AIMS To determine whether mitral annular calcification and aortic valve calcification, with or without stenosis, are expressions of atherosclerotic disease. METHODS The incidence of atherosclerotic risk factors was analysed in patients with mitral annular calcification and aortic valve calcification and in control patients from a prospective echocardiographic database of 8160 consecutive pati...

When a natural gas pipeline ruptures, the adjacent automatic line control valves (ALCVs) should close quickly to prevent leakage or explosion. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in ALCV action. If the DPS is not properly adjusted, the ALCV may mistakenly close or it may not take any action at proper time. This study focused on...

In this paper, a hierarchical control architecture incorporating a novel dual-arm impedance controller is proposed and experimentally evaluated in a valve turning setup. Proposed control architecture incorporates various control/interface modules to render a desired interaction performance in our intrinsically compliant humanoid robot, COMAN: the sensing module provides the manipulation module ...

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...

Abstract The potential to actuate proportional flow control valves using piezoelectric ceramics or other smart materials has been investigated for a number of years. Although performance advantages compared to electromagnetic actuation have been demonstrated, a major obstacle has proven to be ferroelectric hysteresis, which is typically 20% for a piezoelectric actuator. In this paper, a detaile...

Echocardiographic findings in five patients with pulmonary embolism were studied. Tricuspid echocardiograms showed abnormalities in valve motion, that is a monophasic triangular wave during diastole in all the patients as well as an increased dimension of the right ventricle. An "a' dip of the pulmonary valve echocardiogram was also recognised in all five. Later tricuspid echocardiograms regain...

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 throttle is a component that determines the amount of airflow into combustion chamber. latest in-vehicle technology makes it possible to adjust fly valve electronically. electronic system adjusts angle size by comparing predetermined setpoints. In research, designs are based on existing models. model uses stepper motor drive. Electronic control using microcontroller with proportional-integr...

By examining the dynamics of a popular type of two-stage electronic proportional valve, this paper addresses its performance limitations, with both cautions in control implementation and suggestions in valve design. While several benefits do exist, there are limitations to the closed loop performance of the valve when it is included in a valvecontrolled electrohydraulic system. These limitation...

Cerebral and retinal ischemic events have been described in mitral valve prolapse. To determine whether platelets play a part in the pathogenesis of thromboembolism we studied 29 patients with mitral valve prolapse, including nine (group I) with thromboembolism (cerebral, retinal and deep venous), eight (group II) with transient visual obscurations and 12 (group III) with neither thromboembolis...