Artificial valve replacement is a common procedure in case of heart valve disorders treatment. The main task of this prosthesis is to generate blood flow similar to flow generated by natural, human valve. Velocity distribution depends mainly on the geometry of the valve. That is why it should be analysed and modified in case to obtain the best results. The objective of this study was to numeric...

Cycles for heating and cooling have been studied in detail when it comes to thermodynamics and design. However, there are few publications on optimal operation with given equipment which is the theme of this paper. One important issue is which variable to control during operation, for example super-heating, pressure, liquid level or valve set-point. Unlike open systems the initial charge to the...

This paper investigates multiple-valve closures in a simple reservoir-valve-pipeline-valve system. Multiple closing (or opening) of valves may induce large positive or low negative pressure waves due to wave interference (superposition the waves). The effect closure can be either beneficial detrimental, with outcome being entirely dependent on position and sequence delay closures. Valves are in...

In this paper we present an algorithm to compute set-point (i.e. a position to be reached by the robot) automatically from conic features virtually placed by an operator onto the object. We then use a visual servoing algorithm to guide the gripper to its final position. We have tested this algorithm in trying to open a valve with a 6 degree of freedom robot arm, using only visual information an...

Background Bicuspid aortic valve disease (BAV) is associated with dilatation of the proximal aorta and abnormal flow patterns, particularly increased helical flow and changes in the aortic wall shear stress. These altered flow patterns may be partly responsible for the aortic dilation, though the aetiology is still unclear. Aortic valve replacement can modify the flow pattern in the proximal ao...

At present, the hydraulic systems of electric forklifts and traditional internal combustion are mostly valve-controlled speed-regulation systems, which have large throttling losses potential energy waste. To further improve energy-saving ability forklifts, forklift’s common working conditions analyzed in this paper. A loss energy-regeneration system based on pressure difference pump control is ...

OBJECTIVE To determine predictors of systolic anterior motion and left ventricular outflow tract obstruction (SAM/LVOTO) after mitral valve repair (MVRep) in patients with myxomatous mitral valve disease. BACKGROUND Mechanisms for the development of SAM/LVOTO after MVRep have been described; however, predictors of this complication have not been explored. We hypothesize that pre-MVRep transes...

Measurement of the shape and motion of the mitral valve annulus has proven useful in a number of applications, including pathology diagnosis and mitral valve modeling. Current methods to delineate the annulus from four-dimensional (4D) ultrasound, however, either require extensive overhead or user-interaction, become inaccurate as they accumulate tracking error, or they do not account for annul...

This study evaluates temperatures measured at district heating (DH) valves in manholes and their usability for non-destructively assessing the thermal performance of buried DH pipes. The was conducted as a field test which part network shut down temperature decline analysed terms absolute response time from pipe to top valve. calculated supply by drainage were good agreement, with 1% deviation....