In this paper I will review the dynamical models that attempt to explain the outflows in QSOs and Seyfert galaxies that are responsible for the blue shifted absorption lines observed in some of these objects. Most models face the difficulty that the absorbing gas appears to consist of very small, low filling factor clouds, that are likely to be hydrodynamically unstable, and require an interclo...

Many active matter systems are known to perform L\'{e}vy walks during migration or foraging. Such superdiffusive transport indicates long-range correlated dynamics. These behavior patterns have been observed for microswimmers such as bacteria in microfluidic experiments, where Gaussian noise assumptions insufficient explain the data. We introduce \textit{active L\'evy swimmers} model behavior. ...

Abstract. In this paper, a Cascaded Lattice Boltzmann Method with second order slip boundary conditions is developed to study gas flows in a microchannel in the slip and transition flow regimes with a wide range of Knudsen numbers. For the first time the effect of wall confinement is considered on the effective mean free path of the gas molecules using a function with nonconstant Bosanquet para...

Trapped substances between a two-dimensional (2D) crystal and an atomically flat substrate lead to the formation of bubbles. Their size, shape and internal pressure are determined by the competition between van der Waals attraction of the crystal to the substrate and the elastic energy needed to deform it, allowing to use bubbles to study elastic properties of 2D crystals and conditions of conf...

Let Γ̄ be the Picard modular group of an imaginary quadratic number field k and let D be the associated symmetric space. Let Γ ⊂ Γ̄ be a congruence subgroup. We describe a method to compute the integral cohomology of the locally symmetric space Γ\D. The method is implemented for the cases k = Q(i) and k = Q( √ −3), and the cohomology is computed for various Γ.

Throughout this brief note all groups are assumed to be abelian p-primary, written additively as is customary when regarding the group structure. Since we shall deal exclusively only with p-torsion abelian groups, for some arbitrary but a fixed prime p, there should be no confusion in future removing the phrase ”is an abelian p-group”. Concerning the terminology, under the term a separable grou...

The fundamental issue of interactions between lipid bilayers is addressed experimentally and theoretically. We report high-resolution x-ray scattering data for bilayers composed of three different kinds of phosphatidylcholine lipids. These data yield the interbilayer water spacing fluctuation s , as well as the traditional osmotic pressure P , both as functions of the lamellar repeat spacing D ...

An axisymmetric MHD model is examined analytically to illustrate some key aspects of the physics of hot and magnetized outflows which originate in the near environment of a central gravitating body. By analyzing the asymptotical behaviour of the outflows it is found that they attain a variety of shapes such as conical, paraboloidal or cylindrical. However, non cylindrical asymptotics can be ach...

The ground reaction curve (GRC) is a vital component of the convergence-confinement method, which possesses many applications in the underground space designs. It defines a relation between the tunnel wall deformations and the ground pressure acting on the tunnel walls. Generally, GRC includes descending and ascending branches. According to many researchers, the descending branch trend for the ...

The strength and ductility of concrete improve under multi-axial compressive stress due to confinement effect. Some parameters are effective for considering the confinement in concrete and various stress-strain models were developed by different researchers. Longitudinal and transverse reinforcement steels can influence on confinement in reinforced concrete members. In this paper, various stres...