We compared density estimates for marine birds off central California from simultaneous aerial and boat-based surveys, with a special emphasis on Marbled Murrelets Brachyramphus marmoratus. We surveyed 44 eight-kilometer transects in nearshore waters of Monterey Bay, California, from December 2005 through March 2006. We found that density estimates of all birds combined and of Western Aechmopho...

Squeeze film dampers are widely used in aircraft engines, land-based gas turbines, and other rotating machines to improve system damping. They often have entrained air within the oil film, which is usually not taken into account in rotordynamics analysis due to lack of good formulations of the effects involved. The effects on the damping force calculation can be significant. This work presents ...

Air density uncertainty is usually evaluated as if its input quantities were uncorrelated and as if the mathematical model was linear. The present work takes the CIPM 81/91 formula as a starting point and proposes arguments in favour or against in order to take into account the correlation components and the higher order terms of the Taylor series expansion in the analysis of air density uncert...

BACKGROUND Exposure to air pollution is frequently associated with reductions in birth weight but results of available studies vary widely, possibly in part because of differences in air pollution metrics. Further insight is needed to identify the air pollution metrics most strongly and consistently associated with birth weight. METHODS We used a hospital-based obstetric database of more than...

Semianalytical solutions are developed for turbulent hydrogen-air plume. We derived analytical expressions for plume centerline variables radius, velocity, and density deficit in terms of a single universal function, called plume function. By combining the obtained analytical expressions of centerline variables with empirical Gaussian expressions of the mean variables, we obtain semianalytical ...