Quantitative Study Of Spin-Flip Co-Tunneling Transport In A Quantum Dot, 2012 Xavier University - Cincinnati

#### Quantitative Study Of Spin-Flip Co-Tunneling Transport In A Quantum Dot, S. Herbert, T-M. Liu, A. N. Ngo

*Faculty Scholarship*

No abstract provided.

Flow Over A Traveling Wavy Foil With A Passively Flapping Flat Plate, 2012 Old Dominion University

#### Flow Over A Traveling Wavy Foil With A Passively Flapping Flat Plate, Nansheng Liu, Yan Peng, Youwen Liang, Xiyun Lu

*Mathematics & Statistics Faculty Publications*

Flow over a traveling wavy foil with a passively flapping flat plate has been investigated using a multiblock lattice Boltzmann equation and the immersed boundary method. The foil undergoes prescribed undulations in the lateral direction and the rigid flat plate has passive motion determined by the fluid structure interaction. This simplified model is used to study the effect of the fish caudal fin and its flexibility on the locomotion of swimming animals. The flexibility of the caudal fin is modeled by a torsion spring acting about the pivot at the conjuncture of the wavy foil and the flat plate. The ...

Approach To Accurately Measuring The Speed Of Optical Precursors, 2011 University of Science and Technology of China

#### Approach To Accurately Measuring The Speed Of Optical Precursors, Chuan-Feng Li, Zong-Quan Zhou, Heejeong Jeong, Guang-Can Guo

*Open Dartmouth: Faculty Open Access Scholarship*

Precursors can serve as a bound on the speed of information with dispersive medium. We propose a method to identify the speed of optical wavefronts using polarization-based interference in a solid-state device, which can bound the accuracy of the speed of wavefronts to less than 10−4 with conventional experimental conditions. Our proposal may have important implications for optical communications and fast information processing.

Phase-Field Investigation Of Rod Eutectic Morphologies Under Geometrical Confinement, 2011 Iowa State University

#### Phase-Field Investigation Of Rod Eutectic Morphologies Under Geometrical Confinement, Melis Şerefoğlu, Ralph E. Napolitano, Mathis Plapp

*Materials Science and Engineering Publications*

Three-dimensional phase-field simulations are employed to investigate rod-type eutectic growth morphologies in confined geometry. Distinct steady-state solutions are found to depend on this confinement effect with the rod array basis vectors and their included angle (α) changing to accommodate the geometrical constraint. Specific morphologies are observed, including rods of circular cross sections, rods of distorted (elliptical) cross sections, rods of peanut-shaped cross-sections, and lamellar structures. The results show that, for a fixed value of α>10∘, the usual (triangular) arrays of circular rods are stable in a broad range of spacings, with a transition to the peanut-shaped cross sectioned rods ...

Exact Solutions For Social And Biological Contagion Models On Mixed Directed And Undirected, Degree-Correlated Random Networks, 2011 Dartmouth College

#### Exact Solutions For Social And Biological Contagion Models On Mixed Directed And Undirected, Degree-Correlated Random Networks, Joshua L. Payne, Kameron Decker Harris, Peter Sheridan Dodds

*Open Dartmouth: Faculty Open Access Scholarship*

We derive analytic expressions for the possibility, probability, and expected size of global spread- ing events starting from a single infected seed for a broad collection of contagion processes acting on random networks with both directed and undirected edges and arbitrary degree-degree correla- tions. Our work extends previous theoretical developments for the undirected case, and we provide numerical support for our findings by investigating an example class of networks for which we are able to obtain closed-form expressions.

Turbulence And Bias-Induced Flows In Simple Magnetized Toroidal Plasmas, 2011 Dartmouth College

#### Turbulence And Bias-Induced Flows In Simple Magnetized Toroidal Plasmas, B. Li, B. N. Rogers, P. Ricci, K. W. Gentle

*Open Dartmouth: Faculty Open Access Scholarship*

Turbulence and bias-induced flows in simple magnetized toroidal plasmas are explored with global three- dimensional fluid simulations, focusing on the parameters of the Helimak experiment. The simulations show that plasma turbulence and transport in the regime of interest are dominated by the ideal interchange instability. The application of a bias voltage alters the structure of the plasma potential, resulting in the equilibrium sheared flows. These bias-induced vertical flows located in the gradient region appear to reduce the radial extent of turbulent structures, and thereby lower the radial plasma transport on the low field side.

Direct, Physically-Motivated Derivation Of The Contagion Condition For Spreading Processes On Generalized Random Networks, 2011 The University of Vermont

#### Direct, Physically-Motivated Derivation Of The Contagion Condition For Spreading Processes On Generalized Random Networks, Peter Sheridan Dodds, Kameron Decker Harris, Joshua L. Payne

*Open Dartmouth: Faculty Open Access Scholarship*

For a broad range of single-seed contagion processes acting on generalized random networks, we derive a unifying analytic expression for the possibility of global spreading events in a straightforward, physically intuitive fashion. Our reasoning lays bare a direct mechanical understanding of an archetypal spreading phenomena that is not evident in circuitous extant mathematical approaches.

Systematic Approach To Electrostatically Induced 2d Crystallization Of Nanoparticles At Liquid Interfaces, 2011 University of South Carolina - Columbia

#### Systematic Approach To Electrostatically Induced 2d Crystallization Of Nanoparticles At Liquid Interfaces, S. Kewalramani, S. Wang, Y. Lin, H. G. Nguyen, Qian Wang, M. Fukuto, L. Yang

*Faculty Publications*

We report an experimental demonstration of a strategy for inducing two-dimensional (2D)crystallization of charged nanoparticles on oppositely charged fluid interfaces. This strategy aims to maximize the interfacial adsorption of nanoparticles, and hence their lateral packing density, by utilizing a combination of weakly charged particles and a high surface charge density on the planar interface. In order to test this approach, we investigated the assembly of cowpea mosaic virus (CPMV) on positively charged lipid monolayers at the aqueous solution surface, by means of *in situ*X-ray scattering measurements at the liquid–vapor interface. Theassembly was studied as a function of ...

Boundary Conditions For Burton–Cabrera–Frank Type Step-Flow Models: Coarse-Graining Of Discrete 2d Deposition-Diffusion Equations, 2011 Iowa State University

#### Boundary Conditions For Burton–Cabrera–Frank Type Step-Flow Models: Coarse-Graining Of Discrete 2d Deposition-Diffusion Equations, David M. Ackerman, James W. Evans

*Physics and Astronomy Publications*

We analyze discrete two-dimensional (2D) deposition-diffusion equations for the density of adatoms deposited at a periodic array of adsorption sites on a vicinal crystalline surface with kinked steps. Our analysis provides insight into the appropriate boundary conditions (BC) at steps for a coarse-grained Burton-Cabrera-Frank (BCF) type treatment involving continuum 2D deposition-diffusion equations. Such a BCF type treatment should describe step flow on vicinal surfaces under nonequilibrium growth conditions. We focus on cases where there is no additional activation barrier inhibiting to attachment at steps beyond that for terrace diffusion. Then, the classical BCF treatment simply imposes a Dirichlet BC equating ...

Poincare Recurrence And Spectral Cascades In Three-Dimensional Quantum Turbulence, 2011 Old Dominion University

#### Poincare Recurrence And Spectral Cascades In Three-Dimensional Quantum Turbulence, George Vahala, Jeffrey Yepez, Linda L. Vahala, Min Soe, Bo Zhang, Sean Ziegeler

*Electrical & Computer Engineering Faculty Publications*

The time evolution of the ground state wave function of a zero-temperature Bose-Einstein condensate (BEC) gas is well described by the Hamiltonian Gross-Pitaevskii (GP) equation. Using a set of appropriately interleaved unitary collision-stream operators, a qubit lattice gas algorithm is devised, which on taking moments, recovers the Gross-Pitaevskii (GP) equation under diffusion ordering (time scales as length^{2}). Unexpectedly, there is a class of initial states whose Poincaré recurrence time is extremely short and which, as the grid resolution is increased, scales with diffusion ordering (and not as length^{3}). The spectral results of J. Yepez *et al.* [Phys. Rev ...

Numerics Of The Lattice Boltzmann Method: Effects Of Collision Models On The Lattice Boltzmann Simulations, 2011 Old Dominion University

#### Numerics Of The Lattice Boltzmann Method: Effects Of Collision Models On The Lattice Boltzmann Simulations, Li-Shi Luo, Wei Liao, Xingwang Chen, Yan Peng, Wei Zhang

*Mathematics & Statistics Faculty Publications*

We conduct a comparative study to evaluate several lattice Boltzmann (LB) models for solving the near incompressible Navier-Stokes equations, including the lattice Boltzmann equation with the multiple-relaxation-time (MRT), the two-relaxation-time (TRT), the single-relaxation-time (SRT) collision models, and the entropic lattice Boltzmann equation (ELBE). The lid-driven square cavity flow in two dimensions is used as a benchmark test. Our results demonstrate that the ELBE does not improve the numerical stability of the SRT or the lattice Bhatnagar-Gross-Krook (LBGK) model. Our results also show that the MRT and TRT LB models are superior to the ELBE and LBGK models in terms of ...

On The Thresholds In Linear And Nonlinear Boolean Equations, 2010 Renmin University of China

#### On The Thresholds In Linear And Nonlinear Boolean Equations, Yifan Sun Dr

*Yifan Sun*

No abstract provided.

Algebraic Characteristics And Satisfiability Threshold Of Random Boolean Equations, 2010 Beihang University

#### Algebraic Characteristics And Satisfiability Threshold Of Random Boolean Equations, Binghui Guo Dr, Wei Wei Dr, Yifan Sun Dr, Zhiming Zheng Dr

*Yifan Sun*

No abstract provided.

The Effect Of Node-Degree Correlation On Synchronization Of Identical Pulse-Coupled Oscillators, 2010 College of William and Mary

#### The Effect Of Node-Degree Correlation On Synchronization Of Identical Pulse-Coupled Oscillators, M Drew Lamar, Gregory D. Smith

*Applied Science Articles & Book Chapters*

We explore the effect of correlations between the in and out degrees of random directed networks on the synchronization of identical pulse-coupled oscillators. Numerical experiments demonstrate that the proportion of initial conditions resulting in a globally synchronous state (prior to a large but finite time) is an increasing function of node-degree correlation. For those networks observed to globally synchronize, both the mean and standard deviation of time to synchronization are decreasing functions of node-degree correlation. Pulse-coupled oscillator networks with negatively correlated node degree often exhibit multiple coherent attracting states, with trajectories performing fast transitions between them. These effects of node-degree ...

Effects Of Multitemperature Nonequilibrium On Compressible Homogeneous Turbulence, 2010 Old Dominion University

#### Effects Of Multitemperature Nonequilibrium On Compressible Homogeneous Turbulence, Wei Liao, Yan Peng, Li-Shi Luo

*Mathematics & Statistics Faculty Publications*

We study the effects of the rotational-translational energy exchange on the compressible decaying homogeneous isotropic turbulence (DHIT) in three dimensions through direct numerical simulations. We use the gas-kinetic scheme coupled with multitemperature nonequilibrium based on the Jeans-Landau-Teller model. We investigate the effects of the relaxation time of rotational temperature, *Z _{R}*, and the initial ratio of the rotational and translational temperatures,

*T*/

_{R0}*T*on the dynamics of various turbulence statistics including the kinetic energy K (t), the dissipation rate ε (t), the energy spectrum E (k,t), the root mean square of the velocity divergence θ′ (t), the ...

_{L0},