Digital Commons Network^™

Studies Of X-Ray Burst Reactions With Radioactive Ion Beams From Resolut, J. C. Blackmon, I. Wiedenhöver, J. Belarge, S. A. Kuvin, M. Anastasiou, L. T. Baby, J. Baker, K. Colbert, C. M. Deibel, H. E. Gardiner, D. L. Gay, E. Good, P. Höflich, A. A.D. Hood, N. Keely, J. Lai, A. Laminack, L. E. Linhardt, J. Lighthall, K. T. Macon, E. Need, N. Quails, B. C. Rasco, N. Rijal, A. Volya

Faculty Publications

Reactions on certain proton-rich, radioactive nuclei have been shown to have a significant influence on X-ray bursts. We provide an overview of two recent measurements of important X-ray burst reactions using in-flight radioactive ion beams from the RESOLUT facility at the J. D. Fox Superconducting Accelerator Laboratory at Florida State University. The 17F(d,n)18Ne reaction was measured, and Asymptotic Normalization Coefficients were extracted for bound states in 18Ne that determine the direct-capture cross section dominating the 17F(p,γ)18Ne reaction rate for T ≲ 0.45 GK. Unbound resonant states were also studied, and the single-particle strength for the 4.523-MeV (3+) state was found …

X-Ray Burst Studies With The Jensa Gas Jet Target, Konrad Schmidt, Kelly A. Chipps, Sunghoon Ahn, Jacob M. Allen, Sara Ayoub, Daniel W. Bardayan, Jeffrey C. Blackmon, Drew Blankstein, Justin Browne, Soomi Cha, Kyung Yuk Chae, Jolie Cizewski, Catherine M. Deibel, Eric Deleeuw, Orlando Gomez, Uwe Greife, Ulrike Hager, Matthew R. Hall, Katherine L. Jones, Antonios Kontos, Raymond L. Kozub, Eunji Lee, Alex Lepailleur, Laura E. Linhardt, Milan Matos, Zach Meisel, Fernando Montes, Patrick D. O'Malley, Wei Jia Ong, Steven D. Pain, Alison Sachs, Hendrik Schatz, Kyle T. Schmitt

Faculty Publications

When a neutron star accretes hydrogen and helium from the outer layers of its companion star, thermonuclear burning enables the αp-process as a break out mechanism from the hot CNO cycle. Model calculations predict (α, p) reaction rates significantly affect both the light curves and elemental abundances in the burst ashes. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target enables the direct measurement of previously inaccessible (α,p) reactions with radioactive beams provided by the rare isotope re-accelerator ReA3 at the National Superconducting Cyclotron Laboratory (NSCL), USA. JENSA is going to be the main target for the …

Cross Section Measurements In The 12C+12C System, S. Courtin, C. L. Jiang, G. Fruet, M. Heine, D. G. Jenkins, P. Adsley, L. G. Morris, P. H. Regan, M. Rudigier, D. Montanari, S. Della Negra, N. De Séréville, F. Haas, F. Hammache, O. S. Kirsebom, J. Lesrel, A. Meyer, D. Montanari, K. Auranen, M. L. Avila, A. D. Ayangeakaa, B. B. Back, S. Bottoni, M. Carpenter, C. Dickerson, B. Digiovine, J. P. Greene, D. J. Henderson, C. R. Hoffman, R. V.F. Janssens, B. P. Kay, S. A. Kuvin, T. Lauritsen

Faculty Publications

The 12C+12C fusion reaction is one of the most important for nuclear astrophysics since it determines the carbon ignition in stellar environments. Two experiments which make use of the gamma-particle coincidence technique to measure the 12C+12C S-factors at deep sub barrier energies are discussed. Results are presented showing a decrease of the S-factor below Ec.m. = 3 MeV.

Microfluidic Pore Model Study On Physical And Geomechanical Factors Influencing Fluid Flow Behavior In Porous Media, Shuang Cao

LSU Doctoral Dissertations

Fluid flow in porous media is a subject of fundamental importance and relevant to numerous engineering applications. The comprehensive description of fluid interaction parameters containing wetting properties, fluid-fluid displacement ratio, and capillary pressure, are inevitably needed. Moreover, the fine-grained sediments’ response to various pore fluids and migration in porous media influences reservoir geomechanical properties and pore clogging is essential to a better understanding of fluids flow behavior.

This dissertation provides a detailed study of physical and geomechanical factors influencing fluids flow behavior in porous media. The two-dimensional micromodel tests have been conducted under a wide selection of fluids flow conditions. …

Perchlorate-Coupled Carbon Monoxide (Co) Oxidation: Evidence For A Plausible Microbe-Mediated Reaction In Martian Brines, Marisa R. Myers, Gary M. King

Faculty Publications

© 2017 Myers and King. The presence of hydrated salts on Mars indicates that some regions of its surface might be habitable if suitable metabolizable substrates are available. However, several lines of evidence have shown that Mars' regolith contains only trace levels of the organic matter needed to support heterotrophic microbes. Due to the scarcity of organic carbon, carbon monoxide (CO) at a concentration of about 700 parts per million (about 0.4 Pa) might be the single most abundant readily available substrate that could support near-surface bacterial activity. Although a variety of electron acceptors can be coupled to CO oxidation, …

Simultaneous Multiwavelength Observations Of V404 Cygni During Its 2015 June Outburst Decay Strengthen The Case For An Extremely Energetic Jet-Base, Dipankar Maitra, John F. Scarpaci, Victoria Grinberg, Mark T. Reynolds, Sera Markoff, Thomas J. Maccarone, Robert I. Hynes

Faculty Publications

We present results of multiband optical photometry of the black hole X-ray binary system V404 Cyg obtained using Wheaton College Observatory 0.3 m telescope, along with strictly simultaneous INTEGRAL and Swift observations during 2015 June 25.15-26.33 UT, and 2015 June 27.10-27.34 UT. These observations were made during the 2015 June outburst of the source when it was going through an epoch of violent activity in all wavelengths ranging from radio to γ-rays. The multiwavelength variability timescale favors a compact emission region, most likely originating in a jet outflow, for both observing epochs presented in this work. The simultaneous INTEGRAL/Imager on …

Complete Mitochondrial Genomes Of Three Neotropical Sleeper Gobies: Eleotris Amblyopsis, E. Picta And Hemieleotris Latifasciata (Gobiiformes: Eleotridae), Fernando Alda, Alexandria J. Adams, W. Owen Mcmillan, Prosanta Chakrabarty

Faculty Publications

© 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. We report the first complete mitochondrial genomes of three species of eleotrid fishes from the Pacific and Atlantic watersheds of Panama: Eleotris amblyopsis, E. picta, and Hemieleotris latifasciata. The three species have similar mitochondrial genomes with identical gene order; however, there are differences in the length of control region, 16S rRNA, and in seven of the tRNAs. In addition, ATP8 is one codon shorter in E. picta than in E. amblyopsis or H. latifasciata. We infer a phylogeny for Gobiiformes based on all mitochondrial protein-coding …

Test Beam Studies Of Possibilities To Separate Particles With Gamma Factors Above 103 With Straw Based Transition Radiation Detector, N. Belyaev, M. L. Cherry, S. A. Doronin, K. Filippov, P. Fusco, S. Konovalov, D. Krasnopevtsev, V. Kramarenko, F. Loparco, M. N. Mazziotta, D. Ponomarenko, D. Pyatiizbyantseva, R. Radomskii, C. Rembser, A. Romaniouk, A. Savchenko, E. Shulga, S. Smirnov, Yu Smirnov, V. Sosnovtsev, P. Spinelli, P. Teterin, V. Tikhomirov, K. Vorobev, K. Zhukov

Faculty Publications

Measurements of hadron production in the TeV energy range are one of the tasks of the future studies at the Large Hadron Collider (LHC). The main goal of these experiments is a study of the fundamental QCD processes at this energy range, which is very important not only for probing of the Standard Model but also for ultrahigh-energy cosmic particle physics. One of the key elements of these experiments measurements are hadron identification. The only detector technology which has a potential ability to separate hadrons in this energy range is Transition Radiation Detector (TRD) technology. TRD prototype based on straw …

Measurements Of Angular Distribution And Spectrum Of Transition Radiation With A Gridpix Detector, N. Belyaev, M. L. Cherry, K. Desch, K. Filippov, P. Fusco, J. Kaminski, S. Konovalov, D. Krasnopevtsev, F. Loparco, M. N. Mazziotta, D. Ponomarenko, C. Rembser, A. Romaniouk, A. Savchenko, E. Shulga, S. Smirnov, Yu Smirnov, V. Sosnovtsev, P. Spinelli, M. Strikhanov, P. Teterin, V. Tikhomirov, K. Vorobev, K. Zhukov

Faculty Publications

In recent years, developments of gaseous detectors based on a combination of electron multiplication gap in the gas and pixel readout chips as a part of the anode plane (GasPixel detectors) reached a level where they can offer unique opportunities for particle detection. Transition radiation (TR) detectors based on this technology can be one of the possible applications. In this work, measurements of energy spectra and angular distributions of transition radiation photons produced by particles with different gamma factors made with a GridPix detector prototype are presented. The observed results are compared with theoretical predictions.

Gw170608: Observation Of A 19 Solar-Mass Binary Black Hole Coalescence, 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, M. Afrough, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, A. Allocca, 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

On 2017 June 8 at 02:01:16.49 UTC, a gravitational-wave (GW) signal from the merger of two stellar-mass blackholes was observed by the two Advanced Laser Interferometer Gravitational-Wave Observatory detectors with anetwork signal-to-noise ratio of 13. This system is the lightest black hole binary so far observed, with componentmasses of 12+7-2M⊙7+2-2 (90% credible intervals). These lie in the range of measured black hole masses inlow-mass X-ray binaries, thus allowing us to compare black holes detected through GWs with electromagneticobservations. The source's luminosity distance is 340+140-140corresponding to redshift -0.07+0.03003. We verify thatthe signal waveform is consistent with the predictions of general relativity.

Upper Bounds On Secret-Key Agreement Over Lossy Thermal Bosonic Channels, Eneet Kaur, Mark M. Wilde

Faculty Publications

Upper bounds on the secret-key-agreement capacity of a quantum channel serve as a way to assess the performance of practical quantum-key-distribution protocols conducted over that channel. In particular, if a protocol employs a quantum repeater, achieving secret-key rates exceeding these upper bounds is evidence of having a working quantum repeater. In this paper, we extend a recent advance [Liuzzo-Scorpo, Phys. Rev. Lett. 119, 120503 (2017)PRLTAO0031-900710.1103/PhysRevLett.119.120503] in the theory of the teleportation simulation of single-mode phase-insensitive Gaussian channels such that it now applies to the relative entropy of entanglement measure. As a consequence of this extension, we find tighter upper bounds …

Exploring The Origins Of The Dzyaloshinskii-Moriya Interaction In Mnsi, C. Dhital, L. Debeer-Schmitt, Q. Zhang, W. Xie, D. P. Young, J. F. Ditusa

Faculty Publications

By using magnetization and small-angle neutron scattering measurements, we have investigated the magnetic behavior of the Mn1-xIrxSi system to explore the effect of increased carrier density and spin-orbit interaction on the magnetic properties of MnSi. We determine estimates of the spin wave stiffness and the Dzyaloshinskii-Moriya (DM) interaction strength and compare with Mn1-xCoxSi and Mn1-xFexSi. Despite the large differences in atomic mass and size of the substituted elements, Mn1-xCoxSi and Mn1-xIrxSi show nearly identical variations in their magnetic properties with substitution. We find a systematic dependence of the transition temperature, the ordered moment, the helix period, and the DM interaction …

Dna Base Excision Repair And Double Strand Break Repair In Human Fibroblast, Mingyang Li

LSU Doctoral Dissertations

In eukaryotes, DNA repair mechanisms detect and repair damaged DNA. DNA damage is primarily caused by a variety of exogenous and endogenous sources. Several types of damage to DNA are repaired by different kinds of DNA repair pathways. This dissertation focused on repair of N-methylpurines (NMPs) and double-strand breaks (DSBs) in human fibroblasts.

NMPs, including N⁷-methylguanine (7MeG) and N³-methyladenine (3MeA), can be induced by environmental methylating agents (e.g. the soil fumigant methyl bromide), chemotherapeutics (e.g. nitrogen mustards), and natural cellular methyl donors like S-adenosylmethionine. In human cells, NMPs are repaired by the multi-step …

Orientation Dependence Of Temporal And Spectral Properties Of High-Order Harmonics In Solids, Mengxi Wu, Yongsing You, Shambhu Ghimire, David A. Reis, Dana A. Browne, Kenneth J. Schafer, Mette B. Gaarde

Faculty Publications

We investigate the connection between crystal symmetry and temporal and spectral properties of high-order harmonics in solids. We calculate the orientation-dependent harmonic spectrum driven by an intense, linearly polarized infrared laser field, using a momentum-space description of the generation process in terms of strong-field-driven electron dynamics on the band structure. We show that the orientation dependence of both the spectral yield and the subcycle time profile of the harmonic radiation can be understood in terms of the coupling strengths and relative curvatures of the valence band and the low-lying conduction bands. In particular, we show that in some systems this …

Context-Dependent Chemosensory Signaling, Aggression And Neural Activation Patterns In Gravid Female African Cichlid Fish, Karen E. Field, Karen P. Maruska

Faculty Publications

© 2017. Published by The Company of Biologists Ltd . Social animals must constantly assess their environment to make appropriate behavioral decisions. The use of various sensory modalities is imperative in this process and it is hypothesized that the highly conserved brain nuclei comprising the social decisionmaking network (SDMN) integrates social information with an animal's internal state to elicit behavioral responses. Here, we used the highly social African cichlid fish, Astatotilapia burtoni, to investigate whether reproductively receptive (gravid) females show contextual chemosensory signaling, social behaviors and neural activation patterns within the SDMN. We exposed gravid females to different social contexts: …

Inferences On Mass Composition And Tests Of Hadronic Interactions From 0.3 To 100 Eev Using The Water-Cherenkov Detectors Of The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, I. Al Samarai, I. F.M. Albuquerque, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, G. A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, F. Arqueros, N. Arsene, H. Asorey, P. Assis, J. Aublin, G. Avila, A. M. Badescu, A. Balaceanu, F. Barbato, R. J. Barreira Luz, J. J. Beatty, K. H. Becker, J. A. Bellido, C. Berat, M. E. Bertaina, X. Bertou, P. L. Biermann, J. Biteau, S. G. Blaess

Faculty Publications

We present a new method for probing the hadronic interaction models at ultrahigh energy and extracting details about mass composition. This is done using the time profiles of the signals recorded with the water-Cherenkov detectors of the Pierre Auger Observatory. The profiles arise from a mix of the muon and electromagnetic components of air showers. Using the risetimes of the recorded signals, we define a new parameter, which we use to compare our observations with predictions from simulations. We find, first, inconsistencies between our data and predictions over a greater energy range and with substantially more events than in previous …

Global Awakening Of Cryptic Biosynthetic Gene Clusters In Burkholderia Thailandensis, Ashish Gupta, Renesh Bedre, Sudarshan Singh Thapa, Afsana Sabrin, Guannan Wang, Maheshi Dassanayake, Anne Grove

Faculty Publications

© 2017 American Chemical Society. Many bacteria encode biosynthetic proteins that produce a vast array of natural products. These compounds are often synthesized during host invasion as they function as virulence factors. In addition, such secondary metabolites have yielded numerous molecular scaffolds with pharmaceutical and clinical importance. The gene clusters that encode proteins responsible for synthesis of these compounds are typically silenced or "cryptic" under laboratory growth conditions, hampering discovery of novel lead compounds. We report here that MftR is a global repressor of secondary metabolite synthesis in Burkholderia thailandensis and that urate functions as a physiologically relevant inducer of …

First Narrow-Band Search For Continuous Gravitational Waves From Known Pulsars In Advanced Detector Data, 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, M. Afrough, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, B. Allen, G. Allen, A. Allocca, 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, J. S. Areeda

Faculty Publications

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars …

First Low-Frequency Einstein@Home All-Sky Search For Continuous Gravitational Waves In Advanced Ligo Data, 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, M. Afrough, B. Agarwal, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, B. Allen, G. Allen, A. Allocca, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, N. Arnaud, S. Ascenzi

Faculty Publications

We report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the first Advanced LIGO observing run. This search investigates the low frequency range of Advanced LIGO data, between 20 and 100 Hz, much of which was not explored in initial LIGO. The search was made possible by the computing power provided by the volunteers of the Einstein@Home project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population, corresponding to a sensitivity depth of 48.7 …

Boulder Distribution Analysis Of Impact Craters In The Tharsis Region And Elysium Planitia, Mars, Nicole Button

LSU Master's Theses

Crater counting is an accepted method for dating the surface of a planetary body. An older landscape will have a higher areal density of craters due to exposure of impacts occurring over a longer time period. Since each initial impact only forms one primary crater, secondary craters need to be excluded in the crater counting method to appropriately catalog only distinct impact events. However, small primary craters may be difficult to distinguish from secondary craters. Understanding physical features of impact craters, such as the ejecta blanket, would improve the planetary community’s ability to differentiate between the two types of craters. …

Initiation And Long-Term Instability Of The East Antarctic Ice Sheet, Sean P.S. Gulick, Amelia E. Shevenell, Aleksandr Montelli, Rodrigo Fernandez, Catherine Smith, Sophie Warny, Steven M. Bohaty, Charlotte Sjunneskog, Amy Leventer, Bruce Frederick, Donald D. Blankenship

Faculty Publications

© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Antarctica's continental-scale ice sheets have evolved over the past 50 million years. However, the dearth of ice-proximal geological records limits our understanding of past East Antarctic Ice Sheet (EAIS) behaviour and thus our ability to evaluate its response to ongoing environmental change. The EAIS is marine-terminating and grounded below sea level within the Aurora subglacial basin, indicating that this catchment, which drains ice to the Sabrina Coast, may be sensitive to climate perturbations. Here we show, using marine geological and geophysical data from the continental shelf seaward of …

Characterizations Of Some Classes Of Graphs That Are Nearly Series-Parallel, Victoria Fontaine

LSU Doctoral Dissertations

A series-parallel graph can be built from a single-edge graph by a sequence of series and parallel extensions. The class of such graphs coincides with the class of graphs that do not have the complete graph K₄ as a minor. This dissertation considers a class M₁ of graphs that are close to being series-parallel. In particular, every member of the class has the property that one can obtain a series-parallel graph by adding a new edge and contracting it out, or by splitting a vertex into two vertices whose neighbor sets partition the neighbor set of the original …

Development And Applications Of A Real-Time Magnetic Electron Energy Spectrometer For Use With Medical Linear Accelerators, Paul Ethan Maggi

LSU Doctoral Dissertations

Purpose – This work presents a design for a real-time electron energy spectrometer, and provides data analysis methods and characterization of the real-time system. This system is intended for use with medical linear accelerators (linacs). The goal is 1 Hz acquisition of the energy range 4-25 MeV, reconstructed in 0.1 MeV increments.

Methods – Our spectrometer uses a nominal 0.54 T permanent magnet block as the dispersive element and scintillating fibers coupled to a CCD camera as the position sensitive detector. A broad electron beam produced by a linac is collimated by a 6.35 mm dimeter aperture at the entrance …

Multiphase Flow Modeling For Design And Optimization Of A Novel Down-Flow Bubble Column, Mutharasu Lalitha Chockalingam

LSU Doctoral Dissertations

The application of the Euler-Euler framework based Computational Fluid Dynamics (CFD) models for simulating the two-phase gas-liquid bubbly flow in down-flow bubble columns is discussed in detail. Emphasis is given towards the modelling and design optimization of a novel down-flow bubble column. The design features of this novel down-flow bubble column and its advantages over a conventional Plunging Jet down-flow bubble column are discussed briefly. Then, some of the present challenges in simulating a conventional Plunging Jet down-flow bubble column in the Euler-Euler framework is highlighted, and a sigmoid function based drag modification function is implemented to overcome those challenges. …

Erratum: First Search For Gravitational Waves From Known Pulsars With Advanced Ligo (Astrophysical Journal (2017) 839 (12) Doi: 10.3847/1538-4357/Aa677f), B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, A. Allocca, P. A. Altin, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, N. Arnaud, K. G. Arun, S. Ascenzi, G. Ashton

Faculty Publications

There is an error in Equation?(4) of the original paper, which should instead be (Formula Presented) This makes it consistent with Equation?(3) of Aasi et al. (2014), which was actually used when calculating the value of the Q22 upper limits from the h0 upper limits for the results of this paper.

Search For Post-Merger Gravitational Waves From The Remnant Of The Binary Neutron Star Merger 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, M. Afrough, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, A. Allocca, 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

The first observation of a binary neutron star (NS) coalescence by the Advanced LIGO and Advanced Virgo gravitational-wave (GW) detectors offers an unprecedented opportunity to study matter under the most extreme conditions. After such a merger, a compact remnant is left over whose nature depends primarily on the masses of the inspiraling objects and on the equation of state of nuclear matter. This could be either a black hole (BH) or an NS, with the latter being either long-lived or too massive for stability implying delayed collapse to a BH. Here, we present a search for GWs from the remnant …

Multi-Hazard Performance Assessment Of High-Rise Buildings, Jad El Khoury Antoun

LSU Master's Theses

In the last few decades, there has been an important increase in building high-rise constructions in many cities around the world. Since they offer several benefits in populous areas in terms of space efficiency, economy and sustainability, tower buildings attracted practitioners and researchers to understand better their exclusive behavior and response to natural hazards (e.g., hurricanes, earthquakes). Because of their flexibility and their commonly limited damping, skyscrapers are more susceptible to wind and earthquake actions than low- and mid-rise buildings. Moreover, many locations are prone to multiple hazards; hence, it is important to understand thoroughly the structural behavior of structures …

Surface Enhanced Raman Scattering (Sers) Substrates And Probes, Srismrita Basu

LSU Doctoral Dissertations

Raman spectroscopy is a well-known technique for complex molecular detection. In Raman spectrometry, laser beam is focused on a sample to generate a unique "fingerprint" of the molecule. The Raman signal is very weak. To overcome this problem nano rough metallic substrates are fabricated to enhance the signal strength. In clinical applications, remote contact and minimally invasive probes inside the specimen are needed.

This research work is divided in: (1) development of Surface Enhanced Raman Scattering (SERS) substrate using gold coated etched aluminum foil, (2) development of the SERS probe using the aluminum based substrate with a single optical fiber …

Dinoflagellate Cysts Track Eutrophication In The Northern Gulf Of Mexico, Andrea M. Price, Melissa M. Baustian, R. Eugene Turner, Nancy N. Rabalais, Gail L. Chmura

Faculty Publications

We examined organic-walled dinoflagellate cysts from one 210Pb-dated sediment core and 39 surface sediment samples from the northern Gulf of Mexico to determine the relationship between nutrient enrichment and cyst assemblages in this region characterized by oxygen deficiency. The core spans from 1962 to 1997 and its sampling location is directly influenced by the Mississippi River plume. Surface sediments were collected in 2006, 2007, 2008, and 2014 and represent approximately 1 to 4 years of accumulation. A total of 57 cyst taxa were recorded, and four heterotrophic taxa in particular were found to increase in the top section (1986–1997) of …

Single-Shot Measurement Of The Orbital-Angular-Momentum Spectrum Of Light, Girish Kulkarni, Rishabh Sahu, Omar S. Magaña-Loaiza, Robert W. Boyd, Anand K. Jha

Faculty Publications

The existing methods for measuring the orbital-angular-momentum (OAM) spectrum suffer from issues such as poor efficiency, strict interferometric stability requirements, and too much loss. Furthermore, most techniques inevitably discard part of the field and measure only a post-selected portion of the true spectrum. Here, we propose and demonstrate an interferometric technique for measuring the true OAM spectrum of optical fields in a single-shot manner. Our technique directly encodes the OAM-spectrum information in the azimuthal intensity profile of the output interferogram. In the absence of noise, the spectrum can be fully decoded using a single acquisition of the output interferogram, and, …