Physical Sciences and Mathematics Commons^™

Quantum Dynamics Of Vortices In Mesoscopic Magnetic Disks, Ricardo Zarzuela, Eugene M. Chudnovsky, J M. Hernandez, J Tajeda

Publications and Research

Model of quantum depinning of magnetic vortex cores from line defects in a disk geometry and under the application of an in-plane magnetic field has been developed within the framework of the Caldeira-Leggett theory. The corresponding instanton solutions are computed for several values of the magnetic field. Expressions for the crossover temperature Tc and for the depinning rate \Gamma(T) are obtained. Fitting of the theory parameters to experimental data is also presented.

Turbulent Fronts Of Quantum Detonation In Molecular Magnets, Dmitry A. Garanin

Publications and Research

Dipolar-controlled quantum deflagration going over into quantum detonation in the elongated Mn_12 Ac molecular magnet in a strong transverse field has been considered within the full 3d model. It is shown that within the dipolar window around tunneling resonances the deflagration front is non-flat. With increasing bias, dipolar instability makes the front turbulent, while its speed reaches sonic values, that is a signature of detonation.

Black Hole Formation In Fuzzy Sphere Collapse, Norihiro Izuka, Daniel N. Kabat, Roy Shubho, Debajyoti Sarkar

Publications and Research

We study the collapse of a fuzzy sphere, that is a spherical membrane built out of D0-branes, in the BFSS model. At weak coupling, as the sphere shrinks, open strings are produced. If the initial radius is large then open string production is not important and the sphere behaves classically. At intermediate initial radius the back-reaction from open string production is important but the fuzzy sphere retains its identity. At small initial radius the sphere collapses to form a black hole. The crossover between the later two regimes is smooth and occurs at the correspondence point of Horowitz and Polchinski.

On Three Dimensions As The Preferred Dimensionality Of Space Via The Brandenberger-Vafa Mechanism, Brian Greene, Daniel N. Kabat, Stefanos Marnerides

Publications and Research

In previous work it was shown that, in accord with the Brandenberger-Vafa mechanism, three is the maximum number of spatial dimensions that can grow large cosmologically from an initial thermal fluctuation. Here we complement that work by considering the possibility of successive fluctuations. Suppose an initial fluctuation causes at least one dimension to grow, and suppose successive fluctuations occur on timescales of order alpha'^{1/2}. If the string coupling is sufficiently large, we show that such fluctuations are likely to push a three-dimensional subspace to large volume where winding modes annihilate. In this setting three is the preferred number of large …

Nfl Betting Market: Using Adjusted Statistics To Test Market Efficiency And Build A Betting Model, James P. Donnelly

CMC Senior Theses

The use of statistical analysis has been prevalent in the sports gambling industry for years. More recently, we have seen the emergence of "adjusted statistics", a more sophisticated way to examine each play and each result (further explanation below). And while adjusted statistics have become commonplace for professional and recreational bettors alike, little research has been done to justify their use. In this paper the effectiveness of this data is tested on the most heavily wagered sport in the world – the National Football League (NFL). The results are studied with two central questions in mind: Does the market account …

Global And Finitistic Dimension Of Hopf-Galois Extensions, Ling Liu, Qiaoling Guo

Turkish Journal of Mathematics

Let H be a Hopf algebra over a field k and A/B a right H-Galois extension. Then in this note a spectral sequence for Ext will be constructed which yields the estimate for global dimension of A in terms of the corresponding data for H and B. As an application, we obtain the Maschke-type theorems for crossed products and twisted smash products. Finally, the relationship of finitistic dimensions between A and B will be given, if H is semisimple.

Existence And Multiplicity Of Positive Solutions For A Class Of Nonlinear Elliptic Problems, Asadollah Aghajani, Jamile Shamshiri, Frajollah Mohammadi Yaghoobi

Turkish Journal of Mathematics

We study the existence and multiplicity of nonnegative solutions for the nonlinear elliptic problem, -\Delta u+v(x)u=a(x)u^p+\lambda f(x,u) for x\in\Omega and u=0 on \partial\Omega, where \Omega is a bounded region in R^N, N>2, 1

Sasakian Finsler Manifolds, Ayşe Funda Yaliniz, Nesri̇n Çalişkan

Turkish Journal of Mathematics

In this study, almost contact Finsler structures on vector bundle are defined and the condition of normality in terms of the Nijenhuis torsion N_{\phi} of almost contact Finsler structure is obtained. It is shown that for a K-contact structure on Finsler manifold \nabla_X \xi =-\frac{1}{2} \phi X and the flag curvature for plane sections containing \xi are equal to \frac{1}{4}. By using the Sasakian Finsler structure, the curvatures of a Finsler connection \nabla on V are obtained. We prove that a locally symmetric Finsler manifold with K-contact Finsler structure has a constant curvature \frac{1}{4}. Also, the Ricci curvature on Finsler …

New Trace Formula For The Matrix Sturm-Liouville Equation With Eigenparameter Dependent Boundary Conditions, Chuan Fu Yang

Turkish Journal of Mathematics

A regularized trace formula of first order for the matrix Sturm-Liouville equation with eigenparameter in the boundary conditions is obtained.

Finite Rings And Wilson's Theorem, Yasuyuki Hirano, Manabu Matsuoka

Turkish Journal of Mathematics

In this paper we consider the product of all elements in the group of units in a finite ring and we generalize Wilson's theorem to finite rings. As an application, we study some generalizations of Wilson's theorem on residually finite Dedekind domains. And we also give some examples for such rings. Moreover we study some generalizations of Wilson's theorem on rings of matrices over a finite commutative ring.

On Theta Pair For A Proper Subalgebra, Ali Reza Salemkar, Sara Chehrazi, Hamid Mohammadzadeh

Turkish Journal of Mathematics

For a proper subalgebra K of a finite dimensional Lie algebra L, a pair (A,B) of subalgebras of L is called a \theta-pair if L = \langle A,K\rangle, B is the largest ideal of L contained in A\cap K and for each proper subalgebra C/B of A/B which is an ideal of L/B, we have L\neq C+K. In this article, using this concept, we give some characterizations of solvability and supersolvability of a finite dimensional Lie algebra.

On Integrability Of Golden Riemannian Structures, Aydin Gezer, Nejmi̇ Cengi̇z, Arif Salimov

Turkish Journal of Mathematics

The main purpose of the present paper is to study the geometry of Riemannian manifolds endowed with Golden structures. We discuss the problem of integrability for Golden Riemannian structures by using a \phi-operator which is applied to pure tensor fields. Also, the curvature properties for Golden Riemannian metrics and some properties of twin Golden Riemannian metrics are investigated. Finally, some examples are presented.

L^P Solutions Of Infinite Time Interval Bsdes And The Corresponding G-Expectations And G-Martingales, Zhaojun Zong

Turkish Journal of Mathematics

In this paper we study the existence and uniqueness theorem for L^p (1

Cross Sections Spring/Summer 2013, Department Of Physics And Astronomy

Cross Sections

No abstract provided.

Utk Geography Newsletter 13 (2012-2013), Department Of Geography

UTK Geography Newsletter

No abstract provided.

Cross Sections Fall 2012/Winter 2013, Department Of Physics And Astronomy

Cross Sections

No abstract provided.

Math Department Newsletter, 2012-2013 (Year In Review), Mathematics Department

Mathematics Newsletter

No abstract provided.

Chemical Reactivity Worksheet, Noaa, Jeffrey H. Glans

Chemistry & Physics Faculty Publications

Website overview by Jeffrey H. Glans.

NOAA. Office of Response and Restoration. "Chemical Reactivity Worksheet, NOAA." http://response.restoration.noaa.gov/crw

Safe Harbor For The Innocent Infringer In The Digital Age, Tonya M. Evans

Law Faculty Scholarship

The primary goal of this Article is three-fold: (1) to explore the role of the innocent infringer archetype historically and in the digital age; (2) to highlight the tension between customary and generally accepted online uses and copyright law that compromise efficient use of technology and progress of the digital technologies, the Internet, and society at large; and (3) to offer a legislative fix in the form of safe harbor for direct innocent infringers. Such an exemption seems not only more efficient but also more just in the online environment where unwitting infringement for the average copyright consumer is far …

Scaling Of The Coercive Field In Ferroelectrics At The Nanoscale, R. V. Gaynutdinov, M. Minnekaev, S. Mitko, A. L. Tolstikhina, A. Zenkevich, Stephen Ducharme, Vladimir M. Fridkin

Stephen Ducharme Publications

The scaling of the coercive field in ferroelectric films at the nanoscale is investigated experimentally. The scaling in the films of copolymer vinylidene fluoride and BaTiO3 with thickness equal by the order of value to the critical domain nucleus size 1–10 nm reveals deviation from the well-known Kay–Dunn law. At this thickness region coercive field does not depend on thickness and coincides with Landau–Ginzburg–Devonshire value.

Effect Of Exchange Interactions On The Coercivity Of Smco5 Nanoparticles Made By Cluster Beam Deposition, O Akdogan, W Li, B Balasubrmanian, David J. Sellmyer, George C. Hadjipanayis

David Sellmyer Publications

Single crystal SmCo₅ nanoparticles with an average size of 3.5 nm are produced by cluster-beam deposition. When deposited without matrix, the nanoparticles showed a super-paramagnetic be-havior with a blocking temperature of 145 K. Dispersion of the SmCo₅ nanoparticles in a carbon matrix results in an increase in both the coercivity and the blocking temperature. Room temperature coercivities as high as 12 kOe are obtained for the first time in mono-layers of SmCo₅ nanoparticles dispersed in C matrix. δM plots show that the interactions in the samples are of exchange type, which can decrease the overall effective …

Novel Nanostructured Rare-Earth-Free Magnetic Materials With High Energy Products, Balamurugan Balasubramanian, Bhaskar Das, Ralph Skomski, Wenyong Zhang, David J. Sellmyer

David Sellmyer Publications

The development of new iron- or cobalt-rich permanent-magnet materials is of paramount importance in materials science and technology since high-performance materials based on Nd₂Fe₁₄B or FePt are extremely expensive or subject to limited rare-earth supplies.^[1–4] Aside from phase-diagram considerations, this requires alloys with high magnetocrystal-line anisotropy K1 and Curie temperature Tc. However, the range of alternative compounds with appreciable K1 and high Tc is limited, and the situation is often aggravated by their metastable nature and by the requirement of high-formation temperatures.^[5–12] For exam-ple, two suitable candidates are Zr₂Co₁₁ and HfCo …

Solubility Extension And Phase Formation In Gas-Condensed Co–W Nanoclusters, Farhad Golkar, Matthew J. Kramer, Ames Laboratory, Ralph A. Skomski, David J. Sellmyer, Jeffrey E. Shield

David Sellmyer Publications

Co–W alloy clusters with extended solubility of W in hcp Co were produced by inert-gas condensa-tion. The structural state of the as-deposited Co–W clusters was found to be critically dependent on processing parameters such as the cooling scheme and sputtering power. For the water-cooled clus-ters, the mean size and percent crystalline were strongly dependent on sputtering power, while the percent crystalline of the liquid nitrogen-cooled clusters was not as affected by the sputtering power. At low sputtering powers, the water-cooled clusters were predominantly amorphous, but became increasingly more crystalline as the sputtering power increased. The predominant crystalline phase was hcp …

Magnetism Of Rapidly Quenched Rhombohedral Zr2Co11-Based Nanocomposites, Wenyong Zhang, Xingzhong Li, Shah R. Valloppilly, Ralph A. Skomski, Jeffrey E. Shield, David J. Sellmyer

David Sellmyer Publications

The effect of quench rate and Zr content on nanostructure and magnetic properties of melt-spun Zr_xCo_100−x (x = 16–21) is investigated. High quench rate favors the formation of rhombohedral Zr₂Co₁₁, which is the hard phase. The coercivity increases with an increase in quench rate. Zr addition in limited amounts decreases the grain size of magnetic phases, which may promote the effective ex-change coupling of soft magnetic phases. Therefore, coercivity and maximum energy product of Zr₂Co₁₁-based materials are significantly enhanced. The best magnetic properties, iHc = 3.0 kOe and (BH) …

Trichodesmium-Derived Dissolved Organic Matter Is A Source Of Nitrogen Capable Of Supporting The Growth Of Toxic Red Tide Karenia Brevis, Rachel E. Sipler, Deborah A. Bronk, Sybil P. Seitzinger, Ronald J. Lauck, Lora R. Mcguinness, Gary J. Kirkpatrick, Cynthia A. Heil, Lee J. Kerkhof, Oscar M. Schofield

VIMS Articles

Dissolved organic nitrogen (DON) produced by the nitrogen-fixer Trichodesmium sp. has the potential to serve as a nitrogen source for the red tide dinoflagellate Karenia brevis. Dissolved organic matter (DOM) from laboratory cultures of Trichodesmium sp. was isolated, concentrated and then supplied as a nutrient source to K. brevis cells collected from the Gulf of Mexico. K. brevis abundance increased immediately after Trichodesmium sp. cellular exudate (TCE) addition, allowing the population to double within the first 24 h. There was rapid and complete utilization of the TCE DON as well as ~89% of the TCE dissolved organic phosphorus (DOP). Additionally, …

Development Of Laser Spectroscopy For Elemental And Molecular Analysis, Yuan Liu

Electronic Theses and Dissertations

Laser-Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy are still growing analytical and sensing spectroscopic techniques. They significantly reduce the time and labor cost in analysis with simplified instrumentation, and lead to minimal or no sample damage. In this dissertation, fundamental studies to improve LIBS analytical performance were performed and its fusion with Raman into one single sensor was explored. On the fundamental side, Thomson scattering was reported for the first time to simultaneously measure the electron density and temperature of laser plasmas from a solid aluminum target at atmospheric pressure. Comparison between electron and excitation temperatures brought insights into the …

Using Mapreduce Streaming For Distributed Life Simulation On The Cloud, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Books and Book Chapters

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable …

Thermal Tuning Of Mid-Infrared Plasmonic Antenna Arrays Using A Phase Change Material, Mikhail A. Kats, Romain Blanchard, (...), M. M. Qazilbash, Et Al.

Arts & Sciences Articles

We demonstrate that the resonances of infrared plasmonic antennas can be tuned or switched on/off by taking advantage of the thermally driven insulator-to-metal phase transition in vanadium dioxide (VO2). Y-shaped antennas were fabricated on a 180 nm film of VO2 deposited on a sapphire substrate, and their resonances were shown to depend on the temperature of the VO2 film in proximity of its phase transition, in good agreement with full-wave simulations. We achieved tunability of the resonance wavelength of approximately 10% (>1 μm at λ ∼ 10 μm).

Nonnegativity Of Exact And Numerical Solutions Of Some Chemotactic Models, Patrick De Leenheer, Jay Gopalakrishnan, Erica Zuhr

Mathematics and Statistics Faculty Publications and Presentations

We investigate nonnegativity of exact and numerical solutions to a generalized Keller–Segel model. This model includes the so-called “minimal” Keller–Segel model, but can cover more general chemistry. We use maximum principles and invariant sets to prove that all components of the solution of the generalized model are nonnegative. We then derive numerical methods, using finite element techniques, for the generalized Keller–Segel model. Adapting the ideas in our proof of nonnegativity of exact solutions to the discrete setting, we are able to show nonnegativity of discrete solutions from the numerical methods under certain standard assumptions. One of the numerical methods is …

New Yellow Ba0.93Eu0.07Al2O4, Xufan Li, John D. Budai, Feng Liu, Jane Y. Howe, Jiahua Zhang, Xiao-Jun Wang, Zhanjun Gu, Chengjun Sun, Richard S. Meltzer, Zhengwei Pan

Department of Physics and Astronomy Faculty Publications

Phosphor-converted white light-emitting diodes for indoor illumination need to be warm-white (i.e., correlated color temperature K) with good color rendition (i.e., color rendering index >80). However, no single-phosphor, single-emitting-center-converted white light-emitting diodes can simultaneously satisfy the color temperature and rendition requirements due to the lack of sufficient red spectral component in the phosphors’ emission spectrum. Here, we report a new yellow Ba_0.93Eu_0.07Al₂O₄phosphor that has a new orthorhombic lattice structure and exhibits a broad yellow photoluminescence band with sufficient red spectral component. Warm-white emissions with correlated color temperature 80 were readily achieved when …