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University of Texas Rio Grande Valley

2010

Articles 1 - 30 of 51

Full-Text Articles in Physical Sciences and Mathematics

Due Diligence And Demographic Disparities: Effects Of The Planning Of U.S.- Mexico Border Fence On Marginalized Populations, J. Gaines Wilson, Jude A. Benavides, Karen Engle, Denise Gilman, Anthony Reisinger, Jessica Spangler, Joe Lemen Dec 2010

Due Diligence And Demographic Disparities: Effects Of The Planning Of U.S.- Mexico Border Fence On Marginalized Populations, J. Gaines Wilson, Jude A. Benavides, Karen Engle, Denise Gilman, Anthony Reisinger, Jessica Spangler, Joe Lemen

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

In the buildup to the construction the U.S.-Mexico border fence by the United States Department of Homeland Security (USDHS), much attention was drawn to security, drug enforcement, and immigration issues. However, there was little quantitative analysis regarding which populations were most likely to be affected by the proposed fence. Using a geographic information system, we classified census blocks in Cameron County, Texas into one of two categories: either ‘fence’ or ‘gap’. A total of 14 demographic factors were tested for disparities between those living in gap areas and those living in areas exposed to the fence. Twelve of fourteen factors …

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Equation Of State Of A Dense And Magnetized Fermion System, Efrain J. Ferrer, Vivian De La Incera, Jason P. Keith, Israel Portillo, Paul L. Springsteen Dec 2010

Equation Of State Of A Dense And Magnetized Fermion System, Efrain J. Ferrer, Vivian De La Incera, Jason P. Keith, Israel Portillo, Paul L. Springsteen

Physics and Astronomy Faculty Publications and Presentations

The equation of state of a system of fermions in a uniform magnetic field is obtained in terms of the thermodynamic quantities of the theory by using functional methods. It is shown that the breaking of the O(3) rotational symmetry by the magnetic field results in a pressure anisotropy, which leads to the distinction between longitudinal- and transverse-to-the-field pressures. A criterion to find the threshold field at which the asymmetric regime becomes significant is discussed. This threshold magnetic field is shown to be the same as the one required for the pure field contribution to the energy and pressures to …

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Double Compact Objects As Low-Frequency Gravitational Wave Sources, Krzysztof Belczynski, Matthew Benacquista, Tomasz Bulik Dec 2010

Double Compact Objects As Low-Frequency Gravitational Wave Sources, Krzysztof Belczynski, Matthew Benacquista, Tomasz Bulik

Physics and Astronomy Faculty Publications and Presentations

We study the Galactic field population of double compact objects (DCOs; NS-NS, BH-NS, BH-BH binaries) to investigate the number (if any) of these systems that can potentially be detected with the Laser Interferometer Space Antenna (LISA) at low gravitational wave frequencies. We calculate the Galactic numbers and physical properties of these binaries and show their relative contributions from the disk, bulge, and halo. Although the Galaxy hosts ∼10 5 DCO binaries emitting low-frequency gravitational waves, only a handful of these objects in the disk will be detectable with LISA, but none from the halo or bulge. This is because the …

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Spectral Reflectance As An Indicator Of Foliar Concentrations Of Arsenic In Common Sunflower (Helianthus Annuus), Yuridia Patricia Peralta De Gandy Dec 2010

Spectral Reflectance As An Indicator Of Foliar Concentrations Of Arsenic In Common Sunflower (Helianthus Annuus), Yuridia Patricia Peralta De Gandy

Theses and Dissertations - UTB/UTPA

Studies were conducted to investigate the use of spectral reflectance by foliage of common sunflower as a potential indicator of arsenic contamination of soil. Germination method was developed for sunflower seeds, and cohorts of sunflower seedlings in hydroponic tanks were established. The cohorts were exposed to 0 ppm, 5 ppm, 7.5 ppm, and 10 ppm treatments of As (V) and reflectance measurements of foliage were collected using a spectroradiometer during two experiments.Results demonstrated the feasibility of using spectral reflectance by foliage of common sunflower as a potential indicator of arsenic contamination. In both experiments, arsenic concentrations in leaf tissues were …

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A Highly Efficient Bismuth Salts-Catalyzed Route For The Synthesis Of Alpha-Aminophosphonates, Antara Banik, Sahil Batta, Debasish Bandyopadhyay, Bimal K. Banik Nov 2010

A Highly Efficient Bismuth Salts-Catalyzed Route For The Synthesis Of Alpha-Aminophosphonates, Antara Banik, Sahil Batta, Debasish Bandyopadhyay, Bimal K. Banik

Chemistry Faculty Publications and Presentations

A convenient synthesis of different types of α-amino phosphonates via one-pot solvent-free three component reactions of aldehydes, amines and phosphites catalyzed by bismuth salts has been investigated. Bismuth triflate is found to be the most effective catalyst for this reaction.

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Importance Of Electronic Relaxation For Inter-Coulombic Decay In Aqueous Systems, Craig P. Schwartz, Shervin Fatehi, Richard J. Saykally, David Prendergast Nov 2010

Importance Of Electronic Relaxation For Inter-Coulombic Decay In Aqueous Systems, Craig P. Schwartz, Shervin Fatehi, Richard J. Saykally, David Prendergast

Chemistry Faculty Publications and Presentations

Inspired by recent photoelectron spectroscopy experiments on hydroxide solutions, we have examined the conditions necessary for enhanced (and, in the case of solutions, detectable) inter-Coulombic decay (ICD)—Auger emission from an atomic site other than that originally excited. We present general guidelines, based on energetic and spatial overlap of molecular orbitals, for this enhancement of inter-Coulombic decay-based energy transfer in solutions. These guidelines indicate that this decay process should be exhibited by broad classes of biomolecules and suggest a design criterion for targeted radiooncology protocols. Our findings show that photoelectron spectroscopy cannot resolve the current hydroxide coordination controversy.

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First Search For Gravitational Waves From The Youngest Known Neutron Star, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, M. Araya, M. Aronsson, Y. Aso, S. Aston, D. E. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, S. Ballmer, D. Barker, S. Barnum, B. Barr, P. Barriga, L. Barsotti, M. A. Barton Oct 2010

First Search For Gravitational Waves From The Youngest Known Neutron Star, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, M. Araya, M. Aronsson, Y. Aso, S. Aston, D. E. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, S. Ballmer, D. Barker, S. Barnum, B. Barr, P. Barriga, L. Barsotti, M. A. Barton

Physics and Astronomy Faculty Publications and Presentations

We present a search for periodic gravitational waves from the neutron star in the supernova remnant Cassiopeia A. The search coherently analyzes data in a 12 day interval taken from the fifth science run of the Laser Interferometer Gravitational-Wave Observatory. It searches gravitational-wave frequencies from 100 to 300 Hz and covers a wide range of first and second frequency derivatives appropriate for the age of the remnant and for different spin-down mechanisms. No gravitational-wave signal was detected. Within the range of search frequencies, we set 95% confidence upper limits of (0.7-1.2) × 10 -24 on the intrinsic gravitational-wave strain, (0.4-4) …

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Ultra-Compact Dwarfs In The Core Of The Coma Cluster, Juan P. Madrid, Alister W. Graham, William E. Harris, Paul Goudfrooij, Duncan A. Forbes, David Carter, John P. Blakeslee, Lee R. Spitler, Henry C. Ferguson Oct 2010

Ultra-Compact Dwarfs In The Core Of The Coma Cluster, Juan P. Madrid, Alister W. Graham, William E. Harris, Paul Goudfrooij, Duncan A. Forbes, David Carter, John P. Blakeslee, Lee R. Spitler, Henry C. Ferguson

Physics and Astronomy Faculty Publications and Presentations

We have discovered both a red and a blue subpopulation of ultra-compact dwarf (UCD) galaxy candidates in the Coma galaxy cluster. We analyzed deep F475W (Sloan g) and F814W (I) Hubble Space Telescope images obtained with the Advanced Camera for Surveys Wide Field Channel as part of the Coma Cluster Treasury Survey and have fitted the light profiles of similar to 5000 point-like sources in the vicinity of NGC 4874, one of the two central dominant galaxies of the Coma Cluster. Although almost all of these sources are globular clusters that remain unresolved, we found that 52 objects have effective …

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Detecting Massive Gravitons Using Pulsar Timing Arrays, Kejia Lee, F. A. Jenet, Richard H. Price, Norbert Wex, Michael Kramer Oct 2010

Detecting Massive Gravitons Using Pulsar Timing Arrays, Kejia Lee, F. A. Jenet, Richard H. Price, Norbert Wex, Michael Kramer

Physics and Astronomy Faculty Publications and Presentations

At the limit of weak static fields, general relativity becomes Newtonian gravity with a potential field that falls off as inverse distance rather than a theory of Yukawa-type fields with a finite range. General relativity also predicts that the speed of disturbances of its waves is c, the vacuum light speed, and is non-dispersive. For these reasons, the graviton, the boson for general relativity, can be considered to be massless. Massive gravitons, however, are features of some alternatives to general relativity. This has motivated experiments and observations that, so far, have been consistent with the zero-mass graviton of general relativity, …

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Dissipation Scales And Anomalous Sinks In Steady Two-Dimensional Turbulence, Eleftherios Gkioulekas Oct 2010

Dissipation Scales And Anomalous Sinks In Steady Two-Dimensional Turbulence, Eleftherios Gkioulekas

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In previous papers I have argued that the fusion rules hypothesis, which was originally introduced by L’vov and Procaccia in the context of the problem of three-dimensional turbulence, can be used to gain a deeper insight in understanding the enstrophy cascade and inverse energy cascade of two-dimensional turbulence. In the present paper, we show that the fusion rules hypothesis, combined with nonperturbative locality, itself a consequence of the fusion rules hypothesis, dictates the location of the boundary separating the inertial range from the dissipation range. In so doing, the hypothesis that there may be an anomalous enstrophy sink …

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Molecular Mechanisms Of Persistence Of Mutualistic Bacteria Photorhabdus In The Entomopathogenic Nematode Host, Ruisheng An, Parwinder Grewal Oct 2010

Molecular Mechanisms Of Persistence Of Mutualistic Bacteria Photorhabdus In The Entomopathogenic Nematode Host, Ruisheng An, Parwinder Grewal

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

Symbioses between microbes and animals are ubiquitous, yet little is known about the intricate mechanisms maintaining such associations. In an emerging mutualistic model system, insect-pathogenic bacteria Photorhabdus and their insect-parasitic nematode partner Heterorhabditis, we found that the bacteria undergo major transcriptional reshaping in the nematode intestine. Besides general starvation mechanisms, the bacteria induce cellular acidification to slow down growth, switch to pentose phosphate pathway to overcome oxidative stress and nutrition limitation, and shed motility but develop biofilm to persist in the nematode intestine until being released into the insect hemolymph. These findings demonstrate how the symbiotic bacteria reduce their …

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The Sensitivity Of The Parkes Pulsar Timing Array To Individual Sources Of Gravitational Waves, D. R.B. Yardley, G. B. Hobbs, F. A. Jenet, J. P.W. Verbiest, Z. L. Wen, R. N. Manchester, W. A. Coles, W. Van Straten, M. Bailes, N. D.R. Bhat, S. Burke-Spolaor, D. J. Champion, A. W. Hotan, J. M. Sarkissian Sep 2010

The Sensitivity Of The Parkes Pulsar Timing Array To Individual Sources Of Gravitational Waves, D. R.B. Yardley, G. B. Hobbs, F. A. Jenet, J. P.W. Verbiest, Z. L. Wen, R. N. Manchester, W. A. Coles, W. Van Straten, M. Bailes, N. D.R. Bhat, S. Burke-Spolaor, D. J. Champion, A. W. Hotan, J. M. Sarkissian

Physics and Astronomy Faculty Publications and Presentations

We present the sensitivity of the Parkes Pulsar Timing Array to gravitational waves (GWs) emitted by individual supermassive black hole binary systems in the early phases of coalescing at the cores of merged galaxies. Our analysis includes a detailed study of the effects of fitting a pulsar timing model to non-white timing residuals. Pulsar timing is sensitive at nanoHertz frequencies and hence complementary to Laser Interferometer Gravitational-Wave Observatory and Laser Interferometer Space Antenna. We place a sky-averaged constraint on the merger rate of nearby (z < 0.6) black hole binaries in the early phases of coalescence with a chirp mass of 1010 M⊙ of less than one merger every 7 yr. The prospects for future GW astronomy of this type with the proposed Square Kilometre Array telescope are discussed. © 2010 The Authors. Journal compilation © 2010 RAS.

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Compact Binaries In Star Clusters - I. Black Hole Binaries Inside Globular Clusters, J. M.B. Downing, M. J. Benacquista, M. Giersz, R. Spurzem Sep 2010

Compact Binaries In Star Clusters - I. Black Hole Binaries Inside Globular Clusters, J. M.B. Downing, M. J. Benacquista, M. Giersz, R. Spurzem

Physics and Astronomy Faculty Publications and Presentations

We study the compact binary population in star clusters, focusing on binaries containing black holes, using a self-consistent Monte Carlo treatment of dynamics and full stellar evolution. We find that the black holes experience strong mass segregation and become centrally concentrated. In the core the black holes interact strongly with each other and black hole-black hole binaries are formed very efficiently. The strong interactions, however, also destroy or eject the black hole-black hole binaries. We find no black hole-black hole mergers within our simulations but produce many hard escapers that will merge in the Galactic field within a Hubble time. …

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Multi-Soliton Solutions To A Model Equation For Shallow Water Waves, Zhijiang Qiao Aug 2010

Multi-Soliton Solutions To A Model Equation For Shallow Water Waves, Zhijiang Qiao

Theses and Dissertations - UTB/UTPA

In Soliton theory, Hirota direct method is most efficient tool for seeking one soliton solutions or multi-soliton solutions of integrable nonlinear partial differential equations. The key step of the Hirota direct method is to transform the given equation into its Hirota bilinear form. Once the bilinear form of the given equation is found, we can construct the soliton and multi-soliton solutions of that model. Many interesting characteristics of Pfaffians were discovered through studies of soliton equations. In this thesis, a shallow water wave model and its bilinear equation are investigated. Using Hirota direct method, we obtain the multi-soliton solutions and …

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Distributed Storage And Queryng Techniques For A Semantic Web Of Scientific Workflow Provenance, Jaime Alberto Navarro Aug 2010

Distributed Storage And Queryng Techniques For A Semantic Web Of Scientific Workflow Provenance, Jaime Alberto Navarro

Theses and Dissertations - UTB/UTPA

In scientific workflow environments, scientists depend on provenance, which records the history of an experiment. Resource Description Framework is frequently used to represent provenance based on vocabularies such as the Open Provenance Model. For complex scientific workflows that generate large amounts of RDF triples, single-machine provenance management becomes inadequate over time. In this thesis, we research how HBase capabilities can be leveraged for distributed storage and querying of provenance data represented in RDF. We architect the ProvBase system that incorporates an HBase/Hadoop backend, propose a storage schema to hold provenance triples, and design querying algorithms to evaluate SPARQL queries in …

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Identification Of Parameters And The Distribution Of The Maximum And The Minimum, Lijuan Bi Aug 2010

Identification Of Parameters And The Distribution Of The Maximum And The Minimum, Lijuan Bi

Theses and Dissertations - UTB/UTPA

In problems of competing risks, where an individual may be subject to m causes of death and X(i) is the lifetime of an individual exposed to the ith cause, the X(i)s are not observable but only is their minimum, and inference is needed on the X(i) based on their minimum. The same is the case with a m-component system, where the components are connected in series, and we are interested in inference on the lifetimes of the individual components. These examples motivate problems on parameter identification by the distribution of the minimum. Similarly, the example of a m-component system where …

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Study On Energy Absorption Behaviors Of Hydrophobic Mesoporous Materials, Zhongyuan Sun Aug 2010

Study On Energy Absorption Behaviors Of Hydrophobic Mesoporous Materials, Zhongyuan Sun

Theses and Dissertations - UTB/UTPA

Nanoporous energy absorption system has been developed tremendously as an advanced energy storage system in recent years. This research is to optimize the mesoporous energy absorption matrixes via surface treatment to find out the optimum conditions for higher energy conversion efficiency. Five mesoporous silica matrixes with pore size in a range of 3 to 31.6 nm were investigated. Six alkylchlorosilanes were used as the modification reagents. The results showed that the energy absorption density via pressure-induced infiltration is as high as 8.0 J/g which is 100 times larger than that of conventional energy absorption materials. The controllability of the energy …

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New Algorithms For Protein Structure Comparison And Protein Structure Prediction, Zaixin Lu Jul 2010

New Algorithms For Protein Structure Comparison And Protein Structure Prediction, Zaixin Lu

Theses and Dissertations - UTB/UTPA

Proteins show a great variety of 3D conformations, which can be used to infer their evolutionary relationship and to classify them into more general groups; therefore algorithms of protein structure alignment, protein similarity search and protein structure prediction are very helpful for protein biologists. We developed new algorithms for the problems in this field. The algorithms are tested with structures from the Protein Data Bank (PDB) and SCOP, a Structure Classification of Protein Database. The experimental results show that our tools are more efficient than some well known systems for finding similar protein structures and predicting protein structures.

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Algorithmic Temperature 1 Self-Assembly, Yunhui Fu Jul 2010

Algorithmic Temperature 1 Self-Assembly, Yunhui Fu

Theses and Dissertations - UTB/UTPA

We investigate the power of the Wang tile self-assembly model at temperature 1, a threshold value that permits attachment between any two tiles that share even a single bond. When restricted to deterministic assembly in the plane, no temperature 1 assembly system has been shown to build a shape with a tile complexity smaller than the diameter of the shape. Our work shows a sharp contrast in achievable tile complexity at temperature 1 if either growth into the third dimension or a small probability of error are permitted. Motivated by applications in nanotechnology and molecular computing, and the plausibility of …

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Apo B100 Similarities To Viral Proteins Suggest Basis For Ldl-Dna Binding And Transfection Capacity, Juan Guevara, Nagindra Prashad, Boris Ermolinsky, John W. Gaubatz, Dongcheul Kang, Andrea E. Schwarzbach, David S. Loose, Natalia Valentinova Guevara Jul 2010

Apo B100 Similarities To Viral Proteins Suggest Basis For Ldl-Dna Binding And Transfection Capacity, Juan Guevara, Nagindra Prashad, Boris Ermolinsky, John W. Gaubatz, Dongcheul Kang, Andrea E. Schwarzbach, David S. Loose, Natalia Valentinova Guevara

Physics and Astronomy Faculty Publications and Presentations

LDL mediates transfection with plasmid DNA in a variety of cell types in vitro and in several tissues in vivo in the rat. The transfection capacity of LDL is based on apo B100, as arginine/lysine clusters, suggestive of nucleic acid-binding domains and nuclear localization signal sequences, are present throughout the molecule. Apo E may also contribute to this capacity because of its similarity to the Dengue virus capsid proteins and its ability to bind DNA. Synthetic peptides representing two apo B100 regions with prominent Arg/Lys clusters were shown to bind DNA. Region 1 (0014Lys-Ser 0160) shares sequence motifs present in …

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Duffing-Van Der Pol Type Oscillator, Guangyue Gao Jul 2010

Duffing-Van Der Pol Type Oscillator, Guangyue Gao

Theses and Dissertations - UTB/UTPA

The nonlinear Duffing-van der Pol oscillator system is studied by means of the Lie symmetry reduction method and the Preller-Singer method. With the particular case of coefficients, this system has physical relevance as a simple model in certain flow-induced structural vibration problems. Under certain parametric conditions, we are concerned with the first integrals of the Duffing-van der Pol oscillator system. After making a series of variable transformations, we apply the Preller-Singer method and the Lie symmetry reduction method to obtain the first integrals of the simplified equations without complicated calculations.

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Modeling Instabilities Of Electrically Driven Jets With Finite Conductivity Under Constant Or Variable Applied Field, Saulo I. Orizaga Jul 2010

Modeling Instabilities Of Electrically Driven Jets With Finite Conductivity Under Constant Or Variable Applied Field, Saulo I. Orizaga

Theses and Dissertations - UTB/UTPA

We investigate the problem of spatial (S), combined spatial and temporal (CST), and non-linear temporal instability (NLT) of electrically driven viscous jets with finite electrical conductivity and in the presence of either a constant or a variable applied electric field. A mathematical model, which is developed and used for the spatially growing disturbances in electrically driven jet flows, leads to a lengthy equation for the unknown growth rate and frequency of the disturbances. This equation is solved numerically using Newton‟s Method. For neutral temporal stability boundary, we find, in particular, two new spatial modes of instability under certain conditions. One …

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Soliton Solutions To Integrable Equations, Haiqi Wang Jul 2010

Soliton Solutions To Integrable Equations, Haiqi Wang

Theses and Dissertations - UTB/UTPA

In recent years, integrable systems and soliton theory play an important role in the study of nonlinear water wave equations. In this thesis, we will focus on the procedure of how to get soliton solutions for integrable equations. The fundamental idea is to use the traveling wave setting to convert a partial differential equation to an ordinary differential equation and to solve ordinary differential equations yields soliton solutions for the integrable equations under certain boundary conditions at both negative and positive infinities. In our work, we will consider five integrable equations and present their solitons solutions, one of which will …

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An Effective Microwave-Induced Iodine-Catalyzed Method For The Synthesis Of Quinoxalines Via Condensation Of 12-Diamines With 12-Dicarbonyl Compounds, Debasish Bandyopadhyay, Sanghamitra Mukherjee, Robert R. Rodriguez, Bimal K. Banik Jun 2010

An Effective Microwave-Induced Iodine-Catalyzed Method For The Synthesis Of Quinoxalines Via Condensation Of 12-Diamines With 12-Dicarbonyl Compounds, Debasish Bandyopadhyay, Sanghamitra Mukherjee, Robert R. Rodriguez, Bimal K. Banik

Chemistry Faculty Publications and Presentations

A microwave-induced iodine-catalyzed simple, rapid and convenient synthesis of different types of quinoxalines via condensation of 1,2-diamines with 1,2-dicarbonyl compounds has been accomplished with an excellent yield.

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Parameterized Algorithm For 3-Sat, Yi Gao May 2010

Parameterized Algorithm For 3-Sat, Yi Gao

Theses and Dissertations - UTB/UTPA

The SAT problem is the classical NP-complete problem. In the past, many methods have been proposed for solving this problem. We investigated a new method for 3-SAT problem, which is a fixed parameterized algorithm proposed in this paper first. This method uses a fixed parameter k, where k is the number of true values in an assignment for checking whether the formula is satisfied or not. The complexity of our algorithm is O(3k ), which is exponentially independent of the number of variables. Theoretical analysis shows that when k is small, this method has smaller search space and higher speed.

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Genotyping Of Tgif Polymorphisms Associated With Schizophrenia And Psychosis, George Vera Jr. May 2010

Genotyping Of Tgif Polymorphisms Associated With Schizophrenia And Psychosis, George Vera Jr.

Theses and Dissertations - UTB/UTPA

Polymorphisms in Transforming Growth β-Induced Factor (TGIF) have been found to contribute to the risk of development of psychosis and related disorders. Identifying the genes responsible for causing schizophrenia and psychosis will allow for treatment at an earlier stage of development, saving the patient problems, time, and money. The purpose of this experiment is to determine the haplotype of DNA samples obtained from earlier experiments. The DNA samples were collected from people with schizophrenia in Costa Rica, Southern Texas, and Northern Mexico. The samples were tested using 5 single nucleotide polymorphisms (SNPs) and amplified using polymerase chain reaction (PCR). Haplotypes …

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Dna Staged Self-Assembly At Temperature 1, Nicholas H. Guiterrez May 2010

Dna Staged Self-Assembly At Temperature 1, Nicholas H. Guiterrez

Theses and Dissertations - UTB/UTPA

We introduce alternate temperature 1 self-assembly constructions of an n x n square by efficiently utilizing bins and stages to achieve desirable results. These bins are able to contain a variety of tiles or supertiles, which are then mixed together in a pre-determined sequence of distinct stages. The basic 2D tile assembly model at temperature 1 uses 2n-1 tile types to construct a square. The model only utilizes one bin and occurs all in one stage. We will demonstrate how the use of bins and stages will allow for the construction of these squares more efficiently.

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A Synthetic Approach Toward Novel Β-Lactams, Mohamed Hashim May 2010

A Synthetic Approach Toward Novel Β-Lactams, Mohamed Hashim

Theses and Dissertations - UTB/UTPA

β-lactam antibiotics which is a class by itself, covers a wide range of antibiotics that includes penicillin, penicillin derivatives, cephalosporins, carbapenems, and any antibiotic agent that contains a 2-azetidinone ring.[2] In recent past research it has been established that β-lactams show therapeutic and anticancer activity with low toxicity. [2] It has also been reported by our lab that N-chrysenyl and N-phenanthrenyl 3-acetoxy-4-aryl-2- azetidinone can exhibit potent selective anticancer activity towards prostate, colon, pancreatic cancer and leukemia at low concentrations, all of this was revealed by means of a structure activity study. [2] The goal of our research is the synthesis …

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Trace Analysis Of Volatile Organic Compounds In The Water Of The Arroyo Colorado And The Lower Laguna Madre Utilizing E.P.A.Sw846 Method 8260, Humberto Valdez May 2010

Trace Analysis Of Volatile Organic Compounds In The Water Of The Arroyo Colorado And The Lower Laguna Madre Utilizing E.P.A.Sw846 Method 8260, Humberto Valdez

Theses and Dissertations - UTB/UTPA

Volatile organic compounds (VOC) can cause a major environmental concern since they create a hazard to public health and the environment. This study focused on determining concentration of VOCs in Arroyo Colorado waters and the Lower Laguna Madre (LLM) utilizing GC/MS. Little is known on the concentration and composition of VOCs. Toluene was the most common VOC. Concentrations ranged from 0.0010 mg/L to 0.0039 mg/L. Analysis of a sediment pore water sample collected near the mouth of the Arroyo Colorado also detected toluene (0.0023 mg/L). This study showed that VOCs were concentrated near the county boat launch and somewhat downstream. …

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A Proposal For The Mechanism Of The Iron-Ascorbate, Fenton, And Hydroxyl Radical-Quenching Series, Jonathan Velasco May 2010

A Proposal For The Mechanism Of The Iron-Ascorbate, Fenton, And Hydroxyl Radical-Quenching Series, Jonathan Velasco

Theses and Dissertations - UTB/UTPA

The Fenton reaction between [Fe(II)] and [HOOH] is observed in the presence of ascorbic acid, [AscH-], during [Fe(III)] and HO• reduction; this is done as part of consecutive redox reactions between [Fe(III)] and [Fe(II)]. As a result, the rate orders with respect to [Fe(III)], ascorbic acid, and [HOOH] are of (approximately) 2nd, 1st, and 4 th order, respectively. However, the rate constants for each reaction in this study show patterns when measured against solution pH; empirically, reactions proceed faster at smaller pH and vice versa.

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