Annular patterns with a high degree of zonal symmetry play a prominent role in the natural variability of the atmospheric circulation and its response to external forcing. But despite their apparent importance for understanding climate variability, the processes that give rise to their marked zonally symmetric components remain largely unclear. Here the authors use simple stochastic models in c...

This paper presents modeling of annular patch antenna. The S and Z parameters of an Annularpatch Microstrip antenna are investigated and optimization. The optimization is performed byvarying the inner and outer radius of annular Ring. The impedance and radiation characteristicsof annular patch antenna are examined and compared. It is able to achieve a return loss lessthan -36 dB...

The operating characteristics of a linear-geometry (open electron drift) Hall thruster are revisited under improved vacuum conditions, in order to eliminate possible channel wall contamination from oil diffusion-pump vapors. A comparison is made between cases in which the thruster is operated with channel walls fabricated from plate diamond, and from boron nitride. These studies reveal a new op...

OBJECTIVES Annular pancreas is a rare congenital anomaly characterized by pancreatic tissues wrapping completely or incompletely around the descending duodenum. In most patients with annular pancreas, onset occurs in early childhood. Adults with annular pancreas are prone to duodenal ulcers and pancreatitis. Intraductal papillary mucinous neoplasm (IPMN) is a type of papillary mucinous secretor...

In this paper, the exact analytical and numerical solutions for rotating variable-thickness annular disk are presented. The inner and outer edges of the rotating variable-thickness annular disk are considered to have free boundary conditions. Two different annular disks for the radially varying thickness are given. The numerical Runge-Kutta solution as well as the exact analytical solution is a...

Both clinical and pathologic findings must be considered when diagnosing figurate skin lesions, which are often seen in routine practice. Although a skin biopsy may sometimes be diagnostic, more often the information provided is nonspecific. In an attempt to offer an approach to diagnosing these dermatoses, we have classified annular lesions according to the presence of lymphocytic, neutrophili...

BACKGROUND Little is known about the impact of tricuspid annuloplasty (TAP) on annular dynamics. We assessed tricuspid annular dynamics using 3-D transesophageal echocardiography (3D-TEE) before and after TAP with different types of prosthetic ring. METHODS AND RESULTS 3D-TEE of the tricuspid valve was acquired in 30 patients (TAP with rigid ring [RR], n=8; TAP with flexible ring [FR], n=10; ...

BACKGROUND Functional tricuspid regurgitation (TR) is increasingly recognized as a source of morbidity. Current repair strategies focus on annular remodeling because annular dilatation is common in patients with TR. Although papillary muscle (PM) displacement is recognized in functional mitral regurgitation, its role in TR is less well characterized. The objective of this in vitro study was to ...

BACKGROUND remodeling of the mitral annulus contributes to progression of mitral regurgitation (MR). In patients with moderate-to-severe MR, short-term treatment with β-blockers has been shown to increase left ventricular (LV) end-diastolic and end-systolic volume, and this could deleteriously increase mitral valve annular dimensions. The objective of this study was to quantify the effects of a...