The objective of this paper is to report the state-of-the-art of unsteady pressure measurements in pumps. Though optical techniques seem in some aspects more attracting, unsteady pressure measurements can give a detailed insight in static as well as dynamic operating behaviour of pumps. A brief description of wall mounted pressure transducers and of probes fitted with miniature pressure transdu...

the aim of this research is performance evaluation of reverse osmosis method for treatment of ion exchange resins regeneration wastewater from a petrochemical complex in iran. currently this wastewater is discharged to evaporation lagoons after neutralization. thus, we need to set up a pilot plant which has membrane cell for treatment performance evaluation of three kinds of reverse osmosis mem...

Pulse pressure velocity measurements (PPV) may be a source of useful information on artery state. A 2007 guideline of the European Society of Hypertension recommends assessing arterial stiffness in patients with arterial hypertension, by measuring the PPV. Mechanical changes in the cardiovascular tree involved in the blood ejection have been measured at the thorax level and on the wrist using i...

The relationship between the velocity of the cerebral circulation and the cerebral blood flow was explored at varying levels of PaCO(2), systemic arterial pressure, intracranial pressure, and perfusion pressure, using radioisotope techniques in baboons. Only at low flow rates did velocity increase with flow, and then non-linearly; at high rates velocity increased progressively less. Changes in ...

In this paper computational analysis of pressure and velocity in coal combustion system using the fluent software is analysed. The combustion of coal is used in circulating fluidized bed combustion system. This work is concerned about gas–solid two-phase mixtures flowing upwards through the fast beds. The type of information resulting from various ways of analyzing the pressure variations and t...

Cf = skin friction coefficient CD = drag coefficient CDf = friction drag coefficient CDp = pressure drag coefficient h = step height M0 = freestream Mach number Patm = atmospheric pressure Pi = stagnation pressure Re = freestream Reynolds number Ti = stagnation temperature U = velocity U = normalized velocity Uτ = friction velocity X = longitudinal coordinate Z = vertical coordinate Z = normali...

BACKGROUND AND PURPOSE Transcranial Doppler measurements of blood flow velocity permit an assessment of variations in intracranial hemodynamics in response to acute arterial pressure variations. The purpose of this study was to scan healthy volunteers and patients with autonomic failure for differences in cerebral hemodynamic patterns under an acute hypotensive stimulus. METHODS We used trans...

To determine the dependence of cerebral blood flow (CBF) on arterial pressure over prolonged time periods, we measured beat-to-beat changes in mean CBF velocity in the middle cerebral artery (transcranial Doppler) and mean arterial pressure (Finapres) continuously for 2 h in six healthy subjects (5 men and 1 woman, 18-40 yr old) during supine rest. Fluctuations in velocity and pressure were qua...

The aim of this study was to evaluate selected lipid-related and vascular factors and their effect on retrobulbar hemodynamics in glaucoma. Fifty-six patients with primary open angle glaucoma (POAG) [POAG group; mean age 68.32 years (SD±0.21)] and 54 patients in control group [CG, mean age 68.1 years (SD±5.34)] were examined. Peak systolic velocity, end-diastolic velocity, mean velocity, pulsat...