The observed properties of valves in collecting lymphatic vessels include transmural pressure-dependent bias to the open state and hysteresis. The bias may reduce resistance to flow when the vessel is functioning as a conduit. However, lymphatic pumping implies a streamwise increase in mean pressure across each valve, suggesting that the bias is then potentially unhelpful. Lymph pumping by a mo...

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...

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...

To monitor the gas and solid streams in a downcomer of a J-valve in a CFB, the simultaneous measurement technique using the oxygen gas tracer, the hot particle tracer and the pressure drop was developed. By using this novel measurement technique, the dependence of the solid flow on the gas flow in the moving bed in the downcomer of J-valve was investigated. The pressure profile and the pressure...

We have designed and fabricated the first single-wafer proportional micro control valve with built-in capacitive displacement sensing. The displacement sensor can facilitate high-speed active proportional control of gas flow through the valve. This is an essential requirement for non-invasive blood pressure waveform monitoring based on following the arterial pressure with a counter pressure. We...

INTRODUCTION Double chambered right ventricle is a rare congenital cardiac anomaly in which the right ventricle is divided into two chambers by an anomalous muscle bundle. The diagnosis of this disorder is difficult in adults. Calcification of the tricuspid valve is extremely rare, and very few cases have been reported. Most cases of tricuspid valve calcification had a congenital disorder with ...