insufficiency aims at relief of symptoms, minimisation of complications and improvement of survival. The development of prosthetic mitral rings and the establishment of reconstruction methods have led to wide application of these techniques. The ideal prosthetic valve has not yet been invented: late complications of both prosthetic mechanical valves (bleeding, thromboembolic events) and tissue ...

This paper addresses an experimental investigation in the hydrodynamic behavior of a modified slotted sieve tray. Slotted sieve tray (Push valve sieve tray) is a sieve tray that the push valves have been utilized on the tray deck to eliminate liquid gradients and non-uniformity of liquid distribution on the tray. The air-water system was used in an industrial scale experimental rig with an inte...

transluminal balloon valvuloplasty is an alternative to surgical valvotomy for congenital pulmonary valve stenosis. the aim of this study was to evaluate the long term results (to 13.5 years) of balloon pulmonary valvuloplasty. from june 1998 to january 2012, percutaneous balloon pulmonary valvuloplasty for congenital pulmonary valve stenosis was performed in 98 patients (50 males, 48 females, ...

purpose : to evaluate the efficacy and safety of pars plana ahmed valve implant combined with pars plana vitrectomy and endolaser photocoagulation for the treatment of neovascular glaucoma in patients with vitreous hemorrhage. methods : retrospectively, we evaluated the records of 18 eyes of 17 consecutive neovascular glaucoma patients who had undergone pars plana vitrectomy and pars plana ahme...

Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valve assemblies (GLV). One failure mode occurs when the GLV check valve fails and product passes into the well annulus, potentially reaching the wellhead. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure conditions, and repair and ...

In advanced energy process technologies, like the advanced pressurized circulating fluidized bed (CFB) process conceptualized by Foster Wheeler Corp., there exists a need to transport and control the flow of solids from a high pressure vessel to a low pressure vessel. Solids transport has long been done in the refinery industry and in the CFB combustor industry, but always from a low pressure v...

Secondary lymphatic valves are essential for minimizing backflow of lymph and are presumed to gate passively according to the instantaneous trans-valve pressure gradient. We hypothesized that valve gating is also modulated by vessel distention, which could alter leaflet stiffness and coaptation. To test this hypothesis, we devised protocols to measure the small pressure gradients required to op...

The objective of the present paper is a numerical analysis of the flow forces acting on spool surfaces of a pressure regulated valve. The transient, compressible and turbulent flow structures inside the valve are simulated using ANSYS FLUENT coupled with a special UDF. Here, valve inlet pressure is varied in a stepwise manner. For every value of inlet pressure, transient analysis leads to a qua...