Consider the three-dimensional flow of a viscous Newtonian fluid upon an arbitrarily curved substrate when the fluid film is thin as occurs in many draining, coating and biological flows. We drive the lubrication model of the dynamics of the film expressed in terms of the film thickness. The comprehensive model accurately includes the effects of the curvature of the substrate, via a physical multiple-scale approach, and gravity and inertia, via more rigorous centre manifold techniques. This new approach theoretically supports the use of the model over a wide range of parameters and provides a sound basis for further development of lubrication models. Numerical simulations exhibit some generic features of the dynamics of such thin fluid films on substrates with complex curvature: we here simulate a film thinning at a corner, the flow around a torus, and draining of a film down a cylinder. The last is more accurate than other lubrication models. The model derived here describes well thinfilm dynamics over a wide range of parameter regimes.

Small scale experiments were performed to investigate the condensation process and hydrodynamic pressure oscillations when steam was discharged into a subcooled water pool. The dynamic behavior of subsonic jets, differed from that of sonic jets. The interfacial motion of a subsonic jet was periodic, composed by three intervals: bubble growth, bubble translation, and bubble separation (necking). The condensation rate for each interval was governed by different processes. The pressure transient of the subsonic jet was marked by periodic impulses, originated by the necking process. Of the intensive parameters studied, pool subcooling exhibited the largest influence on dynamic behavior. The pulse frequency and intensity were found to be best fit by correlations involving the Jacob number and the Reynolds number.

During the Bremerhaven Workshop non-overtly diseased female dab Limanda lirnanda, 17 to 27 cm in length, were sampled for detailed histopathology along a 200 km transect (Stns 3, 5, 6, 7, 8 & 9) extending out from the Elbe estuary region (Stn 3) to the northwestern region of the Dogger Bank (Stn 9) in the southern North Sea. During the period March 12 to 30, 1990, approximately 20 fish were examined from each of the above stations Histopathological changes seen that were considered to be consistent with adverse exposure to xenobiotic compounds were confined to the heart, liver and kidney. In the heart, the prevalence of myocardial vacuolation, suggestive of fatty change, was significantly higher (p < 0.05) in fish from Stn 3 compared to fish from all other stations. In the llver, the most important lesions seen were well-developed foci of cellular alteration, high mitotlc activity and high neutral lipid accumulation in livers of dab sampled from the most inshore station (Stn 3) compared to the reference station (Stn 7). Foci of cellular alteration and high neutral lipid accumulation were significantly greater ( p < 0.05) at Stn 3 compared to Stn 7. In the kidney, the prevalance of proteinaceous/cellular debris in Bowman's space of renal glomeruli was significantly greater ( p < 0.01) in fish from Stn 3 compared to fish from Stn 7 The high prevalence of foci of cellular alteration and high neutral lipid accumulation In hepatocytes in the liver of dab are consistent with the effects of adverse exposure to toxic xenobiotics. The other non-infectious changes seen in the liver, as well as those seen In the heart and kidney, are also consistent with xenobiotic exposure but other possible explanations are considered. The value of using detailed histopathology on small numbers of dab which appear grossly normal is clearly demonstrated.

The authors discuss the multiple resonances which often complicate the composite bar technique for measuring elastic moduli and internal friction. These are interpreted as resulting from mixing of vibrational modes of the bar. A model based on this interpretation gives results qualitatively similar to those observed experimentally.

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