Physical Sciences and Mathematics Commons^™

Search For Subsolar-Mass Ultracompact Binaries In Advanced Ligo's First Observing Run, 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

Physics and Astronomy Faculty Publications and Presentations

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2 M-1.0 M using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2 M, 0.2 M) ultracompact binaries to be less than 1.0×106 Gpc-3 yr-1 and the coalescence rate of a similar distribution of (1.0 M, 1.0 M) ultracompact binaries to be less than 1.9×104 Gpc-3 yr-1 (at 90% confidence). Neither black holes nor neutron stars are expected to …

Identification Of Receptor Ligands In Apo B100 Reveals Potential Functional Domains, Juan Guevara Jr., Jamie Romo Jr., Ernesto Hernandez, Natalia Valentinova Guevara

Physics and Astronomy Faculty Publications and Presentations

LDL, VLDL and other members of the low-density lipoparticles (LLPs) enter cells through a large family of receptors. The actual receptor ligand(s) in apolipoprotein B100, one of the main proteins of LLP, remain(s) unknown. The objective of this study was to identify true receptor ligand(s) in apo B100, a molecule of 4,563 residues. Apo B100 contains 33 analogues of Cardin-Weintraub Arginine/Lysine-based receptor ligand motifs and shares key Lysine motifs and sequence similarity with the LDL receptor-associated protein, RAP, MESD, and heat shock proteins. Eleven FITC-labeled synthetic peptides of 21 – 42 residues, with at least one ligand, were tested for …

Functional Materials, Device Architecture, And Flexibility Of Perovskite Solar Cell, Istiak Hussain, Hoang Phong Tran, Jared R. Jaksik, Justin Moore, Mohammed Jasim Uddin

Chemistry Faculty Publications and Presentations

Perovskite solar cells (PSCs) are an emerging photovoltaic technology that promises to offer facile and efficient solar power generation to meet future energy needs. PSCs have received considerable attention in recent years, have attained power conversion efficiencies (PCEs) over 22%, and are a promising candidate to potentially replace the current photovoltaic technology. The emergence of PSCs has revolutionized photovoltaic research and development because of their high efficiencies, inherent flexibility, the diversity of materials/synthetic methods that can be employed to manufacture them, and the various possible device architectures. Further optimization of material compositions and device architectures will help further improve efficiency …

Mesobot : An Autonomous Underwater Vehicle For Tracking And Sampling Midwater Targets, Dana R. Yoerger, Molly Curran, Justin Fujii, Christopher R. German, Daniel Gomez-Ibanez, Annette F. Govindarajan, Jonathan C. Howland, Joel K. Llopiz, Peter H. Wiebe, Brett W. Hobson, Kakani Katija, Michael Risi, Bruce H. Robison, Cailean J. Wilkinson, Stephen M. Rock, John A. Breier

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Mesobot, a new class of autonomous underwater vehicle, will address specific unmet needs for observing slow-moving targets in the midwater ocean. Mesobot will track targets such as zooplankton, fish, and descending particle aggregates using a control system based on stereo cameras and a combination of thrusters and a variable buoyancy system. The vehicle will also be able to collect biogeochemical and environmental DNA (eDNA) samples using a pumped filter sampler.

Hot Water Treatment As A Kill-Step To Inactivate Escherichia Coli O157:H7, Salmonella Enterica, Listeria Monocytogenes And Enterococcus Faecium On In-Shell Pecans, Karuna Kharel, Veerachandra K. Yemmireddy, Charles J. Graham, Witoon Prinyawiwatkul, Achyut Adhikari

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

In-shell pecans are susceptible to microbial contamination. This study was performed to investigate feasibility of using hot water treatment as a kill-step for food-borne pathogens during pecan shelling. In-shell pecans were subjected to hot water at 70, 80 or 90 °C for 1, 2, 3, 4 or 5 min. The time-temperature treatments to achieve a 5-log reduction of Salmonella enterica, Escherichia coli O157:H7, Listeria monocytogenes, and non-pathogenic Enterococcus faecium were determined. Thermal death values were determined for each tested condition. L. monocytogenes was most susceptible to heat treatment and were reduced by 4.6 ± 0.35 log CFU/g at 70 …

Clio: An Autonomous Vertical Sampling Vehicle For Global Ocean Biogeochemical Mapping, Michael V. Jakuba, John A. Breier, Daniel Gomez-Ibanez, Kaitlyn Tradd, Mak A. Saito

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

We report the design, sea trials, and scientific operation of a fast vertical profiling autonomous underwater vehicle, called Clio, designed to cost-effectively improve the understanding of marine microorganism ecosystem dynamics on a global scale by collecting high-volume filter samples autonomously, in contrast to conventional techniques that require a ship’s wire.

On The Origin Of Crystallinity: A Lower Bound For The Regularity Radius Of Delone Sets, Igor A. Baburin, Mikhail M. Bouniaev, Nikolay Dolbilin, Nikolay Yu. Erokhovets, Alexey Garber, Sergey V. Krivovichev, Egon Schulte

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The mathematical conditions for the origin of long-range order or crystallinity in ideal crystals are one of the very fundamental problems of modern crystallography. It is widely believed that the (global) regularity of crystals is a consequence of `local order', in particular the repetition of local fragments, but the exact mathematical theory of this phenomenon is poorly known. In particular, most mathematical models for quasicrystals, for example Penrose tiling, have repetitive local fragments, but are not (globally) regular. The universal abstract models of any atomic arrangements are Delone sets, which are uniformly distributed discrete point sets in Euclidean d space. …

Isar Autofocus Imaging Algorithm For Maneuvering Targets Based On Phase Retrieval And Gabor Wavelet Transform, Hongyin Shi, Ting Yang, Zhijun Qiao

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The imaging issue of a rotating maneuvering target with a large angle and a high translational speed has been a challenging problem in the area of inverse synthetic aperture radar (ISAR) autofocus imaging, in particular when the target has both radial and angular accelerations. In this paper, on the basis of the phase retrieval algorithm and the Gabor wavelet transform (GWT), we propose a new method for phase error correction. The approach first performs the range compression on ISAR raw data to obtain range profiles, and then carries out the GWT transform as the time-frequency analysis tool for the rotational …

Molten-Salt Synthesis Of Complex Metal Oxide Nanoparticles, Jose P. Zuniga, Maya Abdou, Santosh K. Gupta, Yuanbing Mao

Chemistry Faculty Publications and Presentations

The development of feasible synthesis methods is critical for the successful exploration of novel properties and potential applications of nanomaterials. Here, we introduce the molten-salt synthesis (MSS) method for making metal oxide nanomaterials. Advantages over other methods include its simplicity, greenness, reliability, scalability, and generalizability. Using pyrochlore lanthanum hafnium oxide (La2Hf2O7) as a representative, we describe the MSS protocol for the successful synthesis of complex metal oxide nanoparticles (NPs). Furthermore, this method has the unique ability to produce NPs with different material features by changing various synthesis parameters such as pH, temperature, duration, and post-annealing. By fine-tuning these parameters, we …

Organizational Learning And Green Innovation: Does Environmental Proactivity Matter?, Yali Zhang, Jun Sun, Zhaojun Yang, Shurong Li

Information Systems Faculty Publications and Presentations

Emerging economies face the challenge of striking a balance between development and the environment. To adapt to the changes, organizations must develop dynamic capabilities for green innovation and corporate sustainability. Based on a resource-based view integrated with contingency and stakeholder theories, this study examines how strategic contingency makes differences in the transformation between learning and performance resources through innovation efforts. Oriented toward external and internal stakeholders, respectively, learning resources comprise absorptive capacity and transformative capability, innovation efforts include green product innovation and green process innovation, and performance resources contain green image and competitive advantage. Depicting their mediating relationships moderated by …

Gw170817: Measurements Of Neutron Star Radii And Equation Of State, 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

Physics and Astronomy Faculty Publications and Presentations

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were …

Non-Stationary Platform Inverse Synthetic Aperture Radar Maneuvering Target Imaging Based On Phase Retrieval, Hongyin Shi, Saixue Xia, Qi Qin, Ting Yang, Zhijun Qiao

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

As a powerful signal processing tool for imaging moving targets, placing radar on a non-stationary platform (such as an aerostat) is a future direction of Inverse Synthetic Aperture Radar (ISAR) systems. However, more phase errors are introduced into the received signal due to the instability of the radar platform, making it difficult for popular algorithms to accurately perform motion compensation, which leads to severe effects in the resultant ISAR images. Moreover, maneuvering targets may have complex motion whose motion parameters are unknown to radar systems. To overcome the issue of non-stationary platform ISAR autofocus imaging, a high-resolution imaging method based …

Advanced Cotton Fibers Exhibit Efficient Photocatalytic Self-Cleaning And Antimicrobial Activity, Jared Jaksik, Phong Tran, Veronica Galvez, Isaac Martinez, Darian Ortiz, Andy Ly, Monica Mcentee, Erin M. Durke, Sayeeda Tj Aishee, Margaret Cua, Ahmed Touhami, H. Justin Moore, M. Jasim Uddin

Chemistry Faculty Publications and Presentations

Functional cotton fibers have a wide range of applications in domestic, commercial, and military settings, and so enhancing the properties of these materials can yield substantial benefits. Herein, we report the creation of functional fibers that are self-cleaning, anti-microbial, and protective against UV radiation. A uniform, and high surface area films of TiO2 were deposited on cotton fibers and gold/silver nanoparticles were directly incorporated on the nanostructured TiO2 surface. The synthetic method is simple and the produced TiO2 film is homogenous and the nanoparticles were shown to be effectively distributed on the surface using a simple photocatalytic reduction method. …

Vitamin D: Controversy Cancer And Beyond, Cristian J. Rosales, Debasish Bandyopadhyay

Chemistry Faculty Publications and Presentations

Vitamins are an essential part to wellbeing. This was not something always known however, as the Germ theory was the accepted thesis of the 18th century. It was found that certain accessory factors helped mitigate and even cure these diseases such as beriberi, scurvy, and rickets. Accessory factors, later coined vitamins by Casimir Funk, are an essential constituent of the human diet. Vitamin D is technically not a vitamin but functions as a steroid hormone whose most well-known purpose is calcification of the human skeleton. This helps prevent osteomalacia in adults and rickets, a serious problem in children due to …

An Acoustical Analogue Of A Galactic-Scale Gravitational-Wave Detector, Michael T. Lam, Joseph D. Romano, Joey Key, M. E. Normandin, ‪Jeffrey S. Hazboun

Physics and Astronomy Faculty Publications and Presentations

By precisely monitoring the “ticks” of Nature's most precise clocks (millisecond pulsars), scientists are trying to detect the “ripples in spacetime” (gravitational waves) produced by the inspirals of supermassive black holes in the centers of distant merging galaxies. Here, we describe a relatively simple demonstration that uses two metronomes and a microphone to illustrate several techniques used by pulsar astronomers to search for and detect gravitational waves. An adapted version of this demonstration could be used as an instructional laboratory investigation at the undergraduate level.

Laguna Madre Estuary Program Environmental Strategic Plan - Final Report, Kim D. Jones, Lucy Camacho, T. Sinha, Omar Al-Qudah, Hudson R. Deyoe, Augusto Sanchez Gonzalez, Jungseok Ho, Javier Guerrero

Biology Faculty Publications and Presentations

The goal of this effort is to establish a framework of fundamental information and critical ideas to serve as a basis to assist in supporting legislation to found the 29th National Estuary Program for the Laguna Madre of the Gulf coast of Texas.

The National Estuary Program (NEP) was established by the Clean Water Act Amendments of 1987 (Section 320) to protect nationally significant estuaries threatened by development, pollution and overuse. The U.S. Environmental Protection Agency administers the NEP. The Corpus Christi Bay NEP (now the Coastal Bend Bays and Estuary Program) was among the last estuaries accepted into the …

Particulate Metal Exposures Induce Plasma Metabolome Changes In A Commuter Panel Study, Chandresh N. Ladva, Rachel Golan, Donghai Liang, Roby Greenwald, Douglas I. Walker, Amit U. Raysoni, Vilinh Tran, Tianwei Yu, W. Dana Flanders, Gary W. Miller

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Introduction

Advances in liquid chromatography-mass spectrometry (LC-MS) have enabled high-resolution metabolomics (HRM) to emerge as a sensitive tool for measuring environmental exposures and corresponding biological response. Using measurements collected as part of a large, panel-based study of car commuters, the current analysis examines in-vehicle air pollution concentrations, targeted inflammatory biomarker levels, and metabolomic profiles to trace potential metabolic perturbations associated with on-road traffic exposures.

Methods

A 60-person panel of adults participated in a crossover study, where each participant conducted a highway commute and randomized to either a side-street commute or clinic exposure session. In addition to in-vehicle exposure characterizations, participants …

Development Of Hurricane Storm Surge Model To Predict Coastal Highway Inundation For South Texas, Sara E. Davila, Adan Garza, Jungseok Ho

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Forecasting areas prone to flooding will allow us to send off our information gathered to departments such as TxDOT and the United States Department of Transportation. This would then enable these departments to create appropriate evacuation routes, depicting which roads are clear and which cannot be used in the event of a storm. Simulating hurricanes that have passed through this area such as Dolly in 2008, Beulah in 1967, and Bret in 1999 will display the roads and federal highways that frequently tend to get flooded. Identifying the “danger roads” and which federal highways will ultimately be useful for various …

Conformational Analysis Of A Taddol-Based Phosphoramidite P,N Ligand In A Palladium(Ii) Η3-Π-Allyl Complex, Tülay A. Ateşin, Abdurrahman Atesin, Oscar Rodriguez, Diego Rivera, Lohany Y. Garcia

Chemistry Faculty Publications and Presentations

Highlights

• Two lowest energy conformers differ in allyl conformation, conformer with exo allyl having lower energy.

• Lowest energy conformer has “chair” conformation of 7-membered ring and “edge-on/face-on/face-on/edge-on” array of pH groups.

• Next lowest energy conformer with exo allyl has alternating “edge-on/face-on” arrangement and “twist” 7-membered ring.

• Changes in “chair/twist” conformations with different substrates is possible due to 2.4 kcal/mol energy difference.

• These results explain stereochemical outcome of the reaction, and will guide design of new catalysts.

Abstract

The most stable conformations of a TADDOL-based phosphoramidite P,N ligand coordinated to a palladium(II) η3-π-allyl fragment have been investigated using …

Underwater Adhesive Using Solid–Liquid Polymer Mixes, Alin Cristian Chipara, T. Tsafack, P. S. Owuor, J. Yeon, C. E. Junkermeier, A. C. T. Van Duin, S. Bhowmick, S. A. S. Asif, S. Radhakrishnan, Mircea Chipara

Physics and Astronomy Faculty Publications and Presentations

Instantaneous adhesion between different materials is a requirement for several applications ranging from electronics to biomedicine. Approaches such as surface patterning, chemical cross-linking, surface modification, and chemical synthesis have been adopted to generate temporary adhesion between various materials and surfaces. Because of the lack of curing times, temporary adhesives are instantaneous, a useful property for specific applications that need quick bonding. However, to this day, temporary adhesives have been mainly demonstrated under dry conditions and do not work well in submerged or humid environments. Furthermore, most rely on chemical bonds resulting from strong interactions with the substrate such as acrylate …

Removal Of Cu2+ And Ni2+ From Aqueous Solution Using Sno2 Nanomaterial Effect Of: Ph, Time, Temperature, Interfering Cations, Abigail M. Zepeda, Daisy Gonzalez, Luis Gonzalez Heredia, Karina Marquez, Cesar Perez, Erika Pena, K. Flores, Carolina Valdes, Thomas Eubanks, Jason Parsons, J. Cantu

Chemistry Faculty Publications and Presentations

Tin oxide, SnO2, nanomaterial was synthesized and tested for the removal of Cu2+ and Ni2+ ions from aqueous solutions. Various parameters for the binding were investigated in batch studied, which included pH, time, temperature, and interferences. In addition, isotherm studied were performed to determine the maximum binding capacity for both Cu2+ and Ni2+ ions. The optimal binding pH determined from the effects of pH were to be at pH 5 for both the Cu2+ and Ni2+ ions. The isotherm studies were performed at temperatures of 4°C, 25 °C, and 45 °C for both the Cu2+ and Ni2+ ions and were …

Three-Dimensional Carbon Nanotube Yarn Based Solid State Solar Cells With Multiple Sensitizers Exhibit High Energy Conversion Efficiency, Glenn Grissom, Jared Jaksik, Monica Mcentee, Erin M. Durke, Sayeeda Tj Aishee, Margaret Cua, Okenwa Okoli, Ahmed Touhami, H. Justin Moore, M. Jasim Uddin

Chemistry Faculty Publications and Presentations

Fiber-type dye sensitized solar cells that are non-metallic, flexible, and thread-like in structure have many potential military and functional textile applications. With the use of quantum dots (QD), exciton transfer facilitators (Phenyl-C61-butyric acid methyl ester-PCBM) and Poly(3-hexylthiophene-2,5-diyl-P3HT), and careful preparation of the TiO2 oxide layer deposited on the carbon fiber working electrode, an optimized efficiency of 7.6% was obtained. Carbon nanotube yarn (CNTY) was used to prepare both the working and counter electrodes of the fabricated cells. TiCl4 annealing of the TiO2 layer was carried out and the resulting oxide layer morphology was found to be very uniform. The quantum …

Solution Of Mathematical Model For Gas Solubility Using Fractional-Order Bhatti Polynomials, Muhammad I. Bhatti, Paul Bracken, Nicholas Dimakis, Armando Herrera

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Solutions of a mathematical model for gas solubility in a liquid are attained employing an algorithm based on the generalized Galerkin B-poly basis technique. The algorithm determines a solution of a fractional differential equation in terms of continuous finite number of generalized fractional-order Bhatti polynomial (B-poly) in a closed interval. The procedure uses Galerkin method to calculate the unknown expansion coefficients for constructing a solution to the fractional-order differential equation. Caputo?s fractional derivative is employed to evaluate the derivatives of the fractional B-polys and each term in the differential equation is converted into a matrix problem which is then inverted …

A Formulation Of L-Isothermic Surfaces In Three-Dimensional Minkowski Space, Paul Bracken

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The Cartan structure equations are used to study space-like and time-like isothermic surfaces in three-dimensional Minkowski space in a unified framework. When the lines of curvature of a surface constitute an isothermal system, the surface is called isothermic. This condition serves to define a system of one-forms such that, by means of the structure equations, the Gauss-Codazzi equations for the surface are determined explicitly. A Lax pair can also be obtained from these one-forms for both cases, and, moreover, a nonhomogeneous Schrödinger equation can be associated with the set of space-like surfaces.

Glutathione: A Small Molecule With Big Sense, Cristina E. Raya, Debasish Bandyopadhyay

Chemistry Faculty Publications and Presentations

Glutathione, a peptide found in microbes, plants and animals including human plays a key role in maintaining healthy cells. The peptide exists in both reduced and oxidized forms. Synthesis of GSH occurs in the cytosol of cells, and the extent of glutathione synthesis relies on various factors, such as amino acid availability, protein activity etc. Once synthesized, glutathione exists in both forms: oxidized (GSSG) and reduced (GSH). Oxidized glutathione characterized by its disulfide linkage. On the other hand, presence of a thiol group characterizes the reduced glutathione. This thiol makes the tripeptide an essential component of health; it makes glutathione …

Effect Of Molten Salt Synthesis Processing Duration On The Photo- And Radioluminescence Of Uv- Visible- And X-Ray-Excitable La 2 Hf 2 O 7 :Eu 3+ Nanoparticles, Jose P. Zuniga, Santosh K. Gupta, Maya Abdou, Yuanbing Mao

Chemistry Faculty Publications and Presentations

Ln 3+ -ion-doped nanomaterials possess excellent properties because of their high color purity, longer excited state lifetime, narrow emission, and large Stokes shifts. In this work, we studied the correlation between the luminescence properties of La 2 Hf 2 O 7 :Eu 3+ pyrochlore nanoparticles (NPs) synthesized by a molten salt synthesis (MSS) method at a relatively low temperature and several MSS processing durations (from 1 to 12 h). We synthesized these NPs with different sizes just by changing the MSS processing time without subjecting to high temperature. Raman spectroscopy confirmed the stabilization of the ideal pyrochlore structure of the …

Asymmetric Free-Space Light Transport At Nonlinear Metasurfaces, Nir Shitrit, Jeongmin Kim, David S. Barth, Hamidreza Ramezani, Yuan Wang, Xiang Zhang

Physics and Astronomy Faculty Publications and Presentations

Asymmetric light transport has significantly contributed to fundamental science and revolutionized advanced technology in various aspects such as unidirectional photonic devices, optical diodes, and isolators. While metasurfaces mold wave fronts at will with an ultrathin flat optical element, asymmetric transport of light cannot be fundamentally achieved by any linear system including linear metasurfaces. We report asymmetric transport of free-space light at nonlinear metasurfaces upon transmission and reflection. Moreover, we theoretically derive the nonlinear generalized Snell's laws that were experimentally confirmed by the anomalous nonlinear refraction and reflection. The asymmetric transport at optically thin nonlinear interfaces is revealed by the concept …

Thermodynamic And Kinetic Study Of The Removal Of Cu2+ And Pb2+ Ions From Aqueous Solution Using Fe7s8 Nanomaterial, Jesus Cantu, Diego F. Gonzalez, Yvette Cantu, Thomas Eubanks, Jason Parsons

Chemistry Faculty Publications and Presentations

In the present study, pyrrhotite (Fe7S8) was investigated for the removal of Pb2+ and Cu2+ ions from aqueous solution. The Fe7S8 material was prepared through a solvothermal method and was characterized using XRD. The average particle size for the nanomaterial was determined to be 29.86 ± 0.87 nm using XRD analysis and Scherrer's equation. Batch studies were performed to investigate the effects of pH, time, temperature, interfering ions, and the binding capacity of Pb2+ and Cu2+ ions to the Fe7S8 nanomaterial. During the pH profile studies, the optimum pH for the binding of Pb2+ and Cu2+ was determined to be …

Preconditioning Methods For Thin Scattering Structures Based On Asymptotic Results, Josef A. Sifuentes, Shari Moskow

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We present a method to precondition the discretized Lippmann–Schwinger integral equations to model scattering of time-harmonic acoustic waves through a thin inhomogeneous scattering medium. The preconditioner is based on asymptotic results as the thickness of the third component direction goes to zero and requires solving a two dimensional formulation of the problem at the preconditioning step.

The Implementation Of A Fast-Folding Pipeline For Long-Period Pulsar Searching In The Palfa Survey, E. Parent, V. M. Kaspi, S. M. Ransom, M. Krasteva, C. Patel, P. Scholz, A. Brazier, M. A. Mclaughlin, M. Boyce, W. W. Zhu, Z. Pleunis, B. Allen, S. Bogdanov, K. Caballero, F. Camilo, R. Camuccio, S. Chatterjee, J. M. Cordes, F. Crawford, J. S. Deneva, R. Ferdman, P. C.C. Freire, J. W.T. Hessels, F. A. Jenet, B. Knispel, P. Lazarus, J. Van Leeuwen, A. G. Lyne, R. Lynch, A. Seymour

Physics and Astronomy Faculty Publications and Presentations

The Pulsar Arecibo L-Band Feed Array (PALFA) survey, the most sensitive blind search for radio pulsars yet conducted, is ongoing at the Arecibo Observatory in Puerto Rico. The vast majority of the 180 pulsars discovered by PALFA have spin periods shorter than 2 s. Pulsar surveys may miss long-period radio pulsars owing to the summing of a finite number of harmonic components in conventional Fourier analyses (typically ∼16), or as a result of the strong effect of red noise at low modulation frequencies. We address this reduction in sensitivity by using a time-domain search technique: the fast-folding algorithm (FFA). We …