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Articles 2461 - 2490 of 3168

Full-Text Articles in Physical Sciences and Mathematics

Statistical Modeling Of Microrna Expression With Human Cancers, Ke-Sheng Wang, Yue Pan, Chun Xu Jan 2015

Statistical Modeling Of Microrna Expression With Human Cancers, Ke-Sheng Wang, Yue Pan, Chun Xu

Health & Biomedical Sciences Faculty Publications

MicroRNAs (miRNAs) are small non-coding RNAs (containing about 22 nucleotides) that regulate gene expression. MiRNAs are involved in many different biological processes such as cell proliferation, differentiation, apoptosis, fat metabolism, and human cancer genes; while miRNAs may function as candidates for diagnostic and prognostic biomarkers and predictors of drug response. This paper emphasizes the statistical methods in the analysis of the associations of miRNA gene expression with human cancers and related clinical phenotypes: 1) simple statistical methods include chi-square test, correlation analysis, t-test and one-way ANOVA; 2) regression models include linear and logistic regression; 3) survival analysis approaches such as …

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Universal Computation With Arbitrary Polyomino Tiles In Non-Cooperative Self-Assembly, Sándor P. Fekete, Jacob Hendricks, Matthew J. Patitz, Trent A. Rogers Jan 2015

Universal Computation With Arbitrary Polyomino Tiles In Non-Cooperative Self-Assembly, Sándor P. Fekete, Jacob Hendricks, Matthew J. Patitz, Trent A. Rogers

Computer Science Faculty Publications

In this paper we explore the power of geometry to overcome the limitations of non-cooperative self-assembly. We define a generalization of the abstract Tile Assembly Model (aTAM), such that a tile system consists of a collection of polyomino tiles, the Polyomino Tile Assembly Model (polyTAM), and investigate the computational powers of polyTAM systems at temperature 1, where attachment among tiles occurs without glue cooperation (i.e., without the enforcement that more than one tile already existing in an assembly must contribute to the binding of a new tile). Systems composed of the unit-square tiles of the aTAM at temperature 1 …

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Symmetries Of Monocoronal Tilings, Dirk Frettlöh, Alexey Garber Jan 2015

Symmetries Of Monocoronal Tilings, Dirk Frettlöh, Alexey Garber

School of Mathematical & Statistical Sciences Faculty Publications

The vertex corona of a vertex of some tiling is the vertex together with the adjacent tiles. A tiling where all vertex coronae are congruent is called monocoronal. We provide a classification of monocoronal tilings in the Euclidean plane and derive a list of all possible symmetry groups of monocoronal tilings. In particular, any monocoronal tiling with respect to direct congruence is crystallographic, whereas any monocoronal tiling with respect to congruence (reflections allowed) is either crystallographic or it has a one-dimensional translation group. Furthermore, bounds on the number of the dimensions of the translation group of monocoronal tilings in higher …

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Asymptotic Analysis Of A Magnetized Target Fusion Reactor, Michael R. Lindstrom Jan 2015

Asymptotic Analysis Of A Magnetized Target Fusion Reactor, Michael R. Lindstrom

School of Mathematical & Statistical Sciences Faculty Publications

Nonlinear conservation laws with moving boundaries often arise in applications such as gas dynamics and more recently in the context of nuclear fusion reactors. Gaining insight into the nature of solutions to such models and their dependence upon design parameters is often done numerically. We use formal asymptotics to study a model of a magnetized target fusion reactor for producing energy. We will asymptotically solve the compressible Euler equations with two free moving boundaries, with an algebraic coupling of fluid pressure at one of the free boundaries. The model consists of an intense pressure being imparted on the boundary of …

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Connections Of Zero Curvature And Bäcklund Transformations, Paul Bracken Jan 2015

Connections Of Zero Curvature And Bäcklund Transformations, Paul Bracken

School of Mathematical & Statistical Sciences Faculty Publications

Zero curvature connections in a principal bundle are introduced. It is shown that such connections are very useful in formulating the Bäcklund problem and in constructing transformations. A general technique can be proposed for producing such transformations by defining the relevant connection coefficients appropriately. Finally, several applications of this work to various types of nonlinear partial differential equations will be presented.

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Public Exposure To U.S. Commercial Nuclear Power Plants Induced Disasters, Dean Kyne Jan 2015

Public Exposure To U.S. Commercial Nuclear Power Plants Induced Disasters, Dean Kyne

Sociology Faculty Publications

This study explores the potential risks associated with the 65 U.S.-based commercial nuclear power plants and the distribution of those risks among the populations of both their respective host communities and of the communities located in outlying areas. First, it starts by examining the racial/ethnic composition of the host community populations, as well as the disparities in socioeconomic status that exist, if any, between the host communities and communities located in outlying areas. Second, it utilizes two independent-sample T tests to identify any differences in the sociodemographic compositions of the two areas. Third, it explores regional demographic trends by looking …

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Employees’ Social Networking Site Use Impact On Job Performance: Evidence From Pakistan, Murad Moqbel, Fizza Aftab Jan 2015

Employees’ Social Networking Site Use Impact On Job Performance: Evidence From Pakistan, Murad Moqbel, Fizza Aftab

Information Systems Faculty Publications

This paper reinvestigates the impact of social networking site use by employees on job performance by conducting a methodological replication of Moqbel, Nevo, and Kock (2013) using samples (N=139) from Pakistan. In both studies, social networking site use has significant effects on organizational commitment and job satisfaction, and job satisfaction also has a significant impact on job performance and organizational commitment. In comparison with the U.S., we find that social networking site use in Pakistan has no significant impact on job performance through the mediating effect of job satisfaction, yet has a significant effect on organizational commitment and job satisfaction. …

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An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy Jan 2015

An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The phenomenon of seed dormancy is widespread in plants and serves to prevent all or most of a given population from germinating at the “wrong” time, e.g., during an unusually mild fall in an area subject to typically harsh winters. Seed dormancy is an effective survival strategy in many plant populations, but may greatly complicate efforts to establish large cohorts of seedlings (groups of similar age or developmental stage) needed for re-search and other purposes. In an effort to break seed dormancy in common sunflower, Helianthus annuus L. (Asteraceae), we conducted experiments designed to compare germination times and overall germination …

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Curcumin: A Folklore Remedy From Kitchen On The Way To Clinic As Cancer Drug, Debasish Bandyopadhyay Jan 2015

Curcumin: A Folklore Remedy From Kitchen On The Way To Clinic As Cancer Drug, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Numerous 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 with, antimicrobial, anti-inflammatory, …

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Palladium-Catalyzed C8-Selective C-H Arylation Of Quinoline N-Oxides: Insights Into The Electronic, Steric And Solvation Effects On The Site-Selectivity By Mechanistic And Dft Computational Studies, David E. Stephens, Johant Lakey-Beitia, Abdurrahman Atesin, Tülay A. Ateşin, Gabriel Chavez, Hadi D. Arman, Oleg V. Larionov Jan 2015

Palladium-Catalyzed C8-Selective C-H Arylation Of Quinoline N-Oxides: Insights Into The Electronic, Steric And Solvation Effects On The Site-Selectivity By Mechanistic And Dft Computational Studies, David E. Stephens, Johant Lakey-Beitia, Abdurrahman Atesin, Tülay A. Ateşin, Gabriel Chavez, Hadi D. Arman, Oleg V. Larionov

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

We report herein a palladium-catalyzed C-H arylation of quinoline N-oxides that proceeds with high selectivity in favor of the C8-isomer. This site-selectivity is unusual for palladium, since all of the hitherto described methods of palladium-catalyzed C-H functionalization of quinoline N-oxides are highly C2-selective. The reaction exhibits a broad synthetic scope with respect to quinoline N-oxides and iodoarenes and can be significantly accelerated to sub-hour reaction times under microwave irradiation. The C8-arylation method can be carried out on gram scale and has excellent functional group tolerance. Mechanistic and Density Functional Theory (DFT) computational studies provide evidence for the …

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Prospects For Detection Of Extragalactic Stellar Black Hole Binaries In The Nearby Universe, Matthew Benacquista, Jesus Hinojosa, Alberto Mata, Krzysztof Belczynski Jan 2015

Prospects For Detection Of Extragalactic Stellar Black Hole Binaries In The Nearby Universe, Matthew Benacquista, Jesus Hinojosa, Alberto Mata, Krzysztof Belczynski

Physics & Astronomy Faculty Publications

Stellar mass black hole binaries have individual masses between 10-80 solar masses. These systems may emit gravitational waves at frequencies detectable at Megaparsec distances by space-based gravitational wave observatories. In a previous study, we determined the selection effects of observing these systems with detectors similar to the Laser Interferometer Space Antenna by using a generated population of binary black holes that covered a reasonable parameter space and calculating their signal-to-noise ratio. We further our study by populating the galaxies in our nearby (less than 30 Mpc) universe with binary black hole systems drawn from a distribution found in the Synthetic …

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Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt Jan 2015

Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt

Physics & Astronomy Faculty Publications

Supervised image classifications developed from 23 x 23 cm aerial color-infrared aerial photographs (1:5,000 scale) were used to evaluate temporal changes in vegetative cover occurring within three 150 x 300-m research sites on South Padre Island, Texas. Use of high-resolution digitized imagery (ground pixel resolution of ca. 0.1 m) and survey-grade GPS for positional measurements of ground control points (20-25 1.0m2 targets within each research site) resulted in consistently high levels of geometric accuracy, with root mean square errors (RMSEs) ranging between 0.397 – 2.867. Similarly, use of relatively simple information categories (dry and wet sand, live and dead vegetative …

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Critical Controlled Branching Processes And Their Relatives, George Yanev Jan 2015

Critical Controlled Branching Processes And Their Relatives, George Yanev

School of Mathematical & Statistical Sciences Faculty Publications

This survey aims at collecting and presenting results for one-type, discrete time branching processes with random control functions. In particular, the subclass of critical migration processes with different regimes of immigration and emigration is reviewed in detail. Critical controlled branching processes with continuous state space are also discussed.

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Some Results For The Hodge Decomposition Theorem In Euclidean Three-Space, Paul Bracken Jan 2015

Some Results For The Hodge Decomposition Theorem In Euclidean Three-Space, Paul Bracken

School of Mathematical & Statistical Sciences Faculty Publications

The Hodge Decomposition Theorem plays a significant role in the study of partial differential equations. Several interrelated propositions which are required for the proof of the Hodge theorem in Euclidean three-space are introduced and proved in a novel way.

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Understanding The Gravitational-Wave Hellings And Downs Curve For Pulsar Timing Arrays In Terms Of Sound And Electromagnetic Waves, Fredrick A. Jenet, Joseph D. Romano Jan 2015

Understanding The Gravitational-Wave Hellings And Downs Curve For Pulsar Timing Arrays In Terms Of Sound And Electromagnetic Waves, Fredrick A. Jenet, Joseph D. Romano

Physics & Astronomy Faculty Publications

Searches for stochastic gravitational-wave backgrounds using pulsar timing arrays look for correlations in the timing residuals induced by the background across the pulsars in the array. The correlation signature of an isotropic, unpolarized gravitational-wave background predicted by general relativity follows the so-called Hellings and Downs curve, which is a relatively simple function of the angle between a pair of Earth-pulsar baselines. In this paper, we give a pedagogical discussion of the Hellings and Downs curve for pulsar timing arrays, considering simpler analogous scenarios involving sound and electromagnetic waves. We calculate Hellings-and-Downs-type functions for these two scenarios and develop a framework …

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Imaging, Spectroscopy, Mechanical, Alignment And Biocompatibility Studies Of Electrospun Medical Grade Polyurethane (Carbothane™ 3575a) Nanofibers And Composite Nanofibers Containing Multiwalled Carbon Nanotubes, Faheem A. Sheikh, Javier Macossay-Torres, Travis Cantu, Xujun Zhang, M. Shamshi Hassan, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, Hern Kim, Gary L. Bowlin Jan 2015

Imaging, Spectroscopy, Mechanical, Alignment And Biocompatibility Studies Of Electrospun Medical Grade Polyurethane (Carbothane™ 3575a) Nanofibers And Composite Nanofibers Containing Multiwalled Carbon Nanotubes, Faheem A. Sheikh, Javier Macossay-Torres, Travis Cantu, Xujun Zhang, M. Shamshi Hassan, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, Hern Kim, Gary L. Bowlin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

In the present study, we discuss the electrospinning of medical grade polyurethane (Carbothane™ 3575A) nanofibers containing multi-walled-carbon-nanotubes (MWCNTs). A simple method that does not depend on additional foreign chemicals has been employed to disperse MWCNTs through high intensity sonication. Typically, a polymer solution consisting of polymer/MWCNTs has been electrospun to form nanofibers. Physiochemical aspects of prepared nanofibers were evaluated by SEM, TEM, FT-IR and Raman spectroscopy, confirming nanofibers containing MWCNTs. The biocompatibility and cell attachment of the produced nanofiber mats were investigated while culturing them in the presence of NIH 3T3 fibroblasts. The results from these tests indicated non-toxic behavior …

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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 & Astronomy Faculty Publications

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.

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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

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

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 …

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Sign Me Up! Determining Motivation For High School Chemistry Students Enrolling In A Second Year Chemistry Course, Nilda N. Camarena Dec 2014

Sign Me Up! Determining Motivation For High School Chemistry Students Enrolling In A Second Year Chemistry Course, Nilda N. Camarena

Theses and Dissertations - UTB/UTPA

A sample of 108 Pre-AP Chemistry students in Texas participated in a study to determine motivational factors for enrolling in AP Chemistry and University Chemistry. The factors measured were academic attitude, perceptions of chemistry, confidence level in chemistry, and expectations/experiences in the chemistry class. Students completed two questionnaires, one at the beginning of the year and one at the end. Four high school campuses from two school districts in Texas participated. Two campuses were traditional high schools and two were smaller magnet schools. The results from this study are able to confirm that there are definite correlations between academic attitudes, …

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Two Dimensional Mathematical Model Of Fluid Flow In A Growing Solid Tumor, Adriana Gracia Dec 2014

Two Dimensional Mathematical Model Of Fluid Flow In A Growing Solid Tumor, Adriana Gracia

Theses and Dissertations - UTB/UTPA

We investigate the problem of steady and unsteady fluid flow in a growing solid tumor. We develop a mathematical model for the two dimensional fluid flow in a spherical tumor where the spatial variations of the interstitial velocity, interstitial pressure and the drug concentration within the tumor are, in general, with respect to the radial distance and the latitudinal angle in the spherical coordinates. The expressions for radial and latitudinal variations of the interstitial velocity, interstitial pressure, and the two investigated drug concentrations were determined analytically. We calculated these quantities in the tumor as well as in a corresponding normal …

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Detection Of Gravitational Wave Signals From Ns-Ns Inspirals In Presence Of Non-Stationary Noise, Wenhui Wang Dec 2014

Detection Of Gravitational Wave Signals From Ns-Ns Inspirals In Presence Of Non-Stationary Noise, Wenhui Wang

Theses and Dissertations - UTB/UTPA

Gravitational Wave (GW) detection is an important and inspiring project. Once detected, it will open a new window to understand the universe. The laser interferometer GW detectors, specially LIGO, is the most sensitive detectors at the moment, which can detect GW signal as weak as 10−21. Chirp signal generated by neutron star binaries is a well modeled waveform. One goal of LIGO is to study chirp signal detection. In this field, matched filtering is a widely used method. But since LIGO noise is non-stationary, which will weaken the efficiency of general matched filtering. In this work, a modified matched filtering …

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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 & Statistical Sciences Faculty Publications

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.

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Gps-Miv: The General Purpose System For Multi-Display Interactive Visualization, Irving A. Gonzalez Garza Dec 2014

Gps-Miv: The General Purpose System For Multi-Display Interactive Visualization, Irving A. Gonzalez Garza

Theses and Dissertations - UTB/UTPA

The new age of information has created opportunities for inventions like the internet. These inventions allow us access to tremendous quantities of data. But, with the increase in information there is need to make sense of such vast quantities of information by manipulating that information to reveal hidden patterns to aid in making sense of it. Data visualization systems provide the tools to reveal patterns and filter information, aiding the processes of insight and decision making. The purpose of this thesis is to develop and test a data visualization system, The General Purpose System for Multi-display Interactive Visualization (GPS-MIV). GPS-MIV …

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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 & Statistical Sciences Faculty Publications

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 …

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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, Karla E. Ramirez, Joseph D. Romano, Robert Stone 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, Karla E. Ramirez, Joseph D. Romano, Robert Stone

Physics & Astronomy Faculty Publications

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 …

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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

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

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. …

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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, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov 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, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

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, …

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Pulsar J0453+1559, The 10th Double Neutron Star System In The Universe, Jose Guadalupe Martinez Nov 2014

Pulsar J0453+1559, The 10th Double Neutron Star System In The Universe, Jose Guadalupe Martinez

Theses and Dissertations - UTB/UTPA

Pulsars are neutron stars that spin rapidly, are highly magnetized, and they emit beams of electromagnetic radiation like a lighthouse out in space. These beams of radiation are only observed when the beams face towards Earth and can be measured by a radio telescope. Pulsar studies have an abundance of scientific implementations in solid state physics, general relativity, galactic astronomy, astronomy, planetary physics and have even opened windows in cosmology. This thesis reports the results of a study of pulsar (PSR) J0453+1559, a new binary pulsar discovered in the Arecibo All-Sky 327 MegaHertz Drift Pulsar Survey. The recorded observations of …

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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

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

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 …

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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 & Statistical Sciences Faculty Publications

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 …

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