the depth control systems used in iranian tractors are mechanical and they produce variable tillage depth in uneven field surface. in this research a rotary type electronic control valve was designed and constructed. by using this valve, electro-hydraulic tillage depth control system was developed and installed on the tractor. the control system was composed of: a depth sensor, a programmable l...

Ball valve is one of valves that have many applications in industry especially in gas delivery systems. This kind of valve is categorized in the on- off flow control valve. This study aims to investigate unusual application of ball valve to control fluid flow in the oil and gas industry and its destructive effect including erosion of ball and body of valve. Simulation of industrial ball valve i...

intelligent wells provide the ability for monitoring and control of downhole environment of the wells. downhole monitoring is achieved through sensors while control is realized with downhole valves. recovery from intelligent wells can be improved by proper selection of candidate wells/fields and optimizing the number, location and performance of the installed interval control valves. design cri...

Pressure control valve (PCV) is implemented in internal combustion engine to regulate crankcase pressure. In this study, the performance of a diaphragm PCV valve is investigated numerically and experimentally. Firstly, numerical simulation is carried out using commercial code to predict the flow and pressure distribution inside the valve. Furthermore, downstream and upstream pressure of the val...

Mitral valve replacement (MVR) is usually performed in two methods of running and interrupted suturing. In running method, the suturing of the valve is usually with some traction on the annulus and also there is a risk of aortic valve injury. This study was conducted to evaluate a new technique for suturing to avoid these complications and decrease the time of cardiac arrest. One hundred an...

mitral valve replacement (mvr) is usually performed in two methods of running and interrupted suturing. in running method, the suturing of the valve is usually with some traction on the annulus and also there is a risk of aortic valve injury. this study was conducted to evaluate a new technique for suturing to avoid these complications and decrease the time of cardiac arrest. one hundred and se...

Engines equipped with camless valve trains will have greater space for performance optimization. In this paper, based on the electromagnetic actuated valve train system, one-dimensional and three-dimensional simulation models on engine thermodynamic cycle and in-cylinder charge motion are established, respectively. With the application of early-intake-valve closing (EIVC) strategy，unthrottled l...

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 ...

Introduction: Rheumatic heart disease still remains one of the leading causes of congestive heart failure and death owing to valvular pathologies, in developing countries. Valve replacement still remains the treatment of choice in such patients.The aim of this study wasto analyze the postoperative outcome of  double valve replacement (Mitral and Aortic ) in patients of rheumatic heart disease. ...