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Computations were performed to study the three-dimensional flow and heat transfer in a U-shaped duct of square cross section under rotating and non-rotating conditions. The parameters investigated were two rotation numbers (0, 0.24) and smooth versus ribbed walls at a Reynolds number of 25,000, a density ratio of 0.13, and an inlet Mach number of 0.05. Results are presented for streamlines, velocity vector fields, and contours of Mach number, pressure, temperature, and Nusselt numbers. These results show how fluid flow in a U-duct evolves from a unidirectional one to one with convoluted secondary flows because of Coriolis force, centrifugal buoyancy, staggered inclined ribs, and a 180 deg bend. These results also show how the nature of the fluid flow affects surface heat transfer. The computations are based on the ensemble-averaged conservation equations of mass, momentum (compressible Navier-Stokes), and energy closed by the low Reynolds number SST turbulence model. Solutions were generated by a cell-centered finite-volume method that uses second-order flux-difference splitting and a diagonalized alternating-direction implicit scheme with local time stepping and V-cycle multigrid.

The pharmacokinetics of ciprofloxacin, administered orally as a 250-mg tablet were compared in 10 young (age 20–30 years) and 10 elderly (age 60–73 years) healthy volunteers. The time to peak serum concentrations was about 80 min in both age groups, although the maximum concentration attained was significantly greater in the old (1.7mg/l) than the young (1.2 mg/l). Area under the plasma concentration-time curve, corrected for body weight, was on average 48% greater in the elderly, but the mean terminal elimination half-life was not significantly different, averaging 4.3 h in the old and 3.7 h in the young. Overall 24-hour urinary recovery in both age groups was comparable. The differences may be explained by a reduced volume of distribution of ciprofloxacin in old age and do not suggest a general need for significant dose alteration in the elderly.

The Coaguchek was superior to the ProTime Microcoagulation System in accuracy, clinical correlation, and ease of use. The study also showed that patients preferred capillary blood sampling by finger puncture over venipuncture for INR monitoring.