113 research outputs found
Remote sensing of bubble clouds in seawater
We report on the influence of submerged bubble clouds on the remote sensing
properties of water. We show that the optical effect of bubbles on radiative
transfer and on the estimate of the ocean color is significant. We present a
global map of the volume fraction of air in water derived from daily wind speed
data. This map, together with the parameterization of the microphysical
properties, shows the possible significance of bubble clouds on the albedo of
incoming solar energyComment: 17 pages, 6 Postscript figures, see also
http://atol.ucsd.edu/~pflatau publications for related papers. Q. J. Roy.
Met. Soc. in press 200
Monte Carlo Calculations for Liquid He at Negative Pressure
A Quadratic Diffusion Monte Carlo method has been used to obtain the equation
of state of liquid He including the negative pressure region down to the
spinodal point. The atomic interaction used is a renewed version (HFD-B(HE)) of
the Aziz potential, which reproduces quite accurately the features of the
experimental equation of state. The spinodal pressure has been calculated and
the behavior of the sound velociy around the spinodal density has been
analyzed.Comment: 10 pages, RevTex 3.0, with 4 PostScript figures include
Compression stress relaxation in carbon black reinforced HNBR at low temperatures
Findings of a study of stress relaxation behaviour of hydrogenated nitrile butadiene rubber (HNBR) at nominal compressive strains up to 0.4 and temperatures above and below the glass transition temperature Tg are reported. Two formulations of a model HNBR with 36% acrylonitrile content and carbon black (CB) loading of 0 and 50 phr were investigated. The relaxation function of HNBR is found to be independent of strain at temperatures right above the Tg or at times longer than 10−3 s for the deformations employed. CB imparts higher long-term stiffness and also larger relaxation strength at times longer than 10−4 s to the HNBR, but it does not affect the relaxation behaviour of the rubber in the time span from 10−3 – 104 s. In addition, the relationship between the strain energy function of HNBR and temperature is demonstrated to have a complex concave-downward shape which is affected by two competing contributions of entropy elasticity and the stress relaxation.acceptedVersio
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