Physical Sciences and Mathematics Commons^™

Forced Oscillations Of The Korteweg-De Vries Equation On A Bounded Domain And Their Stability, Muhammad Usman, Bingyu Zhang

Mathematics Faculty Publications

It has been observed in laboratory experiments that when nonlinear dispersive waves are forced periodically from one end of undisturbed stretch of the medium of propagation, the signal eventually becomes temporally periodic at each spatial point. The observation has been confirmed mathematically in the context of the damped Kortewg-de Vries (KdV) equation and the damped Benjamin-Bona-Mahony (BBM) equation. In this paper we intend to show the same results hold for the pure KdV equation (without the damping terms) posed on a bounded domain. Consideration is given to the initial-boundary-value problem

uu_xu_xxx 0 < x < 1, t > 0, (*)

It is shown …

Stimuli-Responsive Hydrogel Microdomes Integrated With Genetically Engineered Proteins For High-Throughput Screening Of Pharmaceuticals, Sylvia Daunert, Sapna K. Deo, Jason Douglas Ehrick, Tyler William Browning, Leonidas G. Bachas

Chemistry Faculty Patents

A hydrogel microdome that can swell in response to a stimuli or target molecule is formed by polymerizing a mixture comprising a monomer capable of forming a hydrogel with a biopolymer. An array of hydrogel microdomes can be formed on a substrate by microspotting the mixture and polymerizing. The array can be used for high-throughput screening of analytes as well as for use as an actuator and biosensor using the swelling property of the hydrogel.

Recent Unprecedented Tree-Ring Growth In Bristlecone Pine At The Highest Elevations And Possible Causes, Matthew W. Salzer, Malcolm K. Hughes, Andrew G. Bunn, Kurt F. Kipfmueller

Andrew G. Bunn

Great Basin bristlecone pine (Pinus longaeva) at 3 sites in western North America near the upper elevation limit of tree growth showed ring growth in the second half of the 20th century that was greater than during any other 50-year period in the last 3,700 years. The accelerated growth is suggestive of an environmental change unprecedented in millennia. The high growth is not overestimated because of standardization techniques, and it is unlikely that it is a result of a change in tree growth form or that it is predominantly caused by CO2 fertilization. The growth surge has occurred only in …

Towards Reasoning Pragmatics, Pascal Hitzler

Computer Science and Engineering Faculty Publications

The realization of Semantic Web reasoning is central to substantiating the Semantic Web vision. However, current mainstream research on this topic faces serious challenges, which force us to question established lines of research and to rethink the underlying approaches.

Water Resources Year In Review - Winter 2009 Vol 21. No 2, Annis Water Resources Institute

AWRI Reviews

No abstract provided.

Are Periodic Solar Wind Number Density Structures Formed In The Solar Corona?, N. M. Viall, Harlan E. Spence, J. Kasper

Physics & Astronomy

[1] We present an analysis of the alpha to proton solar wind abundance ratio (AHe) during a period characterized by significant large size scale density fluctuations, focusing on an event in which the proton and alpha enhancements are anti-correlated. In a recent study using 11 years (1995–2005) of solar wind observations from the Wind spacecraft, N. M. Viall et al. [2008] showed that periodic proton density structures occurred at particular radial length-scales more often than others. The source of these periodic density structures is a significant and outstanding question. Are they generated in the interplanetary medium, or are they a …

Mathematics Teacher Educators As Cultural Workers: A Dare To Those Who Dare To Teach (Urban?) Teachers, David W. Stinson

Middle-Secondary Education and Instructional Technology Faculty Publications

In his editorial, the author challenges urban mathematics educators to institute as the primary goal for the community of mathematics educators the cultural transformation of the discipline of mathematics from the psychologically brutalizing discipline of stratification into the psychologically humanizing discipline of freedom.

Spatial Instability Of Electrically Driven Jets With Finite Conductivity And Under Constant Or Variable Applied Field, Saulo Orizaga, Daniel N. Riahi

Applications and Applied Mathematics: An International Journal (AAM)

We investigate the problem of spatial instability 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 of these modes is enhanced by the strength Ω of …

A Generalized Newton-Penalty Algorithm For Large Scale Ill-Conditioned Quadratic Problems, Maziar Salahi, Moslem Ganji

Applications and Applied Mathematics: An International Journal (AAM)

Large scale quadratic problems arise in many real world applications. It is quite often that the coefficient matrices in these problems are ill-conditioned. Thus, if the problem data are available even with small error, then solving them using classical algorithms might result to meaningless solutions. In this short paper, we propose an efficient generalized Newton-penalty algorithm for solving these problems. Our computational results show that our new simple algorithm is much faster and better than the approach of Rojas et al. (2000), which requires parameter tuning for different problems.

Some Applications Of The (G'/G)-Expansion Method For Solving The Nonlinear Partial Differential Equations In Mathematical Physics, Nasir Taghizade, Ahmad Neirameh

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we construct the traveling wave solutions involving parameters of the combined Kdv-MKdv equation, the Shorma-Tasso-Olver equation and (2+1)-dimensional Konopelchenko-Dubrovsky equation, by using a new approach method. When the parameters are taken special values, the solitary waves are derived from the traveling waves. The travelling wave solutions are expressed by the hyperbolic functions, the trigonometric functions and the rational functions.

Two-Layered Model Of Blood Flow Through Composite Stenosed Artery, Padma Joshi, Ashutosh Pathak, B. K. Joshi

Applications and Applied Mathematics: An International Journal (AAM)

In this paper a steady, axisymmetric flow, with a constricted tube has been studied. The artery has been represented by a two-layered model consisting of a core layer and a peripheral layer. It has been shown that the resistance to flow and wall shear stress increases as the peripheral layer viscosity increases. The results are compared graphically with those of previous investigators. It has been observed that the existence of peripheral layer is useful in representation of diseased arterial system.

Science-Technology Division News

Sci-Tech News

No abstract provided.

Sci-Tech Book News Reviews, Susan Fingerman

Sci-Tech News

No abstract provided.

Transition From N-Type To P-Type Destroys Ferromagnetism In Semiconducting Sn1-XCoXO2 And Sn1-XCrXO2 Nanoparticles, C. Van Komen, A. Punnoose, M. S. Seehra

Physics Faculty Publications and Presentations

This work reports strong correlations between the structural, magnetic and electronic properties of room temperature ferromagnets (RTFM) Sn_1-xCo_xO₂ and Sn_1-xCr_xO₂ for x = 0 to 0.1. The samples prepared by the sol-gel chemical method show RTFM for x < x_L with the limiting concentration x_L = 0.01 for Co doping and x_L = 0.025 for Cr doping. As doping level x is increased from x = 0, the magnetic moment per ion, μ, increases and the lattice volume V_L decreases up to _x = x_L. …

Morphology Of The Dayside Ionosphere Of Mars: Implications For Ion Outflows, Jane L. Fox

Physics Faculty Publications

Significant fluxes of tailward streaming ions have been detected in the Martian wake by instruments on spacecraft. Imposing outward fluxes at the top of a model will produce dayside ion density profiles that are characterized by smaller scale heights than those of diffusive equilibrium. We determine the maximum outward fluxes of ions, and those implied by radio occultation data, by constructing ∼180 models, with upward velocity boundary conditions in the range from 0 to (7–8) × 10⁵ cm s⁻¹ in small increments. As the upward velocity is increased, the topside ion or electron densities decrease until eventually the …

Review Of The Evidence Used In The Description Of Currently Recognized Cetacean Subspecies, William F. Perrin, James G. Mead, Robert L. Brownell Jr.

United States Department of Commerce: Staff Publications

We reviewed the subspecies listed by Rice (1998) and those described since (a total of 49, in 19 species), assessing them against the criteria recommended by the recent Workshop on Shortcomings of Cetacean Taxonomy in Relation to Needs of Conservation and Management (Reeves et al., 2004). The workshop suggested that the subspecies concept can be construed to cover two types of entities: a) lineages diverging but not quite far along the continuum of divergence (still having significant gene flow with another lineage or lineages) to be judged as species, and b) lineages that may well be species but for which …

Geometry Of Control-Affine Systems, Jeanne N. Clelland, Christopher G. Moseley, George R. Wilkens

University Faculty Publications and Creative Works

Motivated by control-affine systems in optimal control theory, we introduce the notion of a point-affine distribution on a manifold X - i.e., an affine distribution F together with a distinguished vector field contained in F. We compute local invariants for point-affine distributions of constant type when dim(X) = n, rank(F) = n - 1, and when dim(X) = 3, rank(F) = 1. Unlike linear distributions, which are characterized by integer- valued invariants - namely, the rank and growth vector - when dim(X) ≤ 4, we find local invariants depending on arbitrary functions even for rank 1 point-affine distributions on manifolds …

Branchings And Time Evolution Of Reaction Networks, Changyuan Wang

All Dissertations

In this thesis I analyze flows in reaction networks in terms of branchings
in a digraph. If the coupled differential equations governing the rate
of change of probabilities X of a state or species are finite-differenced in time, a matrix equation (I + Adt)X(t+dt) = X(t) results, where X(t) is a vector giving the probabilities at time t and X(t+dt) is a vector giving the probabilities at time t + dt. I demonstrate that the matrix (I + Adt) may be written as the product of an incidence matrix and a weight matrix for a directed graph (digraph) representing the …

Exploring Formation And Distribution Of Halonitromethanes In Drinking Waters, Jia Hu

All Dissertations

ABSTRACT
Nine halonitromethanes (HNMs) were among the more than fifty unregulated high-priority disinfection by-products (DBPs) that were monitored for and detected in drinking waters in a 2000-2002 nationwide occurrence study funded by the US Environmental Protection Agency (USEPA). The toxicology studies conducted in recent years have shown that HNMs are one of the most cytotoxic and genotoxic classes among the emerging DBPs, with orders of magnitude higher cytotoxicity and genotoxicity than any of the regulated organic DBPs. Furthermore, brominated HNMs were found to be more toxic than their chlorinated analogs, with dibromonitromethane being the most cyto- and genotoxic. Today, our …

Metal Oxide And Mercuric Sulfide Nanoparticles Synthesis And Characterization, Xin Xu

All Dissertations

Increasing applications of nanoparticles (NPs), such as metal oxide and mercuric sulfide NPs, lead to heightened environmental concern. Challenges to the study of natural and engineered NPs include the physical and chemical characterizations.
Commercially available and laboratory-synthesized metal based NPs, iron oxide (Fe2O3), copper oxide (CuO), titanium dioxide (TiO2), zinc oxide (ZnO) and mercuric sulfide (HgS) were studied by comprehensive characterizations methods. The general synthesis process was modified sol-gel method. The size and morphology of NPs could be influenced by temperature, sonication, calcination, precursor concentration, pH and types of reaction media. In the synthesis of nZnO in ethanol, the essential …

Synthesis And Characterization Of Metallic, Core-Shell And Composite Nanoparticles, Amar Kumbhar

All Dissertations

ABSTRACT
Silver nanoparticles exhibit size, shape and the surrounding dielectric medium dependent optical properties (scattering and absorption) in the visible spectral region. These optical properties can be explained in terms of the collective oscillation of the 'free conduction band electrons' or 'surface plasmons' induced by an external electromagnetic field. Dipole and Quadrupole Plasmon resonances have been observed for silver particles less than 100nm in diameter prepared using various synthetic techniques. However higher order resonances have been elusive due to lack of experimental techniques to prepare colloidal solutions of large silver nanoparticles in the size range above 100nm. Controlled hydrogen reduction …

Development Of A Fluorescent Probe For Determination Of Water Transport In Subcellular Organelles, Adriana Chaurra-Arboleda

All Dissertations

Water transport has been widely studied in a variety of cells and isolated membranes. However, the intrinsic complexity related with the study of intracellular processes has delayed the development of an analytical technique for the study of water transport in subcellular compartments of living cells. This study represents the development and application of a ratiometric fluorescent probe to study water transport in endocytic organelles of intact living cells. The probe is based on the use of a D₂O-sensitive fluorophore, Lucifer yellow dextran (LY-dex), together with a D₂O-insensitive fluorophore, Alexa fluor 546 dextran (AF546-dex), used as an …

An Approach Designed For Reginal Prospective Human Health And Ecological Risk Assessment And Its Application To Mercury Risks From A Coal-Fired Power Plant, Pathratipa Sansayavichai

All Dissertations

A large and/or long-term released source of a toxic chemical(s) can cause adverse effects to humans and non–human species inhabiting all over the region. The overall goal of this dissertation was to improve practices in risk assessment concerning a regional risk posed by a prospective source. A generic conceptual framework for performing regional prospective human health and ecological risk assessment was developed. The formulation of a priori considerations was used to identify the possible sources of uncertainties in the prospective risk assessment. Physiologically based pharmacokinetic (PBPK) modeling was utilized to reduce uncertainty in a toxicologically safe dose used in risk …

Polymeric Carbon Nanocomposites - Preparation, Characterization, And Properties, Lucia Veca

All Dissertations

Excellent thermal properties of carbon nanomaterials such as carbon nanotubes and newly discovered graphene make them the filler of choice for the development of thermal management materials. Graphene has been viewed as “ unrolled single-walled carbon nanotube and as a wonder material with many superlatives to its name ” thus there is an excessive interest in developing new synthetic routes towards large scale production of high quality graphene nanosheets.
In this dissertation, we report different methods that could further exfoliate the commercially available expanded graphite to nanometer sized carbon structures, “carbon nanosheets ”, for their use in highly thermal conductive …

Functional Characterization Of Calcium Dependent Protein Kinase 32 From Arabidopsis, Rucha Karve

All Dissertations

Calcium-dependent protein kinases (CPKs) are major plant Ca2+ sensors, many of which have roles in plant stress responses. The Arabidopsis genome encodes 34 CPK isoforms. Here we report characterization of AtCPK32 gene function. Analysis of transgenic plants expressing pCPK32-GUS shows that CPK32 is highly expressed in roots, pollen and embryo, as well as leaf hydathodes, and the abscission zone of mature siliques. Real time RT-PCR and promoter expression patterns show that CPK32 is responsive to abiotic and biotic stresses. Plants treated with salt, ABA, osmotic stress (PEG), wounding, and flagellin 22 peptide show up-regulation of CPK32 upon these stress treatments. …

Atom Scattering From Metals, William Hayes

All Dissertations

In the initial portion of this dissertation studies of Ar
scattering from Ru(0001) at thermal and hyperthermal energies are
compared to calculations with classical scattering theory. These
data exhibited a number of characteristics that are unusual in
comparison to other systems for which atomic beam experiments have
been carried out under similar conditions. The measured energy
losses were unusually small. Some of the angular distributions
exhibited an anomalous shoulder feature in addition to a broad
peak near the specular direction and quantum mechanical
diffraction was observed under conditions for which it was not
expected. Many of the unusual features observed …

Synthesis And Development Of Novel Fullerene-Based Structures For Photovoltaics, Electronic Applications And Mri Contrast Agents, Manuel Chaur

All Dissertations

Metallic nitride endohedral metallofullerenes (EMFs) are one of the most interesting types of metallofullerenes due to their high yields and interesting electronic properties. The synthesis of these compounds allows the encapsulation of different metals inside fullerenes making it possible to combine the properties of the metal with those of the fullerene. Their interesting electrochemical and optical features make them potential candidates for several applications such as molecular electronics, biomedical imaging, non-linear optical devices, and magnetic resonance imaging (MRI) agents. This thesis reports the synthesis of novel metallic nitride EMFs based on Gd, Nd, Pr, Ce and La. These families of …

Some New Problems In Changepoint Analysis, Jonathan Woody

All Dissertations

Climatological studies have often neglected changepoint effects when modeling
various physical phenomena. Here, changepoints are plausible whenever a station location moves or its instruments are changed. There is frequently meta-data to
perform sound statistical inferences that account for changepoint
information. This dissertation focuses on two such problems in changepoint analysis.
The first problem we investigate involves assessing trends
in daily snow depth series. Here, we introduce a stochastic storage model. The model allows for seasonal features, which permits the
analysis of daily data. Changepoint times are shown to greatly influence estimated trends in one snow depth series and are accounted …

On The Testing And Estimation Of High-Dimensional Covariance Matrices, Thomas Fisher

All Dissertations

Many applications of modern science involve a large number of parameters. In
many cases, the number of parameters, p, exceeds the number of observations,
N. Classical multivariate statistics are based on the assumption that the
number of parameters is fixed and the number of observations is large. Many of
the classical techniques perform poorly, or are degenerate, in high-dimensional
situations.
In this work, we discuss and develop statistical methods for inference of
data in which the number of parameters exceeds the number of observations.
Specifically we look at the problems of hypothesis testing regarding and the
estimation of the covariance …

Decoding Of Multipoint Algebraic Geometry Codes Via Lists, Nathan Drake

All Dissertations

Algebraic geometry codes have been studied greatly since their introduction by Goppa . Early study had focused on algebraic geometry codes CL(D;G) where G was taken to be a multiple of a single point. However, it has been shown that if we allow G to be supported by more points, then the associated code may have better parameters. We call such a code a multipoint code and if G is supported by m points, then we call it an m-point code. In this dissertation, we wish to develop a decoding algorithm for multipoint codes. We show how we can embed …