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The Pan American (2011-09-29), Alma E. Hernandez, Roxann Garcia

UTPA Archives - The Pan American Newspaper

Vol. 68, No. 5

The Pan American (2011-09-29), Sandra Gonzalez

UTPA Archives - The Pan American Newspaper

Vol. 68, No. 5

The Collegian (2011-09-26), Rene Cardona Jr.

UTB/TSC Archives - The Collegian [Newspaper]

Vol. 64. No. 6

The Pan American (2011-09-22), Alma E. Hernandez, Roxann Garcia

UTPA Archives - The Pan American Newspaper

Vol. 68, No. 4

The Collegian (2011-09-19), Rene Cardona Jr.

UTB/TSC Archives - The Collegian [Newspaper]

Vol. 64. No. 5

Sparse Spectral-Tau Method For The Three-Dimensional Helically Reduced Wave Equation On Two-Center Domains, Stephen R. Lau, Richard H. Price

Physics & Astronomy Faculty Publications

We describe a multidomain spectral-tau method for solving the three-dimensional helically reduced wave equation on the type of two-center domain that arises when modeling compact binary objects in astrophysical applications. A global two-center domain may arise as the union of Cartesian blocks, cylindrical shells, and inner and outer spherical shells. For each such subdomain, our key objective is to realize certain (differential and multiplication) physical-space operators as matrices acting on the corresponding set of modal coefficients. We then achieve sparse realizations through the integration “preconditioning” of Coutsias, Hagstrom, Hesthaven, and Torres. Since ours is the first three-dimensional multidomain implementation of …

Ferromagnetic Resonance On Ni Nanowire Arrays, Mircea Chipara, Ralph Skomski, Roger D. Kirby, David J. Sellmyer

Physics & Astronomy Faculty Publications

Ferromagnetic resonance investigations on Ni nanowires are reported. The angular dependence of the resonance line position is analyzed within a thermodynamic approach that includes shape anisotropy (ellipsoids of revolution), magnetocrystalline anisotropies (cubic and uniaxial), and dipole–dipole interactions. The results are supported by hysteresis loops, obtained on the same sample.

Bismuth Nitrate Pentahydrate-Induced Novel Nitration Of Eugenol, Luis Canales, Debasish Bandyopadhyay, Bimal K. Banik

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

Background: Eugenol, the main constituent of clove oil possesses a number of medicinal activities. To enhance the medicinal property, structural modification is required. On the other hand, bismuth nitrate pentahydrate has been established as an excellent eco-friendly nitrating agent for several classes of organic compounds.

Results: Bismuth nitrate pentahydrate-induced nitration of eugenol has been investigated very thoroughly. Twenty five different conditions have been studied. The microwave-induced solvent-free reaction has been identified as the best condition.

Conclusions: Spectral analyses confirm that 5-nitroeugenol is the sole product in all the cases. No oxidized or isomerized product could be detected.

Compact Binaries In Star Clusters - Ii. Escapers And Detection Rates, J. M.B. Downing, M. J. Benacquista, M. Giersz, R. Spurzem

Physics & Astronomy Faculty Publications

We use a self-consistent Monte Carlo treatment of stellar dynamics to investigate black hole binaries that are dynamically ejected from globular clusters in order to determine if they will be gravitational wave sources. We find that many of the ejected binaries initially have short periods and will merge within a Hubble time due to gravitational wave radiation. Thus they are potential sources for ground-based gravitational wave detectors. We estimate the yearly detection rate for current and advanced ground-based detectors and find an enhancement over the rate predicted for binaries produced by pure stellar evolution in galactic fields. We conclude that, …

The Collegian (2011-08-29), Rene Cardona Jr.

UTB/TSC Archives - The Collegian [Newspaper]

Vol. 64, No. 2

The Pan American (2011-08-29), Alma E. Hernandez, Roxann Garcia

UTPA Archives - The Pan American Newspaper

Vol. 68, No. 1

Beating The Spin-Down Limit On Gravitational Wave Emission From The Vela Pulsar, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya D. Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We present direct upper limits on continuous gravitational wave emission from the Vela pulsar using data from the Virgo detector's second science run. These upper limits have been obtained using three independent methods that assume the gravitational wave emission follows the radio timing. Two of the methods produce frequentist upper limits for an assumed known orientation of the star's spin axis and value of the wave polarization angle of, respectively, 1.9 × 10-24 and 2.2 × 10-24, with 95% confidence. The third method, under the same hypothesis, produces a Bayesian upper limit of 2.1 × 10-24, with 95% degree of …

Creation Of Post Ap Chemistry Class, Julian Medrano

Theses and Dissertations - UTB/UTPA

The creation of a Post AP Chemistry Class to be taught at the high school level for grade 12 students is discussed. The class is to be taught under the supervision of the University of Texas Pan American professors and taught by an MS Chemistry teacher, in order to better transition students into upper level chemistry courses beyond Chemistry 1401 and 1402.

The First-Integral Method For Duffing-Van Der Pol-Type Oscillator System, Xiaochuan Hu

Theses and Dissertations - UTB/UTPA

In this thesis, we restrict our attention to nonlinear Duffing–van der Pol–type oscillator system by means of the First-integral method. This system has physical relevance as a model in certain flow-induced structural vibration problems, which includes the van der Pol oscillator and the damped Duffing oscillator etc as particular cases. Firstly we apply the Division Theorem for two variables in the complex domain, which is based on the ring theory of commutative algebra, to explore a quasi-polynomial first integral to an equivalent autonomous system. Then through a certain parametric condition, we derive a more general first integral of the Duffing–van …

Life Stories Of Four Conjunto Musicians: Adding To The Culturally Relevant Curriculum Of The Rio Grande Valley Schools, Andres Martinez

Theses and Dissertations - UTB/UTPA

This study examines music and culture and their importance in the learning process. As early as 1838, Horace Mann and later John Dewey (1916), Tim Brophy (1992) and others were expounding the benefits of music as a necessary element of the school curriculum. Julio Cammarota (2008), Geneva Gay (2000), Alan Singer (1994), Banks and Banks (1989) and others have argued for the importance of culture in the curriculum to enhance learning. Both elements have a unique place in the school curriculum. A brief history of the genre is presented beginning with the early years (mid 1800s), the development years (early …

Modeling Instabilities Of Electrically Driven Jets Under Constant Or Variable Applied Field And Non-Zero Basic State Velocity, Sayantan Das

Theses and Dissertations - UTB/UTPA

We investigate the problem of instability of electrically forced axisymmetric jets with respect to temporally and spatially growing disturbances, within parameter regimes that affects the process of electrospinnning. Deriving a dispersion relation based on the relevant approximated versions of the equations of the electro-hydrodynamics for an electrically forced jet flow. For temporal instability, we find in the non-zero basic state velocity, the growth rate of the unstable mode is unaffected by the value of the basic state velocity. But, the basic state velocity affects the period of the unstable mode in the sense that it decreases the period, and the …

Using Discrete Event Computer Simulation To Analyze The Effects Of Proposed Changes To Personnel In A Hospital Medical Laboratory, Gerardo Morales

Theses and Dissertations - UTB/UTPA

A discrete event computer simulation is used to model a portion of the medical laboratory at Doctors Hospital at Renaissance in order to assess the current situation as well as to review the planed personnel changes. The area under observation is the section in which the processor(s) receive, label and distribute the patient samples. There are four cases modeled in the simulation: The main focus is to determine if one or two processors are needed per shift and if the high level of phone calls poses a significant delay to the processors’ workflow. The simulation results indicate that having two …

Inverse Synthetic Aperture Radar Imaging Theory And Application, Jaime Xavier Lopez

Theses and Dissertations - UTB/UTPA

Inverse Synthetic Aperture Radar (ISAR) is an electromagnetic sensing system that is capable of producing high resolution microwave images of moving targets. Despite being developed within the engineering community, the theory of radar imaging is a subject of tremendous mathematical richness. The theory of ISAR imaging alone is filled with many applications and open problems that the mathematician and physicist may find interesting. In this thesis, the basis for a filtered back projection imaging algorithm is derived from a popular scalar wave model. This imaging algorithm is based on a filtered-adjoint method for inverting ISAR data, and allows for the …

Benchmarking Bottom-Up And Top-Down Strategies To Sparql-To-Sql Query Translation, Andrii Kashliev

Theses and Dissertations - UTB/UTPA

Many researchers have proposed using conventional relational databases to store and query large Semantic Web datasets. The most complex component of this approach is SPARQL-to-SQL query translation. Existing algorithms perform this translation using either bottom-up or top-down strategy and result in semantically equivalent but syntactically different relational queries. Do relational query optimizers always produce identical query execution plans for semantically equivalent bottom-up and top-down queries? Which of the two strategies yields faster SQL queries? To address these questions, this work studies bottom-up and top-down translations of SPARQL queries with nested optional graph patterns. This work presents: (1) A basic graph …

Qualitative Analysis To A Nonlinear System, Pengcheng Xiao

Theses and Dissertations - UTB/UTPA

In this thesis, we first present a qualitative analysis to a nonlinear system under certain parametric conditions. Then for a special case, we make a series of variable transformation and apply the Prelle-Singer Method to find the first integrals of the simplified equations without complicated calculations. Through the inverse transformations we get the first integrals of the original equation. Finally, we use the same Prelle-Singer method to get the first integral for an extended nonlinear system.

Subdifferentials Of Distance Functions And Applications To Facility Location Problems, Juan Salinas Jr.

Theses and Dissertations - UTB/UTPA

The classical Heron problem states: on a given straight line in the plane, find a point C such that the sum of the distances from C to the given points A and B is minimal. This problem can be solved using standard geometry or differential calculus. In the light of modern convex analysis, we are able to investigate more general versions of this problem. In this thesis we propose and solve the following problem: on a given nonempty closed convex subset of IRs , find a point such that the sum of the distances from that point to n given …

Zero Inflated Exponential Distribution And It's Variants, Sougata Dhar

Theses and Dissertations - UTB/UTPA

There have been a lot of studies with respect to the popular Zero Inflated versions of some discrete distributions, like Zero Inflated Poisson and Zero Inflated Negative Binomial distributions. They arise naturally in the literature when one aims to model count data sets having more than usual number of zeros by well known probability distributions. But it can be argued and established that Zero Inflated versions of continuous distributions also make sense. In this thesis, we first provide some motivations for studying Zero Inflated versions of exponential distribution and its variants and then study some parametric and Bayesian aspects related …

Intractability Of Integration And Derivative For Multivariate Polynomial And Trigonometric Function, Liang Ding

Theses and Dissertations - UTB/UTPA

We study the hardness of some basic linear operators which involve high dimension integration or derivative. For a multivariate polynomial ��(��1, ⋯ , ����) which has format ∏ ∑ ��1, we show that there is no any factor polynomial time approximation for the integration of ��(��1, ⋯ , ����) in the unit cube [0,1] �� unless P = NP. In addition to polynomials, we extend the discussion to nonlinear function. For a trigonometric function ��(��1, ⋯ , ����) of format ∏ ∑ �������� ∗ , we show that it is #P-hard to compute derivative ����(��) (��1,⋯,����) ����1⋯������ at the origin …

Mathematics Of Synthetic Aperture Radar Imaging, Guillermo Garza

Theses and Dissertations - UTB/UTPA

In Synthetic Aperture Radar (SAR) imaging, radar antennas are mounted on an airborne platform. The scene to be imaged is illuminated by electromagnetic waves transmitted from an antenna. The goal is to extract information of the scene from the measurements taken of the scattered waves. Reconstructing an image of the scene is an inverse problem. In this thesis, we study a method of image reconstruction developed by formulating the data collected as a Fourier integral operator acting on the scene, then applying an approximate inverse operator to that data. In particular, we examine the effects of bistatic system geometry to …

Chemical Education Experiences From The English Language Learner Perspective, Annette Flores

Theses and Dissertations - UTB/UTPA

The Rio Grande Valley (RGV) is a region populated by Spanish-speaking immigrants and their descendants producing a large English Language Learner (ELL) student population. ELLs have historically had low literacy rates and achievement levels when compared to their counterparts. In order to address this achievement gap, previous research efforts and curriculum interventions have focused on language acquisition as being the determining factor in ELL education, with little attention given to academic content acquisition. More current research efforts have transitioned into English language acquisition through academic content instruction; this present research study specifically focuses on ELL experiences in chemistry. Participants were …

Collapsing Of Non Homogeneous Markov Chains, Agnish Dey

Theses and Dissertations - UTB/UTPA

In this thesis we have considered questions about lumpability of a non homogeneous markov chain. A number of results similar to those obtained in [2] in the case of homogeneous markov chains have been presented here. We have also considered a few results along the lines of those considered in [8].

Structural Basis For Sequence Specific Dna Binding And Protein Dimerization Of Hoxa13, Yonghong Zhang, Christine A. Larsen, H. Scott Stadler, James B. Ames

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

The homeobox gene (HOXA13) codes for a transcription factor protein that binds to AT-rich DNA sequences and controls expression of genes during embryonic morphogenesis. Here we present the NMR structure of HOXA13 homeodomain (A13DBD) bound to an 11-mer DNA duplex. A13DBD forms a dimer that binds to DNA with a dissociation constant of 7.5 nM. The A13DBD/DNA complex has a molar mass of 35 kDa consistent with two molecules of DNA bound at both ends of the A13DBD dimer. A13DBD contains an N-terminal arm (residues 324 - 329) that binds in the DNA minor groove, and a C-terminal helix (residues …

Investigating Students' Mental Models And Knowledge Construction Of Microscopic Friction. I. Implications For Curriculum Design And Development, Edgar D. Corpuz, N. Sanjay Rebello

Physics & Astronomy Faculty Publications

In this paper, we discuss the first phase of a multiphase study aimed at investigating the dynamics of students' knowledge construction in the context of unfamiliar physical phenomenon-microscopic friction. The first phase of this study involved the investigation of the variations in students' mental models of microscopic friction. Clinical interviews were conducted with 11 students enrolled in conceptual modern physics to elicit their ideas and generate themes of explanations. A phenomenographic approach of data analysis was employed to establish the variations in students' explanations. Results show that students' mental models of friction at the atomic level are dominated by their …

The Pan American (2011-07-14), Alma E. Hernandez, Roxann Garcia

UTPA Archives - The Pan American Newspaper

Vol. 67, No. 30

Artificial Lateral Line Canal For Hydrodynamic Detection, Yingchen Yang, Adrian Klein, Horst Bleckmann

Mechanical Engineering Faculty Publications

Fish use their lateral line system to detect minute water motions. The lateral line consists of superficial neuromasts and canal neuromasts. The response properties of canal neuromasts differ from those of superficial ones. Here, we report the design, fabrication, and characterization of an artificial lateral line canal system. The characterization was done under various fluid conditions, including dipolar excitation and turbulent flow. The experimental results with dipole excitation match well with a mathematical model. Canal sensors also demonstrate significantly better noise immunity compared with superficial ones. Canal-type artificial lateral lines may become important for underwater flow sensing.