in a novel dual bed reactor fischer-tropsch synthesis was studied by using two diffrent cobalt catalysts. an alkali-promoted cobalt catalyst was used in the first bed of a fixed-bed reactor followed by a rutenuim promoted cobalt catalyst in the second bed. the activity, product selectivity and accelerated deactivation of the system were assessed and compared with a conventional single bed react...

Pressure control valve (PCV) is implemented in internal combustion engine to regulate crankcase pressure. In this study, the performance of a diaphragm PCV valve is investigated numerically and experimentally. Firstly, numerical simulation is carried out using commercial code to predict the flow and pressure distribution inside the valve. Furthermore, downstream and upstream pressure of the val...

Background Expert consensus statements on management of implantable cardioverter defibrillators (ICDs) emphasize the importance of having discussions about deactivation before and after implantation. These statements were developed with limited patient input. The purpose of this study was to identify the factors associated with patients' experiences of end-of-life discussions, attitudes towards...

Abstract The performance of pumps installed in pumping stations depends greatly on vortex formation at pipe intakes. Using numerical simulations and experimental methods, this study focuses water intake system a station under the tidal conditions Bahmanshir River. consisted suction fine screen. Realizable k – ε turbulence model together with volume fluid (VOF) two-phase (water–air) are used to ...

The main purpose of this paper is to study various configurations of a magnetorheological (MR) damper valve and to evaluate their performance indices typically dynamic range, valve ratio, inductive time constant and pressure drop. It is known that these performance indices (PI) of the damper depend upon the magnetic circuit design of the valve. Hence, nine valve configurations are considered fo...

prolapsed mitral valve syndrome is a common, benign disorder with prevalence of %0.3-6 in population. this syndrome also is known as barlows syndrome and flaapy mitral valve syndrome. prolapsed mitral valve is the dropping of one or two mitral valve leaflet(s) into the left atrium during ventricular systole. this malformation leads to incomplete closing of mitral valve and regurgitates the bloo...

Reducing power consumption has become one of the biggest challenges in VLSI design. In control-flow intensive designs like networking and controller applications the largest fraction of power consumption in CMOS is caused by signal switches. The presented approach addresses the reduction of switching activity. This is basically done by state assignment concerning a given user-specified input pa...

Spark-ignited internal combustion engines are known to exhibit a decreased brake efficiency in part-load operation. Similarly cylinder deactivation, the x-stroke operation presented this paper is an adjustable form of skip-cycle It effective measure increase engine, which has be equipped with variable valve train enable feature. This presents optimization procedure for exhaust timings applicabl...

OBJECTIVES Examination of sensorimotor activation alone in multiple sclerosis (MS) patients may not yield a comprehensive view of cerebral response to task stimulation. Additional information may be obtained by examining the negative BOLD response (deactivation). Aim of this work was to characterize activation and deactivation patterns during passive hand movements in MS patients. METHODS 13 ...