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...

Due to growing concerns over environmental protection, economic and environmentally responsible power dispatching has become a hot topic in the field of system control. Multi-objective optimization minimizes fuel costs pollution emissions without violating operational constraints. To solve this problem, MOP is decomposed into individual objects via weighted sum method, Newton’s method used tack...

This paper presents a study of dynamic characteristics of spring loaded relief valve and the turbulent flow of water through it by using CFD in 2-Dimensions. Mesh deformation due to the fluid-solid interaction between the valve disc and the surrounding fluid and CEL expressions determined by solving a dynamics equation of forces acting on the valve disc, are used to account for the motion of th...

Certification tests currently employed by some industrialized nations to certify respirators require that when challenged with air flow at a constant suction head of 25 mmH2O, the leakage into the facepiece from the exhalation valve(s) should not exceed 30 ml min(-1). However, the test alone might not reflect the leakage rate under different levels of vacuum. To study the characteristics of lea...

Segmenting the mitral valve during closure and throughout a cardiac cycle from four dimensional ultrasound (4DUS) is important for creation and validation of mechanical models and for improved visualization and understanding of mitral valve behavior. Current methods of segmenting the valve from 4DUS either require extensive user interaction and initialization, do not maintain the valve geometry...

This is especially true for exhaust valves, due to the high temperature environment to which the valve is exposed. In a paper presented at the GMRC 2007 Gas Machinery Conference[1], it has been shown that statistical techniques and histograms of valve vibration data can be used to identify valve faults that can lead to valve failures. This paper will discuss refinements made to the statistical ...

Power system operation involves some kind of optimization for ensuring economy, security and stability. Economic load dispatch is one such optimization problems and it is applied for minimizing the total fuel cost. Optimizing the fuel cost is done by properly setting the real power generation from the generators in a power system. Differential evolution is a simple and efficient evolutionary al...

Renal failure is associated with aortic valve calcification. Using our rat model of uremia-induced reversible aortic valve calcification, we assessed the role of apoptosis and survival pathways in that disease. We also explored the effects of raloxifene, an estrogen receptor modulator, on valvular calcification. Gene array analysis was performed in aortic valves obtained from three groups of ra...

  Introduction: Aortic valve sclerosisis considered as a manifestation of coronary atherosclerosis. Recent studies demonstrated an association between aortic valve sclerosis and obstructive coronary artery disease. The purpose of this study was to evaluatethe correlation betweenaortic valve sclerosis andobstructive coronary artery disease and the extent of coronary artery disease in patients ho...