Search results for "NUMB"

showing 6 items of 3956 documents

Structure and dynamics in liquid bismuth and Bin clusters: A density functional study

2014

Density functional/molecular dynamics simulations with more than 500 atoms have been performed on liquid bismuth at 573, 773, 923, and 1023 K and on neutral Bi clusters with up to 14 atoms. There are similar structural patterns (coordination numbers, bond angles, and ring patterns) in the liquid and the clusters, with significant differences from the rhombohedral crystalline form. We study the details of the structure (structure factor, pair, and cavity distribution functions) and dynamical properties (vibration frequencies, diffusion constants, power spectra), and compare with experimental results where available. While the three short covalent bonds typical to pnictogens are characteristi…

vibration frequencyCoordination numberGeneral Physics and Astronomychemistry.chemical_element02 engineering and technology01 natural sciencesMolecular physicsBinBismuthMolecular dynamics0103 physical sciencesAtomPhysical and Theoretical Chemistry010306 general physicsconcentration variationspin-orbit couplingsta114021001 nanoscience & nanotechnologybismuth distribution functionsdynamical propertiesMolecular geometrychemistrydensity functionalsddc:540structure and dynamicsDensity functional theoryAtomic physics0210 nano-technologyStructure factordensity-functional studycoordination numberJournal of chemical physics
researchProduct

High-Reynolds-number turbulent cavity flow using the lattice Boltzmann method

2018

We present a boundary condition scheme for the lattice Boltzmann method that has significantly improved stability for modeling turbulent flows while maintaining excellent parallel scalability. Simulations of a three-dimensional lid-driven cavity flow are found to be stable up to the unprecedented Reynolds number $\mathrm{Re}=5\ifmmode\times\else\texttimes\fi{}{10}^{4}$ for this setup. Excellent agreement with energy balance equations, computational and experimental results are shown. We quantify rises in the production of turbulence and turbulent drag, and determine peak locations of turbulent production.

virtauslaskentaLattice Boltzmann methodsEnergy balance01 natural sciencesStability (probability)010305 fluids & plasmasPhysics::Fluid Dynamicssymbols.namesaketurbulenssi0103 physical sciencesBoundary value problem010306 general physicsPhysicsta114numeeriset menetelmätTurbulenceBoltzmann methodReynolds numberMechanicscavity flowSettore FIS/02 - Fisica Teorica Modelli e Metodi MatematiciDragsymbolsProduction (computer science)Computational fluid dynamics; Lattice Boltzmann Methods; Turbulent cavity flowsdifferentiaaliyhtälöt
researchProduct

Kinetics of phase separation in thin films: Lattice versus continuum models for solid binary mixtures

2008

A description of phase separation kinetics for solid binary (A,B) mixtures in thin film geometry based on the Kawasaki spin-exchange kinetic Ising model is presented in a discrete lattice molecular field formulation. It is shown that the model describes the interplay of wetting layer formation and lateral phase separation, which leads to a characteristic domain size $\ell(t)$ in the directions parallel to the confining walls that grows according to the Lifshitz-Slyozov $t^{1/3}$ law with time $t$ after the quench. Near the critical point of the model, the description is shown to be equivalent to the standard treatments based on Ginzburg-Landau models. Unlike the latter, the present treatmen…

wettingMaterials scienceStatistical Mechanics (cond-mat.stat-mech)Condensed matter physicscritical pointsGinzburg-Landau theoryTime evolutionFOS: Physical sciencesBinary numberfree energyLattice constantthin filmsCritical point (thermodynamics)Lattice (order)Ising modelWettingphase separationThin filmCondensed Matter - Statistical MechanicsWetting layerPhysical Review E
researchProduct

Deformation Quantization in White Noise Analysis

2007

We define and present an example of a deformation quantization product on a Hida space of test functions endowed with a Wick product.

white noise analysisMoyal productQuantization (signal processing)lcsh:MathematicsMathematics::Number TheoryMathematical analysisFOS: Physical sciencesWhite noiseMathematical Physics (math-ph)lcsh:QA1-939Mathematics - Quantum AlgebraFOS: MathematicsMoyal productQuantum Algebra (math.QA)Geometry and TopologyWick productAnalysisMathematical PhysicsMathematicsMathematical physics
researchProduct

First and second order rational solutions to the Johnson equation and rogue waves

2018

Rational solutions to the Johnson equation are constructed as a quotient of two polynomials in x, y and t depending on several real parameters. We obtain an infinite hierarchy of rational solutions written in terms of polynomials of degrees 2N (N + 1) in x, and t, 4N (N + 1) in y, depending on 2N − 2 real parameters for each positive integer N. We construct explicit expressions of the solutions in the cases N = 1 and N = 2 which are given in the following. We study the evolution of the solutions by constructing the patterns of their modulus in the (x, y) plane, and this for different values of parameters.

wronskiansJohnson equation4710A-[ MATH.MATH-MP ] Mathematics [math]/Mathematical Physics [math-ph]ratio-rogue wavesnal solutions37K10[MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph][MATH.MATH-MP] Mathematics [math]/Mathematical Physics [math-ph]33Q554735FgPACS numbers :4754BdFredholm determinants
researchProduct

Sustainable Physical Activity Programs for Young Elderly : A Fuzzy Analytic Hierarchy Process Approach

2020

Physical activity (PA) programs are useful to help young elderly stay in good shape for their senior years. These programs should be sustainable, as this would keep the users active for months and years. A PA program should build on activities that users find meaningful and/or best suited for their history of sports and exercise as well as their present physical capacity. The challenge is to make the best selection from a (long) list of possible activities. We worked out a method to help young elderly to build a sustainable PA program from a set of activities that experts have identified as contributing to health and fitness among young elderly. The method builds on the Analytical Hierarchy…

young elderlysustainable physical activity programshyvinvointiteknologiamittauslaitteetnuoret ikääntyneetfuzzy numbersfuzzy AHPliikuntaanalytic hierarchy processikääntyneetfyysinen aktiivisuusohjattu liikunta
researchProduct