Since most complications related to operation of prosthetic heart valves are due to disturbances of flow, its hydrodynamic characterization is a useful aid in the design of new prostheses. Besides durability and biological response to implant, these prostheses should provide a favorable hemodynamic profile, considering that there is a great clinical interest focused on the haemolysis of blood. ...

This is an anatomic study of 96 hearts with straddling or displaced atrioventricular (AV) valves and orifices. In the complete form, both the annulus and the peripheral connections of either AV valve straddle a ventricular septal defect (VSD) and connect to both ventricles. In the annular form, only the annulus, and in the peripheral type only the peripheral connections of the valve are found i...

Hydraulic valves are key components of fluid power systems. They control the flow rate and pressure in hydraulic lines, actuator motion, direction. Valves that or can be divided into two main categories: spool-type valves, where similar to piston inside a sleeve with orifices; seat-type which poppet seat opens closes flow. Forces induced on valve during oil crucial valve’s operational capabilit...

BACKGROUND Recently, renewed interest in allograft and stentless "freehand" bileaflet xenograft mitral valve replacement has arisen. The variability of human papillary tip anatomy and scarcity of donors limit allograft availability, making xenograft mitral valves an attractive alternative; however, these valves require new surgical implantation techniques, and assessment of their hemodynamics a...

This paper presents entropy generation minimisation model of combined heat and power system. The turbine control valves and heater throttle valves were analysed. The high-pressure control valves regulate the mass flow rate of steam into the turbine, whereas the intermediate-pressure and lowpressure control valves the steam pressure of the turbine extracts 3 and 5. The steam of the turbine extra...

In water supply systems, One of the most important components as safety unit and the current controller (Switching flow and regulate the amount of flow) used in the arrangement of lines of water. In this study, according to multiple ponds in Tanguiyeh dam water pipeline to industrial and mining company Gol Gohar Sirjan Butterfly valve used in these ponds using Fluent software simulation has bee...

OBJECTIVE To test the hypothesis that diastolic mitral annular motion velocity, as determined by Doppler tissue imaging and left ventricular diastolic flow propagation velocity, is related to the histological degree of heart transplant rejection according to the International Society of Heart and Lung Transplantation (ISHLT). METHODS In 41 heart transplant recipients undergoing 151 myocardial...

This paper describes two steam turbine governor valve failures in the same installation, the troubleshooting that determined the root cause, and the new valve designed to prevent similar failures. The original governor valve design had been used successfully for many years in large multistage, multivalve steam turbines, but apparently was not reliable at the high steam pressures employed today....