Digital Commons Network^™

Towards A Splitter Theorem For Internally 4-Connected Binary Matroids Vii, Carolyn Chun, James Oxley

Faculty Publications

Let M be a 3-connected binary matroid; M is internally 4-connected if one side of every 3-separation is a triangle or a triad, and M is (4,4,S)-connected if one side of every 3-separation is a triangle, a triad, or a 4-element fan. Assume M is internally 4-connected and that neither M nor its dual is a cubic Möbius or planar ladder or a certain coextension thereof. Let N be an internally 4-connected proper minor of M. Our aim is to show that M has a proper internally 4-connected minor with an N-minor that can be obtained from M either by …

Regularity Of The Local Time Of Diffusions On The Positive Real Line With Reflection At Zero, Masafumi Hayashi

Communications on Stochastic Analysis

No abstract provided.

On The Spectrum Of Self-Adjoint Lévy Generators, David Applebaum

Communications on Stochastic Analysis

No abstract provided.

On A Stochastic 2d Cahn-Hilliard-Navier-Stokes System Driven By Jump Noise, G. Deugoué, T. Tachim Medjo

Communications on Stochastic Analysis

No abstract provided.

Some Properties Of The Inhomogeneous Panjer Process, Ana María Beltrán Cortés, José Alfredo Jiménez Moscoso

Communications on Stochastic Analysis

No abstract provided.

Second Order Stochastic Partial Integro Differential Equations With Delay And Impulses, M.V.S.S.B.B.K. Sastry, G.V.S.R. Deekshitulu

Communications on Stochastic Analysis

No abstract provided.

Robust Resource Allocation With Imperfect Channel Estimation In Noma-Based Heterogeneous Vehicular Networks, Shengjie Guo, Xiangwei Zhou

Faculty Publications

In heterogeneous vehicular networks, non-orthogonal multiple access (NOMA) with effective resource allocation improves spectrum efficiency by allowing multiple users to share the same channel. However, channel estimation errors caused by high mobility in vehicular networks affect system robustness and link reliability. As a result, resource allocation in high-mobility scenarios is a challenging issue. In this paper, robust resource allocation is studied to improve both the throughput performance and reliability of NOMA-based heterogeneous vehicular networks. A cascaded Hungarian channel assignment algorithm is proposed to simplify the formulated resource allocation problem with reliability requirements into a robust power allocation problem with chance …

Voc Emission Factors From 3d Printers - Abs (Acrylonitrile-Butadiene-Styrene) Type Filaments, Dean Lay

LSU Master's Theses

Acrylonitrile-butadiene-styrene (ABS) is a polymer that is widely used in many plastic products and is receiving new attention due to its use as a filament for fused deposition modelling (FDM) 3D printers. It has been shown to emit potentially dangerous volatile organic compounds (VOCs) when heated at temperatures used in the 3D printing process. Many new products are becoming available that contain various additives to the polymer matrix, which have an unknown effect on the emission profiles and rates. In this study a method is developed using a modified system for thermal diagnostic studies (STDS) to evaluate VOC emission from …

Evaluation Of Naturally Occurring Radioactive Material In Seafood From The Gulf Of Mexico, Charles Algeo Wilson Iv

LSU Doctoral Dissertations

Radioactive disintegration of naturally occurring radioactive material was modeled with high precision and no assumptions to better understand serial decay in high order disequibrlia. This model helped develop a new method of quick analysis of NORM, where radioactivity can be measured with reasonable certainty before secular equilibrium is established. This approach was a significant improvement on previous similar approaches, halving time required for the same results and reduced wait time compared to classical approaches by 92%. Consequentially, NORM was measured in selected seafood samples from three areas in the Gulf of Mexico. Red Snapper, Red Drum, Northern Whiting, Spotted Trout …

Realization Of A Type-Ii Nodal-Line Semimetal In Mg3bi2, Weiwei Xie

Faculty Publications

Nodal-line semimetals (NLSs) represent a new type of topological semimetallic phase beyond Weyl and Dirac semimetals in the sense that they host closed loops or open curves of band degeneracies in the Brillouin zone. Parallel to the classification of type-I and type-II Weyl semimetals, there are two types of NLSs. The type-I NLS phase has been proposed and realized in many compounds, whereas the exotic type-II NLS phase that strongly violates Lorentz symmetry has remained elusive. First-principles calculations show that Mg3Bi2 is a material candidate for the type-II NLS. The band crossing is close to the Fermi level and exhibits …

Constraining The P-Mode-G-Mode Tidal Instability With Gw170817, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya

Faculty Publications

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: An overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB!pgpg) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform …

In Situ Geochemistry Of Middle Ordovician Dolomites Of The Upper Mississippi Valley, Achim D. Herrmann

Faculty Publications

The dolomitization and diagenetic history of Ordovician carbonates of southern Wisconsin is complex. Previous studies attributed dolomitization to various diagenetic factors and environments. In this study, high-resolution, in situ laser ablation inductively coupled mass spectrometry analysis of rare earth element patterns of dolomite was used to assess the diagenetic fluids responsible for dolomitization of the Ordovician Decorah Formation. Integrated geochemical data and petrographic evidence suggest that the dolostones are formed in two different diagenetic realms: shallow burial and hydrothermal. Shallow burial dolomites exhibit three distinct rare earth element patterns. Dolomite from the middle portion of the Guttenberg Member exhibits light …

Surface Coupling Of Octaethylporphyrin With Silicon Tetrachloride, Jayne C. Garno, Phillip C. Chambers, Neepa M. K. Kuruppu Arachchige, Ashley M. Taylor

Faculty Publications

The surface assembly of 2,3,7,8,12,13,17,18-octaethylporphyrin (OEP) using silicon tetrachloride as a coupling agent was investigated using atomic force microscopy (AFM). Nanopatterned films of Si-OEP were prepared by protocols of colloidal lithography to evaluate the morphology, thickness, and molecular orientation for samples prepared on Si(111). The natural self-stacking of porphyrins can pose a challenge for molecular patterning. When making films on surfaces, porphyrins will self-associate to form co-planar configurations of random stacks of molecules. There is a tendency for the flat molecules to orient spontaneously in a side-on arrangement that is mediated by physisorption to the substrate as well as by …

Factors Affecting Growth Kinetics And Spontaneous Metastasis In The B16f10 Syngeneic Murine Melanoma Model, Natalie Fowlkes, Kelli Clemons, Paul Jf Rider, Ramesh Subramanian, Nobuko Wakamatsu, Ingeborg Langohr, Konstantin G. Kousoulas

Faculty Publications

Melanoma is an immunogenic tumor that can metastasize quickly to proximal and distal sites, thus complicating the application of therapeutic modalities. Numerous mouse model systems have been used to gain understanding of the immunobiology and metastatic potential of melanoma. Here, we report the optimization of a syngeneic mouse melanoma model protocol using the mouse B16-derived melanoma cell line B16F10 that ensures the production of tumors on mice pinnae that are similar in size between animals and that enlarge in a time-dependent manner. In this model, B16F10 cells are first allowed to develop tumors after injection in the interscapular area or …

In Situ Geochemistry Of Middle Ordovician Dolomites Of The Upper Mississippi Valley, Achim D. Herrmann

Faculty Publications

The dolomitization and diagenetic history of Ordovician carbonates of southern Wisconsin is complex. Previous studies attributed dolomitization to various diagenetic factors and environments. In this study, high-resolution, in situ laser ablation inductively coupled mass spectrometry analysis of rare earth element patterns of dolomite was used to assess the diagenetic fluids responsible for dolomitization of the Ordovician Decorah Formation. Integrated geochemical data and petrographic evidence suggest that the dolostones are formed in two different diagenetic realms: shallow burial and hydrothermal. Shallow burial dolomites exhibit three distinct rare earth element patterns. Dolomite from the middle portion of the Guttenberg Member exhibits light …

Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Terrebonne And Timbalier Bays, Louisiana, Mary Allison Manning

LSU Master's Theses

I coupled fine-scale environmental data with observed behavior and group composition data to examine overall distribution within the bay system and to characterize the habitat associated with foraging and the presence of calves. Semi-isolated populations of bottlenose dolphins (Tursiops truncatus) along Louisiana’s coast are undergoing increased risks from boat traffic, oil spills, land subsidence, and planned water diversions (CPRA 2017). Characterizing the habitat use of bottlenose dolphins in Terrebonne and Timbalier bays, Louisiana, is important given the likely high site fidelity, small home ranges, and low exchange of individuals with nearby coastal populations (Lane et al. 2015, McDonald …

Downscaling Smap Soil Moisture Data Using Modis Data, Le Tu

LSU Master's Theses

Soil moisture level is an important index in studying environmental changes. High resolution soil moisture data is in high demand for agricultural and weather forecasting purpose. Current daily large-scale soil moisture projects fail to provide sufficient resolution for medium or small region research. To acquire high-resolution soil moisture data, different kinds of methods are put into practice, including multivariate statistical regression, weight aggregation and so on. In this research, SMAP (Soil Moisture Active Passive) level 3 data with 36-km resolution are successfully downscaled by MODIS (Moderate Resolution Imaging Spectroradiometer) 1-km LST (Land Surface Temperature) product, NDVI (Difference Vegetation Index) product, …

An Experimental Study Of Fractional Wettability Effects On Gas Assisted Gravity Drainage (Gagd), Abdullah Abdulrahman A. Al-Tameemi

LSU Master's Theses

Utilizing the power of nature to solve engineering problems has been a time-honored tradition, for example, using the sunlight as a heat and light source. From this principle, the visionary idea of Gas Assisted Gravity Drainage (GAGD) came. The GAGD process utilizes the natural segregation phenomenon of fluids with different densities in order to produce oil efficiently and economically. Waterflooding processes typically do not recover more than 40% of the original oil in place (OOIP), leaving a vast amount of oil behind. A practical and well-planned enhanced oil recovery (EOR) method is needed. However, to plan a successful project, the …

Low-Density Static Granular Media Filter Bed Turbidity Removal Model, Matthew Louque

LSU Master's Theses

The scattering of light within a fluid, referred to as its turbidity, was investigated against the presence of suspended solids. A linear regression analysis was conduced against turbidity and the total count, combined surface area, and combined volume of the suspended particles for various surface water sources (lakes, rivers, indoor aquaculture systems). It was found that the total combined surface area of suspended particles had the best linear correlation to turbidity, with an adjusted R² of 81.79%. This correlation was integrated with a current theoretical model for predicting solids removal across a granular bed to yield an Integrated Turbidity …

Monitoring Sediment Dynamics And Vegetation Competition Based On Micro-Topography And Terrestrial Lidar For Wetland Restoration, Xukai Zhang

LSU Doctoral Dissertations

With the ability to attenuate wave and limit erosion, coastal wetlands are important to protect shoreline for coastal communities. Micro-topography in coastal wetlands has a significant influence on hydrology, habitat variability and ecosystem functions. However, when mapping micro-topography by terrestrial LiDAR in coastal environments, the coverage of dense vegetation leads to a relatively low chance of laser penetration through the canopy to the ground. This dissertation proposes a rapid and flexible terrain mapping solution for the densely vegetated coastal environment by integrating crown structure from terrestrial LiDAR with terrain samples from GPS. The validated results in the study site demonstrate …

Immobilization Adjusted Clock Reaction In The Urea-Urease-H+ Reaction System, John A. Pojman

Faculty Publications

The bell-shaped reactivity-pH curve is the fundamental reason that the temporal programmable kinetic switch in clock reactions can be obtained in bio-competitive enzymatic reactions. In this work, urease was loaded on small resin particles through ionic binding. Experimental results reveal that the immobilization not only increased the stability of the enzyme and the reproducibility of the clock reaction, but also shifted the bell-shaped activity curve to lower pHs. The latter change enables the clock reaction to occur from an initial pH of 2.3, where the free enzyme had already lost its activity. Two mechanisms explain the influence of the immobilization …

Predictability Of Ocean Heat Content From Electrical Conductance, D. S. Trossman, R. H. Tyler

Faculty Publications

No abstract provided.

Short Communication: The Topographic Analysis Kit (Tak) For Topotoolbox, Adam M. Fortes

Faculty Publications

Quantitative analysis of digital topographic data is an increasingly important part of many studies in the geosciences. Initially, performing these analyses was a niche endeavor, requiring detailed domain knowledge and programming skills, but increasingly broad, flexible, open-source code bases have been developed to increasingly democratize topographic analysis. However, many of these analyses still require specific computing environments and/or moderate levels of knowledge of both the relevant programming language and the correct way to take these fundamental building blocks and conduct an efficient and effective topographic analysis. To partially address this, we have written the Topographic Analysis Kit (TAK), which leverages …

Reduced Order Finite Time Observers For Time-Varying Nonlinear Systems, Frederic Mazenc, Saeed Ahmed, Michael Malisoff

Faculty Publications

We build reduced order finite time observers for a large class of nonlinear time-varying continuous-time systems. We illustrate our results using a tracking problem for nonholonomic systems in chained form.

Sequential Predictors For Linear Time-Varying Systems With Delays In The Vector Field And In The Input, Michael Malisoff, Frederic Mazenc

Faculty Publications

We provide new sequential predictors for a large class of linear time-varying systems that contain constant delays in the vector fields and also constant delays in the inputs. We allow the input delays to be arbitrarily large. We prove global exponential stability of the origin for an augmented system that includes the original system in closed loop with our sequential predictors based feedback control. We illustrate our new theorem in an example from identification theory.

Predicting High-Dimensional Isotope Relationships From Diagnostic Fractionation Factors In Systems With Diffusional Mass Transfer, Yuyang He, Huiming Bao

Faculty Publications

© 2018 American Chemical Society. A dual or multiple stable isotope relationship, for example, a trajectory in a δ-δ (or δ′-δ′) space, can be used to deduce the relationship of underlying diagnostic isotope fractionation factors (α) and therefore reveal the mechanism of a reaction process. While temporal data sampled from a closed-system can be treated by a Rayleigh distillation model, spatial data should be treated by a reaction-transport model. Owing to an apparent similarity between the temporal and spatial trajectories, the research community has often ignored this distinction and applied a Rayleigh distillation model to cases where a reaction-transport model …

Predicting High-Dimensional Isotope Relationships From Diagnostic Fractionation Factors In Systems With Diffusional Mass Transfer, Yuyang He, Huiming Bao

Faculty Publications

© 2018 American Chemical Society. A dual or multiple stable isotope relationship, for example, a trajectory in a δ-δ (or δ′-δ′) space, can be used to deduce the relationship of underlying diagnostic isotope fractionation factors (α) and therefore reveal the mechanism of a reaction process. While temporal data sampled from a closed-system can be treated by a Rayleigh distillation model, spatial data should be treated by a reaction-transport model. Owing to an apparent similarity between the temporal and spatial trajectories, the research community has often ignored this distinction and applied a Rayleigh distillation model to cases where a reaction-transport model …

Wavepy - Python Package For X-Ray Grating Interferometry With Applications In Imaging And Wavefront Characterization, Walan Grizolli, Xianbo Shi, Lahsen Assoufid, Leslie G. Butler

Faculty Publications

© 2019 Author(s). X-ray grating interferometry has been employed for a wide range of imaging applications by using the Talbot self-images of a grating. At synchrotron facilities, it has also been exploited to characterize the coherence and wavefront of the x-ray beam. The method is relatively straightforward, easy to implement, and provides accurate quantitative data. However, to exploit its full potential, it requires highly specialized, robust data analysis. It this work, we have set the framework for the development and dissemination of a robust open-source code that is tailored to the data analysis for imaging and beam characterization using grating …

Ignition And Extinction Behavior Of Fuels In A Microcombustor, Pawan Sharma

LSU Doctoral Dissertations

Conventional fuel testing device-CFR engine requires large quantities of fuels, which makes it unsuitable for research of small samples of fuels. This current study seeks to address this limitation by using an externally heated microcombustor as an alternative fuel testing device. Mainly three combustion behaviors have been observed inside a microcombustor: strong flames at higher flow rates, Flames with Repetitive Extinction and Ignition (FREI) at intermediate flow rates, and weak flames at marginal flow rates. In previous studies, weak combustion behavior has been proven suitable to study fuel properties from small samples of fuels. Microcombustor experiments typically rely on flame …

An Airlifted Tidal Mesocosm For Oil Degradation Studies, Daniel Christopher Alt

LSU Doctoral Dissertations

Mesocosms were constructed to allow scientists to isolate variables in a microtidal marsh environment, mimicking the natural conditions found in Terrebonne Bay. The control offered by these mesocosms is given by a process control system that takes user inputs and automates water movement. Twelve mesocosms were constructed, each holding 4.02 m³ (142 ft³) of marsh soil and 3.88 m³ (137 ft³) of water to give 3 experimental levels and a control, all in triplicate.

Each mesocosms that was constructed contained marsh plants in soil plugs 9 feet in diameter and 3 feet deep. These …