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University of Texas Rio Grande Valley

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2014

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Articles 1 - 30 of 88

Full-Text Articles in Physical Sciences and Mathematics

Unidirectional Spectral Singularities, Hamidreza Ramezani, Hao Kun Li, Yuan Wang, Xiang Zhang Dec 2014

Unidirectional Spectral Singularities, Hamidreza Ramezani, Hao Kun Li, Yuan Wang, Xiang Zhang

Physics and Astronomy Faculty Publications and Presentations

We propose a class of spectral singularities emerging from the coincidence of two independent singularities with highly directional responses. These spectral singularities result from resonance trapping induced by the interplay between parity-time symmetry and Fano resonances. At these singularities, while the system is reciprocal in terms of a finite transmission, a simultaneous infinite reflection from one side and zero reflection from the opposite side can be realized.


Farmer To Pharmacist: Curcumin As An Anti-Invasive And Antimetastatic Agent For The Treatment Of Cancer, Debasish Bandyopadhyay Dec 2014

Farmer To Pharmacist: Curcumin As An Anti-Invasive And Antimetastatic Agent For The Treatment Of Cancer, Debasish Bandyopadhyay

Chemistry Faculty Publications and Presentations

A huge number of compounds are widely distributed in nature and many of these possess medicinal/biological/pharmacological activity. Curcumin, a polyphenol derived from the rhizomes (underground stems) of Curcuma longa Linn (a member of the ginger family, commonly known as turmeric) is a culinary spice and therapeutic used in India for thousands of years to induce color and flavor in food as well as to treat a wide array of diseases. The origin of turmeric as spice and folklore medicine is so old that it is lost in legend. Curcumin has many beneficial pharmacological effects which includes, but are not limited …


Imaging, Spectroscopic, Mechanical And Biocompatibility Studies Of Electrospun Tecoflex® Eg 80a Nanofibers And Composites Thereof Containing Multiwalled Carbon Nanotubes, Javier Macossay-Torres, Faheem A. Sheikh, Travis Cantu, Thomas Eubanks, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, M. Shamshi Hassan, Myung-Seob Khil, Shivani K. Maffi, Hern Kim, Gary L. Bowlin Dec 2014

Imaging, Spectroscopic, Mechanical And Biocompatibility Studies Of Electrospun Tecoflex® Eg 80a Nanofibers And Composites Thereof Containing Multiwalled Carbon Nanotubes, Javier Macossay-Torres, Faheem A. Sheikh, Travis Cantu, Thomas Eubanks, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, M. Shamshi Hassan, Myung-Seob Khil, Shivani K. Maffi, Hern Kim, Gary L. Bowlin

Chemistry Faculty Publications and Presentations

The present study discusses the design, development and characterization of electrospun Tecoflex® EG 80A class of polyurethane nanofibers and the incorporation of multiwalled carbon nanotubes (MWCNTs) to these materials. Scanning electron microscopy results confirmed the presence of polymer nanofibers, which showed a decrease in fiber diameter at 0.5% wt. and 1% wt. MWCNTs loadings, while transmission electron microscopy showed evidence of the MWCNTs embedded within the polymer matrix. The fourier transform infrared spectroscopy and Raman spectroscopy were used to elucidate the polymer-MWCNTs intermolecular interactions, indicating that the C-N and N-H bonds in polyurethanes are responsible for the interactions with MWCNTs. …


Gradient-Based Compressive Sensing For Noise Image And Video Reconstruction, Huihuang Zhao, Yaonan Wang, Xiaojiang Peng, Zhijun Qiao Dec 2014

Gradient-Based Compressive Sensing For Noise Image And Video Reconstruction, Huihuang Zhao, Yaonan Wang, Xiaojiang Peng, Zhijun Qiao

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this study, a fast gradient-based compressive sensing (FGB-CS) for noise image and video is proposed. Given a noise image or video, the authors first make it sparse by orthogonal transformation, and then reconstruct it by solving a convex optimisation problem with a novel gradient-based method. The main contribution is twofold. Firstly, they deal with the noise signal reconstruction as a convex minimisation problem, and propose a new compressive sensing based on gradient-based method for noise image and video. Secondly, to improve the computational efficiency of gradient-based compressive sensing, they formulate the convex optimisation of noise signal reconstruction under Lipschitz …


Connections Of Zero Curvature And Applications To Nonlinear Partial Differential Equations, Paul Bracken Dec 2014

Connections Of Zero Curvature And Applications To Nonlinear Partial Differential Equations, Paul Bracken

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

A general formulation of zero curvature connections in a principle bundle is presented and some applications are discussed. It is proved that a related connection based on a prolongation in an associated bundle remains zero curvature as well. It is also shown that the connection coefficients can be defined so that the partial differential equation to be studied appears as the curvature term in the structure equations. It is discussed how Lax pairs and Bäcklund tranformations can be formulated for such equations that occur as zero curvature terms.


Improved Upper Limits On The Stochastic Gravitational-Wave Background From 2009–2010 Ligo And Virgo Data, J. Aasi, B. P. Abbott, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, M. E. Normandin, O. Puncken, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Joseph D. Romano, Robert Stone, Cristina V. Torres, G. Valdes Dec 2014

Improved Upper Limits On The Stochastic Gravitational-Wave Background From 2009–2010 Ligo And Virgo Data, J. Aasi, B. P. Abbott, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, M. E. Normandin, O. Puncken, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Joseph D. Romano, Robert Stone, Cristina V. Torres, G. Valdes

Physics and Astronomy Faculty Publications and Presentations

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of ΩGWðfÞ ¼ Ωαðf=fref Þα, we place …


Multimessenger Search For Sources Of Gravitational Waves And High-Energy Neutrinos: Initial Results For Ligo-Virgo And Icecube, M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, D. Altmann, T. Anderson, C. Arguelles, T. C. Arlen, J. Auffenberg, X. Bai, S. W. Barwick, V. Baum, J. J. Beatty, J. Becker Tjus, K. H. Becker, S. Benzvi, P. Berghaus, D. Berley, E. Bernardini, A. Bernhard, D. Z. Besson, G. Binder, D. Bindig, M. Bissok, E. Blaufuss, J. Blumenthal, D. J. Boersma, C. Bohm Nov 2014

Multimessenger Search For Sources Of Gravitational Waves And High-Energy Neutrinos: Initial Results For Ligo-Virgo And Icecube, M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, D. Altmann, T. Anderson, C. Arguelles, T. C. Arlen, J. Auffenberg, X. Bai, S. W. Barwick, V. Baum, J. J. Beatty, J. Becker Tjus, K. H. Becker, S. Benzvi, P. Berghaus, D. Berley, E. Bernardini, A. Bernhard, D. Z. Besson, G. Binder, D. Bindig, M. Bissok, E. Blaufuss, J. Blumenthal, D. J. Boersma, C. Bohm

Physics and Astronomy Faculty Publications and Presentations

We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10-2M c2 at ∼150Hz with ∼60ms duration, …


Limit Distributions Of Random Walks On Stochastic Matrices, Santanu Chakraborty, Arunava Mukherjea Nov 2014

Limit Distributions Of Random Walks On Stochastic Matrices, Santanu Chakraborty, Arunava Mukherjea

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Problems similar to Ann. Prob. 22 (1994) 424–430 and J. Appl. Prob. 23 (1986) 1019–1024 are considered here. The limit distribution of the sequence XnXn−1 ··· X1, where (Xn)n≥1 is a sequence of i.i.d. 2 × 2 stochastic matrices with each Xn distributed as μ, is identified here in a number of discrete situations. A general method is presented and it covers the cases when the random components Cn and Dn (not necessarily independent), (Cn, Dn) being the first column of Xn, have the same (or different) Bernoulli distributions. Thus (Cn, Dn) is valued in {0, r}2, where r is …


Study Of As(Iii) And As(V) Oxoanion Adsorption Onto Single And Mixed Ferrite And Hausmannite Nanomaterials, Sandra Garcia, Saima Sardar, Stephanie Maldonado, Velia Garcia, C Tamez, Jason Parsons Nov 2014

Study Of As(Iii) And As(V) Oxoanion Adsorption Onto Single And Mixed Ferrite And Hausmannite Nanomaterials, Sandra Garcia, Saima Sardar, Stephanie Maldonado, Velia Garcia, C Tamez, Jason Parsons

Chemistry Faculty Publications and Presentations

The removal of arsenic(III) and arsenic(V) from an aqueous solution through adsorption on to Fe3O4, MnFe2O4, 50% Mn substituted Fe3O4, 75% Mn substituted Fe3O4, and Mn3O4 nanomaterials was investigated. Characterization of the nanomaterials using XRD showed only pure phases for Mn3O4, MnFe2O4, and Fe3O4. The 50% and 75% substituted nanomaterials were found to be mixtures of Mn3O4 and Fe3O4. From batch studies the optimum binding pH of arsenic(III) and arsenic(V) to the nanomaterials was determined to be pH 3. The binding capacity for As(III) and As(VI) to the various nanomaterials was determined using Isotherm studies. The binding capacity of Fe3O4 …


A Coherent Method For The Detection And Parameter Estimation Of Continuous Gravitational Wave Signals Using A Pulsar Timing Array, Yan Wang, Soumya D. Mohanty, F. A. Jenet Nov 2014

A Coherent Method For The Detection And Parameter Estimation Of Continuous Gravitational Wave Signals Using A Pulsar Timing Array, Yan Wang, Soumya D. Mohanty, F. A. Jenet

Physics and Astronomy Faculty Publications and Presentations

The use of a high precision pulsar timing array is a promising approach to detecting gravitational waves in the very low frequency regime (10-6-10-9 Hz) that is complementary to ground-based efforts (e.g., LIGO, Virgo) at high frequencies (∼10-103 Hz) and space-based ones (e.g., LISA) at low frequencies (10-4-10-1 Hz). One of the target sources for pulsar timing arrays is individual supermassive black hole binaries which are expected to form in galactic mergers. In this paper, a likelihood-based method for detection and parameter estimation is presented for a monochromatic continuous gravitational wave signal emitted by such a source. The so-called pulsar …


Optimization Of Nanograv's Time Allocation For Maximum Sensitivity To Single Sources, Brian Christy, Ryan Anella, Andrea N. Lommen, Lee Samuel Finn, Richard S. Camuccio, Emma Handzo Oct 2014

Optimization Of Nanograv's Time Allocation For Maximum Sensitivity To Single Sources, Brian Christy, Ryan Anella, Andrea N. Lommen, Lee Samuel Finn, Richard S. Camuccio, Emma Handzo

Physics and Astronomy Faculty Publications and Presentations

Pulsar timing arrays (PTAs) are a collection of precisely timed millisecond pulsars (MSPs) that can search for gravitational waves (GWs) in the nanohertz frequency range by observing characteristic signatures in the timing residuals. The sensitivity of a PTA depends on the direction of the propagating GW source, the timing accuracy of the pulsars, and the allocation of the available observing time. The goal of this paper is to determine the optimal time allocation strategy among the MSPs in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) for a single source of GW under a particular set of assumptions. We …


Gravitational Waves From Individual Supermassive Black Hole Binaries In Circular Orbits: Limits From The North American Nanohertz Observatory For Gravitational Waves, Z. Arzoumanian, A. Brazier, S. Burke-Spolaor, S. J. Chamberlin, S. Chatterjee, J. M. Cordes, P. B. Demorest, X. Deng, T. Dolch, J. A. Ellis, R. D. Ferdman, N. Garver-Daniels, Fredrick A. Jenet, G. Jones, V. M. Kaspi, M. Koop, M. T. Lam, T. J.W. Lazio, A. N. Lommen, D. R. Lorimer, Jing Luo, R. S. Lynch, D. R. Madison, M. A. Mclaughlin, S. T. Mcwilliams, D. J. Nice, N. Palliyaguru, T. T. Pennucci, S. M. Ransom, A. Sesana Oct 2014

Gravitational Waves From Individual Supermassive Black Hole Binaries In Circular Orbits: Limits From The North American Nanohertz Observatory For Gravitational Waves, Z. Arzoumanian, A. Brazier, S. Burke-Spolaor, S. J. Chamberlin, S. Chatterjee, J. M. Cordes, P. B. Demorest, X. Deng, T. Dolch, J. A. Ellis, R. D. Ferdman, N. Garver-Daniels, Fredrick A. Jenet, G. Jones, V. M. Kaspi, M. Koop, M. T. Lam, T. J.W. Lazio, A. N. Lommen, D. R. Lorimer, Jing Luo, R. S. Lynch, D. R. Madison, M. A. Mclaughlin, S. T. Mcwilliams, D. J. Nice, N. Palliyaguru, T. T. Pennucci, S. M. Ransom, A. Sesana

Physics and Astronomy Faculty Publications and Presentations

We perform a search for continuous gravitational waves from individual supermassive black hole binaries using robust frequentist and Bayesian techniques. We augment standard pulsar timing models with the addition of time-variable dispersion measure and frequency variable pulse shape terms. We apply our techniques to the Five Year Data Release from the North American Nanohertz Observatory for Gravitational Waves. We find that there is no evidence for the presence of a detectable continuous gravitational wave; however, we can use these data to place the most constraining upper limits to date on the strength of such gravitational waves. Using the full 17 …


Suppression Of Optical Damage At 532 Nm In Holmium Doped Congruent Lithium Niobate, Eftihia Barnes, Nathan H. O'Connell, Nicolas R. Balli, Madhab Pokhrel, Anush Movsesyan, Edvard Kokanyan, Dhiraj K. Sardar Oct 2014

Suppression Of Optical Damage At 532 Nm In Holmium Doped Congruent Lithium Niobate, Eftihia Barnes, Nathan H. O'Connell, Nicolas R. Balli, Madhab Pokhrel, Anush Movsesyan, Edvard Kokanyan, Dhiraj K. Sardar

Physics and Astronomy Faculty Publications and Presentations

Optical damage experiments were carried out in a series of Holmium doped congruent lithium niobate (Ho:cLN) crystals as a function of dopant concentration and laser intensity. The light induced beam distortion was recorded with a camera and a detector under the pseudo-Zscan configuration. At 532 nm, strong suppression of the optical damage was observed for the 0.94 mol. % doped crystal. Increased resistance to optical damage was also observed at 488 nm. The suppression of the optical damage is predominantly attributed to the reduction of the Nb antisites due to the holmium doping.


Thermodynamics, Kinetics, And Activation Energy Studies Of The Sorption Of Chromium(Iii) And Chromium(Vi) To A Mn 3 O 4 Nanomaterial, Yvette Cantu, Abril Remes, Alejandra Reyna, Denise Martinez, Jahaziel Villarreal, Hilda Ramos, Samantha Trevino, C Tamez, A Martinez, Thomas Eubanks, Jason Parsons Oct 2014

Thermodynamics, Kinetics, And Activation Energy Studies Of The Sorption Of Chromium(Iii) And Chromium(Vi) To A Mn 3 O 4 Nanomaterial, Yvette Cantu, Abril Remes, Alejandra Reyna, Denise Martinez, Jahaziel Villarreal, Hilda Ramos, Samantha Trevino, C Tamez, A Martinez, Thomas Eubanks, Jason Parsons

Chemistry Faculty Publications and Presentations

In this study, a manganese oxide, Mn3O4 was used to remove chromium(III) and chromium(VI) from aqueous solutions. The Mn3O4 nanomaterial was synthesized through a precipitation method, and was characterized using XRD, which confirmed the material had a crystal structure similar to hausmannite. In addition, using Scherrer's equation it was determined that the nanomaterial had an average grain size of 19.5 ± 1.10 nm. A study of the effects of pH on the binding of chromium(III) and chromium(VI) showed that the optimum binding pH was 4 and 3 respectively. Batch isotherm studies were performed to determine the binding capacity of chromium(III), …


Sorption Of Cr(Iii) And Cr(Vi) To High And Low Pressure Synthetic Nano-Magnetite (Fe3o4)Particles, Jason Parsons, Jeffrey Hernandez, Christina M. Gonzalez, J. L. Gardea-Torresdey Oct 2014

Sorption Of Cr(Iii) And Cr(Vi) To High And Low Pressure Synthetic Nano-Magnetite (Fe3o4)Particles, Jason Parsons, Jeffrey Hernandez, Christina M. Gonzalez, J. L. Gardea-Torresdey

Chemistry Faculty Publications and Presentations

The binding of Cr(III) and Cr(VI) to synthetic nano-magnetie particles synthesized under open vessel conditions and a microwave assisted hydrothermal synthesis techniques was investigated. Batch studies showed that the binding of both the Cr(III) and Cr(VI) bound to the nano-materials in a pH dependent manner. The Cr(III) maximized at binding at pH 4 and 100% binding. Similarly, the Cr(VI) ions showed a maximum binding of 100% at pH 4. The data from the time dependency studies showed for the most part the majority of the binding occurred within the first 5 minutes of contact with the nanomaterial and remained constant …


A 24 Hr Global Campaign To Assess Precision Timing Of The Millisecond Pulsar J1713+0747, T. Dolch, M. T. Lam, J. Cordes, S. Chatterjee, C. Bassa, B. Bhattacharyya, D. J. Champion, I. Cognard, K. Crowter, P. B. Demorest, J. W.T. Hessels, G. Janssen, F. A. Jenet, G. Jones, C. Jordan, R. Karuppusamy, M. Keith, V. Kondratiev, M. Kramer, P. Lazarus, T. J.W. Lazio, K. J. Lee, M. A. Mclaughlin, J. Roy, R. M. Shannon, I. Stairs, K. Stovall, J. P.W. Verbiest, D. R. Madison, N. Palliyaguru Oct 2014

A 24 Hr Global Campaign To Assess Precision Timing Of The Millisecond Pulsar J1713+0747, T. Dolch, M. T. Lam, J. Cordes, S. Chatterjee, C. Bassa, B. Bhattacharyya, D. J. Champion, I. Cognard, K. Crowter, P. B. Demorest, J. W.T. Hessels, G. Janssen, F. A. Jenet, G. Jones, C. Jordan, R. Karuppusamy, M. Keith, V. Kondratiev, M. Kramer, P. Lazarus, T. J.W. Lazio, K. J. Lee, M. A. Mclaughlin, J. Roy, R. M. Shannon, I. Stairs, K. Stovall, J. P.W. Verbiest, D. R. Madison, N. Palliyaguru

Physics and Astronomy Faculty Publications and Presentations

The radiomillisecond pulsar J1713+0747 is regarded as one of the highest-precision clocks in the sky and is regularly timed for the purpose of detecting gravitational waves. The International Pulsar Timing Array Collaboration undertook a 24 hr global observation of PSR J1713+0747 in an effort to better quantify sources of timing noise in this pulsar, particularly on intermediate (1.24 hr) timescales. We observed the pulsar continuously over 24 hr with the Arecibo, Effelsberg, GMRT, Green Bank, LOFAR, Lovell, Nancay, Parkes, and WSRT radio telescopes. The combined pulse times-of-arrival presented here provide an estimate of what sources of timing noise, excluding DM …


Sorption Of Cr(Iii) And Cr(Vi) To High And Low Pressure Synthetic Nano-Magnetite (Fe3o4)Particles, Jason Parsons, Jeffrey Hernandez, Christina M. Gonzalez, J. L. Gardea-Torresdey Oct 2014

Sorption Of Cr(Iii) And Cr(Vi) To High And Low Pressure Synthetic Nano-Magnetite (Fe3o4)Particles, Jason Parsons, Jeffrey Hernandez, Christina M. Gonzalez, J. L. Gardea-Torresdey

Chemistry Faculty Publications and Presentations

The binding of Cr(III) and Cr(VI) to synthetic nano-magnetie particles synthesized under open vessel conditions and a microwave assisted hydrothermal synthesis techniques was investigated. Batch studies showed that the binding of both the Cr(III) and Cr(VI) bound to the nano-materials in a pH dependent manner. The Cr(III) maximized at binding at pH 4 and 100% binding. Similarly, the Cr(VI) ions showed a maximum binding of 100% at pH 4. The data from the time dependency studies showed for the most part the majority of the binding occurred within the first 5 minutes of contact with the nanomaterial and remained constant …


First Record Of The Tropical House Gecko Hemidactylus Mabouia (Moreau De Jonnès, 1818) In Texas, Alejandro Fierro-Cabo, August Rentfro Oct 2014

First Record Of The Tropical House Gecko Hemidactylus Mabouia (Moreau De Jonnès, 1818) In Texas, Alejandro Fierro-Cabo, August Rentfro

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

Invasions of the tropical house gecko Hemidactylus mabouia (Moreau de Jonnes, 1818) in the tropical Americas are well documented. While this gecko has been reported as well established and expanding its range in Florida, here we document the first record in the United States outside of this state. We detected a small reproducing population in Cameron County, Brownsville, Texas. We expect a rapid colonization of buildings by this species in southern Texas. We consider that this potential invasion poses novel obstacles to the continued presence of the earlier invasive Mediterranean gecko Hemidactylus turcicus (Linnaeus, 1758) across Texas


Mapping Gravitational-Wave Backgrounds Using Methods From Cmb Analysis: Application To Pulsar Timing Arrays, Jonathan Gair, Joseph D. Romano, Stephen Taylor, Chiara M. F. Mingarelli Oct 2014

Mapping Gravitational-Wave Backgrounds Using Methods From Cmb Analysis: Application To Pulsar Timing Arrays, Jonathan Gair, Joseph D. Romano, Stephen Taylor, Chiara M. F. Mingarelli

Physics and Astronomy Faculty Publications and Presentations

We describe an alternative approach to the analysis of gravitational-wave backgrounds, based on the formalism used to characterize the polarization of the cosmic microwave background. In contrast to standard analyses, this approach makes no assumptions about the nature of the background and so has the potential to reveal much more about the physical processes that generated it. An arbitrary background can be decomposed into modes whose angular dependence on the sky is given by gradients and curls of spherical harmonics. We derive the pulsar timing overlap reduction functions for the individual modes, which are given by simple combinations of spherical …


An Expeditious Green Route Toward 2-Aryl-4- Phenyl-1h-Imidazoles, Debasish Bandyopadhyay, Lauren C. Smith, Daniel R. Garcia, Ram Naresh Yadav, Bimal K. Banik Sep 2014

An Expeditious Green Route Toward 2-Aryl-4- Phenyl-1h-Imidazoles, Debasish Bandyopadhyay, Lauren C. Smith, Daniel R. Garcia, Ram Naresh Yadav, Bimal K. Banik

Chemistry Faculty Publications and Presentations

Background: Azaheterocycles are an important class of compounds because of their highly potent medicinal activities, and the imidazole subcategory is of special interest in regard to drug discovery research.

Findings: An expeditious synthetic protocol of 2-aryl-4-phenyl-1H-imidazoles has been accomplished by reacting phenylglyoxal monohydrate, ammonium acetate, and aldehyde under sonication. Following this green approach a series of 2-aryl-4-phenyl-1H-imidazoles has been synthesized using diversely substituted aldehydes.

Conclusions: A rapid and simple synthetic procedure to synthesize diversely substituted 2-aryl-4-phenyl-1H-imidazoles has been reported. Other salient features of this protocol include milder conditions, atom-economy, easy extraction, and minimum wastes. The present procedure may find application …


On The Approximability Of The Exemplar Adjacency Number Problem For Genomes With Gene Repetitions, Zhinxiag Chen, Bin Fu, Randy Goebel, Guohui Lin, Weitian Tong, Jinhui Xu, Boting Yang, Zhiyu Zhao, Binhai Zhu Sep 2014

On The Approximability Of The Exemplar Adjacency Number Problem For Genomes With Gene Repetitions, Zhinxiag Chen, Bin Fu, Randy Goebel, Guohui Lin, Weitian Tong, Jinhui Xu, Boting Yang, Zhiyu Zhao, Binhai Zhu

Computer Science Faculty Publications and Presentations

In this paper, we apply a measure, exemplar adjacency number, which complements and extends the well-studied breakpoint distance between two permutations, to measure the similarity between two genomes (or in general, between any two sequences drawn from the same alphabet). For two genomes and drawn from the same set of n gene families and containing gene repetitions, we consider the corresponding Exemplar Adjacency Number problem (EAN), in which we delete duplicated genes from and such that the resultant exemplar genomes (permutations) G and H have the maximum adjacency number. We obtain the following results. First, we prove that the one-sided …


Energy And Potential Enstrophy Flux Constraints In Quasi-Geostrophic Models, Eleftherios Gkioulekas Sep 2014

Energy And Potential Enstrophy Flux Constraints In Quasi-Geostrophic Models, Eleftherios Gkioulekas

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We investigate an inequality constraining the energy and potential enstrophy flux spectra in two-layer and multi-layer quasi-geostrophic models. Its physical significance is that it can diagnose whether any given multi-layer model that allows co-existing downscale cascades of energy and potential enstrophy can allow the downscale energy flux to become large enough to yield a mixed energy spectrum where the dominant k−3 scaling is overtaken by a subdominant k−5/3 contribution beyond a transition wavenumber kt situated in the inertial range. The validity of the flux inequality implies that this scaling transition cannot occur within the inertial range, whereas a violation of …


Advances In Molecular Quantum Chemistry Contained In The Q-Chem 4 Program Package, Yihan Shao, Zhengting Gan, Evgeny Epifanovsky, Andrew T. B. Gilbert, Michael Wormit, Shervin Fatehi Sep 2014

Advances In Molecular Quantum Chemistry Contained In The Q-Chem 4 Program Package, Yihan Shao, Zhengting Gan, Evgeny Epifanovsky, Andrew T. B. Gilbert, Michael Wormit, Shervin Fatehi

Chemistry Faculty Publications and Presentations

A summary of the technical advances that are incorporated in the fourth major release of the Q-CHEM quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of …


Theoretical And Experimental Infrared Spectra Of Hydrated And Dehydrated Sulfonated Poly(Ether Ether Ketone), Jonathan Doan, Erin Kingston, Ian Kendrick, Kierstyn Anderson, N. Dimakis, Philippe Knauth, Maria Luisa Di Vona, Eugene S. Smotkina Sep 2014

Theoretical And Experimental Infrared Spectra Of Hydrated And Dehydrated Sulfonated Poly(Ether Ether Ketone), Jonathan Doan, Erin Kingston, Ian Kendrick, Kierstyn Anderson, N. Dimakis, Philippe Knauth, Maria Luisa Di Vona, Eugene S. Smotkina

Physics and Astronomy Faculty Publications and Presentations

Time-dependent FT-IR spectra of sulfonated poly(ether ether ketone) during dehydration show diminishing 1081 cm−1 and 1023 cm−1 band intensities concurrent with the emergence and shifting of bands at 1362 cm−1 and 898 cm−1. Animations of density functional theory calculated normal modes enable assignment of the 1081 cm−1 and 1023 cm−1 bands as group modes that include a sulfonate exchange site with C3v local symmetry, while the 1362 cm−1 and 898 cm−1 bands are assigned as group modes that include an associated sulfonic acid with no local symmetry (C1). In contrast to analogously assigned Nafion group mode bands, the SPEEK C3v …


Publisher’S Note: “Derivative Couplings Between Tddft Excited States Obtained By Direct Differentiation In The Tamm-Dancoff Approximation” [J. Chem. Phys. 141, 024114 (2014)], Qi Ou, Shervin Fatehi, Ethan Alguire, Yihan Shao, Joseph Subotnik Aug 2014

Publisher’S Note: “Derivative Couplings Between Tddft Excited States Obtained By Direct Differentiation In The Tamm-Dancoff Approximation” [J. Chem. Phys. 141, 024114 (2014)], Qi Ou, Shervin Fatehi, Ethan Alguire, Yihan Shao, Joseph Subotnik

Chemistry Faculty Publications and Presentations

No abstract provided.


The Green Bank Northern Celestial Cap Pulsar Survey. I. Survey Description Data Analysis And Initial Results, K. Stovall, R. S. Lynch, S. M. Ransom, A. M. Archibald, S. Banaszak, C. M. Biwer, J. Boyles, L. P. Dartez, D. Day, A. J. Ford, J. Flanigan, A. Garcia, J. W.T. Hessels, J. Hinojosa, F. A. Jenet, D. L. Kaplan, C. Karako-Argaman, V. M. Kaspi, V. I. Kondratiev, S. Leake, D. R. Lorimer, G. Lunsford, J. G. Martinez, A. Mata, M. A. Mclaughlin, M. S.E. Roberts, M. D. Rohr, X. Siemens, I. H. Stairs, J. Van Leeuwen Aug 2014

The Green Bank Northern Celestial Cap Pulsar Survey. I. Survey Description Data Analysis And Initial Results, K. Stovall, R. S. Lynch, S. M. Ransom, A. M. Archibald, S. Banaszak, C. M. Biwer, J. Boyles, L. P. Dartez, D. Day, A. J. Ford, J. Flanigan, A. Garcia, J. W.T. Hessels, J. Hinojosa, F. A. Jenet, D. L. Kaplan, C. Karako-Argaman, V. M. Kaspi, V. I. Kondratiev, S. Leake, D. R. Lorimer, G. Lunsford, J. G. Martinez, A. Mata, M. A. Mclaughlin, M. S.E. Roberts, M. D. Rohr, X. Siemens, I. H. Stairs, J. Van Leeuwen

Physics and Astronomy Faculty Publications and Presentations

We describe an ongoing search for pulsars and dispersed pulses of radio emission, such as those from rotating radio transients (RRATs) and fast radio bursts, at 350 MHz using the Green Bank Telescope. With the Green Bank Ultimate Pulsar Processing Instrument, we record 100 MHz of bandwidth divided into 4096 channels every 81.92 μs. This survey will cover the entire sky visible to the Green Bank Telescope (δ > -40°, or 82% of the sky) and outside of the Galactic Plane will be sensitive enough to detect slow pulsars and low dispersion measure (<30 pc cm-3) millisecond pulsars (MSPs) with a 0.08 duty cycle down to 1.1 mJy. For pulsars with a spectral index of -1.6, we will be 2.5 times more sensitive than previous and ongoing surveys over much of our survey region. Here we describe the survey, the data analysis pipeline, initial discovery parameters for 62 pulsars, and timing solutions for 5 new pulsars. PSR J0214+5222 is an MSP in a long-period (512 days) orbit and has an optical counterpart identified in archival data. PSR J0636+5129 is an MSP in a very short-period (96 minutes) orbit with a very low mass companion (8 M J). PSR J0645+5158 is an isolated MSP with a timing residual RMS of 500 ns and has been added to pulsar timing array experiments. PSR J1434+7257 is an isolated, intermediate-period pulsar that has been partially recycled. PSR J1816+4510 is an eclipsing MSP in a short-period orbit (8.7 hr) and may have recently completed its spin-up phase. © 2014. The American Astronomical Society. All rights reserved..


Exposure To Traffic Pollution, Acute Inflammation And Autonomic Response In A Panel Of Car Commuters, Jeremy A. Sarnat, Rachel Golan, Roby Greenwald, Amit U. Raysoni, Priya Kewada, Andrea Winquist, Stefanie E. Sarnat, W. Dana Flanders, Maria C. Mirabelli, Jennifer E. Zora Aug 2014

Exposure To Traffic Pollution, Acute Inflammation And Autonomic Response In A Panel Of Car Commuters, Jeremy A. Sarnat, Rachel Golan, Roby Greenwald, Amit U. Raysoni, Priya Kewada, Andrea Winquist, Stefanie E. Sarnat, W. Dana Flanders, Maria C. Mirabelli, Jennifer E. Zora

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

Background

Exposure to traffic pollution has been linked to numerous adverse health endpoints. Despite this, limited data examining traffic exposures during realistic commutes and acute response exists. Objectives: We conducted the Atlanta Commuters Exposures (ACE-1) Study, an extensive panel-based exposure and health study, to measure chemically-resolved in-vehicle exposures and corresponding changes in acute oxidative stress, lipid peroxidation, pulmonary and systemic inflammation and autonomic response.

Methods

We recruited 42 adults (21 with and 21 without asthma) to conduct two 2-h scripted highway commutes during morning rush hour in the metropolitan Atlanta area. A suite of in-vehicle particulate components were measured in …


Anxiety, Depression And Smoking Status Among Adults Of Mexican Heritage On The Texas-Mexico Border, Anna V. Wilkinson, Kristina Vatcheva, Adriana Pérez, Belinda M. Reininger, Joseph B. Mccormick, Susan P. Fisher-Hoch Aug 2014

Anxiety, Depression And Smoking Status Among Adults Of Mexican Heritage On The Texas-Mexico Border, Anna V. Wilkinson, Kristina Vatcheva, Adriana Pérez, Belinda M. Reininger, Joseph B. Mccormick, Susan P. Fisher-Hoch

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The goal of the current analysis is to examine relationships between smoking status and anxiety and depression among adults of Mexican heritage to inform the development of culturally relevant smoking cessations efforts. Mexican heritage residents (N=1,791) of the city of Brownsville, TX, aged 18 years or older, enrolled in the Cameron County Hispanic Cohort, were selected through two stage cluster sampling of randomly selected census tracts from the first and third quartile of SES using Census 2000. Among current smokers, anxiety and depression scores were highest among women who had not completed high school (p<0.05). Former smoking women, but not men, with at least a high school education and former smoking women born in the United States reported higher levels of anxiety and depression than never smoking women. Negative affective states may represent a greater barrier to smoking cessation among women than men.


Fast Radio Burst Discovered In The Arecibo Pulsar Alfa Survey, L. G. Spitler, J. M. Cordes, J. W.T. Hessels, D. R. Lorimer, M. A. Mclaughlin, S. Chatterjee, F. Crawford, J. S. Deneva, V. M. Kaspi, R. S. Wharton, B. Allen, S. Bogdanov, A. Brazier, F. Camilo, P. C.C. Freire, F. A. Jenet, C. Karako-Argaman, B. Knispel, P. Lazarus, K. J. Lee, J. Van Leeuwen, R. Lynch, S. M. Ransom, P. Scholz, X. Siemens, I. H. Stairs, K. Stovall, J. K. Swiggum, A. Venkataraman, W. W. Zhu Aug 2014

Fast Radio Burst Discovered In The Arecibo Pulsar Alfa Survey, L. G. Spitler, J. M. Cordes, J. W.T. Hessels, D. R. Lorimer, M. A. Mclaughlin, S. Chatterjee, F. Crawford, J. S. Deneva, V. M. Kaspi, R. S. Wharton, B. Allen, S. Bogdanov, A. Brazier, F. Camilo, P. C.C. Freire, F. A. Jenet, C. Karako-Argaman, B. Knispel, P. Lazarus, K. J. Lee, J. Van Leeuwen, R. Lynch, S. M. Ransom, P. Scholz, X. Siemens, I. H. Stairs, K. Stovall, J. K. Swiggum, A. Venkataraman, W. W. Zhu

Physics and Astronomy Faculty Publications and Presentations

Recent work has exploited pulsar survey data to identify temporally isolated, millisecond-duration radio bursts with large dispersion measures (DMs). These bursts have been interpreted as arising from a population of extragalactic sources, in which case they would provide unprecedented opportunities for probing the intergalactic medium; they may also be linked to new source classes. Until now, however, all so-called fast radio bursts (FRBs) have been detected with the Parkes radio telescope and its 13-beam receiver, casting some concern about the astrophysical nature of these signals. Here we present FRB 121102, the first FRB discovery from a geographic location other than …


Illustrations And Supporting Texts For Sound Standing Waves Of Air Columns In Pipes In Introductory Physics Textbooks, Liang Zeng, Chris Smith, G. Herold Poelzer, Jennifer Rodriguez, Edgar Corpuz, George Yanev Jul 2014

Illustrations And Supporting Texts For Sound Standing Waves Of Air Columns In Pipes In Introductory Physics Textbooks, Liang Zeng, Chris Smith, G. Herold Poelzer, Jennifer Rodriguez, Edgar Corpuz, George Yanev

Physics and Astronomy Faculty Publications and Presentations

In our pilot studies, we found that many introductory physics textbook illustrations with supporting text for sound standing waves of air columns in open-open, open-closed, and closed-closed pipes inhibit student understanding of sound standing wave phenomena due to student misunderstanding of how air molecules move within these pipes. Based on the construct of meaningful learning from cognitive psychology and semiotics, a quasiexperimental study was conducted to investigate the comparative effectiveness of two alternative approaches to student understanding: a traditional textbook illustration approach versus a newly designed air molecule motion illustration approach. Thirty volunteer students from introductory physics classes were randomly …