The aim of this paper is to study and compare the dynamics of two classes of periodic point free homeomorphisms of the open annulus, homotopic to the identity. First, we consider skew products over irrational rotations (often called quasiperiodically forced monotone maps) and derive a decomposition of the phase space that strengthens a classification given by J. Stark. There exists a sequence o...

Recent X-ray observations of microquasars and Seyfert galaxies reveal the broad emission lines in their spectra, which can arise in the innermost parts of accretion disks. A theoretical analysis of observations and their interpretations were discussed in a number of papers. We consider a radiating annulus model to simulate spectral line shapes. That is a natural approximation for narrow emittin...

Stable isotope (615N and 6°C) values of individual tooth annuli of female Steller sea lions (n = 120) collected from the 1960s through the 1980s were used for retrospective analyses of temporal changes in food webs in the Gulf of Alaska and North Pacific Ocean. We also examined isotopically contour feathers of tufted puffins (n = 135) and crested auklets (n = 37) through this period to test for...

We conjecture that the roots of a degree-n univariate complex polynomial are located in a union of n − 1 annuli, each of which is centered at a root of the derivative and whose radii depend on higher derivatives. We prove the conjecture for the cases of degrees 2 and 3, and we report on tests with randomly generated polynomials of higher degree. We state two other closely related conjectures co...

We conjecture that the roots of a degree-n univariate complex polynomial are located in a union of n − 1 annuli, each of which is centered at a root of the derivative and whose radii depend on higher derivatives. We prove the conjecture for the cases of degrees 2 and 3, and we report on tests with randomly generated polynomials of higher degree. We state two other closely related conjectures co...

The accurate prediction of the fluid dynamics and hydraulics axial or helical flow non-Newtonian drilling fluids in annuli is essential for determination effective management wellbore pressure during operations. Previous studies have shown that losses velocity distributions are highly influenced by rheological properties fluid, inner pipe rotary speed eccentricity. However, many literature deve...

In this paper, we will report a recent study about moduli spaces of branched and complete minimal surfaces in Euclidean space of genus one with two ends and total curvature −4π.

It is known that any infinite periodic frieze comes from a triangulation of an annulus by Theorem 4.6 [K. Baur, M. J. Parsons and Tschabold, Infinite friezes, European Combin. 54 (2016) 220–237]. In this paper, we show each determines in essentially unique way. Since pair study such pairs how they determine other. We associated module categories the growth coefficient friezes terms modules as w...