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

Digital Commons Network™

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

Louisiana State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 10351 - 10380 of 45179

Full-Text Articles in Entire DC Network

The Comparative Genomics And Complex Population History Of Papio Baboons, Jeffrey Rogers, Muthuswamy Raveendran, R. Alan Harris, Thomas Mailund, Kalle Leppälä, Georgios Athanasiadis, Mikkel Heide Schierup, Jade Cheng, Kasper Munch, Jerilyn A. Walker, Miriam K. Konkel, Vallmer E. Jordan, Cody J. Steely, Thomas O. Beckstrom, Christina Bergey, Andrew Burrell, Dominik Schrempf, Angela Noll, Maximillian Kothe, Gisela H. Kopp, Yue Liu, Shwetha Murali, Konstantinos Billis, Fergal J. Martin, Matthieu Muffato, Laura A. Cox, James Else, Todd Disotell, Donna M. Muzny, Jane Phillips-Conroy, Bronwen Aken, Evan E. Eichler, Tomas Marques-Bonet, Carolin Kosiol Jan 2019

The Comparative Genomics And Complex Population History Of Papio Baboons, Jeffrey Rogers, Muthuswamy Raveendran, R. Alan Harris, Thomas Mailund, Kalle Leppälä, Georgios Athanasiadis, Mikkel Heide Schierup, Jade Cheng, Kasper Munch, Jerilyn A. Walker, Miriam K. Konkel, Vallmer E. Jordan, Cody J. Steely, Thomas O. Beckstrom, Christina Bergey, Andrew Burrell, Dominik Schrempf, Angela Noll, Maximillian Kothe, Gisela H. Kopp, Yue Liu, Shwetha Murali, Konstantinos Billis, Fergal J. Martin, Matthieu Muffato, Laura A. Cox, James Else, Todd Disotell, Donna M. Muzny, Jane Phillips-Conroy, Bronwen Aken, Evan E. Eichler, Tomas Marques-Bonet, Carolin Kosiol

Faculty Publications

Copyright © 2019 The Authors, Recent studies suggest that closely related species can accumulate substantial genetic and phenotypic differences despite ongoing gene flow, thus challenging traditional ideas regarding the genetics of speciation. Baboons (genus Papio) are Old World monkeys consisting of six readily distinguishable species. Baboon species hybridize in the wild, and prior data imply a complex history of differentiation and introgression. We produced a reference genome assembly for the olive baboon (Papio anubis) and whole-genome sequence data for all six extant species. We document multiple episodes of admixture and introgression during the radiation of Papio baboons, thus demonstrating their …


Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Terrebonne And Timbalier Bays, Louisiana, Mary Allison Manning Jan 2019

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 Jan 2019

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 Jan 2019

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 Jan 2019

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 …


Effects Of Red Raspberry Polyphenols And Metabolites On Biomarkers Of Inflammation And Insulin Resistance In Prediabetes And Type 2 Diabetes, Reynaldo Moreno Ucles Jan 2019

Effects Of Red Raspberry Polyphenols And Metabolites On Biomarkers Of Inflammation And Insulin Resistance In Prediabetes And Type 2 Diabetes, Reynaldo Moreno Ucles

LSU Doctoral Dissertations

Berry fruits are rich sources of polyphenolic compounds (PCs), which can promote health benefits. Anthocyanin concentrations of red raspberry (RR)(Rubus idaeus) extracts were determined to be a total of 887.6 ± 262.8 μg/g cyanidin-3-sophoroside (C3S) equivalents with C3S being the most prevalent. Ellagitannin analysis by MALDI-TOF indicated sanguiin H-6 and lambertianin C were the major ellagitannins present in RR. To explore the efficacy of RR in modulating diabetes, seven type 2 diabetes mellitus (T2DM) and two pre-diabetic patients were given drinks delivering one RR serving (123 g) per day in a smoothie for two weeks. Blood samples were …


Monitoring Sediment Dynamics And Vegetation Competition Based On Micro-Topography And Terrestrial Lidar For Wetland Restoration, Xukai Zhang Jan 2019

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 Jan 2019

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 …


Quantum Oscillations And A Nontrivial Berry Phase In The Noncentrosymmetric Topological Superconductor Candidate Bipd, Mojammel A. Khan, D. E. Graf, I. Vekhter, D. A. Browne, J. F. Ditusa, W. Adam Phelan, D. P. Young Jan 2019

Quantum Oscillations And A Nontrivial Berry Phase In The Noncentrosymmetric Topological Superconductor Candidate Bipd, Mojammel A. Khan, D. E. Graf, I. Vekhter, D. A. Browne, J. F. Ditusa, W. Adam Phelan, D. P. Young

Faculty Publications

We report the measurements of de Haas-van Alphen (dHvA) oscillations in the noncentrosymmetric superconductor BiPd. Several pieces of a complex multisheet Fermi surface are identified, including a small pocket (α∼40 T) which is three dimensional and anisotropic. From the temperature dependence of the amplitude of the oscillations, the cyclotron effective mass is (0.18±0.02) me. Further analysis revealed a nontrivial π-Berry phase is associated with the 40 T pocket, which strongly supports the presence of topological states in bulk BiPd.


Predictability Of Ocean Heat Content From Electrical Conductance, D. S. Trossman, R. H. Tyler Jan 2019

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

Faculty Publications

No abstract provided.


Unpinning The Skyrmion Lattice In Mnsi: Effect Of Substitutional Disorder, C. Dhital, L. Debeer-Schmitt, D. P. Young, J. F. Ditusa Jan 2019

Unpinning The Skyrmion Lattice In Mnsi: Effect Of Substitutional Disorder, C. Dhital, L. Debeer-Schmitt, D. P. Young, J. F. Ditusa

Faculty Publications

By employing magnetization and small angle neutron scattering measurements, we have investigated the behavior of the skyrmion lattice (SKL) and the helical order in MnSi0.992Ga0.008 Our results indicate that the order of the SKL is sensitive to the orientation of an applied magnetic field with respect to the crystal lattice and to variations in the sequence of small temperature and applied magnetic field changes. The disorder caused by the substitution of the heavier element Ga for Si is sufficient to reduce the pinning of the SKL to the underlying crystalline lattice, reducing the propensity for the SKL to be aligned …


Conditional Knock-Out Of Mglur5 From Astrocytes During Epilepsy Development Impairs High-Frequency Glutamate Uptake, Anthony D. Umpierre, Peter J. West, John A. White, Karen S. Wilcox Jan 2019

Conditional Knock-Out Of Mglur5 From Astrocytes During Epilepsy Development Impairs High-Frequency Glutamate Uptake, Anthony D. Umpierre, Peter J. West, John A. White, Karen S. Wilcox

Faculty Publications

No abstract provided.


Too Hot To Move: Temperatures During Transportation Might Reduce The Survival Of Salvinia Weevils (Coleoptera: Curculionidae), Lauren A. Cozad, Rodrigo Diaz, Christopher R. Mudge Jan 2019

Too Hot To Move: Temperatures During Transportation Might Reduce The Survival Of Salvinia Weevils (Coleoptera: Curculionidae), Lauren A. Cozad, Rodrigo Diaz, Christopher R. Mudge

Faculty Publications

© 2019 Florida Entomological Society. All rights reserved. The biological control agent, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) (salvinia weevil), is being used for management of the highly invasive fern Salvinia molesta Mitchell (Salvinaceae) in Louisiana and Texas, USA. The weevils and plants are transported from the nurseries and rearing facilities to the field release sites in plastic totes. Despite the increased transport of weevil-infested plants during the warmer months, limited data exist on the impact of heat stress and survivability of adult C. salviniae. Therefore, research was conducted to determine temperatures inside totes during summer transport, and to …


Impact Of Psychological And Physical Stressors On The Exercise-Induced Immune Response In Collegiate Swimmers, Connor Alexander Kuremsky Jan 2019

Impact Of Psychological And Physical Stressors On The Exercise-Induced Immune Response In Collegiate Swimmers, Connor Alexander Kuremsky

LSU Master's Theses

Evidence suggests high-intensity exercise training increases incidence of upper respiratory infection in young-adult athletes (Spence et al. 2007). Collegiate athletes experience chronic stress, which has been shown to result in increased proportions of late-differentiated CD8+ T-cells of a dysfunctional phenotype (Bosch et al. 2009). However, many studies fail to consider possible moderators such as psychological stress and cytomegalovirus (CMV) infection. Purpose: To examine the impact of psychological stress, CMV infection, and exercise on proportions of early- and late-differentiated CD4+ and CD8+ T-cells in collegiate swimmers over a 7-month training period. Methods: Data were collected from NCAA …


Short Communication: The Topographic Analysis Kit (Tak) For Topotoolbox, Adam M. Fortes Jan 2019

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 …


Modeling Of Leakage Through Fault-Zone Structures In Co2 Geological Storage, Dayna Rodriguez Zambrano Jan 2019

Modeling Of Leakage Through Fault-Zone Structures In Co2 Geological Storage, Dayna Rodriguez Zambrano

LSU Master's Theses

Faults intersecting target geological CO2 storage zones have important implications for storage integrity. Potential leakage pathways due to fluid over-pressurization are investigated in this project to ensure long-term containment of injected CO2. Numerical flow simulations coupled with a geomechanical module are presented in this work with the purpose of determining the extent of CO2 up-fault migration, the driving mechanisms of leakage and the corresponding response of quantified pore pressure and stress variations.

This study uses dual-continuum models performed by using CMG (2017) to correctly account of flow through fractures in a fault damage zone. Numerical simulations …


Optimization Of Photonic Nanojets Generated By Multilayer Microcylinders With A Genetic Algorithm, Yin Huang, Zhishen Zhen, Yuecheng Shen, Changjun Min, Georgios Veronis Jan 2019

Optimization Of Photonic Nanojets Generated By Multilayer Microcylinders With A Genetic Algorithm, Yin Huang, Zhishen Zhen, Yuecheng Shen, Changjun Min, Georgios Veronis

Faculty Publications

We employ a genetic algorithm coupled with Mie theory to optimize the magnetic field intensity profile of photonic nanojets (PNJs) generated by multilayer microcylinders at visible wavelengths in free space. We first optimize five-layer microcylinders to elongate the PNJs. We show that a properly designed five-layer microcylinder structure can generate an ultra-long PNJ with a beam length ∼ 107.5 times the illumination wavelength λ0. We then optimize five-layer microcylinders to narrow the waist of PNJs. We show that a PNJ with a full-width at half maximum waist of ∼ 0.22λ0 can be obtained outside the surface of the optimized microcylinder. …


A Fermi Gamma-Ray Burst Monitor Search For Electromagnetic Signals Coincident With Gravitational-Wave Candidates In Advanced Ligo's First Observing Run, E. Burns, A. Goldstein, C. M. Hui, L. Blackburn, M. S. Briggs, V. Connaughton, R. Hamburg, D. Kocevski, P. Veres, C. A. Wilson-Hodge, E. Bissaldi, W. H. Cleveland, M. M. Giles, B. Mailyan, C. A. Meegan, W. A. Paciesas, S. Poolakkil, R. D. Preece, J. L. Racusin, O. J. Roberts, A. Von Kienlin, 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 Jan 2019

A Fermi Gamma-Ray Burst Monitor Search For Electromagnetic Signals Coincident With Gravitational-Wave Candidates In Advanced Ligo's First Observing Run, E. Burns, A. Goldstein, C. M. Hui, L. Blackburn, M. S. Briggs, V. Connaughton, R. Hamburg, D. Kocevski, P. Veres, C. A. Wilson-Hodge, E. Bissaldi, W. H. Cleveland, M. M. Giles, B. Mailyan, C. A. Meegan, W. A. Paciesas, S. Poolakkil, R. D. Preece, J. L. Racusin, O. J. Roberts, A. Von Kienlin, 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

Faculty Publications

We present a search for prompt gamma-ray counterparts to compact binary coalescence gravitational wave (GW) candidates from Advanced LIGO's first observing run (O1). As demonstrated by the multimessenger observations of GW170817/GRB 170817A, electromagnetic and GW observations provide complementary information about the astrophysical source, and in the case of weaker candidates, may strengthen the case for an astrophysical origin. Here we investigate low-significance GW candidates from the O1 compact binary coalescence searches using the Fermi Gamma-Ray Burst Monitor (GBM), leveraging its all sky and broad energy coverage. Candidates are ranked and compared to background to measure the significance. Those with false …


Reduced Order Finite Time Observers For Time-Varying Nonlinear Systems, Frederic Mazenc, Saeed Ahmed, Michael Malisoff Jan 2019

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 Jan 2019

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.


Influence Of Nitrogen And Sprig Planting Rates On Surface Runoff Losses During 'Latitude 36' Bermudagrass Establishment, Lance A. Rice Jan 2019

Influence Of Nitrogen And Sprig Planting Rates On Surface Runoff Losses During 'Latitude 36' Bermudagrass Establishment, Lance A. Rice

LSU Master's Theses

The hybrid bermudagrass (Cynodon dactylon x C. transvaalensis) ‘Latitude 36’ is grown because of its quality, excellent wear tolerance and fast recuperation. Hybrid bermudagrasses are vegetatively propagated as sprigs with N applied to accelerate establishment. Since losses of soil and associated nutrients in runoff are relatively high when ground coverage is low, rapid establishment is desirable from an environmental besides aesthetic basis. However, neither the interactive effect of sprig density and N fertilization on the rate of bermudagrass expansion nor soil and nutrient loss during establishment has been carefully examined. The current work measured bermudagrass coverage, runoff volume …


Predicting High-Dimensional Isotope Relationships From Diagnostic Fractionation Factors In Systems With Diffusional Mass Transfer, Yuyang He, Huiming Bao Jan 2019

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 Jan 2019

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 …


The Genetic And Epigenetic Effects Of Pre-Treatment With The Small Molecule Inhibitors Chir99021, Pd0325901, And Nup0178 On Bovine Fetal Fibroblast Cells, Laura Whitney Coley Jan 2019

The Genetic And Epigenetic Effects Of Pre-Treatment With The Small Molecule Inhibitors Chir99021, Pd0325901, And Nup0178 On Bovine Fetal Fibroblast Cells, Laura Whitney Coley

LSU Doctoral Dissertations

The ability to produce genetically superior livestock has established somatic cell nuclear transfer (SCNT) as an invaluable tool in commercial livestock production. Successful reprogramming of somatic cells towards pluripotency requires the epigenetic marks characteristic of the differentiated cell type first be erased in order to inactivate the somatic cell program and activate the embryonic program. Several small molecules have been shown to improve both the kinetics and efficiency of reprogramming. These chemical modifiers aid in overcoming the “roadblocks” encountered during the reprogramming process by inducing the necessary epigenetic modifications needed to silence the somatic cell genome and completely reactivate the …


Analyzing Hermeto Pascoal's Calendário Do Som, Adam Rosado Jan 2019

Analyzing Hermeto Pascoal's Calendário Do Som, Adam Rosado

LSU Doctoral Dissertations

Hermeto Pascoal is one of the most prolific composers of the twentieth and twenty-first centuries, having composed thousands of pieces across his career. Despite his immense and eclectic catalogue, the current analytical literature on him is comparatively scant, particularly outside of the composer’s native Brazil. In order to represent the diversity of his music, this dissertation studies a collection of his works entitled the Calendário do Som. This collection was an exercise in daily composition and comprises 366 short pieces written from July 23, 1996 to July 23, 1997. Through the analysis of the pieces in this collection, this dissertation …


Nitrogen Content In The Earth's Outer Core, Suraj K. Bajgain, Mainak Mookherjee, Rajdeep Dasgupta, Dipta B. Ghosh, Bijaya B. Karki Jan 2019

Nitrogen Content In The Earth's Outer Core, Suraj K. Bajgain, Mainak Mookherjee, Rajdeep Dasgupta, Dipta B. Ghosh, Bijaya B. Karki

Faculty Publications

Using first principles molecular dynamic simulations, we explore the effects of nitrogen (N) on the density and sound velocity of liquid iron and evaluate its potential as a light element in the Earth's outer core. Our results suggest that Fe-N melt cannot simultaneously explain the density and seismic velocity of the Earth's outer core. Although ~2.0 wt.% N can explain the bulk sound velocity of the outer core, such N content only lowers the density of liquid Fe by ~3%. Matching both the velocity and density by the other light elements limits the N in the core to ≪2.0 wt.%. …


Quantification Of Swell Energy And Its Impact On Wetlands In A Deltaic Estuary, Thomas Everett, Qin Chen, Arash Karimpour, Robert Twilley Jan 2019

Quantification Of Swell Energy And Its Impact On Wetlands In A Deltaic Estuary, Thomas Everett, Qin Chen, Arash Karimpour, Robert Twilley

Faculty Publications

The extensive coastal wetlands in Mississippi River Delta represent the seventh largest deltaic floodplain in the world, contributing to many services that sustain the economies of the region. Subsidence, sea level rise, saltwater intrusion, wave action from storms, and sediment depletion have contributed to chronic wetland losses, converting vegetated lands into open waters and increasing wind fetch. Among these factors listed, wave energy plays the largest role in marsh edge erosion in an open bay environment. Degrading barrier islands along the shoreline of this delta allow swell energy to enter protected bay areas, contributing to marsh edge erosion. Locally generated …


Atomic Resolution Of Cotton Cellulose Structure Enabled By Dynamic Nuclear Polarization Solid-State Nmr, Alex Kirui, Zhe Ling, Xue Kang, Malitha C. Dickwella Widanage, Frederic Mentink-Vigier, Alfred D. French, Tuo Wang Jan 2019

Atomic Resolution Of Cotton Cellulose Structure Enabled By Dynamic Nuclear Polarization Solid-State Nmr, Alex Kirui, Zhe Ling, Xue Kang, Malitha C. Dickwella Widanage, Frederic Mentink-Vigier, Alfred D. French, Tuo Wang

Faculty Publications

© 2018, Springer Nature B.V. Abstract: The insufficient resolution of conventional methods has long limited the structural elucidation of cellulose and its derivatives, especially for those with relatively low crystallinities or in native cell walls. Recent 2D/3D solid-state NMR studies of 13 C uniformly labeled plant biomaterials have initiated a re-investigation of our existing knowledge in cellulose structure and its interactions with matrix polymers but for unlabeled materials, this spectroscopic method becomes impractical due to limitations in sensitivity. Here, we investigate the molecular structure of unlabeled cotton cellulose by combining natural abundance 13 C– 13 C 2D correlation solid-state NMR …


Effects Of Ball Milling On The Structure Of Cotton Cellulose, Zhe Ling, Tuo Wang, Mohamadamin Makarem, Michael Santiago Cintrón, H. N. Cheng, Xue Kang, Markus Bacher, Antje Potthast, Thomas Rosenau, Holly King, Christopher D. Delhom, Sunghyun Nam, J. Vincent Edwards, Seong H. Kim, Feng Xu, Alfred D. French Jan 2019

Effects Of Ball Milling On The Structure Of Cotton Cellulose, Zhe Ling, Tuo Wang, Mohamadamin Makarem, Michael Santiago Cintrón, H. N. Cheng, Xue Kang, Markus Bacher, Antje Potthast, Thomas Rosenau, Holly King, Christopher D. Delhom, Sunghyun Nam, J. Vincent Edwards, Seong H. Kim, Feng Xu, Alfred D. French

Faculty Publications

© 2019, This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply. Cellulose is often described as a mixture of crystalline and amorphous material. A large part of the general understanding of the chemical, biochemical and physical properties of cellulosic materials is thought to depend on the consequences of the ratio of these components. For example, amorphous materials are said to be more reactive and have less tensile strength but comprehensive understanding and definitive analysis remain elusive. Ball milling has been used for decades to increase the ratio of amorphous material. …


Wavepy - Python Package For X-Ray Grating Interferometry With Applications In Imaging And Wavefront Characterization, Walan Grizolli, Xianbo Shi, Lahsen Assoufid, Leslie G. Butler Jan 2019

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 …