OBJECTIVE The Delta valve is a pressure differential valve with a siphon control device. The valve mechanism is normally closed, but is designed to open in response to positive ventricular pressure, thereby avoiding overdrainage of cerebrospinal fluid (CSF). As a result, the incidence of subdural fluid collections as well as postural symptoms is purportedly reduced. In addition, the valve might...

The hot gases produced by the internal combustion engines passes through the exhaust valve and causes high temperatures in the exhaust valve and its seat. To avoid damaging the exhaust valve, heat must be transferred from the valve to its seat during the contact they make at the opening and closing cycle. Heat transfer rate from the exhaust valve to its seat is a function of many factors. One o...

background: considering suggested formula in the references and pcwp measured by catheterism, in the present study the relation between pulmonary capillary wedge pressure (pcwp) measured the flow velocity of mitral valve and mitral annulus motion through tissue doppler imaging is evaluated methods: 52 cases of severe ms were admitted for balloon mitral valvolotomy (bmv) are included in this stu...

This research includes both experimental and CFD investigation in the hydrodynamic behavior of a new type of column tray introduced as “Concap” tray. The proposed column tray is used in contactor columns especially in stripping columns. The hydrodynamics of this Concap tray is investigated in a 1.2m in diameter column. Using air-water system, the experiments were performed for different liquid ...

this research includes both experimental and cfd investigation in the hydrodynamic behavior of a new type of column tray introduced as “concap” tray. the proposed column tray is used in contactor columns especially in stripping columns. the hydrodynamics of this concap tray is investigated in a 1.2m in diameter column. using air-water system, the experiments were performed for different liquid ...

In order to assess left ventricular function in patients with rheumatic mitral stenosis, left ventricular function curves (plotting stroke work index vs left ventricular end-diastolic pressure) were constructed using angiotensin to augment, and nitroprusside to reduce, afterload. Hemodynamic responses to these alterations in afterload were measured. Resting ejection fractions and qualitative as...

ii) The control valve Manufacturer can only state the Inherent valve characteristics, which refer to the flowrate (F) – valve travel position (m or Z) relationship, when the pressure drop across the control valve (DPV) is constant. Note that the pressure drop across the control valve (DPV) can be almost constant only if the piping system pressure drop (DPS) is concentrated at the control valve ...

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 We reviewed the rare ocular findings of Sturge-Weber syndrome (SWS) and the results of implantation of the Ahmed valve in cases associated with glaucoma. METHODS Seven patients (range 18 to 52 years) diagnosed as SWS were reviewed as clinical findings over two years. An anterior chamber maintainer was placed in patients with glaucoma to maintain stable intraocular pressure and minimiz...