Water hammers seriously endanger the stability and safety of pipeline transportation systems, its protection mechanism has been a hotspot for research. In order to study change water hammer pressure caused by ball valve under different closing laws, computational fluid dynamics method was used perform transient numerical simulation times laws. The results show that faster speed in early stage, ...

CHEST, 70: 1, JULY, 1976 lation treatment. Scand J Thorac Cardiovasc Surg 7: 17-20, 1973 3 Ben-Zvi J, Hildner FJ, Chandraratna PA, et al: Thrombosis on Bjork-Shiley aortic valve prosthesis: Clinical, arteriographic, echocardiographic and therapeutic observations in seven cases. Am J Cardiol 34:538-544, 1974 4 Gramiak R, Shah P: Echocardiography of the normal and diseased aortic valve. Radiology...

the aim of this research work was to investigate on the ball filling estimation of miduk semi-autogenous (sag) mill via an utilized method. miduk copper concentrator is located in kerman province, iran, and its size reduction stage includes one gyratory crusher which feeds one sag mill (9.75 dia.(m)*3.88 length(m)) following two parallel ball mills (5dia.(m)*7lenght(m)). after sag mill, a tromm...

BACKGROUND We have used the Starr-Edwards ball (S-E) valve since 1963, the St. Jude Medical (SJM) valve since 1978, and the ATS valve, since 1993 as the first choice of mechanical valve. In this study, the results with each valve during the 40 years were investigated in single mitral valve replacement (MVR) cases. PATIENTS AND METHODS The mean age for S-E valves was 32.8+/-11.1 years old (y.o...

One hundred and six patients who left hospital after Starr-Edwards ball valve replacements have beenfollowedfor a period of 6 months tO 4 years. All patients were maintained on oral anticoagulant therapy so that a prothrombin ratio of approximately I 7:I was attained. Four patients suffered minor nose bleeds. During the period offollow-up there have been 4 patients who have suffered embolic phe...

An atrial thrombus is a relatively common echocardiographic finding in patients with mitral valve stenosis (MVS) and atrial fibrillation (AF). However, a "ball thrombus" or floating thrombus in the left atrium is a rare and specific entity associated with MVS. A 24-year-old woman with rheumatic MVS presented with complaints of progressive dyspnea and inferior limbs edema that began 23 days earl...

This paper presents an analysis of the vibration behavior a rotating machine based on signal spectrum for detecting localized defects in bearings. approach can extract characteristic frequencies related to defect from resonant frequency band signal. The technique is demonstrated tool with ball bearings (bearing number “2” and bearing “4”) under simulated crack cage. Experimental results show so...

While performing carotid angiography in a 76-year-old man, we found that the right internal carotid artery repeatedly opened and closed during the examination. The patient experienced no related neurologic events. The explanation, confirmed at surgery, was that a flap associated with an atherosclerotic plaque had acted as a ball valve.