An LRS Bianchi type-V cosmological models representing a viscous fluid distribution with a time dependent cosmological term Λ is investigated. To get a determinate solution, the viscosity coefficient of bulk viscous fluid is assumed to be a power function of mass density. It turns out that the cosmological term Λ(t) is a decreasing function of time, which is consistent with recent observations ...

An extension of the model of the gravitational scattering by moonlets in planetary rings to collisional diffusion is presented. The resulting typical propeller-shaped structures bear the chance to deduce the existence of larger (> 100 meter) embedded bodies in planetary rings. Their spatial extensions provide estimates for the size of the embedded bodies and they contain information about the p...

A previously proposed [X. Shan and H. Chen, Phys. Rev. E 47, 1815, (1993)] lattice Boltzmann model for simulating fluids with multiple components and interparticle forces is described in detail. Macroscopic equations governing the motion of each component are derived by using Chapman-Enskog method. The mutual diffusivity in a binary mixture is calculated analytically and confirmed by numerical ...

Here u, b describe the flow velocity vector and the magnetic field vector respectively, p is a scalar pressure, ν > 0 is the kinematic viscosity, η > 0 is the magnetic diffusivity, while u0 and b0 are the given initial velocity and initial magnetic field with ∇ · u0 = ∇ · b0 = 0. If ν = η = 0, (1.1) is called the ideal MHD equations. As same as the 3D Navier-Stokes equations, the regularity of ...

waste low density polyethylenes (ldpe) represent a source of energy and valuablechemicals, were pyrolysed catalytically in a batch reactor under atmospheric pressure. calciumcarbide was used as a catalyst to explore its effect on pyrolysis product distribution. the effect oftemperature, amount of catalyst and time on the yields of the pyrolysed products wasinvestigated. the effect of catalyst o...

In this research, two different diesel oil-based nanofluids were prepared and the influence of temperature nanoparticle content examined on viscosity, tribological, physicochemical features oil. The kinematic viscosity samples was experimentally evaluated based standard ASTM D445. greatest increment diagnosed at 0.7 wt% 100 °C for both nanofluids. anti-friction behavior studied utilizing a pin-...

in this article a new and an accurate method for kinematic and dynamic analysis of a parallel robot 3prs and a hybrid robot (parallel and serial) 3prs-rrp are presented, which is based on the denavit-hartenberg transformation matrix algebra. first, basic properties of various kinds of robots are compared, and then the denavit-hartenberg parameters and their table are introduced. next, the metho...

objectives: the aim of this study was to extract suitable spatiotemporal and kinematic parameters to determine how total knee replacement (tkr) alters patients’ knee kinematics during gait, using a rapid and simplified quantitative two-dimensional gait analysis procedure. methods: two-dimensional kinematic gait pattern of 10 participants were collected before and after the tkr surgery, using a ...

The model of a geometrically thin gaseous disk in the external gravitational potential is considered. The dinamics of small nonaxisymmetric perturbations in the plane of the accretion disk with dissipative effects is investigated. It is showed, that conditions of development and parameters of unstable oscillation modes in the opticaly thick accretion disk are strongly depended on the models of ...

Large-scale mantle convection, to first order, is a system driven by interior density anomalies, modulated by variable plate thickness and extreme theology variations at the top of the mantle. The rheological difference between oceanic and continental regions significantly influences the surface velocity. We apply a three-dimensional NewtonJan viscous flow model to explain the largescale presen...