Diagnostic and therapeutic problems commonly arise in patients with rheumatic heart disease despite the use of all available clinical data, including electrocardiographic and roentgenographic studies. The deficiencies of the conventional aids have become more apparent with attempts to define the physiological significance of mitral valve lesions. Since its introduction by Cournand and associate...

quadricuspid aortic valve (qav) is an uncommon congenital anomaly which was an incidental finding during surgery or autopsy in the past. we present the case of a 44-year-old woman with moderately severe aortic regurgitation due to unequal cusp size qav diagnosed via transesophageal echocardiography. due to echocardiographic imaging improvement, the diagnosis of qav is now easier and earlier tha...

In this paper, a special technique is studied by using the orthogonal Chebyshev polynomials to get approximate solutions for singular and hyper-singular integral equations of the first kind. A singular integral equation is converted to a system of algebraic equations based on using special properties of Chebyshev series. The error bounds are also stated for the regular part of approximate solut...

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...

Introduction: It is well-documented that right-sided heart dysfunction and significant tricuspid valve regurgitation (TVR) have adverse effects on patient outcomes after left-sided heart valve surgery. Therefore, the evaluation of right ventriclular (RV) function and TR severity in patients who had undergone mitral valve replacement (MVR), associated with/without concomitant su...

Ultrasonic echocardiograms from the anterior cusp of the mitral valve have been obtained in 75 patients with aortic regurgitation in whom there was haemodynamic or surgical confirmation, or both, of the state of the mitral valve. Coincident mitral stenosis could be recognized from the echocardiogram in all cases by a slow diastolic closure rate and widening of the echo from the anterior mitral ...

In present work ,a boiler turbine plant is presented as a 2x2 MIMO system with high multivariable interaction having two manipulated variables namely the governor valve position and the fuel flow rate and two control variables namely generated electric power and the steam pressure. The controller for this plant has been designed using conventional PID and MPC technique by first investigating th...

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...

‎This paper presents two main results that the singular values of the Hadamard product of normal matrices $A_i$ are weakly log-majorized by the singular values of the Hadamard product of $|A_{i}|$ and the singular values of the sum of normal matrices $A_i$ are weakly log-majorized by the singular values of the sum of $|A_{i}|$‎. ‎Some applications to these inequalities are also given‎. ‎In addi...