Search results for "Lattic"

Designing a graphics processing unit accelerated petaflop capable lattice Boltzmann solver: Read aligned data layouts and asynchronous communication

2017

The lattice Boltzmann method is a well-established numerical approach for complex fluid flow simulations. Recently, general-purpose graphics processing units (GPUs) have become available as high-performance computing resources at large scale. We report on designing and implementing a lattice Boltzmann solver for multi-GPU systems that achieves 1.79 PFLOPS performance on 16,384 GPUs. To achieve this performance, we introduce a GPU compatible version of the so-called bundle data layout and eliminate the halo sites in order to improve data access alignment. Furthermore, we make use of the possibility to overlap data transfer between the host central processing unit and the device GPU with comp…

The charm-quark contribution to light-by-light scattering in the muon (−2) from lattice QCD

2022

We compute the hadronic light-by-light scattering contribution to the muon $g-2$ from the charm quark using lattice QCD. The calculation is performed on ensembles generated with dynamical $(u,d,s)$ quarks at the SU(3)$_{\rm f}$ symmetric point with degenerate pion and kaon masses of around 415 MeV. It includes the connected charm contribution, as well as the leading disconnected Wick contraction, involving the correlation between a charm and a light-quark loop. Cutoff effects turn out to be sizeable, which leads us to use lighter-than-physical charm masses, to employ a broad range of lattice spacings reaching down to 0.039 fm and to perform a combined charm-mass and continuum extrapolation.…

Evaluation of a lattice-Boltzmann method for mercury intrusion porosimetry simulations

2004

We have simulated intrusion of a non-wetting liquid into pores of varying shape and size. Simulations were based on the lattice-Boltzmann method and the Shan–Chen multiphase model. The liquid–solid contact angle for pores with circular cross-section was found to be equal to that for pores with square cross-section, and constant even for small pore sizes if the discretised shape of the circular cross-section was taken into account. For comparison, contact angle was also determined for a liquid column descending in a capillary tube, and the results were found to be consistent. Application of the method to mercury intrusion porosimetry is discussed.

La biodiversità microbica in relazione ad alcune produzioni della regione Umbria: formaggio pecorino e mozzarella fior di latte

2006

Perception of odour mixtures: the next challenge in flavour analysis.

2017

Short paper dans conférence.; International audience; The olfactory dimension of food flavour is critical to the food identity and typicality. Food odour and aroma result from the processing of complex mixtures of volatile compounds activating the sense of smell. The perceptual properties of odour mixtures have been explored from both the aroma analysis point of view and the psychophysical point of view, thus revealing perceptual effects such as masking, synergy, or perceptual blending. However, considering odorants separately, the classical aroma analysis approach misses the central role of perceptual integration in odour mixture processing. Therefore, the challenge of food flavour analysi…

Noise effect in a sine-Gordon Lattice

2013

International audience; This paper is devoted to the influence of internal noise in a sine-Gordon chain exhibiting the well known nonlinear supratransmission phenomenon. It is shown that spatiotemporal noise can trigger breather modes with a given probability in a range of parameters where they do not occur without noise. A frequency analysis is carried out to quantify the degree of coherence of the emitted breather. It is shown that there exists an appropriate amount of noise which ensures the existence of breather modes with the best coherence.

Spatial Solitons in 2D Lattices of a Nonlinear Nature

2008

These authors describe their observation of two-color optical solitons in a 2D parametric photonic lattice with hexagonal symmetry in lithium niobate. Their results have enabled wavelength-controlled angular steering and the displacement of self-trapped filaments of light.

The strong coupling constant: State of the art and the decade ahead

2022

This document provides a comprehensive summary of the state-of-the-art, challenges, and prospects in the experimental and theoretical study of the strong coupling $\alpha_s$. The current status of the seven methods presently used to determine $\alpha_s$ based on: (i) lattice QCD, (ii) hadronic $\tau$ decays, (iii) deep-inelastic scattering and parton distribution functions fits, (iv) electroweak boson decays, hadronic final-states in (v) e+e-, (vi) e-p, and (vii) p-p collisions, and (viii) quarkonia decays and masses, are reviewed. Novel $\alpha_s$ determinations are discussed, as well as the averaging method used to obtain the PDG world-average value at the reference Z boson mass scale, $\…

Interactions of membranes with coarse-grain proteins: a comparison

2012

We study the interactions between lipid bilayers and rigid transmembrane proteins by Monte Carlo simulations of generic coarse-grain models. Different popular protein models are considered and compared with each other, and key parameters such as the hydrophobicity and the hydrophobic mismatch are varied systematically. Furthermore, the properties of the membrane are manipulated by applying different tensions. The response of the membrane to the insertion of single proteins is found to be mostly generic and independent of the choice of the protein model. Likewise, the orientational distributions of single proteins depend mainly on the hydrophobic mismatch and the hydrophobicity of the protei…

"Table 1" of "Combination of the searches for pair-produced vector-like partners of the third-generation quarks at $\sqrt{s} =$ 13 TeV with the ATLAS…

2018

Expected and observed 95% lower limits on the vector-like top quark mass as a function of the branching ratio, asumming that the vector-like quarks exclusively decay to SM particles (and third generation quarks).