The shearing sheet model of a galactic disk is studied anew. The theoretical description of its dynamics is based on three building blocks: Stellar orbits, which are described here in epicyclic approximation, the collisionless Boltzmann equation determining the distribution function of stars in phase space, and the Poisson equation in order to take account of the self–gravity of the disk. Using...

Non–linear effects in the dynamical evolution of a shearing sheet made of stars are studied. First the implications of hitherto neglected non–linearities of the Boltzmann equation for the dynamical evolution of the shearing sheet are investigated. Using a formalism developed previously on the basis of the linearized Boltzmann equation it is demonstrated that the inclusion of the non–linear term...

I consider the nonaxisymmetric linear theory of an isothermal magnetohydrodynamic (MHD) shear flow. The analysis is performed in the shearing box, a local model appropriate for a thin disk geometry. Linear perturbations in this model can be decomposed in terms of shearing waves (shwaves), which appear spatially as plane waves in a frame comoving with the shear. The time dependence of these wave...

In this paper, a Shearing Invariant Texture Descriptor (SITD) is proposed, which is a theoretically and computationally simple method based on the Rotation invariant Local Binary Pattern (Rot-LBP) descriptor. In real-world applications using flatbed scanners, such as paper texture fingerprinting, it’s common for a sheet of paper to rotate during the image acquisition process. Because the rotati...

The activation energies associated with the formation of a superlattice intrinsic stacking fault (SISF) from an antiphase domain boundary (APB) and the formation of a superlattice extrinsic stacking fault (SESF) from a complex stacking fault (CSF) in g 0 phase of Ni-based superalloys are calculated using a microscopic phase field dislocation model in combination with the nudged elastic band (NE...

Biomass size reduction is an important step in biomass densification and this article reviews reduction studies. Hammermilling technology had the advantage of low maintenance over other methods including crushing, shearing and rollermilling. A review of equipment design parameters showed that hammermill tip speed, power requirements, grinding rate, screen size, and clearance affect performance ...

Fluctuation-driven particle flux is greatly reduced in the plasma radial region where zonal flows are present in the H-1 toroidal heliac. This occurs without reduction in the fluctuation level. Statistical properties of fluctuations are significantly modified in this region. It is shown that the randomization of phases of coherent structures by zonal flows is responsible for the observed effect...

Based on a linear systems approach, we derive the Wigner distribution function (WDF) of a 4f imager with a volume holographic three-dimensional pupil; then we obtain the WDF of the volume hologram itself by using the shearing properties of the WDF. Two common configurations, plane and spherical wave reference volume holograms, are examined in detail. The WDF elucidates the shift variant nature ...

Rock strata in a coal mining environment are essentially bedded in nature and hence exhibit specific load-deformation characteristics. Mining may induce shearing as well as separation along the bedding planes which may result in bending and subsequent fracturing of the rock layer. This on the other hand may substantially change the in situ fluid flow properties of the rock mass, such as permeab...

This paper presents a novel image watermarking resynchronization technique in discrete wavelet trans-form (DWT) domain. Rotation and shearing attacks desynchronizing watermark model in DWT domain are given respectively. According to these models, two corresponding watermarking resynchronization algorithms are proposed. The ideal watermark can be extracted from the resynchronized watermarked ima...