This study presents an experimental investigation of a piston engine driven by compressed air. The compressed air engine was a modified 100 cm 3 internal combustion engine obtained from a motorcycle manufacturer. The experiments in this study used a test bench to examine the power performance and pressure/temperature variations of the compressed air engine at pressures ranging from 5 to 9 bar (...

To the Editor: Bob Colwell’s discussion of lift (“Leave Bernoulli Out of This,” At Random, May 2003, pp. 10-12) is better informed than many elementary texts on the subject, but it leaves out a more interesting question about how wings fly. Colwell points out the errors in the usual explanation—the one that depends on a wing’s greater curvature on top. His excellent counterexamples are that fla...

We show by computational solution of the incompressible Navier-Stokes equations with friction force boundary conditions, that the classical inviscid circulation theory by Kutta-Zhukovsky for lift of a wing and laminar viscous boundary layer theory by Prandtl for drag, which have dominated 20th century flight mechanics, do not correctly describe the real turbulent airflow around a wing. We show ...

We present a new mathematical theory explaning the mircale of flight which is fundamentally different from the existing theory by Kutta-ZhukovskyPrandtl formed 100 year ago. The new theory is based a new resolution of d’Alembert’s paradox showing that slightly viscous bluff body flow can be viewed as zero-drag/lift potential flow modified by a specific separation instability into turbulent flow...

An 80-year-old man with a history of en bloc resection of squamous cell carcinoma of the hard palate (T4aN0M0) was performed a lateral-window sinus lift of the edentulous area of the left maxillary molar region to facilitate future placement of dental implants.Two hours after the surgery, the patient complained of sudden malar swelling. Marked swelling was present from the left infraorbital reg...

For a century, researchers have used the standard lift coefficient C(L) to evaluate the lift, L, generated by fixed wings over an area S against dynamic pressure, ½ρv(2), where v is the effective velocity of the wing. Because the lift coefficient was developed initially for fixed wings in steady flow, its application to other lifting systems requires either simplifying assumptions or complex ad...

Large numbers of Mesenchymal stem/stromal cells (MSCs) are required for clinical relevant doses to treat a number of diseases. To economically manufacture these MSCs, an automated bioreactor system will be required. Herein we describe the development of a scalable closed-system, packed bed bioreactor suitable for large-scale MSCs expansion. The packed bed was formed from fused polystyrene pelle...

AIMS To study the cellular growth and morphology of Yarrowia lipolytica W29 and its lipase and protease production under increased air pressures. METHODS AND RESULTS Batch cultures of the yeast were conducted in a pressurized bioreactor at 4 and 8 bar of air pressure and the cellular behaviour was compared with cultures at atmospheric pressure. No inhibition of cellular growth was observed by...