Physical Sciences and Mathematics Commons^™

Arctic Perennial Ice Cover Over The Last 14 Million Years, Dennis A. Darby

OES Faculty Publications

Knowledge of the long-term history of the perennial ice is an important issue that has eluded study because the Cenozoic core material needed has been unavailable until the recent Arctic Coring Expedition (ACEX). Detrital Fe oxide mineral grains analyzed by microprobe from the last 14 Ma (164 m) of the ACEX composite core on the Lomonosov Ridge were matched to circum-Arctic sources with the same mineral and 12-element composition. These precise source determinations and estimates of drift rates were used to determine that these sand grains could not be rafted to the ACEX core site in less than a year. …

Actively Engaging Pre-Service Teachers In Geometry And Measurement, Kadian M. Callahan

Proceedings of the Annual Meeting of the Georgia Association of Mathematics Teacher Educators

Current work in mathematics education suggests that the learning experiences in which teachers engage during undergraduate study influences their knowledge of and beliefs about mathematics and the ways in which they will teach (Allen, et. al., 2008; CBMS, 2001; Hill, Rowan, & Ball, 2005; National Research Council, 2001). However, very little is known about pre-service teachers’ learning experiences and how those experiences influence their thinking about mathematics teaching and learning. The classroom excerpt described here attempts to illuminate how pre-service, elementary teachers’ active engagement in the learning of geometry and measurement influences their mathematical power: a positive disposition toward mathematics, …

Covert Encryption And Document Authentication Using Texture Coding, Jonathan Blackledge, Mary Hallot

Articles

With the improvements in the quality of Commercial-Off-The-Shelf (COTS) printing and scanning devices, the ability to counterfeit documents has become a widespread problem. Consequently, there has been an increasing demand to develop digital watermarking techniques which can be applied to both electronic and printed images (and documents) that can be authenticated, prevent unauthorized copying and withstand abuse and degradation. In this paper , a new approach to digital watermarking is presented and a range of possible applications are considered. The process is defined by using concepts and techniques borrowed from Cryptography. It is based on computing a 'scramble image' by …

Multi-Algorithmic Cryptography Using Deterministic Chaos With Applications To Mobile Communications, Jonathan Blackledge

Articles

In this extended paper, we present an overview of the principal issues associated with cryptography, providing historically significant examples for illustrative purposes as part of a short tutorial for readers that are not familiar with the subject matter. This is used to introduce the role that nonlinear dynamics and chaos play in the design of encryption engines which utilize different types of Iteration Function Systems (IFS). The design of such encryption engines requires that they conform to the principles associated with diffusion and confusion for generating ciphers that are of a maximum entropy type. For this reason, the role of …

Object Detection And Classification With Applications To Skin Cancer Screening, Jonathan Blackledge, Dmitryi Dubovitskiy

Articles

This paper discusses a new approach to the processes of object detection, recognition and classification in a digital image. The classification method is based on the application of a set of features which include fractal parameters such as the Lacunarity and Fractal Dimension. Thus, the approach used, incorporates the characterisation of an object in terms of its texture.

The principal issues associated with object recognition are presented which includes two novel fast segmentation algorithms for which C++ code is provided. The self-learning procedure for designing a decision making engine using fuzzy logic and membership function theory is also presented and …

A Photometric Redshift Of Z = 1.8+0.4 -.3 For The Agile Grb 080514b, A. Rossi, A. De Ugarte Postigo, P. Ferrero, D. A. Kann, S. Klose, S. Schulze, J. Greiner, P. Schady, R. Filgas, E. E. Gonsalves, A. Küpcü Yolda¸S, T. Krühler, G. Szokoly, A. Yolda¸S, P. M.J. Afonso, C. Clemens, J. S. Bloom, D. A. Perley, J. P.U. Fynbo, A. J. Castro-Tirado, J. Gorosabel, P. Kubánek, Adria Updike, D. H. Hartmann, A. Giuliani, S. T. Holland, L. Hanlon, M. Bremer, J. French, G. Melady, D. A. García-Hernández

Arts & Sciences Faculty Publications

The AGILE gamma-ray burst GRB 080514B is the first detected to have emission above 30 MeV and an optical afterglow. However, no spectroscopic redshift for this burst is known.We report on our ground-based optical/NIR and millimeter follow-up observations of this event at several observatories, including the multi-channel imager GROND on La Silla, supplemented by Swift UVOT and Swift XRT data. The spectral energy distribution (SED) of the optical/NIR afterglow is found to decline sharply bluewards to the UV bands, which can be utilized in estimating the redshift. Fitting the SED from the Swift UVOT uvw2 band to the H band, …

The Rapidly Flaring Afterglow Of The Very Bright And Energetic Grb 070125, Adria Updike, Josh B. Haislip, Melissa C. Nysewander, Andrew S. Fruchter, D. Alexander Kann, Sylvio Klose, Peter A. Milne, G. Grant Williams, Weikang Zheng, Carl W. Hergenrother, Jason X. Prochaska, Jules P. Halpern, Nestor Mirabal, John R. Thorstensen, Alexander J. Van Der Horst, Rhaana L.C. Starling, Judith L. Racusin, David N. Burrows, N. P.M. Kuin, Peter W.A. Roming, Eric Bellm, Kevin Hurley, Weidong Li, Alexei V. Filippenko, Cullen Blake, Dan Starr, Emilio E. Falco, Warren R. Brown, Xinyu Dai, Jinsong Deng, Liping Xin, Yulei Qiu, Jianyan Wei, Yuji Urata, Domenico Nanni, Elisabetta Maiorano, Eliana Palazzi, Guiseppe Greco, Corrado Bartolini, Adriano Guarnieri, Adalberto Piccioni, Graziella Pizzichini, Federica Terra, Kuntal Misra, B. C. Bhatt, G. C. Anupama, X. Fan, L. Jiang, Ralph A.M.J. Wijers, Daniel E. Reichart, Hala A. Eid, Ginger Bryngelson, Jason Puls, R. C. Goldthwaite, Dieter H. Hartmann

Arts & Sciences Faculty Publications

No abstract provided.

Multiwavelength Analysis Of The Intriguing Grb 061126: The Reverse Shock Scenario And Magnetization, A. Gomboc, S. Kobayashi, C. Guidorzi, A. Melandri, V. Mangano, B. Sbarufatti, C. G. Mundell, P. Schady, R. J. Smith, Adria Updike, D. A. Kann, K. Misra, E. Rol, A. Pozanenko, A. J. Castro-Tirado, G. C. Anupama, D. Bersier, M. F. Bode, D. Carter, P. Curran, A. Fruchter, J. Graham, D. H. Hartmann, M. Ibrahimov, A. Levan, A. Monfardini, C. J. Mottram, P. T. O’Brien, P. Prema, D. K. Sahu, I. A. Steele, N. R. Tanvir, K. Wiersema

Arts & Sciences Faculty Publications

No abstract provided.

A Visual Indication Of Environmental Humidity Using A Color Changing Hologram Recorded In A Self-Developing Photopolymer, Izabela Naydenova, Raghavendra Jallapuram, Vincent Toal, Suzanne Martin

Articles

A reflection hologram for visual indication of environmental humidity has been studied. The hologram is recorded in a self-developing photopolymer and changes color when exposed to a change in humidity and is fully reversible. The range of color change, reversibility, and the response time of the hologram have been studied in a controlled humidity environment. Fully reversible holograms with response times from few seconds to tens of minutes have been designed. Extremely sensitive bright visual humidity indicators, capable of dramatic color change within a few seconds of breathing on them are demonstrated

Method For Characterization Of Diffusion Properties Of Photopolymerisable Systems, Tzvetanka Babeva, Izabela Naydenova, Suzanne Martin, Vincent Toal

Articles

A novel approach for measuring the diffusion coefficients in photopolymerisable materials is proposed. The method is based on studying the evolution of the surface relief profile in a single illuminated spot using an interferometric surface profiler. It is shown that the observed post-exposure swelling in the illuminated spot is due to mass-transport of monomer from the unexposed to the exposed area driven by a monomer concentration gradient set up by the monomer polymerization in the exposed area. Appropriate choice of the thickness of the studied layers ensures both lateral movement of monomer and negligible contribution from the depth. The diffusion …

Implementation Of Phase-Only Modulation Utilizing A Twisted Nematic Liquid Crystal Spatial Light Modulator, Mohammad Mahmud, Izabela Naydenova, Vincent Toal

Articles

Twisted nematic liquid crystal spatial light modulators, (SLM) are widely used for amplitude modulation of light. The technique for measuring phase and amplitude modulation introduced by a twisted nematic cell is not new but the novelty here is that after characterisation of a Holoeye LC2002 TNLC device we were able to identify specific conditions that allow for its use as a pure 180 degree or more, phase modulator with little or no amplitude modulation at 514.5 nm laser wavelength. The phase shift introduced by the SLM was measured using a Mach-Zehnder interferometer. The experimentally measured and the theoretically predicted intensity …

Investigation Of The Ground State Features Of Some Excotic Nuclei By Using Effective Skyrme Interaction, Hüseyi̇n Ayteki̇n, Eyyüp Tel, Ridvan Baldik

Turkish Journal of Physics

Nuclear many-body system is usually described through a mean-field built upon a nucleon-nucleon effective interaction. This interaction has been developed over the years for both stable and unstable nuclei as precise spectroscopic data has been built up. In this study, the proton and neutron densities, charge densities, root mean square (rms) nuclear charge radii, rms nuclear mass radii, rms nuclear proton and neutron radii, and neutron skin thickness were calculated for the neutron-rich Ni, Kr and Sn isotopes by the Hartree-Fock method with an effective Skyrme force based on nucleon-nucleon interactions known as SI, SIII, SVI, T3, SKM and SKM^*. …

Fractional Poisson Bracket, Alireza Khalili Golmankhaneh

Turkish Journal of Physics

In the present paper fractional Hamilton-Jacobi equation has been derived for dynamical systems involving the Caputo derivative. Fractional Poisson-bracket is introduced. Further Hamilton's canonical equations are formulated and quantum wave equation corresponds to the fractional Hamilton-Jacobi equation is suggested. Illustrative examples have been worked out to explain the formalism.

Path Integral Quantization Of Spinning Superparticle, Hanaa A. Elegla, N. I. Farahat

Turkish Journal of Physics

The Hamilton-Jacobi formalism is used to discuss the path integral quantization of a spinning superparticle model. The equations of motion are obtained as total differential equations in many variables. The equations of motion are integrable, and the path integral is obtained as an integration over the canonical phase space coordinates.

Computational Study Of Vibrational Dynamics Of Binary Mg_{0.70}Zn_{0.30} Metallic Glass By A Pseudopotential Theory, Aditya M. Vora

Turkish Journal of Physics

The vibrational dynamics of Mg_{70}Zn_{30} metallic glass has been studied at room temperature in terms of phonon eigen-frequencies of longitudinal and transverse modes employing three different approaches proposed by Hubbard-Beeby (HB), Takeno-Goda (TG) and Bhatia-Singh (BS). The well-recognized model potential is employed successfully to explain electron-ion interaction in the metallic glass; instead of using experimental values of the pair correlation function g(r), which is generated from the computed pair potential. The present findings of phonon dispersion curve are found in fair agreement with available theoretical as well as experimental data. The thermodynamic properties obtained by HB and TG approaches are …

Rigidity And Stability For Isometry Groups In Hyperbolic 4-Space, Youngju Kim

Dissertations, Theses, and Capstone Projects

It is known that a geometrically finite Kleinian group is quasiconformally stable. We prove that this quasiconformal stability cannot be generalized in 4-dimensional hyperbolic space. This is due to the presence of screw parabolic isometries in dimension 4. These isometries are topologically conjugate to strictly parabolic isometries. However, we show that screw parabolic isometries are not quasiconformally conjugate to strictly parabolic isometries. In addition, we show that two screw parabolic isometries are generically not quasiconformally conjugate to each other. We also give some geometric properties of a hyperbolic 4-manifold related to screw parabolic isometries.

A Fuchsian thrice-punctured sphere group has …

Biological Networks: Modeling And Structural Analysis, Emad Y. Ramadan

Computer Science Theses & Dissertations

Biological networks are receiving increased attention due to their importance in understanding life at the cellular level. There exist many different kinds of biological networks, and different models have been proposed for them. In this dissertation we focus on suitable network models for representing experimental data on protein interaction networks and protein complex networks (protein complexes are groups of proteins that associate to accomplish some function in the cell), and to design algorithms for exploring such networks. Our goal is to enable biologists to identify the general principles that govern the organization of protein-protein interaction networks and protein complex networks. …

On The Impact Of Winter Conditions On The Dynamics Of An Isolated Population, Lev V. Nedorezov, E. V. Volkova, Alexandr M. Sadykov

All Peer-Reviewed Publications

This chapter is devoted to the analysis of single-species population dynamics models with overlapping and non-overlapping generations. Within the framework of all models it is assumed that there are no activities of individuals during the wintertime (as, for example, is the case for forest insect populations in the boreal zone), and changes in population size at these moments are described with a broken trajectory (“jump down”). Also, it is assumed that the fecundity of individuals is constant and that the quota of individuals surviving winter depends on the within-year population dynamics. The dynamics of the models, which are determined by …

Shear Wave Splitting And Mantle Flow Associated With The Deflected Pacific Slab Beneath Northeast Asia, Kelly H. Liu, Stephen S. Gao, Yuan Gao, Jing Wu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A total of 361 SKS and five local S wave splitting measurements obtained at global and regional seismic network stations in NE China and Mongolia are used to infer the characteristics of mantle fabrics beneath northeast Asia. Fast polarization directions at most of the stations in the western part of the study area are found to be consistent with the strike of local geological features. The dominant fast directions at the eastern part, beneath which seismic tomography and receiver function studies revealed a deflected slab in the mantle transition zone (MTZ), are about 100° from north, which are almost exactly …

Light Vector Mesons In The Nuclear Medium, M. H. Wood, M. J. Amaryan, H. Bagdasaryan, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, H. G. Juengst, N. Kalantarians, A. Klein, K. V. Klimenko, S. E. Kuhn, J. Lachniet, M. R. Niroula, R. A. Niyazov, S. Tkachenko, L. B. Weinstein, J. Zhang, Clas Collaboration

Physics Faculty Publications

The light vector mesons (ρ,ω, and ϕ) were produced in deuterium, carbon, titanium, and iron targets in a search for possible in-medium modifications to the properties of the ρ meson at normal nuclear densities and zero temperature. The vector mesons were detected with the CEBAF Large Acceptance Spectrometer (CLAS) via their decays to e+e−. The rare leptonic decay was chosen to reduce final-state interactions. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing technique. The ρ-meson mass spectrum was extracted after the ω and ϕ signals were removed in a nearly model-independent way. Comparisons …

Electroexcitation Of The Roper Resonance For 1.7 < Q² < 4.5gev² In Ep → Enπ+, Clas Collaboration, M. J. Amaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, G. Gavalian, N. Guler, C. E. Hyde, A. Klein, S. E. Kuhn, L. M. Qin, L. B. Weinstein, J. Yun, J. Zhang

Physics Faculty Publications

The helicity amplitudes of the electroexcitation of the Roper resonance are extracted for 1.7 < Q² < 4.5 GeV² from recent high precision JLab-CLAS cross section and longitudinally polarized beam asymmetry data for π⁺ electroproduction on protons at W=1.15-1.69 GeV. The analysis is made using two approaches, dispersion relations and a unitary isobar model, which give consistent Q² behavior of the helicity amplitudes for the gamma*p -> N (1440)P₁₁ transition. It is found that the transverse helicity amplitude A _1/2, which is large and negative at Q²=0, becomes large and positive at Q² similar or equal …

First Measurement Of Target And Double Spin Asymmetries For Ep → Epπ° In The Nucleon Resonance Region Above The Δ (1232), Clas Collaborative, M. J. Amaryan, H. Bagdasaryan, S. Bültmann, G. E. Dodge, N. Guler, N. Kalantarians, A. Klein, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, J. Zhang

Physics Faculty Publications

The exclusive channel polarized proton(polarized e,e' p)π⁰ was studied in the first and second nucleon resonance regions in the Q² range from 0.187 to 0.770 GeV² at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). Longitudinal target and beam-target asymmetries were extracted over a large range of center-of-mass angles of the π⁰ and compared to the unitary isobar model MAID, the dynamic model by Sato and Lee, and the dynamic model DMT. A strong sensitivity to individual models was observed, in particular for the target asymmetry and in the higher invariant mass region. This data …

Electroproduction Of ɸ(1020) Mesons At 1.4 ≤ Q² ≤ 3.8 Gev² Measured With The Clas Spectrometer, Clas Collaboration, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, C. E. Hyde-Wright, H. G. Jungst, N. Kalantarians, A. Klien, A. V. Klimenko, S. E. Kuhn, R. A. Niyazov, T. Tkachenko, L. B. Weinstein, J. Zhang

Physics Faculty Publications

Electroproduction of exclusive ϕ vector mesons has been studied with the CLAS detector in the kinematic range 1.4 ⩽ Q² ⩽ 3.8 GeV² ,0.0 ⩽ t′ ⩽3.6 GeV² , and 2.0 ⩽ W ⩽ 3.0 GeV. The scaling exponent for the total cross section as 1/(Q² +M²_ϕ)ⁿ was determined to be n = 2.49 ± 0.33. The slope of the four-momentum transfer t′ distribution is b_ϕ = 0.98 ± 0.17 GeV^-2 . Under the assumption of s -channel helicity conservation, we determine the ratio of longitudinal to transverse cross sections …

Measurement Of Deeply Virtual Compton Scattering Beam-Spin Asymmetries, Clas Collaboration, H. Bagdasaryan, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, C. E. Hyde, H. G. Juengst, N. Kalantarians, A. Klein, A. V. Klimenko, S. E. Kuhn, J. Lachniet, S. Tkachenko, L. B. Weinstein, J. Zhang

Physics Faculty Publications

The beam-spin asymmetries in the hard exclusive electroproduction of photons on the proton (^→ep→epγ ) were measured over a wide kinematic range and with high statistical accuracy. These asymmetries result from the interference of the Bethe-Heitler process and of deeply virtual Compton scattering. Over the whole kinematic range (_xB from 0.11 to 0.58, Q² from 1 to 4.8  GeV², −t from 0.09 to 1.8  GeV²), the azimuthal dependence of the asymmetries is compatible with expectations from leading-twist dominance, A ≃ asinϕ/(1+ccosϕ). This extensive set of data can thus be used to …

Cross Sections And Beam Asymmetries For E ⃗ P → Enπ+ In The Nucleon Resonance Region For 1.7 ⩽ Q2 ⩽ 4.5 Gev2, M. J. Amaryan, H. Bagdasaryan, S. Bültmann, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, A. V. Klimenko, S. E. Kuhn, J. Lachniet, R. A. Niyazov, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

The exclusive electroproduction process e ⃗ p → e'nπ⁺ was measured in the range of the photon virtuality Q² =1.7-4.5 GeV², and the invariant mass range for the n π⁺ system of W=1.15-1.7 GeV using the CEBAF Large Acceptance Spectrometer. For the first time, these kinematics are probed in exclusive π⁺ production from protons with nearly full coverage in the azimuthal and polar angles of the nπ⁺ center-of-mass system. The nπ⁺ channel has particular sensitivity to the isospin 1/2 excited nucleon states, and together with the pπ⁰ final state will serve …

Ratios Of 15N/12C And 4He/12C Inclusive Electroproduction Cross Sections In The Nucleon Resonance Region, P. E. Bosted, R. Fersch, G. Adams, M. Amaryan, S. Anefalos, M. Anghinolfi, G. Asryan, H. Avakian, H. Badasaryan, N. Baillie, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. E. Dodge, K. V. Dharmawardane, T. A. Forest, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, J. Lachniet, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Zhang, Clas Collaboration

Physics Faculty Publications

The (W,Q²) dependence of the ratio of inclusive electron scattering cross sections for ¹⁵N/¹²C was determined in the kinematic ranges 0.8 < W < 2 GeV and 0.2 < Q² < 1 GeV² using 2.285 GeV electrons and the CLAS detector at Jefferson Lab. The ratios exhibit only slight resonance structure, in agreement with a simple phenomenological model and an extrapolation of deep-inelastic scattering ratios to low Q². Ratios of ⁴He/¹²C using 1.6 to 2.5 GeV electrons were measured with very high statistical precision and were used to correct for He in the N and C targets. …

Next-To-Leading Order Evolution Of Color Dipoles, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

The small-x deep inelastic scattering in the saturation region is governed by the nonlinear evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the Balitsky-Kovchegov equation for the evolution of color dipoles. In the next-to-leading order the Balitsky-Kovchegov equation gets contributions from quark and gluon loops as well as from the tree gluon diagrams with quadratic and cubic nonlinearities. We calculate the gluon contribution to the small-x evolution of Wilson lines (the quark part was obtained earlier).

Evaluation Of Nutrient (Protein) – Organism (Fish) Relationship Using A Saturation Kinetic Model, Zainab Saad Abdul Rahman

Theses

The primary objective of this thesis was to demonstrate that the net nutrient (protein) deposition and weight gain as a function of nutrient (protein) intake fits the Saturation Kinetic Model and utilize the model parameters to describe and predict intake-deposition relationship.

Groups of Nile tilapia, Oreochromis niloticus, fry (0.01 g) and small fingerlings (0.15 g) were each separately fed twelve semi purified diets in triplicates to the fingerling and duplicate to the fry trial. Each test diet contains a percentage of protein. Protein levels were 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 and 54 percent …

Biological Control Of Fusarium Oxysporum Wilt Disease Of Tomato By Antagonistic And Plant Growth Promoting Actinomycetes, Nada Mohammed Ibrahim Al-Shugairan

Theses

Soil-borne fungal plant pathogens cause some of the most widespread and serious plant diseases. Root diseases caused by these pathogens such as wilt, root rot, collar rot, foot rot, seedling pre- and post-emergence damping-off are the foremost of problems which are gaining importance from day to day in the world and for which no direct control measures have been evolved so far. Fusarium spp. is a widespread soil-borne plant pathogen and is the causal agents of wilt disease of many economically important crops. Fusarium spp. is a limiting factor in the plant productivity in most agricultural soils. Wilt disease of …

Assessment Of Marine Pollution Along Qatar’S Coasts, Mariam Saud Sadoon Al-Adba

Theses

In 2006 a study was carried out to evaluate organic and petroleum pollutants including: Total Organic Carbon (TOC), Total Petroleum Hydrocarbon (TPH), Total Kjeldahl Nitrogen (TKN), Polycyclic Aromatic Hydrocarbons (PAHs) and PolyChlorinated Biphenyls (PCBs) in coastal bottom sediments of Qatar, as well to determine the source of petroleum pollutant in the environment.

The study included 15 stations along the coastline, at a 100 m distance from the shoreline. The average TOC % analyzed in the study area is 0.262 % which is less than other regional studies. The average TPH in Qatar sediment is around 133.46 mg/kg; this is lower …