1,478 research outputs found

    The effects of machining process variables and tooling characterisation on the surface generation: modelling, simulation and application promise

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    The paper presents a novel approach for modelling and simulation of the surface generation in the machining process. The approach, by integrating dynamic cutting force model, regenerative vibration model, machining system response model and tool profile model, models the complex surface generation process. Matlab Simulink is used to interactively perform the simulation in a user-friendly, effective and efficient manner. The effects of machining variables and tooling characteristics on the surface generation are investigated through simulations. CNC turning trials have been carried out to evaluate and validate the approach and simulations presented. The proposed approach contributes to comprehensive and better understanding of the machining system, and is promising for industrial applications with particular reference to the optimisation of the machining process based on the product/component surface functionality requirements

    Waste on the roadside, 'poi-sute' waste: Its distribution and elution potential of pollutants into environment

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    ArticleWASTE MANAGEMENT. 29(3):1192-1197 (2009)journal articl

    Cross-correlation between the 21-cm signal and [OIII] emitters during early cosmic reionization

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    We study statistics of the 21-cm signal from the epoch of reionization. We propose to use [OIII] line emitting galaxies to cross-correlate with the 21-cm signal from z=7−10z = 7 - 10. To this aim, we employ simulations of reionization obtained post-processing the high-resolution cosmological hydrodynamic simulation Massive Black-II with the three-dimensional (3D) radiative transfer code CRASH to follow the propagation of ionizing photons from a variety of sources. We show that, during the early phases of reionization, the 21-cm signal is positively correlated with the spatial distribution of the [OIII] emitters on large scales (k<1h cMpc−1)(k < 1h~\rm cMpc^{-1}). This positive correlation is generated by the temperature-galaxy correlation and it is a few times larger than when we assume that the heating is saturated. As the reionized regions expand, the correlation changes its sign to negative from z=10z = 10 to 8. The signals at this epoch can be detected by combining the Square Kilometre Array (SKA) and a wide-field [OIII] emitter survey. We also calculate the cross-power spectrum with a 3D [OIII] intensity field, aiming at exploiting future intensity mapping observations. We conclude that high-redshift [OIII] line emitters can be used to probe the reionization process when the intergalactic medium is largely neutral.Comment: 7 pages, 5 figures, published in MNRA

    Geometric Bogomolov conjecture for abelian varieties and some results for those with some degeneration (with an appendix by Walter Gubler: The minimal dimension of a canonical measure)

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    In this paper, we formulate the geometric Bogomolov conjecture for abelian varieties, and give some partial answers to it. In fact, we insist in a main theorem that under some degeneracy condition, a closed subvariety of an abelian variety does not have a dense subset of small points if it is a non-special subvariety. The key of the proof is the study of the minimal dimension of the components of a canonical measure on the tropicalization of the closed subvariety. Then we can apply the tropical version of equidistribution theory due to Gubler. This article includes an appendix by Walter Gubler. He shows that the minimal dimension of the components of a canonical measure is equal to the dimension of the abelian part of the subvariety. We can apply this result to make a further contribution to the geometric Bogomolov conjecture.Comment: 30 page

    Stability conditions and positivity of invariants of fibrations

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    We study three methods that prove the positivity of a natural numerical invariant associated to 1−1-parameter families of polarized varieties. All these methods involve different stability conditions. In dimension 2 we prove that there is a natural connection between them, related to a yet another stability condition, the linear stability. Finally we make some speculations and prove new results in higher dimension.Comment: Final version, to appear in the Springer volume dedicated to Klaus Hulek on the occasion of his 60-th birthda
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