BACKGROUND Annuloplasty ring or band implantation during surgical mitral valve repair perturbs mitral annular dimensions, dynamics, and shape, which have been associated with changes in anterior mitral leaflet (AML) strain patterns and suboptimal long-term repair durability. We hypothesized that rigid rings with nonphysiological three-dimensional shapes, but not saddle-shaped rigid rings or fle...

The transition from fully synchronized behavior to two-cluster dynamics is investigated for a system of N globally coupled chaotic oscillators by means of a model of two coupled logistic maps. An uneven distribution of oscillators between the two clusters causes an asymmetry to arise in the coupling of the model system. While the transverse period-doubling bifurcation remains essentially unaffe...

We consider the elliptic equation −∆u = f(u) in the whole R , where f is of bistable type. It is known that there exists a saddleshaped solution in R. This is a solution which changes sign in R and vanishes only on the Simons cone C = {(x, x) ∈ R×R : |x| = |x|}. It is also known that these solutions are unstable in dimensions 2 and 4. In this article we establish that when 2m = 6 every saddle-s...

We have characterized the annular geometry of mitral and tricuspid valves in elite athletes using 3-D echocardiography. found that exercise-induced remodeling atrioventricular annuli comprises a disproportionate dilation dimensions increased leaflet tenting both valves. Moreover, we demonstrated more pronounced saddle shape annulus without regurgitation, which was not present those who had mild...

In this paper a new isolating system is introduced for short to mid-rise buildings. In comparison to conventional systems such as LRB and HRB, the proposed system has the advantage of no need to cutting edge technology and has low manufacturing cost. This system is made up of two orthogonal pairs of pillow-shaped rollers that are located between flat bed and plates. By using this system in two ...

car body lightening and crashworthiness are two important objectives of car design. due to their excellent performance, composite materials are extensively used in the car industries. in addition, reducing the weight of vehicle is effective in decreasing the fuel consumption. hat shape energy absorber is used in car’s doors for side impact protection. the aim of these numerical models and exper...

The paper deals with an efficient solution technique to large– scale discretized shape and topology optimization problems. The efficiency relies on multigrid preconditioning. In case of shape optimization, we apply a geometric multigrid preconditioner to eliminate the underlying state equation while the outer optimization loop is the sequential quadratic programming, which is done in the multil...