Biomedical subjects
Publications and source records attributed to William V Meyer.
This special issue of Applied Optics contains research papers on photon correlation and scattering, many of which were presented at the OSA Topical Meeting that was held 16-18 August 2004.
We describe an experimental breadboard developed for the investigation of nonequilibrium fluctuations induced by macroscopic temperature and concentration gradients under microgravity conditions. Under these conditions the amplitude of the fluctuations diverges strongly for long wavelengths. The setup was developed at the University of Milan and at the University of California at Santa Barbara within the gradient-driven fluctuations experiment (GRADFLEX) project of the European Space Agency, in collaboration with the National Aeronautics and Space Administration. The apparatus uses a quantitative shadowgraph technique for characterization of the static power spectrum of the fluctuations S(q) and the measurement of their dynamics. We present preliminary experimental results for S(q) obtained in the presence of gravity for gradient-driven fluctuations for two cases, those induced in a liquid mixture with a concentration gradient produced by the Soret effect and those induced in a single-component fluid by a temperature gradient.
Measuring the surface response function of a fluid allows us to ascertain many of its properties. Simplified surface response functions are presented for several interface conditions, including (a) a thin-film between two fluids of infinite extent, (b) the newly derived fluid-fluid interface between finite boundaries, and (c) the traditional fluid-fluid interface between infinite boundaries. The finite-boundary derivation indicates that wall effects are very short range. This portends that the effects of external vibrations, which traditionally make this measurement challenging, can be mitigated by scattering from thin fluid layers.