Results 21 to 30 of about 4,930,166 (237)
Covering polygonal annuli by strips [PDF]
, 2007 In 2000 Bezdek asked which plane convex bodies have the property that whenever an annulus, consisting of the body less a sufficiently small scaled copy of itself, is covered by strips, the sum of the widths of the strips must still be at least the ...
Wisewell, L., White, S.A.
core +2 more sources
New Model for the Assessment of Transcatheter Aortic Valve Replacement Devices in Sheep
Journal of Investigative Surgery, 2022 Background Transcatheter aortic valve replacement (TAVR) is an effective therapy in treating high-risk patients suffering from aortic stenosis. Animal models used to evaluate safety and efficacy of TAVR devices prior to clinical use lack a stenotic ...
John P. Carney +6 more
doaj +1 more source
Aortic annulus ellipticity and outcomes after transcatheter aortic valve implantation. [PDF]
, 2023 BACKGROUND Elliptical shape of the aortic annulus has been associated with an increased risk of device failure after transcatheter aortic valve implantation (TAVI) compared with a circular annular shape.
Lanz, Jonas +11 more
core +1 more source
Frontiers in Cardiovascular Medicine, 2022 ObjectiveThe objective of this study was to observe the safety and efficacy of electrophysiological mapping following the Cox-Maze IV procedure and to investigate whether a correlation exists between recurrence of atrial fibrillation (AF) with the ...
Zhishan Sun +7 more
doaj +1 more source
Existence of non-contractible periodic orbits for homeomorphisms of the open annulus [PDF]
Mathematische Zeitschrift, 2019 In this article we consider homeomorphisms of the open annulus $\mathbb{A}=\mathbb{R}/\mathbb{Z}\times \mathbb{R}$ which are isotopic to the identity and preserve a Borel probability measure of full support, focusing on the existence of non-contractible periodic orbits.
Conejeros, Jonathan, Tal, Fábio Armando
openaire +2 more sources
Solutions of two-point boundary value problems via phase-plane analysis
Electronic Journal of Qualitative Theory of Differential Equations, 2016 We consider period annuli (continua of periodic solutions) in equations of the type $x''+g(x)=0$ and $x''+f(x) x'^2 + g(x)= 0,$ where $g$ and $f$ are polynomials.
Svetlana Atslega, Felix Sadyrbaev
doaj +1 more source
Frontiers in Energy Research, 2022 The integrity of cement sheath seals in casing connection sections is an important part of preventing air channelization. It is of great significance to evaluate the failure mechanism of cement sheath seals in casing connection sections under complex ...
Zhong Li, Yi Wu, Renjun Xie, Zhiqiang Wu
doaj +1 more source
S-shaped bifurcations in a two-dimensional Hamiltonian system
Electronic Journal of Qualitative Theory of Differential Equations, 2021 We study the solutions to the following Dirichlet boundary problem: \begin{equation*}\frac{d^2x(t)}{dt^2}+\lambda f(x(t))=0,\end{equation*} where $x \in \mathbb{R}$, $t \in \mathbb{R}$, $\lambda \in \mathbb{R}^+$, with boundary conditions: \begin ...
Andre Zegeling, Paul Zegeling
doaj +1 more source
Rotation sets and monotone periodic orbits for annulus homeomorphisms [PDF]
Commentarii Mathematici Helvetici, 1992 This paper is about the existence of periodic points for homeomorphisms of the annulus and contains an affirmative answer to a question posed by \textit{G. R. Hall} [Contemp. Math. 81, 135--152 (1988; Zbl 0677.58026)]. Using Thurston-Nielsen theory for surface homeomorphisms, the following theorem is proved: If \(f\) is an orientation and boundary ...
openaire +2 more sources
The bifurcation of limit cycles of two classes of cubic systems with homogeneous nonlinearities
Electronic Journal of Qualitative Theory of Differential Equations, 2019 In this paper, we study the bifurcation of limit cycles of the periodic annulus of two classes of cubic isochronous systems. By using complete elliptic integrals of the first, second kinds and the Chebyshev criterion, we show that the upper bound for ...
Yi Shao, Yongzeng Lai, Chunxiang A
doaj +1 more source