The vector channel spectral function at zero spatial momentum is calculated at next-to-leading order in thermal QCD for any quark mass. It corresponds to the imaginary part of the massive quark contribution to the photon polarization tensor. The spec
trum shows a well defined transport peak in contrast to both the heavy quark limit studied previously, where the low frequency domain is exponentially suppressed at this order and the naive massless case where it vanishes at leading order and diverges at next-to-leading order. From our general expressions, the massless limit can be taken and we show that no divergences occur if done carefully. Finally, we compare the massless limit to results from lattice simulations.
Guided by extensive numerical simulations, we propose a microfluidic device that can sort elastic capsules by their deformability. The device consists of a duct embedded with a semi-cylindrical obstacle, and a diffuser which further enhances the sort
ing capability. We demonstrate that the device can operate reasonably well under changes in the initial position of the the capsule. The efficiency of the device remains essentially unaltered under small changes of the obstacle shape (from semi-circular to semi-elliptic cross-section). Confinement along the direction perpendicular to the plane of the device increases its efficiency. This work is the first numerical study of cell sorting by a realistic microfluidic device.
In countries with a moderate seismic hazard, the classical methods developed for strong motion prone countries to estimate the seismic behaviour and subsequent vulnerability of existing buildings are often inadequate and not financially realistic. Th
e main goals of this paper are to show how the modal analysis can contribute to the understanding of the seismic building response and the good relevancy of a modal model based on ambient vibrations for estimating the structural deformation under moderate earthquakes. We describe the application of an enhanced modal analysis technique (Frequency Domain Decomposition) to process ambient vibration recordings taken at the Grenoble City Hall building (France). The frequencies of ambient vibrations are compared with those of weak earthquakes recorded by the French permanent accelerometric network (RAP) that was installed to monitor the building. The frequency variations of the building under moderate earthquakes are shown to be slight (~2%) and therefore ambient vibration frequencies are relevant over the elastic domain of the building. The modal parameters extracted from ambient vibrations are then used to determine the 1D lumped-mass model in order to reproduce the inter-storey drift under weak earthquakes and to fix a 3D numerical model that could be used for strong earthquakes. The correlation coefficients between data and synthetic motion are close to 80% and 90% in horizontal directions, for the 1D and 3D modelling, respectively.
Seismic vulnerability analysis of existing buildings requires basic information on their structural behaviour. The ambient vibrations of buildings and the modal parameters (frequencies, damping ration and modal shapes) that can be extracted from them
naturally include the geometry and quality of material in the linear elastic part of their behaviour. The aim of this work is to use this modal information to help the vulnerability assessment. A linear dynamic modal model based on experimental modal parameters is proposed and the fragility curve corresponding to the damage state ?Slight? is built using this model and a simple formula is proposed. This curve is particularly interesting in moderate seismic areas. This methodology is applied to the Grenoble City where ambient vibrations have been recorded in 61 buildings of various types and to the Pointe-`a-Pitre City with 7 study-buildings. The fragility curves are developed using the aforementioned methodology. The seismic risk of the study-buildings is discussed by performing seismic scenarios.
We extend the strong macroscopic stability introduced in Bramson & Mountford (2002) for one-dimensional asymmetric exclusion processes with finite range to a large class of one-dimensional conservative attractive models (including misanthrope process
) for which we relax the requirement of finite range kernels. A key motivation is extension of constructive hydrodynamics result of Bahadoran et al. (2002, 2006, 2008) to nonfinite range kernels.
We present the first study of large-scale bars in clusters at intermediate redshifts (z=0.4-0.8). We compare the properties of the bars and their host galaxies in the clusters with those of a field sample in the same redshift range. We use a sample o
f 945 moderately inclined disk galaxies drawn from the EDisCS project. The morphological classification of the galaxies and the detection of bars are based on deep HST/ACS F814W images. The total optical bar fraction in the redshift range z=0.4-0.8, averaged over the entire sample, is 25%. This is lower than found locally, but in good agreement with studies of bars in field environments at intermediate redshifts. For the cluster and field subsamples, we measure bar fractions of 24% and 29%, respectively. In agreement with local studies, we find that disk-dominated galaxies have a higher bar fraction than bulge-dominated galaxies. We also find, based on a small subsample, that bars in clusters are on average longer than in the field and preferentially found close to the cluster center, where the bar fraction is somewhat higher than at larger distances.
We report recent measurements of the Unitarity triangle angles phi_1 and phi_2 using large data samples collected with Belle and BaBar detectors at e+e- asymmetric-energy colliders.
Structural decomposition of galaxies into bulge, disk, and bar components is important to address a number of scientific problems. Measuring bulge, disk, and bar structural parameters will set constraints on the violent and secular processes of galax
y assembly and recurrent bar formation and dissolution models. It can also help to quantify the fraction and properties of bulgeless galaxies (those systems having no bulge or only a relatively insignificant disky-pseudobulges), which defy galaxy formation paradigms requiring almost every disk galaxy to have a classical bulge at its core. We demonstrate a proof of concept and show early results of our ongoing three-component bulge-disk-bar decomposition of NIR images for a sample of three complementary samples spanning different epochs and different environments (field and cluster). In contrast to most early studies, which only attempt two-component bulge-disk decomposition, we fit three components using GALFIT: a bulge, a disk, and a bar. We show that it is important to include the bar component, as this can significantly lower the bulge-to-total luminosity ratio (B/T), in many cases by a factor of two or more, thus effectively changing the Hubble type of a galaxy from early to late.
