 °C. ILs have gained considerable attention because of their desirable properties such as low volatility, high thermal stability, and tunability. GUMBOS are an emergent class of organic salts, many of which are ionic liquids (ILs). However, …
Application-Level Optimization Of End-To-End Data Transfer Throughput, Esma Yildirim
Application-Level Optimization Of End-To-End Data Transfer Throughput, Esma Yildirim
LSU Doctoral Dissertations
For large-scale distributed applications, effective use of available network throughput and optimization of data transfer speed is crucial for end-to-end application performance. Today, many regional and national optical networking initiatives such as LONI, ESnet and Teragrid provide high speed network connectivity to their users. However, majority of the users fail to obtain even a fraction of the theoretical speeds promised by these networks due to issues such as sub-optimal protocol tuning, disk bottleneck on the sending and/or receiving ends, and processor limitations. This implies that having high speed networks in place is important but not sufficient for the improvement of …
Early Life History Dynamics Of The Fish Community In The Atchafalaya River Basin, B. Thorpe Halloran
Early Life History Dynamics Of The Fish Community In The Atchafalaya River Basin, B. Thorpe Halloran
LSU Doctoral Dissertations
Seasonal overbank flooding in systems like the Atchafalaya River Basin (ARB) provides the opportunity for fishes in the mainstem to access off-channel areas on the floodplain. Typically, newly inundated floodplain habitats allow adult fishes to add biomass, avoid predation, and potentially, to reproduce. However, in systems like the ARB, the timing, duration, and magnitude of flooding infrequently coincides with known reproductive periods of many fishes assumed to be floodplain-dependent. To quantify the level of floodplain-exploitative fish reproduction in the ARB, I collected larval and juvenile fish with a variety of sampling gear that allowed estimates in both ultra-shallow (< 2-m) and continuously-inundated habitats (headwater lakes, canals, and bayous). A suite of water quality parameters, river stage, flow, and hours of daylight were used to gauge the influence of environmental phenomena on age-0 abundance during both inundation and drawdown. The results of the 19-month study suggest that many taxa do not rely on the floodplain to ensure high survivorship. Interestingly, the reproductive ecologies of many ARB fishes appeared to be largely independent of widespread connectivity. Although an increasing hydrograph appeared to enhance reproductive output, the interannual timing and intensity of spawning showed limited variability. Larval densities were also contrasted with the microcrustacean zooplankton (copepods and cladocerans) population to assess if a potential food limitation existed in the weeks and months following hatching. During the study, increased zooplankter abundance was typically preceded by elevated river-floodplain connectivity. Conversely, as floodwaters receded during the summer, zooplankton abundance declined to lowest levels observed during the study. Overall, there was limited synchronous overlap between the hatchlings of most fish taxa and their zooplankter prey. This could have potentially resulted in starvation and reduced annual recruitment. Yet, my analysis of the factors that regulate larval fish abundance in the ARB suggest that the density of zooplankton was highly significant although high numbers of larvae and zooplankton rarely coincided. Finally, I compared the intraday (morning vs. afternoon) density and mean length of larval fish at fixed sample sites. The results suggest that once-daily ichthyoplankton collections may fail to provide accurate density and length measurements for young fish populations.
Augmented Breast Tumor Classification By Perfusion Analysis, Bruce Yu-Sun Lin
Augmented Breast Tumor Classification By Perfusion Analysis, Bruce Yu-Sun Lin
LSU Doctoral Dissertations
Magnetic resonance and computed tomography imaging aid in the diagnosis and analysis of pathologic conditions. Blood flow, or perfusion, through a region of tissue can be computed from a time series of contrast-enhanced images. Perfusion is an important set of physiological parameters that reflect angiogenesis. In cancer, heightened angiogenesis is a key process in the growth and spread of tumorous masses. An automatic classification technique using recovered perfusion may prove to be a highly accurate diagnostic tool. Such a classification system would supplement existing histopathological tests, and help physicians to choose the most optimal treatment protocol. Perfusion is obtained through …
Modeling Thermal Phenomena And Searching For New Thermally Induced Monitor Signals In Large Sale Gravitational Wave Detectors, Rupal Shashikant Amin
Modeling Thermal Phenomena And Searching For New Thermally Induced Monitor Signals In Large Sale Gravitational Wave Detectors, Rupal Shashikant Amin
LSU Doctoral Dissertations
The Laser Interferometer Gravitational-wave Observatory (LIGO) array’s 4 km detectors have transitioned from an initial configuration (iLIGO) to an enhanced configuration (eLIGO) [1]. Both configurations relied on high circulating laser powers to achieve sensitivity goals between 150 Hz and 8 kHz. These power levels were sufficient to induce thermally driven focal affects in the primary optics. Since the detectors were designed to achieve maximum sensitivity when laser light was optimally coupled (mode matched) into the antenna, small deviations in focal parameters influenced performance. A laser based thermal compensation system (TCS) was installed for use in both configurations to counteract excessive …
Choosing Between Remote I/O Versus Staging In Distributed Environments, Ibrahim Hakki Suslu
Choosing Between Remote I/O Versus Staging In Distributed Environments, Ibrahim Hakki Suslu
LSU Doctoral Dissertations
Today, scientifi_x000C_c applications and experiments have become increasingly complex and more demanding in terms of their computational and data requirements. The amount of data generated and used has grown at a very rapid rate. As tens or hundreds of terabytes of data for a single application is very common today; petabytes and even exabytes of data will be very common in a few years. One of the major challenges in distributed computing environments is how to access these large datasets remotely over the network. Data staging and remote I/O are the most widely used data access methods for distributed applications. …
Upland Nesting Waterfowl Population Responses To Predator Reduction In North Dakota, Matthew R. Pieron
Upland Nesting Waterfowl Population Responses To Predator Reduction In North Dakota, Matthew R. Pieron
LSU Doctoral Dissertations
Population growth for mallards (Anas platyrhynchos), and presumably other upland nesting ducks, in the Prairie Pothole Region is most sensitive to nest success, and nest success is most strongly influenced by predation. I evaluated the efficacy of reducing predator populations to improve nest success and increase local breeding populations of upland nesting ducks on township-sized (93.2 km2) management units in eastern North Dakota, USA, during 2005−2008. I also examined potential territorial limitations on local population growth for mallards. Trappers annually removed an average of 245 predators per trapped site. I monitored 7,489 nests on 7 trapped and 5 nontrapped sites, …
The Effects Of A Freshwater Diversion Of Nekton Species Biomass Distributions, Food Web Pathways, And Community Structure In A Louisiana Estuary, Kim De Mutsert
The Effects Of A Freshwater Diversion Of Nekton Species Biomass Distributions, Food Web Pathways, And Community Structure In A Louisiana Estuary, Kim De Mutsert
LSU Doctoral Dissertations
A current method to restore Louisiana’s estuaries includes reintroducing freshwater and sediments to wetlands that are hydrologically isolated from the Mississippi River due to the construction of levees. In this dissertation, I examined effects of the second largest freshwater diversion in Louisiana, the Caernarvon Freshwater Diversion (CFD), on estuarine nekton in Breton Sound. Before focusing on Breton Sound, I examined the status of nekton communities in the northern Gulf of Mexico (GOM), and Louisiana wetlands in particular, using the mean trophic level index (MTLI). I demonstrated that commercial targeting caused the previously reported low and declining MTLI from the GOM. …
Design And Development Of Chiral And Achiral Molecularly Imprinted Stationary Phases, Jason Paul Lejeune
Design And Development Of Chiral And Achiral Molecularly Imprinted Stationary Phases, Jason Paul Lejeune
LSU Doctoral Dissertations
Although the cross-linker can comprise over 80% of the polymer composition, improving the nature of the cross-linker in molecularly imprinted polymers has not been studied extensively. The goal of this research is to develop novel cross-linking monomers to either use in the One MoNomer Molecularly Imprinted Polymer system (OMNiMIP) or use in conjunction with other commercially available cross-linkers and functional monomers. Chapter 2 contains research into the understanding of the performance of a new cross-linking monomer (N, O - bismethacryloyl ethanolamine, NOBE) discovered in the Spivak Research Group. The ability of this monomer to outperform traditional two monomer systems in …
Sample Properties Of Random Fields. Ii. Continuity, Jürgen Potthoff
Sample Properties Of Random Fields. Ii. Continuity, Jürgen Potthoff
Communications on Stochastic Analysis
No abstract provided.
On The Extension Of A Basic Property Of Conditional Expectations To Second Quantization Operators, Alberto Lanconelli
On The Extension Of A Basic Property Of Conditional Expectations To Second Quantization Operators, Alberto Lanconelli
Communications on Stochastic Analysis
No abstract provided.
Irreducible And Periodic Positive Maps, Franco Fagnola, Rely Pellicer
Irreducible And Periodic Positive Maps, Franco Fagnola, Rely Pellicer
Communications on Stochastic Analysis
No abstract provided.
Converse Comparison Theorems For Backward Doubly Stochastic Differential Equations, Mohamed El Otmani, Naoual Mrhardy
Converse Comparison Theorems For Backward Doubly Stochastic Differential Equations, Mohamed El Otmani, Naoual Mrhardy
Communications on Stochastic Analysis
No abstract provided.
Nonlinear Filtering Of Itô-Lévy Stochastic Differential Equations With Continuous Observations, S Popa, S S Sritharan
Nonlinear Filtering Of Itô-Lévy Stochastic Differential Equations With Continuous Observations, S Popa, S S Sritharan
Communications on Stochastic Analysis
No abstract provided.
Stochastic Integral Characterizations Of Semi-Selfdecomposable Distributions And Related Ornstein-Uhlenbeck Type Processes, Makoto Maejima, Yohei Ueda
Stochastic Integral Characterizations Of Semi-Selfdecomposable Distributions And Related Ornstein-Uhlenbeck Type Processes, Makoto Maejima, Yohei Ueda
Communications on Stochastic Analysis
No abstract provided.
Mrm-Applicable Orthogonal Polynomials For Certain Hypergeometric Functions, Izumi Kubo, Hui-Hsiung Kuo
Mrm-Applicable Orthogonal Polynomials For Certain Hypergeometric Functions, Izumi Kubo, Hui-Hsiung Kuo
Communications on Stochastic Analysis
No abstract provided.
Invariant States For The Asymmetric Exclusion Quantum Markov Semigroup, Julio C Garcia, Leopoldo Pantaleón-Martinez, Roberto Quezada
Invariant States For The Asymmetric Exclusion Quantum Markov Semigroup, Julio C Garcia, Leopoldo Pantaleón-Martinez, Roberto Quezada
Communications on Stochastic Analysis
No abstract provided.
Exact Scenario Simulation For Selected Multi-Dimensional Stochastic Processes, Eckhard Platen, Renata Rendek
Exact Scenario Simulation For Selected Multi-Dimensional Stochastic Processes, Eckhard Platen, Renata Rendek
Communications on Stochastic Analysis
No abstract provided.
Doubt And The Values Of An Ignorance-Based World View For Restoration: Coastal Louisiana Wetlands, R. Eugene Turner
Doubt And The Values Of An Ignorance-Based World View For Restoration: Coastal Louisiana Wetlands, R. Eugene Turner
Faculty Publications
Embracing doubt, a signature strength of science, is an essential core component of an ignorance-based-world view (IBWV) that assumes the areas of certainty are small relative to the large field of ignorance. The contrasting knowledge-based world view (KBWV) assumes that small and mostly insignificant knowledge gaps exist. When the KBWV is combined with a sense of urgency to “do something,” then the intellectual landscape is flattened, the introduction of new ideas is impeded, monitoring and adaptive management is marginalized, risky behaviors continue, and social learning is restricted. The history of three coastal Louisiana land-uses (agricultural impoundment, marsh management, and dredging) …
Generalized Cauchy-Stieltjes Transforms Of Some Beta Distributions, Nizar Demni
Generalized Cauchy-Stieltjes Transforms Of Some Beta Distributions, Nizar Demni
Communications on Stochastic Analysis
No abstract provided.
Using Weights For The Description Of States Of Boson Systems, Volkmar Liebscher
Using Weights For The Description Of States Of Boson Systems, Volkmar Liebscher
Communications on Stochastic Analysis
No abstract provided.
Markovian Systems Of Transition Expectations, Volkmar Liebscher, Michael Skeide
Markovian Systems Of Transition Expectations, Volkmar Liebscher, Michael Skeide
Communications on Stochastic Analysis
No abstract provided.
Local Time For Gaussian Processes As An Element Of Sobolev Space, Alexey Rudenko
Local Time For Gaussian Processes As An Element Of Sobolev Space, Alexey Rudenko
Communications on Stochastic Analysis
No abstract provided.
Generating Functions Of Jacobi Polynomials, Izumi Kubo
Generating Functions Of Jacobi Polynomials, Izumi Kubo
Communications on Stochastic Analysis
No abstract provided.
Unbounded Positive Solutions Of Nonlinear Parabolic Itô Equations, Pao-Liu Chow
Unbounded Positive Solutions Of Nonlinear Parabolic Itô Equations, Pao-Liu Chow
Communications on Stochastic Analysis
No abstract provided.
Representations Of The Gegenbauer Oscillator Algebra And The Overcompleteness Of Sequences Of Nonlinear Coherent States, Abdessatar Barhoumi
Representations Of The Gegenbauer Oscillator Algebra And The Overcompleteness Of Sequences Of Nonlinear Coherent States, Abdessatar Barhoumi
Communications on Stochastic Analysis
No abstract provided.