The purpose of this study is both theoretically and experimentally to present the deformation and stress of a flexible discharge ring valve, and to get design concept on this type valve and its backer plate. The strain measurements of the valve were carried out on the strain gauges mounted at the root of the spoke and at the transition point in the spoke. The deflection measurement was also per...

Pulmonary autograft valve replacement has been simulated by implanting the pulmonary valve into the aortic position of the same cadaver heart from both human and porcine sources. The forces acting on the pulmonary valve leaflets have been calculated on the basis of a triaxial ellipsoid mathematical model. These forces on the pulmonary autograft valve were shown to be essentially similar to thos...

We recently shown, using tight-binding calculations, that nonequilibrium valley polarization can be realized in graphene, when the current is injected through ”valley filter”: a ballistic point contact with zigzag edges. Here we demonstrate, that the effect is surprisingly robust against changing the crystallographic orientation of the filter axis. Namely, the output current remains polarized u...

BACKGROUND The closure sound of the ATS bileaflet mechanical valve is said to be quieter than that of the other mechanical valves. However, the reasons for this are still unknown. In this study, we investigated the reasons for the quietness of the ATS valve closure sound. PATIENTS AND METHODS The valve closure sound was evaluated in 70 patients and in another 70 patients in whom the SJM valve...

Mitral valve regurgitation is a relatively common and important heart valve lesion in clinical practice and adequate assessment is fundamental to decision on management, repair or replacement. Disease localised to the posterior mitral valve leaflet or focal involvement of the anterior mitral valve leaflet is most amenable to mitral valve repair, whereas patients with extensive involvement of th...

Transcatheter aortic valve implantation is a novel treatment for severe aortic valve stenosis. Due to the recent use of this technology and the procedural variability, there is very little data that quantify the hemodynamic consequences of variations in valve placement. Changes in aortic wall stresses and fluid retention in the sinuses of Valsalva can have a significant effect on the clinical r...

Economic load dispatch (ELD) is an important optimization task in power system. It is the process of allocating generation among the committed units such that the constraints imposed are satisfied and the energy requirements are minimized. There are three criteria in solving the economic load dispatch problem. They are minimizing the total generator operating cost, total emission cost and sched...

Optimal distribution of power among generating units to meet a specific demand subject to system constraints is an ongoing research topic in the power system community. The problem, even in a static setting, turns out to be hard to solve with conventional optimization methods owing to the consideration of valve-point effects, which make the cost function nonsmooth and nonconvex. This difficulty...

the morphologic characteristics of the mitral valve (i.e., simple mitral valve prolapse vs. flail leaflet or the presence of severe myxomatous infiltration), cannot yet be analyzed. Recently, it has been suggested that mitral valve prolapse is uniformly a good prognosis (3). It is unclear how these various components of the clinical presentation of patients with mitral valve diseases contribute...