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University of Texas Rio Grande Valley

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Articles 1831 - 1860 of 2419

Full-Text Articles in Physical Sciences and Mathematics

Minisuperspace Canonical Quantization Of The Reissner-Nordström Black Hole Via Conditional Symmetries, T. Christodoulakis, N. Dimakis, Petros A. Terzis, Babak Vakili, E. Melas, Th. Grammenos Feb 2014

Minisuperspace Canonical Quantization Of The Reissner-Nordström Black Hole Via Conditional Symmetries, T. Christodoulakis, N. Dimakis, Petros A. Terzis, Babak Vakili, E. Melas, Th. Grammenos

Physics and Astronomy Faculty Publications and Presentations

We use the conditional symmetry approach to study the r evolution of a minisuperspace spherically symmetric model both at the classical and the quantum level. After integration of the coordinates t, θ and ϕ in the gravitational plus electromagnetic action the configuration space dependent dynamical variables turn out to correspond to the r-dependent metric functions and the electrostatic field. In the context of the formalism for constrained systems (Dirac-Bergmann, Arnowitt-Deser-Misner) with respect to the radial coordinate r, we set up a pointlike reparametrization invariant Lagrangian. It is seen that, in the constant potential parametrization of the lapse, the corresponding minisuperspace …


First Searches For Optical Counterparts To Gravitational-Wave Candidate Events, M. Constancio, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. Abbott, Daniel Bessis, Teviet Creighton, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, M. E. Normandin, O. Puncken, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano, Robert Stone, A. S. Stroeer, Cristina V. Torres, D. Vrinceanu Feb 2014

First Searches For Optical Counterparts To Gravitational-Wave Candidate Events, M. Constancio, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. Abbott, Daniel Bessis, Teviet Creighton, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, M. E. Normandin, O. Puncken, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano, Robert Stone, A. S. Stroeer, Cristina V. Torres, D. Vrinceanu

Physics and Astronomy Faculty Publications and Presentations

During the Laser Interferometer Gravitational-wave Observatory and Virgo joint science runs in 2009-2010, gravitational wave (GW) data from three interferometer detectors were analyzed within minutes to select GW candidate events and infer their apparent sky positions. Target coordinates were transmitted to several telescopes for follow-up observations aimed at the detection of an associated optical transient. Images were obtained for eight such GW candidates. We present the methods used to analyze the image data as well as the transient search results. No optical transient was identified with a convincing association with any of these candidates, and none of the GW triggers …


Crucial Positively Charged Residues For Ligand Activation Of The Gpr35 Receptor, Pingwei Zhao, Tom R. Lane, Helen G.L. Gao, Dow P. Hurst, Evangelia Kotsikorou, Long Le, Eugen Brailoiu, Patricia H. Reggio, Mary E. Abood Feb 2014

Crucial Positively Charged Residues For Ligand Activation Of The Gpr35 Receptor, Pingwei Zhao, Tom R. Lane, Helen G.L. Gao, Dow P. Hurst, Evangelia Kotsikorou, Long Le, Eugen Brailoiu, Patricia H. Reggio, Mary E. Abood

Chemistry Faculty Publications and Presentations

GPR35 is a G protein-coupled receptor expressed in the immune, gastrointestinal, and nervous systems in gastric carcinomas and is implicated in heart failure and pain perception. We investigated residues in GPR35 responsible for ligand activation and the receptor structure in the active state. GPR35 contains numerous positively charged amino acids that face into the binding pocket that cluster in two distinct receptor regions, TMH3-4-5-6 and TMH1-2-7. Computer modeling implicated TMH3-4-5-6 for activation by the GPR35 agonists zaprinast and pamoic acid. Mutation results for the TMH1-2-7 region of GPR35 showed no change in ligand efficacies at the K1.32A, R2.65A, R7.33A, and …


Personal Cloud User Acceptance: The Role Of Trust And Perceived Risk In The Technology Acceptance Model, Murad Moqbel, Valerie L. Bartelt, John Cicala Feb 2014

Personal Cloud User Acceptance: The Role Of Trust And Perceived Risk In The Technology Acceptance Model, Murad Moqbel, Valerie L. Bartelt, John Cicala

Information Systems Faculty Publications and Presentations

This research considers technology adoption issues, as well as risk and trust factors, that lead to behavioral intention of personal cloud computing. We are interested in whether similar results are found in personal cloud computing, a tool that may be perceived as having more risks. Our research found that perceived risk decreased behavioral intentions. Perceived usefulness served as a mediator between trust and behavioral intentions, significantly increasing both relationships. Trust was found to decrease perceived risk; however, it directly increased behavioral intention, perceived usefulness, and perceived ease of use. Interestingly, perceived ease of use did not significantly affect behavioral intentions. …


Searching For Pulsars Using Image Pattern Recognition, W. W. Zhu, A. Berndsen, E. C. Madsen, M. Tan, I. H. Stairs, A. Brazier, P. Lazarus, R. Lynch, P. Scholz, K. Stovall, S. M. Ransom, S. Banaszak, C. M. Biwer, S. Cohen, L. P. Dartez, J. Flanigan, G. Lunsford, J. G. Martinez, A. Mata, M. Rohr, A. Walker, B. Allen, N. D.R. Bhat, S. Bogdanov, F. Camilo, S. Chatterjee, J. M. Cordes, F. Crawford, J. S. Deneva, G. Desvignes Feb 2014

Searching For Pulsars Using Image Pattern Recognition, W. W. Zhu, A. Berndsen, E. C. Madsen, M. Tan, I. H. Stairs, A. Brazier, P. Lazarus, R. Lynch, P. Scholz, K. Stovall, S. M. Ransom, S. Banaszak, C. M. Biwer, S. Cohen, L. P. Dartez, J. Flanigan, G. Lunsford, J. G. Martinez, A. Mata, M. Rohr, A. Walker, B. Allen, N. D.R. Bhat, S. Bogdanov, F. Camilo, S. Chatterjee, J. M. Cordes, F. Crawford, J. S. Deneva, G. Desvignes

Physics and Astronomy Faculty Publications and Presentations

In the modern era of big data, many fields of astronomy are generating huge volumes of data, the analysis of which can sometimes be the limiting factor in research. Fortunately, computer scientists have developed powerful data-mining techniques that can be applied to various fields. In this paper, we present a novel artificial intelligence (AI) program that identifies pulsars from recent surveys by using image pattern recognition with deep neural nets - the PICS (Pulsar Image-based Classification System) AI. The AI mimics human experts and distinguishes pulsars from noise and interference by looking for patterns from candidate plots. Different from other …


On Cubic Multisections Of Eisenstein Series, Andrew Alaniz, Timothy Huber Jan 2014

On Cubic Multisections Of Eisenstein Series, Andrew Alaniz, Timothy Huber

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

A systematic procedure for generating cubic multisections of Eisenstein series is given. The relevant series are determined from Fourier expansions for Eisenstein series by restricting the congruence class of the summation index modulo three. We prove that the resulting series are rational functions of η(τ) and η(3τ), where η is the Dedekind eta function. A more general treatment of cubic dissection formulas is given by describing the dissection operators in terms of linear transformations. These operators exhibit properties that mirror those of similarly defined quintic operators.


Analysis Of Localized Diabatic States Beyond The Condon Approximation For Excitation Energy Transfer Processes, Ethan Alguire, Shervin Fatehi, Yihan Shao, Joseph E. Subotnik Jan 2014

Analysis Of Localized Diabatic States Beyond The Condon Approximation For Excitation Energy Transfer Processes, Ethan Alguire, Shervin Fatehi, Yihan Shao, Joseph E. Subotnik

Chemistry Faculty Publications and Presentations

In a previous paper [Fatehi, S.; et al. J. Chem. Phys. 2013, 139, 124112], we demonstrated a practical method by which analytic derivative couplings of Boys-localized CIS states can be obtained. In this paper, we now apply that same method to the analysis of triplet–triplet energy transfer systems studied by Closs and collaborators [Closs, G. L.; et al. J. Am. Chem. Soc.1988, 110, 2652]. For the systems examined, we are able to conclude that (i) the derivative coupling in the BoysOV basis is negligible, and (ii) the diabatic coupling will likely change little over the configuration space explored …


Self-Heating Model Of Spherical Aluminum Nanoparticle Oxidation, Karen S. Martirosyan, Zamart Ramazanova, Maxim Zyskin Jan 2014

Self-Heating Model Of Spherical Aluminum Nanoparticle Oxidation, Karen S. Martirosyan, Zamart Ramazanova, Maxim Zyskin

Physics and Astronomy Faculty Publications and Presentations

Aluminum-oxygen reaction is important in highly energetic and high pressure generating systems. Nanoenergetic thermites include mixtures of nanostructured Al and oxidizer particles. The main distinguishing features of these reactive systems are their significant enthalpy release and tunable rate of energy discharge, which gives rise to a wide range of combustion rates, energy release, and ignition sensitivity. In this paper, we consider rapid oxidation of a spherically symmetric aluminum particle. We use the Cabrera Mott oxidation model to describe the kinetics of oxide growth of an aluminum nanoparticle and to predict reaction temperature and oxidation time. We assume that aluminum particle …


The Cytotoxic Effect Of 2-Acylated-1,4-Naphthohydroquinones On Leukemia/Lymphoma Cells, Diego A. Pedroza, Fernando De Leon, Armando Varela-Ramirez, Carolina Lerma, Renato J. Aguilera, Shizue Mito Jan 2014

The Cytotoxic Effect Of 2-Acylated-1,4-Naphthohydroquinones On Leukemia/Lymphoma Cells, Diego A. Pedroza, Fernando De Leon, Armando Varela-Ramirez, Carolina Lerma, Renato J. Aguilera, Shizue Mito

Chemistry Faculty Publications and Presentations

Here, we tested seven 2-acylated-1,4-hydronaphthoquinones for their cytotoxic effects on a panel of cancer lymphoma/leukemia cells and compared to a non-cancer origin cell line. Several naphthohydroquinones exhibited selective cytotoxic effects on lymphoma/leukemia cells with lowest activity on non-cancer cells. The mode of cell death induced by an acylated naphthohydroquinone, which has a long alkyl chain, was found to be via apoptosis. Furthermore, the naphthohydroquinone provoked mitochondria depolarization and activation of its downstream effector, caspase-3, thus implicating the intrinsic apoptotic pathway as its mechanism to exert cell death.


Influence Of Constant And Periodic Experimental Hypoxic Stress On Atlantic Croaker Otolith Chemistry, John Mohan, Md. Saydur Rahman, Peter Thomas, Benjamin Walther Jan 2014

Influence Of Constant And Periodic Experimental Hypoxic Stress On Atlantic Croaker Otolith Chemistry, John Mohan, Md. Saydur Rahman, Peter Thomas, Benjamin Walther

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

The chemical composition of fish otoliths may provide information on the environmental exposure histories of fishes if ‘vital effects’ on element incorporation are minimal. In order to use redox-sensitive geochemical proxies, such as manganese, in otoliths to quantify sublethal exposure to hypoxia, the relative influence of endogenous and exogenous controls on otolith composition must first be validated. Controlled laboratory experiments were conducted on Atlantic croaker Micropogonias undulatus to examine the response of otolith Sr:Ca, Ba:Ca, Mg:Ca, Mn:Ca, and Na:Ca ratios to either constant or periodic hypoxia treatments for 4 and 10 wk, respectively. Although fish somatic growth and condition were …


Assessing The Optimal Virulence Of Malaria‐Targeting Mosquito Pathogens: A Mathematical Study Of Engineered Metarhizium Anisopliae, Bernhard Konrad, Michael R. Lindstrom, Anja Gumpinger, Jielin Zhu, Daniel Coombs Jan 2014

Assessing The Optimal Virulence Of Malaria‐Targeting Mosquito Pathogens: A Mathematical Study Of Engineered Metarhizium Anisopliae, Bernhard Konrad, Michael R. Lindstrom, Anja Gumpinger, Jielin Zhu, Daniel Coombs

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Background

Metarhizium anisopliae is a naturally occurring fungal pathogen of mosquitoes. Recently, Metarhizium has been engineered to act against malaria by directly killing the disease agent within mosquito vectors and also effectively blocking onward transmission. It has been proposed that efforts should be made to minimize the virulence of the fungal pathogen, in order to slow the development of resistant mosquitoes following an actual deployment.

Results

Two mathematical models were developed and analysed to examine the efficacy of the fungal pathogen. It was found that, in many plausible scenarios, the best effects are achieved with a reduced or minimal pathogen …


A Study Of Personal Cloud Computing: Compatibility, Social Influence, And Moderating Role Of Perceived Familiarity, Murad Moqbel, Valerie L. Bartelt, Mohammed Al-Suqri Jan 2014

A Study Of Personal Cloud Computing: Compatibility, Social Influence, And Moderating Role Of Perceived Familiarity, Murad Moqbel, Valerie L. Bartelt, Mohammed Al-Suqri

Information Systems Faculty Publications and Presentations

Building on a research framework based on the Theory of Reasoned Action (TRA), Innovation Diffusion Technology (IDT), and the Technology Adoption Model (TAM), we propose a model integrating compatibility, social influence, and perceived familiarity given the implicit uncertainty of personal cloud. Our model emphasizes the moderating effect of perceived familiarity on the relationships between both perceived compatibility and social influence on behavioral intention. PLS-based structural equation modeling is employed to test the related propositions empirically. Results from a survey, involving 265 university students, reveal that perceived compatibility explains a larger proportion of the variance in behavioral intention; perceived familiarity plays …


Synthesis Of Novel C-4 Disubstituted Β-Lactams Through Staudinger Cycloaddition Reaction, Robert Rodriguez, Anjali Nambiar, Ram N. Yadav, Bimal K. Banik Jan 2014

Synthesis Of Novel C-4 Disubstituted Β-Lactams Through Staudinger Cycloaddition Reaction, Robert Rodriguez, Anjali Nambiar, Ram N. Yadav, Bimal K. Banik

Chemistry Faculty Publications and Presentations

Synthesis of novel C-4 disubstituted beta-lactam that has N-methyl pyrrole system has been achieved through Staudinger cycloaddition reaction of acid chloride and imine. Interestingly, this reaction has produced a single stereoisomer.


Treatment Of Calibration Uncertainty In Multi-Baseline Cross-Correlation Searches For Gravitational Waves, J. T. Whelan, E. L. Robinson, Joseph D. Romano, E. H. Thrane Jan 2014

Treatment Of Calibration Uncertainty In Multi-Baseline Cross-Correlation Searches For Gravitational Waves, J. T. Whelan, E. L. Robinson, Joseph D. Romano, E. H. Thrane

Physics and Astronomy Faculty Publications and Presentations

Uncertainty in the calibration of gravitational wave (GW) detector data leads to systematic errors, which must be accounted for in setting limits on the strength of GW signals. When cross-correlation measurements are made using data from a pair of instruments, as in searches for a stochastic GW background, the calibration uncertainties of the individual instruments can be combined into an uncertainty associated with the pair. With the advent of multi-baseline GW observation (e.g., networks consisting of multiple detectors such as the LIGO observatories and Virgo), a more sophisticated treatment is called for. We have described how the correlations between calibration …


Implementation Of An F-Statistic All-Sky Search For Continuous Gravitational Waves In Virgo Vsr1 Data, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, Mario C. Diaz, Malik Rakhmanov, Joseph D. Romano, Soma Mukherjee, Volker Quetschke, Teviet Creighton, Robert Stone Jan 2014

Implementation Of An F-Statistic All-Sky Search For Continuous Gravitational Waves In Virgo Vsr1 Data, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, Mario C. Diaz, Malik Rakhmanov, Joseph D. Romano, Soma Mukherjee, Volker Quetschke, Teviet Creighton, Robert Stone

Physics and Astronomy Faculty Publications and Presentations

We present an implementation of the -statistic to carry out the first search in data from the Virgo laser interferometric gravitational wave detector for periodic gravitational waves from a priori unknown, isolated rotating neutron stars. We searched a frequency f0 range from 100 Hz to 1 kHz and the frequency dependent spindown f1 range from Hz s−1 to zero. A large part of this frequency–spindown space was unexplored by any of the all-sky searches published so far. Our method consisted of a coherent search over two-day periods using the -statistic, followed by a search for coincidences among the …


Adapting In-Game Agent Behavior By Observation Of Players Using Learning Behavior Trees, Emmett Tomai, Roberto Flores Jan 2014

Adapting In-Game Agent Behavior By Observation Of Players Using Learning Behavior Trees, Emmett Tomai, Roberto Flores

Computer Science Faculty Publications and Presentations

In this paper we describe Learning Behavior Trees, an extension of the popular game AI scripting technique. Behavior Trees provide an effective way for expert designers to describe complex, in-game agent behaviors. Scripted AI captures human intuition about the structure of behavioral decisions, but suffers from brittleness and lack of the natural variation seen in human players. Learning Behavior Trees are designed by a human designer, but then are trained by observation of players performing the same role, to introduce human-like variation to the decision structure. We show that, using this model, a single hand-designed Behavior Tree can cover a …


A Program For Optical Observations Of Advanced Ligo Early Triggers In The Southern Hemisphere, Matthew Benacquista, Chris Belczynski, Martin Beroiz, Maria Branchesi, Carlos Colazo, Mario C. Diaz, Mancheno Dominguez, Diego Garcia Lambas, Shengnan Liang, Lucas Macri, Tania Peñuela, B. Sanchez, Marcos Schneiter, Cristina V. Torres Jan 2014

A Program For Optical Observations Of Advanced Ligo Early Triggers In The Southern Hemisphere, Matthew Benacquista, Chris Belczynski, Martin Beroiz, Maria Branchesi, Carlos Colazo, Mario C. Diaz, Mancheno Dominguez, Diego Garcia Lambas, Shengnan Liang, Lucas Macri, Tania Peñuela, B. Sanchez, Marcos Schneiter, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

In this poster we present a plan to follow-up optically early triggers from the Advanced LIGO gravitational wave detectors, which will start operating in scientific mode in the northern summer of 2015.


Parallel Phase Modulation Scheme For Interferometric Gravitational-Wave Detectors, M. T. Hartman, V. Quetschke, D. B. Tanner, D. H. Reitze, G. Mueller Jan 2014

Parallel Phase Modulation Scheme For Interferometric Gravitational-Wave Detectors, M. T. Hartman, V. Quetschke, D. B. Tanner, D. H. Reitze, G. Mueller

Physics and Astronomy Faculty Publications and Presentations

Advanced LIGO (aLIGO) requires multiple frequency sidebands to disentangle all of the main interferometer's length signals. This paper presents the results of a risk reduction experiment to produce two sets of frequency sidebands in parallel, avoiding mixed 'sidebands on sidebands'. Two phase modulation frequencies are applied to separate Electro-Optic Modulators (EOMs), with one EOM in each of the two arms of a Mach-Zehnder interferometer. In this system the Mach-Zehnder's arm lengths are stabilized to reduce relative intensity noise in the recombined carrier beam by feeding a corrective control signal back to the Rubidium Titanyl Phosphate (RTP) EOM crystals to drive …


Fabrication Of Yttrium Ferrite Nanoparticles By Solution Combustion Synthesis, A. A. Saukhimov, Mkhitar A. Hobosyan, Gamage C. Dannangoda, N. N. Zhumabekova, S. E. Kumekov Jan 2014

Fabrication Of Yttrium Ferrite Nanoparticles By Solution Combustion Synthesis, A. A. Saukhimov, Mkhitar A. Hobosyan, Gamage C. Dannangoda, N. N. Zhumabekova, S. E. Kumekov

Physics and Astronomy Faculty Publications and Presentations

The ternary oxide system Y-Fe-O presents fascinating magnetic properties that are sensitive to the crystalline size of particles. There is a major challenge to fabricate these materials in nano-crystalline forms due to particle conglomeration during nucleation and synthesis. In this paper we report the fabrication of nano sized crystalline yttrium ferrite by solution combustion synthesis (SCS) where yttrium and iron nitrates were used as metal precursors with glycine as a fuel. The magnetic properties of the product can be selectively controlled by adjusting the ratio of glycine to metal nitrates. Yttrium ferrite nano-powder was obtained by using three concentration of …


Search For Gravitational Radiation From Intermediate Mass Black Hole Binaries In Data From The Second Ligo-Virgo Joint Science Run, J. Aasi, B. P. Abbott, H. Daveloza, S. R. Morriss, Soma Mukherjee, M. E. Normandin, O. Puncken, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Robert Stone, Cristina V. Torres, G. Valdes Jan 2014

Search For Gravitational Radiation From Intermediate Mass Black Hole Binaries In Data From The Second Ligo-Virgo Joint Science Run, J. Aasi, B. P. Abbott, H. Daveloza, S. R. Morriss, Soma Mukherjee, M. E. Normandin, O. Puncken, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Robert Stone, Cristina V. Torres, G. Valdes

Physics and Astronomy Faculty Publications and Presentations

This paper reports on an unmodeled, all-sky search for gravitational waves from merging intermediate mass black hole binaries (IMBHB). The search was performed on data from the second joint science run of the LIGO and Virgo detectors (July 2009–October 2010) and was sensitive to IMBHBs with a range up to ∼200 Mpc, averaged over the possible sky positions and inclinations of the binaries with respect to the line of sight. No significant candidate was found. Upper limits on the coalescence-rate density of nonspinning IMBHBs with total masses between 100 and 450 M⊙ and mass ratios between 0.25 and 1 were …


Unidirectional Lasing Emerging From Frozen Light In Nonreciprocal Cavities, Hamidreza Ramezani, S. Kalish, I. Vitebskiy, T. Kottos Jan 2014

Unidirectional Lasing Emerging From Frozen Light In Nonreciprocal Cavities, Hamidreza Ramezani, S. Kalish, I. Vitebskiy, T. Kottos

Physics and Astronomy Faculty Publications and Presentations

We introduce a class of unidirectional lasing modes associated with the frozen mode regime of nonreciprocal slow-wave structures. Such asymmetric modes can only exist in cavities with broken timereversal and space inversion symmetries. Their lasing frequency coincides with a spectral stationary inflection point of the underlying passive structure and is virtually independent of its size. These unidirectional lasers can be indispensable components of photonic integrated circuitry.


Fluid Dynamic Modeling Of Nano-Thermite Reactions, Karen S. Martirosyan, Maxim Zyskin, Charles M. Jenkins, Yasuyuki Horie Jan 2014

Fluid Dynamic Modeling Of Nano-Thermite Reactions, Karen S. Martirosyan, Maxim Zyskin, Charles M. Jenkins, Yasuyuki Horie

Physics and Astronomy Faculty Publications and Presentations

This paper presents a direct numerical method based on gas dynamic equations to predict pressure evolution during the discharge of nanoenergetic materials. The direct numerical method provides for modeling reflections of the shock waves from the reactor walls that generates pressure-time fluctuations. The results of gas pressure prediction are consistent with the experimental evidence and estimates based on the self-similar solution. Artificial viscosity provides sufficient smoothing of shock wave discontinuity for the numerical procedure. The direct numerical method is more computationally demanding and flexible than self-similar solution, in particular it allows study of a shock wave in its early stage …


Gravity Effect On Electrical Field Generation And Charge Carriers Transfer During Combustion Synthesis Of Sulfides, A. A. Markov, I. A. Filimonov, Karen S. Martirosyan Jan 2014

Gravity Effect On Electrical Field Generation And Charge Carriers Transfer During Combustion Synthesis Of Sulfides, A. A. Markov, I. A. Filimonov, Karen S. Martirosyan

Physics and Astronomy Faculty Publications and Presentations

The effect of gravity on the electric potential generated by the combustion synthesis of zinc sulfide is analyzed using the numerical simulation. Recent experimental studies on generation of electric voltage during combustion synthesis of zinc sulfide (ZnS) have revealed high voltage signals (4 V) with duration about 1 s, which are much higher than those produced by the gas–solid and solid–solid combustion reactions studied previously. These data have raised the question about mechanism of such a phenomenon. In our previous work we developed a novel (distributed) model describing the electric potential generation during combustion synthesis of sulfides (CSS) that didn't …


Bright Microwave Pulses From Psr B0531+21 Observed With A Prototype Transient Survey Receiver, J. A. O'Dea, F. A. Jenet, Tsan Huei Cheng, Chau M. Buu, Martin Beroiz, Sami W. Asmar, J. W. Armstrong Jan 2014

Bright Microwave Pulses From Psr B0531+21 Observed With A Prototype Transient Survey Receiver, J. A. O'Dea, F. A. Jenet, Tsan Huei Cheng, Chau M. Buu, Martin Beroiz, Sami W. Asmar, J. W. Armstrong

Physics and Astronomy Faculty Publications and Presentations

Recent discoveries of transient radio events have renewed interest in time-variable astrophysical phenomena. Many radio transient events are rare, requiring long observing times for reliable statistical study. The National Aeronautics and Space Administration/Jet Propulsion Laboratory's Deep Space Network (DSN) tracks spacecraft nearly continuously with 13 large-aperture, low system temperature radio antennas. During normal spacecraft operations, the DSN processes only a small fraction of the pre-detection bandwidth available from these antennas; any information in the remaining bandwidth, e.g., from an astronomical source in the same antenna beam as the spacecraft, is currently ignored. As a firmware modification to the standard DSN …


Lessons Learned In Establishing Stem Student Cohorts At A Border University And The Effect On Student Retention And Success, Mikhail M. Bouniaev, Immanuel Edinbarough, Bill W. Elliott Jan 2014

Lessons Learned In Establishing Stem Student Cohorts At A Border University And The Effect On Student Retention And Success, Mikhail M. Bouniaev, Immanuel Edinbarough, Bill W. Elliott

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The University of Texas at Brownsville (UTB) serves more than 8,000 students in the Lower Rio Grande Valley area and broader Mexico region. UTB is a Hispanic-serving institution that attracts students from the surrounding areas, including the Mexico border region. The College of Science, Mathematics and Technology (CSMT) established a Science, Technology, Engineering, and Mathematics (STEM) cohort program to help the majority of students to earn a degree in a STEM field in the shortest possible time. The challenges and obstacles encountered during the planning and implementation phase of the STEM cohort program are discussed in this paper, as are …


Application Of A Hough Search For Continuous Gravitational Waves On Data From The Fifth Ligo Science Run, J. Aasi, J. Abadie, B. P. Abbott, Teviet Creighton, H. Daveloza, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Robert Stone, A. S. Stroeer, Lappoon R. Tang, Cristina V. Torres Jan 2014

Application Of A Hough Search For Continuous Gravitational Waves On Data From The Fifth Ligo Science Run, J. Aasi, J. Abadie, B. P. Abbott, Teviet Creighton, H. Daveloza, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Robert Stone, A. S. Stroeer, Lappoon R. Tang, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

We report on an all-sky search for periodic gravitational waves in the frequency range 50–1000 Hz with the first derivative of frequency in the range −8.9 × 10−10 Hz s−1 to zero in two years of data collected during LIGO's fifth science run. Our results employ a Hough transform technique, introducing a χ2 test and analysis of coincidences between the signal levels in years 1 and 2 of observations that offers a significant improvement in the product of strain sensitivity with compute cycles per data sample compared to previously published searches. Since our search yields no surviving candidates, we present …


Search For Gravitational Waves Associated With Γ-Ray Bursts Detected By The Interplanetary Network, J. Aasi, B. P. Abbott, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, M. E. Normandin, Volker Quetschke, O. Puncken, Malik Rakhmanov, K. E. Ramirez, Robert Stone, G. Tellez, Cristina V. Torres, G. Valdes Jan 2014

Search For Gravitational Waves Associated With Γ-Ray Bursts Detected By The Interplanetary Network, J. Aasi, B. P. Abbott, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, M. E. Normandin, Volker Quetschke, O. Puncken, Malik Rakhmanov, K. E. Ramirez, Robert Stone, G. Tellez, Cristina V. Torres, G. Valdes

Physics and Astronomy Faculty Publications and Presentations

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005–2010 during LIGO’s fifth and sixth science runs and Virgo’s first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search …


Search For Gravitational Wave Ringdowns From Perturbed Intermediate Mass Black Holes In Ligo-Virgo Data From 2005–2010, J. Aasi, B. P. Abbott, Matthew Benacquista, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, Volker Quetschke, O. Puncken, Malik Rakhmanov, K. E. Ramirez, Robert Stone, Cristina V. Torres, G. Valdes Jan 2014

Search For Gravitational Wave Ringdowns From Perturbed Intermediate Mass Black Holes In Ligo-Virgo Data From 2005–2010, J. Aasi, B. P. Abbott, Matthew Benacquista, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, Volker Quetschke, O. Puncken, Malik Rakhmanov, K. E. Ramirez, Robert Stone, Cristina V. Torres, G. Valdes

Physics and Astronomy Faculty Publications and Presentations

We report results from a search for gravitational waves produced by perturbed intermediate mass black holes (IMBH) in data collected by LIGO and Virgo between 2005 and 2010. The search was sensitive to astrophysical sources that produced damped sinusoid gravitational wave signals, also known as ringdowns, with frequency 50 ≤ f0=Hz ≤ 2000 and decay timescale 0.0001 ≲ τ=s ≲ 0.1 characteristic of those produced in mergers of IMBH pairs. No significant gravitational wave candidate was detected. We report upper limits on the astrophysical coalescence rates of IMBHs with total binary mass 50 ≤ M=M⊙ ≤ 450 and component mass …


First All-Sky Search For Continuous Gravitational Waves From Unknown Sources In Binary Systems, J. Aasi, B. P. Abbott, Teviet Creighton, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, M. E. Normandin, Volker Quetschke, O. Puncken, Malik Rakhmanov, K. E. Ramirez, Robert Stone, Cristina V. Torres, G. Valdes Jan 2014

First All-Sky Search For Continuous Gravitational Waves From Unknown Sources In Binary Systems, J. Aasi, B. P. Abbott, Teviet Creighton, H. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, M. E. Normandin, Volker Quetschke, O. Puncken, Malik Rakhmanov, K. E. Ramirez, Robert Stone, Cristina V. Torres, G. Valdes

Physics and Astronomy Faculty Publications and Presentations

We present the first results of an all-sky search for continuous gravitational waves from unknown spinning neutron stars in binary systems using LIGO and Virgo data. Using a specially developed analysis program, the TwoSpect algorithm, the search was carried out on data from the sixth LIGO science run and the second and third Virgo science runs. The search covers a range of frequencies from 20 Hz to 520 Hz, a range of orbital periods from 2 to ∼2; 254 h and a frequency- and period-dependent range of frequency modulation depths from 0.277 to 100 mHz. This corresponds to a range …


Biosensors And Nanobiosensors: Design And Applications, Ahmed Touhami Jan 2014

Biosensors And Nanobiosensors: Design And Applications, Ahmed Touhami

Physics and Astronomy Faculty Publications and Presentations

The goal of this chapter is to cover the full scope of biosensors. It offers a survey of the principles, design, operation, and biomedical applications of the most popular types of biosensing devices in use today. By discussing recent research and future trends based on many excellent books and reviews, it is hoped to give the readers a comprehensive view on this fast growing field.