5,300 research outputs found

    Critical behaviour of SU(2) lattice gauge theory. A complete analysis with the χ2\chi^2-method

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    We determine the critical point and the ratios β/ν\beta/\nu and γ/ν\gamma/\nu of critical exponents of the deconfinement transition in SU(2)SU(2) gauge theory by applying the χ2\chi^2-method to Monte Carlo data of the modulus and the square of the Polyakov loop. With the same technique we find from the Binder cumulant grg_r its universal value at the critical point in the thermodynamical limit to −1.403(16)-1.403(16) and for the next-to-leading exponent ω=1±0.1\omega=1\pm0.1. From the derivatives of the Polyakov loop dependent quantities we estimate then 1/ν1/\nu. The result from the derivative of grg_r is 1/ν=0.63±0.011/\nu=0.63\pm0.01, in complete agreement with that of the 3d3d Ising model.Comment: 11 pages, 3 Postscript figures, uses Plain Te

    Branched chain aldehydes: production and breakdown pathways and relevance for flavour in foods

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    Branched aldehydes, such as 2-methyl propanal and 2- and 3-methyl butanal, are important flavour compounds in many food products, both fermented and non-fermented (heat-treated) products. The production and degradation of these aldehydes from amino acids is described and reviewed extensively in literature. This paper reviews aspects influencing the formation of these aldehydes at the level of metabolic conversions, microbial and food composition. Special emphasis was on 3-methyl butanal and its presence in various food products. Knowledge gained about the generation pathways of these flavour compounds is essential for being able to control the formation of desired levels of these aldehydes

    Non-perturbative determination of anisotropy coefficients in lattice gauge theories

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    We propose a new non-perturbative method to compute derivatives of gauge coupling constants with respect to anisotropic lattice spacings (anisotropy coefficients), which are required in an evaluation of thermodynamic quantities from numerical simulations on the lattice. Our method is based on a precise measurement of the finite temperature deconfining transition curve in the lattice coupling parameter space extended to anisotropic lattices by applying the spectral density method. We test the method for the cases of SU(2) and SU(3) gauge theories at the deconfining transition point on lattices with the lattice size in the time direction Nt=4N_t=4 -- 6. In both cases, there is a clear discrepancy between our results and perturbative values. A longstanding problem, when one uses the perturbative anisotropy coefficients, is a non-vanishing pressure gap at the deconfining transition point in the SU(3) gauge theory. Using our non-perturbative anisotropy coefficients, we find that this problem is completely resolved: we obtain Δp/T4=0.001(15)\Delta p/T^4 = 0.001(15) and −0.003(17)-0.003(17) on Nt=4N_t=4 and 6 lattices, respectively.Comment: 24pages,7figures,5table

    Structural dynamics payload loads estimates: User guide

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    This User Guide with an overview of an integration scheme to determine the response of a launch vehicle with multiple payloads. Chapter II discusses the software package associated with the integration scheme together with several sample problems. A short cut version of the integration technique is also discussed. The Guide concludes with a list of references and the listings of the subroutines

    Moving along the non-motor spectrum of Parkinson's disease

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    Scherder, E.J.A. [Promotor]Weinstein, H. [Promotor]Douw, L. [Copromotor]Vlaar, A.M.M. [Copromotor

    Principles and effects of microRNA-mediated post-transcriptional gene regulation

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    MicroRNAs (miRNAs) are abundant regulatory RNAs involved in the regulation of many key biological processes. Recent advances in understanding the mechanism of RNA interference and miRNA-mediated mechanisms shed light on major principals of the formation of the regulatory complex and provide models to explain how these small regulatory RNA species interfere with gene expression and how they influence the translational status of the transcriptome. © 2006 Nature Publishing Group. All rights reserved

    To what extent do the Classical Equations of Motion Determine the Quantization Scheme?

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    A simple example of one particle moving in a (1+1) space-time is considered. As an example we take the harmonic oscillator. We confirm the statement that the classical Equations of Motion do not determine at all the quantization scheme. To this aim we use two inequivalent Lagrange functions, yielding Euler-Lagrange Equations, having the same set of solutions. We present in detail the calculations of both cases to emphasize the differences occuring between them.Comment: LaTeX 20 page

    Critical behaviour and scaling functions of the three-dimensional O(6) model

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    We numerically investigate the three-dimensional O(6) model on 12^3 to 120^3 lattices within the critical region at zero magnetic field, as well as at finite magnetic field on the critical isotherm and for several fixed couplings in the broken and the symmetric phase. We obtain from the Binder cumulant at vanishing magnetic field the critical coupling J_c=1.42865(3). The universal value of the Binder cumulant at this point is g_r(J_c)=-1.94456(10). At the critical coupling, the critical exponents \gamma=1.604(6), \beta=0.425(2) and \nu=0.818(5) are determined from a finite-size-scaling analysis. Furthermore, we verify predicted effects induced by massless Goldstone modes in the broken phase. The results are well described by the perturbative form of the model's equation of state. Our O(6)-result is compared to the corresponding Ising, O(2) and O(4) scaling functions. Finally, we study the finite-size-scaling behaviour of the magnetisation on the pseudocritical line.Comment: 13 pages, 20 figures, REVTEX, fixed an error in the determination of R_\chi and changed the corresponding line in figure 13

    Disappearance of the Abrikosov vortex above the deconfining phase transition in SU(2) lattice gauge theory

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    We calculate the solenoidal magnetic monopole current and electric flux distributions at finite temperature in the presence of a static quark antiquark pair. The simulation was performed using SU(2) lattice gauge theory in the maximal Abelian gauge. We find that the monopole current and electric flux distributions are quite different below and above the finite temperature deconfining phase transition point and agree with predictions of the Ginzburg-Landau effective theory.Comment: 12 pages, Revtex Latex, 6 figures - ps files will be sent upon reques
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