in this paper, convection heat transfer of al2o3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. for each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. the governing equations in steady state and axisymme...

Experiments previously reported from this laboratory (1) have shown that less than 1 per cent of the “total diazo” value of the blood is actually made up of phenols, the reactive substances being almost exclusively etherinsoluble and presumably nitrogenous in nature1 (2). In the present work, an attempt was made to develop more specific methods for the determination of the various groups of uri...

in order to increase the efficiency of the conveyance of the granular solids, a new experimental set-up is designed. the test rig has longitudinal trapezoidal slots in its conveying pipes. through experimentation, a correlation for friction factor in terms of solid mass flow rate, fluid flow rate and froude number is presented. it is shown that the mixture friction factor for pipes with inner t...

In this paper, the scale effects are specifically addressed by conducting experiments with air flow in different microtubes. Three stainless steel tubes of 962, 308, and 83 μm inner diameter (ID) are investigated for friction factor, and the first two are investigated for heat transfer. Viscous heating effects are studied in the laminar as well as turbulent flow regimes by varying the air flow ...

Hydroforming is one kind of plasticity working, which can be used to increase the diameter, to change the geometry, or to expand the outer walls of cylindrical shells or tubes. The forming principle of hydroforming is by using a die to constrain the outer geometry of a tube and then pumping high pressure oil into the inner tube, so as to force part of the tube to flow into the die cavity. In or...

INTRODUCTION Tracheostomy is a common airway procedure for life support. The fracture of the tracheostomy tube is a rare complication. We report a case of a 14-year-old boy whose fractured stainless steel tracheostomy tube dislodged into the tracheobronchial tree. We include a literature review and proposed recommendations for tracheostomy care. CASE PRESENTATION A 14-year-old Thai boy who ha...

Flow systems for precise and accurate coulometric determinations of ions that were developed on the basis of electrolytic ion transfer at the aqueous|organic solution (W|O) interface are reviewed. The electrolysis cell in the system is composed of a porous poly(tetrafluoroethylene) tube (1.0 mm inner diameter), a metal wire (0.8 mm diameter) inserted into the tube, O into which the tube is imme...

The stability of supercritical Couette flow has been studied extensively, but few measurements of the velocity field of flow have been made. Particle image velocimetry (PIV) was used to measure the axial and radial velocities in a meridional plane for non-wavy and wavy Taylor–Couette flow in the annulus between a rotating inner cylinder and a fixed outer cylinder with fixed end conditions. The ...