we report engineering experiences from the critical task of relief well installation under high artesian flow conditions at the downstream toe of the karkheh earth dam, iran. due to the establishment of excessive uplift pressure at the downstream toe of the karkheh dam, installation of a series of new relief wells was considered to permanently relieve part of these pressures. the mentioned upli...

The mining emulsion pump is mainly used on a fully mechanized coal face, but it rarely other occasions, so research its loading test method relatively limited. This paper proposes the application of digital relief valve to test. In addition, small number plungers in will lead large flow pulsation and pressure pulsation, nominal different types pumps varies greatly. These factors deficiency trad...

AIMS Hypertension is a frequent finding in patients with aortic stenosis (AS). However, controversial data about the influence of systemic blood pressure on the quantification of AS have been published. METHODS AND RESULTS Various models of AS (plates and biological valves) were studied in an in vitro circuit. Valve areas were calculated with the Doppler continuity equation and the Gorlin for...

A better course of the disease after implantation of a low-pressure valve in patients with idiopathic normal pressure hydrocephalus normally comes at the cost of a distinctly higher rate of overdrainage. Can combining an adjustable valve with a gravity unit produce optimization of treatment results? In a prospective observation of the course of the disease, 18 patients with idiopathic normal pr...

Using the enterprise’s valve as the research object, the research shows the characteristics of the flow field and noise of the valve. The theory of LES and Lighthill acoustic analogy is applied to study the flow noise characteristics of 100% opening and 70% opening of valve in the same flow. The result shows that the region of variation about pressure and velocity is concentrated in the valve s...

Mitral valve closure during cardiopulmonary resuscitation may result from direct cardiac compression. An alternative hypothesis is that with a rise in intrathoracic pressure, mitral valve closure can occur but may be influenced by whether the lungs are inflated or deflated. To test this hypothesis, we placed a large-bore cannula into the thoraces of 11 dogs. Intrathoracic pressure was changed b...

In internal combustion engines, exhaust valve and its seat gain considerable temperature as the hot gases exit through them. So, the rate of heat transfer should be under control. In this study, the contact heat transfer coefficient has been estimated. An experimental study on an Air-Cooled internal combustion engine cylinder head has been considered. Using the measured temperatures of sensors ...

The mean pressure drop across the mitral valve and atrioventricular pressure half-time were measured noninvasively by Doppler ultrasound in 40 normal subjects, in 17 patients with mitral regurgitation, 32 patients with mitral stenosis and 12 with combined stenosis and regurgitation. In normal subjects pressure half-times were 20--60 msec, in patients with isolated mitral regurgitation 35--80 ms...

Pressure relief valves and vents in the petrochemical industry are often the last line of defense in averting a major accident. Recent design standards (API 520/521) have been developed which have reduced the recommended exit velocities for hydrocarbons from pressurized storage. There are computer models available which predict the release and dispersion of high velocity gas jets. In some insta...

A double coil magnetorheological (MR) valve with an outer annular resistance gap was designed and prototyped. The finite element modeling and analysis of double coil MR valve were carried out using ANSYS/ Emag software, and the optimal magnetic field distribution and magnetic flux density of the double coil MR valve were achieved. The mechanism of the pressure drop was studied by building a mat...