This paper analyzed the characteristics of managed pressure drilling (MPD) technology and impact of wellhead back pressure on the wellbore annulus pressure profile, and found that the application of this technology provides room for improvement to the current casing program design. Meanwhile, the equivalent density of drilling fluid in wellbore annulus needs to consider the impact of back press...

This paper presents a boundary integral equation method for computing numerical conformal mapping of bounded multiply connected region onto an annulus with spiral slits region and its inverse. The method is an extension of the author’s method for computing the Annulus with circular slits map of bounded multiply connected regions (see [Sangawi, A. W. K., Murid, A. H. M., Nasser, M. M. S.: Annulu...

This communication investigates the unsteady flow of viscous incompressible fluid through porous medium induced by periodically heated half filled concentric cylindrical annulus placed horizontally. The boundaries of the annulus are rotating periodically with different angular velocities in the same or opposite directions about their common axis. The governing equations are expressed in terms o...

The detailed analytical and numerical analysis of the electron spectrum, persistent currents, their densities for an annulus placed in a constant magnetic field (Corbino disk geometry) is presented. We calculate current density profiles study dependence on inner outer radii annular. evolution currents track emergence decay different limiting cases such geometry, starting from nanodot ending by ...

We find Weyl upper bounds for the quantum open baker’s map in semiclassical limit. For number of eigenvalues an annulus, we derive asymptotic bound $\mathcal O(N^\delta)$, where $\delta$ is dimension trapped set and $(2 \pi N)^{-1}$ parameter, which improves upon previous result O(N^{\delta + \epsilon})$. Furthermore, a with explicit dependence on inner radius annulus maps Gevrey cutoffs.

This result has also been proved by Bowditch [2], using very different methods. We discuss these differences at the end of this introduction. The terminology used is standard (from [11] and [17]). The importance of splitting groups along infinite cyclic subgroups is well known from the work of Paulin [13], Rips and Sela [14] and Sela [18]. If G has an infinite cyclic subgroup H such that e(G,H)...

We study theoretically magnetohydrodynamic (MHD) motion of a binary electrolyte in a concentric annulus subjected to a uniform, axial magnetic field. The annulus’ cylindrical surfaces serve as electrodes. When a potential difference is imposed across the cylindrical electrodes, radial electric current flows in the solution and interacts with the axial magnetic field to induce a Lorentz body for...

OBJECTIVES Our aim was to describe the use of balloon aortic valvuloplasty (BAV) to select proper transcatheter heart valve (THV) size. BACKGROUND Transesophageal echocardiogram (TEE) measurement alone of the aortic annulus may not be adequate to select a THV size. BAV can more accurately size the aortic annulus. We report our experience using this strategy in patients undergoing THV implanta...