16,479 research outputs found

    Strange particle production in a single-freeze-out model

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    The transverse-momentum spectra and elliptic flow of strange particles are calculated in the framework of the single-freeze-out model and compared with the recent RHIC data. An overall very good agreement between the model predictions and the data is obtained.Comment: talk presented by WF during the VIIIth Int. Conf. on Strangeness in Quark Matter, Cape Town, Sept. 15-20, 200

    Finite Larmor radius effects on non-diffusive tracer transport in a zonal flow

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    Finite Larmor radius (FLR) effects on non-diffusive transport in a prototypical zonal flow with drift waves are studied in the context of a simplified chaotic transport model. The model consists of a superposition of drift waves of the linearized Hasegawa-Mima equation and a zonal shear flow perpendicular to the density gradient. High frequency FLR effects are incorporated by gyroaveraging the ExB velocity. Transport in the direction of the density gradient is negligible and we therefore focus on transport parallel to the zonal flows. A prescribed asymmetry produces strongly asymmetric non- Gaussian PDFs of particle displacements, with L\'evy flights in one direction but not the other. For zero Larmor radius, a transition is observed in the scaling of the second moment of particle displacements. However, FLR effects seem to eliminate this transition. The PDFs of trapping and flight events show clear evidence of algebraic scaling with decay exponents depending on the value of the Larmor radii. The shape and spatio-temporal self-similar anomalous scaling of the PDFs of particle displacements are reproduced accurately with a neutral, asymmetric effective fractional diffusion model.Comment: 14 pages, 13 figures, submitted to Physics of Plasma

    Connecting the vulcanization transition to percolation

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    The vulcanization transition is addressed via a minimal replica-field-theoretic model. The appropriate long-wave-length behavior of the two- and three-point vertex functions is considered diagrammatically, to all orders in perturbation theory, and identified with the corresponding quantities in the Houghton-Reeve-Wallace field-theoretic approach to the percolation critical phenomenon. Hence, it is shown that percolation theory correctly captures the critical phenomenology of the vulcanization transition associated with the liquid and critical states.Comment: 9 pages, 5 figure

    Energy Extraction and Particle Acceleration Around Rotating Black Hole in Horava-Lifshitz Gravity

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    Penrose process on rotational energy extraction of the black hole (BH) in the original non-projectable Ho\v{r}ava-Lifshitz gravity is studied. The strong dependence of the extracted energy from the special range of parameters of the Ho\v{r}ava-Lifshitz gravity, such as parameter ΛW\Lambda_W and specific angular momentum aa has been found. Particle acceleration near the rotating BH in Ho\v{r}ava-Lifshitz gravity has been studied. It is shown that the fundamental parameter of the Ho\v{r}ava-Lifshitz gravity can impose limitation on the the energy of the accelerating particles preventing them from the infinite value.Comment: 6 pages, 3 figures, accepted for publication in Physical Review

    Truncation effects in superdiffusive front propagation with L\'evy flights

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    A numerical and analytical study of the role of exponentially truncated L\'evy flights in the superdiffusive propagation of fronts in reaction-diffusion systems is presented. The study is based on a variation of the Fisher-Kolmogorov equation where the diffusion operator is replaced by a λ\lambda-truncated fractional derivative of order α\alpha where 1/λ1/\lambda is the characteristic truncation length scale. For λ=0\lambda=0 there is no truncation and fronts exhibit exponential acceleration and algebraic decaying tails. It is shown that for λ≠0\lambda \neq 0 this phenomenology prevails in the intermediate asymptotic regime (χt)1/α≪x≪1/λ(\chi t)^{1/\alpha} \ll x \ll 1/\lambda where χ\chi is the diffusion constant. Outside the intermediate asymptotic regime, i.e. for x>1/λx > 1/\lambda, the tail of the front exhibits the tempered decay ϕ∼e−λx/x(1+α)\phi \sim e^{-\lambda x}/x^{(1+\alpha)} , the acceleration is transient, and the front velocity, vLv_L, approaches the terminal speed v∗=(γ−λαχ)/λv_* = (\gamma - \lambda^\alpha \chi)/\lambda as t→∞t\to \infty, where it is assumed that γ>λαχ\gamma > \lambda^\alpha \chi with γ\gamma denoting the growth rate of the reaction kinetics. However, the convergence of this process is algebraic, vL∼v∗−α/(λt)v_L \sim v_* - \alpha /(\lambda t), which is very slow compared to the exponential convergence observed in the diffusive (Gaussian) case. An over-truncated regime in which the characteristic truncation length scale is shorter than the length scale of the decay of the initial condition, 1/ν1/\nu, is also identified. In this extreme regime, fronts exhibit exponential tails, ϕ∼e−νx\phi \sim e^{-\nu x}, and move at the constant velocity, v=(γ−λαχ)/νv=(\gamma - \lambda^\alpha \chi)/\nu.Comment: Accepted for publication in Phys. Rev. E (Feb. 2009

    Non-diffusive transport in plasma turbulence: a fractional diffusion approach

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    Numerical evidence of non-diffusive transport in three-dimensional, resistive pressure-gradient-driven plasma turbulence is presented. It is shown that the probability density function (pdf) of test particles' radial displacements is strongly non-Gaussian and exhibits algebraic decaying tails. To model these results we propose a macroscopic transport model for the pdf based on the use of fractional derivatives in space and time, that incorporate in a unified way space-time non-locality (non-Fickian transport), non-Gaussianity, and non-diffusive scaling. The fractional diffusion model reproduces the shape, and space-time scaling of the non-Gaussian pdf of turbulent transport calculations. The model also reproduces the observed super-diffusive scaling

    Implementing BIM Management and Process Optimization Tools in Construction Management Curriculum

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    As the construction industry rapidly continues to adopt technology and Building Information Modeling practices, we need to ensure that Construction Management curriculum prepares students for what is expected after graduation. Cal Poly’s Construction Management program currently have two Building Information Modeling courses in the curriculum that focus mainly on learning software and while this will be essential for students graduating the Construction Management program, there remains room to improve the courses as the industry adapts. Adding curriculum geared more toward managing the BIM process and learning process optimization skills will not only benefit a higher percentage of students, but will also keep the Construction Management program’s courses up to date
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