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Articles 1 - 30 of 44
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Peakon, Pseudo-Peakon, And Cuspon Solutions For Two Generalized Camassa- Holm Equations, Jibin Li, Zhijun Qiao
Peakon, Pseudo-Peakon, And Cuspon Solutions For Two Generalized Camassa- Holm Equations, Jibin Li, Zhijun Qiao
School of Mathematical and Statistical Sciences Faculty Publications and Presentations
In this paper, we study peakon, cuspon, and pseudo-peakon solutions for two generalized Camassa-Holm equations. Based on the method of dynamical systems, the two generalized Camassa-Holm equations are shown to have the parametric representations of the solitary wave solutions such as peakon, cuspon, pseudo-peakons, and periodic cusp solutions. In particular, the pseudo-peakon solution is for the first time proposed in our paper. Moreover, when a traveling system has a singular straight line and a heteroclinic loop, under some parameter conditions, there must be peaked solitary wave solutions appearing.
Oxidation Of Dibenzothiophene To Dibenzothiophene Sulfone Using Tungsten (Vi) Oxide, Alejandrina Rivera
Oxidation Of Dibenzothiophene To Dibenzothiophene Sulfone Using Tungsten (Vi) Oxide, Alejandrina Rivera
Theses and Dissertations - UTB/UTPA
The oxidation of dibenzothiophene (DBT) to dibenzothiophene-sulfone has been considered as an alternate method to remove sulfur from crude oil. This study demonstrates that the oxidative desulfurization (ODS) of DBT to DBT-sulfone occurs using WO3 as a catalyst. WO3 was synthesized and characterized using X-ray diffraction to determine the phase of WO3. Each reaction was refluxed and run for four hours using WO3 as a catalyst, dibenzothiphene, and four different solvents: decahydronapthalene, n-dodecane, decalin, and dodecane. The reactions were performed at temperatures ranging from 120 oC to 150 oC. Aliquots were taken at 30 minutes for up to four hours …
An Integrated Multidisciplinary Nanoscience Concentration Certificate Program For Stem Education, Karen S. Martirosyan, Mikhail M. Bouniaev, Malik Rakhmanov, Ahmed Touhami, Nazmul Islam, Davood Askari, Tarek Trad, Dmitri Litvinov, Sergey E. Lyshevski
An Integrated Multidisciplinary Nanoscience Concentration Certificate Program For Stem Education, Karen S. Martirosyan, Mikhail M. Bouniaev, Malik Rakhmanov, Ahmed Touhami, Nazmul Islam, Davood Askari, Tarek Trad, Dmitri Litvinov, Sergey E. Lyshevski
Physics and Astronomy Faculty Publications and Presentations
Integration of nanoscience and nanotechnology curricula into the College of Science, Mathematics, and Technology (CSMT) at the University of Texas at Brownsville (UTB) is reported. The rationale for the established multidisciplinary Nanoscience Concentration Certificate Program (NCCP) is to: (i) develop nanotechnology-relevant courses within a comprehensive Science, Engineering and Technology curriculum, and, to offer students an opportunity to graduate with a certificate in nanoscience and nanotechnology; (ii) to contribute to students' success in achieving student outcomes across all college's majors, and, improve the breath, depth and quality of science, technology, engineering and mathematics (STEM) graduates' education; (iii) through NCCP, recruit certificate- …
Detection Of Pulsar Beams Deflected By The Black Hole In Sgr A*: Effects Of Black Hole Spin, Sourabh Nampalliwar, Richard H. Price, Teviet Creighton, Fredrick A. Jenet
Detection Of Pulsar Beams Deflected By The Black Hole In Sgr A*: Effects Of Black Hole Spin, Sourabh Nampalliwar, Richard H. Price, Teviet Creighton, Fredrick A. Jenet
Physics and Astronomy Faculty Publications and Presentations
Some Galactic models predict a significant population of radio pulsars close to the Galactic center. Beams from these pulsars could be strongly deflected by the supermassive black hole (SMBH) believed to reside at the Galactic center and as a result reach Earth. Earlier work assuming a Schwarzschild SMBH gave marginal chances of observing this exotic phenomenon with current telescopes and good chances with future telescopes. Here we study whether those estimates are significantly affected by SMBH spin. We find that spin effects make a negligible difference in detectability, but the pattern of pulse arrival times is clearly affected. In particular, …
Searching For Millisecond Pulsars: Surveys, Techniques And Prospects, Kevin Stovall, Duncan R. Lorimer, R. S. Lynch
Searching For Millisecond Pulsars: Surveys, Techniques And Prospects, Kevin Stovall, Duncan R. Lorimer, R. S. Lynch
Physics and Astronomy Faculty Publications and Presentations
Searches for millisecond pulsars (which we here loosely define as those with periods < 20 ms) in the galactic field have undergone a renaissance in the past five years. New or recently refurbished radio telescopes utilizing cooled receivers and state-of-the art digital data acquisition systems are carrying out surveys of the entire sky at a variety of radio frequencies. Targeted searches for millisecond pulsars in point sources identified by the Fermi Gamma-ray Space Telescope have proved phenomenally successful, with over 50 discoveries in the past five years. The current sample of millisecond pulsars now numbers almost 200 and, for the first time in 25 years, now outnumbers their counterparts in galactic globular clusters. While many of these searches are motivated to find pulsars which form part of pulsar timing arrays, a wide variety of interesting systems are now being found. Following a brief overview of the millisecond pulsar phenomenon, we describe these searches and present some of …
Nitroxide-Functionalized Graphene Oxide From Graphite Oxide, Yazmin I. Avila-Vega, Cesar C. Leyva-Porras, Marcela Mireles, Manuel Quevedo-Lopez, Javier Macossay-Torres, Jose Bonilla-Cruz
Nitroxide-Functionalized Graphene Oxide From Graphite Oxide, Yazmin I. Avila-Vega, Cesar C. Leyva-Porras, Marcela Mireles, Manuel Quevedo-Lopez, Javier Macossay-Torres, Jose Bonilla-Cruz
Chemistry Faculty Publications and Presentations
A facile method for preparing functionalized graphene oxide single layers with nitroxide groups is reported herein. Highly oxidized graphite oxide (GO=90.6%) was obtained, slightly modifying an improved Hummer’s method. Oxoammonium salts (OS) were investigated to introduce nitroxide groups to GO, resulting in a one-step functionalization and exfoliation. The mechanisms of functionalization/exfoliation are proposed, where the oxidation of aromatic alcohols to ketone groups, and the formation of alkoxyamine species are suggested. Two kinds of functionalized graphene oxide layers (GOFT1 and GOFT2) were obtained by controlling the amount of OS added. GOFT1 and GOFT2 exhibited a high interlayer spacing (d0001 = 1.12nm), …
The Effects Of A Red Tide, Karenia Brevis Episode On The Benthic Macroinvertebrate Communities Of South Padre Island, Texas, Liana Lerma
Theses and Dissertations - UTB/UTPA
South Padre Island, Texas has experienced increasing frequency of harmful algal blooms (Karenia brevis) since the 1900’s, many of which resulted in massive fishes kills. In addition, shorebirds and other terrestrial wildlife deaths have been linked to K. brevis blooms prompting investigations of potential pathways by which brevetoxins may be transmitted to higher trophic levels. The benthic macrofanual community inhabiting the swash zone of sandy beaches consists primarily of filter feeding invertebrates which may serve as toxin bioaccumulators to secondary consumers of both marine and terrestrial food webs. The first reported mass mortality of swash zone benthic macrofauna on the …
Optimal Control In The Treatment Of Retinitis Pigmentosa, Erika T. Camacho, Luis A. Melara, Cristina Villalobos, Stephen Wirkus
Optimal Control In The Treatment Of Retinitis Pigmentosa, Erika T. Camacho, Luis A. Melara, Cristina Villalobos, Stephen Wirkus
School of Mathematical and Statistical Sciences Faculty Publications and Presentations
Numerous therapies have been implemented in an effort to minimize the debilitating effects of the degenerative eye disease Retinitis Pigmentosa (RP), yet none have provided satisfactory long-term solution. To date there is no treatment that can halt the degeneration of photoreceptors. The recent discovery of the RdCVF protein has provided researchers with a potential therapy that could slow the secondary wave of cone death. In this work, we build on an existing mathematical model of photoreceptor interactions in the presence of RP and incorporate various treatment regiments via RdCVF. Our results show that an optimal control exists for the administration …
A Green Chemoselective And Practical Approach Toward N-(2-Azetidinonyl) 25-Disubstituted Pyrroles, Debasish Bandyopadhyay, Elvira Rhodes, Bimal K. Banik
A Green Chemoselective And Practical Approach Toward N-(2-Azetidinonyl) 25-Disubstituted Pyrroles, Debasish Bandyopadhyay, Elvira Rhodes, Bimal K. Banik
Chemistry Faculty Publications and Presentations
Pyrrole and 2-azetidinone are two essential heterocyclic scaffolds, which are being broadly used in medicinal chemistry and drug discovery field. A green and practical method to synthesize novel N-(2-azetidinonyl) 2,5-disubstituted pyrroles, which are comprised of both pyrrole and 2-azetidinone moieties, has been developed. The classical Paal–Knorr reaction is one of the simplest and most economical methods for the synthesis of biologically important and pharmacologically useful pyrrole derivatives. The present procedure for the synthesis of N-(2-azetidinonyl) 2,5-disubstituted pyrroles (1,2,5-trisubstituted pyrroles) has been accomplished by reacting 3-amino β-lactams and 2,5-hexanedione in the presence of bismuth nitrate pentahydrate as an ecofriendly …
Derivative Couplings And Analytic Gradients For Diabatic States, With An Implementation For Boys-Localized Configuration-Interaction Singles, Shervin Fatehi, Ethan Alguire, Joseph Subotnik
Derivative Couplings And Analytic Gradients For Diabatic States, With An Implementation For Boys-Localized Configuration-Interaction Singles, Shervin Fatehi, Ethan Alguire, Joseph Subotnik
Chemistry Faculty Publications and Presentations
We demonstrate that Boys-localized diabatic states do indeed exhibit small derivative couplings, as is required of quasidiabatic states. In doing so, we present a general formalism for calculating derivative couplings and analytic gradients for diabatic states. We then develop additional equations specific to the case of Boys-localized configuration-interaction singles (CIS)—in particular, the analytic gradient of the CIS dipole matrix—and we validate our implementation against finite-difference results. In a forthcoming paper, we will publish additional algorithmic and computational details and apply our method to the Closs energy-transfer systems as a further test of the validity of Boys-localized diabatic states.
Goals Strategies And First Discoveries Of Ao327 The Arecibo All-Sky 327 Mhz Drift Pulsar Survey, J. S. Deneva, K. Stovall, M. A. Mclaughlin, S. D. Bates, P. C.C. Freire, J. G. Martinez, F. Jenet, M. Bagchi
Goals Strategies And First Discoveries Of Ao327 The Arecibo All-Sky 327 Mhz Drift Pulsar Survey, J. S. Deneva, K. Stovall, M. A. Mclaughlin, S. D. Bates, P. C.C. Freire, J. G. Martinez, F. Jenet, M. Bagchi
Physics and Astronomy Faculty Publications and Presentations
We report initial results from AO327, a drift survey for pulsars with the Arecibo telescope at 327 MHz. The first phase of AO327 will cover the sky at declinations of -1° to 28°, excluding the region within 5° of the Galactic plane, where high scattering and dispersion make low-frequency surveys sub-optimal. We record data from a 57 MHz bandwidth with 1024 channels and 125 μs sampling time. The 60 s transit time through the AO327 beam means that the survey is sensitive to very tight relativistic binaries even with no acceleration searches. To date we have detected 44 known pulsars …
Cloning And Characterization Of Ef-Tu And Ef-Ts From Pseudomonas Aeruginosa, Stephanie O. Palmer, Edna Y. Rangel, Alberto E. Montalvo, Alexis T. Tran, Kate C. Ferguson, James M. Bullard
Cloning And Characterization Of Ef-Tu And Ef-Ts From Pseudomonas Aeruginosa, Stephanie O. Palmer, Edna Y. Rangel, Alberto E. Montalvo, Alexis T. Tran, Kate C. Ferguson, James M. Bullard
Chemistry Faculty Publications and Presentations
We have cloned genes encoding elongation factors We have cloned genes encoding elongation factors EF-Tu and EF-Ts from Pseudomonas aeruginosa and expressed and purified the proteins to greater than 95% homogeneity. Sequence analysis indicated that P. aeruginosa EF-Tu and EF-Ts are 84% and 55% identical to E. coli counterparts, respectively. P. aeruginosa EF-Tu was active when assayed in GDP exchange assays. Kinetic parameters for the interaction of EF-Tu with GDP in the absence of EF-Ts were observed to be = 33 μM, = 0.003 s−1, and the specificity constant was s−1 μM−1. In the presence of EF-Ts, these values were …
The Einstein@Home Search For Radio Pulsars And Psr J2007+2722 Discovery, B. Allen, B. Knispel, J. M. Cordes, J. S. Deneva, J. W.T. Hessels, D. Anderson, C. Aulbert, O. Bock, A. Brazier, S. Chatterjee, P. B. Demorest, H. B. Eggenstein, H. Fehrmann, E. V. Gotthelf, D. Hammer, V. M. Kaspi, M. Kramer, A. G. Lyne, B. Machenschalk, M. A. Mclaughlin, C. Messenger, H. J. Pletsch, S. M. Ransom, I. H. Stairs, B. W. Stappers, N. D.R. Bhat, S. Bogdanov, F. Camilo, D. J. Champion, F. Crawford
The Einstein@Home Search For Radio Pulsars And Psr J2007+2722 Discovery, B. Allen, B. Knispel, J. M. Cordes, J. S. Deneva, J. W.T. Hessels, D. Anderson, C. Aulbert, O. Bock, A. Brazier, S. Chatterjee, P. B. Demorest, H. B. Eggenstein, H. Fehrmann, E. V. Gotthelf, D. Hammer, V. M. Kaspi, M. Kramer, A. G. Lyne, B. Machenschalk, M. A. Mclaughlin, C. Messenger, H. J. Pletsch, S. M. Ransom, I. H. Stairs, B. W. Stappers, N. D.R. Bhat, S. Bogdanov, F. Camilo, D. J. Champion, F. Crawford
Physics and Astronomy Faculty Publications and Presentations
Einstein@Home aggregates the computer power of hundreds of thousands of volunteers from 193 countries, to search for new neutron stars using data from electromagnetic and gravitational-wave detectors. This paper presents a detailed description of the search for new radio pulsars using Pulsar ALFA survey data from the Arecibo Observatory. The enormous computing power allows this search to cover a new region of parameter space; it can detect pulsars in binary systems with orbital periods as short as 11 minutes. We also describe the first Einstein@Home discovery, the 40.8 Hz isolated pulsar PSR J2007+2722, and provide a full timing model. PSR …
Timing Of Favorable Conditions, Competition And Fertility Interact To Govern Recruitment Of Invasive Chinese Tallow Tree In Stressful Environments, Christopher A. Gabler, Evan Siemann
Timing Of Favorable Conditions, Competition And Fertility Interact To Govern Recruitment Of Invasive Chinese Tallow Tree In Stressful Environments, Christopher A. Gabler, Evan Siemann
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
The rate of new exotic recruitment following removal of adult invaders (reinvasion pressure) influences restoration outcomes and costs but is highly variable and poorly understood. We hypothesize that broad variation in average reinvasion pressure of Triadica sebifera (Chinese tallow tree, a major invader) arises from differences among habitats in spatiotemporal availability of realized recruitment windows. These windows are periods of variable duration long enough to permit establishment given local environmental conditions. We tested this hypothesis via a greenhouse mesocosm experiment that quantified how the duration of favorable moisture conditions prior to flood or drought stress (window duration), competition and nutrient …
Accuracy Analysis Of Parallel Method Based On Non-Overlapping Domain Decomposition Method, Moonho Tak, Yooseob Song, Hye-Kwan Jeon, Taehyo Park
Accuracy Analysis Of Parallel Method Based On Non-Overlapping Domain Decomposition Method, Moonho Tak, Yooseob Song, Hye-Kwan Jeon, Taehyo Park
Civil Engineering Faculty Publications and Presentations
In this paper, an accuracy analysis of parallel method based on non-overlapping domain decomposition method is carried out. In this approach, proposed by Tak et al.(2013), the decomposed subdomains do not overlap each other and the connection between adjacent subdomains is determined via simple connective finite element named interfacial element. This approach has two main advantages. The first is that a direct method such as gauss elimination is available even in a singular problem because the singular stiffness matrix from floating domain can be converted to invertible matrix by assembling the interfacial element. The second is that computational time and …
Algorithms In Abstract Dna Self Assembly, Xingsi Zhong
Algorithms In Abstract Dna Self Assembly, Xingsi Zhong
Theses and Dissertations - UTB/UTPA
For the past two years, I have always been working on the topic of Abstract DNA Tiles Self-Assembly. This is a very new area, driven by the interest of DNA molecules. The feature that the system composed by DNA molecules can be a highly parallelized system, make it much more powerful when comparing with the traditional methods. This thesis will introduce the concept of abstract DNA self-assembly models as well as some interesting problems and their solutions.
Synthetic Aperture Radar With Compressed Sensing, Yufeng Cao
Synthetic Aperture Radar With Compressed Sensing, Yufeng Cao
Theses and Dissertations - UTB/UTPA
A general synthetic aperture radar (SAR) signal model is derived from the Maxwell’s equations, and compressed sensing are introduced to the signal model for SAR image reconstruction. Random Partial Fourier Matrices were applied to prove that compressed sensing can be used to this signal model from the viewpoint of mathematics. In the numerical simulation part, we show that the procedure of basis pursuit can reconstruct SAR image, based on our main results, which is shown efficient in comparison with the matched filter algorithm.
Dynamical Behaviors Of Gonorrhea Strain Competition Model, Marisabel Rodriguez
Dynamical Behaviors Of Gonorrhea Strain Competition Model, Marisabel Rodriguez
Theses and Dissertations - UTB/UTPA
In the past decades, Gonorrhea, a sexually transmitted bacterial infection caused by Neisseria gonorrhoeae, has become resistant to a wider range of antibiotics. We apply a phenomenological model that takes into account essential ideas such as the effects of different treatment levels, the transformation and conjugation rates of bacteria, and the response of the immune system. Qualitative analysis provides a more integral view of how model parameters affect the emergence of within-host resistance.
Distributed Sparse Matrix Solver And Pivoting Algorithms For Large Linear Equations, Esteban Torres
Distributed Sparse Matrix Solver And Pivoting Algorithms For Large Linear Equations, Esteban Torres
Theses and Dissertations - UTB/UTPA
This thesis presents a distributed sparse direct solver and pivoting strategies for distributed sparse LU factorization. In Chapter I, we introduce some background concepts in linear algebra. In Chapter II, we discuss parallel hardware architectures and introduce our problem for discussion. In Chapter III, we describe the implementation of our sparse direct solver and our pivoting algorithms. Next, we present our simulation methodology and results in Chapter IV and we show that our pivoting algorithm yields up to 50% more accurate results than a current state-of-the-art solver, SuperLU_DIST. Finally, in Chapter V, we present some ideas to further improve the …
Timing And Interstellar Scattering Of 35 Distant Pulsars Discovered In The Palfa Survey, D. J. Nice, E. Altiere, S. Bogdanov, J. M. Cordes, D. Farrington, J. W.T. Hessels, V. M. Kaspi, A. G. Lyne, L. Popa, S. M. Ransom, S. Sanpa-Arsa, B. W. Stappers, Y. Wang, B. Allen, N. D.R. Bhat, A. Brazier, F. Camilo, D. J. Champion, S. Chatterjee, F. Crawford, J. S. Deneva, G. Desvignes, P. C.C. Freire, F. A. Jenet, B. Knispel, P. Lazarus, K. J. Lee, J. Van Leeuwen, D. R. Lorimer, R. Lynch
Timing And Interstellar Scattering Of 35 Distant Pulsars Discovered In The Palfa Survey, D. J. Nice, E. Altiere, S. Bogdanov, J. M. Cordes, D. Farrington, J. W.T. Hessels, V. M. Kaspi, A. G. Lyne, L. Popa, S. M. Ransom, S. Sanpa-Arsa, B. W. Stappers, Y. Wang, B. Allen, N. D.R. Bhat, A. Brazier, F. Camilo, D. J. Champion, S. Chatterjee, F. Crawford, J. S. Deneva, G. Desvignes, P. C.C. Freire, F. A. Jenet, B. Knispel, P. Lazarus, K. J. Lee, J. Van Leeuwen, D. R. Lorimer, R. Lynch
Physics and Astronomy Faculty Publications and Presentations
We have made extensive observations of 35 distant slow (non-recycled) pulsars discovered in the ongoing Arecibo PALFA pulsar survey. Timing observations of these pulsars over several years at Arecibo Observatory and Jodrell Bank Observatory have yielded high-precision positions and measurements of rotation properties. Despite being a relatively distant population, these pulsars have properties that mirror those of the previously known pulsar population. Many of the sources exhibit timing noise, and one underwent a small glitch. We have used multifrequency data to measure the interstellar scattering properties of these pulsars. We find scattering to be higher than predicted along some lines …
A Lover And A Fighter: The Genome Sequence Of An Entomopathogenic Nematode Heterorhabditis Bacteriophora, Xiaodong Bai, Byron J. Adams, Todd A. Ciche, Sandra Clifton, Randy Gaugler, Kwi-Suk Kim, Parwinder Grewal
A Lover And A Fighter: The Genome Sequence Of An Entomopathogenic Nematode Heterorhabditis Bacteriophora, Xiaodong Bai, Byron J. Adams, Todd A. Ciche, Sandra Clifton, Randy Gaugler, Kwi-Suk Kim, Parwinder Grewal
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
Heterorhabditis bacteriophora are entomopathogenic nematodes that have evolved a mutualism with Photorhabdus luminescens bacteria to function as highly virulent insect pathogens. The nematode provides a safe harbor for intestinal symbionts in soil and delivers the symbiotic bacteria into the insect blood. The symbiont provides virulence and toxins, metabolites essential for nematode reproduction, and antibiotic preservation of the insect cadaver. Approximately half of the 21,250 putative protein coding genes identified in the 77 Mbp high quality draft H. bacteriophora genome sequence were novel proteins of unknown function lacking homologs in Caenorhabditis elegans or any other sequenced organisms. Similarly, 317 of the …
Uso De Hábitat Y Perspectivas De Lontra Longicaudis En Un Área Protegida De Tamaulipas, México, Piedad Esther Mayagoitia-González, Alejandro Fierro-Cabo, Raul Valdez, Mark Andersen, David Cowley, Robert Steiner
Uso De Hábitat Y Perspectivas De Lontra Longicaudis En Un Área Protegida De Tamaulipas, México, Piedad Esther Mayagoitia-González, Alejandro Fierro-Cabo, Raul Valdez, Mark Andersen, David Cowley, Robert Steiner
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
El hábitat de la nutria neotropical (Lontra longicaudis) en el Área Natural Protegida (ANP) La Vega Escondida, ubicada al sur de Tamaulipas, se encuentra rodeado de un paisaje urbano en expansión. Los humedales en esta región están sometidos a una intensa presión debido a diversas actividades antropogénicas tales como la agricultura, ganadería y pesca comercial, así como construcciones y rellenos en orillas de laguna y río. El presente estudio tuvo como objetivos principales la evaluación y uso de hábitat de la nutria dentro del ANP La Vega Escondida, así como determinar la actitud de la población humana hacia esta especie. …
Study Of The Thermodynamics Of Chromium(Iii) And Chromium(Vi) Binding To Iron(Ii/Iii)Oxide Or Magnetite Or Ferrite And Magnanese(Ii) Iron (Iii) Oxide Or Jacobsite Or Manganese Ferrite Nanoparticles, Steven Luther, Nathan Brogfeld, Jisoo Kim, Jason Parsons
Study Of The Thermodynamics Of Chromium(Iii) And Chromium(Vi) Binding To Iron(Ii/Iii)Oxide Or Magnetite Or Ferrite And Magnanese(Ii) Iron (Iii) Oxide Or Jacobsite Or Manganese Ferrite Nanoparticles, Steven Luther, Nathan Brogfeld, Jisoo Kim, Jason Parsons
Chemistry Faculty Publications and Presentations
Removal of chromium(III) or (VI) from aqueous solution was achieved using Fe3O4, and MnFe2O4 nanomaterials. The nanomaterials were synthesized using a precipitation method and characterized using XRD. The size of the nanomaterials was determined to be 22.4±0.9 nm (Fe3O4) and 15.5±0.5 nm (MnFe2O4). The optimal binding pH for chromium(III) and chromium(VI) were pH 6 and pH 3. Isotherm studies were performed, under light and dark conditions, to determine the capacity of the nanomaterials. The capacities for the light studies with MnFe2O4 and Fe3O4 were determined to be 7.189 and 10.63 mg/g, respectively, for chromium(III). The capacities for the light studies …
Hydro-Thermal Convective Solutions For An Aquifer System Heated From Below, Dambaru Bhatta
Hydro-Thermal Convective Solutions For An Aquifer System Heated From Below, Dambaru Bhatta
School of Mathematical and Statistical Sciences Faculty Publications and Presentations
We investigate the effect of hydro-thermal convection in an aquifer system. It is assumed that the aquifer is bounded below and above by impermeable boundaries and it is heated from below. The solution of the governing system is expressed in terms of the basic steady state solution and perturbed solution. We obtain the critical Rayleigh number and critical wavenumber using Runge-Kutta method in combination of shooting method and present the marginal stability curve. The amplitude equation is derived by introducing the adjoint system. After amplitude is obtained, we compute the linear solutions for super-critical and sub-critical cases. Numerical results for …
Algebro-Geometric Solutions For The Degasperis--Procesi Hierarchy, Yu Hou, Peng Zhao, Engui Fan, Zhijun Qiao
Algebro-Geometric Solutions For The Degasperis--Procesi Hierarchy, Yu Hou, Peng Zhao, Engui Fan, Zhijun Qiao
School of Mathematical and Statistical Sciences Faculty Publications and Presentations
Though the completely integrable Camassa--Holm (CH) equation and Degasperis--Procesi (DP) equation are cast in the same peakon family, they possess the second- and third-order Lax operators, respectively. From the viewpoint of algebro-geometrical study, this difference lies in hyper-elliptic and non-hyper-elliptic curves. The non-hyper-elliptic curves lead to great difficulty in the construction of algebro-geometric solutions of the DP equation. In this paper, we derive the DP hierarchy with the help of Lenard recursion operators. Based on the characteristic polynomial of a Lax matrix for the DP hierarchy, we introduce a third order algebraic curve $\mathcal{K}_{r-2}$ with genus $r-2$, from which the …
Generalized Local Test For Local Extrema In Single-Variable Functions, Eleftherios Gkioulekas
Generalized Local Test For Local Extrema In Single-Variable Functions, Eleftherios Gkioulekas
School of Mathematical and Statistical Sciences Faculty Publications and Presentations
We give a detailed derivation of a generalization of the second derivative test of single-variable calculus which can classify critical points as local minima or local maxima (or neither), whenever the traditional second derivative test fails, by considering the values of higher-order derivatives evaluated at the critical points. The enhanced test is local, in the sense that it is only necessary to evaluate all relevant derivatives at the critical point itself, and it is reasonably robust. We illustrate an application of the generalized test on a trigonometric function where the second derivative test fails to classify some of the critical …
Biochemical, Nutrient And Inhibitory Characteristics Of Streptomyces Cultured From A Hypersaline Estuary, The Laguna Madre (Texas), Luis E. Espinoza, Anita L. Davelos Baines, Kristine L. Lowe
Biochemical, Nutrient And Inhibitory Characteristics Of Streptomyces Cultured From A Hypersaline Estuary, The Laguna Madre (Texas), Luis E. Espinoza, Anita L. Davelos Baines, Kristine L. Lowe
Biology Faculty Publications and Presentations
Streptomyces are common soil bacteria that produce secondary metabolites, including several antibiotics; however, the characteristics of marine Streptomyces are largely unknown. Sediment samples were taken from 3 sites in the Laguna Madre to isolate marine Streptomyces. Sediment was diluted, spread onto synthetic seawater media to estimate the total bacterial density of the samples and spread onto starch casein agar to isolate Streptomyces. Isolated Streptomyces were tested for salinity tolerance and optimal growth pH. Isolates were assayed using API 20E® test strips and BIOLOG™ plates to construct biochemical profiles and assess nutrient utilization abilities of the bacteria, respectively. Individual Streptomyces were …
Mathematical Modeling Of Two-Phase Arterial Blood Flow, Ani Emire Garcia Escorcia
Mathematical Modeling Of Two-Phase Arterial Blood Flow, Ani Emire Garcia Escorcia
Theses and Dissertations - UTB/UTPA
Problem of blood flow in an artery with or without catheter and in the presence of single or multi stenosis will be considered. The presence of stenosis locally thickens the artery wall and the use of catheter in the affected area is very important to the diagnostic and treatment of the patient. The blood flow in the arterial tube is represented by a two-phase model composing a suspension of erythrocytes in plasma. The governing equations for both fluid and particles are solved subjected to reasonable modeling and approximations. The important quantities such as blood speed, blood pressure force, impedance (blood …
Compressed Sensing For Multiple Input-Multiple Output Radar Imaging, Juan F. Lopez Jr.
Compressed Sensing For Multiple Input-Multiple Output Radar Imaging, Juan F. Lopez Jr.
Theses and Dissertations - UTB/UTPA
Multiple input - multiple output (MIMO) radar utilizes the transmission of spatially diverse waveforms from a static antenna array to gather information about the desired scene. We will demonstrate how techniques from compressed sensing can be applied to image formation in MIMO radar when in the presence of undersampling. We analyze the problem under the general theoretical framework of inverse scattering.
Nascent Nanocomputers: Dna Self-Assembly In O(1) Stages, Michael C. Barnes
Nascent Nanocomputers: Dna Self-Assembly In O(1) Stages, Michael C. Barnes
Theses and Dissertations - UTB/UTPA
DNA self-assembly offers a potential for nanoscale microcircuits and computers. To make that potential possible requires the development of reliable and efficient tile assembly models. Efficiency is often achieved by minimizing tile complexity, as well as by evaluating the cost and reliability of the specific elements of each tile assembly model. We consider a 2D tile assembly model at temperature 1. The standard 2D tile assembly model at temperature 1 has a tile complexity of O(n) for the construction of exact, complete n x n squares. However, previous research found a staged tile assembly model achieved a tile complexity of …