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[en] This article propose a model of universe described by Friedmann-Lemaitre with positive curvature, where the repartition of Q.S.O. shows a singular zone, occupaying an equator of the spatial hypersphere. The possibility of a contact zone between matter and antimatter is also studied. Interpreted in this model the observations of Q.S.O. show a stratification parallel to equator. This universal anisotropy seems to be perceptible in the galactic repartition
[fr]L'article propose un modele d'univers de Friedmann-Lemaitre, a courbure positive, ou la repartition des Q.S.O. fait apparaitre une zone singuliere, occupant un equateur de l'hypersphere spatiale. Nous etudions la possibilite qu'il s'agisse d'une zone de contact matiere-antimatiere. Interpretees dans ce modele, les observations des Q.S.O. font apparaitre une stratification parallele a l'equateur. Cette anisotropie universelle semble perceptible jusque dans la repartition des galaxies
[en] Highlights: • The -canalizing functions generalize both canalizing and nested canalizing functions. • Every Boolean function has a unique extended monomial form and core polynomial. • We enumerate the -variable Boolean functions with canalizing depth . Boolean network models have gained popularity in computational systems biology over the last dozen years. Many of these networks use canalizing Boolean functions, which has led to increased interest in the study of these functions. The canalizing depth of a function describes how many canalizing variables can be recursively “picked off”, until a non-canalizing function remains. In this paper, we show how every Boolean function has a unique algebraic form involving extended monomial layers and a well-defined core polynomial. This generalizes recent work on the algebraic structure of nested canalizing functions, and it yields a stratification of all Boolean functions by their canalizing depth. As a result, we obtain closed formulas for the number of -variable Boolean functions with depth , which simultaneously generalizes enumeration formulas for canalizing, and nested canalizing functions.
[en] Effective spectroscopic diagnostics rely on the ability to convert a particular flux measurement into a physical interpretation. Knowledge of uncertainty is a central component of diagnostics. We present data from a simulated solar-like chromosphere, where we have addressed the question of whether degeneracy is a problem in mapping from a non-LTE chromospheric line profile to a particular vertical stratification of atmospheric properties along the line of sight. Our results indicate that stratification degeneracies do exist, at least in our simulated atmosphere. We quantify this effect through the creation of posterior densities for atmospheric properties based on the Mg ii h line profile using the approximate Bayesian computation (ABC) technique. We find that the predictive power of the ABC temperature posterior systematically varies as a function of atmospheric column mass and ground-truth temperature. The ABC posteriors more effectively reproduce the spectral intensity in the Ca ii 8542 Å line than they do temperature stratification, although residual error in the Ca ii line core is common. Our results illustrate that some degeneracies should be alleviated through simultaneous analysis of multiple chromospheric lines.
[en] Gravitational settling of solid particles through density interfaces is studied numerically when at least one of the fluids is non-Newtonian. The Carreau–Yasuda model is used to model the shear-thinning behavior of the non-Newtonian fluid. The coupled level-set and volume-of-fluid method is used to track the interface between the two fluids. It is found that the presence of shear-thinning fluids significantly affects the settling dynamics of solid spheres. For lower power index, the lighter fluid is more entrained by the sphere into the denser fluid. It is revealed that the sphere velocity after impacting the interface increases with the power index, density ratio and buoyancy jump. The shear-thinning effect of the upper and lower non-Newtonian fluids is quite noticeable and the motion of the solid sphere before crossing the interface is different to the case of Newtonian fluids. For the case of upper Newtonian fluid, there is a smaller resistance force at the interface, which causes the sphere to fall in the lower non-Newtonian fluid with about 90% of its terminal velocity. (paper)
[en] Recurrence of malignant ventricular arrhythmia is frequent in cardioverter-defibrillators related patients. The risk stratification is difficult, there are numerous electrocardiographic predictors but his sensibility and specificity are not absolute. The limit between normal and pathological is not defined, besides the complexity of ventricular arrhythmias. We expose different electrocardiographic predictors that can help to better individual risk stratification
[en] We present an experimental investigation of the different concentration build-up regimes encountered during a release of helium/air mixture in an empty enclosure without ventilation. The release is a vertical jet issuing from a nozzle located near the floor. The nozzle diameter, the flow rate and the composition of the injected mixture have been varied such that the injection Richardson number ranges from 6 x 10-6 to 190. The volume Richardson number, which gives the ability of the release to mix the enclosure content, ranges from 2 x 10-3 to 2 x 104. This wide range allowed reaching three distinct regimes: stratified, stratified with a homogeneous upper layer and homogenous. (authors)
[en] The indoor temperature in public buildings varies according to its internal loads scenario. In fact, this building typology in temperate climates is generally non-air conditioned and naturally ventilated. In order to improve indoor thermal conditions with appropriate solutions, it is necessary to study the vertical temperature profile. The main objective of this study is to show the impact of thermal stratification on thermal comfort of public buildings. The thermo-airodynamic modeling using TRNSYS(C) and CONTAM(C) have been performed in this numerical simulation study. The indoor air volume is vertically subdivided into several levels to evaluate the evolution of temperature profile taking into account the different inside-outside air exchange and air coupling between sub-zones. This study is performed in the city of Morocco that represents Mediterranean climate region with a moderate temperature. The effect of several parameters, such as indoor occupation pattern, internal lighting, sub-zones air exchange and vertical thermal stratification are studied. Numerical simulation results show that thermal stratification of buildings affects the occupant’s comfort level (paper)
[en] An algorithm for the calculation of the resistance between two arbitrary nodes in an arbitrary distance-regular resistor network is provided, where the calculation is based on stratification introduced in Jafarizadeh and Salimi (2006 J. Phys. A: Math. Gen. 39 1-29) and the Stieltjes transform of the spectral distribution (Stieltjes function) associated with the network. It is shown that the resistances between a node α and all nodes β belonging to the same stratum with respect to the α (Rαβ(i), β belonging to the ith stratum with respect to the α) are the same. Also, the analytical formulae for two-point resistances Rαβ(i), i=1,2,3, are given in terms of the size of the network and corresponding intersection numbers. In particular, the two-point resistances in a strongly regular network are given in terms of its parameters (v, κ, λ, μ). Moreover, the lower and upper bounds for two-point resistances in strongly regular networks are discussed