Incompressible high-Reynolds-number flows around a circular cylinder are analyzed by direct integration of the Navier-Stokes equations using finite-difference method. A generalized coordinate system is used so that a sufficient number of grid points are distributed in the boundary layer and the wake. A numerical scheme which suppresses non-linear instability for calculations of high-Reynolds-number flows is developed. The computation of an impulsively started flow at Re = 1200 is compared with corresponding experimental observations, and excellent agreements are obtained.A series of computations are carried out on the flow around a circular cylinder with surface roughness. The height of the roughness in these computations is 0.5% of the diameter. The range of Reynolds numbers is from 10] to 10 5 ; no turbulence model is employed. Sharp reduction of drag coefficient is observed near Re = 2 X 10 4 , which indicates that the critical Reynolds number is captured in the present computation.

Investigations have been made of three-dimensional flows of an incompressible viscous fluid in a square cubic cavity. The flows are driven by the sliding upper surface of the cavity. Numerical solutions are obtained by directly integrating the full, three-dimensional, time-dependent Navier-Stokes equations. The three-dimensional flow structure is examined in detail over a wide range of the Reynolds number Re. One primary finding of these three-dimensional numerical simulations indicates that steady solutions are attained at lower values of Re, but the flow becomes unsteady at higher values, say, when Re exceeds approximately 2000. Due to the profound influence of the endwall effects, three-dimensional flows show substantial differences from two-dimensional solutions: for two-dimensional flow situations, steady solutions are known to exist for up to Re ~10000. The three-dimensional flow structure displays qualitatively distinct features in the low-Re and high-Re regimes. The demarcation separating these two regimes appears to lie in the neighborhood of Re = 2000-3000. One principal characteristic is that the Taylor-Gortler-hkc vortices are discernible for the high-Re regimes, although these have not been clearly captured in the numerical results for the low-Re regimes. Critical assessments of the present numerical results have been made by cross-checking the data with the available experimental measurements for three-dimensional cavity flows. The comparisons demonstrate broad qualitative agreement between the present numerical computational results and the laboratory measurement data.

Fluorescence-based immunosensors serve a vital role in biotechnology and diagnostic and therapeutic applications. Our group recently developed a unique fluoroimmunosensor named Quenchbody (Q-body) that operates based on the principle of quenching and the antigen-dependent release of fluorophore, which is incorporated to a recombinant antibody fragment, either the single-chain Fv (scFv) or the Fab fragment of an antibody, using a cell-free transcription-translation system. With the objective of extending the functionality and diversity of the Q-body, here we attempted to make Q-bodies by labeling the recombinant scFv, which was prepared from E. coli using several commercially available dye-maleimides. As a result, we reproducibly obtained larger amounts of antiosteocalcin Q-bodies, with an improved yield and cost-efficiency compared with those obtained from a conventional cell-free system. The fluorescence intensity of each Q-body, including that labeled with newly tested rhodamine red, was significantly increased in the presence of an antigen with a low detection limit, although some differences in response were observed for the dye with different spacer lengths between dye and maleimide. The results indicate the Q-body’s applicability as a powerful multicolored sensor, with a potential to simultaneously monitor multiple targets in a sample.

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