The effect of chemical disinfection of the Heidbrink expiratory valve in buffered glutaraldehyde (Cidex solution) was investigated. Cidex caused stickiness and increased the opening pressure and resistance of the valve to different gas flow rates. An electrolytic type of corrosion may also have occurred. However, autoclaving of the Heidbrink valve did not appear to cause corrosion or significan...

Introduction: Methane is one of the most widely used gases in industries with a high flammability potential. This study aimed to evaluate the efficiency of ventilation systems installed on methane valve pits based on hazardous areas classification. Material and Methods: This study was implemented in a steel industry in Qom Province in 2019. The tools used in this study were a DELTA OHM pitot t...

We studied the drift of electron spins under an applied dc electric field in single layer graphene spin valves in a field-effect transport geometry at room temperature. In the metallic conduction regime (n approximately 3.5 x 10(16) m(-2)), for dc fields of about +/- 70 kV/m applied between the spin injector and spin detector, the spin valve signals are increased or decreased, depending on the ...

Of many elements influencing the performance of a rotary compressor, the valve system plays an important role. In order to evaluate the performance, some basic experimental studies were made on the discharge coefficients and the proper dimensions of the valve system. Also, since the valve systems have previously been swdied by using rather simplified models, some effort' were made in this study...

Abstract In order to improve the water shooting stability of amphibious vehicle weapon, recoil motion differential equation weapon is established by analyzing force during shooting. structure valve-controlled device and optimal strategy grey predictive fuzzy control are determined, resistance characteristic curves with or without servo valve different voltages analyzed numerically. And attitude...

In order to see whether or not the echocardiographically recorded mitral valve could reflect alterations in left ventricular pressure, simultaneous mitral valve echograms and left ventricular pressures were obtained on patients undergoing diagnostic cardiac catheterization. Attention was given to the left ventricular initial diastolic pressure (LVIDP), left ventricular end-diastolic pressure (L...

The mounting of homograft aortic valves on rigid frames often produces cusp distortion leading to mechanical dysfunction. This dysfunction can be demonstrated by a simple testing apparatus. A technique of valve mounting has been developed which consistently results in a competent valve with exact and correct cusp apposition. It is clear that the effect of different techniques of sterilization a...

BACKGROUND Aortic valve disease is associated with eccentric or concentric left ventricular (LV) hypertrophy and changes in the LV mass. The relationship between LV mass and function and the effect of LV remodeling after aortic valve replacement (AVR), in patients with aortic valve disease needs evaluation, that is largely unknown in our population. The aim of this study was to evaluate the eff...

The objective of this study is to describe the mechanism of production of the first heart sound (S). The temporal relation between the major components of S, and (1) cessation of flow across the mitral valve, (2) closure of the valve, and (3) time of peak rate of rise of left ventricular pressure (peak LV dP/dt), were investigated in open-chest dogs. Phasic flow across the mitral valve was reco...