The flow of granular material in rotating tumblers is confined to a thin flowing layer at the free surface in which the particle velocity is primarily streamwise, perpendicular to the axis of rotation, with minimal axial motion. Particle tracking velocimetry was used to measure the surface velocity for 1 and 2 mm glass particles and sand in cylindrical tumblers of various diameters, lengths, an...

BACKGROUND The factors that influence pulsatile ocular blood flow (POBF) were evaluated in normal subjects. METHODS POBF was measured in 80 normal subjects using Langham OBF computerised tonometry. The effect of age, systolic and diastolic blood pressure, refractive error, intraocular pressure, and axial length on POBF was evaluated using multiple regression analysis. RESULTS The mean (SD) ...

Ever increasing demand of higher pressure ratio of aero-engine compressors has always been hindered by two distinct aerodynamic instabilities. The first known as surge is; large one dimensional periodic mass flow fluctuation through the compressor, which involves the entire pumping system including compressor, ducting, plenum and throttle. The second is the rotating stall which can be character...

in high-pressure axial turbines, when the fluid mass flow is low, the supersonic blades are being used to obtain a high specific work output. to prevent losses due to low blade aspect ratio, the turbine is used in partial admission conditions. the turbine stator is a group of convergence-divergence nozzles that provides the supersonic flow. the design of these nozzles is important, because ther...

Tip vortex cavitation is one of well known patterns of cavitation phenomenon which occurs in axial pumps. This pattern of cavitation occurs due to pressure difference between the pressure and suction sides of blades of an axial pump. Since the pressure in the pressure side of the blade is higher than the pressure in its suction side, thus a very small portion of liquid flow flows back from pres...

Instead of pulsatile ventricular assist devices an increasing number of nonpulsatile ventricular assist devices are introduced to clinical practice. The different flow characteristics of this new technique lead to alteration in shear stress on blood components, which may affect the coagulation system. Repeated von Willebrand factor analyses were performed in a patient who first was implanted wi...