This case series should alert the physicians to the possibility of pyogenic sacroiliitis and the difference between paediatric and adult patients.

In this paper, the drag force on a sphere moving constantly along the centerline of a circular pipe filled with viscous fluid (the falling-sphere problem) under low Reynolds number condition is investigated via numerical calculation.The incompressible Navier-Stokes equations are formulated in a pseudocompressibility form. The numerical scheme makes use of finite-volume method and the numerical flux terms are evaluated using the Total-Variation Diminishing (TVD) strategy commonly applied to the compressible flow. Steady solution is obtained by marching (iterating) in time until the artificial time derivative of pressure term in the continuity equation drops to zero.In the calculation, six different Reynolds number (Re) ranging from 0.1 to 1 and seven different pipeto-sphere diameter ratios (D/d) ranging from 5 to 40 are selected to study the pipe-wall effect.In each case, the drag force on the sphere is evaluated and the results are compared with the existing approximate theoretical values derived from correcting the Stokes' formula. Both results agree in trend, but with noticeable deviation in values, particularly for cases with large pipe-to-sphere diameter ratios. The deviation is due to the fact that theoretical values were based on the solution to the linearized Navier-Stokes equations (Stokes' creeping-flow equations), while the fully nonlinear form of the Navier-Stokes equations are adopted in the present calculations. Finally, a least-square regression technique is applied to collapse the calculated results into a single expression exhibiting the functional relationship between the drag force, Reynolds number (Re), and the pipe-to-sphere diameter ratio (D/d).

In considering transport layer protocol for multimedia applications in high speed networks, several characteristics of multimedia applications have to be considered. These characteristics include high speed transmission capability, real-time constraints, large bandwidth required by applications, and packet lost of some percentage is acceptable in some multimedia applications. In this paper, we propose a transport layer protocol for high speed multimedia applications, namely MHTP (Multimedia High-speed Transport Protocol), to resolve problems we will face in interworking multimedia systems using high speed networks.